Clothing Comfort

1
Introduction to clothing comfort

1.1

Need and selection of clothing

The basic needs of human are food, clothing and shelter. After fulfilling
the first need of food, a person looks for the second important need, i.e.
clothing. In the present day society, we expect much more from clothing
than to satisfy our basic need. In most societies the clothing is for the
purpose of expressing wealth, status, occupation, age, occasion, gender,
etc [1]. There are various factors which influence the selection of clothing
type. Figure 1.1 illustrates the important factors which influence the
selection of clothing. It is evident from Figure 1.1 that the factors which
influence the selection of clothing can be divided broadly into four major
groups, i.e. social factor, economic factor, environmental factor and
physical factor. All these factors play significant roles in selection of
clothing of a person.
The social factors include the place where a person lives (urban or rural
area), cultural background of person, gender, occupation, occasion, social
status, etc. Depending on the place where a person lives, the clothing pattern
changes. In urban area, due to close cultural interactions between the
various sections of people, the clothing pattern becomes more cosmopolitan
in nature. But on the other hand the rural clothing is more influenced by
the regional factors. Similarly, clothing is also influenced by cultural
background and upbringing of a person. The upbringing influences the
taste of a person toward the clothing significantly. The modern society
does not believe in gender biasness and strongly oppose this. But, are we
ready to accept this to be applied while selecting clothing? Except few
exceptions, we are still comfortable in maintaining differences in male
and female clothing. In some cases a person selects his clothing depending
on the occupational requirement. For example, one can easily make out
the difference between a police and a common man depending on his
clothing, or in a hospital a nurse can be easily identified based on her
clothing. We generally prefer to wear different clothing depending on the
occasion, namely formal wear, casual wear, etc. A person generally prefers

1

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Science in clothing comfort
Factors for clothing selection

Social factors

Socioeconomic
condition

Economic
factors

Economic
status of an
individual

Environmental
factors

Availability of
technology /
raw materials

Climatic
condition

Age of a
person

Rural /
Urban

1.1

Cultural
background

Gender

Physiological
factors

Protection from
extreme
conditions

Health
condition of a
person

Occupation

Physical
structure
of body

Occasion

Unusual
places (deep
sea, space,
etc.)

Thermophysiological
responses of
body

Activity
level

Social status

Factors affecting the clothing selection.

to wear formal clothing in office, but the same person prefers casual wear
in leisure trip. It is also very common that a person tries to show his social
status through clothing, this trend prevails in every society since the
beginning of the civilization. The kings always tried to differentiate
themselves from the common man by wearing royal clothing.
Among the economic factors the important components are economic
condition of society, economic status of individual and availability of
technology or raw material. When the economic condition of society
changes that also reflects through clothing. It is well-known fact that the
general clothing pattern of rich and poor sectors of society differs and it
is obvious. This is also true for individual. Each individual selects clothing

Introduction to clothing comfort

3

depending on the affordability. Person also selects clothing to show his
economic status. The availability of a particular type of clothing depends
mainly on the availability of technology and raw materials. These two
factors are directly or indirectly dependent on the economic situation and
affordability of the society.
The environmental factors include climatic conditions (too cold, too
hot, raining, chilled wind, etc.), protection from extreme environment,
unusual places (space or under water), etc. Depending on the environmental
conditions the clothing need changes. Here, the performance factors are
the dominating parameters. One requires different clothing for different
climatic conditions. A person, going to extreme cold place, will definitely
like to protect himself from extreme cold by wearing extreme cold
protecting clothing. But, the same person will not use the same clothing in
normal environment. Depending on the climatic temperature the garments
are broadly divided into two categories, namely winter wear and summer
wear. Similarly, in rainy days we require clothing which is waterproof.
Clothing pattern also changes depending on the environmental threat, like
explosives, poisons, biological attacks, fire, radioactive or ultraviolet rays,
etc. Clothing also has to withstand falling and flying objects in certain
circumstances. Depending on the needs of unusual places, like deep under
sea, space etc., the type of clothing changes. In these places the special
type clothing are required for protection and specific performance.
The last and very important factor is physical conditions of a person,
which include age, condition of health of person, body structure,
physiological response of body, activity level, etc. The clothing pattern
changes with the age of person due to the psychological and physiological
changes with time. A child needs different type of clothing than an aged
person. Similarly the clothing need also changes with the physical health
of a person. Someone with specific problem with a particular fibre, like
allergy, irritation, would like to avoid wearing that particular clothing made
with these fibres. Clothing selection also depends on the physical built of
body, i.e. whether fat or thin, tall or short, etc. Person with special physical
need may require specific clothing. Physiological response of body varies
widely from person to person and so does the clothing need. In a given
environmental condition a particular person may feel more cold or heat or
sweat than others. This is due to the fact that the thermo-physiological
responses are different for different persons. The selection of clothing
also depends on the level of activity of a person. Under heavy activity the
human body generates more heat and sweat. The clothing, he wears, should
be able to dissipate and transmit the heat and sweat quickly to keep the
body heat under control. A sports person needs special sportswear
depending on the type of sports or a worker needs specific work wear
depending on his activity. People in challenging activities and sports could

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Science in clothing comfort

use smart clothing, that is, clothing that can sense the wearer’s condition
or situation and, in turn, modify its own structure to protect him or her, for
example to keep the body warm or cool.
A very well-known proverb says that “There is no such thing as bad
weather, only bad clothing”. Textiles always have played important roles
in well-being of a human being by protecting it from different adverse
environmental conditions and making him feel comfortable. Comfort
characteristic is an important functionality of clothing. Human thermophysiological comfort is associated with the thermal balance of human
body, which is highly dependent on metabolism rate, physical activities,
ambient temperature, and thermal and moisture transmission behaviour
of the worn clothing [2]. Clothing creates a microclimate between the
skin and the environment, which supports the body’s thermoregulatory
system to keep its temperature within a safe range, even when the
external environment temperature and humidity changes to quite an
extent.

1.2

Components of clothing comfort

Comfort is one of the most important aspects of clothing. Many attempts
have been made to define comfort, but a satisfactory definition is yet to be
obtained [3]. Comfort has been defined by many researchers in different
ways [4–6].
●
●
●
●

Comfort is influenced by the physiological reaction of the wearer.
Comfort is temperature regulation of the body.
Comfort is the absence of unpleasantness or discomfort.
Comfort is a state of pleasant psychological, physiological and
physical harmony between a human being and the environment. All
three aspects are equally important, since people feel uncomfortable
if any one of them is absent.

So, to know about the comfort characteristics of any particular fabric
or clothing, it is required to determine the different properties of the fabric
which have direct effects on the comfort.
Broadly there are four basic elements of clothing comfort, namely
thermo-physiological aspect, sensorial or tactile aspect, physiological
aspect and fitting comfort. The thermo-physiological comfort concerns
about the heat and moisture transmission characteristics through clothing,
i.e. transmission of heat, air, and moisture (liquid and vapour). The sensorial
or tactile comfort is related with the mechanical contact of the fabric with
skin, i.e. how a fabric or garment feels when it is worn next to the skin.
These are fabric handle or feel, softness, fullness, warm–cool touch, static
charge generation, flexing, pricking, itching, etc. The physiological comfort

Introduction to clothing comfort

5

depends on the aesthetic properties of fabric, i.e. drape, luster, colour,
crease, pilling, staining, etc. The fitting comfort deals with the size and fit
of clothing.
All the above comfort aspects are strongly correlated between them. In
clothing comfort, the most important factor is the movement of heat and
moisture (liquid and vapour) through clothing to maintain the thermal
equilibrium between human body and the environment.
According to Goldman [7] there are four primary factors in clothing
comfort, i.e. function, feel, fit and fashion. The function related to clothing
comfort parameters are thermal and moisture (liquid and vapour)
transmission, water absorbency, drying behaviour, etc. The thermal
transmission is a linear function of fabric thickness and relatively
independent of fibre characteristics. Thus the thermal transmission can be
controlled by the modification of yarn and fabric structures. Moisture
vapour permeability also controls thermal characteristics by evaporative
cooling phenomenon. The water transmission in liquid form, i.e. wicking,
depends mainly on the type of fibre, weave structure of fabric and the
finishes applied to the fabrics. The absorbency of water depends on fibre
type, finishes, weave and design of fabric. Although the wicking is
important, the amount of liquid that can be blotted away from the skin is
also very important. The drying behaviour depends on the type of fibre,
fabric and design of fabric. It is important because the ability of the body
heat to rapidly dry clothing and restore insulation is a critical factor for
survival.
The clothing comfort related to feel are broadly divided into two distinct
areas, namely the feel of clothing when held between the thumb and the
fingers and the feel of clothing by the wearer when worn in contact with
skin. Fit may incorporate factors from fashion, including concepts that
may be diametrically opposed to comfort [7]. The clothing fashion is related
with the psychological comfort.

1.3

Clothing comfort and wearer’s attitude

Comfort and satisfaction with clothing are influenced by both
characteristics of clothing as well as by attitudinal and psychological
perceptions of the wearer. The clothing characteristics include the
physical characteristics of the fibres and materials from which the
clothing is made, its tactile characteristics, design features of the clothing,
brand labels, information on fabric/garment care, price, etc [8]. The
wearer ’s attitudes towards clothing are influenced by the sensory
attributes of the clothing (softness/harshness, warm/cool touch etc.),
serviceability characteristic (e.g., durability, creasing, pilling) and most
importantly by its expected comfort and satisfaction related attributes.

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Science in clothing comfort

These attitudes may be gathered either through prior experiences with
the exactly same or similar type of clothing, or from information obtained
about the clothing through interpersonal, advertising or retail channels.
These attitudes toward either fabrics or items of clothing can significantly
affect the actual physiological comfort and other performance properties
of the clothing and can become the primary determinant of consumer
behaviour through their influence on behavioural intentions [9–11]. A
large number of studies have been reported on attitudes toward clothing
[12–15].
DeLong et al. [12] in their study to evaluate the consumer response to
apparels asked consumers to complete the sentence “When I think about
sweaters, I think about” without presenting any fabric samples or items
of clothing. They performed a content analysis of the words that
consumers used in order to assess the factors underlying the concept of
“sweater”. Byrne et al. [13], in their perception study on fibre types and
end use, used semantic differential grids to study consumer attitudes
toward silk, cotton, polyester and nylon for use in sport shirts and
undershirts. They have concluded that the consumer attitudes toward
the names of different fabrics were distinct and that the intended enduse greatly influenced perceptions of the adequacy of the fabric. During
the study on consumer preferences for natural, synthetic and blended
fibres, Forsythe and Thomas [14] observed that consumers have welldefined attitudes toward fibres and, with the exception of polyester/cotton
blends, these attitudes are consistent across demographic variables. The
attitudes of consumer about fabrics and clothing can be reliably assessed
with appropriate psychometric techniques applied to fabric or clothing
names.
Conjoint analysis technique is widely used by researcher for assessing
consumer attitudes toward clothing. This technique deals with the factors
related to the consumer attitudes and behavioural intentions by using multiattribute choice alternatives within a specified experimental design [8,
15, 16]. Using this technique, a survey had been conducted where
consumers are given a large set of multi-attribute choice alternatives.
Consumers choose or rate each combination of product variables on
attitudinal or behavioural dimensions of interest. The product attributes
are the dependent variable and by varying the attributes and their levels
according to a statistically determined experimental design, conjoint
analysis enables the researcher to “work backwards” from the choices/
ratings to uncover the relative importance of each factor to the consumer’s
decision process. Conjoint analysis has been used in clothing research to
study the relative importance of attributes related to the aesthetic
perceptions of garments [17].

Introduction to clothing comfort

1.4

Human–clothing interactions

1.4.1

Clothing as thermal barrier

7

Hindrance to the release of body heat
Fourt and Hollies [18] have described the clothing system as “a quasiphysiological system interacting with the body”. This means the
relationship between human body and clothing is a two-way process. Both
the clothing and the wearer perform their specific activities for others.
The clothing protects the wearer from the environmental hazards for which
it has been designed, whether they are heat, cold, fire, toxic agents or any
other thing. At the same time the clothing does some adverse things to the
wearer, e.g. by unwanted thermal insulation when it is not required, or by
hindering the free evaporation of sweat from skin. Presence of clothing
layer(s) prevents the efficient evaporative cooling of human body, which
is his sole defence against severe heat. Thus the wearer faces the unbearable
and dangerous conditions when he or she works near fire, like overheating,
dehydration, and sometime may also collapses.
In normal conditions, without any activity, the metabolic heat produced
by a normal person is nearly about 80 watts (same as an electric light
bulb!) and in the condition of high activity it can rapidly rise to more than
a kilowatt [19]. So, the human body requires an effective cooling system,
and physiological system of the body provides this cooling effect. This
metabolic heat load, mainly during high activity, poses a consistent threat
of overheating and the presence of clothing makes the threat even worse.
During high activity in extremely hot environment, e.g. worker in furnace,
firefighter, etc. gains hundreds of watts more from the surroundings in
addition to the metabolic heat generation. Sweating, which is an excellent
mechanism for cooling the skin by evaporating water from it, is the only
mechanism to reduce these great heat loads. On the other hand, the
excessive sweating may also results dehydration. During high activity
condition, in hot environment, a normal person can release sweat at the
rate of about 1 litre/hour. There are various linked mechanisms within the
human–clothing system which are essential to maintain the correct body
temperature and the failure of this link of heat transfer in any form causes
increase in body temperature and the person may feel sick or dizzy. The
most important mechanisms for effective heat transmission are:
●

●
●

all the metabolic heat produced should be carried to the inner body
surface (inner layer of skin) by the effective circulation of sweat;
the skin should be able to generate the necessary amount of sweat;
the generated sweat should get transmitted effectively (in liquid as
well as in vapour form) through clothing ensemble.

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Science in clothing comfort

One cannot adjust or change the first two mechanisms, but can definitely
control the third mechanism by proper clothing. When someone wears
excess number of clothing than what is required, he may feel overstressed
or overheated with normal activity.
Helps to retain body heat
Except very hot environmental conditions and at very high activity levels,
most of the environmental temperatures are below the human body
temperature and clothing is required to hinder the flow of body heat to
the atmosphere. So, in all these environmental conditions the heat flows
out from the human body to the atmosphere due to the temperature
difference, i.e. human body temperature is higher than the environment.
In normal room temperature, i.e. approximately 27±2°C, the wearer
requires minimum clothing layers to maintain the heat balance. The
wearer does not require too much thermal insulation in clothing as the
temperature difference between skin and the normal environment is low.
The heat, generated in the body, gets transmitted slowly through the
clothing and the open body surfaces (hands, arms, face, palms, etc.). As
the temperature of the atmosphere drops further (say below 10°C) the
rate of heat loss from body to atmosphere increases rapidly and the wearer
feels cold due to thermal imbalance. The best and easiest way to prevent
this body heat loss is to have certain insulating layer around the body,
and that is done by wearing some additional layers of clothing (which
also provide insulating still air layer). Under this condition, loss of body
heat through clothing drops significantly and little amount of heat loss
still takes place through some opening of body surface. In extreme cold
conditions (say below –20°C) the loss of body heat is prevented by
enhancing the thermal insulation of clothing and covering all the body
parts.

1.4.2

Mechanisms of enhancement of body heat
release

The symptoms of overheating or overstress due to excess number of
clothing rapidly disappear when the excess clothing is removed. The
transmission of body heat through clothing ensemble changes automatically
by different mechanisms. Activity of the wearer influences the heat
transmission characteristics of clothing. As soon as the wearer starts moving
or walking or running the thermal insulation of clothing reduces because
of a combination of forced air circulation between and through the layers
of clothing. This reduction in thermal transmission is further enhanced by
the typical bellows effect at various openings and also due to movement

Introduction to clothing comfort

9

the thermal insulation of the surrounding air reduces. During activity the
clothing gets wet from sweat which also causes the drop in the thermal
insulation. This automatic reduction in thermal insulation of clothing during
activity level may not be always sufficient and in those cases the wearer
becomes over-heated and sweats. This is due to the fact that the clothing
layers actually hinder evaporation of sweat. Majority of the generated sweat
wets the clothing in normal environment or in cold environment condenses
in the outer layers. In either case the sweat removes less heat from the
body than it does when it is able to evaporate from the skin, and additional
sweat therefore has to be secreted to maintain the heat balance.
Consequently the wearer is too hot while he is active, and when he later
rests he becomes chilled because of the reduced insulation of wet clothing
and the continuing evaporation of water from it [19]. The over-heating of
body can also be reduced by proper clothing design, i.e. by providing
effective ventilation in the clothing. The changes in clothing design may
be effected by:
(i) creating openings, to allow natural convection by chimney effect, at
various places in the clothing, e.g. neck, wrists, ankle and waist.
(ii) designing loose fit clothing to have free convection of air and free
interchange with outside air by means of a bellows effect.
(iii) providing full-length zippers in the clothing for specific applications.
(iv) avoiding the use of impermeable materials, whenever possible, can
further facilitate evaporative cooling.

1.4.3 Multilayer clothing system
Most of the performance clothing assemblies are generally not a single
layer system. These generally consist of a number of layers and each layer
performs its specific function. These layers are generally of three types,
i.e. inner layer, middle layer(s) and outer layer. A clothing ensemble that
should function with high requirements to comfort and protection must be
put together methodically from the inside out [20]. Figure 1.2 shows the
typical functions of individual layers of a three layer clothing system, where
the inner layer is generally an underwear which performs mainly the sweat
absorption, direct cooling of the skin, transmission and tactile functions;
the middle layers are generally shirt or sweater which helps still-air
entrapment to provide insulation, transmission etc.; and the outer is
primarily a shell layer for protection from extreme environmental factors,
like rain, wind, chemical, heat, radiation, etc.

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Science in clothing comfort

Thermal protection

Water
repellecny
Wind proof
Outer layer
Middle layer
Inner layer
Heat or Sweat (liquid or vapour)

1.2 Three-layer clothing system [21].

1.5

Understanding clothing comfort

1.5.1

Need and consumer trends

The basic and universal need of consumers in clothing is comfort and they
look for good feel and comfort when they buy clothing and other textile
materials. Clothing is very important in our life that we use everyday to
obtain physiological and psychological comfort and also to ensure physical
conditions around our body suitable for survival. Therefore, it is extremely
important for the survival of human beings and improvement of the quality
of our life to have good understanding of the fundamentals of clothing
comfort. From the viewpoint of the manufacturers of clothing and textile
materials, understanding of clothing comfort has substantial financial
implications in the effort to satisfy the needs and wants of consumers in
order to obtain sustainable competitive advantages in modern consumer
markets. Consumer always expects some additional functional qualities
from the clothes they purchase. Clothing is manufactured in a wide range
of thermal, tactile and physical properties to meet consumer needs.
Depending on the needs and expectations of the consumers, the clothing
and textile manufacturers provide wide range of options to enhance human
comfort. For example, clothing made from blends and natural fibres are
preferred to man-made fibres for all comfort attributes except smoothness,
or woven fabrics are preferred to knits for smoothness, thickness and
openness. To understand the basics of clothing comfort, sensory tools as
well as the equipments to evaluate the comfort related characteristics of
textile materials have been developed. Large number of studies has been
carried out and many equipment are developed in the textile and clothing
area such as mechanical, thermal and surface testing, so as to evaluate the
related physical properties, but the links between measurement and the
consumer feeling of comfort are still difficult to establish.

Introduction to clothing comfort

11

Consumers want everything from the clothing, i.e. it should look good,
feel good, perform well, would like their clothing to match with their chosen
attitudes, roles and images. Consumers are now allowing touch, smell,
intuition, and emotion to influence their decision on clothing selection
more than their aesthetic sense. As a result, great importance is being
attributed to the wearing experience and thus comfort is being reinforced
as a key parameter in clothing. It is also true that requirements of consumers
on comfort changes with products and situations. Clearly, understanding
and satisfying the needs of consumer towards clothing products are crucial
for the long-term survival and growth of clothing and textile demand.
Understanding and enhancement of clothing comfort is definitely one of
the important issues.

1.5.2

Scientific approaches

To have proper understanding of the clothing comfort and to predict comfort
performance of clothing during wear, one needs integrated scientific
knowledge of physics, physiology, neurophysiology, and psychology of
comfort. In long-term perspective, it is very important to have proper
knowledge on clothing comfort to improve the quality of life and the survival
of human beings. The clothing and textile industries should take necessary
initiative in this area to achieve market leadership. Researchers identified
the psychological sensory attributes what consumer desire, which is
correlated with the technical parameters of clothing through psychophysical
perceptual trials. The clothing can be developed with specified technical
parameters to achieve certain level of psychophysical comfort. Li [22]
reported that there are five levels of understanding clothing comfort. The
important steps for scientific understanding of clothing comfort are market
research, wear trials, objective evaluation of clothing characteristics and
objective evaluation of fabric characteristics. The market research is generally
carried out by identification of target group, personal interviews and
consumer surveys to gather market information on the products. The wear
trials can be conducted either in the field in which the clothing are used or
in climatic chambers for psychological sensory study, consumer focus group
study and subjective evaluation of clothing. The objective evaluation of
clothing characteristics, e.g. thermal and moisture transmission are generally
done either on human subjects or thermal manikins. The objective evaluation
of fabric characteristics are carried out by testing transmission (moisture,
heat), handle, tactile and aesthetic characteristics of fabrics. The information
on clothing comfort requirements should flow from customer to technical
specifications of fabrics and clothing to have a new product that can satisfy
the requirements of consumers. On the other hand, one can predict the
consumer acceptability of particular clothing by proper understanding of

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Science in clothing comfort

fabric and clothing characteristics, physical and psychophysical mechanisms.
Using statistical and mathematical tools one can easily optimize the clothing
parameters as per the identified consumer’s requirements even before actual
production.

References
1.
2.
3.
4.
5.
6.
7.

8.

9.
10.

11.
12.

13.
14.

15.
16.
17.
18.
19.
20.
21.
22.

COATES J . F .,

‘From my perspective: The future of clothing’, Technological
Forecasting & Social Change 72, 101–110, 2005.
OLSCHEWSKI H . and BRUCK K ., ‘Cardiovascular and muscular factors related to
exercise after pre-cooling’, J. Appl. Physiol. 64, 803–811, 1988.
SLATER K ., ‘Comfort properties of textiles’, Text. Prog. 9(4), 1–42, 1977.
HATCH K . L ., Textile Science, West Publishing Company, New York, 1993.
SLATER K ., Human Comfort, Thomas Springfield, Illinois, 1985.
SLATER K ., ‘The assessment of comfort’, J. Text. Inst., 77, 157–171, 1986.
GOLDMAN R . F., ‘The four ‘Fs’ of clothing comfort’, Elsevier Ergonomics Book
Series: Environmental Ergonomics - The Ergonomics of Human Comfort, Health
and Performance in the Thermal Environment 3, 315–319, 2005.
SCHUTZ HOWARD G ., CARDELLO ARMAND V . and WINTERHALTER C ., ‘Perceptions of
fiber and fabric uses and the factors contributing to military clothing comfort
and satisfaction’, Textile Res. J. 75(3), 223–232, 2005.
SMITH J ., ‘Perceived comfort’, Text. Horiz. 9, 44–45, 1986.
SHIM S . and DRAKE M. F., ‘Consumer intention to purchase apparel by mail order:
beliefs, attitude, and decision process variables’, Cloth. Textiles Res. J. 9(1),
18–26, 1990.
WITTER B. S . and NOEL C ., ‘Apparel advertising: a study in consumer attitude
change, cloth’, Textile Res. J. 3(1), 34–40, 1984–85.
DELONG M. R., MINSHALL B . C . and LARNTZ K ., ‘Use of schema for evaluating
consumer response to an apparel product’, Cloth. Textiles Res. J. 5, 17–26,
1986.
BYRNE M. S ., GARDNER , A . D . W. and FRITZ , A . M., ‘Fiber types and end-uses: A
perceptual study’, J. Textile Inst. 84(2), 275–288, 1993.
FORSYTHE S . M. and THOMAS, J . B., ‘Natural, synthetic and blended fabric contents:
an investigation of consumer preferences and perceptions’, Cloth. Textiles Res.
J., 8(3) 60–64, 1989.
GREEN P . E . and SRINIVASAN, V ., ‘Conjoint analysis in consumer research: issues
and outlook’, J. Customer Res., 5 103–124, 1978.
GREEN P . E . and SRINIVASAN , V ., ‘A general approach to product design optimization
via conjoint analysis’, J. Marketing 45, 17–37, 1978.
ECKMAN M., ‘Attractiveness of men’s suits: the effect of aesthetic attributes and
consumer characteristics’, Cloth. Textiles Res. J. 15 (4), 193–202, 1997.
FOURT L . and HOLLIES N . R . S., Clothing: Comfort and Function, Dekker, New
York, 1970.
BUDD G . M., ‘Clothing physiology’, Fire Safety Journal 4, 77–81, 1981.
RUTH N ., Work clothing, International Journal of Industrial Ergonomics, 7, 77–
85, 1991.
DAS A., Objective evaluation of comfort characteristics of textiles, Seminar on comfort
in textiles, Department of Textile Technology, IIT Delhi, October 16, 2004.
LI Y ., The science of clothing comfort, Textile Progress 31(1/2), 2001.

2
Psychology and comfort

2.1

Psycho-physiological factors of clothing
comfort

The physiological factors of human body for expressing the human comfort
are average skin temperature, degree of skin wetness (indicated by electrical
conductivity at the body surface), rate of sweating, the amount of sweat,
sweat absorbed by clothing, and rate of heart beat. It is important to
correlate all the physiological parameters with contributing psychological
factors to predict the perceptions of comfort. Thermal effects contribute
extensively to the ‘comfort’ of an individual, complex physiological and
psychological factors collectively play an important role in defining this
complex quality with reference to clothing [1]. In fact, clothing comfort is
the psychological feeling of wearer who wears the clothing under different
environmental conditions. The factors influencing the clothing comfort
sensations of wearer can be divided broadly into three groups: (i) physical
factors (deals with the human–clothing–environment system); (ii) psychophysiological factors of the wearer; and (iii) psychological filters of the
brain. The comfort status of wearer depends on all these factors and their
complex interactions and synchronizations.
Figure 2.1 shows the interrelationships between the important physical
and physiological factors those control the clothing comfort. The figure
illustrates the process of how the subjective perception of overall comfort
is formulated. The physical processes provide different signals or stimuli
(e.g., warm/cool, touch, prick, pressure, wetness, etc.) to the sensory organs
of the human body. The human body receives all these stimuli and
subsequently generates neurophysiologic impulses. The neurophysiologic
impulses are then send to the brain to take corrective actions to adjust the
sweating rate, blood flow, and sometimes heat production, shivering, etc.
[2]. The brain, after receiving the sensory impulses, processes all these
impulses to generate the human subjective perception of various individual
sensations, and further evaluate and weigh them based on the past
experiences. The processes of evaluation and weighing are influenced by

13

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Science in clothing comfort

many factors such as physical, environmental, social, cultural, etc. The
clothing comfort is a human psychological perception related with clothing
ensemble, which is an outcome of complex linkages between individual
sensory stimuli received by brain, evaluation and weighing of all these
stimuli to formulate subjective perception of overall comfort based on
wear experience.

2.1 Important physical and physiological factors controlling the clothing comfort.

2.1.1

Psychological perceptions of clothing comfort

The wearers consider the comfort as one of the most important attributes
in their clothing ensembles, so there is a need to develop an in-depth
scientific understanding of the psychological perception of clothing
comfort sensations. The physical comfort is greatly influenced by tactile
and thermal sensations arising from contact between skin and the immediate
environment [3]. Comfort may be defined as pleasant state of physiological,
psychological and physical harmony between a human being and the
environment [4]. Comfort can also be defined as a holistic concept, which
is a state of multiple interactions of physical, physiological, and
psychological factors [5]. All these definitions only identify the factors
influencing the human psychological perceptions. Wong et al. [6] developed
a linear model based on artificial neural network predictions using three
major factors which affect the comfort perceptions, namely moisture related
factor, tactile sensations and thermal-fit comfort, and their relative weights

Psychology and comfort

15

to predict overall comfort perceptions. They have developed feed-forward
back-propagation neural network models to predict an overall comfort
perception from ten individual sensory perceptions (clammy, clingy, damp,
sticky, heavy, prickly, scratchy, fit, breathable and thermal). They have
reported a good agreement between predicted and actual clothing comfort
perceptions, which indicated that the neural network is an effective
technique for modelling the psychological perceptions of clothing sensory
comfort. They have further reported that the functions and interrelationships
of individual sensory perceptions and comfort are unknown.

2.1.2

Sensory perceptions of clothing comfort

Different types of sensations generated from clothing ensemble depend
mainly on the various combinations of type of clothing, type and level of
activities and the environmental conditions experienced by the wearer
during the activities. The most common clothing comfort related sensory
attributes are thermal, moisture, tactile, hand, and aesthetic experiences.
The experts in the field of sensory attributes can easily identify the
difference between the above attributes and suggest accordingly. But, it is
very important to identify some commonly recognized comfort attributes
of clothing among ordinary wearers, and what they are if they exist. When
the level of human activity or the temperature and humidity of microclimate
change the changes in various sensory perceptions, like warmth, chilliness,
scratchiness, dampness etc., can be very easily detected [7]. Strong
sensations can also be experienced, both indoors and outdoors, when mild
or heavy sweating occurred, and during modest excursions of warming or
chilling following the inception of sweating. There are many attributes
which describe the clothing comfort sensory perceptions of human. Some
of the important attributes are loose or tight, heavy or light, stiff or pliable,
sticky or non-sticky, absorbent or non- absorbent, cold or warm, pleasant
or clammy, dry or damp, pricky or non-pricky, rough or smooth and scratchy
or non-scratchy, etc. Some of these attributes do not give useful contribution
in prediction of clothing comforts. So, most important and established
attributes for subjective evaluation of sensory perceptions of clothing
comfort are course–fine, rough–smooth, stiff–pliable, harsh–soft, cool–
warm, hard–soft, and rustle–quiet, for expressing sensorial comfort. In
developing methodology for evaluation of fabric handle, Kawabata [8]
generated sensory attributes by letting a panel of expert judges (the Hand
Evaluation and Standardization Committee) judge the fabric handle and
asking them the reasons for their decisions. They identified terms such as
KOSHI (stiffness), NUMERI (smoothness), and SHARI (crispness) as
‘primary hand’ expressions.

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Science in clothing comfort

The investigation on physiological sensory responses to clothing, of
consumers living in different countries, revealed that the ratings of most
of the sensory attributes are significantly different between three types of
clothing, i.e. summer wear, winter wear, and sportswear. No significant
differences in rating of the sensory descriptors were found between male
and female respondents. The physiological sensory responses to clothing
which were considered in the study are snug, loose, stiff, lightweight,
staticky, non-absorbent, sticky, heavy, cold, damp, clammy, clingy, rough,
cool, hot, soft, warm, wet, prickly, itchy, chill, sultry, tickling, and raggy
[2]. The wearers themselves know best and they are capable of making
objective, quantitative and repeatable assessments of their sensations of
their clothing. Therefore, sensory attributes should come from the wearers
instead of experts or researchers.

2.2

Psychophysics and clothing comfort

2.2.1

Laws of psychophysics

Fechner, in 1860, originated psychophysics to describe the mathematical
relationship between the conscious experience of a sensation and an
external physical attributes [9]. According to his theory, if one knows the
mathematical form of the psychophysical relation between a physical
attribute and its corresponding sensation, he can measure psychological
attributes by measuring their physical factors. Therefore, psychophysics
is about the quantification of the strength of internal sensations, which
can be broadly defined as the quantification of sensory experience. The
strength of internal sensations has two aspects of indication, i.e. (i) the
assessment of human powers of signal identification and sensory
discrimination, and (ii) the calibration of subjectively perceived intensities
and other parameters of stimulation.
Weber, in 1834, [10] proposed that the threshold (i.e. the just noticeable
difference) of stimulus (ΔSp) are proportional to the magnitude of stimulus
Sp. This is known as Weber’s law and can be expressed as:
Sp/S p = K
(1)
where K is a constant indicating the power of a human being to detect
signals and discriminate sensations. This law holds good for many stimulus
attributes down to about the absolute threshold which is the smallest
magnitude of stimulus that can be perceived.
Fechner, in 1860, [9, 10] proposed using “just noticeable deference” as
a unit to measure internal sensation. Fechner assumed that sensation Rs
increases as the logarithm of physical stimulus magnitude Sp; this is called
Fechner’s law and can be described as:

Psychology and comfort

R s = K´logSp

17
(2)

where K´ is the constant determined by the stimulus threshold which
represents the lowest physical value evoking sensation and the deferential
threshold providing a subjective unit of sensory intensity. This law states
that sensation increases in arithmetic steps as the physical stimulus is
increased in logarithmic steps. Both Fechner’s law and Weber’s law of
psychophysics are related to each other.
Stevens, in 1953, [10] developed a method of estimation of the
relationship between subjectively perceived intensity and physical stimulus
strength. This method was applied to a large number of different stimulus
attributes. The results from each stimulus attribute generally follow the
following relationship,
R s = aS pb

(3)

where, ‘a’ is a scale factor and ‘b’ an exponent characteristics of the
attribute. This equation is known as Stevens’ power law.
All these laws of psychophysics indicate that there are fundamental
differences between the physical stimulus and the sensation that one
experiences. Weber’s law and Fechner’s law play some fundamental role
in sensory discrimination in terms of the ability to distinguish one stimulus
from another, but fail to provide a basis for measuring sensation. Stevens’
law proposes a power relation between physical stimulus magnitude and
internal sensation which provides a ‘direct’ measurement of sensation in
sensory judgment process.

2.2.2

Types of psychophysical scaling

Psychological scaling is a process of assigning numbers to characteristics
of objects or events, according to rules which reflects some aspects of
reality. Psychological scaling has been widely used in marketing research
to obtain consumers opinions and study their attitudes and preferences.
Assigning numbers does not always correspond to the real numbers that
are obtained from objective measurement in physical means. The numbers
cannot necessarily be added, subtracted, divided or multiplied. The numbers
are used as a symbol to represent certain characteristics and the rules
specifying how numbers are assigned to the characteristics to measure.
These rules may be arbitrary and changes as per the specific condition.
The rules governing how to assign numbers constitute the essential
criteria defining each scale. There are four types of scale of measurement:
nominal scale, ordinal scale, interval scale and ratio scale [11]. Moving
from nominal scale to ratio scales, the rules become more complex and
the kinds of arithmetic operations for which the numbers can be used are

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increased. Each scale exhibits symmetries and hence corresponds to a type
of symmetry group [12]. In fact, the four scales correspond to a descending
sequence of subgroups, e.g. the group for the nominal scale containing
the group for the next scale, i.e. the ordinal scale. Similarly, the group for
the ordinal scale contains the group for the interval scale, and the group
for the interval scale contains the group for the ratio scale. In other words,
the symmetries which are members of the set corresponding to the ratio
scale are also members of the set corresponding to the interval scale
although the latter contains additional symmetries as well, and so on, the
set corresponding to the nominal scale having the greatest number of
symmetries as members [13].
Nominal scales consist of numbers used to categorize objects. A nominal
number serves as a label for a class category. In a nominal scale, items are
sorted into classes with no quantitative information conveyed. Numbers
may be used in a nominal scale, but they are only used to indicate group
membership, e.g., the numbers on the jersey of a player in a hockey team
or one can assign 0 to male and 1 to female. The number 1 does not imply
superior position to number 0 or number on the jersey of a player generally
does not indicate the performance of player. The rules for nominal scales
are that all numbers of a class have the equal value. The only arithmetic
operation that can be performed on nominal data is the count in each
category. Nominal numbers cannot be added, subtracted, multiplied and
divided. The nominal scales only distinguish the objects or events on the
scale from things that are not on it. Due to its high degree of symmetry, it
conveys little information and is hence the weakest form of measurement.
For example, grading the students only in the form of pass or fail does not
convey much information about student performance than assigning grades
or exact percentile.
Ordinal scales comprise numbers or other symbols used to rank the
events or objects according to their characteristics and their relative position
in the characteristics. Ordinal data indicate the relative position of objects
on certain characteristics scales but not the magnitude of the differences
between the objects. A mode or median may be used, but not a mean. Nonparametric statistics can be applied to ordinal data. Some of the symmetries
in nominal scales disappear during the shifting of events or objects from
nominal to ordinal scales. This is because the ordinal scale is less
symmetrical than a nominal scale. For example, generally the top person
in an organization gets highest salary and the salary reduces according to
the hierarchy in the organization. But as long as the hierarchy is preserved,
there is no social significance in varying the salary in each level. Hence,
there are symmetries here as well, transformations which would make no
social difference. But there is less symmetry here than in nominal scales,

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19

since some transformations that would not socially matter in ordinal scales
do matter in nominal. For example, giving more salary to manager than
the president would be forbidden, or it would indicate a change in status.
The transition from ordinal scale to interval scale results in a reduction
of symmetries. In the interval scales the numbers are used to rank the
objects or events in such a way that numerically equal distances on the
interval scale represent equal distances in the characteristics of the objects
or event being measured. But both zero and their unit of measurement
are not fixed and are arbitrary. Therefore, interval data can indicate both
relative position of objects and the magnitudes of differences between
the objects on the characteristics being measured. The entire range of
statistics can be applied to interval scales. On an interval scale, one unit
represents the same magnitude as any other. For example, in Box and
Behnken [14] three-factors and three-level model the factors (independent
variables) are coded with –1, 0 and +1 for their three levels. In the actual
data the intervals in the factors are numerically same. Another example
is the measurement of temperature in centigrade scale. One degree
centigrade is warmer than 0°C degrees to the same extent as 2°C is
warmer than 1°C. Fiske [11] stated that “Equality matching relationships
resemble an interval scale in that people can not only specify who owes
what to whom, but also how much they owe”. On the basis of ordinal
scale, people keep track of imbalances or differences between each other
and try to maintain balance. Equality, following particular turn, strict
reciprocity is maintained strictly. Examples are voting, games that involve
equal turn-taking, and so on. There is less symmetry here than in the
case of ordinal scale. In interval scale, one must make sure that everyone
has the same thing, however, sameness is defined. This degree of
precision is lacking in ordinal scale [13].
A ratio scale is exactly like an interval scale, except that it has an absolute
0 point. For example, the kelvin temperature scale has absolute zero point
but the centigrade temperature scale measures the freezing point of water
defined as zero degrees Celsius and does not have absolute zero scale.
Ratio scales represent the numbers used to rank objects such that
numerically equal distances on the scale represent equal distances of the
characteristics measured and have a meaningful zero. Like interval scales,
entire range of statistics can be applied to ratio data. Ten degrees centigrade
is not twice as hot as 5°C, but 10 K is twice as hot as 5 K. In ratio scale,
people order their interactions according to a system of ratios and
proportions such as salary, rents, taxes, etc. This allows each individual or
group of like-minded people to decide how to act and evaluate actions
according to cost-benefit analysis [13].
All the above four types of psychological scales are important for better
understanding of psychology of clothing comfort. The nominal scales

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determine quality and have been used for categorization and classification
such as gender, age, and place of living. Ordinal scales determine equality
and relative position and have been used to obtain the rankings of fabrics
or clothing in consideration. The most frequently used scales are the interval
scales, which determine equality, relative position, magnitude of
differences and have been widely used to obtain the perception of various
attributes of clothing. The ratio scales are mainly applicable to the data
generated from physical instruments, which determine equality, relative
position and magnitude of difference with a meaningful zero.

2.2.3

Psychophysical scaling of clothing comfort

The tactile parameters, like prickliness, fabric itchiness, fabric stiffness,
fabric softness, fabric smoothness, roughness, scratchiness, etc., are
basically sensory comfort attributes, but the psychological comfort is not
a sensory attribute, because it is not associated directly with any single
human sense organ. The psychological clothing comfort is characterized
by emotion and affection, which is related with the liking towards particular
clothing. Thus, there is no underlying physical dimension of the stimulus
that varies continuously and is monotonic with the perception of comfort.
The same stimulus can generate altogether different comfort responses
from different individuals. As a result, it is not possible to define a comfort
scale based on physical standards that is valid for all users [15]. In general
the clothing comfort is characterized by emotional attributes, so the
judgment can be done effectively by untrained consumers instead of
experts. This requires a method for psychophysical scaling of clothing
comfort that is simple and easy to understand which do not require any
training or complex instructions. The ‘category scale’ is the most commonly
used subjective scale for rating comfort. This is characterized by a series
of verbally and/or number labelled points or descriptive categories, like
‘extremely comfortable’, ‘moderately comfortable’, ‘slightly comfortable’,
etc. In this type of scaling, a person can rate his subjective comfort
sensations by placing them into one of several descriptive categories. Since
less than five categories can result in a loss of discrimination sensitivity,
the number of categories is typically around seven to nine, or sometime it
can also be more [16, 17]. Due to the simplicity, versatility, and high
reliability the ‘category scales’ are widely used for measurement of
subjective clothing comfort and other psychological attributes.
Although there are many advantages, still there exist some critical
problems associated with the use of ‘category scales’. In case of a
numbered category scale, the numbers with equal intervals do not represent
equal subjective intervals [18]. In the labelled category scales, subjects
attend primarily to the word labels and not to the numbers [19]. In these

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21

cases, unless the verbal labels are chosen on the basis of extensive
evaluation process to verify that the differences between ‘slightly
comfortable’ and ‘moderately comfortable’ are the same as those between
‘moderately comfortable’ and ‘extremely comfortable’ the scale cannot
be considered to be an interval scale, but merely an order of comfort
sensation. Another common problem with category scales is that the
normal tendency of a person is to avoid the end categories; this is called
“category end effect”. This “category end effect” results in seven-point
category scales being functionally reduced to five-point scales after
eliminating two end points; and similarly the five-point scales is reduced
to three-point scales, and so on.
The recent developments in psychophysical methodology that enable
better quantification of both the descriptive aspects of tactile sensations
and the scaling of the emotional attributes of handle helped the researchers
in applying well-established psychophysical approaches to study the
sensory and comfort characteristics of clothing. After the development of
Kawabata instrumental evaluation systems [8, 20, 21] for measuring lowstress mechanical characteristics of fabrics, it has now become relatively
simple to measure many subjective attributes objectively. Combining the
psychophysical sensory methodology with the established instrumental
methods of fabric characterization now makes it possible to develop better
predictive relationships among sensory, instrumental and comfort
characteristics of clothing.

2.3

Wear trial techniques

Human being often uses hands to obtain tactile information, but much of
the tactile sensations come from parts of the body other than hands. This
suggests the necessity of study of the perception of clothing comfort in
actual wear situations. Therefore the wear trialing is an important technique
for clothing comfort research. Sensory clothing comfort perceptions are
primarily associated with skin sensory systems. In addition to this the
clothing comfort sensations involve various sensory channels from all the
five senses: visual, auditory, smell, taste and touch. A certain type of
clothing comfort sensation is generated under certain wear conditions with
a particular type of external stimuli and physical activity. The external
stimuli (heat, moisture, wind, etc.) and mechanical stimulation from fabric
to the skin (softness, scratchy, pricky, etc.) are normally generated under
specific combinations of physiological states (e.g. sweating rate), materials
used in the clothing, fitness of clothing and environmental conditions (e.g.,
temperature, humidity and air velocity).
Hollies et al. [22, 23, 25] proposed the wear trial technique to generate
reactions of wearer to any perceived discomfort sensations produced by

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Science in clothing comfort

different climatic conditions, and by alternating sweating and cooling off
conditions that might be encountered in actual wear of clothing. In the
wear trial experimental technique they also characterized the sensory
comfort of clothing, which included a number of components:
(i) Generation of sensory attributes with wearers.
(ii) Selection of particular testing conditions for effective analysis of
the perception of various sensations.
(iii) Designing attitude scales in the way of subjective rating sheets to
obtain various sensory responses to particular garments. The sheets
contain different comfort attributes (e.g., stiff, sticky, non-absorbent,
cold, damp, clammy, clingy, rough, scratchy, etc.) at different time
interval in particular environmental condition. The comfort intensity
was scaled at five different scales, i.e. 1 is totally uncomfortable and
5 is completely comfortable.
(iv) The wear trial was then conducted in controlled environments
chambers according to predetermined protocol.
(v) The wearers rated the garments for each comfort attribute separately
for different time interval.
(vi) All collected data were analyzed and the results were interpreted.
In a recent research study [24] warm and humid climatic conditions
were produced using a climatic chamber with precise control of air
temperature and humidity. In this study, different varieties of garments
were worn with six coverall types. Each test session was made up of five
individual evaluation periods, which yielded approximately 900 individual
evaluations. Comfort ratings were assessed on all test garments in each of
the five rating periods of the protocol. An evaluation form was designed
to record ratings of comfort and sensory properties for each of the five
periods. The scales used to assess overall comfort, thermal sensation, and
contact comfort sensations were recorded. During each evaluation period,
wearers were asked to indicate the number, on the designated rating scale,
that best described their perceived sensations. The wearers and the garments
were precisely weighed before and after completion of the wear trial
protocol to estimate the moisture loss from the body, and to determine the
amount of moisture accumulated in the test garments. During the wear
trial study the overall comfort sensations, thermal sensation and skin
contact comfort sensations of garments were rated by the wearers with
different terms and scales. The overall comfort sensations were expressed
in seven scales, i.e. 1 – Very uncomfortable, 2 – Uncomfortable, 3 – Slightly
uncomfortable, 4 – Neither comfortable nor uncomfortable, 5 – Slightly
comfortable, 6 – Comfortable and 7 – Very comfortable. Statistical
techniques have been adopted for data analysis.

Psychology and comfort

23

Wong et al. [26] used neural network technique in wear trial to predict
the human psychological perceptions of clothing sensory comfort. They have
selected twenty-two professional athletes as subjects to take part in the
psychological sensory cycling trial. The wear trials were conducted in an
environmentally controlled laboratory. Before the trial, athletes were
subjected to medical fitness examinations to ensure that they were able to
complete the experiment. They have chosen different commercial sportswear
in their study. Initially they invited the professional athletes for a pre-trial
before the formal trials to obtain training and understanding of the questions
and procedures involved. During each trial, each athlete was required to
shower upon arriving at the laboratory, then change into a test garment and
a pair of nylon shorts, and rest to equilibrium for 20 minutes. During the
wear trial the laboratory conditions were controlled at 15°C, 65% RH, and
an air velocity varying between 0.15 and 1.50 m/s. At the end of the
equilibrium period the athletes were asked to ride ergonomic bikes for 90
minutes under work loads maintaining their heart rates at 70% of their
estimated maxima. The athletes were asked to rate the sensory perceptions
(e.g., clammy, clingy, sticky, damp, heavy, prickly, scratchy, fit, breathable
and thermal) of the sportswear at different time interval, i.e. at the beginning,
after 30 minutes, after 60 minutes and after 90 minutes. The ratings by the
athletes were subsequently converted into 0–100 scales for all the sensory
perceptions except fit and thermal sensations. The fit and thermal sensations
were rescaled to the range from -50 to +50 because in these two perceptions
the wordings used in the scale’s two ends to describe the perception of fit
(from too loose to too tight) and thermal (from too cold to too hot) were
different from the other sensory perceptions such as damp (from not at all
to extremely). In their study, Wong et al. [26] developed the neural network
prediction model on the basis of a feed-forward back-propagation network.
The network model consisted of three layers, i.e. input layer, hidden layer
and output layer. A good agreement between predicted and actual clothing
comfort perceptions have been observed, which proved that the wear trial
technique is an effective technique for predicting the psychological
perceptions of clothing sensory comfort.

2.4

Psychological aspects of aesthetic comfort

The physical attributes of the human body is directly related to the aesthetic
comfort characteristics of clothing. A large number of researchers [27–
32] have studied the complex interplay between clothing aesthetics and
body attributes and the human body has been designated as the central
element in the aesthetic experience of clothing. The relationships between
the aesthetics of clothing and the physical attributes of the body is not the
matter of only textile and clothing discipline but many other fields of

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Science in clothing comfort

research, like physical and demographic attributes affecting aesthetics,
social aspect, psychological, cultural aspects that influence the aesthetic
experience, etc. The researchers have taken into account of all these factors
in their studies on clothing aesthetics.
Human body imaging technique may be adopted in the study of clothing
aesthetics. The clothing not only creates a person’s appearance but also
provide aesthetic pleasure to the person through the wearing experience.
The wearers generally try to achieve the aesthetic pleasure through their
clothing by emphasizing certain positive features of their bodies through
their clothing and hiding other negative features. Therefore, aesthetic
attributes in clothing helps to minimize the differences between cultural
beauty concepts and their perceived appearance, which helps to improve
self-image and have stronger self-esteem of a person [33].

2.4.1

Evaluation of clothing aesthetics

Clothing comfort related to aesthetics is a complex interrelationship
between the following concepts:
●
●
●
●
●

Style of the clothing adopted
Surface texture of clothing
Drape of fabric used
Cover
Creasing and resilience characteristics of fabrics.

All these concepts are generally described by how they are subjectively
perceived by common word pairs used to communicate their values (e.g.,
thick–thin, rough–smooth, etc.). The physical or transmission
characteristics of fabrics, namely mass per unit area, thickness, thread
density, air permeability, thermal transmission, wicking, etc., can be easily
measured by objective test methods. But, due to significant subjectivity
the aesthetic characteristics cannot be measured accurately and there is no
standard method of measuring aesthetic characteristics of clothing. The
fabric aesthetics is entirely subjective and different people can rate same
fabric in different scales based on their own perceptions.
The main problem with the measurement of aesthetic attributes of
clothing is to gather useful and consistent information by questioning
people about the clothing or fabric. If this is done properly, then the
numerical data can be obtained using different mathematical techniques
and subjective test methods. The possible steps to measure the fabric
aesthetics are [34] as follows:
●

Definition of fabric aesthetics in terms of basic elements having the
form of common words.

Psychology and comfort
●

●

25

Identification of a system for selecting rating scales. This system
involves questions for subjective measurement of these basic
elements.
Transformation of data from rating scales to numerical definition of
a specific aesthetic property.

By the term ‘aesthetics of clothing’ we generally mean the appearance
and handle of fabrics, which are mainly perceived by the senses. It has
been already mentioned that the perceptions are relative attributes, i.e. it
can be scaled based on their relative position on scales involving contrasts
(warm–cool, good–bad, soft–hard, beautiful–ugly). Clothing aesthetic
perceptions are the combinations and interrelations of measurable physical
data (rigid–flexible, soft–hard) and values, which are psychological factors
(good–bad, beautiful–ugly, fashionable–unfashionable). Some
terminologies associated with the aesthetics of clothing are really
conceptual, for example hand, cover and body do not have value polarity,
i.e. they need not be good or bad, desirable or undesirable. Moreover, all
these terminologies do not have a simple measurable physical reality.
However, sometimes these parameters are defined to represent sense data
only. For example, ‘surface texture’ is a fabric parameter which can be
measured subjectively, but still this is merely a terminology which
represents the skin sensorial as well as visual sensations of fabric. Limiting
the meaning in this way often restricts communicative value. The surface
texture of fabrics is evaluated in relation to the aesthetic comfort
characteristics of clothing. To evaluate is to judge something on a scale
that has opposite poles or a gradation. For example, a scale for evaluating
comfort concepts is the pain–pleasure polar scale. It is a psycho-physical
scale. Aesthetic concepts are not physical attributes. These can be expressed
in terms of psycho–cultural scales and can be evaluated on polar scales
such as beautiful–ugly, good–bad, etc. The surface texture of a specific
type of fabric can be evaluated by the simple polar word scale, like soft–
harsh or rough–smooth. It is quite possible that a fabric is aesthetically
very beautiful, but painful from the skin sensory comfort point of view.
For example, a tweed fabric may be unpleasant to the skin but pleasant to
the eye or an aesthetically beautiful winter garment may be thermophysiologically extremely uncomfortable in warm and humid conditions.
The aesthetic character of fabrics is primarily defined by subjective
methods. The wearers are asked to evaluate qualities identified by simple
word pairs whose meanings can be easily recognized as polar opposite
words, like smooth–rough, soft–hard, flexible–rigid. Some of the confusing
clothing terms should be avoided in evaluating the fabric aesthetics. For
example, for evaluating the drape behaviour of fabric, if one wants to
decide the fact that whether the fabric is good or bad the answer will create

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Science in clothing comfort

confusion. He should know the exact application of fabric, e.g. whether
the fabric will be used for skirts or for window coverings. A fabric drape
may be good for window covering, but the similar drape may not be
acceptable for skirts. So, simpler attributes signified by polar words, like
flexible–stiff, which are related to fabric drape characteristics, need to be
evaluated.

2.4.2

Aesthetic concepts of clothing

Clothing aesthetics can be divided into different aesthetic concepts. Figure
2.2 shows the interrelationships among physical parameters, psychological
attributes, subjective evaluation and aesthetic comfort of clothing.

2.2 Components of clothing aesthetics.

Following are the guidelines for setting aesthetic concepts related to
psychological clothing comfort:
●

●

The concept must be related to at least one of three main physiological
sensations, i.e. visual sensation, tactile sensation, or kinesthetic
sensation.
The concept can be a combination of sub-concepts, expressed by
words which are more explicit. For example, ‘resilience’ is less
explicit than its component sub-concepts ‘compressional resilience’
and ‘liveliness’. Similarly, the term cloth cover cannot communicate
the aesthetic concept completely, so its sub-concepts ‘top cover’ and
‘bottom cover’ are used.

Psychology and comfort
●

●

27

The concepts may be made technically explicit by physical
measurements. These measurements attempt to quantify objectively
to replace the sense data.
Aesthetic, concepts or sub-concepts can always be evaluated
subjectively. Subjective evaluation scales are represented by common
words (quality words) which express the psychological value of the
sense data associated with the concept.

The most commonly used concepts related to clothing aesthetic
attributes are clothing cover, drape, body, style, surface texture and
resilience [34].
Cover

Drape

Body

– The cover can be sub-divided into ‘top cover’ and
‘bottom cover’. The ‘top cover’ is the apparent
continuity of the surface of fabric, i.e. degree of
obscurity of the fabric weave pattern due to surface
fuzziness. On the other hand the ‘bottom cover’ is the
degree of obscurity of the fabric weave pattern due to
fabric sub-layer. The cover can be expressed by dense–
open, fuzzy–clean, smooth–rough, full–lean, etc. The
fabric cover is objectively measured by streak meter,
light transmission, surface contact area, air
permeability, etc.
– The fabric drape is generally sub-divided into
‘liveliness’ and ‘fit’. The term drape means the form
a fabric will assume due to its own weight when hung
freely. The aesthetic perception of fabric drape
depends on the behaviour of fabric under static and
dynamic states. The fabric drape is expressed
clinging–flowing, dead–lively, limp–crisp, sleazy–
full, etc. Drape of fabric mainly depends on the
bending and the shear characteristics and can be
subjectively evaluated by measuring bending rigidity
(cantilever or loop method), drape coefficient by
drape meter.
– The body of a fabric means the overall substance
between the edges of fabric, i.e. the perception of
the total substance of fabric during use. The body of
fabric is expressed by light–heavy, lofty–thin, bulky–
sleazy, full–lean, etc. The fabric body is subjectively
evaluated by measuring mass per unit area, thickness,
porosity, density, etc.

28
Style

Science in clothing comfort

– Style is basically a visual aesthetic perception and
can be perceived through colour, pattern and type of
clothing. Clothing style is evolved from the
combined perceptions of the textile arts and
technology. The style of fabric is subjectively
evaluated by measuring the colour value, depth of
shade, weave structure, yarn structure, clothing
pattern, fit of garment, etc.
Surface texture – The surface texture of fabric means the tactility,
surface roughness and pattern of fabric. This is
basically tactile and visual perceptions of fabrics. It
is generally expressed by the terms smooth–rough,
dry–clammy, grainy–plain, slippery–sticky, slick–
greasy, fuzzy or hairy–clean, soft–hard, pricky–soft,
warm–cool, dull–lustrous, etc. Subjectively the
surface texture can be evaluated by measuring
surface roughness of fabric, fabric–fabric or fabric–
other surface friction both static and dynamic
conditions, optical reflectance of fabric surface,
contact point or contact area at the fabric surface,
surface fuzziness, etc.
Resilience
– It is the ability of a fabric to return to its previous
position after deformation force is released.
Generally resilience can be of different type, i.e.
resilience from wrinkle or crease, compressional
resilience, extensional resilience, liveliness, etc. The
perception of wrinkle or crease resilience is the
ability of fabric to recover from wrinkle or crease.
Similarly, compressional resilience and extensional
resilience are the perceptions of the resistance to and
recovery from transverse compression and planer
extension of the fabric respectively. The liveliness
is the perception of the rate of recovery from small
deformations. The resilience is generally expressed
in terms of bounce–limp, lively–rubbery, lofty–
mushy, snappy–stiff, nervous–dead, etc. The
subjective evaluation of resilience characteristics of
fabric is done by measuring compressional, tensile
or bending characteristics of fabrics (e.g. Kawabata
evaluation system), vibration damping, crease
recovery angle, etc.

Psychology and comfort

29

References
1.
2.
3.
4.
5.
6.

7.
8.
9.
10.
11.
12.
13.
14.
15.

16.
17.
18.
19.

20.

21.

22.

ANDREEN J . H ., GIBSON J . W. and WETMORE O . C ., ‘Fabric evaluations based on
physiological measurements of comfort’, Textile Res. J. 23, 11–22, 1953.
LI Y ., ‘The science of clothing comfort’, Text. Prog. 31(1/2), 2001.
LAMOTTE R . H ., HOLLIES N . R . S . and GOLDMAN R . F ., Clothing Comfort, Ann Arbor
Science, Michigan, 1977, 85–105.
SLATER . K ., The assessment of comfort, J. Text. Inst. 77, 157–171, 1986.
LI, Y ., Clothing, comfort and its application, Text. Asia 279, 29–33, 1998.
WONG A . S . W ., LI Y ., YEUNG P . K . W. and LEE P . W . H ., Neural network predictions
of human psychological perceptions of clothing sensory comfort, Textile Res.
J. 73, 31–37, 2003.
LAMOTTE R . H ., Psychophysical and Neurophysiological Studies of Tactile
Sensibility, in: Clothing Comfort, Ann Arbor Science, Ann Arbor, 1977.
KAWABATA S ., The Standardization and Analysis of Hand Evaluation, 2nd edition,
The Textile Machinery Society of Japan, Osaka, 1980.
ENGEN T ., Psychophysics in Sensory Systems II: Senses Other than Vision, editor
WOLFE J . M ., A Pro Scientia Viva Title, Boston, 1988, 104–106.
LAMING D ., Psychophysics in Sensation and Perception, editors Gregory R. L.
and Colman A. M., Longman, London, 1996, 97–123.
FISKE A . P ., Structures of Social Life: The Four Elementary Forms of Human
Relations. The Free Press, New York, 1991.
STEVENS S . S ., ‘On the theory of scales of measurement’, Science 103, 677–680,
1946.
BOLENDER J ., ‘Hints of beauty in social cognition: Broken symmetries in mental
dynamics’, New Ideas in Psychology, 26, 1–22, 2008.
BOX G . E . P . and BEHNKEN D . W., ‘Some new three level designs for the study of
quantitative variables’, Technometrics 2, 455–476, 1960.
CARDELLO A . V ., WINTERHALTER C . and SCHUTZ H . G ., ‘Predicting the handle and
comfort of military clothing fabrics from sensory and instrumental data:
Development and application of new psychophysical methods’, Textile Res. J.
73, 221–237, 2003.
BURGARD D . R . and KUZNICKI J . T ., Chemometrics: Chemical and Sensory Data,
CRC Press, Boca Raton, 1990.
MEILGAARD M . C ., CIVILLE , G . V . and CARR B . T ., Sensory Evaluation Techniques,
2nd edition, CRC Press, Boca Raton, 1991.
STEVENS S . S . and GALANTER E . H ., ‘Ratio scales and category scales for a dozen
perceptual continua’, J. Exp. Psychol. 54, 377–411, 1957.
GREEN B . G ., DALTON P., COWART B., SHAFFER G ., RANKIN K. and HIGGINS J ., ‘Evaluating
the labeled magnitude scale for measuring sensations of taste and smell’, Chem.
Senses 21(3), 323–335, 1996.
KAWABATA S . and NIWA M ., Analysis of hand evaluation of wool fabrics for men’s
suits using data of a thousand samples and computation of hand from the physical
properties, in Proceedings of 5th International Wool Textile Research Conference
5, 413–424, 1975.
KAWABATA S ., POSTLE R . and NIWA M., Objective Specification of Fabric Quality,
Mechanical Properties and Performance, The Textile Machinery Society of
Japan, Osaka, 1982.
HOLLIES N . R . S ., CUSTER A . G ., MOREN C . J . and HOWARD M . E ., ‘A human perception
analysis approach to clothing comfort’, Textile Res. J. 49, 557–564, 1979.

30
23.

Science in clothing comfort
HOLLIES N . R . S ., DEMARTINO R . N ., YOON H . N ., BUCKLEY A ., BECKER C . L .

and JACKSON
‘Improved comfort polyester, Part IV: Analysis of the four wearer trials’,
Textile Res. J. 54, 544–548, 1984.
YOO S . and BARKER R . L ., ‘Comfort properties of heat resistant protective work
wear in varying conditions of physical activity and environment. Part II:
Perceived comfort response to garments and its relationship to fabric properties’,
Textile Res. J. 75, 531–539, 2005.
HOLLIES N . R . S ., ‘Psychological scaling in comfort assessment’, In Clothing
Comfort, editors Hollies N. R. S. and Goldman R. F.) Ann Arbor Science
Publishers Inc., Michigan, 1977.
WONG A . S . W., LI Y ., YEUNG P . K . W. and LEE P . W. H ., ‘Neural network predictions
of human psychological perceptions of clothing sensory comfort’, Textile Res.
J. 73, 31–37, 2003.
RUDD N . A ., LENNON S . J ., ‘Body image: linking aesthetics and social psychology
of appearance, Clothing and Text. Res. J. 19(3), 120–133, 2001.
DELONG M., The Way We Look: Dress and Aesthetics, Fairchild Publications,
New York, 1998.
HILLESTAD R., ‘The underlying structure of appearance’, Dress 5, 117–125, 1980.
DELONG M. R . and LARNTZ K ., ‘Measuring visual response to clothing’, Home
Economics Res. J. 8(4), 281–293, 1980.
FIORE A . M ., MORENO J . M . and KIMLE P . A ., ‘Aesthetics: A comparison of the state
of the art outside and inside the field of textiles and clothing. Part III:
Appreciation process, appreciator and summary comparisons’, Clothing and
Text. Res. J., 14(3), 169–184, 1996.
KUPFER J ., Clothing and aesthetic experience, editors DELONG M . and FIORE A . M .,
Aesthetics of textiles and clothing: Advancing multi-disciplinary perspective,
Monument, Intl Text. and Apparel Assoc. 97–104, 1994.
CHATTARAMAN V . and RUDD N . A ., ‘Preferences for aesthetic attributes in clothing
as a function of body image, body cathexis and body size’, Clothing and Text.
Res. J. 24, 46–61, 2006.
B R A N D R . H ., ‘Measurement of fabric aesthetics: Analysis of aesthetic
components’, Textile Res. J. 34, 791–801, 1964.
W .,

24.

25.

26.

27.
28.
29.
30.
31.

32.

33.

34.

3
Neurophysiological processes in clothing comfort

3.1

Neurophysiological perceptions

3.1.1

Sensory system of human skin

The structure of human skin is very complex. Figure 3.1 shows the structure
of hairy skin which covers most of the human body. The skin has several
layers. The overlaying outer layer is called epidermis, which consists of
several layers of dead cells on top of a single living cell. The layer below
epidermis is called dermis, which contains a network of blood vessels,
hair follicle, sweat gland and sebaceous gland. Beneath the dermis are
subcutaneous fatty tissues. The layers of epidermis are as follows: Stratum
Germinativum, i.e. growing layer; Malpighion layer, i.e. pigment layer;
Stratum Spinosum, i.e. prickly cell layer; Stratum Granulosum, i.e. granular
layer; Stratum Lucidum and Stratum Corneum, i.e. horny layer [1]. The
basic functions of human skin are [2]
●
●
●
●
●
●
●
●
●
●

To protect from external stimuli like light, heat, cold and radiation;
To check of body fluids and tissues;
Reception of stimuli like pressure, heat, pain, etc.;
Biochemical synthesis;
Metabolism and disposal of biochemical wastes;
Regulation of body temperature;
Controlling of blood pressure;
Prevent penetration of noxious foreign material and radiation;
Cushions against mechanical shock;
Interspecies identification.

Skin is the interface between the body and its environment and it is
highly stimulated and contains specialized sensory receptors to sense
different external stimuli. There are mainly three types of stimuli, i.e.
mechanical interactions with external objects, thermal interactions due to
heat flow to or from the body surface, and damaging (traumatic and
chemical) insults. In responding to these stimuli, the skin sensors generate
different sensations, like touch, pressure, pain, warm, cold, etc.

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Neurophysiological processes in clothing comfort

33

The Pacini’s corpuscle detects rapid vibration (200–300 Hz). Ruffini’s
endings are responsible for detecting tension deep in the skin. The main
functions of Meissner’s corpuscles are to detect and adapt the changes in
texture. Merkle’s nerve endings detect sustained touch and pressure [3,
4]. Hair follcle’s nerve ends and free nerve ends are also mechanoreceptors.
Hair follcle’s nerve ends sense the changes in position of hairs and the
free nerve ends sense touch, pressure and stretch.
The thermoreceptors are the sensory receptors which code the absolute
and the relative changes in temperature, primarily within the safe
temperature range and also respond to both constant and fluctuating skin
temperatures. There are two types of thermoreceptors: cold receptors and
warm receptors. The cold receptors have a peak sensitivity of around 25–
30°C and are excited by reduction in temperature. The warm receptors
have a peak sensitivity of around 39–40°C and are sensitive to increase in
skin temperature [4, 5].
The nociceptors are the sensory receptors which are responsible for
sensing the pain, like heating the skin, strong pressure, or contact with
sharp or damaging objects. These receptors have relatively high thresholds
to act as warning devices that enable the organism to take protective action
in time [5]. They react to potentially damaging stimuli by sending nerve
signals to the spinal cord and brain.

3.1.2

Nerve endings in human skin

The sensory perceptions of human skin are governed by mainly two types
of nerve endings in the skin layers, i.e. corpuscular endings and free nerve
endings. Figure 3.3 illustrates the different types of nerve endings and
nerve fibres in the skin layers. Corpuscular endings have small swelling
on the nerve fibres and are responsible for different type of sensations,
like touch, pressure, cold, heat, etc. The different types of nerve endings
are Pacini’s corpuscles, Meissner corpuscles, Merkle’s nerve ending,
Krause’s end bulb, Ruffini endings, hair follicle nerve ends and free nerve
ends. The free nerve endings in subcutaneous fat are associated with pain
fibre, and those projecting in to the epidermis may be associated with cold
fibres or pain fibres [6].
Pacini’s corpuscles
These mechanoreceptor nerve endings are responsible for pain and pressure
sensations and detect gross pressure changes and vibrations. These are
rapidly adapting receptors in the human skin. Due to any deformation in
the corpuscles the pressure sensitive sodium ion channels are opened, which
allow the sodium ions inflow and create a receptor potential. Pacini’s

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Pacini’s corpuscles

Ruffinl’s endings

Meissner corpuscles

Merkle’s nerve ending

Hair follicle nerve ends

Krause’s end buld

Free nerve ends

3.3 Different nerve endings in the skin layers.

corpuscles are capable to vibration and can sense any vibration even from
few centimeters. Their optimal sensitivity is 250 Hz and this is the
frequency range generated at the finger tips by textures of size less than
200 μms [7]. These nerve endings respond when the skin is rapidly
indented, but do not respond when the pressure is steady [8].
Meissner’s or tactile corpuscles
These mechanoreceptor nerve endings are responsible for light touch.
These rapidly adaptive receptors have highest sensitivity (lowest threshold)
when sensing vibration of lower frequency. The tactile corpuscles are
distributed throughout the skin, but the concentration is very high to those
places where the sensitivity is high at light touch, e.g. palms, lips, face,
tongue, fingertips, etc. In case of any deformation, the Meissner’s
corpuscles cause an action potential in the nerve. As these are quickly
adapting mechanoreceptors, the action potential generated in the nerves
decreases rapidly and ultimately ceases. Due to this action the wearer stops
feeling his clothing after certain time. Due to their superficial location in
the dermis these mechanoreceptors are particularly sensitive to touch and
vibrations, but they cannot detect properly because they can only sense
that something is touching the skin [9].

Neurophysiological processes in clothing comfort

35

Merkel nerve endings
These mechanoreceptor nerve endings are responsible for providing
information regarding pressure and texture and are classified as slowly
adaptive type of mechanoreceptors. These nerve endings also have wide
distribution in the human skin. These nerve endings are structurally rigid
and are not encapsulated, which causes them to have a sustained response
to mechanical deflection of the tissue of less than 1μm. Due to the sustained
response to pressure these nerve endings are classified as slowly adapting.
Merkel nerve ending is the most sensitive mechanoreceptor to vibrate at
low frequency (within 5–15 Hz) [7].
Krause’s end bulbs
The Krause’s end bulbs are the mechanoreceptors in the human skin and
have the ability to detect low-frequency vibration. These can be found in
some specific parts of human body, e.g. in the transparent lubricating
mucous membrane that covers the eyeball and the area under the surface
of the eyelid (conjunctiva), in the mucous membrane of the lips and tongue,
etc.
Ruffini endings
This is a class of slowly adapting spindle-shaped mechanoreceptor and
can be found only in the glabrous dermis and subcutaneous tissue of humans
[10]. It is sensitive to skin stretch and contributes to the kinesthetic sense,
e.g. control of finger position and movement. These mechanoreceptors
sense and monitor the slipping of objects along the surface of the skin,
e.g. slipping of garment on one’s body. These are located in the deep layers
of the skin and register mechanical deformation within joints more
specifically very small angle change (up to 2 degree) at continuous pressure
state [11].
Hair follicle nerve ends
These are the mechanoreceptors in the human skin present at the base of
the hair follicle. These are sensory nerve fibres that wrap around each hair
bulb. During bending or pulling of the hair these stimulate the nerve
endings allowing a person to feel that the hair has been moved or pulled.
One of the main functions of hair is to act as a sensitive touch receptor
and it is done through this receptor. Greasy or oily glands are also associated
with each hair follicle and these glands produce an oily secretion to help
condition the hair and surrounding skin.

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Free nerve endings
The free nerve endings are the most common type of nerve ending and are
most frequently found in the skin. These nerve endings are responsible
for conveying sensory information from the periphery of body to the brain.
The free nerve endings act as skin sensory receptors and are mainly used
to detect pain sensations. Unlike those found in Meissner’s or Pacini’s
corpuscles, the free nerve endings are un-capsulated and have no complex
sensory structures. They penetrate the epidermis and end in the stratum
granulosum [12] and can have different rate of adaptation, i.e. rapidly
adapting, intermediate adapting and slowly adapting. Different free nerve
endings work as thermoreceptors, mechanoreceptors and nociceptors. In
other words, they express polymodality, i.e. having multiple stimulus
modalities. They are responsible for sensing mechanical stimuli (e.g., touch,
pressure, prick, stretch, etc.), temperature, or pain.

3.2

Mechanical and thermal receptors

Various sensory receptors are responded by mechanical and thermal stimuli
generated by surroundings, results in different perceptions, like touch,
pressure, tactile, warm, cold, humid, prickle, itch, etc., which affect the
comfort sensations of wearer.

3.2.1

Sensations related to mechanical stimuli

The mechanical sensory perceptions of clothing are mainly of four types,
namely wear sensations during activity; prickle, itch and rashes; touch
and pressure sensations; and roughness and scratchiness sensation [5].
Wear sensations during activity
Clothing is continuously in contact with the skin of most part of the
human body and this contact may be dynamic as well as static. During
activity or movement of a clothed person the dynamic wear sensation
changes rapidly depending on the situations. When a person moves, the
cloth touches different parts of the body which results different dynamic
sensations as the area of contact is large and spreads over parts with
different sensitivity. Due to the change in activity level the human body
frequently changes its physiological parameters such as rate of sweating,
temperature of skin and moisture at the skin surface, which generates
various new thermal stimuli. Depending on the interactive phenomenon
of clothing with the skin in terms of heat and moisture the mechanical
stimuli also changes. Clothing also moves towards and away from the

Neurophysiological processes in clothing comfort

37

skin frequently due to the body movement, which also induces new
mechanical stimuli frequently.
Prickle, itch and rashes
One of the very common types of discomfort sensations related to
mechanical stimuli is prickle. The wearers always complain about the
prickle for those clothing which are used next to skin. For example, a
person feels prickle sensation when he wears a woollen inner garment,
especially with coarser wool in hot and humid condition. Prickle is usually
described as the sensation of many gentle pinpricks. It’s a common
perception that the prickle sensation associated with wool is related with
skin allergic response. The degree of discomfort caused by prickle varies
with person, skin type, humidity and temperature of atmosphere as well as
in the microclimate, type of fibre used in clothing, etc. The relationship
between prickle and itch sensation and human cutaneous small nerves have
been studied [13], where skin sensations were tested on the forearms of
different volunteers, in whom anoxia nerves blocks of the forearms were
produced by inflating a blood pressure cuff (about 270 mm Hg) on the
upper forearm, as shown in Fig. 3.4.

Pressure exerted by
blood pressure cuff

Sensation
detection point

3.4 Prickle and itch sensation test setup [5].

The above study [13] reported that both touch and prickle sensations
change with time (Fig. 3.5) and the prickle sensations are associated with
small nerve fibres. It is observed from Fig. 3.5 that touch sensation dropped
consistently, initially at slower rate and then at very fast rate. On the other
hand the prickle sensation, evoked by pain, temperature and fabric, initially
increases and then drops rapidly. The touch sensation is completely lost
after about 20 min, but prickle sensation remained until about 40 min and
the point of complete anesthesia starts [5, 13].

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3.5 Time course of loss of prickle, and touch sensations [5].

A number of studies [14, 15] have been carried out to understand the
prickle characteristics of fabrics. Wills [14] reported that for the initiation
of pain sensation the summation of responses from the pain group of nerves
is necessary. Gransworthy et al. [15] carried out extensive study to
understand the causes of prickle and itch from the skin contact of fabrics.
They conclude from their results that fabric-evoked prickle is the result of
low-grade activity in nociceptors and that the stimuli are protruding fibre
ends exerting loads of approximately 75 mgf or more against the skin.
They have also observed that to have prickle sensation a minimum number
of high-load bearing fibre ends or certain minimum skin contact area with
fabric is required. Prickles from the fabrics could not be perceived if the
density of high load bearing fibre ends is less than 3 per 10 cm2 of the
fabric, or the skin contact area is below 5 cm2 [5, 15]. The fabric prickle
sensation depends mainly on the following important parameters [5]:
●

●

●

Males have higher thresholds and more variations to sensitivity to
prickles than females. This means that female skin is more sensitive
towards prickle sensation, which is due to differences in features of
skin sensory nerves among male and female.
With the increase of age of a person the hardness of his outermost
skin layer increases, thus the prickle sensitivity decreases gradually
with age. Due to the difference in skin hardness a kid may feel more
prickle sensation than an old person with a particular type fabric
touching the skin.
The free nerve endings, which sense pain (nociceptors), are generally
located very close to surface of hairy skin, but not in glabrous skin.
On the human body, glabrous skin is skin that is hairless. It is found

Neurophysiological processes in clothing comfort

●

39

on fingers, palm of the hand or the sole of the foot. Due to absence
of nociceptors close to the skin surface the prickle sensation due to
fabric is not felt with figures, palms or feet.
It has been observed that in hot and humid environment a person
feels more prickle sensation. The outermost layer of the epidermis
consists of dead cells, which is known as stratum corneum. The
stratum corneum becomes soft in humid condition and the protruding
fibres from garments can easily penetrate through it, which results
prickle sensation. It has also been reported [15] that for constant
humidity the prickle sensitivity increased with the increase in ambient
temperature in the range of 12–32°C. This is due to increase in the
skin moisture content due to perspiration in hot and humid conditions,
which result in the increase in softness of stratum corneum.

In the classical definition, ‘Itching is an unpleasant cutaneous sensation
which provoke desire to scratch’ [16]. Itch sensation can originate in the
peripheral nervous system or in the central nervous system [17] and the
itch receptors are only found on the top two skin layers, the epidermis and
the epidermal/dermal transition layers. Itch originating in the skin can be
induced by a variety of stimuli, including mechanical, chemical, thermal
and electrical stimulation. Normally the itch sensation develops the
activation of some superficial skin pain receptors. The pain receptors
responsible for itch may be of a different type to those responsible for
prickle sensation. The sensations of itch and pain are generally considered
to be dependent of each other, but in a recent study [18] it was found that
itch has several features in common with pain, but exhibits notable
differences.
The prickle and itch can be a major detrimental factor of whether a
person can wear the garment made of wool, acrylic or some other fibres
comfortably. The skin irritation on wearing wool garment directly on the
skin has long been thought to be due to the result of an allergy to the wool
itself. But, researches in this area revealed that very few people have a
true allergy to wool, and that it’s the mechanics of the fibre itself that
irritate the skin. People with sensitizing skin conditions, such as eczema
or atopic dermatitis, who are already more susceptible to discomfort from
wearing clothing against their skin made with these materials. The pain
receptors in the skin are mainly responsible for the prickle sensation during
wearing of garments made of wool and other fibres. Prickle and itch
sensations, on contact with natural and synthetic fibres, vary from person
to person, and for some sensitive person the skin can even redden from
the constant touch with these fibres. The itch and prickle sensation can
also depend on individual factors, like skin thickness, age, temperature
and moisture on the skin. The thinner skin is more sensitive. Younger

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persons have thinner skin than an old person, so generally the skin
sensitivity towards itching and prickle is more for younger person. The
itch sensation increases with temperature of the atmosphere and humidity
of the skin. Apart from the type of fibre, the physical characteristics fibres,
such as length and diameter, play role in causing skin discomfort. For
example, shorter fibres generates the perception of prickle, as there are
more fibre ends to be felt in any given surface area of a garment. Similarly,
coarser fibres are likely to intensify the prickling sensation than their finer
counterparts due to higher bending rigidity. So, a person can try to prevent
or reduce the prickle and itch sensations in their garments by proper
selection of materials.
Skin rashes or localized skin reddening or localized skin irritation occurs
in the small proportion of the skin. There are different causes of skin rashes,
and the garments with prickle and itch sensations are one of the causes of
generation of skin rashes. The mechanical stimulation of skin pain receptors
from prickly fabrics are the main causes of garment related skin rashes.
The probable mechanism of skin rashes due to prickle and itch is known
is axon reflex [19, 20], which is a response brought on by peripheral nerve
stimulation. Rashes due to clothing may occur very rapidly within minutes
or very slowly in hours and can be relieved quickly after fabric is removed
from the skin. But, in case the garment is in contact with skin for very
long time it may result a severe reaction.
Touch and pressure sensations
Human body can evoke the sensation of touch and pressure at any point
on the surface, but the sensitivity varies from one region of body to another.
In the process of fabric–skin contact and mechanical interaction during
wear, clothing exerts pressure and dynamic mechanical stimulation to the
skin which in turn triggers various mechanoreceptors and generates a wide
range of touch and pressure sensations.
The mechanoreceptors, responsible for touch and pressure sensations,
are sensitive to stimuli that distort their cell membranes. The receptors,
responsible for touch and pressure sensations, contain mechanically
regulated ion channels, which open and close in response to mechanical
actions on the skin surface. The receptors responsible for touch and pressure
sensations are mainly tactile receptors (i.e., free nerve endings, root hair
plexus, Merkel’s discs, Meissner’s corpuscles, Pacinian corpuscles and
Ruffini corpusles) and baroreceptors. The tactile receptors provide the
sensations of touch, pressure and vibration. Distinctions between all these
sensations are not very well defined. Fine touch and pressure receptors
are extremely sensitive and have relatively narrow receptive fields and
provide detailed information about a source of stimulation, including the

Neurophysiological processes in clothing comfort

41

exact location, shape, size, texture and movement. On the other hand, the
receptors for rough touch and pressure provide poor localization and
information. The baroreceptors monitor changes in pressure exerted on
the body by clothing due to movement of a clothed person. The
baroreceptors consist of free nerve endings that branch within the elastic
tissues in the walls of organs. During activity the clothing exert different
levels of pressure on the skin which stretch or recoil tissues in the walls,
and the information is then passed on to centres in the brain.
Roughness and scratchiness sensations
Roughness and scratchiness sensations depend on the surface texture of
fabrics and the way the fabrics move over the human skin surface. During
activity of a clothed person, the fabric moves across the underlying skin
and the fabric to skin friction (both static and kinetic friction) resisting
that movement forces the skin to displace. This displacement of skin
stimulates the sensory receptors that are responsible for touch sensation.
As the surface roughness of fabrics increases, this displacement of skin
also become more and the sensory receptors detect this difference in
sensation. Higher fabric to skin friction results more skin abrasion [5, 21].

3.2.2

Sensations related to thermal stimuli

The skin acts as a barrier between the organism and its environment. For
effective designing of comfortable clothing, it is essential to understand
the human thermal physiology, heat and moisture transfer from the skin
surface, and human thermal comfort. Humans maintain their core
temperatures within a small range, between 36 and 38°C. Skin is the most
important organ of human body through which heat and moisture flow to
and from the surrounding environment to maintain the heat balance. The
skin also contains thermal sensors that take part in the thermoregulatory
control, and these affect the person’s thermal sensation and comfort [22].
The complex vascular systems and sweat glands in the skin help to change
the conductance of skin in response to thermoregulatory demands of the
body. Many researchers have established that when the skin is touched
with small warmth and cold stimulators, some spots on the skin feel warm
and/or cold, others do not. The human skin contains four types of thermally
sensitive nerve endings (thermoreceptors), namely cold, warmth, hot pain
and cold pain [23, 24] and each thermoreceptor is activated in a specific
temperature range (Fig. 3.6).

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3.6 Discharge frequencies of a cold receptor, a warmth receptor, and
cold and hot pain receptors at different temperatures [22].

All these nerve endings sense the temperature of skin and transmit the
information to the brain. Cold and warmth receptors in the human skin are
responsible for sensing normal environmental temperatures which are not
harmful to human body. The harmful temperatures (i.e. too hot or too cold),
which are likely to damage an organism are sensed by sub-categories of
nociceptors (i.e. cold pain and hot pain receptors) that may respond to
extreme cold or heat [25].
It can be observed from Fig. 3.6 that the warmth receptors start sensing
at the temperature around 30°C and become inactive at around 50°C with
highest impulse frequency at around 45°C. Normally the hot pain receptors
are active at temperature beyond 50°C and at that time the warmth receptors
are inactive. Similarly, the cold receptors are active within the temperature
range from 7°C to 42°C with highest impulse frequency at around 25°C.
Normally the cold pain receptors are active at temperature below 10°C
and at that time the cold receptors are inactive.
The warmth and cold receptors in the human skin are distributed in
different concentrations in the different parts of the body. In general the
numbers of warmth thermoreceptors are much less than the cold receptors.
Figure 3.7 shows the distribution of the cold and warm receptors in the
different parts of the human skin [22, 26–28].
The cold thermoreceptors are located at upper layer of dermis, i.e.
immediately beneath the epidermis, at an average depth of 0.15–0.17 mm,
whereas the warmth thermoreceptors are located in the dermis and below
cold thermoreceptors. The location of the warmth thermoreceptors is within
the upper layer of the dermis at an average depth of 0.3–0.6 mm [26, 29,
30]. Due to the presence of higher numbers and shallower depth of cold
thermoreceptors as compared to that of warmth thermoreceptors, the

Neurophysiological processes in clothing comfort

43

3.7 Typical number of cold and warm thermoreceptors in human skin.

humans are more sensitive to danger from cold than from heat [22]. The
thermoreceptors are in general dynamic in nature which helps in adaptation
with different climatic conditions and determine the thermal sensation and
comfort responses of a person. Figures 3.8 and 3.9 show the static and
dynamic responses respectively of thermoreceptors (warmth and cold),
i.e. in constant temperature condition and under the abruptly changing
temperature conditions.

3.8 Responses of thermoreceptors under constant temperature [22].

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Science in clothing comfort

3.9 Responses of thermoreceptors under changing temperature [22].

The static temperature responses of cold and warmth thermoreceptors
have been discussed earlier also. It is observed from Fig. 3.8, the
sensitivity of cold thermoreceptor gradually increases with the increase
in temperature and after certain point it starts reducing. Figure 3.9(a)
shows the dynamic changes in temperature profile with time, where
initially for some time the temperature remains at lower level. After
certain time the temperature is increased abruptly to a high level and
then kept at high level for some time. After then the temperature is again
dropped abruptly to a lower level and kept at that level for remaining
time. The thermoreceptors are capable to adapt the changing temperature
conditions and react accordingly. Figure 3.9(b) shows that in case of an
abrupt increase in temperature, the cold thermoreceptors are strongly
stimulated at first, sending impulses at a high frequency, but this
stimulation fades rapidly during the first minute following the increase
in temperature, and then progressively more slowly until it reaches a
steady level. On the other hand, in the case of warmth thermoreceptors
(Figure 3.9c) the impulse frequency increases abruptly with the sudden
drop in temperature and again this stimulation fades rapidly during the
first minute following the drop in temperature. The thermoreceptors
respond to steady temperature states at this lower rate. We generally feel
much colder or warmer when the temperature of the skin changes abruptly

Neurophysiological processes in clothing comfort

45

than when the temperature remains at the same level. For example, the
stronger sensation of cool or warmth felt upon entering a cold pool or a
hot tub [22]. The temperature of skin plays an important role for any
thermal sensation and a person feels comfortable within a narrow range
of skin temperatures. Figure 3.10 shows that different body parts have
different ranges of comfortable temperatures.

3.10 Ranges of comfortable skin temperature by body part [22].

3.2.3

Sensations related to humidity stimuli

There are different types of receptors in the human skin, which sense
different types of physical stimuli including touch, pressure, thermal, cold
and pain. However, there is no receptor in the skin that responds for
moisture or dampness sensation [31].

3.3

Sensory perceptions of human body

Mechanoreceptors are responsible for conveying stimuli of touch or
pressure from skin to the dermal and subdermal receptor sites at which
they are transduced into neural signals, and through the tactile receptors
that perform the transduction. The sensory perception of human skin is
commonly measured by the two-point threshold method. This is the
minimum distance between two point-like indentations applied to the skin
below which only a single point of contact is detected with the senses
(Fig. 3.11).

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3.11 Measurement of sensory perception by
two-point threshold method.

The pressure applied below the two-point threshold distance feels like
one point, and beyond that one can feel distinct differences in pressure.
This value varies from 2.5 mm in the fingers, up to as much as 50 mm for
other body regions [37] as shown in Fig. 3.12 and Table 3.1 [32].

3.12 Mean two-point threshold distance (mm) at different body parts [32].

The two-point threshold for any part of the body is determined by the
size of the receptive fields and the extent of overlap. Tactile sensation
varies widely from person to person and depends very much on the nature
of the stimulus that is used and properties of the stimulus, such as frequency,
duration and amplitude [33, 34]. The two-point tactile sensations change
with the frequencies and amplitude of vibration [35]. In addition to twotype of stimulation can be measured by the minimum noticeable intensity
point threshold distance, the psychophysical thresholds for a particular

Neurophysiological processes in clothing comfort

47

Table 3.1 Mean two-point threshold distance at various body
parts [32]
Body parts

Mean threshold
distance (mm)

Little finger
Ring finger
Middle finger
Index finger
Thumb
Palm
Forearm
Upper arm
Shoulder
Forehead
Cheek
Nose
Upper lip
Breast
Back
Belly
Thigh
Calf
Sole
Hallux

4
2.5
2.5
2.5
3
10
38
43
36
17
7
7
5
32
40
35
45
50
21
9

of stimulation (Imin). It is the minimum amplitude of vibration of stimulation,
keeping other stimulus properties constant, when a person starts sensing
it. On the other hand, the maximum stimulus intensity (Imax) is typically
taken to be the threshold amplitude for pain perception. The maximum
dynamic range R (decibels), attainable by stimulation with a particular
stimulus type, is expressed as [32]
R (dB) = 10 log10 (Imax/Imin)

(3.1)

The maximum dynamic range (R) depends on the type of stimulus,
frequency of stimulation, location on the body, etc. There are different types
of qualitative tactile and vibrotactile sensations in our daily activities. The
tactile sensations include pressure, texture, prick, puncture, thermal properties,
softness, wetness, slip, adhesion, friction, dynamic contact and release), pain,
object features (shape, edges, embossing), etc. Some of the vibrotactile
sensations are tickling, itch, vibration, and buzzing sound [38]. Most of these
sensations are linked with different tactile stimulations of a person.

3.3.1

Transmission of neurophysiological sensations

It is important to identify the specific actuators required to produce the
different types of human neurophysiological sensations with different

48

Science in clothing comfort

tactile displays, like pressure, touch, prickle, etc. Basically the different
types of tactile displays transmit energy to the skin surface and then from
skin to different tactile receptors in the skin. There are different methods
of flow of tactile responses, namely (i) low frequency and low amplitude
mechanical deformation; (ii) vibrotactile stimulation; (iii) electrotactile
stimulation; (iv) force feedback displays; (v) thermal sensation; (vi) air or
liquid jets or currents [32].
The low frequency and low amplitude mechanical deformation is
responsible for sensing contact of any object with our skin, which may be
continuous or intermittent. By this method human is able to distinguish
between continuous contact with an object, and the intermittent contact,
in which an object is brought in and out of contact with the body part. The
human skin has high sensitivity to the intermittent contact [39].
The vibrotactile stimulation senses the matters when they are vibrating
against the skin, and can sense a frequency of about 250 Hz [32]. Vibrations
may be effectively transmitted through an air gap, again due to the high
intermittent contact sensitivity.
In the electrotactile stimulation, currents are passed through the skin,
which excite the sensory systems directly rather than the tactile receptors
themselves. Current may be supplied by electrodes of different types, or
by fine wires inserted into the skin. Different nerves can be excited
differently through the design of the drive signal and electrical contacts.
The force feedback displays are the kinesthetic tactile sensory systems
and they interact with the different types of sensations, like friction,
vibration, etc. The thermal sensations are related to inward or outward
heat flow through skin by conduction via a medium, convection, or
radiation. Heat is transferred to heat-sensitive receptors by conduction
through tissues [32].
The air or liquid in the form of jets or currents stimulate either hair
follicle receptors by moving hairs or by different types of mechanoreceptors
by exciting with forces or vibrating skin [40].

3.4

Physiological requirements of the human body

3.4.1

Metabolic heat and body temperature

In unusual cases, if the core body temperatures drop below 32°C or raise
above 43°C there is a definite risk of life, but for normal activity of the
body still a narrow range, i.e. between 36°C and 38°C is required [41].
Human skin acts as the barrier between the internal body organs and the
external environment and it has important functions in keeping the body
temperature nearly constant. This is done mainly by controlling thermal
radiation, by adjusting the diameter of peripheral blood vessels and by

Neurophysiological processes in clothing comfort

49

sweating. The distribution of skin temperature throughout the body is not
uniform (i.e. lower in the extremities than in the trunk) and it also changes
with environmental temperature (i.e. it is higher in summer than in winter).
The disturbance in stability of body temperature due to heat (in summer)
or cold (in winter) is controlled by internal physiological mechanisms of
body. In winter the reduced temperature is controlled by increased
metabolic rate and constriction of the peripheral blood vessels, whereas
in summer the sweating process is activated to reduce the body temperature
[42].
The blood circulation through the vascular system in the skin (Fig. 3.13)
assists to the principal mechanism of thermal equilibrium. In winter, the
heat is retained within the body by reducing blood circulation
(vasoconstriction) to the skin. In case the vasoconstriction is insufficient
in restricting the body heat, the body starts producing additional metabolic
heat through tensioning the muscles, starting with ‘muscle tone’ in the
skin, and then leading to shivering which begins in trunk region and
transmitted to the limbs [43]. A person stops shivering when he wears
cloth, which is due to the insulation provided by the clothing. On the other
hand, in case of increased body heat, the vascular system in the skin
enhances the release of body heat through the skin (vasodilatation). The
physiological mechanisms are incapable to completely control the body
temperature in a cold climate. So, additional clothing or external heating
are required for maintaining the body temperature.

3.13 Vascular system in the skin [1, 22].

The human body requires about 40 kcal/h/m 2 body area for basic
activities. The heat production rate increases rapidly during heavy activity
and the produced heat has to be dissipated effectively. Figure 3.14 shows
the changes in body core temperature with time at different levels of
activity.

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Science in clothing comfort

3.14 Changes in body core temperature with time at different levels of activities [44].

It can be observed from Fig. 3.14 that during rest the body core
temperature remains almost constant, i.e. approximately around 37°C. In
case when a person is walking the body temperature initially increases
and after that in remains constant. But, in case of heavy activity the body
temperature increases very rapidly. The heat balancing is done by the
exchange of heat with the environment mainly by radiation and to some
extent by conduction [44]. Depending on the extent and direction of the
temperature gradient between the body and the surrounding object or
environment, a person may either gain or lose heat by radiation. The heat
exchange between the human body and the surrounding object or
environment by conduction is through a surrounding medium in contact
with the skin. Due to the lower thermal conductivity of air and most of the
clothing materials, the conductive heat flow is usually of rather small
quantitative importance. On the other hand, the thermal conductivity of
the liquid medium (e.g. water) is very high. Due to this the insulation
characteristics is almost lost when the garment becomes wet.

3.4.2

Metabolic heat loss and sweating

The release of excess metabolic heat happens through the secretion of
sweat through sweat glands onto the surface of skin. The sweating rate of
a person can go up to maximum of 4 l/h [45]. The cooling of human body,
in hot environment, is achieved not by sweating but by the evaporation of
sweat. In very hot and humid condition, although we sweat heavily, but
we normally do not feel cool. This is due to the fact that the sweat cannot
evaporate and take latent heat from our body at high humidity condition
and it simply drips of the body. In dry climate the sweat generally gets

Neurophysiological processes in clothing comfort

51

evaporated, without wetting the skin surface, by the heat supplied by the
skin surface (insensible evaporation). No cooling effect is achieved and
the body temperature rises steeply. In case there is little wind blowing,
that helps in evaporation of sweat even in hot and humid climate. The
evaporative cooling in a given climatic condition depends on the fact that
whether a person gets used to that climate, which is known as
acclimatization. The higher temperature of the surrounding environment
does not ensure that the sweat will always evaporate. The sweat may start
dripping for a person who is not used to the hot climate and the body heat
transmission through evaporation becomes ineffective. On the other hand,
if the same person gets used to the same hot climate he will look drier and
feel cooler due to evaporative cooling.
The rate of sweating depends on the number of participating sweat
glands and the output of each active gland. The evaporative heat loss
becomes more effective if the sweat, coming out from the active sweat
glands, covers the body evenly. The number of sweat glands per unit area
is different at different parts of the body, e.g. very high concentration is in
the front and back of trunk, back of hand, forearm, upper arm, forehead;
medium concentration in arms, legs, cheeks; and very low concentration
in soles, palms, armpits, inside of thighs [22, 46]. The distribution of
number active sweat glands/cm2 in some of the human body segments is
shown in Fig. 3.15 [47].

3.15 Distribution of sweat gland (glands/cm2) in human body [32].

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References
1.

SHARMA S .,

Topical Drug Delivery Systems: A Review, Pharmainfo.net, 2008,

6(5).
2.
3.
4.
5.
6.
7.
8.

9.
10.
11.
12.
13.

14.
15.

16.
17.
18.

19.
20.
21.
22.
23.

MITHAL B . M. and SAHA R . N ., A Hand Book of Cosmetics, 1st edition, Vallabh
Prakashan, Delhi, 2003.
MCNULTY and MACEFIELD , J. Physiol. 537, 1021–1032, 2001.
IGGO A., Sensory Receptors, Cutaneous in Sensory Systems II: Senses other than
Vision, editor WOLFE J. M .), A Pro Scientia Viva Title, Boston, 1988.
LI Y ., ‘The science of clothing comfort’, Text. Prog. 31(1/2), 2001.
CORE S . and WARD L . M ., Sensation and Perception, Harcort Brace Jovanovich,
New York, 1989.
KANDEL E . R ., SCHWARTZ J . H ., JESSELL T . M ., editors, Principles of Neural Science,
McGraw-Hill, Health Professions Division, New York, 2000.
SCHEIBERT J ., LEURENT S ., PREVOST A . and DEBRÉGEAS G ., ‘The role of fingerprints
in the coding of tactile information probed with a biomimetic sensor’, Science
323(5920), 1503–1506, 2009.
DONALD L . and RUBBELKE D . A . Tissues of the Human Body: An Introduction,
McGraw-Hill, New York, 1999.
MOUNTCASTLE V . B ., The Sensory Hand: Neural Mechanisms of Somatic Sensation,
Harvard University Press, Cambridge, 2005.
HAMILTON N., Kinesiology: Scientific Basis of Human Motion, McGraw-Hill, New
York, 2008.
MARKS J . G . and MILLER J . J ., Lookingbill and Marks’ Principles of Dermatology,
4th edition, Elsevier Inc., New York, 2006.
WESTERMAN , GARNSWORTHY R . K ., WALKER A ., KENINS P ., GULLY R . L . and FERGIN P .,
Aspects of human cutaneous small nerve function: sensations of prickle and
itch, in Proceedings of the 29th IUPS Satellite Symposium, Budapest, Hungary,
1984.
WILLIS W. D ., The Pain System: The Neural Basis of Nociceptive Transmission
in the Mammalian Nervous System, Karger, Basel, Switzerland, 8, 1985.
GARNSWORTHY R . K ., GULLY R . L ., KENINS P ., MAYFIELD R . J . and WESTERMAN R . A .,
‘Identification of the physical stimulus and the neural basis of fabric-evoked
prickle’, J. Neurophysiol. 59, 1083–1097, 1988.
ROTHMAN S ., ‘Physiology of itching’, Physiol. Rev. 21, 357–381, 1941.
YOSIPOVITCH G ., GREAVES M . W., SCHMELZ M ., ‘Itch’, Lancet 361, 690–694, 2003.
TWYCROSS R ., GREAVES M . W ., HANDWERKER H ., JONES E . A ., LIBRETTO S . E .,
SZEPIETOWSKI J . C . and ZYLICZ Z ., Itch: scratching more than the surface, Q J Med
96(1), 7–26, 2003.
LEMBECK F . and GAMSE R ., Substance P in peripheral sensory processes, Presented
at Ciba Foundation Symposium 91, London, UK, 1982.
LEMBECK F ., Sir Thomas Lewis’s Nocicensor System, Listamine and substance P
containing Primary Afferent Nerves, TINS, 106–108, 1983.
LI Y . and DAI X . O ., editors, Biomechanical Engineering of Textiles and Clothing,
Woodhead Publishing Limited, Cambridge, 2006.
ARENS E . A . and ZHANG H., Thermal and Moisture Transport in Fibrous Materials,
editors PAN N. and GIBSON P., Woodhead Publishing Limited, Cambridge, 2006.
GUYTON A . C . and HALL J . E ., Textbook of Medical Physiology, W.B. Saunders
Company, New York, 2000.

Neurophysiological processes in clothing comfort

25.
26.
27.
28.

29.
30.
31.

32.
33.
34.

35.

36.
37.
38.
39.

40.
41.
42.
43.

44.
45.
46.
47.

53

24.CRAIG A. D., ‘Pain mechanism: Labeled lines versus convergence in central
processing’, Annual Review of Neuroscience 26, 1–30, 2003.
STEVENS J . C . and GREEN B . G ., ‘Temperature-touch interaction: Weber ’s
phenomenon revisited’, Sensory Processes 2, 206–219, 1978.
HENSEL H ., Thermoreception and Temperature Regulation, Academic Press,
London, 1982.
STRUGHOLD H . and PORZ R ., ‘Die Dichte der Kaltpunkte auf der Haut des
menschlichen Korpers’, Zeitschrift fur Biologie 91, 563–571, 1931.
REIN F . H ., Uber die Topographie der Warmempfindung, Beziehungen zwischen
Innervation und receptorischen Endorganen, Zeitschrift fur Biologie 82, 515–
535, 1925.
BAZETT C . and MCGLONE B ., ‘Experiments on the mechanism of stimulation of
endorgans for cold’, American J. Physiol. 93, 632, 1930.
BAZETT C., MCGLONE B. and BROCKLEHUJRST R. J . ‘The temperature in the tissue which
accompanies temperature sensations’, J. Physiol., London 69, 88–112, 1930.
WONG A . S . W ., LI Y . and NEWTON E ., Mathematical simulation of human
psychological perception of moisture sensation, Studies in Computational
Intelligence, Springer, Berlin/Heidelberg, 2007, p. 55.
YON V ., Tactile sensory substitution: models for enaction in HCI, Interacting
with Computers, 2008.
CRAIG J . C. and JOHNSON K. O ., The two-point threshold: not a measure of tactile
spatial resolution, Current Directions in Psychological Science 9(1), 29–32, 2000.
CHOLEWIAK R . W. and COLLINS A . A ., The generation of vibrotactile patterns on a
linear array: influences of body site, time, and presentation mode, Perception
and Psychophysics 62(6), 1220–1235, 2000.
HAYASHI K . and NINJOUJI T ., Two-point discrimination threshold as a function of
frequency and polarity at fingertip by electrical stimulation, in Proceedings of
the 26th Annual International Conference of the IEEE EMBS, 2004.
JONES L . A . and SARTER N . B ., Tactile displays: guidance for their design and
application. Human Factors 50(1), 90–111, 2008.
KANDEL E . R ., SCHWARTZ J . H . and JESSELL T . M., Principles of Neural Science, 4th
edition, McGraw-Hill, New York, 2000.
HAYWARD V ., ASTLEY O . R ., CRUZ - HERNANDEZ M ., GRANT D . and ROBLES - DE - LA - TORRE
G ., ‘Haptic interfaces and devices’, Sensor Review 24(1), 16–29, 2004.
KACZMAREK K ., WEBSTER J . G ., BACH - Y - RITA P . and TOMPKINS W. J ., ‘Electrotactile
and vibrotactile displays for sensory substitution systems’, IEEE Transactions
on Biomedical Engineering 38(1), 1–16, 1991.
COLLINS C . C ., Tactile television: mechanical and electrical image projection,
IEEE Transactions on Man–Machine Systems 11, 65–71, 1970.
GILAT T ., SHIBOLET S . and SOHAR E ., The mechanism of heatstroke, J. Trop. Med.
Hyg. 66, 204–212, 1963.
SOHAR E ., Man and Climate, Keter Publishers, Jerusalem, 1980.
SPURR G . B ., HUTT B . K . and HORVATH S . M ., Shivering, oxygen consumption and
body temperature in acute exposure of men to two different cold environments,
J. Appl. Physiol. 11, 58–64, 1957.
SOHAR E., Men, Microclimate and society, Energy and Buildings 4, 149–154, 1982.
SOHAR E ., Climate and society, Biometeorol. 4(1), 99–104, 1970.
KUNO Y ., Human Perspiration, Charles C. Thomas, Springfield, 1956.
RANDALL W . C ., ‘Quantitation and regional distribution of sweat glands in man’,
J. Clin. Invest. 25, 761–767, 1946.

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4
Tactile aspects of clothing comfort

4.1

Tactile comfort sensations

4.1.1

Human tactile responses

The tactile sensation of clothing is very important for clothing comfort.
Tactile comfort of clothing is based on the human sensory response to
clothing materials and is sensed by a variety of thermal, physiological
and mechanical stimuli [1, 2]. During wearing of clothing, the clothing
materials make contacts with the skin where numerous receptors are
located which give rise to various sensations felt by the wearer. Touch
and tactile properties are very important parameters to be considered for
fabrics that come into direct contact with the human skin. On wearing
clothing, the tactile sensations are mainly produced when clothing
contacts and impacts local skin of human body [3, 4]. The tactile
parameters of all these fabrics affect the clothing comfort, because the
sensory feel of clothing materials is dependent on the mechanical stimuli
due to pressure and frictional forces [2, 5]. When the clothing materials
come into contact with the human skin they stimulate the various
mechanoreceptors (e.g. free nerve endings, root hair plexus, Merkel’s
discs, Meissner’s corpuscles, Pacinian corpuscles and Ruffini corpusles)
present in the different layers of skin (i.e. epidermis, dermis and
subcutaneous zone). The face, the torso and the hand are the most tactile
sensitive skin areas of human body [6].
The textile fabrics are the thin sheet materials and the typical tactile
characteristics of textile materials are the flexibility, compressibility,
surface texture, extensibility, friction, etc. The surface and bulk properties
of textile fabrics are one of the most frequently used tactile characteristics
of fabrics. Fabric softness is a complex tactile sensation which determines
the initial tactile perception of a wearer towards the clothing even before
the wearing of the clothing. The fabric softness is commonly perceived by
pressing or squeezing with fingers. The softness or fullness sensations of
fabrics are objectively expressed by compressibility and resilience
characteristics. The fabric frictional characteristics influence the tactile

54

Tactile aspects of clothing comfort

55

sensations of clothing to a great extent. The Merkel’s discs and the Ruffini
endings play are mainly responsible for tactile sensations related to surface
texture and touch of fabric [7, 8]. Due to their location, receptive field
and response type, the Pacinian, the Merkel and the Meissner
mechanoreceptors can characterize the roughness of fabrics, whereas the
Ruffini and Meissner mechanoreceptors can characterize the friction
between skin and fabric [9]. The causes of the prickle from the skin contact
of fabric can be detected by the pain receptors [10].

4.1.2

Tactile characteristics of clothing

The low stress mechanical properties of fabrics (e.g., bending, shear,
extension) are objectively measured to assess the tactile characteristics of
fabrics. Kawabata Evaluation Systems for Fabrics (KES-F) and FAST
(Fabrics Analysis by Simple Tests) systems are available for measuring the
fabric handle related characteristics. But, as far as the tactile responses are
concerned, all the low stress mechanical characteristics directly or indirectly
stimulate the touch, pressure, roughness and other mechanoreceptors of
human skin.
The prickle sensation due to clothing is one of the most irritating
discomfort sensations for clothing wear next to skin. A special type of
pain nerve is responsible for prickle sensation. Individual protruding
fibre ends from a fabric surface are responsible for triggering the pain
nerve endings, when contacting the skin. Perceptions of prickle
sensations require combined responses from a group of pain nerves.
Fabric prickliness can be measured by using low pressure compression
testing, laser counting of protruding fibres and a modified audio pickup method [11]. Matsudaira et al. [11] modified Kawabata compression
tester (KESF-3) to measure the relationship between applied pressure
and fabric thickness at the initial stage of fabric compression, i.e. when
bending of fibres protruding from fabric surface takes place during
compression. WRONZ developed laser hairiness meter where the fibres
protruding from the fabric surface are counted by laser beam. This gives
fairly good indication of prickliness of fabric. The sensitivity of the
instrument was found inadequate for the detection of all the fabric
surface hairs, where the coarser and stiffer hairs are preferentially
detected [2]. Matsudaira et al. [11] also used a modified audio pick-up
technique (Fig. 4.1) for measuring the mean force per contact with the
protruding fibre. They have observed that this technique is the most
effective measure of fabric prickle and the result obtained from this
instrument correlated well with the subjective perception of fabric
prickle.

Tactile aspects of clothing comfort

57

Itchiness is also found to result from activation of some superficial pain
receptors. The perception of itchiness in clothing is highly correlated with
perception of prickliness and both the sensations are considered as
important tactile sensory components [12, 13]. The sensation of fabric
itchiness depends on the fibre diameter, fabric thickness at low and high
pressures, and fabric surface roughness [2].
The frictional interaction between fabric and skin during contact are
the key factors determining some of the important tactile sensations, i.e.
perceptions of roughness, smoothness and scratchiness. Presence of
moisture at the skin surface alters the intensity of fabric roughness
perceptions due to change in friction. As moisture content increases the
friction between skin and fabric surface increases, which results in
displacement of skin and thus more and more touch receptors are
stimulated. This is the reason for a fabric that is perceived to be comfortable
when a person is not sweating may be perceived to be uncomfortable under
sweating conditions [2].
Mehrtens and McAlister [14] reported that the scratchiness was the
greatest source of discomfort and in terms of scratchiness and clinginess
men are slightly more critical than women, which is due to the fact that
generally men perspire more than women. They have developed an
objective method to test the scratchiness of fabrics in which a fabric was
passed over a microphone yielded a scratchiness sound. In that method,
the fabric was moved at the speed of 7 yd/min across a brass sheet above
a microphone and the signal from microphone was then sent through an
integrating amplifier into a recorder. They have observed good correlation
between subjective sensation and objectively measured values of fabric
scratchiness, as shown in Fig. 4.3.

4.3 Subjecting and objective scratchiness ratings [14].

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Science in clothing comfort

4.2

Fabric handle attributes for expressing tactile
comfort

The quality of fabric is generally perceived through tactile sensations.
Consumers of textile products always touch the product before buying
them and the majority of rejections are due to poor hand. Improved
finishing, new fibres, speciality textile products are successful in clothing
industries mainly because of improvement in fabric handle. Fabric handle
may be defined as the human tactile sensory response towards fabric, which
involves not only physical but also physiological, perceptional and social
factors; this very fact complicates the process of fabric hand evaluation
tremendously [15–20]. The tactile comfort of clothing is the sense of touch
of fabric which is directly related to the fabric handle characteristics. Fabric
handle has been defined by the subjective assessment of a textile obtained
from the sense of touch [21] and can be assessed by measuring the low
stress mechanical characteristics and surface characteristics of fabrics. The
ease of motion and the level of pressure generated by the clothing on to
the human body are directly related to the tactile comfort characteristics
of clothing. Traditionally, the fabric handle characteristics are evaluated
subjectively by sensing the roughness, smoothness, softness, harshness,
flexibility, thickness, scratchiness, prickle, etc. against the skin. Objective
measurement of fabric handle may be of major commercial significance if
they, for example, assist in explaining handle assessment or provide some
information about the tactile sensations of fabrics. It is also necessary to
examine the subjective assessment of handle before examining its
relationship to fabric mechanical and surface properties. In textile and
garment industries the fabric handle is traditionally assessed subjectively.
Peirce [16] obtained objective measures of fabric handle, identified the
importance of bending, compression, specific volume, and surface
properties. Howorth and Oliver [22], for the first time, identified the three
quality attributes which directly affect the handle of suiting fabrics. These
quality attributes are surface smoothness, fabric stiffness and thickness. A
series of fabric handle attributes have been proposed by the “Japanese
hand evaluation and standardization committee for men’s clothing for
different climatic conditions” [23]. For men’s summer clothing, they have
identified four primary fabric handle related quality attributes, namely
fullness, springiness/stiffness, crispness and hardness. On the other hand,
for men’s winter suiting fabrics they proposed three main fabric handle
related quality attributes, namely smoothness, fullness, and springiness/
stiffness. They have also established standards to describe the intensity of
the above primary hand attributes on a 10 point scale. Studies [24–26]
have been done on the objective measurement of fabric handles by
measuring fabric low-stress mechanical and surface properties. The KES-

Tactile aspects of clothing comfort

59

F instruments were used to measure fabric tensile, shear, bending,
compression, and surface properties. Winakor et al. [27] have considered
the different physical characteristics of fabrics, like stiffness, roughness,
and thickness which represent the bending, frictional, and compressional
deformations, respectively, that occur in handling a fabric. They have
selected nine pairs of polar adjectives (i.e. limp–crisp, flexible–stiff, firm–
sleazy, scratchy–silky, fine–coarse, smooth–rough, soft–hard, light–heavy,
thin–thick) to express the tactile sensory attributes of fabrics which are
related with the fabric characteristics, i.e. low stress mechanical and other
physical properties. Figure 4.4 shows the interrelationships between fabric
characteristics and pairs of polar adjectives of tactile sensations.

4.4 Fabric characteristics and tactile attributes.

Kawabata [28] related the different fabric properties with the individual
hand expressions. Figure 4.5 shows the different hand expressions (given
within oval) proposed by Kawabata [28] and related fabric characteristics
(given within the rectangles). The hand expressions proposed by Kawabata
are in Japanese terms. The equivalent English terms are given in
parenthesis.

4.3

Assessment of fabric handle characteristics

4.3.1

Subjective assessment

Traditionally the handle characteristics of fabric are assessed subjectively.
The psychologically based subjective assessment of fabric handle is first
reported by Binns [29, 30]. He has proposed an early analysis of the
mechanism by which the fabric handle was assessed by judges. He found
that the judgment on fabric handle of a number of experienced judges

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4.5 Primary hand expressions and related fabric properties.

Tactile aspects of clothing comfort

61

gives a more reliable and accurate objective grading of fabric handle than
is possible from an individual judge’s grading. For the assessment of fabric
handle, researchers have adopted the factor analysis technique, where they
attempted to identify the underlying interrelationships in the handle
assessments of a range of fabrics. In the factor analysis the researchers
have isolated three important factors responsible for fabric handle, namely
smoothness, stiffness and bulk, where the fabric bulk is directly
proportional to area density and thickness of the fabric [31]. Attempts
have been made to assess the fabric handle characteristics subjectively
based on psychophysical concepts [32–34]. Psychophysical concepts from
both decision theory and information theory have been used and proposed
the four different sensory attributes which correspond to the four fabric
characteristics, namely smoothness, stiffness, bulk properties and warmth.
This psychophysical concepts theory is analogous to the Young-Helmholtz
theory [35], which proposes three colour receptors in the eye, one each
for red, green, and blue, for perceiving colour [36]. Kawabata [37, 38]
developed subjective assessment technique of fabric handle characteristics
based on two assumptions, i.e. (i) the assessment of fabric handle
characteristics was based on tactile sensations caused by fabric mechanical
and surface properties; and (ii) the final judgment of handle is based on
the suitability of the mechanical and surface properties for the particular
end use of the fabric. Kawabata subsequently developed a series of
instruments (KES-FB) for evaluating the objective assessment of fabric
handle characteristics by measuring various low stress mechanical
properties of fabrics. The Weber–Fechner law of psychophysics has been
adopted by Matsuo [32] during the subjective analysis of fabric handle
characteristics. The Weber–Fechner law intends to describe the relationship
between the physical magnitudes of stimuli and the perceived intensity of
the stimuli. Matsuo assumed that the Weber–Fechner law is applicable
when the fabric mechanical properties were used as the handle stimuli
and used a nonlinear combination of mechanical properties to explain fabric
handle assessments. In practice, the results obtained from this model depend
strongly on the values assigned to the minimum sensibility which a judge
can discriminate for each mechanical property.

4.3.2

Objective assessment

Researchers have been attempting to objectively measure the fabric hand
characteristics since 1970s. The outcomes of the intense researches are
the two instrumental approaches to measure the low stress mechanical
and surface characteristics of fabrics, i.e., the Kawabata Evaluation System
(KES) and Fabric Assurance by Simple Testing (FAST). These methods

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are based on correlations between a number of subjectively assessed
discrete fabric sensory attributes such as smoothness, firmness, fullness,
crispness and hardness, and corresponding mechanically measurable fabric
properties, i.e., low mechanical stress tensile, shear, bending, compression,
and surface friction [38, 39].
Kawabata evaluation system of fabric (KES-F)
Kawabata Evaluation System of Fabric (KES-F) has the following four
modules for measuring low stress and surface characteristics of fabrics,
(i)
(ii)
(iii)
(iv)

KES-F1 for measurement of tensile and shearing characteristics;
KES-F2 for measurement of bending characteristics;
KES-F3 for measurement of compressional characteristics;
KES-F4 for measurement of surface frication and roughness.

Figure 4.6 shows the principle of KESF-1 system. The fabric specimen
is clamped between two jaws (one attached with the drum for tensile force
application and other is attached with slide for shear force application)
and subjected to a constant tension of 10 gf/cm by a weight attached to the
drum on which one jaw is mounted. Tensile force is applied by allowing
the drum to rotate freely. The tensile force is measured by the tensile force
detector by measuring the torque and the tensile strain is measured by
tensile strain detector from the data of angle of rotation of the drum. The
shear force is measured by a transducer connected to the other jaw (attached
with slide) which moved sideways to apply the shear deformation. The
shear force is measured by the shear force detector by measuring the force
required to slide and the shear strain is measured by shear strain detector
from the data of the displacement of the slide.

4.6 Working principle of KESF-1 [40].

Tactile aspects of clothing comfort

63

The typical instrument settings, loading conditions and parameters
measured for tensile and shear characteristics in KESF-1 system are [41]
Tensile characteristics
Settings and loading conditions:
Rate of extension
– 0.1 mm/s;
Sample size (L×W)
– 5 × 20 cm;
Maximum tensile force – 5 N/cm.
Test parameters and units:
●
●

●
●

Elongation at 5 N/cm tension (EM) is expressed in percentage;
Energy required to extend the fabric specimen to 5 N/cm tension
(WT) is expressed in J/m2;
Linearity of stress-strain curve (LT) is unitless;
Tensile resilience (RT) is expressed in percentage.

Shear characteristics
Settings and loading conditions:
Speed of shearing
–
Sample size (L×W)
–
Maximum shear angle –
Constant sample tension –

0.417 mm/s;
5 × 20 cm;
±140 mrad;
0.1 N/cm.

Test parameters and units:
●
●
●

Shear rigidity at 39.4 mrad shear strain (G) is expressed in N/m;
Shear hysteresis at 8.7 mrad shear strain (2HG) is expressed in N/m;
Shear hysteresis at 87 mrad shear strain (2HG5) is expressed in N/m.

The principle of KESF-2 system is shown in Fig. 4.7. The fabric
specimen is gripped by two jaws. One jaw is attached with the bending
arrangement which moves in circular direction to apply bending force.
The other jaw is connected with torque sensor which detects torque value
of steel wire during bending of specimen. The curvature of bending is
obtained from the drive to the bending arrangement. The fabric specimen
is bent with the help of bending arrangement between the curvatures of 2.5 cm-1 and +2.5 cm -1.
The typical instrument settings, loading conditions and parameters
measured for bending characteristics in KESF-2 system are [41]

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4.7 Working principle of KESF-2 [40].

Settings and loading conditions:
Rate of bending
– 0.5 cm–1/s;
Sample size (L×W) – 20 × 1 cm;
Maximum curvature – ±2.5 cm–1.
Test parameters and units:
●
●

Bending rigidity at 1.5 cm–1 curvature (B) is expressed in μNm;
Bending hysteresis at ±0.5 cm–1 curvature (2HB) is expressed in mN.

Figure 4.8 shows the working principle of KESF-3 system. The fabric
specimen is compressed between two plates, i.e. anvil and the pressure foot.
The fabric specimen is placed on the anvil and pressure is increased with the
help of pressure foot, while continuously monitoring the sample thickness by
thickness detector. The compressive pressure is detected by the compressive
force detector. The pressure foot gets drive from the drive arrangement.
The typical instrument settings, loading conditions and parameters
measured for compression characteristics in KESF-3 system are [41]
Settings and loading conditions:
Rate of compression
– 0.02 mm/s
Area of circular pressure foot
– 2.0 cm2
Maximum compressive pressure – 5 kPa

Tactile aspects of clothing comfort

65

4.8 Working principle of KESF-3 [40].

Test parameters and units:
●

●
●
●
●

Thickness compression as a proportion of original fabric thickness
(EMC) is expressed in %;
Fabric thickness at 5 Pa pressure (TO) is expressed in mm;
Compression energy at 5 kPa pressure (WC) is expressed in J/m 2;
Linearity of compression curve (LC) is unit less;
Compressional resilience (RC) is expressed in %.

Friction and surface roughness characteristics of fabrics are measured
by KESF-4 system. The working principle is shown in Fig. 4.9, where
the surface roughness and surface friction of fabric specimen are being
measured at same time. The fabric specimen, kept at constant tension by
hanging dead weight, gets to-and-fro motion from a drum which rotates
intermittently in clockwise and anti-clockwise directions. The frictional
force between fabric specimen and the friction surface at the friction
point is detected by frictional force detector. The surface roughness of
the fabric is measured by surface roughness detection system, which is
basically a displacement sensor. The probe of the displacement sensor is
in touch with the fabric surface. When the fabric moves in the horizontal
plane, due to the surface roughness the probe deflects vertically. This
vertical deflection of the probe is the measure of surface roughness of
fabric.

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4.9 Working principle of KESF-4 [40].

The typical instrument settings, loading conditions and parameters
measured for friction and surface roughness characteristics in KESF-4
system are [41]
Frictional characteristics
Settings and loading conditions:
Traverse rate of fabric
Constant tension on fabric
Normal load
Maximum fabric movement

–
–
–
–

1.0 mm/s
0.1 N/cm
0.5N
3 cm

Test parameters and units:
●
●

Coefficient of surface friction (MIU) is unitless;
Mean deviation of MIU (MMD) is unitless;

Surface roughness
Settings and loading conditions:
Traverse rate of fabric
Constant tension on fabric
Contact force
Maximum fabric movement

–
–
–
–

1.0 mm/s
0.1 N/cm
0.1N
3 cm

Test parameters and units:
●

Mean deviation of fabric surface profile or geometrical surface
roughness (SMD) is expressed in μm.

Tactile aspects of clothing comfort

67

From all the above parameters, which are obtained from KESF
instruments the total handle value (THV) can be calculated, which is the
indicator of fabric handle behaviour of fabric.
Fabric assurance by simple testing (FAST)
The FAST system has been developed by CSIRO (Australia) primarily for
quality control and assurance of fabrics [42–44]. It also gives the objective
indication of fabric handle characteristics. It consists of a series of three
instruments (i.e. FAST-1: Compression meter; FAST-2: Bending meter;
and FAST-3: Extension meter) and a test method (FAST-4: Dimensional
stability test) which are inexpensive, simple to use and robust in
construction. It measures properties which are closely related to the ease
of garment manufacturing, handle characteristics and the durability of
surface finishing.
FAST-1
Figure 4.10 shows the schematic diagram of FAST-1system, i.e.
compression meter. It measures the fabric thickness over a range of loads,
the variability and the durability of the thickness of the fabric surface
layer. It can measure fabric thickness to micrometer resolution at two
predetermined loads, and thereby enables the accurate measurement of
surface layer thickness. The fabric thickness (T) is measured at a pressure
of 2 gf/cm2. Surface thickness (ST) is the difference in thickness of a fabric
measured at pressures of 2 gf/cm2 and 100 gf/cm2. This gives information
about the hairiness or surface bulk of the fabric (closely related to surface
treatment like brushing, singeing, finishing etc.). Released surface
thickness (STR) is the measure of the surface thickness after the fabric is
exposed to steam or water. The increase in fabric surface thickness obtained
by this steaming process simulates the actual changes in surface
characteristics that occur during the actual use of garment.

4.10 Principle of FAST-1system.

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FAST-2
The schematic diagram of FAST-2 system, i.e. bending meter, which
measures the bending length (BL) and bending rigidity (B) of fabric, is
shown in Fig. 4.11. The instrument measures the fabric bending length
according to BS 3356-1961. The fabric bending length simulates the
draping behaviour of fabric and the bending rigidity is related to the quality
of stiffness when a fabric is handled. The bending rigidity is particularly
crucial in the tailoring of lightweight fabrics as a very flexible fabric (low
bending rigidity) may cause seam puckering while a high bending rigidity
fabric can be more manageable in sewing and so produce a flat seam. The
operator error in aligning the sample is eliminated with the use of an optical
sensor. The bending length is displayed automatically, so chances of the
error due to the operator’s judgment are not there.

4.11 Principle of FAST-2 system.

FAST-3
Figure 4.12 shows the schematic diagram principle of FAST-3 system, i.e.
extension meter, for measuring fabric extension. It measures extensibility
of fabric at various loads as well as its shear rigidity. It is capable of
measuring the fabric extensibility in warp, weft and bias directions over a
range of loads, with direct reading of extension as a percentage of the
initial gauge length. The fabric extension is displayed as a percentage with
a 0.1% resolution. Extensibility is measured at three loads 5 gf/cm (E5),
20 gf/cm (E20) and 100 gf/cm (E100). The difference in fabric
extensibilities at between E5 and E20 is used to calculate fabric formability,
which is a parameter related to the incidence of seam pucker. Fabric
extensibility is combined with bending rigidity to calculate the fabric
formability (F), which is a measure of the ability of a fabric to absorb
compression in its own plane without buckling. E100 is used in FAST
control chart (FAST fabric fingerprint) as the measure of fabric
extensibility. If the value is below approximately 2%, then the fabric will
be difficult to extend during seam overfeed.

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Shrinkage (RS) and Hygral Expansion (HE), which can test these parameters
in less than an hour as compared to the conventional one-day test. The drying
is done in a forced convection oven. A template and a ruler are the only
equipments required to do the test. The results from this method simulates
the change in fabric dimensions that may occur during the actual wear as
the fabric is subjected to washing and changing humidity conditions. The
relaxation shrinkage is mainly due to the recovery of fabric structure which
got strained during manufacturing, while hygral expansion or contraction is
caused by the swelling or deswelling of hygroscopic fibres. Very high
relaxation shrinkage results in problem of change of garment size, puckering,
etc. Similarly, higher hygral expansion may result in seam pucker, fabric
waviness, buckling and overall poor garment appearance.
The testing is completed in following three different steps (Fig. 4.14),
●

●

●

Step-I

– the fabric specimen is first over dried (up to 0% moisture)
to measure its dry dimensions (l1);
Step-II – soaked in water to measure its wet relaxed dimensions
(l2);
Step-III – the specimen is dried again to measure its final dry
dimensions (l3).

The relaxation shrinkage (RS) and the hygral expansion (HE) are
calculated from the above dimensions, using following relationships:
Relaxation shrinkage (RS) = [(l 1 – l 2) × 100] ÷ l1
Hygral expansion (HE) = [(l 2 – l 3) × 100] ÷ l3

4.14 Steps to test the dimensional stability in FAST-4 [43].

… (4.2)
… (4.3)

Tactile aspects of clothing comfort

71

The FAST data analysis software, which is included as part of the FAST
System package, automatically plots the appropriate values and joins the
various plotted points together to form a fabric ‘FAST control chart’ or
‘FAST fingerprint’, which is unique to each particular fabric. Figure 4.15
shows a typical FAST control chart. Each value has a separate scale showing
a graphical representation of the range of values in the appropriate units
that we expect for each of the various measurements. For example
relaxation shrinkage ‘RS-1’ represents the warp value and ‘RS-2’ that of
the weft. In addition to the values for the various measurements, each
scale contains one or more shaded zones. If the fingerprint falls into one
of these zones, a potential problem with the particular aspect(s) of fabric
performance influenced by that property is indicated.

4.15 Typical FAST control chart.

Fabric extraction principle
The fabric extraction principle is not a new idea at all; it has been a common
practice for many years by ladies in certain parts of the world when
searching for a desired scarf at a market. They would take off their rings
and pull out a scarf through the ring, judging the overall quality of the
scarf based on the resistance during the pulling out process [17]. The fabric

72

Science in clothing comfort

is extracted through a specially designed nozzle and the force required to
extract the fabric through the nozzle is measured. During this extraction
process the sample is deformed under a very complex yet low stress state
including tensile, shearing and bending as well as frictional actions, similar
to the stress state when we handle a fabric. The fabric specimen gets folded,
sheared, rubbed, compressed and bent during extraction. A large number
of studies [17, 45–51] have been reported where fabric extraction technique
is used for evaluation of fabric hand.
In one of these studies [50] a circular fabric specimen, 250 mm in
diameter held by a pin, is drawn through a cylindrical nozzle of highly
polished steel, 20 mm in diameter and 20 mm in height, as shown in
Fig. 4.16.

4.16 Fabric extraction technique.

The fabric sample should be free from wrinkles and creases. As the top
jaw, with which the connecting pin is attached, moves upward, it extracts
the circular fabric specimens through the nozzle. The force required to
extract the fabric specimen through the nozzle changes as more and more
of the specimen is introduced into the nozzle. The extraction force can be
recorded by the instrument. A typical extraction force–displacement curve
is shown in Fig. 4.17.
The fabric handle behaviour has been defined by two parameters:
(i) peak extraction force and (ii) traverse at peak extraction force. Traverse
at peak extraction force is the movement of the cross-head from where the
fabric sample starts exerting resistance to extraction till the force reaches
to its maximum. Both these parameters can be obtained from force–
displacement curves. Higher peak extraction force indicates stiffer fabric
and higher traverse at peak extraction force value shows the fabric surface
become smoother. The extraction force is the combination of fabric
resistance to bending, compression, shear, extension and sliding.

Tactile aspects of clothing comfort

73

4.17 Typical extraction force–displacement curve.

4.4

Fabric parameters affecting tactile sensation

Fabric roughness and scratchiness are the important characteristics which
directly affect the tactile sensation of clothing. It has been reported [2]
that the sensation of roughness correlated with fabric surface roughness
characteristics (frictional force, mean surface roughness coefficient, and
deviation of surface roughness coefficient), compressional characteristics
of fabrics (compressibility and compressional energy), fibre diameter,
tensile characteristics of fibre (breaking load and breaking elongation),
and tensile characteristics of fabric (breaking elongation, elastic recovery).
The sensation of scratchiness, on the other hand, is related to fabric tensile
characteristics (breaking elongation, work of rupture and the modulus),
fabric surface roughness (frictional force, mean surface roughness
coefficient, and deviation of surface roughness coefficient), compressional
characteristics of fabrics (compressibility, linearity of the compression
curve, compressional energy and slope of the compression-thickness
curve).
In a study on roughness sensation of woven and knitted fabrics made
from nylon monofilaments of different diameters [52], it has been reported
that the perception of roughness increases with the increase in filament
diameter and knitted fabric is rougher than the woven fabric made from
the same diameter filament (Fig. 4.18).
It has been reported that prickle sensation of fabric is directly correlated
with fibre diameter, fabric thickness at low loading, and fabric surface
roughness [53]. It has also been reported [54] that the prickle sensation of
the fabrics could be predicted from the density of coarse fibre ends per
unit area of fabric and the variations in diameter distribution in individual
fibre mass, especially the percentage of coarse fibre ends, influence the
fabric prickle sensation significantly.

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Fabric warmness and heaviness also cause discomfort. The rating of
the tactile sensation of heaviness alone is very low. Since heaviness is
related to warmness, the two sensations have been combined by Mehrtens
and McAlister [14]. They have reported that warmness might be more
dependent on fabric thickness than on weight, and that heaviness might
be more dependent on weight than on thickness. It has been reported that
the product of fabric weight and fabric thickness was a better objective
measurement for correlation with warmness and heaviness than either
weight or thickness alone [14].
The tactile comfort sensations can be greatly improved by different types
of finishing treatments at fabric as well as in the garment stage. There are
many finishing treatments, namely silicon finish, nano-finish, brushing,
etc., for improvement of tactile sensation of fabrics. It may be said that
“cloth is made in the finishing”. The treatments are performed on fabrics
with the help of chemical or mechanical treatments at the last step in the
textile production before the clothing operations or even after garmenting.
The type of finishing treatment and different process parameters affect
the tactile sensation in a significant way.

References
1.
2.
3.
4.

5.
6.
7.
8.
9.
10.

BARKER R. L.,

‘From fabric hand to thermal comfort: The evolving role of objective
measurements in explaining human comfort response to textiles, Int. J. Clothing
Sci. Technol. 14(3/4), 181–200, 2002.
LI Y ., ‘The science of clothing comfort’, Textile Progress, editor LAYTON J . M .,
The Textile Institute, Manchester, Vol. 31, 2001.
HOLLINS M ., BENSMAIA S ., KARLOF K . and YOUNG F ., Perception Psychophysics
62(2000), 1534.
PAN N ., KAISER S ., CHANDLER J ., DALLAS M . J ., BRANDT B ., CAMERON B ., BROWN D . and
BURNS L ., Fabric hand evaluation: perception and instrumentation, in
Proceedings of the International Textile and Apparel Association Annual
Meeting, Dallas, Nov. 1998.
GEE M. G ., TOMLINS P ., CALVER A ., DARLING R . H ., and RIDES M ., ‘A new friction
measurement system for the frictional component of touch’, Wear 259(7–12),
1437–1442, 2005.
LEDERMAN S . J ., Skin and Touch: Encyclopedia of Human Biology, 2nd edition,
Vol. 8, Academic Press, San Diego, 1997.
JIANG W ., TREMBLAY F ., and CHAPMAN C . E ., ‘Neural encoding of texture changes
in the primary and the secondary cortical areas of monkeys during passive texture
discrimination’, J. Neurophysiol. 77(3), 1656–1662, 1997.
CONNOR C . E ., HSIAO S . S ., PHILLIPS J . R ., and JOHNSON K . O ., ‘Tactile roughness:
neural codes that account for psychophysical magnitude estimates’, J. Neurosci.
10, 3823–3836, 1990.
BUENO M. A. and RENNER M., ‘De l’Etoffe à la Main’, Pour la Science 266, 144–149,
1999.
GARNSWORTHY R . K ., GULLY R . L ., KANDIAH R . P ., KENINS P ., MAYFIELD R . J ., and

Tactile aspects of clothing comfort

11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
31.
32.

77

WESTERMAN R . A ., Understanding the causes of prickle and itch from the skin
contact of fabrics, Report No G64, Australasian Textiles 8(4), 26–29, 1988.
MATSUDAIRA M ., WATT J . D . and CAMAB, G . A ., ‘Measurement of the surface prickle
of fabrics. Part I: The evaluation of potential objective methods, J Text. Inst.
81, 288–299, 1990.
LI Y . Dimensions of comfort sensations during wear in a hot condition, Submitted
to J. Federation of Asian Textile Associations.
LI Y . ‘Dimensions of sensory perceptions in a cold condition’, J. Chitta Text.
University 15(3), 50–53, 1998.
MEHRTENS D . G . and MCALISTER K . C ., ‘Fiber properties responsible for garment
comfort’, Textile Res. J. 32, 658–665, 1962.
BINNS H ., ‘The discrimination of wool fabrics by the sense of touch’, Br. J.
Psychiatry 16, pp. 237–247, 1926.
PEIRCE F . T ., ‘The ‘handle’ of cloth as a measurable quantity’, Journal of the
Textile Institute 21, pp. T377–416, 1930.
B R A N D R . H ., ‘Measurement of fabric aesthetics: analysis of aesthetic
components’, Textile Research Journal 34, p. 791, 1964.
VAUGHN E . A . and KIM C . J ., Study on Fabric Hand, Parts I, II, and III, Technical
Conference, American Association of Textile Chemists and Colorists, 1975.
ELKS B . C . and CARNSWORRTHY R . K ., ‘A review of techniques for the assessment
of hand’, Textile Research Journal, 50, p. 231, 1980.
PAN N ., ‘Quantification and evaluation of human tactile sense towards fabrics’,
Int. Journal of Design & Nature, 1(1), 1–13, 2006.
Textile Terms and Definitions, 8th edition, The Textile Institute, Manchester, 1986.
HOWORTH W. S ., and OLIVER P . H ., ‘The application of multiple factor analysis to
the assessment of fabric handle’, J. Textile Inst., 49(T540-T553), 1958.
KAWABATA S ., HESC Standard of Hand Evaluation, Vol. 2, The Textile Machinery
Society of Japan, 1980.
MAHAR T . J ., DHINGRA R . C ., and POSTLE R . Measurement and interpretation of lowstress fabric mechanical and surface properties, Part I: Precision of measurement,
Textile Res. J. 57, 357–369, 1987.
DHINGRA R . C ., LIU D . and POSTLE R ., Measuring and interpreting low-stress fabric
mechanical and surface properties, Part II: Application to finishing, dry-cleaning
and photo degradation of wool fabrics, Textile Res. J. 59, 357–368, 1989.
POSTLE R . and DHINGRA R . C ., Measuring and interpreting low-stress fabric
mechanical and surface properties: Part III: Optimization of fabric properties
for men’s suiting materials, Textile Res. J. 59, 448–459, 1989.
WINAKOR G ., KIM C . J . and WOLINS L ., Fabric hand: tactile sensory assessment,
Textile Res. J. 50, 601–610, 1980.
KAWABATA S . editor, ‘The standardization and analysis of hand evaluation’, 2nd
edition, HESC, The Textile Machinery Society of Japan, Osaka, Japan, 1980.
BINNS H ., ‘A comparison between the judgments of individuals skilled in the
textile trade and the natural judgments of untrained adults and children’, J.
Textile Inst. 17, T615, 1926.
BINNS H ., ‘The discrimination of wool fabrics by sense of touch’, J. Psychol.
1263, 7, 1926.
HOWORTH W. S . and OLIVER P . H ., ‘The application of multiple factor analysis to
the assessment of fabric handle’, J. Textile Inst. 49, T540, 1958.
MATSUO T ., NASU N. and SAITO M., ‘Study of hand. Part 2: The method of measuring
hand’, J. Textile Mach. 17(03), 92, 1971.

78
33.
34.
35.
36.
37.
38.
39.
40.
41.
42.
43.
44.
45.
46.
47.
48.
49.
50.
51.
52.
53.
54.

Science in clothing comfort
LUNDGREN H . P ., ‘New concepts in evaluating fabric handle’, Textile Chem. Color.
1 (1), 35, 1969.
HILGARD E . R . and ATKINSON R . C ., Introduction to Psychology, 4th edition,
Harcourt, Brace and World Inc., New York, 1967.
HILGARD E . R ., and ATKINSON R . C ., Introduction to Psychology, 4th edition,
Harcourt, Brace and World Inc., New York, 1967.
MAHAR T . J . and POSTLE R ., ‘Measuring and interpreting low-stress fabric
mechanical and surface properties. Part IV: Subjective evaluation of fabric
handle’, Textile Res. J. 59, 721–733, 1989.
KAWABATA S ., The Standardization and Analysis of Hand Evaluation, The Textile
Machinery Society of Japan, Osaka, 1975.
KAWABATA S ., The Standardization and Analysis of Hand Evaluation, 2nd edition,
The Textile Machinery Society of Japan, Osaka. 1980.
PAN N ., ZERONIAN S . H ., and RYU H . S ., ‘An alternative approach to the objective
measurement of fabrics’, Textile Res. J. 63, 33–43, 1993.
KOTHARI V . K ., Progress in Textiles:
Science & Technology, Vol. 1, Testing
and Quality Management, IAFL Publications, New Delhi, 1999.
RADHAKRISHNAIAH P ., TEJATANALERT S . and SAWHNE A . P . S ., ‘Handle and comfort
properties of woven fabrics made from random blend and cotton-covered cotton/
polyester yarns’, Textile Res. J. 63, 573–579, 1993.
http://www.csiro.au
MINAZIO P . G ., ‘FAST – Fabric Assurance by Simple Testing’, International
Journal of Clothing Science and Technology 7(2/3), 43–48, 1995.
TESTER D. and DE BOOS A., ‘Get it right FAST time’, Textile Horizons 10(8), 13, 1990.
ALLEY V . L ., Nozzle extraction process and handle meter for measuring handle,
US Patent 4103550, 1 August, 1978.
KIM J. O. and SLATEN B. L., Objective Evaluation of Fabric Hand Part I: Relationships
of Fabric Hand by the Extraction Method and Related Physical and Surface
Properties, Department of Consumer Affairs, Auburn University, Auburn.
KIM J . O . and SLATEN B . L ., ‘Objective evaluation of fabric hand. Part I:
Relationships of fabric hand by the extraction’, Textile Res. J. 69, 59–67, 1999.
RADHAKRISHNAIAH P. and TEJATANALERT S., Handle and Comfort Properties of Woven
Fabrics Made from Random Blends and Cotton-Covered Cotton/Polyester Yarn,
School of Textile and Fiber Engineering, Georgia Institute of Technology, Atlanta.
PAN N ., ZERONIAN S . H ., ‘An alternative approach to the objective measurement of
fabrics’, Textile Res. J. 63(1), 33–43, 1993.
ISHTIAQUE S . M ., DAS A ., SHARMA V ., JAIN A . K ., ‘Evaluation of fabric hand by
extraction method’, Indian Journal of Fibre & Textile Research 28(2), 197–
201, 2003.
GROVER G ., SULTAN M . A ., SPIVAK S . M ., ‘A screen technique for fabric handle’, J.
Textile Ins. 84, 1–9, 1993.
BEHMANN F . W . ‘Tests on the roughness of textile surfaces’, Melliand Textilber
71, E199-200, 1990.
LI Y. and KEIGHLEY J . ‘Relations between fiber, yarn, fabric mechanical properties,
and subjective sensory responses in wear trials’, in Proceedings of the 3rd
International Conference on Ergonomics, Helsinki, Finland, 1988.
NAYLOR G . R . S ., PHILLIPS D . G . and VEITCH C . J . ‘Fabric-evoked prickle in worsted
spun single jersey fabrics. Part I: The role of fiber end diameter characteristics’,
Text. Res. J. 67, 288–295, 1997.

5
Thermal transmission

5.1

Introduction

Thermal comfort of a clothing system is associated with the thermal balance
of the body and its thermoregulatory responses to the dynamic interactions
with the clothing and the environment. Not only the heat but also moisture
transmission behaviour of a fabric plays a very important role in
maintaining thermo-physiological comfort. The fabrics should allow
moisture, both in the form of sensible and insensible perspiration, to be
transmitted from the body to the environment in order to cool the body
and reduce the chances of drop in thermal insulation of the fabric due to
accumulation of moisture within the micro-climate region. If the clothings
those are in contact with the skin are not dry, then the heat flow from the
body increases, which results in unwanted loss in body heat. This also
results in a clammy feel. It is necessary to design fabrics with required
moisture transmission properties for a specific end-use. In actual wear
conditions the transmission of moisture and heat through the clothing
system takes place in steady state as well as transient conditions. The human
body is rarely in a thermal steady state, but is continuously exposed to
transients in physical activity and environmental conditions [1].
Comfort is a pleasant state of psychological, physiological and physical
harmony between the human being and the environment [2]. The processes
involved in human comfort are physical, thermo-physiological, neurophysiological and psychological. Thermo-physiological comfort is
associated with the thermal balance of the human body, which strives to
maintain a constant body core temperature of about 37°C and a rise or fall
of ±5°C can be fatal. Hypothermia and hyperthermia may result,
respectively, due to the deficiency or excess of heat in the body, which is
considered to be a significant factor in limiting work performance.

5.2

Thermo-regulation in human body

The core temperature of the human body is biologically maintained within
a narrow range, close to 37°C during rest. It is independent of even large

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variations in environmental temperature. The core temperature is usually
measured as rectal temperature. However, the temperature in the core is
not uniform, but varies among the different body organs depending on the
local heat balance; some organs are heated by the blood flow and others
cooled by the blood flowing through them. During physical activity the
core temperature rises proportionally with the intensity of the activity
level [3]. The rise in temperature varies from person to person and is
proportional to their maximum oxygen uptake.
The temperature of skin surface of a naked person varies widely between
different locations. The body parts situated farthest from point of origin
of heat, for example, hands and feet, are generally cooler than the
temperatures on other parts of the body. The average skin temperature is
an area weighted mean which can be calculated from several surface
temperature measurements and it varies with the ambient temperature, but
it is independent of work intensity if heat balance can be maintained.
Temperature regulation is achieved by an autonomic regulation which
matches the rate of heat loss to that of heat production [4]. The centres for
this regulation are located in the hypothalamus, which is an important
part governing autonomic nervous system.
Neuro-physiological studies have shown that temperature sensors in
the brain respond to local thermal stimulation. Other cells in the
hypothalamus receive information from skin thermo-receptors or other
brain areas and interact by modifying the signal from the first-mentioned
sensors and control the activity of the thermal effectors. Other regions of
the body, such as the spinal cord and the abdomen, contain thermal sensors
responding to the local temperatures [5].
Many models for the thermoregulation system have been suggested
which describe the interaction between core and surface temperature signals
and their relative importance. Most models imply a thermostat principle,
with a reference set-point. A deviation from this reference point drives the
appropriate thermal response (sweating, heavy breathing, constriction,
shivering and non-shivering). The sensitivity of such proportional control
system in the hypothalamus may be controlled by skin sensors, physical
activity, etc. Some of the non-thermal factors, such as electrolyte balance
and hydration state, also have influence on temperature regulation and on
the sensitivity of the regulation mechanisms. Increased sweat secretion
and diminished electrolyte loss in the sweat are the most important
mechanisms in temperature regulation. As far as the acclimatization of
human body to cold environment is concerned only insignificant changes
occur. The most important is a local adaptation due to cold involving
vasodilatation in the hands and face [6].

Thermal transmission

5.3

81

Thermal distress

When a person is exposed to extreme environments (too hot or too cold)
the threshold limits for the thermoregulation system may reach quickly,
and thus control over the thermoregulatory system is lost [7]. During
activity in extreme hot environments, the rate of sweating and the rate of
evaporation of sweat controls the heat loss from human body. If the heat
loss is insufficient, the core temperature will increase above the controlled
level (i.e. hyperthermia). This, in combination with dehydration due to
sweat loss, may lead to heat exhaustion, when the person cannot continue
the activity, blood pressure drops and he may faint. This condition may
eventually lead to heat stroke, where sweating stops and core temperature
rises to very high levels. Other acute effects of thermal distress are heat
cramps, dehydration and heat edema. In addition, thermal distress of skin,
namely heat rash and failure of the sweat glands may also appear. On the
other hand, in extreme cold environments, the heat loss is greater than the
production which causes the body core temperature to fall. This condition
is known as hypothermia and it becomes increasingly severe as the body
temperature falls. At a core temperature of 35–36°C the person becomes
confused, shivering stops and the decline of core temperature occurs at a
faster rate. At about 30°C, the person becomes unconscious, and the heart
will stop beating at about 27°C. However, people can be brought to
consciousness by proper re-warming, even from very low core temperatures
[8, 9, 10]. Acute cold injuries also include frostbite and other frost injuries.
Short-term heat and cold hazards may be experienced in indoor situations,
for example in industrial work. In steel plants and the glass industry etc.
the workers may be exposed to heat stress. Cold store rooms and freeze
rooms in the food producing industries may cause cold discomfort and
hypothermia. Cases of hypothermia have been reported in elderly persons
even in normal environments, where they have been too weak or too poor
to protect themselves against the cold in their homes.
Heat load causes annoyance at work, increases strain on the
cardiovascular system, and evokes other thermoregulatory adjustments [1].
Chronic after-effects of acute heat illnesses are, among others, reduced
heat tolerance, malfunctioning of sweat glands, reduced sweating capacity,
muscle soreness and stiffness, reduced mobility, chronic heat exhaustion,
and cellular damage in different organs, particularly in the central nervous
system, heart, kidneys and liver. Cumulative effects of long-term exposures
to work in hot environments results in chronic heat exhaustion; the illness
being characterized by a set of symptoms including headache, gastric pain,
sleep disturbance, irritability, abnormally rapid heartbeat, vertigo and
nausea. After many years of work in the heat, the symptoms gradually
become worse and there can be observed hypertension, reduced libido,

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sexual impotency, myocardial damage, non-malignant diseases of the
digestive organs, and anaemia [11, 12].
Long winters and long periods of exposure to cold have harmful human
effects such as an increased rate of cardiovascular disease mortality. The
anginal pain typical of coronary heart disease can be provoked by different
types of cold stimulation, and changes appear in the electrocardiogram.
Both systolic and diastolic blood pressures are higher in the cold than at
room temperature. Furthermore, it has been observed that acute cold
increases the systolic blood pressure, even in healthy people who are in
generally good physical condition. Together, cold weather and physical
strain are considered risk factors, especially for those middle-aged and
elderly persons who suffer from latent or manifest disease of the circulatory
or respiratory systems [9]. Besides coronary heart disease, exposure to
cold increases the symptoms of other diseases such as rheumatoid arthritis,
some respiratory diseases (asthma, chronic bronchitis), and various skin
diseases. Very common are the symptoms and signs of dry skin and nasal
mucosa, which are indications of repeated exposure to cold.

5.4

Thermoregulation through clothing system

The human body continuously generates heat by its metabolic processes.
The heat is lost from the surface of the body by convection, radiation,
evaporation and respiration. In a steady-state situation, the heat produced
by the body is balanced by the heat loss to the environment. The human
body has a very intelligent thermoregulatory system to ensure the body
core temperature is maintained around 37°C. When the body temperature
increases higher than the set value, vasodilatations of blood vessels are
activated to increase the blood flow to the skin for the purpose of increasing
heat loss. If the body temperature continues to rise, the sweating
mechanisms will be activated to accelerate heat loss by evaporation of the
liquid sweat. In contrast, when the body detects its temperature decreased
lower than the set value, vasoconstriction of blood vessels will be activated
to decrease the blood flow to the skin to reduce heat loss, and the metabolic
rate will be increased by stimulating the muscles, which results in shivering
[13]. The thermoregulation system of human is schematically shown in
Fig. 5.1.
A person can live comfortably only in a very narrow thermal environment
from 26 to 30°C without wearing clothing [14]. With clothing, human
beings can live and perform various physical activities comfortable in a
wide range of thermal environments from -40 to 40°C. So, clothing plays
an important role in providing thermal protection for the human body and
creates a comfortable thermal microclimate so that one can survive and

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83

5.1 The human body thermoregulation system.

live in the thermal environments in which our body cannot cope up alone.
Therefore, thermal functional design of clothing is critically important for
human health and comfort, and in extreme cases, it can be a matter of life
and death.
The body continuously produces heat which must be transferred to the
environment. The release of body heat mainly takes place through the skin.
The body heat is transported to the skin through the circulation of blood
and from skin it is transferred to the environment. Our body always
generates metabolic heat due to the internal biological and physical
activities of the muscles and organs, the amount of which depends on the
intensity of the activities. Figure 5.2 shows that the thermal exchange
between body and environment takes place through heat conduction,
convection and radiation. In addition to heat transfer the exchange of body
moisture takes place through perspiration and sweating.
The thermal protection characteristics of clothing are essential function
in most of the environmental conditions in various parts on the earth. The
general clothing assemblies approximately covers around 90% of a human
body. Therefore, the thermal transmission characteristics of clothing are
extremely important, as our body responds to the external thermal
environment through clothing.
The thermoregulation mechanism through clothing depends primarily
on the thermal behaviours in human body and transmission characteristics
of clothing and can be summarized as [15, 16],
●

The biological thermal activities in the human body, namely metabolic

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5.2 Thermoregulation through clothing.

●

●

●

heat generation human body, blood circulations between different
parts of the body to transfer energy, sweating, shivering, the
interactive thermal activities between the human body and the external
environment through the skin (by conduction, convection and
radiation), heat loss due to evaporation of moisture through
perspiration and sweating.
The heat transmission through clothing ensemble (by conduction,
convection and radiation) and the latent heat of various phase changes
in clothing materials, such as the heat transferred by the processes of
condensation or evaporation and freezing or melting.
The moisture transfer process in clothing, involving water vapour
diffusion and convection in the void space within the textile structure,
moisture diffusion in fibres, liquid water diffusion through capillary
channels in textile materials, moisture condensation / evaporation
and freezing/melting etc.
The thermal barrier between the human body and the environment
formed by the clothing ensemble and entrapped still air influence
the heat and mass transmission from human body to the environment
or vice versa in the form of heat and moisture (both liquid and vapour)
transfer processes. In fact the heat and moisture transfer processes
are normally coupled under transient situations.

The metabolic heat generation is determined by metabolic activity.
Table 5.1 shows the approximate range of body heat production for an
average male for different types of activity.

Thermal transmission

85

Table 5.1 Typical range of metabolic heat generation for various
activities [17].

Activities

5.4.1

Metabolic heat generation
(W/m2)

Resting
Sleeping
Seated quietly
Standing

35–35
55–65
65–75

Normal walking on the level
3 km/h
5 km/h
7 km/h

110–120
150–160
210–220

Indoor activities
Reading
Writing
Working on computer
Filing, seated
Filing, standing
Lifting/packing

50–60
55–65
60–70
65–75
75–85
120–130

Miscellaneous work
Cooking
Dancing
Playing tennis
Playing basketball

90–110
140–200
200–300
300–450

Human as blackbody

In physics, a black body is an object that absorbs all electromagnetic
radiation that falls on it. No electromagnetic radiation passes through it
and none are reflected. Because no visible electromagnetic radiation (i.e.
light) is reflected or transmitted, the object appears black when it is cold.
If the black body is hot, these properties make it an ideal source of thermal
radiation. If a perfect black body at a certain temperature is surrounded by
other objects in thermal equilibrium at the same temperature, it will on
average emit exactly as much as it absorbs, at every wavelength [18]. A
black body at certain temperature (T) emits exactly the same wavelengths
and intensities which would be present in an environment at equilibrium
at temperature (T), and which would be absorbed by the body. Since the
radiation in such an environment has a spectrum that depends only on
temperature, the temperature of the object is directly related to the
wavelengths of the light that it emits. At normal room temperature the
black bodies generally emit mostly infrared light, with the increase in
temperature these start to emit visible lights.

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Human body can also be considered as black body. For example, some
of the person’s energy is radiated away in the form of electromagnetic
radiation, most of which is infrared. The net power radiated is the difference
between the power emitted and the power absorbed [18]:
Pnet = Pemit – Pabsorb

(5.1)

The total energy radiated by an adult male in one day is about 2000
kcal (food calories). Primary metabolic rate for a 40-year-old male is about
35 kcal/(m2·h), which is equivalent to 1700 kcal per day assuming the 2
m2 area. However, the mean metabolic rate of an adult without any activity
is about 50–70% greater than their basal rate [19].
There are other important thermal loss mechanisms, including
convection and evaporation. Conduction is negligible since the Nusselt
number (i.e. the ratio of convective to conductive heat transfer) is much
greater than unity. Evaporation (perspiration) is only required if radiation
and convection are insufficient to maintain a steady state temperature.
The heat loss by radiation is 2/3 of thermal energy loss in cool, still air.
Given the approximate nature of many of the assumptions, this can only
be taken as a crude estimate. Ambient air motion, causing forced
convection, or evaporation reduces the relative importance of radiation as
a thermal loss mechanism [20].

5.5

Thermal comfort of clothing

The human body is affected by various external conditions in the winter
and summer seasons. These external conditions can include changes in
ambient temperature, vapour pressure, air velocity, and clothing insulation,
among other factors that affect skin temperature [21]. On the other hand,
the body continuously produces heat, which must be transferred to the
environment. People sometimes feel uncomfortable as a result of some of
their physical activities due to the change of external conditions. The
temperature and humidity of the environment may profoundly influence
the body’s skin and interior temperature [22]. The human body is adapted
to function within a narrow temperature range. Generally, the human body
keeps its body temperature constant at 37 ± 0.5°C under different climatic
conditions.
Human thermal comfort depends on combinations of clothing, climate
and physical activity [23]. The human body converts the chemical energy of
its food into work and heat. The amount of heat generated and lost varies
markedly with activity and clothing levels [24]. The heat produced is
transferred from the body’s skin to the environment. In a steady-state heat
balance, the heat energy produced by the metabolism equals the rate of heat

Thermal transmission

87

transfer from the body by conduction, convection, radiation, evaporation
and respiration [25]. Therefore, clothing is needed to protect the body against
climatic influence and to assist its own thermal control functions under
various combinations of environmental conditions and physical activities
[23]. The heat loss from the body and the feeling of individual comfort in a
given environment is much affected by the clothing worn [26].

5.5.1

Heat exchange through clothing

In case of a steady-state heat balance condition of human metabolism
system the heat energy produced by metabolism should be equal to the
rate of heat transferred from the body. The body heat is transmitted through
conduction, convection, radiation evaporation and respiration. The basic
thermodynamic process in heat exchange per unit body surface area (W/
m2) between human and the environment is expressed by the general heat
balance equation [16, 17, 27, 28];
M – W = C + Ck + Cres + R + Eres + Esk

(5.2)

where M is metabolic rate, i.e. internal energy production; W is external
work; C is heat loss by convection; Ck is heat loss by conduction; Cres is
sensible heat loss due to respiration; R is heat loss by radiation; Eres is
evaporative heat loss due to respiration; and Esk is heat loss by evaporation
from the skin. The external work (W) in the equation is small, and is
generally ignored under most situations. The internal energy production
(metabolic rate) is determined by metabolic activity. The typical rate of
body heat production for an average male for different types of activity is
given in Table 5.1.
Due to presence of clothing the rate of conduction of heat from our
body slows down. The nature of the clothing influences the rate of heat
loss by conduction (Ck). The conduction heat loss is usually insignificant.
Also, the rate of change of heat stored in the body is neglected in a steadystate heat transfer with its environment. The exchange of heat is always
related in some way to the body surface area, irrespective of the fact
whether it is by radiation, convection or vaporisation.
The transfer of heat from the human body to the environment through
convection process is expressed as [16, 28, 29]
C = f cl ⋅ hc ⋅ (Tcl − Ta )

(5.3)

where f cl, clothing area factor (clo); hc, coefficient of convection heat
transfer (W/m2K); Tcl, clothing surface temperature (°C) and Ta, ambient
air temperature (°C).

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The heat transfer coefficient (hc) depends on the air velocity across the
body and also upon the position of the person and orientation to the air
current [25]. An approximate value of hc during forced convection can be
evaluated from the following empirical equation [27]
hc = 12.1⋅Va 0.5

(5.4)

where Va is the air velocity (m/s). The clothing area factor (fcl) can be
evaluated by the following empirical equation [30]:
f cl = 1.05 + 0.1 Icl

(5.5)

where Icl is the thermal insulation of clothing (clo).
The rate of heat transfer through clothing by radiation depends on the
mean temperature of surrounding environment, temperature of clothing
surface and characteristics of clothing and environment. The heat
transmission by radiation between the body and surrounding environment
can be expressed by the following empirical equation [16, 28, 29]:

)

4

4
R = σ ⋅ ε cl ⋅ f cl ⋅ Fvf ⎡(Tcl + 273.15 ) + (Tr + 273.15 ]
⎣

(5.6)

where s is the Stefan-Boltzmann constant, which has the numerical value
of 5.67×10–8 W/m2K4, ecl is emissivity of the clothing and Tr is radiant
temperature. The emissivity of the clothing and skin is very close to that
of a black body, and thus has a value of nearly 1. The effective area of the
body for radiation is consequently less than the total surface area, usually
about 75 percent of the total [25]. The effective area is determined with
the view factor between the body and surrounding surface (F vf). The
surrounding surface temperature is usually at a low temperature level. Thus
the temperatures of the surrounding surfaces can be taken as approximately
ambient air temperature [16].
Apart from all these mechanisms of heat loss from human body there
are other types of heat loss mechanisms which are not directly related to
clothing characteristics. These are heat loss due to respiration and heat
loss due to evaporation from skin. The heat loss due to respiration can be
divided into two components, namely evaporative heat loss (latent heat)
and sensible heat loss. The rate of heat loss by evaporation is the removal
of heat from the body by the evaporation of perspiration from the skin.
Evaporation always constitutes a rejection of heat from the body [25].
The evaporation loss is dependent upon the mass transfer coefficient and
the air humidity ratio for a given body surface temperature.

Thermal transmission

5.5.2

89

Heat exchange and Newton’s Law of cooling

Newton’s Law of Cooling states that the rate of change of the temperature
of an object is proportional to the difference between its own temperature
and the ambient temperature (i.e. the temperature of its surroundings).
Newton’s Law makes a statement about an instantaneous rate of change
of the temperature. It states that the rate of change of the temperature
(dT/dt) is proportional to the difference between the temperature of the
material (Tt) and the ambient temperature (Ta) [31]. This means that
dT / dt α (Tt – Ta)

(5.7)

Tt = Temperature of any material at time t.
T0 = Initial temperature
Ta = Ambient temperature
Clearly, if the material is hotter than the ambient temperature, i.e.
(Tt – Ta) > 0, then the material cools down, which means that the derivative
dT/dt should be negative. This means that the equation we need has to
have the following sign pattern,
dT / dt –k (Tt – Ta)

(5.8)

where k is a positive constant.
y(t)= Tt – Ta = Difference between material and ambient temperatures
at time t
y0 = T0 – Ta = Initial temperature difference at time t=0
Now, the derivative of y(t), and use the Newton’s law of cooling, we
arrive at
dy d
dT dTa dT
= (T (t ) − Ta ) =
−
=
= − k (T − Ta ) = − ky
dt dt
dt
dt
dt

(5.9)

The solution of the differential equation is:
y(t) = yoe–kt

(5.10)

Therefore,
T(t) – Ta = (To – Ta)e–kt

(5.11)

T(t) = Ta + (To – Ta)e–kt

(5.12)

or,

By rearranging the Newton’s equation for clothing assembly it becomes,

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Science in clothing comfort

(T– Tamb) = (T0 – Tamb)e–(1/RC)t

(5.13)

where T is the temperature of the body at a particular moment, T0 the
initial temperature of the body and Tamb the ambient temperature, t is the
cooling time (s). The cooling constant has the form [32]:

K1 =

1
1
=
R1C ( R0 + R) C

(5.14)

where C is the thermal capacity of the system (J/K), R1 is the thermal
resistance of both the fabric medium and the air medium around the fabric
sample (K/W), R is the thermal resistance of the fabric layer (K/W), R0 is
the thermal resistance of the air layer (K/W). The thermal resistance of
fabric could be calculated by the relation [32]:
R=

1
C

⎛ 1
1 ⎞
−
⎟
⎜
⎝ K1 K 0 ⎠

(5.15)

where K0 is the cooling constant of the system without fabric. Knowing
the thermal resistance as well as the fabric sample surface area S (m2) and
fabric thickness d (m), the fabric thermal conductivity λ (W/m K) can be
calculated as [32]:

λ=

1 d
×
R S

(5.16)

The thermal characteristics of fabrics are influenced by ambient
temperature. The heat transfer coefficient h (W/m 2 K), consisting of
conduction, convection and radiation mechanisms, is calculated by the
relation:
h=

1
dQ
×
S ΔT dt

(5.17)

where dQ/dt (W) is the measured heat transfer rate from the system through
the fabric to the ambient surroundings, S (m 2) is the area of the fabric
sample and ΔT (K) is the difference between the average temperature of
the system and the ambient temperature [32].
Newton’s cooling rate law is applied in order to evaluate the thermal
properties of textile fabrics. The procedure of thermal resistance
determination is based on Newton’s cooling rate law [32]:

91

Thermal transmission

1
dQ
Q =T = −
R
C
dt

(5.18)

where C (J/K) is the thermal capacity of the body, Q (J) is amount of heat,
T (K) is the temperature of the body, dQ/dt is the amount of heat passing
through the body per unit time and R (K/W) is the thermal resistance of
the body.

5.6

Transient heat flow and warm–cool touch of
fabrics

The transient heat conduction phenomenon is responsible for warm or
cool sensation when human skin touches another body. When skin comes
in contact with the clothing surface, which is normally at a lower
temperature than the skin surface, the heat flows away from the skin. Loss
of heat causes the temperature of the skin to fall, which is sensed by
thermoreceptors located within the skin’s dermal layer. The higher the
rate of the heat flow, the more rapid the temperature drops near the
thermoreceptors and the more intense is the feeling of coolness [5]. The
rate of change in temperature, resulting from heat flow from the skin to a
clothing material at a lower temperature when brought into contact with
it, is determined by the thermal inertia of the material. The thermal inertia
is the function of density, specific heat and thermal conductivity of material.
Any material that can absorb and conduct heat well will easily draw heat
away from the skin and feel cool, i.e. the higher the thermal inertia the
cooler it will feel to the touch. The fabric structural features, particularly
surface properties, have a great influence on cool–warm feel, and a threelayered model based on inner, middle and outer layers with different
thermal properties would be more appropriate.
The rates of change of skin temperature detected by the thermoreceptors
that determine warm or cool sensations varied quite significantly for
different types of fabrics. Typical values of rate of temperature changes
for warm and cool fabrics are shown in Fig. 5.3.
The maximum rate of heat flow occurs within about 0.2 s after an object
is touched, and this initial sensation is most important for the perception
of warmth or coolness to the touch. The coolness sensation is estimated
by measuring the initial rate of temperature change, the higher the initial
rate of temperature change higher will be coolness in touch. Figure 5.3
includes the measured responses of four fabrics, i.e. cool fabric; fabric
with smooth surface and two sides of the same fabric brushed; and warm
fabric. There were substantial differences in the rates of change of
temperature in all the fabrics. This suggests that sensations of warmth or

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Science in clothing comfort

5.3 Rate of change of skin temperature for different fabrics.

coolness to the touch are related to the surface properties of fabrics; in
this case, surface hairiness, in addition to the materials [33].
In addition to the fabric surface characteristics the type of materials
plays an important role in determining the fabric warm or cool feeling of
fabrics. Warm/cool feeling felt by man’s skin contacting an object is related
to the heat flow between man’s skin and the contacted object. It has been
reported that the maximum heat flux which is observed shortly after the
contact of the heated plate to fabric correlated well with warm/cool feeling
of human subjects to make it a convenient measure of warm/cool feeling
of fabrics. This maximum heat flux is named as qmax, as shown in Fig. 5.4.

5.4 Typical heat flux with respect of time.

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93

The qmax value was introduced as a measure of predicting warm/cool
feeling of fabrics by Kawabata and his team [34, 35], where qmax is the
peak value of heat flux which flows out of a copper plate having a finite
amount of heat into surface of fabric after the plate contacts the fabric
surface. At first, a theoretical prediction of qmax was given as transient
heat conduction within homogeneous body and the predicted qmax was
interpreted with respect to the effects of test condition and the thermal
properties of test specimen. The value qmax is a measure of warm/cool
feeling. It was found that warm/cool feeling correlates well with transient
heat conduction, especially with qmax, the peak value of heat flux which
arises for a very short time after the touching of the skin to the fabric
surface. The physical meaning of qmax is discussed on the basis of theoretical
analysis of transient heat conduction from outside object into human skin.
Figure 5.5 shows how the qmax of wide range of fabrics vary with moisture
content of fabrics. It is clear that for all the fabrics the qmax value increases
with the increase in moisture content, which means that the fabric feels
cool at higher moisture content. It is also clear that the linen fabric has
maximum qmax and wool fabric have minimum qmax up to certain level of
moisture content. This is the reason why linen feels cool and wool feels
warm when they are touched.
Kawabata and Akagi [34] reported the following experimental results
in regards to warm–cool feel of fabrics (qmax):
●

●

●

●

A high correlation was obtained between physically measured qmax
and fabric warm/cool feeing data gathered in human sensory tests.
A high qmax value corresponds to the cool feeling and a low qmax value
to warm feeling.
The value qmax depends on fabric surface condition and not on the
number of fabric layers or fabric thickness.
The value q max is sensitive to fabric water content and surface
geometry.

When skin is touched by an object whose temperature is lower than
skin, heat flows from the skin to the object, and it is considered that the
cool feeling arises from this short term transient heat conduction. The
heat conduction properties of materials have direct influence on qmax. The
heat conduction is an important parameter governing the transient heat
conduction (heat flux) after the contact with specimen. In other words, it
is the heat diffusion rate which dominates when heat flows from heat source
(e.g. human skin) to material. The heat diffusion rate depends on area of
contact, density of material, thermal conductivity, thermal diffusivity and
heat capacity [34]. When skin is touched by an object different in
temperature, the steady temperature distribution in skin is disturbed making
the thermoreceptor in skin to develop warm/cool signals.

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5.7

Measurement of thermal transmission
characteristics

The transmission of heat through a fabric occurs both by conduction
through the fibre and entrapped air and by radiation. The thermal
conductivity of the fabric is measured by the total heat transmitted through
fabric per unit time with unit temperature difference. The insulation value
of fabric is measured by its thermal resistance, which is the reciprocal of
thermal conductivity. In practice it is very difficult to measure the rate of
heat flow in a particular direction, as the heater dissipates heat in all
directions. Two methods are used to overcome this problem:
●
To compare with a sample with known thermal conductivity value
(Togmeter)
●
To reduce the heat loss (Guarded hot plate method)

5.7.1

Togmeter

Togmeter avoids the problem of measuring heat flow by placing a material
of known thermal resistance in series with the material under test so that
the heat flow is same through both materials [36]. The internal resistance
of test fabric can be calculated by comparing the temperature drop across
test fabric with the temperature drop across the standard material. There
are two methods of test that can be done with togmeter.
Two-plate togmeter
In this method the specimen under test is placed between heated lower
plate (standard) and an insulated upper plate as shown in Fig. 5.5. The
upper plate has low mass, so that it does not compress the fabric. The
temperature is measured at the heater (T1), between the standard and test
fabric (T2) and between the test fabric and upper plate (T3). The heater is
adjusted so that the temperature of the upper face of the standard is at skin
temperature (31–35°C). A small airflow is maintained over the apparatus.

5.5 Schematic diagram of two-plate togmeter.

Thermal transmission

95

Single-plate togmeter
In this method the specimen under test is placed on the heated lower plate
as above, but it is left uncovered as shown in Fig. 5.6. In place of top
plate, the air temperature (T3) is measured. The air above the test specimen
has a considerable thermal resistance itself so that the method is in fact
measuring the sum of the specimen and air thermal resistance. A separate
experiment is therefore performed without the specimen (i.e. a bare plate
test) to measure the resistance of the air Rair.

5.6 Schematic diagram of single-plate togmeter .

Rair = Rstand × (T2 – T3) / (T1 – T2),

(5.19)

where
R air = Thermal resistance of the air
R stand = Thermal resistance of the standard material.
To determine the sample resistance, the above experiment is repeated
with the sample placed on the bottom plate and the apparatus is again
allowed to reach the equilibrium.
The thermal resistance of the sample:
(Rsample) = Rstand × (T2 – T3) / (T1 – T2) – Rair

5.7.2

(5.20)

Guarded hot plate

In this method thermal transmittance of the fabric, which is the reciprocal
of the thermal resistance, is measured [37]. The apparatus consists of a
heated test plate surrounded by a guard ring and with a bottom plate
underneath as shown in Fig. 5.7. A constant temperature in the range of
human skin temperature (33–36°C) is maintained in all the plates. The
whole of the surroundings of the apparatus is maintained at fixed conditions
from 4.5 to 21.2°C temperature and 20 to 80% R.H. With test fabric in

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Science in clothing comfort

Top view

Side view

5.7 Schematic diagram of guarded hot plate.

place the instrument is allowed to reach the equilibrium. In this method
the amount of heat passing through the samples in watts per square meter
is measured from the power consumption of the test plate heater.
Combined transmittance of specimen and air, U1
U 1 = P/[A(TP – Ta)] W/(m2K)

(5.21)

where
TP and Ta are temperature of test plate and air, respectively
P = power loss from test plate (W)
A = area of the test plate (m2)
The bare plate transmittance Ubp is calculated similarly.
The intrinsic transmittance of the fabric alone, U2, is calculated as,
1/U 2 = 1/U 1 – 1/Ubp

(5.22)

The thermal resistance of the textile materials is measured in terms of
S.I. unit Km2/W. It is defined as the ratio of the temperature difference
between the two faces of the material to the rate of heat transfer per unit
area of the material to the faces. A practical unit of thermal resistance
widely used is Tog, which is one tenth of the S.I. unit. Another common
unit is Clo, approximately equal to 1.55 × Tog. It is defined as the resistance
of a clothing assembly which provides comfort to a sitting / resting subject
in a normally ventilated room.

5.7.3

KES-F Thermo Labo-II

It was developed for evaluating the thermal transmission characteristics
of textile fabrics [38]. This test is used to measure the power loss (Watt)

Thermal transmission

97

from BT-Box to the Water Box through the fabric samples. The sample is
kept on the Water Box at the room temperature (20°C). The temperatures
of the BT-Box and Guard are kept at 30°C. The amount of heat flowing
through the fabric sample per unit area (W/m2) is measured from the power
consumption of the test plate heater. The thermal conductivity (W/mK) of
fabrics can be calculated using the following equation [38, 39]:

Thermal conductivity ( k ) =

k =

Heat flow rate × distance
area × temperature difference

Q
L
×
t
A × ΔT

(5.23)

(5.24)

where, Q is the quantity of heat; t is time; L is the fabric thickness; A is
test area of fabrics and ΔT is temperature difference.
Alambeta instrument is used to measure thermal conductivity, thermal
resistance and thermal absorptivity values [40].

5.7.4

Thermal manikin

Thermal manikins are traditionally used by research institutes for climate
research. In recent years manikins are increasingly used in many practical
applications. Manikins are nowadays frequently used for testing and
product development by the building and the automobile industry for
evaluation of the performance of heating and ventilation systems. The
clothing industry uses manikins for development of clothing systems with
improved thermal properties. Test houses perform tests on protective
clothing according to specific international standards. This kind of work
results in continuous improvement of environments and products of
importance for comfort, health and safety in working life.
Thermal manikins are complex instruments for measurement of thermal
transmission behaviour of clothing in actual wear conditions. A humanshaped thermal manikin measures the heat losses due to conduction,
convection and radiation losses over the whole surface of the manikin
body and in all directions. Depending on number of individually regulated
body segments of the manikins surface the spatial resolution can be high.
The number of individually regulated segments can be even more than 30.
By summing up the area weighted values, a value for whole body heat
loss is determined. For the same exposure conditions, a thermal manikin
measures heat losses in a relevant, reliable and accurate way. The method
is quick and easily standardized and repeatable.

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Science in clothing comfort

The salient features of thermal manikins are as follows:
●

●
●

●

It can simulate the human body (the whole body and local) heat
exchange.
It can measure the 3-dimensional heat exchange from human body.
It can integrate the dry heat losses from human body in a realistic
manner.
It can measure the clothing thermal insulation objectively.

Thermal manikin such as the one shown in Fig. 5.8 provides a useful
and valuable complement to direct experiments with human subjects. In
situations where the heat exchange is complex and transient, the
measurements with a thermal manikin produce relevant, reliable and
accurate objective values for whole body as well as local heat exchange.
Such values are useful for:
●
●

●

●

●

evaluation of thermal stress in environments with human body,
determination of heat transfer and thermal properties of clothing
assemblies,
prediction of human responses to extreme or complex thermal
conditions,
validation of results from human experiments regarding thermal
stress, and
simulation of responses in humans exposed to thermal environments.

5.8 Photograph of thermal manikin.

Thermal transmission

5.8

99

Parameters for expressing thermal
characteristics

The thermal transmission characteristics of textile materials are expressed
by several parameters, namely Met, clo, tog, permeability index,
evaporative transmissibility, permeation efficiency factor, index of water
permeability. The main applications of all these parameters are mainly to
express the heat exchange between human body and its environment, and
for the prediction of the physiological variables under heat stress
conditions [41].

5.8.1

Met, Clo and tog

The heat exchange between human body and the environment can be
quantified in terms of Met and clo units [42, 43]. One Met is used to
quantify the metabolism of a man resting in a sitting position under
conditions of thermal comfort [42]. One Met is equivalent to 50 kcal/m2h
(i.e., 58.2 W/m 2). The term ‘clo’ is the measure of clothing insulation and
one clo is defined as the insulation of a clothing system that maintained a
sitting–resting average male comfortable in a normally ventilated room
(0.1 m/s air velocity) at the air temperature of 21°C and relative humidity
less than 50%. It is assumed that on an average 24% of the metabolic heat
is lost through evaporation from the skin and remaining 38 kcal/m2h should
be transmitted through the clothing assembly by conduction, convection
and radiation. The comfortable mean skin temperature is 33°C. The total
insulation of the clothing plus the ambient air layer is given by [41]:
It =

33 − 21
= 0.32 m 2 °C h/kcal
38

(5.25)

The insulation of air at the above specific condition is 0.14 m2 °C
h/kcal, the insulation of the clothing is found to be 0.18 m 2 °C h/kcal,
which is the difference between the total insulation of the clothing plus
the ambient air layer (i.e. 0.32 m2 °C h/kcal) and insulation of only the air
layer (0.14 m2 °C h/kcal). Thus, 1 clo unit is defined as 0.18 m2 °C h/kcal,
which is equal to 0.155 m2 °C/W [41]. This insulation of clothing is known
as effective insulation. A warm clothing assembly (business suit ensemble)
provides approximately 1 clo of insulation for the whole body [44].
Tog, a unit of thermal resistance, is defined as the thermal resistance
that is able to maintain a temperature gradient of 0.1 °C with a heat flux
of 1 W/m2 [45]. A light summer suit offers 1 tog insulation. When the
thermal insulation is expressed in terms of tog, the temperature drop
through clothing assembly can be calculated by one-tenth of the product

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Science in clothing comfort

of tog value and the heat flux. Also, the heat flux can be calculated by
dividing the temperature drop by one-tenth of the tog value, if the
temperature drop is known.

5.8.2

Permeability index

The permeability index developed by Woodcock [46] is an indicator of
the evaporative performance of clothing. The permeability index (i m) can
be expressed by the following equation:

im =

Rt
LR × Ret

(5.26)

where Rt is the total thermal resistance of the clothing plus surface air
layer (m2 °C/W), and Ret is the total evaporative resistance of the clothing
plus the air layer (m2 kPa/W). The ratio Rt/Ret represents the effectiveness
in transmitting evaporative heat as compared to the dry heat transmitted.
Lewis Relation (LR) is the ratio of evaporative mass transfer coefficient
to convective heat transfer coefficient. For typical applications it can be
treated as a constant equivalent to 16.65°C/kPa [47]. Theoretically the
value of permeability index ranges from 0 (i.e., completely water vapour
impermeable) to 1 (completely water vapour permeable). As the
permeability index is a dimensionless quantity, it offers the same value no
matter what unit is used.

5.9

Thermal transmission characteristics of fabrics

Thermal transmission characteristics of fabrics depend on various factors,
namely the morphological characteristics of component fibres, internal
structure of yarn and physical and structural characteristics of fabrics. The
thermal conductivity of textile fibres is dependent on various molecular
structural parameters, like molecular structure, density, crystallization level,
crystal orientation angle and mobility of molecular chains in amorphous
regions, etc. For example, the specific heat of cellulose is 1.25 kJ/kg K,
but the morphological structure of cellulose fibres, either natural or
regenerated, is responsible for their thermal capacity and thermal
conductivity of various cellulosic fibres. The thermal transmission
behaviour of textile fabrics is also influenced, to a great extent, by fibre
arrangement within yarns. The packing density of staple yarns varies widely
depending on the fibre arrangement. Irrespective of the production
techniques, textile fabrics are porous materials consisting of a solid matrix
with an interconnected void and the thermal transmission characteristics

Thermal transmission

101

depend on primarily on the porosity of fabrics. So, it is obvious that the
parameters which affect the fabric porosity also affect its thermal
transmission behaviour. As far as the geometrical characteristics of textile
fabrics are concerned the fabric thickness has the most significant influence
on thermal behaviour, explaining more than 90% of the phenomenon. This
is due to the fact that the increase in thickness of fabric affects the fabric
porosity due to the corresponding increases of fabric volume [32].
The thermal insulation characteristics of textile assemblies depend on
the randomness of fibre arrangement in fabrics. Fibre arrangement as well
as fabric thickness determines fabric insulation. Thus there seem to be
many individual and combined factors involving fibre, yarn, and fabric
characteristics and manner of applying fabric to the body which affect
human thermal, physical, and psychological comfort. Many of the effects
are so small that when coupled with the ability of the body to make
compensating physiological adjustments they are most difficult to isolate
and measure, either subjectively or objectively [48].
Yarn structural parameters influence the thermal transmission
characteristics of fabrics due to presence of air pockets within the yarn
body. The bulked yarns produced by shrinkage of one fibre component in
the yarn not only differ from other yarns in structure but also in their bulk,
mechanical and surface properties. The thermal transmission properties
of fabrics produced from these yarns are affected by the bulkiness of yarns.
The properties of fabrics made of bulked yarns are different from the normal
yarn fabrics in all respect. The bulking of yarn gives voluminous textile
product having good thermal insulating properties. In a study by Das et al.
[49] the bulked yarn fabrics show lower thermal conductivity than 100%
cotton fabric, which may be attributed to the very bulky structure of the
yarns working as an insulating medium. The entrapped air in the loose
fibrous assembly spaces does not allow heat of inner layer to transmit to
outer layer.
The structural modification of yarns can also be done by incorporating
additional micro-pores inside the yarn body in addition to the existing
micro-pores. This increases the porosity of the yarn and hence influences
the thermal characteristics of fabrics. The fabrics with micro-pores content
in the yarn have lower thermal conductivity as compared to 100% cotton
reference fabric sample. This is due to the fact that removal of PVA fibres
creates micro-pores within the yarn structure resulting in more entrapped
air. Since the air is a poor conductor of heat as compared to fibre, thus
resists transmission of heat through fabric [50].
The woven fabrics made out of staple twistless and hollow yarns have
great impact on the comfort related properties, i.e. air permeability, thermal
conductivity, percentage water vapour permeability, wicking and water

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absorbency. The fabric made of parent yarn (normal yarn) shows the
maximum thermal conductivity and fabric with hollow yarn shows
minimum thermal conductivity values (Fig. 5.9). The fabric with twistless
yarn shows intermediate thermal conductivity value. The minimum thermal
conductivity of fabric with hollow yarn is due to very bulky structure of
hollow fibrous assembly in weft works as an insulating medium. It entraps
air in the hollow spaces and does not allow heat of inner layer to transmit
to outer layer [51].

Thermal resistance (tog)

0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
Parent yarn

Twistless yarn

Hollow yarn

Type of yarn in fabric

5.9 Thermal resistance of fabrics made of speciality yarns.

It has been reported that as the yarns in knitted fabrics become finer the
thermal resistance and thermal conductivity decrease. In fact there is an
inverse relationship between thermal resistance and thermal conductivity
(R = h/λ; R is thermal resistance, h is fabric thickness and λ is thermal
conductivity). However, the study revealed that as the thermal resistance
decreases the thermal conductivity decreases as well. This contradiction
has been explained by the fabric thickness. When finer yarn was used in
fabric, yarn diameter and therefore fabric thickness was lower. If the amount
of decrease in thickness is more than the amount of decrease in thermal
conductivity, thermal resistance also decreases. Thermal absorptivity value
decreases while the yarn is getting finer. An increase in yarn twist
coefficient results in decrease in thermal resistance. This may be due to
the fact that as the twist coefficient increases the yarn becomes finer, as a
result the fabric thickness decreases [52].
The decrease in hairiness increases the surface area between the fabric and
skin; this causes cooler feeling. The thermal resistance of the fabrics made of
carded yarns is higher than the fabrics from combed yarns. This is due to the
fact that the fabrics produced from carded yarns have more hairiness. As the
yarn hairiness increase, the amount of static air that prevents the passage of
heat also increases. Another reason for this is fabric thickness [52].

Thermal transmission

103

With the increase in microclimate thickness the total heat flux from
human body decreases. This is due to increase in air layer which behaves
like an insulating material. The contribution of radiation in total heat flow
increases with the increase in microclimate thickness. This is due to the
fact that the heat transmission due to radiation is independent of
microclimate thickness. The lesser effect of fabric thickness variation
compared to the variation in microclimate thickness has been reported.
This is mainly due to the fact that the thermal conductivity of fabric is
more than the microclimate, and hence, the result is less sensitive to fabric
thickness than microclimate thickness. The effect of fabric thickness will
be larger when the thickness of microclimate is smaller [53].

References
1.
2.
3.
4.
5.
6.

7.
8.
9.
10.
11.
12.
13.

14.
15.

16.
17.

NIELSEN R .,

‘Work clothing’, Intl J Ind Ergonomics 7, 77–85, 1991.
Human Comfort, C.C. Thomas, Springfield, 1985.
GISOLFI C . V . and WENGER C . B ., ‘Temperature regulation during exercise: old
concepts, new ideas’, Exerc Sport Sci Rev 12, 339–372, 1984.
CABANAC M ., ‘Regulation and modulation in biology – A re-examination of
temperature regulation’, Ann NY Acad Sci 813, 21–31, 1997.
HENSEL H., Thermoreception and Temperature Regulation, Academic Press, New
York, 1981.
SENDOWSKI I ., SAVOUREY G ., BESNARD Y . and BITTEL J ., ‘Cold induced vasodilatation
and cardiovascular responses in humans during cold water immersion of various
upper limb areas’, Eur. J. Appl Physiol Occup Physiol 75, 471–477, 1997.
KING J ., ‘Thermoregulation: Physiological responses and adaptations to exercise
in hot and cold environments’, J. Hyperplasia Res 4(3), 2004.
KEIM S . M., GUISTO J . A . and SULLIVAN J . B ., ‘Environmental thermal stress’, Ann
Agric Environ Med 9, 1–15, 2002.
PUGH L ., ‘Cold stress and muscular exercise with special reference to accidental
hypothermia’, Br Med J 2, 333–337, 1967.
REULER J . B ., ‘Hypothermia. Pathophysiology, clinical settings and management’,
Ann Int Med 89, 519, 1978.
DUKES- DUBOS F . N ., ‘Hazards of heat exposure: a review’, Scand. J. Work Environ.
Health 7, 73–83, 1981.
http://www.cdc.gov/niosh/hhe/reports/pdfs/1986-0422-1891.pdf
LI Y., AIHUA M., RUOMEI W., XIAONAN L ., ZHONG W., WENBANG H ., LIYA Z . and YUBEI L .,
‘P-smart—a virtual system for clothing thermal functional design’, ComputerAided Design 38, 726–739, 2006.
FANGER P . O ., ‘Thermal environment-human requirements’, Sulzer Technical Rev
67, 3–6, 1985.
AIHUA M ., YI L ., XIAONAN L ., RUOMEI W. and SHUXIAO W ., ‘A CAD system for multistyle thermal functional design of clothing’, Computer-Aided Design 40, 916–
930, 2008.
TUĞRUL O . R ., ‘The effect of thermal insulation of clothing on human thermal
comfort’, Fibres & Textiles in Eastern Europe 15(2), 61, 2007.
BUTERA F . M ., ‘Principles of thermal comfort’, Renewable & Sustainable Energy
Reviews 2, 39–66, 1988.
SLATER K .,

104

Science in clothing comfort

18. http://en.wikipedia.org/wiki/Black_body
19. http://www.complore.com/black-body
20. http://en.wikipedia.org/wiki/Black_body#column-one
21. Thermoregulation, 2005. Harvard University, Division of Engineering and
Applied Sciences: web site, http://www.deas.harvard.edu/courses/es96/
spring1997/web_page/ health/thermreg.htm, 20.07.2005.
22. THRELKELD J . L ., Thermal Environmental Engineering, 2nd edition, PrenticeHall Inc., New Jersey, 1970.
23. LAYTON J . M ., ‘The science of clothing comfort’, Textile Progress 31(1/2), 2001.
24. Thermal comfort (2005a). Environmental Engineering Science 1, http://
www.esru.strath.ac.uk/Courseware/Class-16293/6-Comfort.pdf, 21.07.2005.
25. STOECKER W. F. and JONES J . W., Refrigeration and Air Conditioning, 2nd edition,
McGraw-Hill, Singapore, 1982.
26. OGULATA R. T., ‘The effect of garment on man’s thermal comfort’, Association
for the Advancement of Modeling & Simulation Techniques in Enterprises
70(1,2), 15–26, 2001.
27. ASHRAE Handbook of Fundamentals, American Society of Heating,
Refrigerating and Air-Conditioning Engineers, Inc, New York, 1977.
28. HAN T. and HUANG L., ‘A model for relating a thermal comfort scale to EHT
comfort index’, SAE Technical Paper Series, 2004.
29. ENGLISH M . J. M ., ‘Physical principles of heat transfer’, Current Anesthesia &
Critical Care 12, 66–71, 2001.
30. ASHRAE Handbook of Fundamentals, American Society of Heating,
Refrigerating and Air-Conditioning Engineers, Inc, New York, 1993.
31. http://www.ugrad.math.ubc.ca/coursedoc/math100/notes/diffeqs/cool.html.
32. SNEŽANA B STANKOVIĆ, DUŠAN POPOVIĆ and GORAN B POPARIĆ ‘Thermal properties of textile fabrics made of natural and regenerated cellulose fibers’, Polymer
Testing 27, 41–48, 2008.
33. SCHNEIDER A. M . and HOLCOMBE B. V., ‘Properties influencing coolness to the touch
of fabrics’, Text Res J 61, 488, 1991.
34. KAWABATA S . and AKAGI Y., J. Text. Mach. Soc. Japan 30, T13, 1977.
35. YONEDA M ., KAWABATA S., ‘Analysis of transient heat conduction in textiles and
its applications, Part II’, J Text. Mach. Soc. Japan 31, 73–81, 1983.
36. BS 4745 Method for the determination of thermal resistance of textiles.
37. ASTM D 1518 Thermal Transmittance of textile materials.
38. KAWABATA S. and NIWA M ., Modern Textile Characterization Methods, Marcel
Dekker, New York, 329–354, 1996.
39. YIP J . and NG S.-P., ‘Study of three-dimensional spacer fabrics: Physical and
mechanical properties’, J Matl Processing Tech 206, 359–364, 2008.
40. HES L., Thermal properties of nonwovens, in Proceedings of Congress Index 87,
Geneva, 1987.
41. HUANG J ., ‘Thermal parameters for assessing thermal properties of clothing’,
Journal of Thermal Biology 31, 461–466, 2006.
42. GAGGE A. P., BURTON A. C. and BAZETT H. C., ‘A practical system of units for the
description of heat exchange of man with his environment’, Science 94, 428–
430, 1941.
43. GOLDMAN R. F ., Thermal comfort factor: concepts and definitions, editors Hollies
N R S and Goldman R F. ‘Clothing comfort: interaction of thermal, ventilation,
construction and assessment factors’, Ann Arbor Science, 1977.

Thermal transmission
44.

45.
46.
47.
48.
49.
50.
51.

52.

53.

105

ASHRAE, ASHRAE Standard 55-1992 Thermal environmental conditions for
human occupancy. American Society of Heating, Refrigerating, and Air
Conditioning Engineers, Inc., Atlanta, 1992.
PEIRCE F . T . and REES W. H ., ‘The transmission of heat through textile fabrics’,
Part 2, J. Text Inst, T181–T204, 1946.
WOODCOCK A . H ., ‘Moisture transfer in textile systems’, Part 1, Text Res J 32,
628–633, 1962.
MCCULLOUGH E . A ., ‘Factors affecting the resistance to heat transfer provided by
clothing’, J Therm Biol 18, 405–407, 1993.
WERDEN J . E ., FAHNESTOCK M . K . and RUTH L ., ‘Thermal comfort of clothing of
varying fiber content’, Text Res J 29, 640–651, 1959.Galbraith
DAS A ., KOTHARI V . K . and BALAJI M., ‘Studies on cotton-acrylic bulked yarns and
fabrics: Part II – Fabric characteristics’, J. Text Inst 98, 363– 375, 2007.
DAS A ., ISHTIAQUE S . M . and SINGH R . P ., ‘Packing of micro-porous yarns. Part II
– Optimization of fabric characteristics’, J. Text Inst 100(3), 207–217, 2009.
DAS A . and ISHTIAQUE S . M ., ‘Comfort characteristics of fabrics containing twistless and hollow fibrous assemblies in weft’, Journal of Textile and Apparel,
Technology and Management 3(4), 1–7, 2004.
NILGÜN ÖZDIL , ARZU MARMARALI , SERAP DÖNMEZ KRETZSCHMAR , ‘Effect of yarn
properties on thermal comfort of knitted fabrics’, International Journal of
Thermal Sciences 46, 1318–1322, 2007.
MIN K ., SON Y ., KIM C ., LEE Y . and HONG K ., ‘Heat and moisture transfer from skin
to environment through fabrics: A mathematical model’, International Journal
of Heat and Mass Transfer 50, 5292–5304, 2007.

6
Moisture transmission

6.1

Introduction

Moisture transmission through textiles has a great influence on the thermophysiological comfort of the human body which is carried out through
perspiration both in vapour and liquid form. The clothing to be worn should
allow this perspiration to be transferred to the atmosphere in order to
maintain the thermal balance of the body. Diffusion, absorption–desorption
and convection of vapour perspiration along with wetting and wicking of
liquid perspiration play a significant role in maintaining thermophysiological comfort. The scientific understanding of the processes
involved in moisture transmission through textiles and the factors affecting
these processes are important to designing fabrics and clothing assemblies
with efficient moisture transfer in different environment and workload
conditions. The processes which play the major role in moisture
transmission in a particular situation are dependant on the moisture content
of the fabric, the type of material used, the perspiration rate and the
atmospheric conditions, such as humidity, temperature and wind speed.
In a regular atmospheric condition and during normal activity level, the
heat produced by the metabolism is liberated from body to atmosphere by
conduction, convection and radiation and body perspires in vapour form
to maintain the body temperature. At higher activity levels and/or at higher
atmospheric temperatures, the production of heat is very high, which
activates the sweat glands to produce liquid perspiration as well [1]. The
vapour form of perspiration is known as insensible perspiration and the
liquid form as sensible perspiration. When the perspiration is transferred
to the atmosphere, it carries out heat (latent as well as sensible) thus
reducing the body temperature. The fabric being worn should allow the
perspiration to pass through; otherwise it will result discomfort. The
perception of discomfort in the active case depends on the degree of skin
wetness. During sweating, if the clothing moisture transfer rate is slow,
the relative and absolute humidity levels of the clothing microclimate will
increase suppressing the evaporation of sweat. This will increase rectal
and skin temperatures, resulting in heat stress. It is also important to reduce
the degradation of thermal insulation caused by moisture build-up. If the

106

Moisture transmission

107

ratio of evaporated sweat and produced sweat is very low, moisture will
be accumulated in the inner layer of the fabric system, thus reducing the
thermal insulation of clothing [2] and causing unwanted loss in body heat.
Therefore, both in hot and cold weather and during normal and high activity
levels, moisture transmission through fabrics plays a major role in
maintaining the wearer’s body at comfort. Hence, a clear understanding
of the role of moisture transmission through clothing in relation to body
comfort is important [3]. The textile parameters which are affecting the
clothing’s moisture transmission properties should be identified to achieve
the required functionality of the clothing by engineering the fabric.
The concept of clothing comfort and the factors influencing the same
have been investigated by various researchers since 1930s till present date.
Researchers have worked to understand the effect of environmental
conditions on the moisture transmission properties of textile assemblies.
Moisture transmission through textile materials can be divided into two
basic principles, namely moisture vapour transmission and liquid water
transmission. The mechanisms involved in transmission of vapour and
liquid moisture through textile materials are quite different. Experimental
work has been conducted by number of researchers to determine the
influence of different material parameters, i.e., surface modification, fibre
and fabric finish, fibre type, thickness and porosity of the material as well
as ambient temperature and pressure on moisture vapour transmission
characteristic of textile materials [4–9]. The liquid moisture transmission
behaviour of a textile material is generally characterized by different
methods, namely horizontal wicking, transplanar or transverse wicking
and vertical wicking [10, 11]. The effects of different textile parameters,
namely yarn twist, yarn tension, fibre cross-sectional shape, spinning
technologies and texturing on the wicking behaviour of yarn have been
reported by different researchers [12–16].

6.2

Liquid water transfer: wicking and
water absorption

The transmission of moisture through textile materials in liquid form is
mainly due to the fibre–water molecular attraction at the surface of the
fibre materials, which is mainly determined by the surface tension and the
effective capillary pore distribution. Liquid transfer through a porous
structure involves two-stage process, i.e. initially wetting and then wicking
[17]. Wetting is the initial process involved in fluid spreading. In this
process the fibre–air interface is replaced with a fibre–liquid interface as
shown in Fig. 6.1(a) [18]. The forces acting at a solid–liquid boundary
under equilibrium are generally expressed by the following Young-Dupre
equation,

Moisture transmission

109

In sweating conditions, wicking is the most effective process to maintain
a feel of comfort. In the case of clothing with high wickability the moisture
coming from the skin spreads throughout the fabric offers a dry feeling,
and the spreading of the liquid enables moisture to evaporate quickly from
larger surface. When the liquid wets the fibres, it reaches the spaces
between the fibres and produces a capillary pressure. The liquid is forced
by this pressure and is dragged along the capillary due to the curvature of
the meniscus in the narrow confines of the pores as shown in the Fig.
6.1(b) [18]. The magnitude of the capillary pressure is given by the Laplace
equation:

P

2

cos
Rc

LV

(6.2)

where P is the capillary pressure developed in a capillary tube of radius
Rc. The difference in the capillary pressure in the pores causes the fluid to
spread in the media. Therefore a liquid that does not wet the fibres cannot
wick into the yarn or fabric [19]. The ability to sustain the capillary flow
is known as wickability [20]. The distance travelled by a liquid flowing
under capillary pressure, in horizontal capillaries, is given by the WashburnLukas equation:

L=

Rcγ cos θ 1 2
t
2η

(6.3)

Where, L is the capillary rise of the liquid in time t and η is the viscosity
of the liquid. The amount of water that wicks through the channel is directly
proportional to the pressure gradient. The capillary pressure increases as
both the surface tension in the solid–liquid interface and the capillary radius
decrease. A textile material consists of open capillaries, formed by the
fibre walls [21]. From the Washburn-Lukas equation, it is expected that
capillary rise at a specific time will be faster in a medium with larger pore
size. However, Miller [22], using a comparative wicking study, showed
that this is not always the case. He found that higher initial wicking through
the capillaries with bigger diameter has been overtaken with time by the
capillaries with smaller diameter. A larger amount of liquid mass can be
retained in larger pores but the distance of liquid advancement is limited.
This may be explained by the Laplace equation, as the radius of the capillary
decreases, the pressure generated in the capillary will be higher, causing
faster flow through the capillary. The model developed by Rajagopalan
and Aneja [23] also predicts that at a constant void area increasing the
perimeter of the filaments increases the maximum height attained by the
liquid. Conversely, increasing the void area at a constant perimeter

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decreases the final height attained but increases the initial rate of liquid
penetration.
With the increase in the packing coefficient of the yarn, the fibres come
closer to each other introducing a greater number of capillaries with smaller
diameter likely to promote liquid flow. In any system where capillarity causes
relative motion between a solid and a liquid, the shape of the solid surfaces
is an important factor, which governs the rate and direction of liquid flow
[24]. The shape of the fibres in an assembly changes the size and geometry
of the capillary spaces between the fibres and consequently the wicking
rate. With an increase in the non-roundness of a fibre, the specific area
increases, thus increasing the proportion of capillary wall that drags the
liquid. The tortuosity [25] of the pores has a great influence on the wicking
process. It depends on the alignment of the fibres as well as on irregularities
in the fibre diameter or shape along the pores. With the increase in the
tortuosity of the pores the wickability reduces [15, 16, 26]. For instance,
yarns spun with natural fibres have very irregular capillaries due to various
factors such as fibre roughness, cross-sectional shape and limited length,
which interrupt the flow along the length of the yarn. In the case of textured
filament yarns, as the number of loops in the yarn increases, the continuity
of the capillaries formed by the filaments decreases as the filament
arrangement becomes more random. Under these conditions wicking is
reduced. The same explanation is also applicable to the slower wicking found
in twisted yarns. During the spinning process, at higher twist levels, slow
migration of fibres takes place along the yam structure, changing the packing
density and resulting in disruption of the continuity, length and orientation
of the capillaries. The twist direction has no significant effect on the yarn
wicking performance. The presence of wrapper filament retards the wicking
as the volume of liquid in the capillaries reduces [13].
The density and geometry of fabric pores, which can be varied according
to woven fabric structure, has a significant influence on the liquid flow
pattern, both in the interstices and downstream. Darcy’s law is used to
describe a linear and slow steady state flow through a porous media and
is expressed by the following equation [18].
SV

SL

LV

cos

(6.4)

The rate of flow (Q) changes directly with the pressure head (ΔP) and
is inversely proportional to the length of the sample (L0) in the direction
of flow. K is the proportionality constant, known as the flow conductivity
of the porous medium with respect to the fluid. K is dependent on the
properties of the fluid and on the pore structure of the medium [27].
Hydraulic conductivity can be written more specifically in terms of
permeability and the properties of the fluids:

Moisture transmission

K=

k

η

111

(6.5)

where k is the permeability of the porous medium and is normally a
function of the pore structure and η is the viscosity of the liquid. Capillary
pressure and permeability are the two fundamental properties used to predict
the overall wicking performance of a fabric. The capillary pressure decreases
with an increase in the saturation as the pores fill with liquid and decreases
to zero for a completely saturated media. The permeability of the media
increases with an increase in the saturation, due to the higher cross-sectional
area of the absorbed water film to flow [28]. At low saturation level, smaller
pores in the media fill up first than larger pores. Wicking can not begin until
the moisture content is very high [29]. Initially the liquid spreading in a
fibrous material is facilitated by small, uniformly distributed and
interconnected pores. On the other hand, high liquid retention can be
achieved by having a large number of pores or a high total pore volume.
The dynamic surface wetness of fabrics is an important parameter influencing
the skin contact comfort in actual wear, as it is influenced by both the
collection and the passage of moisture along the fabric [30]. The dynamic
surface wetness of fabrics has been found to correlate with the skin contact
comfort in wear for a variety of types of fabrics, suggesting that the mobility
of thin films of condensed moisture is an important element of wearing
comfort. Under normal unstressed condition the perspiration of a resting
person amounts to about 15 g/m2h and under conditions of exertion or in a
hot environment, the perspiration increases to a value that may exceed 100
g/m2h. Perspiration rate increases with the level of activity. The higher
moisture collection by clothing after exercise, even in cold weather, creates
a surprisingly discomfort sensation due to the presence of a certain amount
of water in the skin clothing interface. Even very low moisture, as little as
3–5% moisture content in the garment, creates sufficient discomfort. Clothing
thermal insulation also decreases due to the moisture accumulation, and the
amount of reduction varies from 2 to 8%, as related to moisture collection
within the clothing assemblies [31]. Thus, in case of those activities where
production of sensible perspiration is very high, dynamic surface wetness is
a very important factor.
In the case of a cotton fabric, even though the moisture uptake from the
skin is high due to high moisture regain, the dynamic surface wetness is
not very good. Due to low capillarity the transfer of liquid moisture is not
spontaneous. It collects moisture in stead of flowing it out. As a result, it
creates a clammy feeling in high sweating condition. In the case of normal
polyester fibre fabrics, even though capillarity is good, due to poor
wettability they are not comfortable to wear. In the case of polyester

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microdenier fibre fabrics, the water up take is high and due to the high
number of capillaries a large amount of moisture can pass very quickly
through them to the atmosphere, thus providing a dry and comfortable
feeling to the wearer [18].

6.2.1

Evaluation of liquid water transfer

Wettability
The wettability of textile materials is tested to evaluate the wetting
performance. This can be measured by the following methods.
(i) Tensiometry – Tensiometer is an instrument used to measure the
wettability of the fabric by measuring the wetting force by Wilhelmy
method. In this method the wetting force (force applied by the surface,
when liquid comes in contact with the surface) is measured. The contact
angles are calculated indirectly from the wetting force when a solid is
brought in contact with the test liquid using Wilhelmy principle [11].
(ii) Goniometry – In this method the wettability of a material is measured
by measuring the contact angle between the liquid and the fabric by image
processing method [32]. Automated Contact Angle Tester (ASTM D 572599), HTHP contact angle tester, drop analyzer tester have been developed
based on this principle. Two processes are used, namely static wetting
angle measurement and dynamic wetting angle measurement [33]. The
dynamic contact angle is required as a boundary condition for modelling
problems in capillary hydrodynamics, including certain stages of the droplet
impact problem. The dynamic contact angle differs appreciably from the
static advancing or receding values, even at low velocities. The dynamic
contact angle can also be measured directly through low-power optics,
but it leads to manual error. The dynamic contact angle depends on the
spreading velocity of the contact line. To investigate the dynamic contact
angle of impacting liquid droplets, a series of experiments were conducted
by S¡ikalo et al. with individual droplets impacting onto dry and smooth
solid surfaces [34]. To observe the spreading of a droplet, high resolution
CCD camera (Sensicam PCO 1240 ×1024 pixels) equipped with a
magnifying zoom lens was used. The magnification can be manipulated
so that the image can accommodate the maximum spread of droplet [34].
Kamath et al. [35] have developed an apparatus to measure wettability of
filament specimen using liquid membrane technique. The force exerted
by the liquid membrane on the filament specimen as the ring with liquid
membrane moves up or down the filament specimen is measured in this
instrument, thus measures the wetting force. Manchester University
developed UMIST wettability tester which gives the idea of wettability as
well as initial wicking rate of the fabric.

Moisture transmission

113

Skin dynamic wetness is a very important factor determining the contact
comfort feeling of the skin. Clothing vapour resistance has been related
with skin wetness and metabolic rate by the following equation [36]:
w=

E sw
E max + 0.06

(6.6)

where Esw is the regulatory sweat evaporation rate, Emax is the maximal
evaporation rate possible in the ambient climate with the present clothing
and skin temperature for a totally wet skin and 0.06 being the minimal
skin wetness (or moisture evaporation) due to diffusion through the skin.
ISO 7730 is used to determine skin temperature, sweat rates and ambient
temperatures for comfort at various metabolic rates. In ISO 7730, required
sweat evaporation at comfort is given as a function of metabolic rate [37]:

(

)

E sw Wm −2 = 0.42 (M − 58)

(6.7)

where M is the metabolic rate and the sweat evaporation (W/m 2).
Scheurell et al. [30] have developed a technique to measure the fabric
dynamic wetness. In that method they made it possible to observe the
dynamic moisture change in the fabric by treating the fabric with cobaltous
chloride before the experiment and to observe the change in the colour
due to the absorption of moisture during the test.
The general terms and units used for measuring absorption of fabrics
are as follows:
(a) Bulk Material Absorption (BMA) (g g –1 ) – it records the total
absorption capacity of the fabric.
(b) Bulk Absorption Rate (BAR) (g g–1s–1) – it calculates the amount of
water absorbed vertically by 1 gm of fabric.
(c) Bulk Absorption Time (BAT) (s) – it records the time in seconds it
takes for the water to be absorbed vertically into the fabric.
Wicking
Liquid used for wicking test
The liquid which generally used for testing the wicking (for fabric comfort
evaluation purpose) of a fabric or yarn should represent close to human
sweat. Research suggests that for clothing physiology studies, the test
should employ with a liquid with surface energy properties similar to human
perspiration and heated to human skin temperature of around 35°C.
Literature says [38] that the principle electrolytes in sweat include sodium,
chloride (sodium chloride is table salt) and potassium, potassium chloride

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(is often marked as a table salt substitute). Most human sweat contains at
least 700 mg of sodium per liter, and probably averages around 1000 mg
of sodium per litre. In an experiment, conducted by Simile [39], saline
solution was produced using sodium chloride and water in order to simulate
sweat. Sodium chloride (NaCl) has an atomic mass of 58 g/mol with the
sodium atom occupying 40% of that mass; therefore, 1 g of sodium per
litre equals 2.5 g of NaCl per litre. Converting volume to millilitres, the
solution becomes 0.0025 g NaCl/ml or a 0.25% solution. This solution
was used in a horizontal-downward wicking test with a fabric sample (7 ×
1.5 cm). Comparing the results obtained by the perspiration simulant,
distilled water and tap water, using the same test method, it has been
observed that testing with distilled water can give a good indication of
how a fabric would act when in contact with liquid perspiration [39].
Hernett and Mehta also found very minor differences in their results
comparing heated human perspiration and distilled water [20].
Methods of measurement
After wetting of the fibre, when the liquid reaches in the capillary, a
pressure is developed which forces the liquid to wick along the capillary.
Capillary penetration of a liquid can occur from an infinite (unlimited) or
finite (limited) reservoir [40]. The different forms of wicking from an
infinite reservoir are transplanar or transverse wicking, in-plane wicking
and vertical or longitudinal wicking. A spot test is a form of wicking from
a limited reservoir [11]. In case of vertical capillary rise gravity acts to
slow down the flow rate before the equilibrium is reached [41], this
phenomenon is not there in case of in-plane wicking.
Different published standards propose wide range of test conditions for
evaluation of a particular parameter. For example, BS 3424:1996, Method
21, specifies a very long time period (24 hours) and is intended for coated
fabrics with very slow wicking properties. Whereas DIN 53924, 1978,
specifies much shorter time (5 minutes maximum) and is therefore more
relevant to the studies of clothing comfort involving the transfer of
perspiration.
The terms and units generally used for measuring wicking of fabrics
are as follows:
(a) Amount of Water Wicked (AWW) (g g–1) – it determines the wicking
capacity of the fabric away from the absorption zone.
(b) Surface–Water Transport Rate (SWTR) (gg–1s–1) – it calculates the
amount of water wicked by 1 g of fabric per second.
(c) Wicking Time (WT) (s) – it is the time in seconds for water to wick
across a specified distance (3.25 cm).

Moisture transmission

115

The terms spontaneous transplanar [40] or transverse wicking [3, 20]
are used when the transmission of a liquid is through the thickness of the
fabric, i.e. perpendicular to the plane of the fabric. Several techniques
have been developed to measure transplanar liquid transport into fabrics.
One of the test methods to measure the moisture accumulation associated
with the wicking of liquid moisture from sweating skin [42]. The apparatus
consists of a horizontal sintered glass plate kept moist by a water supply
whose height can be adjusted so as to keep the water level at the upper
surface of the plate. The specimen is placed onto the porous glass plate,
and the uptake of water is measured by timing the movement of the
meniscus along the long horizontal capillary tube. These tests have been
used as simulation of a sweating skin surface.
In case of in-plane wicking, the fabric surface stay in contact with the
wetting liquid at a point and from there liquid flows through the capillaries
along the fibre axis. An instrument has been developed by IIT Delhi in
order to measure in-plane wicking of the fabric (Fig. 6.2). The instrument
works on the siphonic principle and the water uptake by fabric sample
with time is recorded. The fabric sample is placed on a horizontal base
plate which is connected to the liquid reservoir by means of a siphon tube.
The fabric is covered by a glass top plate so as to ensure intimate contact
between the base plate and the fabric [43]. Similar instrument has been
developed by Adams and Rebenfeld [27] to measure the in-plane flow of
fluids in a fibrous mass, but they have used image analysis technique to
obtain the shape and position of a radially advancing fluid front, which
can define the directional permeability in the plane. There is a limitation
with this type of instrument due to the use of the upper plate. The possibility
arises that air bubble might be trapped in the fabric or between the plates
and fabric, as there is no other path for the air bubble to escape other than
the edges of the fabric. This could introduce an uncontrollable error.
Another source of error with this method is that as the plates, both bottom
as well as top, stay in contact of the fabric two extra capillaries are formed.
One is between the bottom plate and the fabric and another one is between
the fabric and the top plate. As a result it does not become possible to get
actual wicking of the fabric.
The alternative method of measuring the transverse wicking
characteristics of fabrics is shown in Fig. 6.3. In this method also the
transmission of water happens through the thickness of the fabric, i.e.
perpendicular to the plane of fabric. In this test the fabric sample is placed
on the top of the moist glass plate as shown in the Fig. 6.3. The sintered
glass plate can draw water depending on the wicking power. The water
level should just touch the bottom surface of the fabric, but not flood it.
The rate of water absorption is measured by the movement of the meniscus
along the long horizontal capillary tube.

Moisture transmission

117

been mounted above the plate to record the spreading of the liquid. This
instrument is placed on a compression load cell and is connected to the
bottom of a plate using a plastic tube. This instrument replaces the
electronic controls with an A/D interface card and appropriate software,
which automatically maintains the platform height at the same level,
maintaining a constant pressure head for the testing. They have developed
new types of plates to eliminate the extra capillaries and determine intrinsic
wicking ability of the fabric. In the middle of the plate there is a cylinder
where the liquid enters the system and that is the initial point of absorption/
wicking and is also the only point at which the fabric is touching the plate.
Liquid spreading distribution was determined by analyzing the image
captured by attached camera.
Several techniques have been developed for measurement of vertical
wicking characteristics. In visual observation method the movement of
the liquid along the sample is observed (Fig. 6.4). Sample is hung from a
horizontal fabric hanging attachment and lowered vertically into a reservoir.
The sample comes into contact with the contents of the reservoir at a
perpendicular direction. A little amount of dye is added in the water, which
can enhance the clear observation of the liquid. The movement of the liquid,
in terms of height wicked by the water, is measured with time. Microscopic
observation has also been used by some researchers [25, 46, 47]. A certain
amount of load should be hung at the lower end of the sample to keep it
straight.

Scale

Fabric

Clamp

Reservoir
6.4 Fabric vertical wicking tester.

Ansari and Haghighat [48] have developed an apparatus to study water
transport behaviour along yarn, using electrical resistance technique. This
technique is based on the phenomenon of the difference in electrical

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conductivity of air and water. Electrical conductivity of water is 18 times
that of air; so as the liquid wicks along the sample, electrical resistance
get reduced. The rise of the liquid water in the sample triggered an electrical
circuit which was coupled with a personal computer, so the distance of
rise as a function of time is determined. Electrical resistance technique
for fabrics was applied by many other authors as well [16, 49]. Hu et al.
[50] have developed a moisture management tester to characterize fabric
liquid moisture management properties, based on the same principle. So
measuring the electrical resistance of the fabric by this tester, it has been
correlated with the fabric moisture content. Ten indices have been
introduced to characterize the liquid moisture transmission. This method
is also used to measure the liquid water transfer in one step in a fabric in
multi-direction, as the liquid moisture spreads on both surface of the fabric
and transfer from one surface to the opposite.
Water transport along textile fibres has also been studied by various
scientists using electrical capacitance technique. Ito and Muraoka [12]
have developed an apparatus based on the electrical capacitance technique.
Similar apparatus was also developed by Tagaya et al. [51]. The dielectric
constant of water is 80 times more than that of air, so the water transport
can be accurately detected by measuring the change in electrical
capacitance between the condensers. The electric current generated by
the change in electric capacitance, which is caused by the transport of
water, is converted into voltage by a current to voltage converter circuit.

6.3 Principles of moisture vapour transfer
The moisture vapour transmission property of a fabric is essentially
governed by inter-yarn or inter-fibre spaces. The vapour diffuses through
the air spaces between the fibrous materials. The relatively open fabric
structure promotes the diffusion process. From Fig. 6.4 it can be observed
that during the diffusion of moisture vapour through textiles materials the
resistance to the moisture vapour diffusion comes in different layers. These
different layers are (i) evaporating fluid layer (which remains full of water
saturated vapour), (ii) confined air layer (between the skin and fabric),
(iii) boundary air layer, and (iv) ambient air layer. Moisture vapour
resistance mainly depends on the air permeability of the fabric and
represents its ability to transfer the perspiration coming out of the human
skin. The resistance provided by the fabric is lower than that of the external
boundary layer and often much lower than the inner confined air layer
between skin and fabric.

Moisture transmission

119

Ambient air layer
Boundary air layer
Fabric layer
Evaporating fluid layer
Human skin
6.5 Different layers through which moisture vapour transports.

Moisture in vapour form transmit through textile materials by the
following mechanisms:
●

●

●
●

Diffusion of the water vapour through the air spaces between the
fibres.
Absorption, transmission and desorption of the water vapour by the
fibres.
Adsorption and migration of the water vapour along the fibre surface.
Transmission of water vapour by forced convection.

6.3.1

Diffusion

In the diffusion process, the vapour pressure gradient acts as the driving
force in the transmission of moisture from one side of a textile layer to the
other. The diffusion of moisture vapour through the fibrous assembly is a
mass transfer phenomenon which occurs on a molecular level at lower
speed. The moisture vapour is transported from the higher concentration
zone to the lower concentration zone. Fick’s law [52] proposed the relation
between the flux of the diffusing substance and the concentration gradient
with the help of following relationship:

J Ax = DAB

dC A
dx

(6.8)

Where, JAx is the rate of moisture flux; dCA/dx is the concentration
gradient; and D AB is the diffusion coefficient or mass diffusivity of one
component diffusing through another media. The diffusion which follows
Fick’s law is called Fickian diffusion. In this case the diffusion coefficient
does not alter with the changes in the moisture vapour concentration within
the material or with the changes in temperature. In case of air permeable
fabrics and micro-porous polymers this type of diffusion takes place. The
diffusion which does not follow this law is called non-Fickian diffusion.

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Hydrophilic polymers transfer water vapour according to non-Fickian
diffusion. The water vapour transmission rate of the hydrophilic polymers
conforms to the following relationship:

WVT = DS

( p1 − p2 ) / l

(6.9)

where, (p1 - p2) = partial pressure gradient between the two surfaces;
l = thickness of the polymer; D = diffusion constant; and S = solubility
coefficient.
Moisture vapour can diffuse through a textile medium by two principles,
namely simple diffusion through the air spaces within the fibrous structure
and diffusion along the fibre itself [53, 54]. In the case of diffusion along
the fibre, moisture vapour diffuses from one surface of the fabric to the
surface of fibre and then travels along the interior of the fibres and its
surface and finally reaches the other surface of fabric. At a specific
concentration gradient the diffusion rate along the textile material depends
on the porosity of the material and also on the water vapour diffusivity of
the fibre. The diffusion coefficient of water vapour through air is 0.239
cm 2s –1 and through cotton fabric is around 10–7 cm 2 s –1. The moisture
diffusion through the air portion of the fabric is almost instantaneous
whereas through a fabric system it is limited by the rate at which moisture
can diffuse into and out of the fibres, which is due to the lower moisture
diffusivity of the textile material [55]. In the case of hydrophilic fibre
assemblies, vapour diffusion does not obey Fick’s law. It is governed by a
non-Fickian, anomalous diffusion [56, 57]. In this case the diffusion process
completes in two stages. The first stage corresponds to Fickian diffusion
but the second stage is much slower which follows an exponential
relationship between the concentration gradient and the vapour flux
[58–60]. This diffusion process can be explained by swelling of the fibres.
Due to the affinity of the hydrophilic fibre molecules to water vapour, as
it diffuses through the fibrous system, it is absorbed by the fibres causing
fibre swelling and reducing the size of the air spaces, thus delaying the
diffusion process [61]. According to Li et al. [62] this phenomenon is
mainly due to the fact that the heat of sorption, produced during absorption
of moisture vapour, increases the temperature of the fibrous assemblies,
which in turn affects the rate of moisture transmission. The moisture
diffusivity of a textile material is influenced by a number of factors. It
decreases with an increase in the fibre volume fraction of the material.
With the increase in fibre volume fraction the proportion of air within the
fibrous assembly decreases, this in turn reduces the total diffusivity. The
moisture diffusivity through the fabric decreases with an increase in the
flatness of the fibre cross-section [63]. With an increase in fabric thickness,
the porosity of the material is reduced, thus reducing the diffusion rate.

Moisture transmission

121

Water vapour diffusion is directly correlated with the air permeability of
the fabric. As the fabric porosity increases the air permeability increases,
which also results in higher moisture transmission through the air spaces
within the fabric. The type of finish applied (i.e. hydrophilic or
hydrophobic) to a fabric surface has no significant effect on the diffusion
process [4]. The diffusion co-efficient of moisture vapour in air can be
given as a function of temperature and pressure by the following
equation [64]:
2

⎡θ ⎤ ⎡P ⎤
D = 2.20 ×10 ⎢ ⎥ ⎢ 0 ⎥
⎣θ0 ⎦ ⎣ P ⎦
−5

(6.10)

where D is the diffusion co-efficient of water vapour in air (m2/sec), θ
is the absolute temperature (K), θ0 is the standard temperature of 273.15
K, P is the atmospheric pressure and P0 is the standard pressure (bar). In
general, the diffusion co-efficient of fibres increases with the increase in
the concentration of water in the fibres; an exception to this behaviour is
shown by polypropylene due to its hydrophobicity [56]. The water vapour
transmission through fabrics increases with the increase in the moisture
content and in the condensation of moisture vapour within the fabric [28].

6.3.2

Sorption–desorption

Sorption–desorption is an important phenomenon of moisture vapour
transmission which is responsible for maintaining the microclimate during
transient conditions. The hygroscopic fibrous materials absorb moisture
from the humid air close to it and release this absorbed moisture in dry air.
This process enhances the transmission of moisture vapour from the human
skin to the environment. The transmission of moisture vapour in case of
hygroscopic materials is higher than materials which do not absorb moisture
and thus reduce the moisture built up in the microclimate [65, 66]. During
absorption–desorption process the absorbing fabric works as a moisture
source to the atmosphere [67]. It also works as a buffer by maintaining a
constant vapour concentration in the air immediately surrounding it, i.e. a
constant humidity is maintained in the adjoining air, though temperature
changes due to the heat of sorption. Adsorption of water molecules takes
place below a critical temperature, due to the van der Waal’s forces between
the moisture vapour molecules and the solid surface of the textile materials.
The higher the vapour pressure and the lower the temperature, the higher
is the amount absorbed [65]. The amount of moisture vapour absorbed by
the textile materials depends on the moisture regain of the fibre and the
relative humidity of the atmosphere. In the case of hygroscopic fibres (e.g.

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cotton, viscose, wool) the moisture sorption is dependent not only on the
moisture regain and environmental humidity, but also on the phenomena
associated with sorption hysteresis, temperature, dimensional changes,
elastic recovery, swelling of the fibres etc. When fibre absorbs moisture
the fibre macromolecules or microfibrils are normally pushed apart by the
absorbed water molecules and fibre swelling takes place. This reduces the
inter-fibre as well as inter-yarns pores, thus reduces the water vapour
transmission through the fabric. With the increase in fibre swelling the
capillary channels between the fibres get blocked which results lower
wicking. Moreover, the distortion caused by the fibre swelling results in
built up of internal stresses which affects the moisture sorption process.
The mechanical hysteresis of the fibres enhances the adsorption hysteresis
[10]. The adsorption hysteresis increases with the increase in the
hydrophilicity of fibre.

6.3.3

Forced convection

The transmission of moisture vapour that takes place while air is flowing
over a moisture layer is known as forced convection. The amount of
moisture transmission in this process is governed by the difference in
moisture concentration between the surrounding atmosphere and the source
of moisture vapour. The process is governed by the following equation [68]:

Qm = − A hm (Ca − Cα )

(6.11)

where Q m is the mass of moisture vapour transmitted by convection
through the fabric area of A along the direction of the flow, C a is the
moisture vapour concentration on the fabric surface and C α is the vapour
concentration in the air. The rate of moisture transmission can be
controlled by the difference in vapour concentration, (C a - C α), and the
convective mass transfer coefficient h m, which depends on the fluid
properties as well as on its velocity. In a windy atmosphere the convection
method plays a very significant role in transmitting moisture from the
skin to the atmosphere through clothing [69, 70]. Evaporation and
condensation also have significant effects on moisture vapour
transmission through porous textile materials. These depend on the
temperature and moisture distribution in porous textile materials during
the transmission of moisture vapour transmission [71]. During the
evaporation of body perspiration in liquid form the latent heat is taken
away from the body and the body cools down. The importance of
evaporative heat transfer in maintaining thermal balance becomes more
crucial with the increase in the surrounding atmospheric temperature. In
this case, due to the low temperature difference between the human body

Moisture transmission

123

and the environment the heat transmission through conduction and
convection reduces [72]. When a negative temperature gradient exists
between the skin and the environment, evaporative heat transfer becomes
the only way to cool down the body temperature. As the latent heat of
evaporation of water is vary large (about 2300 kJ/kg) a small amount of
evaporation of perspiration results in significant amount of heat flow
[73]. The presence of wind enhances the evaporative heat transfer due
to enhanced evaporation rate and results in additional cooling that is
desirable in periods of peak performance.

6.4

Condensation of moisture vapour

Condensation of moisture vapour is a direct result of a fabric being
saturated by liquid perspiration and it generally occurs within the fabric
whenever the local vapour pressure increases to saturation vapour pressure
at certain temperature [74]. Condensation normally occurs when the
atmospheric temperature is very low. When the relatively warmer and moist
air from the skin comes into contact with relatively cooler fabric surface,
the fabric surface works as a cold wall and condensation occurs. It has
been reported that condensation can occur at atmospheric temperatures
below 10°C [75]. In the case of water proof fabrics, where the water vapour
can diffuse from the skin to the fabric layer more easily than from the
fabric layer to the atmosphere, the chances of occurrence of condensation
is very high. In most of the cases the condensation of moisture vapour in
an initially dry porous fibrous material takes place in three stages. At the
first stage velocity, temperature and vapour concentration fields are
developed within the material and condensation begins. In the second stage,
the liquid content increases gradually, but it is still too low to move and
finally, as the liquid content increases further and goes beyond certain
threshold value, the pendulum-like drops of condensate coalesce and begin
to move under surface tension and gravity [76]. When the vapour
concentrations in both the surfaces of the fabric are at the saturation level,
condensation of moisture vapour occurs in the entire thickness of the fabric.
If the moisture vapour concentration at the two faces is below saturation
level at a specific atmospheric temperature, condensation occurs only over
certain region within the fabric. In this case, condensation of moisture
vapour occurs in the fabric, which forms a wet zone separated by two dry
zones [75, 76]. The proportion of the wet region increases with the increase
in condensation of moisture vapour. The progress of condensation process
of moisture vapour takes place mainly in the direction of the warmer side
rather than that of the cooler side [77].

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6.5

Evaluation of moisture vapour transmission

The measurement of moisture vapour transmission through fabrics is a slow
and somewhat delicate operation but can be carried out very effectively.
Following are the different standard methods used for determining the
moisture vapour transmission characteristics of textile materials.
(i) Evaporative dish method or control dish method (BS 7209);
(ii) Upright cup method or Gore cup method (ASTM E 96-66);
(iii) Inverted cup method and the desiccant inverted cup method
(ASTM F 2298);
(iv) The dynamic moisture permeable cell (ASTM F 2298); and
(v) The sweating guarded hot plate method, skin model (ISO 11092).
Different terms are used to express the moisture vapour transmission
characteristics of textile materials. Results obtained from different available
methods are not always comparable due to the different testing conditions
and the units of measurement. Following terms and related units are used
for expressing the moisture vapour permeability of the fabrics [28, 54, 77]:
●

●

●

●

The percentage water vapour permeability index, WVP (%), is used
in the evaporative disc method (BS 7209). This method uses water at
20°C and an atmospheric condition of 20 ± 2°C and 65 ± 2% relative
humidity. This standard is based on the control dish method
(CAN2-4.2-M77) and the Gore modified disc method (BPI 1.4).
The moisture vapour transmission rate (g/m2/Day) is used in the cup
method (ASTM E96-66).
The resistance to evaporative heat transfer, Ret (m2Pa/W), is used in
the sweating guarded hot plate (ISO 11092:1993, EN 31092). It is an
indirect method of measuring the vapour transmission property of a
fabric. In this test method, the experiment is carried out in an
isothermal condition at the standard atmospheric condition.
The resistance of equivalent standard still air (cm) is used in the
holographic visualization method. In this method it is possible to
measure the resistance offered by the fabric layer and the air layer
separately. The resistance of the fabric can be expressed in terms of
the standard still air (cm) providing the same vapour resistance.

The different methods used for determining the moisture vapour
transmission characteristics of textile materials are given below.

6.5.1

Evaporative dish method

In this method water vapour transmission rate through fabric is measured
according to BS 7209 standard (Fig. 6.6). This method works on the basis

Moisture transmission

125

of gravimetric measurement. The specimen under test is sealed over the
open mouth of a dish containing water and placed in the standard
atmosphere for testing. After a period of time the total system reaches to
equilibrium. The successive weighing of the dish is made and the rate of
water vapour transfer through the specimen is calculated. The steady state
water vapour permeability is measured in this method. The relative water
vapour permeability of the sample is calculated by comparing the result
with a reference fabric.

6.6 Moisture vapour permeability tester.

Water vapour permeability (WVP) = 24 M/A. t (g/ m 2/day); and
Relative water vapour permeability index (%) = (WVP)f × 100 / (WVP)r
where M is the loss in mass (g) of water vapour through the fabric
specimen, t is the time between weighing (h), A is the internal area of the
dish (m2), (WVP)f and (WVP)r are the water vapour permeability of the
test fabric and reference fabric, respectively.

6.5.2

Upright cup method

This method is similar to that of evaporative dish method. In this method
the water vapour transmission rate of fabric is measured according to
ASTM E 96-80 procedure B. A shallow cup is filled with 100 ml distilled
water and a circular sample with a diameter of 74 mm is mounted on the
cup by covering with a gasket and clamping into its position (Fig. 6.7).
The cup assembly is housed in an environmental chamber. The air
temperature in the chamber is set to 23°C, and the relative humidity is
controlled at 50%. The air velocity in the chamber is maintained at 2.8
m/s. The cup assembly is weighed to the nearest 0.001 g on a top loading
balance periodically throughout one day. The water vapour transmission
rate is calculated as,

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Science in clothing comfort

WVT =

24 × G
; g / m2 / 24h
A×T

(6.12)

where WVT = water vapour transmission rate (g/m 2/day); G = change
in mass (g), T = testing time (h); A = test area (m2).

6.7 Upright cup method.

6.5.3

Inverted cup test method

In this method the water vapour transmission rates of fabrics are measured
according to ASTM E96, Procedure BW. To prevent the water in the cup
from wetting the specimen in the inverted test, a piece of hydrophobic
PTFE membrane is used to seal over the mouth of the cup. The test
specimen is placed over the membrane. The cup assembly, as shown in
Fig. 6.8, is placed in an inverted position on the upper deck. The cup
assembly is weighed periodically throughout one day. The calculations
are the same as that for the upright cup test. The inverted cup method is
designed mainly for use with waterproof samples, because the fabrics which
allow the passage of liquid water may not be inverted as they will leak.

6.5.4

Desiccant inverted cup method

This method for measuring water vapour permeability of fabrics works as
per ISO 15496 2004 standard [78]. In this method water vapour
transmission rates of fabrics are measured in the same way as inverted
cup test method. Only difference is that in this method the cup used in this
method is partly filled with desiccant such as potassium acetate, calcium

Moisture transmission

127

6.8 Inverted cup method.

chloride, anhydrous CaSO4 or anhydrous MgClO4. The drying agent stays
in direct contact with fabric minimizing the path of water vapour. The
inverted cup is covered by the specimen and the specimen is covered by
another piece of waterproof and vapour permeable membrane. The inverted
cup along with specimen is immersed into the water bath filled with distilled
water with the help of specimen holder. The measuring cup initially is
weighed by means of a balance then inverted and inserted into the specimen
holder. After certain time (t), the measuring cup is removed and reweighed.
The water vapour permeability of the specimen is then calculated by using
the following equation:

WVT = t × ( w2 − w1 ) / a

(6.13)

Where WVT is water vapour transmission rate; w2 = mass of cup assembly
after test; w1 = mass of test cup assembly body before test; a = test area.

6.5.5

Sweating guarded hot plate method

The sweating guarded hot plate apparatus or “Hohenstein” skin model
[72, 80] is used to measure the thermophysiological comfort of clothing.
It works as per ISO 11092 standards. It simulates the moisture transport
through textiles and clothing assemblies when worn next to the human
skin. This model measures the water vapour resistance of the fabric by
measuring the evaporative heat loss in the steady state condition. The
temperature of the guarded hot plate is kept at 35°C (i.e. the temperature
of the human skin) and the standard atmospheric condition for testing (65%
R.H. and 20°C) is used. In this skin model, A is the test area; Pm is the
saturation water vapour partial pressure at the surface of the measuring
unit; Pa is the water vapour partial pressure of the air in the test chamber;

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Science in clothing comfort

H is the amount of heat supplied to the measuring unit; ΔH C is a correction
factor and Ret0 is the apparatus constant. The water vapour resistance of
the fabric (Ret) may be calculated as follows:

Ret =

6.5.6

A(Pm − Pa )
− Ret 0 (m 2Pa/ W)
H − ΔH c

(6.14)

The PERMETEST apparatus

This fast response measuring instrument (skin simulator) has been
developed by Hes [82] for the measurement of the water vapour
permeability of textile fabrics, garments, nonwoven webs and soft polymer
foils. It works on the principle of heat flux sensing, i.e. by measuring the
evaporative heat resistance. The temperature of the measuring head is
maintained at room temperature for isothermal conditions. The heat
supplied to maintain the temperature of the measuring head, from where
the supplied water gets evaporated, is measured. The heat supplied to
maintain a constant temperature with and without the fabric mounted on
the plate is measured. This instrument measures the relative water vapour
permeability (%) of the fabric in the steady state isothermal condition using
the following equation:
Relative water vapour permeability (%)
=

Heat lost when the fabric is placed on the measuring head
×100 (6.15)
Heat lost from the bare measuring head

The PERMETEST can be used according to both BS 7209 and ISO
9920 standards. If the ring above the measuring head is used, a separating
air layer will be created between the measuring head (simulated skin) and
the fabric layer, thus providing the measuring condition according to BS
7209. On the other hand, if the ring above the measuring head is not used,
the fabric will be in direct contact with the measuring head, i.e. according
to the conditions used for the ISO 9920 standard.

6.5.7

Moisture vapour transmission cell

This is a faster and more simplified method for measuring the water vapour
transmission behaviour of fabrics. In principle, the cell measures the
humidity generated under controlled conditions as a function of time. There
are two cells, namely lower and upper cells. The cells are separated by the
test specimen. The lower cell is partially filled with water and the upper
cell is almost dry at the start of the test. As the moisture vapour is

Moisture transmission

129

transmitted through the fabric sample the relative humidity of the upper
cell increases with the time. The change in humidity at a given time interval
represents the moisture vapour transmission rate (T) of the fabric. The
standard relationship is,
⎛
1440
T = 269 × 10 − 7 ⎜⎜ Δ % RH ×
Time
Interval
⎝

(

6.5.8

)

⎞
⎟⎟ g/in2/day
⎠

(6.16)

Dynamic moisture permeable cell

The dynamic moisture permeable cell (DMPC) method is capable of
evaluating the moisture transmission properties of textiles under various
conditions, i.e. pure diffusion, combined diffusion and convection and
pure convection [69, 82]. The convective flow is evaluated by measuring
the relative pressure drop at the bottom outlet. The convective flow through
hygroscopic porous materials is complicated, due to the tendency of the
fibres to take up water vapour and experience fibre swelling. The change
in the fabric connective flow properties has been taken as a function of
relative humidity. The DMPC can be used to obtain both steady state and
dynamic state data.

6.5.9

Holographic bench technique

Holographic bench technique has been developed by Berger and Sari [83].
In this method the mass flow is measured with high accuracy using a microweighing technique. The resistance to the water vapour transfer depends
on the resistance of the air layer and the outer clothing. The resistance
offered by the fabric layer in vapour transmission from the skin to the
atmosphere is much lower than that offered by the external boundary air
layer and often much lower than that of the inner confined air layer between
the skin and the fabric. So, in order to measure the flow resistance of a
textile, one also needs a precise determination of the surrounded air layers.
Holographic bench technique separately measures the water vapour flow
resistance offered by different air layers; thus it provides the precise vapour
resistance value of the textile layer.

6.6

Moisture sensation in clothing

The moisture sensation of a clothing ensemble is the primary reason for
wearers’ dissatisfaction with the comfort properties of clothing. The
problem is intensified further for functional apparel because this sort of
clothing is frequently worn under stressful environmental conditions in

130

Science in clothing comfort

which moisture accumulates on the skin and within the clothing layers
and contributes to wearer discomfort. While efforts are being made in the
objective measurement of fabric moisture properties with the anticipation
of relating them to actual wearing conditions, there has been little
refinement of the subjective measurement of such factors. Moisture
sensation of clothing can be expressed either in terms of absolute threshold
or in terms of difference threshold.

6.6.1

Absolute threshold

The absolute threshold is defined as the minimum value of a physical
stimulus that will evoke a sensation. There may be some areas on the surface
of the body that are not as sensitive to moisture as others, and they may
differ greatly from person to person. The overall percentage of moisture
in clothing related it to sensations of comfort /discomfort, but the amount
of moisture that must accumulate in the first place before one even detects
has not been considered.

6.6.2

Difference threshold

The difference threshold is the minimum amount of stimulus change
required to produce a sensation difference, referred to as the just noticeable
difference on the psychological continuum. E. H. Weber, a 19th century
physiologist, determined that physical stimulus intensity must be increased
by a constant fraction of its starting value in order to be just noticeably
different. Weber’s law is written as

∆Φ/Φ = c

(6.17)

where Δ Φ is the change in stimulus intensity required to be just
noticeably different; c is a constant fraction of the starting stimulus
intensity. Weber’s prediction has been confirmed for a wide range of
stimulus intensities and sensory modalities and is shown to be an extremely
useful calculation providing an index of sensory discrimination that can
be compared across different conditions and modalities. Because of the
fact that the Weber’s fraction is a unit-less measure, it serves as an index
of sensory discrimination that can be compared across different conditions.
For evaluating the moisture sensitivity using different fabric stimuli, one
should compare the values of the Weber fractions to examine the effect of
fabric stimulus on moisture sensitivity. Weber’s fraction should only be
considered as an approximation of differential sensitivity; however, since
it increases dramatically at levels of stimulus intensities near the absolute
threshold.

Moisture transmission

131

It may be noted that the moisture sensation is only one of the many
sensations contributing to clothing comfort. Future investigations of
moisture sensation or other sensorial comfort variables could examine the
effects of various levels of these factors on subject sensitivity [84].

References
1.
2.
3.
4.
5.
6.
7.
8.
9.

10.
11.
12.
13.
14.
15.
16.

PARSONS K . C .,

Human Thermal Environments, Taylor & Francis Publishers,
Abingdon, 1993.
ZHANG P ., WATANABE Y ., KIM S . H ., TOKURA H . and GONG R . H ., ‘Thermoregulatory
responses to different moisture-transfer rates of clothing materials during
exercise’, J Text Inst 92(1), 372–378, 2001.
SAVILLE B . P ., Physical Testing of Textiles, Woodhead Publishing Limited,
Cambridge, 2000.
YASUDA T ., MIYAMA M . and YASUDA H ., ‘Dynamic water vapour and heat transport
through layered fabrics, Part I: Effect of surface modification’, Text Res J 61(10),
10–20, 1991.
YASUDA T ., MIYAMA M . and YASUDA H ., ‘Dynamic water vapour and heat transport
through layered fabrics, Part II: Effect of chemical nature of fibres’, Text Res J
62(4), 227–235, 1992.
YASUDA T ., MIYAMA M . and YASUDA H ., ‘Dynamic water vapour and heat transport
through layered fabrics, Part III: Surface temperature change’, Text Res J 64(8)
457–465, 1994.
LI Y . and LUO Z . X ., ‘Physical mechanisms of moisture diffusion into hygroscopic
fabrics during humidity transients’, J Text Inst 91(2) 302–316, 2000.
LI Y ., ZHU Q . and YEUNG K . W., ‘Influence of thickness and porosity on coupled
heat and liquid moisture transfer in porous textile’, Text Res J 72(5) 435–446,
2002.
FUKAZAWA T., KAWAMURA Y ., TOCHIHARA Y . and TAMURA T ., ‘Water vapour transport
through textiles and condensation in clothes at high altitudes – combined
influence of temperature and pressure simulating altitude’, Text Res J 73(8)
657–663, 2003.
CHATTERJEE P . K ., Absorbency, Elsevier Science Publishing Company, New Jersey,
1985.
PATNAIK A ., GHOSH A ., RENGASAMY R . S . and KOTHARI V . K ., ‘Wetting and wicking in
fibrous materials’, Text Progress38(1), 2006.
ITO H . and MURAOKA Y ., ‘Water transport along textile fibres as measured by an
electrical capacitance technique’, Text Res J 63(7) 414–420, 1993.
NYONI A . B . and BROOK D ., ‘Wicking mechanisms in yarns—the key to fabric
wicking performance’, J Text Inst 97(2) 119–128, 2006.
WANG N ., ZHA A . and WANG J ., ‘Study on the wicking property of polyester filament
yarns’, Fibers and Polymers 9(1) 97–100, 2008.
HOLLIES N . R . S ., KAESSINGER M . M. and BOGATY H ., ‘Water transport mechanisms
in textile materials. Part I: The role of yarn roughness in capillary-type
penetration’, Text Res J 26, 829–835, 1956.
HOLLIES N . R . S ., KAESSINGER M . M., WATSON B . S . and BOGATY H ., ‘Water transport
mechanisms in textiles materials. Part II: Capillary-type penetration in yarns
and fabrics’, Text Res J 27, 8–13, 1957.

132
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
31.
32.
33.

34.
35.
36.

37.

Science in clothing comfort
ZHU Q . and LI Y ., ‘Effects of pore size distribution and fiber diameter on the
coupled heat and liquid moisture transfer in porous textiles’, Intl J Heat and
Mass Trans 46, 5099–5111, 2003.
DAS B ., DAS A ., KOTHARI V . K ., FANGUEIRO R . and DE ARAUJO M ., ‘Moisture
transmission through textiles. Part I: Processes involved in moisture transmission
and the factors at play’, Autex Res J 7(2), 100–110, 2007.
WONG K . K ., TAO X . M ., YUEN C . W . M . and YEUNG K . W ., ‘Wicking properties of
linen treated with low temperature server’, Text Res J 71(1) 49–56, 2001.
HARNETT P . R . and MEHTA P . N ., ‘A survey and comparison of laboratory test
methods for measuring wicking’, Text Res J 54, 471–478, 1984.
MAO N . and RUSSELL S . J ., ‘Directional permeability in homogeneous non-woven
structures. Part I: The relationship between directional permeability and fibre
orientation’, J Text Inst 91(1), 235–258, 2000.
MILLER B ., ‘Critical evaluation of upward wicking tests’, Intl Nonwovens J 9,
35–40, 2000.
RAJAGOPALAN D. and ANEJA A . P., ‘Modelling capillary flow in complex geometries’,
Text Res J 71(9), 813–821, 2001.
MINOR F . M . and SCHWARTZ A . M ., ‘Pathways of capillary migration of liquids in
textile assemblies’, American Dyestuff Reporter 49, 37–42, 1960.
PERWUELZ A ., MONDON P . and CAZE C ., ‘Experimental study of capillary flow in
yarn’, Text Res J 70(4), 333–339, 2000.
ITO H . and MURAOKA Y ., ‘Water transport along textile fibres as measured by an
electrical capacitance technique’, Text Res J 63(7), 414–420, 1993.
ADAMS K . L . and REBENFELD L ., ‘In-plane flow of fluids in fabrics: Structure/flow
characterization’, Text Res J 57, 647–654, 1987.
GALI K., JONES B . and TRACY J ., ‘Experimental techniques for measuring parameters
describing wetting and wicking in fabrics’, Text Res J 64(2), 106–111, 1994.
ADLER M. M. and WALSH W. K., ‘Mechanism of transient moisture transport between
fabrics’, Text Res J 5, 334–343, 1984.
SCHEURELL D . M ., SPIVAK S . and HOLLIES N . R . S ., ‘Dynamic surface wetness of
fabric in relation to clothing comfort’, Text Res J 55, 394–399, 1985.
CHEN Y . S ., FAN J . and ZHANG W ., ‘Clothing thermal insulation during sweating’,
Text Res J 73(2), 152–157, 2003.
G R I N D S TA F F T . H ., ‘Simple apparatus and technique for contact-angle
measurements on small-denier single Fibres’, Text Res J 39(10), 958–962, 1969.
WEI Q . F ., Matheringham R. R. and Yang R. D., ‘Dynamic wetting of fibres
observed in an environmental scanning electron microscope’, Text Res J 73(6),
557–561, 2003.
SˇIKALO S., MARENGO M ., TROPEA C . and GANIC ´ E . N ., ‘Analysis of droplet impact on
horizontal surfaces’, Exp. Thermal Fluid Sci. 25, 503–510, 2002.
KAMATH Y . K ., DANSIZER C . J ., HORNBY S . and WEIGMANN H . D ., ‘Surface wettability
scanning of long filaments by a liquid membrane method’, Text Res J 57(4),
205–213, 1987.
HOLMÉR I ., Moisture permeation of clothing and thermal comfort, editors
BERGLUND B ., Tindvall T., Sundell J., Buildings, Ventilation and Thermal Climate,
Indoor Air, Vol. 5, Swedish Council for Building Research, Stockholm, 321–327,
1984.
HAVENITH G ., HOLME´ R I . and PARSON K ., ‘Personal factors in thermal comfort
assessment: clothing properties and metabolic heat production’, Energy and
Buildings 34, 581–591, 2002.

Moisture transmission
38.
39.
40.
41.
42.
43.
44.
45.
46.
47.
48.
49.
50.
51.
52.
53.
54.
55.
56.
57.
58.
59.

133

MCARDLE W., KATCH F ., KATCH V ., Exercise Physiology-Energy, Nutrition and
Human Performance, 4th edition, Williams and Wilkins, Baltimore, 1996.
SIMILE C . B., Critical evaluation of wicking in performance fabrics, Master thesis,
School of Polymer, Textile, and Fiber Engineering, Georgia Institute of
Technology, 2004.
KISSA E ., ‘Wetting and wicking’, Text Res J 66(10), 660–668, 1996.
D ´ SILVA A . P ., GREENHOOD C ., ANAND S . C ., HOLMES D . H . and WHATMOUGH N .,
‘Concurrent determination of absorption and wickability of fabrics: A new test
method’, J Text Inst 91(3), 383–396, 2000.
YOO S. and BARKER R. L ., ‘Comfort properties of heat-resistant protective workwear
in varying conditions of physical activity and environment. Part I: Thermophysical and Sensorial Properties of Fabrics’, Text Res J 75(7), 523–530, 2005.
CHATTOPADHYAY R . and CHAUHAN A ., ‘Wicking behavior of compact and ring spun
yarns and fabrics’, in One-day Seminar on Comfort in Textiles’, Indian Institute
of Technology, Delhi, 2004, October 16, 20–30.
MILLER B . and TYOMKIN I ., ‘Spontaneous transplaner uptake of liquids by fabric’,
Text Res J 54, 706–712, 1984.
KONOPKA A. and POURDEYHIMI B., ‘In-plane liquid distribution of nonwoven fabrics.
Part 1– Experimental observations’, INJ Winter 22–27, 2002.
SENGUPTA A . K . and SHREENIVASA MURTHY H . V ., ‘Wicking in ring spun vis-à-vis
rotor spun yarns’, Text Res J 55, 155–157, 1985.
NYONI A. B. and BROOK D., .Wicking mechanisms in yarns-the key to fabric wicking
performance’, Text Res J 97(2), 119–128, 2006.
ANSARI N . and HAGHIGHAT K ., ‘The wicking of water in yarn as measured by an
electrical resistance technique’, J Text Inst 91(3), 401–419, 2000.
KAMATH Y . K., HORNBY S., WEIGMAN H. D. and WILDE M. F ., ‘Wicking of spin finishes
and related liquids into continuous filament yarns’, Text Res J 64(1), 33–40, 1994.
HU J ., LI Y ., YEUNG A . K . W., WONG S . W . and XU W., ‘Moisture management tester:
A method to characterize fabric liquid moisture management properties’, Text
Res J 75(1), 57–62, 2005.
TAGAYA H ., HAIKATA J ., NAKATA K . and NISHIZAWA K ., ‘Measurement of capillary rise
in fabrics by electric capacitance method’, Sen-I Gakkaishi 47, 422–430, 1987.
SACHDEVA R . C ., Fundamentals of Engineering Heat and Mass Transfer, 2nd
edition, New Age International (P) Ltd., India, 2005.
FOHR J . P ., ‘Dynamic heat and water transfer through layered fabrics’, Text Res
J 72(1), 1–12, 2002.
LOMAX G . R ., ‘The design of waterproof, water vapour-permeable fabrics’,
J. Coated Fabrics 15(7), 40–49, 1985.
KOTHARI V . K ., Quality Control: Fabric Comfort, Indian Institute of Technology,
Delhi, 2000.
REN Y . J . and RUCKMAN J . E ., ‘Water vapour transfer in wet waterproof breathable
fabrics’, J Indus Text 32(3/1), 165–175, 2003.
MORTON W. E . and HEARLE J . W. S ., Physical Properties of Textile Fibres, Textile
Institute, Manchester, 1993.
NORDON P ., MACKAY B . H ., DOWNES J . G . and MCMAHON G . B ., ‘Sorption kinetics of
water vapour in wool fibres: Evaluation of diffusion coefficients and analysis
of integral sorption’, Text Res J 30, 761–770, 1960.
LI Y . and HOLCOMBE B . V ., ‘A two-stage sorption model of the coupled diffusion
of moisture and heat in wool fabrics’, Text Res J 62(4), 211–217, 1992.

134
60.
61.
62.
63.
64.
65.
66.
67.
68.
69.
70.
71.
72.
73.
74.
75.
76.
77.
78.
79.
80.

Science in clothing comfort
NORDON P .

and DAVID H. G., Int J Heat Mass Transfer 10, 1967.
‘Measuring the water vapor permeability of coated fabrics and
laminates’, J Coated Fabrics 25(4), 311–320, 1996.
LI Y ., HOLCOMBE B . V ., SCHEIDER A . M . and APCAR F ., ‘Mathematical modelling of
the coolness to the touch of hygroscopic fabrics’, J Text Inst 84(2), 267–273,
1993.
WOO S . S ., SHALEV I. and BARKER L ., ‘Heat and moisture transfer through nonwoven
fabrics. Part II: Moisture diffusivity’, Text Res J 64(4), 190–197, 1994.
JOST W., Diffusion in Solid, Liquids and Gases, Academic Press, New York,
1960.
BARNES J . C . and HOLCOMBE B . V ., ‘Moisture sorption and transport in clothing
during wear’, Text Res J 66(12), 777–786, 1996.
HONG K ., HOLLIES N . R . S . and SPIVAK S . M ., ‘Dynamic moisture vapour transfer
through textiles’, Text Res J 68(12), 697–706, 1988.
SUPRUN N ., ‘Dynamics of moisture vapour and liquid water transfer through
composite textile structures’, Int J Clothing Sci & Tech 15(3/4), 218–223, 2003.
INCROPERA F . P ., and DEWITT D . P ., Fundamentals of Heat of Mass Transfer, 4th
edition, John Wiley and Sons, New York, 1996.
GIBSON P ., KENDRICK C ., RIVIN D . and SICURANZA L ., ‘An automated water vapour
diffusion test method for fabrics, laminates and films’, J Coated Fabrics 24(4)
322–345, 1995.
GIBSON P . W. and CHARMCHI M., ‘Modelling convection/diffusion processes in
porous textiles with inclusion of humidity-dependent air permeability’, Int.
Comm. Heat Mass Transfer 24(5), 709–724, 1997.
LI Y . and ZHU Q ., ‘Simultaneous heat and moisture transfer with moisture sorption,
condensation and capillary liquid diffusion in porous textiles’, Text Res J 73(6),
515–524, 2003.
HAVENITH G ., HOLMER I., HARTOG E . A . D . and PARSONS K . C ., ‘Clothing evaporative
heat resistance – proposal for improved representation in standards and models’,
Ann Occup Hyg 43(5), 339–346, 1999.
SCHNEIDER A . M . and HOSCHKE B . N ., ‘Heat transfer through moist fabrics’, Text
Res J 62(2), 61–66, 1992.
RUCKMAN J . E ., ‘Analysis of simultaneous heat and water vapour transfer through
waterproof breathable fabrics’, J Coated Fabrics 26, 293–307, 1997.
HOLMER I ., ‘Protection against cold’, Textiles in Sport, editor Shishoo R.,
Woodhead Publishing Limited, Cambridge, 2005.
MURATA K ., ‘Heat and mass transfer with condensation in a fibrous insulation
slab bounded on one side by a cold surface’, Int J Heat Mass Transfer 17(38),
3253–3262, 1995.
REN Y . J . and RUCKMAN J . E ., ‘Condensation in three-layer waterproof breathable
fabrics for clothing’, Int J Clothing Sci and Tech 16(3), 335–347, 2004.
ISO 15496 2004 Textiles – Measurement of Water Vapour Permeability of
Textiles for the Purpose of Quality Control, International Organization for
Standardization, Geneva, Switzerland, 2004.
HUANG J . and QIAN X ., ‘Comparison of test methods for measuring water vapor
permeability of fabrics’, Text Res J 78, 342, 2008.
CONGALTON D ., ‘Heat and moisture transport through textiles and clothing
ensembles utilizing the “Hohenstein” skin model’, J Coated Fabrics 28(1), 183–
196, 1999.
PAUSE B .,

Moisture transmission
81.

135

HES L ., A new indirect method for fast evaluation of the surface moisture
absorptivity of engineered garments, Internet Conference on Engineered Textiles,
UMIST, Manchester, UK, 1998.
82. GIBSON P. W., ‘Water vapour transport and gas flow properties of textiles, polymer
membranes and fabric laminates’, J Coated Fabrics 28(4), 300–327, 1999.
83. BERGER X. and SARI H., ‘A new dynamic clothing model. Part 1: Heat and mass
transfers’, Int J Therm Sci 39, 673–683, 2000.
84. SWEENEY M . M . and BRANSON D. H., ‘Sensorial comfort. Part I: A psychophysical
method for assessing moisture sensation in clothing’, Text Res J 60, 371, 1990.

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7
Dynamic heat and mass transmission

7.1 Introduction
Dynamic transmissions of dry and wet heat are the important characteristics
of a clothing assembly to characterize its thermophysiological behaviour.
Each fabric layer is characterized by the two types of resistances, namely
the resistance to dry heat (insulation) and moisture vapour resistance. The
dry resistance is proportional to the thickness of the fabric layer, whereas
for moisture vapour permeability along with other parameters the
construction of the fabric layer is also important. Both for the insulation
and the moisture vapour permeability the thickness of the enclosed air layers
in an ensemble is of major importance. Insulation is increased more by a
non-moving air layer than by a textile layer. The moisture vapour permeability
is generally more dependent on the fabric parameters, but it decreases with
increasing thickness of air layers. When a person is in dynamic state the air
enclosed within the clothing also comes into dynamic state. This result in
disturbance in the thermal gradients by forced convective movements of air
through openings of clothing and the enclosed air transmits directly through
fabric layers to the environment. This air exchange reduces the insulation
and increases the moisture vapour permeability of the clothing ensemble
considerably. The final exchange of heat and moisture vapour is dependent
on level and pattern of activity and on the size of the openings. Wind and
physical movements decrease the insulating air layer sticking to the outside
surface of the clothing assembly. With large openings in the clothing structure
the wind penetrates into the clothing thus increases the heat loss. In strong
windy situation the high air velocity may compress the clothing and thus
reduce its insulation as the enclosed air layers are reduced. Insulation of
clothing also reduces if the clothing gets soaking wet with sweat or water.
The evaporative heat dissipation from wet clothing can be of significant
extent especially when the air velocity is high. Spencer-Smith [1] proposed
to quantify the wind induced reduction in thermal insulation of clothing by
a reduction factor, which was proportional to the wind velocity and the square
root of the fabric air permeability. The thermal insulation of a clothing

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137

ensemble can be estimated from the component garments and the fabric
thickness. In addition to the normal modes of heat transmission, namely
conduction, convection and radiation, the transmission of heat through the
clothing system involves the latent heat of various phase changes within
fibrous materials. The processes of transmission of heat and moisture vapour
are coupled by the exchange of the latent heat during the phase changes
such as evaporation or condensation, absorption or desorption and freeze or
melting. The thermal characteristics of clothing assemblies are largely
determined by these dynamic heat and moisture transfer processes. So,
dynamic heat and moisture transmission characteristics of clothing are
extremely important phenomena that control the thermophysiological
comfort of a person.
During high activity when a clothed person sweats, the sweat
accumulates within the clothing ensemble. After the person comes to the
resting state and the metabolic rate decreases, the body then does not need
evaporative cooling any more. At that time sweating stops, but the
evaporation of moisture from the clothing ensembles continues, which
provides unwanted cooling. This is the dynamic situation of heat and
moisture vapour transmission. The dynamic heat and moisture vapour
transmission characteristics of clothing cannot be expressed by the
parameters used for steady-state conditions.
The clothed human body is, in most of the time, under dynamic state,
i.e. it is subjected to changes in environmental variables, clothing and
levels of activity. Clothing, particularly those made from hygroscopic fiber,
e.g., cotton and wool, plays a major role during dynamic state. The heat
transmission between the body and the environment may be affected
significantly by the dynamic response of the clothing. Heat can bring
prevailing impact on clothing, when moisture is absorbed by the clothing.
This phenomenon is greatly affected by either the change of environmental
conditions or physiological changes in the body such as the metabolic
heat or rate of sweating.

7.2

Combined heat and moisture interactions with
textile materials

Moisture transmission through a textile material is not only associated with
the mass transmission processes, but the transmission of heat must also be
taken into account. Heat and moisture absorption in hygroscopic materials
are inseparably interrelated. During the transmission of water molecules
through textile materials, they are absorbed by fibre molecules due to their
chemical nature and structure. Absorption of water is followed by the
liberation of heat, known as heat of absorption. The amount of heat produced

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is dependant on the absorption capacity of the material. Due to the production
of heat, as the temperature is increased on the surface of the material, the
rate of moisture vapour transmission is reduced [2, 3, 4, 5]. During the
investigation of the wool-water system, Cassie et al [6] observed that in a
textile material, placed in a humid atmosphere, the time required for the
fibres to come to equilibrium with the atmosphere is negligible compared to
the time required for the dissipation of heat generated and absorbed by the
fibres when regain changes. With the increase in humidity, the heat transfer
efficiency of the material increases. The heat transfer process also comes
into play during the moisture transportation, under dynamic conditions, due
to phase change of the water molecules. Thus, during the transient stages of
moisture sorption and diffusion, the heat transfer process is coupled with
four different forms of moisture transfer due to the heat released or absorbed
during sorption/desorption and evaporation/condensation which in turn are
affected by the efficiency of heat transfer and the length of the transient
stage is dependant on the heat transfer process [7]. The coupling effect
between moisture diffusion and heat transfer depends on a number of
properties, such as the moisture of sorption capacities (isotherm), the fibre
diameter, the water vapour diffusion coefficient, the density and the heat of
sorption [8]. The heat of wetting of cellulosic fibres depends to some extent
on the moisture regain and the crystalline structure, and it decreases
proportionally with an increase in the degree of crystallinity of the fibres
[9]. Two transient phenomena, buffering and chilling, are associated with
the simultaneous heat and moisture vapour transport through fibre assemblies
[7]. The cooling effect or buffering effect is experienced due to perspiration
in hot climates and the chilling effect is associated with the after-exercise
sweating in cool climates. At a sudden increase in relative humidity in the
climate, fabrics absorb moisture maintaining a microclimatic condition and
generate heat. This gives rise to a thermostatic or buffering action for the
person wearing the fabric in clothing [10]. There would be a cooling effect
at the onset of perspiration in hot climates, whereas in the case of cold
climates it would result in a ‘post exercise chilling effect’ [11]. It reduces
the working performance, even causing hypothermia. When water vapour
(vapour perspiration) comes into contact with a cold wall (clothing) then it
condensates thus reduces the thermal insulation of clothing. Both these
phenomena are extremely dependent on atmospheric temperature and
humidity conditions.

7.2.1

Clothing thermal insulation during sweating

Clothing thermal insulation is an important parameter in thermal comfort.
It is used to determine the heat stress of a clothed person in a hot

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139

environment, which depends on the amount of moisture vapour evaporation
to maintain the thermal equilibrium of body, rate of body sweating and
skin wetness. It also depends on the extent of cold stress in a cold
environment. It is also an important measure of the effectiveness of clothing
functional design and suitability of clothing systems for specific end uses.
Heat transfer through clothing is an important topic related to thermal
comfort in environmental engineering and functional clothing design. The
total heat transmitted through clothing is commonly considered as the sum
of the dry heat transfer and the evaporative heat transfer.
The difference between clothing thermal insulation in non-perspiring
and perspiring conditions may cause errors when calculating dry heat loss
during perspiration, and consequently errors in evaporative heat loss and
measured water vapour resistance. It is generally believed that perspiration
reduces clothing thermal insulation as a result of greater effective thermal
conductivity, liquid water transport, and evaporation within wet clothing
assemblies. Total heat loss greatly increases with sweating due to
evaporative heat loss. Clothing thermal insulation decreases during
perspiration, and the amount of reduction varies from 2 to 8%, as related
to water accumulation within clothing ensembles [7].

7.2.2

Dampness

Moisture in clothing has been widely recognized as one of the most
important factors contributing to discomfort sensations. The skin wetness
contributes to the sensation of humidity, and that the sensation of dampness
is related to the amount of sweat accumulated in clothing. The subjective
sensations of skin and clothing wetness are considered as sensitive criteria
for evaluation of the thermal function of clothing. The moisture in clothing
contributes significantly to comfort perceptions during actual wear
conditions [12–15].
A chilling sensation is produced when damp fabrics are placed on the
specific part of the body, which is due to the temperature drop at the skin
in contact with the moist fabrics. Also, the temperature drop is influenced
significantly by the degree of the fabric skin contact that is associated
with fabric construction and surface hairiness. As fibre hygroscopicity is
a critical factor determining the coupled heat and moisture transfer
behaviour in fabric, it has a significant impact on the skin temperature
drop during the contact. Comparing fabrics with different degree of
hygroscopicity, the skin temperature drop increases with the level of excess
moisture as the degree of fibre hygroscopicity increases.
Ambient conditions, such as temperature and relative humidity, influence
the skin temperature drop significantly. The skin temperature drop

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decreases as ambient temperature increases, because of the decrease in
temperature difference prior to the contact. However, ambient temperature
has negligible influence on the differences of the skin temperature drop
among different types of fibres because ambient temperature mainly
influences the dry heat transfer process, not the moisture exchange process.
Ambient relative humidity, on the other hand, shows significant impact
on both the skin temperature drop of all fibres and the differences between
the fibres. When ambient relative humidity increases, the difference in
moisture concentration between the fabric and the environment decreases,
resulting in a smaller temperature gradient between the skin and fabric,
hence a smaller skin temperature drop during the skin–fabric contact. The
differences between various types of fibres are much greater when ambient
relative humidity is low. When the relative humidity approaches saturation,
the difference between fibres becomes negligible.

7.2.3 Clamminess and heat loss during high activity
The absorption of moisture by hygroscopic fibres in clothing releases heat,
which has significant impact on the heat balance and thermal perceptions
of wearer experiencing a sudden change from a warm and dry atmosphere
to a cold and humid environment. Hygroscopic fibres have the ability to
absorb a considerable amount of moisture from the surrounding
atmosphere. In transient humidity conditions, hygroscopic fibres can absorb
or desorb moisture from, or to, the surrounding environment, which can
delay the moisture change in the clothing microclimate. Theoretically, this
effect often acts as a buffer against sudden humidity changes in favour of
the wearer.
The moisture build-up at the inner fabric surface facing the sweating
skin is generally very slow in case of fabrics made of hydrophilic fibres
like cotton and the moisture build-up is very fast in case of fabrics made
of hydrophobic fibres like polyester. Figures 7.1 and 7.2 show the
accumulations of moisture within the microclimate region of fabrics made
of hydrophilic and hydrophobic fibres respectively.
It is evident from Figs. 7.1 and 7.2 that the moisture buffering by
hygroscopic fibres could be effective during a certain period after exercise.
The length of this buffering period and the magnitude of delay of humidity
rise depend on the ability of the fabric to remove moisture relative to the
speed of moisture build-up in the clothing microclimate, which is related
to ambient conditions, clothing material and style, and exercise intensity
of the subjects. Therefore, the apparent contradiction on clothing buffering
effect can be largely attributed to the differences in the climatic and exercise
condition used.

Dynamic heat and mass transmission
Release of heat

141

Sweat evaporation

Liquid
Moisture vapour

Clothing

Microclimate region

Metabolic heat

Body sweat
(liquid and vapour)

Human skin

7.1 Low moisture build-up in case of hydrophilic textiles.

Release of heat

Sweat evaporation

Liquid
Moisture vapour

Clothing

Microclimate region

Metabolic heat

Human skin
Body sweat
(liquid and vapour)

7.2 High moisture build-up in case of hydrophobic textiles.

By comparing fabrics with different level of hygroscopicity, the duration
of the transient behaviour depended strongly on the moisture sorption
capacity of the fabric. The moisture flux across an inert porous barrier can
reach a steady state within seconds, while non-steady condition may last
for more than an hour when a wool fabric is exposed to a humidity gradient.
During the transient period, the total amount of moisture removed from a
high humidity environment is greater with a highly hygroscopic fabric
such as cotton than with a weakly hygroscopic fabric such as polyester. In
comparing wool and polyamide clothing, the evaporation limit was reached
later when the subject wore a wool garment, and the perception of sweating
and clinging sensations were delayed. To study the effect of moisture

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absorbency of fibres in hot environment on the sweating rates of secondary
subjects, it was found that subjects wearing polyester lost greater amounts
of sweat, and the humidity in the microclimate was significantly higher
when wearing cotton [12].
Li and Holcombe [13] calculated the dry and evaporative heat fluxes
during exercise at the outer surface of the clothing by measuring the
temperature and moisture gradients. It can be observed from Fig. 7.3 that
there is no difference between dry and evaporative heat flux before
sweating. After sweating, the dry heat flux at the outer surface of the
garment was significantly higher when wearing wool than polyester. No
significant difference in evaporative heat flux was found between wool
and polyester.
Their results also indicated that fibre hygroscopicity has a significant
impact on the thermal response of the body and the heat balance of the
body–clothing system during the transient period of exercise. When
sweating starts, highly hygroscopic fibres absorb considerable amounts
of sweat and their temperature rises due to the heat of sorption released.
The elevated fabric temperature interacts with the body, stimulating higher
skin temperature and raising sweat rate. Some of the sweat is further
absorbed by the fabric, adding to the release of sorption heat and increasing
the dry heat loss at the outer surface of the garment. Hence, the body is
able to shed more heat during exercise. The sorption of moisture and the

Sweating starts

Wool
Heat flux (W/m2)

Polyester

Exercise time

7.3 Heat flux at the outer clothing surface during exercise. [12]

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143

released sorption heat by weakly hygroscopic fibres such as polyester are
very low. Most of the sweat in the garment was present as liquid and it had
a smaller influence on the dry heat loss at the outer surface of the garments.
Therefore, the role of clothing made from weakly hygroscopic fibres is
more passive and its enhancement of heat loss during exercise is smaller.

7.2.4 Buffering effect of clothing
The buffering effect of clothing made of hygroscopic materials has
significant impact on the thermal balance and comfort of the wearer during
the change in humidity due to environmental changes. Wearers frequently
experience various sudden and large changes in the external environmental
conditions. For instance, a wearer may be exposed to differences in
temperature and humidity greater than 10°C and 30% RH when walking
from an air-conditioned indoor environment to a hot and humid summer
outdoor environment. The difference in temperature between an airconditioned indoor environment and an outdoor winter environment in
the cold regions can be greater than 20°C. Clothing is an extremely
important barrier to protect the body against such sudden environmental
changes [12].
The magnitude of the buffering effect for a single-layer garment made
from wool and polyester was estimated by using a model simulating the
heat and moisture transport processes in clothing and their interaction with
the thermoregulatory system [14]. The temperature changes at the skin
surface, when a person wears wool or polyester garments in an ambient
temperature of 25°C and the RH varying from 30 to 90% and is suddenly
caught in the rain, were predicted. The skin temperature changes when
wearing wool were predicted to be smaller than those when wearing
polyester. Also, the difference in skin temperature changes between wool
and polyester decrease with increasing ambient relative humidity. These
predictions suggest that there are differences between wool and polyester
fibres in buffering against rain-chill, which represent the extremes of
hygroscopicity. For other textile fibres such as cotton and acrylic, whose
hygroscopicities fall between these extremes, the effectiveness of buffering
is expected to be related to the extent of their hygroscopicity. The more
hygroscopic the fibre, the stronger the buffering effect. When a subject
was wearing acrylic, the skin temperature decreased more than when he
was wearing wool. When wearing acrylic, the increase in humidity was
greater and faster than when wearing wool. These experimental results
confirmed the predictions that highly hygroscopic fibres such as wool could
buffer the body against sudden changes in temperature and humidity more
effectively [12].

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7.3

Factors affecting heat and mass transfer
through fabrics

The transmission of heat and moisture vapour through textile materials
is one of the major concerns in the design of high performance clothing
such as work wears, sports wears and military uniforms for extremely
cold or hot conditions. For better understanding of the heat and moisture
transmission behaviour of clothing systems, proper mechanisms for heat
and moisture transmission from skin to environment through the fabrics
need to be understand. Min et al. [16] concluded that the microclimate
plays the most significant role in the heat and moisture transfer from
skin to environment. Following are some of the important parameters
which affect the heat and moisture transmission characteristics of fabrics.

7.3.1

Yarn characteristics

In the studies conducted by Das et al. [17, 18], the bulking treatment of
ring spun cotton yarn reduces the thermal conductivity of fabrics as
compared to 100% cotton fabric, which may be attributed to very bulky
structure of the weft which works as an insulating medium. It entrapped
air in the loose fibrous assembly spaces and does not allow heat of inner
layer to transmit to outer layer. Moisture vapour transmission is an
important parameter in evaluating comfort characteristics of a fabric, as
it represents the ability to transfer perspiration coming out of the body.
The MVTR values of the bulked yarn fabrics are more than that of 100%
cotton fabric. Since yarn structure plays important role in transmission
of water vapour, the open structure of bulked yarn have better cover
factor which allows water vapour to transfer from inside to outside
through diffusion.
Similarly the fabrics produced from yarns with micro-pores within the
yarn structure show higher MVTR value than the reference fabric from
100% cotton normal yarn [19]. The increase in the moisture vapour
transmission rate with increase in the micro-pores is due to better exchange
of water molecules in vapour form between two faces of the fabric. The
micro-pores assist in transfer of water particles in vapour form from one
surface to the other surface by diffusion through them. The fabrics with
micro-pores content in the yarn have lower thermal conductivity as compare
to 100% cotton reference fabric sample [19]. This is due to the fact that
the micro-pores within the yarn structure entrap more air. Since the air is
a poor conductor of heat as compared to fibre, thus resists transmission of
heat through fabric.

Dynamic heat and mass transmission

7.3.2

145

Effect of environment temperature

It has been reported [16] that all the individual mechanisms of heat flux
(W/m2), i.e. total heat flux, conduction, radiation and moisture diffusion,
decrease with the increase in environment temperature, hence heat flux
decreases with the decrease in the driving force. In the case of fabric surface
temperatures, the inner surface is less sensitive than the outer surface.

7.3.3

Effect of microclimate thickness

The total heat flux and individual heat transfer mechanisms, moisture
fraction at the inner and outer fabric surfaces, and temperature at the inner
and outer surfaces of fabrics decrease with the increase in microclimate
thickness [16]. The decrease in heat flux is the result of increased air layer
which behaves like an insulating material. The contribution of radiation
increases with the increase in microclimate thickness, since radiation is
independent of microclimate thickness while the fabric surface temperature
is lowered.

7.3.4

Effect of fabric thickness

The total heat flux varies about 20% when fabric thickness changes from
0.5 to 5 mm [16]. The lower variation in total heat flux compared to the
variation in microclimate thickness is due to the fact that the thermal
conductivity of fabric is larger than the air layer between skin and clothing
(i.e. microclimate) and, hence, the result is less sensitive to fabric thickness
than microclimate thickness. The effect of fabric thickness is larger when
the thickness of microclimate is smaller.

7.3.5

Effect of layering of fabrics

Resistances offered by clothing during transmission of heat and moisture
vapour are two most important characteristics of clothing which control
the thermal comfort. Proper understanding of dynamic transmission
behaviour of these two clothing properties is very important during the
selection of clothing for specific end uses and designing of functional
clothing assemblies. Clothing can be of two types: tight-fitting inner
garment and a loose-fitting outer garment as shown in Fig. 7.4.
When a clothed person walks through a windy environment the loose
outer garment generally flaps, pumping out warm air and moisture vapour
from the air gap between the tight-fitting inner garment and the loosefitting outer garment and replacing it with cooler air from the surrounding
environment, and at the same time wind may penetrate through the pores

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7.4 Heat and mass transfer from human body covered with
tight-fit and loose-fit garments .

of outer garment to create dynamic heat and mass exchange. The actual
mechanism of dynamic heat and mass transfer through clothing system
is generally very complicated. In order to simplify the analysis under
steady state, one can consider the dry heat flow through clothing as
consisting of two parts: the first part is induced by conduction, convection
and radiation, and the other part induced by air ventilation and wind
penetration. Similarly the heat flow due to moisture evaporation can also
be regarded as consisting of two parts: the part induced by diffusion and
convection and the other part induced by air ventilation and wind
penetration [15]. It is evident from Fig. 7.4 that the entire dry heat (H dryt)
generated by human body transmits initially through the tight-fit inner
garment (H ig) and then divided into two components, i.e. heat flow without
mass transmission and heat flow with mass transmission, while
transmitting through the loose-fit outer garment. The heat flow without
mass transmission through tight-fit inner garment (H di) is governed by
conduction (H cn), convection (H cv) and radiation (H rad). The heat flow
with mass transmission is governed by moisture evaporation (H mev), i.e.

Dynamic heat and mass transmission

147

by air ventilation and/or wind penetration directly into the environment
[13]. The relationship is as follows:

H dryt = H ig = ( H di ) + ( H mev ) = H cn + H cv + H rad + H mev

(7.1)

Since the total dry heat transmitted through tight-fit inner garment (Hdi)
must transmit through the loose-fit outer garments and the outer surface
of the clothing ensemble, we have:
Hdi = Hdo = H dos

(7.2)

where H do is the dry heat loss through the outer garments and H dos is the
dry heat loss from the outer surface of clothing ensemble. The evaporative
heat loss by moisture transfer (H mev) must transmit through the outer
garments and the outer surface of the ensemble. The evaporative or latent
heat transfer through outer garments should be equal to the evaporative or
latent heat loss from the outer surface of the clothing ensemble. After
passing through the tight-fit inner garment, the total evaporative heat
generated by sweat evaporation is divided into two components:
evaporative heat loss through the outer garments (H evo) and evaporative
heat loss directly into the environment by air ventilation and/or wind
penetration (H veno). The relationship can be written as:
Hmev = Hevo = Hveno

(7.3)

The temperature of air gap between two layers of fabrics increases when
water vapour transmission takes place and the increase in temperature is
almost proportional to the water vapour absorption rate of the fabric [20].
The dynamic thermal response of different types of clothing ensemble is
predominantly governed by the moisture sorption and desorption in
hygroscopic fabrics [21]. The thermal parameters that describe the dynamic
response of fabrics due to the changes in physiological and environmental
conditions are more important than those under steady-state conditions.
Faster the vapour pressure build-up at the inner fabric surface as well as
in the microclimate, the stronger the discomfort sensations will occur.
Higher moisture vapour pressure at the inner fabric surface and
microclimate results in more intense sensation of discomfort. The surface
temperature of clothing changes during the dynamic transmission of
moisture vapour within the clothing. In case of hygroscopic fibres the
increase in the surface temperature is due to release of more heat from
moisture sorption. The more heat loss from the body during transient period,
the better the heat and moisture transfer property of the fabric [22].

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7.4

Evaluation of heat and mass transmission

The evaluation methods of combined heat and moisture comfort of clothing
are more complex than the testing methods for other properties of fabrics.
To evaluate the heat and moisture comfort of clothing ensemble, it is
required to consider human body, clothing, environment, and the other
factors. Three methods are available for evaluating the combined heat and
moisture comfort characteristics of clothing ensemble – microclimate
method, thermal manikin with sweating skin, and wear trial method [23].
Microclimate method is used to evaluate the heat and moisture comfort of
fabric, where as for thermal manikin with sweating skin clothing is required
and wear trial method is a subjective measurement. Thermal manikin with
sweating skin has been developed to present the human body. Manikin
acts as a heat and moisture transfer sensor that mimics a real threedimensional body. It senses the difficult-to-model local sweat evaporation,
convection and radiation processes that are highly dependent on local
microclimate. Manikin is also used to be clothed to accurately depict the
sweat transport of a clothed human and analyze other clothing effects. In
order to ascertain how perspiration or sweating affects clothing thermal
insulation with dry heat transfer, a special type of perspiring fabric,
covering the manikin surface to simulate the sweating skin, is used to
measure clothing thermal insulation when there is little perspiration and
when there is heavy perspiration. The skin of the manikin is generally
made of a strong, breathable (i.e., water proof, but moisture permeable)
fabric with completely sealed seams. It is filled with water to create a soft
body similar to a human body. Since the breathable fabric is permeable to
moisture vapour, gaseous “perspiration” can be simulated depending on
the breathability of the skin. The skin of manikin is generally designed
with a long zipper at the back, so it can be replaced after prolonged use or
interchanged with another skin made from fabric of different specifications.
The manikin is generally heated by heaters within the trunk, and its core
temperature is controlled approximately close to the body core temperature,
i.e. at 37°C. Water within the manikin is circulated by a pump and a piping
system, which distributes heat to the head, arms, and legs by pumping the
warm water to the extremities. The skin temperature distribution depends
on the output of the pump and the opening of the valves, which is preadjusted to an appropriate setting. Due to its design and construction, the
manikin is inexpensive, especially compared with other expensive sweating
manikins. Normally two types of manikins are available: sweating manikin
and dry manikin. Using dry manikin it is only possible to measure dry
heat flow both in transient and steady condition, whether using sweating
manikin it is possible to measure evaporated heat loss as well as dry heat
loss in transient and steady state conditions [24].

Dynamic heat and mass transmission

149

The thermal insulation of clothing and moisture vapour resistance can
be calculated by measuring the heat supply to the manikin, the temperature
and the humidity at the skin and environment, and the rate of perspiration.
The total thermal insulation (Rt), including the insulation of clothing and
surface air layer is given by [7]

Rt = ⎡⎣ As (Ts − Ta )⎤⎦ / ⎡⎣ H s + H p − H e ⎤⎦

(7.4)

where As is the total surface area of the manikin; T s is the mean skin
temperature; Ta is the mean temperature of the environment; H s is the heat
supplied to the manikin or generated by the heaters; Hp is the heat generated
by the pump (Hp is measured by determining the power supply to the pump);
and H e is the evaporative heat loss from water evaporation.
Evaporative heat loss is calculated by using the following equation [7]:
He = λQ

(7.5)

where l is the heat of evaporation of water at the skin temperature (the
typical value of l is 0.67 W.h/g at 34°C temperature; Q is the perspiration
rate or water loss per unit time, which can be measured by measuring the
water supply.
The total moisture vapour resistance (Ret), including the resistance of
clothing and the surface air layer, is calculated using the following
formula [7]:

Ret = ⎡⎣{As ( Ps − RH a Pa )} / H e ⎤⎦ − Res

(7.6)

where Ps is the saturated water vapour pressure at the skin temperature
(which is the water vapour pressure of the water film just inside the skin);
RHa is the relative humidity of the surrounding environment in a fraction;
Pa is the saturated water vapour pressure of the surrounding environment;
R es is the moisture vapour resistance of the skin (typical value is
3.3 m 2Pa/W).
Wang and Li [25] have developed a new method for measuring dynamic
fabric heat and moisture comfort. Normally the indices which are used to
characterize clothing and fabric comfort are Clo value, moisture
permeability index and evaporative cooling efficiency index. In their study
they have used microclimate method and calculated heat and moisture
ratio (HMR) and relative thermal diffusion ratio (RTDR) to evaluate the
heat and moisture transmitting property of the fabric. They have introduced
an advanced testing instrument, which can simulate both the latent and
apparent sweating states. Using this instrument they have found the

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relationship between the microenvironment and the dynamic heat and
moisture comfort of fabric and their characteristics.
PERMETEST [26] instrument is used to determine the relative water
vapour permeability as well as the thermal transmission characteristics.
The outer surface of the tested sample is exposed to a parallel air flow and
the other sample side faces a porous humid layer (0.2 ml of water are
injected into the layer), which simulates any underwear filled with liquid
sweat. A space of 1 mm between the sample and this layer separates the
liquid and vapour phase of the water. The working principle of the
instrument consists in measuring the dynamic heat flow caused by the
evaporation of water passing through the tested specimen. Relative water
vapour permeability is defined as the ratio of the heat loss measured with
sample and the heat loss measured without sample.
Along with water vapour resistance of the fabric (Hohenstein Skin
Model [27]), PERMETEST can also measure the dry heat transfer through
the fabric. Under the steady state condition it measures the thermal
resistance of the fabric by measuring the dry heat transfer to the guarded
hot plate through the fabric by the following equation:
Rt =

A(Tm − Ta )
− Ra 0 (m2K/W)
H − ΔH c

(7.7)

where, Ra is the thermal resistance of the fabric and Ra0 is the intrinsic
thermal resistance of the instrument. Tm and Ta are the temperatures of the
guarded plate and air consecutively.
The dry heat resistance Rt of the fabric is measured in PERMETEST by
measuring the difference between the heat flow with and without sample,

⎡ 1
1 ⎤
Rt = (T1 − T0 )× ⎢
−
⎥
⎣ S .u1 S .u 0 ⎦

(7.8)

T1, T0 are the temperatures with and without samples respectively; u1 and
u0 are output voltages with and without sample. S is the sensitivity of
instrument.
The sweating guarded hot plate simulates both heat and moisture vapour
transfer from the body surface through the clothing layers to the
environment. It measures both the thermal resistance and water vapour
resistance of fabrics [28].
A sweating guarded hot plate (Fig. 7.5) consists of test plate, guard
pate, temperature controller and water supply unit [20].
The test plate, fixed to a metal block with heating element, is a square
porous metal plate. The square test section in the centre of the plate is

Dynamic heat and mass transmission

151

7.5 Schematic diagram of sweating guarded hot plate.

surrounded by the guar plate, which prevents lateral heat leakage from the
edges of the specimen. The bottom plate beneath the test section prevents
the downward heat loss from the test plate and guard plate. This
arrangement ensures that both the heat and/or moisture transmit in upward
direction only, i.e. along the specimen thickness direction. A square fabric
specimen is mounted on the square porous test plate that is heated to a
constant temperature that approximates body skin temperature (35°C). The
plate temperature is measured by the sensor sandwiched directly underneath
the plate surface. The electrical power to maintain the constant temperature
is recorded. The whole apparatus is housed in a chamber so that the
environmental conditions can be carefully controlled. For the determination
of thermal resistance of the sample, the air temperature, relative humidity
and the air speed generated by the air flow hood are controlled as per the
standard specifications. The thermal resistance of the fabric is measured
in similar way as that of normal guarded hot plate system, i.e. without any
moisture vapour. Total thermal resistance (Rh) of the fabric under the steady
state condition is given by [22]
Rh = A(Ts – Ta)/H m2 °C/W

(7.9)

where A the area of the test section (m2), Ts the surface temperature of the
plate (°C), Ta the temperature of the ambient air (°C), and H the electrical
power (W).
To measure the moisture transmission characteristics of the fabrics,
distilled water is supplied to the surface of the porous plate from a dosing
device. The dosing device is normally activated when the water level in
the plate is about 1 mm below the plate surface. The water entering the
measuring unit is preheated. A level switch is connected to the measuring
unit to maintain a constant rate of evaporation. A water vapour permeable
and liquid water impermeable membrane is fitted over the plate. The test
fabric is placed above the membrane. The electrical power to maintain the

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Science in clothing comfort

plate at a constant temperature of 35°C is an indicator of water evaporation
rate. Air temperature is set at 35°C and relative humidity is controlled at
40%. After a steady state is reached, the total evaporative resistance (Rv)
of the fabric is calculated by using the following formula [29]:
Rt = A(Ps – P a)/H m2kPa/W

(7.10)

where Ps the water vapour pressure at the plate surface (kPa), Pa the water
vapour pressure of the air (kPa), and H the electrical power (W).

7.4.1

Measurement of condensation in the clothing

Condensation takes place in presence of very high gradient of vapour
pressure as well as temperature. It is a direct result of a fabric being
saturated by liquid perspiration [30]. It occurs within the fabric whenever
the local vapour pressure rises to the saturation vapour pressure at the
local temperature [31]. Condensation normally occurs when the
atmospheric temperature is very low; when the warm and moist air from
the body meets the fabric, it works as a cold wall and condensation occurs.
Sweating skin model is used to determine the condensation in the fabric
for both in steady and transient state conditions [32, 33]. In this model
two different procedures are used to analyze unsteady heat and moisture
processes. In one of the procedures the liquid water is injected close to the
hot side of the sample; it evaporates there and re-condenses toward the
cold impermeable side of the slab. In other procedure the hot plate is
directly exposed to the moist air flow. Transient temperature changes are
monitored and the total amount of absorption and condensation is measured
after a specific time. Based on the sweating skin model, Xiaohong et al.
[34] proposed an apparatus to investigate whether condensation occurs
on the fabrics or not. Sweating skin within the microclimate is simulated
by the use of a fully wetted qualitative filter paper heated to skin
temperature (32°C) using a hot plate. Two sensors are used to record and
display temperature and relative humidity simultaneously. Dynamic vapour
pressure is calculated using the data of relative humidity and temperature
by the following equations:

φ=

P
× 100%
Ps

(7.11)

and

⎡
⎛ T − 273.15 ⎞⎤
Ps = 4.607 exp ⎢17.06⎜
⎟⎥
⎝ T − 40.25 ⎠⎦
⎣

(7.12)

Dynamic heat and mass transmission

153

where P is moisture vapour pressure (mmHg) at temperature T (K); Ps is
saturation vapour pressure (mmHg) at same temperature and φ is the relative
humidity (%). The relationship between the water vapour pressure and
radius of water droplet when condensation occurs is given by the following
equation:
ln

P
2σ
1
=
⋅
Ps ρ w RT r

(7.13)

where r is radius of water droplet, σ is surface force of water, ρw is density
of water, R is constant.
Pressure (P)–temperature (T) diagram of wetted air is used to record
the condition of microclimate and study whether condensation is formed
on the inner surface of a fabric. In theory, condensation occurs under the
conditions of water vapour pressure present exceeding the saturation
vapour pressure. The saturation line is described as the water vapour
pressure giving rise to 100% relative humidity at a specific temperature.
A typical saturation line has been shown in the Fig. 7.6.
Keighley [35] and Ruckman [36] also suggested that the condensation
occurring on the fabrics may be predicted if a saturation line and water
vapour concentration line are utilized. Keighley [35] developed a method
that involved measurement of water vapour concentration utilizing infrared
absorption at the specific frequency of strong water vapour absorption.
Ruckman [36] provided a solution to the problem of condensation on the
inner surface of fabric by perforating metal cylinder simulating the
perspiring human body to investigate the couple mechanisms of water
vapour transfer and heat transfer.

7.6 The saturation line. [23]

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Science in clothing comfort

Fan et al. [37] and Murata [38] have also set experimental apparatuses
to measure the condensation in the fibrous material maintaining a hot and
humid surface and another cold wall. Fukazawa et al. [39] have developed
an apparatus to measure the water vapour resistance of the textiles with
and without temperature and pressure differences imposed on both sides
of the fabric, and also to see the effect of the temperature and pressure
difference on the condensation in the textile material.

7.5

Parameters expressing heat and mass
transmission

7.5.1

Evaporative transmissibility

The evaporative transmissibility is the ratio of moisture vapour permeability
index (im) to total insulation (im/clo) [40]. It is an indicator of the proportion
of the maximum evaporative cooling of sweat generated in a specific
environment. The effect of presence of air current is neglected here. Thus,
evaluation of the insulation and moisture evaporative capacity of a clothing
system is able to accurately estimate the relative advantages of the clothing
as compared with another, with regard to the thermal protection or strain
when the clothing is worn. The evaporative transmissibility (im/clo) is
helpful to compare the ensembles with different insulation values. Two
clothing ensembles with different thermal insulation characteristics but
same evaporative transmissibility would exchange same heat between the
body and the surrounding in the same environments at the same activity
levels. It is easy for clothing materials with high evaporative transmissibility
value (im/clo) to transport heat by means of both convective heat transfer
and evaporative cooling. But in case of environment with high humidity
and at low air speed, the evaporative cooling is less important and the
thermal transmission characteristics become the most important factor.

7.5.2

Permeation efficiency factor

Permeation efficiency factor (f pcl) describes the cooling efficiency of
sweating on the skin surface for a clothed human body. The permeation
efficiency factor (fpcl) ranges from zero, when a person wearing a completely
impermeable clothing, to unity, for a nude subject [41]. It is calculated in
terms of the convective heat transfer coefficient between the human body
surface to the environment and the intrinsic insulation of clothing. This
can be expressed by the following equation [42]:
f pcl = 1/ (1 + 0.143 × hc × I cl )

(7.14)

Dynamic heat and mass transmission

155

The relationship between permeation efficiency factor (fpcl) and moisture
vapour permeability index (im) is governed by the following equation [41]:
f pcl =

im
hc × ( I a + I cl )

(7.15)

where h c is the convective heat transfer coefficient (W/m2 °C), I cl the
intrinsic insulation of clothing (clo), and Ia the insulation of boundary air
layer (clo). Moisture vapour permeability index (im) is an indicator of the
evaporative performance of clothing.

7.5.3

Heat lost to the environment by evaporation

The heat lost to the environment by evaporation (E) is calculated using an
evaporative heat exchange coefficient and the water vapour pressure
difference between the skin and the ambient air. The equation is analogous
to the convective heat transfer equation:
E = heWs (Pss – Pa) W/m2

(7.16)

where he is evaporative heat transfer coefficient (W/m kPa); Ws is skin
wettedness (it is a dimensionless parameter defined as the ratio of
evaporative rate from skin, e, and the maximum evaporative rate of skin,
emax); Pss is water vapour pressure at the skin surface, i.e. the pressure of
saturated air at the skin temperature (kPa); Pa is water vapour pressure of
the ambient air (kPa).
The evaporative heat transfer coefficient H e for the outer air layer of a
nude person can be estimated from the convective heat transfer coefficient
(hc) using the Lewis ratio (LR), which describes the relationship between
convective heat transfer and mass transfer coefficients for a surface. Lewis
relation (LR) is the ratio of evaporative mass transfer coefficient to
convective heat transfer coefficient (hc).
2

LR = he / hc

(7.17)

The Lewis ratio equals approximately 16.5 K/kPa for typical indoor
conditions [43]. Evaporative heat loss from the skin depends on the amount
of moisture on the skin and the difference between the water vapour
pressure at the skin and in the ambient environment. Skin wettedness is
the ratio of the actual evaporative heat loss to the maximum possible
evaporative heat loss, emax, under the same environmental conditions and
for a completely wet skin the value of Ws is 1. Evaporative heat loss from
the skin is a combination of the evaporation of sweat secreted because of
thermoregulatory control mechanisms and the natural diffusion of water
through the skin. With no regulatory sweating, skin wettedness caused by

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Science in clothing comfort

diffusion is approximately 0.06 for normal conditions. For large values of
emax or long exposures to low humidities, the value may drop to as little as
0.02, because dehydration of the outer skin layers alters its diffusive
characteristics. Skin wettedness is strongly correlated with warm
discomfort. For clothed subjects, w > 0.2 is perceived as uncomfortable.
Skin wettedness can theoretically approach 1.0 while the body still
maintains thermoregulatory control, but in practice it is difficult to exceed
0.8 [44].

7.5.4

Clothing ventilation

The Clothing Ventilation Index is a quantitative which predicts the
effectiveness, preference and suitability of clothing assemblies; firstly, to
ensure that the clothing is worn and used correctly and, secondly, to
improve performance by minimising heat strain, sweat retention and
thermal discomfort. Ventilation is vital to the removal of sensible and
insensible heat and, therefore, an important determinant of thermal comfort.
Thermal comfort and heat loss from the body by convection and
evaporation of sweat can be measured using Fanger’s model of thermal
comfort [45]. As the thermoregulatory system is only able to control the
loss of sensible and insensible heat if there is sufficient quantity of air
flowing through the micro-environment, the clothing ventilation technique
became important in determining the performance of all clothing
ensembles. The factors influencing air exchange are air permeability of
fabric, design, sizing (fit), wind and the resilience of fabrics.
The clothing ventilation is an evaluation method of microclimate air
exchange, not the physiological response of human body. The fit of the
clothing has a direct effect on the ventilation and there is a need for
measuring standard sizes and fit for comparison purpose and repeatability
of results [46].

References
1.
2.
3.
4.
5.
6.

SPENCER - SMITH J . L ., ‘The physical basis of clothing comfort, Part 2: Heat transfer
through dry clothing assemblies’, Clothing Res J 5(1) 3–17, 1977.
NORDON P ., MACKAY B . H ., DOWNES J . G . and MCMAHON G. B., ‘Sorption kinetics of
water vapour in wool fibres: Evaluation of diffusion coefficients and analysis
of integral sorption’, Text Res J 30, 761–770, 1960.
LI Y . and HOLCOMBE B . V ., ‘A two-stage sorption model of the coupled diffusion
of moisture and heat in wool fabrics’, Text Res J 62(4), 211–217, 1992.
LI Y . and LUO Z . X ., ‘Physical mechanisms of moisture diffusion into hygroscopic
fabrics during humidity transients’, J Text Inst 91(2), 302–316, 2000.
NORDON P . and DAVID H . G ., Int J Heat Mass Transfer 10, 1967.
CASSIE A . B . D ., ATKINS B . E . and KING G ., ‘Thermoplastic action of textile fibres’,
Nature 143, 162, 1939.

Dynamic heat and mass transmission
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.

22.
23.
24.
25.
26.
27.

CHEN Y . S ., FAN J .

157

and ZHANG W., ‘Clothing thermal insulation during sweating’,
Text Res J 73(2), 152–157, 2003.
LI Y ., ‘Fabric wetting factors’, Text Asia 6, 39–41, 1999.
MIZUTANI C ., TSUJII Y ., and BERTONIERE N ., ‘Effect of fibre structure on heat of
wetting of cotton and regenerated cellulosic fibres’, Text Res J 69(8), 559–564,
1999.
KIM J . O ., ‘Dynamic moisture vapour transfer through textiles. Part III: Effect of
film characteristics on micro climate moisture and temperature’, Text Res J 69(3)
193–202, 1999.
WOODCOCK A . M ., ‘Moisture transfer in textile system’, Text Res J 36, 855–856,
1966.
LI Y ., The science of clothing comfort, Text Progress 31(1/2), 2001.
LI Y . and HOLCOMBE B . V ., ‘Fibre hygroscopicity and thermoregulatory responses
during exercise’, in Proceedings of 2nd Asian Textile Conference, Seoul, South
Korea, 1993.
LI Y ., The buffering effect of hygroscopic clothing against rain, in Proceedings
of 4th Asian Textile Conference, Taipei, Taiwan, 1997.
QIAN X ., FAN J ., ‘A quasi-physical model for predicting the thermal insulation
and moisture vapour resistance of clothing’, Applied Ergonomics 1–14, 2008.
MIN K ., SON Y ., KIM C ., LEE Y . and HONG K ., ‘Heat and moisture transfer from skin
to environment through fabrics: A mathematical model’, Int J Heat and Mass
Transfer 50, 5292–5304, 2007.
DAS A ., KOTHARI V . K . and BALAJI M., ‘Studies on cotton-acrylic bulked yarns and
fabrics: Part II – Fabric characteristics’, J Text Inst 98(4), 363–375, 2007.
DAS A ., ZIMNIEWSKA M . and MAL R . D ., ‘Studies on cotton-acrylic bulked yarns
produced form different spinning technologies: Part II – Fabric characteristics’,
J Text Inst 100(5), 420–429, 2009.
DAS A ., ISHTIAQUE S . M . and SINGH R . P ., ‘Packing of micro-porous yarns: Part II
– Optimization of fabric characteristics’, J Text Inst 100(3), 207–217, 2009.
YASUDA T ., MIYAMA M . and YASUDA H ., ‘Dynamic water vapor and heat transport
through layered fabrics, Part III: surface temperature change’, Text Res J 64,
457–461, 1992.
MCCULLOUGH E . A ., The transient thermal responses of different types of clothing
due to humidity step changes. In Proceedings of the Second International
Symposium on Clothing Comfort Studies. Mt. Fuji Institute of Education and
Training, Japan, 1991, 1–22.
HUANG J ., ‘Thermal parameters for assessing thermal properties of clothing’, J
Therm Biol 31, 461–466, 2006.
DAS B., DAS A., KOTHARI V. K., FANGUEIRO R. and DE ARAUJO M., ‘Moisture transmission
through textiles – Part II: Evaluation methods and mathematical modelling’,
AUTEX Res J 7(3), 194–216, 2007.
RUGH J . P ., FARRINGTON R . B ., BHARATHAN D ., VLAHINOS A . and BURKE R ., ‘Predicting
human thermal comfort in a transient non-uniform thermal environment’, Eur
J Appl Physiol 92(6), 721–729, 2004.
WANG L . P . and LI C ., ‘A new method for measuring dynamic fabric heat and
moisture comfort’, Exp Ther & Fluid sci 29, 705–714, 2005.
HES L . and DOLEZAL I ., ‘New method and equipment for measuring thermal
properties of textiles’, J Text Mach Soc Jpn 42(8), T124–128, 1989.
CONGALTON D ., ‘Heat and moisture transport through textiles and clothing
ensembles utilizing the “Hohenstein” skin model’, J Coated Fabrics 28(1), 183–
196, 1999.

158
28.
29.
30.
31.
32.
33.
34.
35.
36.
37.

38.
39.

40.
41.
42.
43.
44.
45.
46.

Science in clothing comfort
MCCULLOUGH E . A ., HUANG J . and KIM C . S ., ‘An explanation and discussion of
sweating hot plate standards’, J ASTM Int 1(7), 13, 2004.
HUANG J ., ‘Sweating guarded hot plate test method’, Polymer Testing 25, 709–
716, 2006.
REN Y . J . and RUCKMAN J . E ., ‘Water vapour transfer in wet waterproof breathable
fabrics’, J Indus Text 32(3/1), 165–175, 2003.
RUCKMAN J . E ., ‘Water resistance and water vapour transfer’, Textiles in Sport,
editor Shishoo R., Woodhead Publishing Limited, Cambridge, 2005.
MOTAKEF S . and EL - MAHER M . A ., ‘Simultaneous heat and mass transfer with phase
change in a porous slab’, Int J Heat Mass Transfer 29(10), 1503–1512, 1986.
WIJEYSUNDERA N . E ., HAWLADER M . N . and TAN Y . T ., ‘Water vapour diffusion and
condensation in fibrous insulation’, Int J Heat Mass Transfer 32(10), 1865–
1878, 1989.
XIAOHONG Z ., SHANYUAN W. and GUANLU Y ., ‘An apparatus used to investigate
condensation for fabrics, laminates and films’, J Indus Text 32(3), 177–186,
2003.
KEIGHLEY J . H ., ‘Breathable fabrics and comfort in clothing’, J Coated Fabrics
15(10), 89–104, 1985.
RUCKMAN J . E ., ‘Analysis of simultaneous heat and water vapour transfer through
waterproof breathable fabrics’, J Coated Fabrics 26, 293–307, 1997.
FAN J . and CHENG X . Y ., ‘Heat and moisture transfer with sorption and phase
change through clothing assemblies, Part II: Theoretical modelling, simulation
and comparison with experimental results’, Int J Heat Mass Transfer 75(3),
187–196, 2005.
MURATA K ., ‘Heat and mass transfer with condensation in a fibrous insulation
slab bounded on one side by a cold surface’, Int J Heat Mass Transfer 38(17),
3253–3262, 1995.
FUKAZAWA T ., KAWAMURA Y ., TOCHIHARA Y . and TAMURA T ., ‘Water vapour transport
through textiles and condensation in clothes at high altitudes – combined
influence of temperature and pressure simulating altitude’, Text Res J 73(8),
657–663, 2003.
GOLDMAN R . F ., Evaluating the Physiologic Effects of Clothing on the Wearer,
US Army Research Institute of Environmental Medicine, Natick, 1978, 1–21.
NISHI Y ., GONZALEZ R . R . and GAGGE A . P ., ‘Direct measurement of clothing heat
transfer properties during sensible and insensible heat exchange with thermal
environment’. ASHRAE Trans 81, 183–199, 1975.
NISHI Y . and GAGGE A . P ., ‘Moisture permeation of clothing - A factor governing
thermal equilibrium and comfort’, ASHRAE Trans 76, 137–145, 1970.
MCCULLOUGH E . A ., ‘Factors affecting the resistance to heat transfer provided by
clothing’, J Therm Biol 18, 405–407.
ARENS E . A . and ZHANG H ., The Skin’s Role in Human Thermoregulation and
Comfort, Center for Environmental Design Research, University of California,
Berkeley, 2006.
FANGER P . O ., Thermal Comfort, McGraw–Hill, New York, 1972.
LUMLEY S . H ., STORYT D . L . and THOMAS N . T ., ‘Clothing ventilation-update and
applications’, Applied Ergonomics 22(6), 390–394, 1991.

8
Garment fit and comfort

8.1

Introduction

Modern consumers demand apparel products with superior multifunctional
and comfort performance to satisfy their physiological and psychological
needs. Garment size, fit and pressure comfort have been identified as
important attributes. No matter how well a fabric is engineered to have
optimum value of heat, moisture or air transmission, the clothing produced
from this fabric cannot be regarded as comfortable if it does not fit properly.
While the clothing comfort related to tactile aspects, thermal and moisture
transmission and aesthetic appearance depend on the type of materials
used and the design of the clothing, the comfort related to garment fit
mainly depends on the size and design of garments. The relationship of
size of garment to the size of body is very complex and requires detailed
analysis of many complex factors. The clothing is expected to conform to
our body shape and is our nearest environment, so it is expected to fit
closely and deform in synchronization with our body movement.
Individuals have apparel fit preferences based upon aesthetic and functional
expectations. When we judge the fit of a garment, the judgment is mainly
based on both visual and tactile sensations. The comfort level of the
garment is judged based on both tactile and aesthetic responses. The
concept of comfort encompasses many dimensions, including physical,
psychological, and social comfort. In order to understand about comfort
sensations related to garment fit, the responses related to tactile and
aesthetic aspects also need to be considered. The clothing comfort related
to fit depends on the mass of clothing ensemble, ease of movement of
clothing over skin, pressure applied on the body surface and ventilation
provided by the clothing. The sensory responses of clothing comfort can
be divided into two categories: one is the feel of the fabric on the surface
of the skin and the other garment fit sensations. The feel on the skin surface
of the fabric is further subdivided into sensations of tickle, prickle, allergic
reactions, contact thermal sensations, perception of moisture, and abrasion.
Garment fit sensations are subdivided into general pressure sensations and
localized pressure sensations [1]. A badly fitting garment can restrict cardio-

159

160

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vascular flow, causes skin irritation, results unpleasant thermal or moisture
conditions and ultimately results in discomfort to the wearer. The garment
fit related comfort is very crucial for performance clothing. The
performance clothing should fit better and not limit job performance. They
should provide comfort fit design which enable a greater range of
movement while stretching and bending, improve mobility with more room
throughout the body, provide a more tailored fit and better overall comfort
and be easier to wear and take off.

8.2

Body dimensions and pattern

Relationship between the size and design of clothing with the form of the
body is a complex problem of ergonomics engineering. Determination of
even the most basic pattern shapes requires complex decisions related to
dimension, all of which are related to the dimensions of the body for which
the clothing is produced, but not necessarily are equal to the body size.
Designing clothing for a specific individual body size also poses
tremendous challenges when one wants to consider all the aspects, like
fit, design, aesthetic or other comfort related aspects together. Extensive
use of computer software helps in the development of patterns by measuring
the body, analyzing anthropometric data, drafting clothing patterns, and
designing and manufacturing clothing. Such technology facilitates largescale anthropometric studies and the development of improved-fit models
and sizing standards for mass production. It also encourages the expansion
of custom clothing production by providing a more accurate and costeffective means for fitting the individual. Essentially, the problem of fitting
a garment to the human body involves the spatial relationship of the twodimensional garment plane to the body surface [2].
The dimensions of pattern of a garment are not identical to the
corresponding dimensions across the body surface. Therefore, the process
of determining pattern dimensions from body dimensions must ultimately
be evaluated as the three-dimensional correspondence of the resulting
garment to the body form. Pattern dimensions have often been determined
by a process of (1) taking linear (length and circumference) measurements
over the body surface with measuring tape and then (2) applying those
measurements in some predetermined manner to the pattern draft. This
process of garment sizing may results in improper fit and needs repeated
trials and fittings of the garment by a skilled technician after the pattern is
cut from cloth. Experience, therefore, demonstrates that these linear bodysurface measurements are not directly applicable to pattern dimensions
and are useful primarily as approximations. Another type of data
traditionally used in pattern development is the visual assessment of body
configuration by the expert eye of the tailor.

Garment fit and comfort

161

Gazzuolo et al. [2] compared the photographic body data with linear
anthropometric data and subsequently predicted pattern dimensions. Their
work involved taking traditional linear measurements of body,
photographing the body and measuring the photographs. They determined
the pattern shapes by a methodology which located fabric planes directly
on the body. They have (i) developed statistical models predicting key
measurements of a garment pattern from standard linear measurements;
(ii) developed comparable models for predicting garment pattern
measurements from quantities measured from the photographs; and (iii)
compared these models to determine whether linear or photographic
measurements had greater predictive power for determining garment
patterns. They have observed that the photographic model has predictive
power in the determination of pattern dimensions; there are several
advantages to this method of anthropometric data collection. Photographic
techniques are far less intrusive and more efficient with regard to time,
effort and cost than are manual tape measure techniques.

8.3

Garment fit and comfort relationship

8.3.1

Tight-fit and loose-fit

The size and fit of a garment has direct influence on the comfort
characteristics. In a loose-fitting garment the volume of entrapped still air
is more and has larger openings at places like the neck, waist, wrist, and
ankles, which cause greater reductions in their thermal insulation and
moisture vapour resistance during windy conditions and body movement.
Figures 8.1a and 8.1b show the typical shapes of loose-fit and tight-fit
garments [3]. The tight-fit garment is designed to fit tight to the skin in
order to allow the technical aspects of the garment to work effectively.
However, no such garment should be so tight as to restrict freedom of
movement. Generally the tight-fit garment is designed to fit all contours
of the body and compress core muscle groups. The normal-fit garment, on
the other hand, provides a less tight-fit but still provides all the benefits of
moisture transmission and thermal management in appropriate locations.
The loose-fit garments are designed as a comfort fit with all the moisture
management benefits and generally worn as a casual garment or an outer
garment. In a research work conducted by McCullough et al. [4], the
thermal insulation of two pairs of loose-fitting and two pairs of
corresponding tight-fitting long trousers were measured, using a standing
manikin in little wind (air velocity in the chamber was less than 0.11 m/s).
They have observed that the loose-fitting trousers have much greater
thermal insulation than the corresponding tight-fitting trousers (33% more
for the tweed trousers and 48% more for the denim trousers). In another

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study conducted by Havenith et al. [5] the thermal insulation of three
clothing ensembles on four combinations of body postures and movements
(two with loose fit and two with tight fit) when the subjects were sitting
and walking at two speeds and at three wind speeds were determined.
They have concluded that the tight-fit clothing had 6–31% less insulation
than loose-fit clothing. The difference in thermal insulation values between
tight-fit and loose-fit clothing was found to be maximum in sitting
condition. They have also observed that the difference in thermal insulation
value was lower in presence of wind.

8.1a Typical loose-fit garment.

8.3.2

8.1b Typical tight-fit garment. [3]

Garment fit and pressure

The comfort related to garment pressure and fit mainly depend on the
tactile responses of human body which include thermal and moisture
perceptions, prickle related to allergic reactions and reactions to the surface
texture of materials, friction between clothing and skin surface and pressure
sensations. Two categories of tactile sensations are somesthetic sensations
and kinesthetic sensations. The somesthetic sensations are touch response
from the nerves in the surface of the skin. Tickle, prickle and abrasion are
somesthetic responses to clothing. The kinesthetic sensations or the deep
pressure sensations are felt by the nerves in the muscles and the joints [6].
Pressure sensations created by the resistance of the garment to movement
and the weight of the garment in response to movement are kinesthetic
responses to clothing fit [7].
The multidirectional and random forces generated during dynamic
interactions between a garment and a moving human body generates
pressure sensations. The discomfort level of clothing pressure was found
to be between 60 and 100 g/cm2, depending on the individual and the part
of the body concerned, which is similar to blood pressure in the capillary

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163

blood vessels near the skin surface [8]. So, the pressure exerted by a
garment is an important design criterion and is affected by its style, fit and
mechanical properties. It is directly related to the degree of space allowance
(F, the difference between the surface areas of garment and body) between
the body and the garment during body movement. According to the degree
of space allowance (F), garments can be classified into three types:
foundation garments (F < 0), perfectly fitting garments (F = 0) and loose
fitting garments (F > 0). In foundation garment the area of garment is less
than the body area (such as women’s close-fitting foundation garment,
pressure garment, etc.). These are mainly designed to apply a certain level
of pressure on the body part concerned when the body is in active condition
or at rest. The perfectly fitting garments are those where the garment area
is exactly equal to the body area (such as tights, socks, body stockings,
etc.) and have a figure-shaping function but are not designed to apply
pressure to the body. Therefore, a perfectly fitting garment only restricts
body movement as a result of garment pressure, but no pressure is applied
when the body rests. In loose-fitting garments the area of the garment is
larger than the body area (such as loose-fit outer wear, casuals etc.). As
the movement of body can reduce the space allowance, loose-fitting
garments may also sometime exert pressure on the body at contact areas.
Therefore, the level of garment pressure varies significantly for different
wear situations, depending on four factors namely, design and fit of the
garment, shape of the body part, mechanical properties of the underlying
tissue, and mechanical properties of the fabrics [9].
The evaluation of human comfort due to garment fit and subjective
garment pressure sensations are generally done by conducting wear trials
[10–12]. In the study conducted by Makabe et al. [11] the garment pressure
was measured on the covered area at the waist for corsets and waistbands
and conducted a sensory test for garment pressure. Their results indicate
that the garment pressure at the waist is influenced by the area covered,
respiration and the ability of the garment to assume the complex body
curvature during the body movement. During subjective evaluation of
garment pressure and comfort sensations at the waist, they have observed
that in the lower garment pressure range (0–15 gf/cm 2) no sense of
discomfort is there. In the medium range of garment pressure (15–25 gf/cm2)
negligible or only slight discomfort is perceived. But in higher pressure
range, i.e. when the garment pressure exceeds 25 gf/cm 2, extreme
discomfort is perceived. Denton [8] pointed out that as the body curvature
increases the garment pressure on the body increases. The body curvature
of average women’s waist at the sides is roughly 3.5 times greater than
that at the front, so unwanted pressure on the sides of the waist is 3.5
times greater than the desired figure flattening pressure on the front [9].

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Similar finding has also been reported during the measurement of internal
pressure exerted by pressure bandage using Laplace equation [13]. As per
the Laplace equation it is expected that the exerted internal pressure (P)
would increase with increase in curvature of the limb. The Laplace equation
is given below,
P = T × n ×w
r

(8.1)

where T is tension of bandage during wrapping; n is number of wraps; r is
radius of curvature; and w is width of bandage.

8.3.3

Evaluation of tactile perception to fit

Various methods have been developed to measure the human perceptions,
like odours, tastes etc. Ashdown and DeLong [7] adapted the test method
for measuring tactile perception to fit, which was developed by the ASTM
Committee E-18 for sensory evaluation of products. Constant stimulus
difference (i.e. difference from control value) test was used as the model
in the development of the perception of fit tests. Two types of thresholds
were identified by this test: the difference threshold (or) the extent of
change in the stimulus that produces a noticeable difference; and the
recognition threshold (or) the extent of change in a stimulus necessary for
positive identification of the difference. In the first part of this test a series
of garments (pants) along with their corresponding control (garments) were
presented to a panel of experts. The experts then rated the difference of
the sample from the control. The scale for pants provided the response
choices of ‘looser’, ‘a little looser’, ‘the same’, ‘a little tighter’ and ‘tighter’
for the waist, hips and crotch. The second part of the perception test was
designed to address the large number of interactions that occurred in the
first part of the perception test. In order to focus the subjects’ attention on
one area of concern, they were told what area of the test samples (pants)
would vary from the control sample. The second test was therefore
performed with variations at a single location. Two experts were asked to
respond to test samples (pants) with hip or crotch variations. In the second
type of perception test, the experts were informed that the variations were
all at this specific location. The final perception test was carried out to
determine the significance of the thresholds perceived in relation to comfort
or discomfort perceptions with garment fit. The participants were given
only the test garment that they had perceived as different from the control
to try on in a preference test. A mirror was provided and subjects were
asked to indicate whether they found the garments are comfortable or not,
even though they perceived differences from the control garment.

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165

Psychophysical scaling technique was used by You et al. [14] to assess
the pressure perception and other relative wearing sensations during
wearer trials of tight-fitting garments. The sense of pressure was recorded
on a scale of 0–10. One tight-fitting pant, with very high clothing
pressure, as presented to subjects as the standard for the maximum degree
of pressure, was indexed as 10. On the other hand, when the subject was
naked, i.e. at the minimum degree of pressure, the scale was indexed as
0. The subjects were asked to rate the sense on a scale 0–10. Every subject
was asked to assess the pressure sensation of each area while wearing
the garments.

8.4

Factors related to garment fit

8.4.1

Air gap thickness

Chen et al. [15] reported that, in case of smaller air gap between skin
and the garment (for medium fit garment), both the thermal insulation
and moisture vapour resistance increases at higher rate with the increase
in the thickness of the air gap between the garment and the body. The
rate of increase gradually decreases as the air gap becomes higher (as
the garment becomes loose-fit), and the rate of increase is much less
than that of the theoretically ideal still air due to natural and forced
convection. When the air gap exceeds a certain value (in case of very
loose-fit garment), possibility of drop in thermal insulation and moisture
vapour resistance is there with the increase in the air gap. This is due
to the fact that in loose-fit garments, there are easy passages of adjacent
atmospheric air to penetrate through the openings and interfere with
the still air of the microclimate. Also the air gap results in greater natural
convection. Thermal insulation and moisture vapour resistance reach a
maximum at a certain air gap thickness depending on fabric properties,
wind conditions and garment fit. Tighter fitting garments are preferable
to keep the body warm in windy. Chen et al. [15], during their study
with open-structured knitted garment, reported that in absence of wind
the maximum thermal insulation was reached with air gap thickness of
approximately 1 cm, corresponding to a difference of 7.5 cm in girth
between the garment and the body. On the other hand, in windy
conditions the maximum thermal insulation reached at lower air gap
thickness (i.e. approximately 0.6 cm thick), corresponding to a
difference of 5 cm in girth between the garment and the body. More
natural and forced convection is believed to cause the slower increase
of thermal insulation and vapour resistance with the increase in air gap
thickness.

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8.4.2

Garment ventilation

Most of the garments, especially the protective clothing, are designed to
protect the human being from hostile thermal, biological, chemical
environments, etc. The comfort properties of these garments are of
considerable interest for their satisfactory performance. In addition to the
selection of raw material, constructional parameters and finish, garment
fit also gains its importance in deciding the transfer of heat and moisture
to the environment. Numbers of literatures [16–18] are available which
reveal the effect of ventilation and fit on the comfort properties of protective
clothing. Daanen et al. [16] investigated the ventilation rate by changing
the fit of the garment (jackets). The jackets were made from normal fit to
oversize by using metal rings inside. These rings enlarged the air volume
between skin and clothing by about 60%. Nine male subjects participated
in the study. The 3D scanner method was used for measuring the volume
of trapped air. The volume also varied due to the variations in body
dimensions of the subject. Ventilation rate was measured during standing,
walking, swinging arms and bending arms by TNO tracer gas method [17].
The ventilation rate was found to be higher (200 litre/min.) in loose-fit
garment than normal-fit garment (120 litre/min.). So, looser the garment
more the heat loss was observed. Another way to enhance the heat loss is
to make clothing more air permeable. Havenith et al. [18] investigated the
effect of air permeability on heat strain of chemical protective clothing.
He has observed that the tolerance time when walking on a treadmill has
increased from 174 ± 42 to 203 ± 56 min by increasing the ventilation
through the material from 186 to 365 litre/m2. It can be concluded that fit
of the garment and air permeability are the two important factors in deciding
the heat and moisture transfer of clothing.

8.4.3

Fluctuating microclimate in loose-fit garment

Due to metabolic action, the human body continually produces heat. The
clothing system contributes greatly to thermal comfort through the
regulation of heat balance. The size and fit of a garment influences the
thickness of microclimate. The fluctuation of microclimate occurs very
frequently due to activity and body movement. This phenomenon is very
significant in case of loose-fit garments. Shigaki et al. [19] have reported
the changes in garment surface temperature on a garment made of cotton
and polyester fabrics, due to fluctuation of relative humidity of
microclimate. They have reported that with the rapid fluctuation of relative
humidity of microclimate the surface temperature of cotton garment
fluctuates significantly, whereas in case of polyester garment the fluctuation
was smaller than cotton. Figure 8.2 shows the typical changes in the surface

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167

8.2 Typical garment surface temperature (ST) response with
rapid change in relative humidity (RH).

temperature of cotton and polyester garments with the humidity change in
the microclimate. The quick rises and falls in the temperature were observed
for cotton garments. It corresponded to the rapid humidification and
dehumidification of the microclimate. The similar results were obtained
in the case of polyester fabric. However, the temperature changes for
polyester were smaller than for cotton. This tendency shows that the
hygroscopicities of fabrics correspond directly to their heat of absorption
for moisture.
Figure 8.3 shows the typical changes in surface temperature under the
increasing and decreasing humidity at very low rate. It has been reported
that under this condition, the surface temperature changes were very
small [18]. The rate of the temperature change was found to increase with
the increase in the rate of relative humidity. The increase in surface
temperature for cotton fabric was higher than for polyester. Regardless of
the increasing rate of the humidity, the hygroscopic fabric produces the
adsorption heat.
The rapid and large changes in the fabric temperature against the skin
due to fluctuation of relative humidity of microclimate, which have been
observed especially for hygroscopic cotton garment, affect the thermal
comfort of clothing.

8.4.4

Garment fit and pressure sensation

The sensation of pressure during wearing of tight-fit garment is a major
component of comfort and the pressure applied by a garment mainly
depends on the extensibility of fabrics, the fitness of garments and the

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169

measured. This was done by drawing a series of lines on the thigh-fit at
regular intervals and measuring the changes in dimension that took place
when subjects were wearing the garment. They have reported that the
garment comfort during wearing has a negative correlation with the feeling
of fetter, scratchy, heavy and the sensation of pressure, and has a poor
correlation with the feeling of softness and smoothness. The pressure
sensation, wearing comfort of pressure and fettered feelings, are directly
related to the garment fit. They have also reported that the garment fit and
the fabric extensibility have good ability to predict pressure sensation for
clothing, when garments have the same style and the skin stretch of subjects
is not high.
The garment fit is a problem of pressure against the skin reaching
unpleasant levels or restricting body motion and increasing the energy
cost of movement. Individuals vary significantly in their sensitivity to
garment pressure. The acceptance of a normal garment can be increased
by designing the garment for optimum pressure, i.e. reduction in the
pressure. Perfectly fitting garments are required to be designed to fit the
body shape without exerting any specific shaping pressure. The garments
should be more or less skin-tight to accommodate body movement and
provide comfort. A fabric should have lower tensile modulus in multidirections and effective elastic recovery to ensure that the garment does
not become loose and buckled on the body parts and to accommodate body
movement [9]. The garment only constrains body movement as result of
garment pressure, but no pressure is applied when the body rests. The
external forces exerted by human body are balanced by fabric internal
stresses (tensile, shear and bending) and the inertia force of the garment
during body movement.

8.5

Measurement of garment fit

Croney [22] defined anthropometry as ‘the practice of measuring the human
body’. He also recommended that the static and dynamic anthropometric
data will provide the designer with an armature of dimensions around which
ideas can grow. Pheasant [23] expands this definition to ‘applied
anthropometrics’, which include numerical data concerning size, shape
and other physical characteristics of human beings that could be applied
in the design context.
Traditionally tailors have accurately measured the human body size
for garment making with measuring tape based on their experience. They
recognized similarities between the garments they made for individuals
and began to think in terms of proportionally scaled patterns for people
of different sizes, known as “graded” sets of clothing sizes [24]. As a

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result ready-to-wear is now the principle source of clothing production
available to the global mass market. Efficient mass production of clothing
requires a method of producing accurate size of garment which will fit
properly. The traditional methods of body size measurement are timeconsuming, chances of human error, inaccuracies of measurement and
most important is that one has to touch the body physically during body
size measurement. Fan et al. [25] mentioned that each size has a distinct
code (e.g. small, medium, large or 10, 12, 14) to guide consumers to
choose apparel which fits their body properly. They have also emphasized
the importance of a 3D digitization of body form and clothing surface to
assist the spatial analysis of clothing appearance, body measurement and
garment fit.
3D laser scanning is a process used to build a digital 3D copy of a
physical body surface very accurately without touching. The development
of 3D laser scanning technology has solved many of the problems
associated with the traditional body size measurement systems. This system
generates the accurate body size of a person in seconds. At present this
technology is used for different purposes, namely apparel design (protective
wear, wearable technology, thermal comfort, athletic equipment/uniform,
mass communication); ergonomics (validation of models, seat design);
reverse engineering (finite element analysis solution, rapid prototyping,
standard/tolerance); and biomedical applications (obesity determination,
body asymmetries, rehabilitation engineering) [26]. Figure 8.4 shows the
principle of 3D laser scanning system of human body size measurement.
The system consists of two primary components: (i) A hardware system

Enlarged view of
scanning assembly

Scanning
assembly

Scanning
assembly

Scanning
assembly

CCD Cameras
Scanning
assembly

Laser source

8.4 Schematic diagram of 3D laser scanning system of body size measurement.

Garment fit and comfort

171

which consists of charge coupled device (CCD) camera, laser source and
computer, and (ii) image recognition software.
It can be observed from Fig. 8.4 that the scanning assembly consists
of a structural frame to keep the scanning devices in their required
positions. Curtains are generally hung from the frame to minimize the
interferences of outside light. The vertical columns, located in the four
corners, are containing the scanning assemblies. The scanning assembly
(shown in enlarged view) consists of a laser and two CCD cameras. All
the four scanning assemblies are connected with an elevator assembly
that travels up and down in the vertical columns. After the proper
calibration, all the four elevator assemblies travel downward direction
in unison and sweep the scanning zone with a horizontal plane of laser
light. During this process the laser light illuminates the contour of the
human body standing within the scanning area and the CCD cameras
record discrete points on these contours at each horizontal point [26].
The total scanning process takes few seconds. The data from the CCD
cameras are then transmitted to the computer through the A/D converter
and the image recognition software finally creates a point cloud
representation of the body contour. The point cloud data are then used
for the representation of human body size.

References
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.

SMITH J . E .,

‘Clothing’, Textiles 16(1), 23–27, 1986.
and BYE E., ‘Predicting garment pattern
dimensions from photographic and anthropometric data’, Applied Ergonomics
23(3), 1992.
http://www.baselayer.co.uk/fit-and-size-guide.php
MCCULLOUGH E . A ., JONES B . W. and HUCK J . A ., ‘Comprehensive data base for
estimating clothing insulation’, ASHRAE Trans 91, 29–47, 1985.
HAVENITH G ., HEUS R . and LOTENS W. A ., ‘Resultant clothing insulation: A function
of body movement, posture, wind, clothing fit and ensemble thickness’,
Ergonomics 33(1), 67–84, 1990.
MCBUMEY D . and COLLINS V . B ., Introduction to Sensation/Perception, PrenticeHall Inc, Englewood Cliffs, 1977.
ASHDOWN S . P . and DELONG M ., ‘Perception testing of apparel ease, Variation’,
Applied Ergonomics26(1), 47–54, 1995.
DENTON M . J ., ‘Fit, stretch and comfort’, Textiles 12–17, 1972.
ZHANG X ., YEUNG K . W. and LI Y ., ‘Numerical simulation of 3D dynamic garment
pressure’, Text Res J 72, 245–252, 2002.
MAKABE H ., MOMOTA H ., MITSUNO T . and UEDA K ., ‘A study of clothing pressure
developed by the girdle’, J Jpn Res Assoc Text End-uses 392, 424–438, 1991.
MAKABE H ., MOMOTA H ., MITSUNO T . and UEDA K ., ‘Effect of covered area at the
waist on clothing pressure’, Sen-iGakkaishi 4109, 513–521, 1993.
MAKABE H ., MOMOTA H ., MITSUNO T . and UEDA K ., A study of clothing pressure
developed by the brassiere, J Jpn Res Assoc Text End-uses 392, 416–423, 1991.
GAZZUOLO E ., DELONG M., LOHRT M., LABAT K .

172
13.
14.
15.
16.
17.
18.

19.
20.
21.
22.
23.
24.
25.
26.

Science in clothing comfort
THOMAS S ., ‘The use of the Laplace Equation in the calculation of sub-bandage
pressure’, EMWA J 1, 21–23, 2003.
YOU F ., WANG J . M ., LUO X . N ., LI Y . and ZHANG X ., ‘Garment’s pressure sensation:
subjective assessment and predictability for the sensation’, Int J Clothing Sci
Tech 14(5), 307–316, 2002.
CHEN Y. S., FAN J ., QIAN X. and ZHANG W., ‘Effect of garment fit on thermal insulation
and evaporative resistance’, Text Res J 74, 742–748, 2004.
DAANEN H . A . M ., HATCHER K . and HAVENITH G ., ‘Determination of clothing
microclimate volume’, Environmental Ergonomics, Elsevier Ergonomics Book
Series, 3, 361–368, 2005.
HAVENITH G ., HEUS R . and LOTENS W. A ., ‘Clothing ventilation, vapour resistance
and permeability index: changes due to posture, movement and wind’,
Ergonomics 33(8), 989–1005, 1990.
HAVENITH G ., VUISTER R . G . A . and WAMMES L . J . A ., The effect of air permeability
of chemical protective clothing material on the clothing ventilation and vapour
resistance, Report TNO-TM 1995 A 63, TNO Human Factors, Soesterberg, The
Netherlands, 1995.
SHIGAKI M ., NIKI Y ., NISHIZAWA K ., USHIODA H ., NAKANISHI T . and NAKAJIMA T ., ‘Effect
of hygroscopic fabrics on wear comfort in the fluctuating microclimate of
clothing’, J Therm Biol 18(5/6), 429–434, 1993.
ZHANG X ., LI Y ., YEUNG K . W., MIAO M . H ., and YAO M ., ‘Mathematical simulation of
fabric bagging’, Text Res J, 2000 70(1) 18–28.
ZHANG X ., LI Y ., YEUNG K . W ., MIAO M . H ., and YAO M., ‘Fabric – bagging: stress
distribution in isotropic and anisotropic fabrics’, J Text Inst 91(4), 563–576,
2000.
CRONEY J., Anthropometry for Designers, Van Nostrand Reinhold Ltd., New York,
1981.
PHEASANT S ., Bodyspace, Anthropometry, Ergonomics and the Design of Work,
Taylor and Francis, London, 1986.
ExploreCornell, Made to Measure – A Historical Look at Custom Fit, http://
www.explore.cornell.edu/scene.
FAN J ., YU W ., and HUNTER L ., Clothing Appearance and Fit: Science and
Technology, Woodhead Publishing Limited, Cambridge, 2004.
LERCH T ., MACGILLIVRAY M ., and DOMINA T ., ‘3D laser scanning: A model of
multidisciplinary research’, Journal of Textile and Apparel, Technology and
Management 5(34), 1–22, 2006.