Comparisons

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Comparison Between Different Fibers

Proper ties

Cotton
Cellulose (NATURAL)
125-150 convolutions per inch Creamy white color, when its picked

Flax
Cellulose (NATURAL)
Yellowish white, Smooth, uniform, lustrous appearance

Wool
Protein (NATURAL)
Creamy white or white color or pale yellow to brown color acc. To breed. Natural Luster. English Wool has mote luster than Merino Wool. Natural Crimp is present in Wool Coarser fibers have darker and finer have light color. Finer have 30 twist/inch and coarser have 2 to 3 twists per inch

Silk
Protein (NATURAL )
2 continuous filament cemented by sericin gum. In raw formRough and off white, low luster. Degummed Silk-more luster and shine. Degummed silk white and semi transparent color. Finer fiber in center of cocoon. Sericin b/w two filaments .Silk has rough surface and cracks in its sericin layer

Jute
Cellulose (NATURAL)
Yellow to brown and sometimes grey. Natural Silky and Lustrous. Rough and harsh feel Continuous strand form made by number of fibers bound together. Bound by gummy material called as Lignin.

Sisal
Cellulose (NATURAL )
Sisal Fibers have 6% lignin and 94% cellulose If processing is done correctly then creamy white with a good luster

Asbest os
Mineral (NATURAL)
Occur in crystalline form

Polyester
Polymer (MAN MADE)
Colorless and partially transparent It has smooth and glass like structure

Structur e& Appeara nce

Appearance depends on

Convolutions are important For spin ability

Fair luster. Can be increased by Mercerizat ion

Retting. Dew Retting can cause a black or grey coloring of fiber

Smooth shiny and regular surface resembling Glass fibers

Luster improves when impurities are improved

Jute fiber contains 20% Lignin

Individual fibers are bound by natural gum

Little luster can be reduced by adding delusturant Titanium Dioxide (TiO2) during production

Mineral obtained in form of silicates Polyester fiber are manufactu red in variety of counts and staple lengths Crystals – No limit to the fibers

Diameter of Cotton ranges to 12 to 20 microns

Sometimes 30 Microns

Mean diameter is about 20 microns(0.02mm)

Epicuticle has thickness of 10-10 m Epithelial layer has avg thickness of 0.05 to 0.5 microns

Retting sometimes destroys the cells giving a hairy appearance to it.

Harder as compared to Bast fibers

Fine Structur e
Individual cotton fiber has two walls Primary & Secondary

Diameter of flax varies at different points

Individual fiber length ranges from ¾ to 3 inches
Average Length of strand is 8 to 24 inches

Finest Coarser fibers have fibers have 2000 700 scales scales per per inch inch Avg length of Cortex is 80 to 110 microns, width is 2 to 5 microns and thickness is 1 to 3 microns Fiber length of wool fiber is 1.5 to 15 inches Fine wools have 1 to 1.5 inches Longer are coarser and Shorter are finer
Medium have 2.5 to 6 inches

Combined form give oval shape to the silk strand

But retting doesn’t separate individual fiber from each other Continuous strand Form Leaf Fiber

Polyester is also available in micro denier (0.7) form called as micro fiber

In beginning its coarser ,and in end its becomes finer

Fine and lustrous shine on fiber, when lignin is removed

Shiny surface with smooth texture

In strand form (3 feet)

Strand of raw silk of diameter 0.178mm Degummed silk has diameter of 0.0127 mm. Length of Silk strand is 1 to 2 Km

Individual fiber 0.1 inch

=

Strand form length is about 2 to 4 feet Individual Fiber Length is about 0.1 inch. Cannot be used in individual form

Fiber Length

1.5 inch (Pakistan)

2.5 to 3 inch (Egypt) But after breaking and scutching the length becomes 16 inches

Length of Asbestos Fiber varies from 0.5 to 15 inches

Different fiber length can be achieved in multi filament, monofilament and short staple

Length of Jute in strand form is 7 feet Mean diameter of individual jute fiber is about 0.022 mm

Coarser have 5 to 15 inches of length

Fine fiber as micro fiber can be made with its extra fine properties

Specific Gravity

1. 54

1. 54

1.32

Degummed silk has 1.25. Raw silk has 1.5 Good moisture absorbency. Under (std Cond.) it regains 11%. Under humid
conditions regains

1.5

1.5

Polyesters in which Titanium dioxide is used have1.40. Most Polyesters have 1.38 and modified have

1.25 -1.50
Under Normal condition , it has moisture regain of 13.75% Very low moisture regain of 0.4% at (std Cond.) It doesn’t absorb water Strength decreases by 10 to 15% when it is in wet condition Under humid condition s regain of 23/% approx same to cotton Strength decreases in wet form in the presence of salt in water. The product gets heavy when its wet Bad conductor of heat. Most outstanding property. Resistant to heat at even high temperatures. Its doesn’t burn or catch fire or melt When exposed to temperature above 300oC can turn red Quick drying property. Good wash ability Even at 100% humidity its moisture regain is only 0.6 – 0.8% Low moisture absorption generates more static electricity in the fibers

Absorbs moisture from atmosphere.

At 65% humidity, moisture regain of 8.5%

Moisture regain of 12%. More than cotton

Wool absorbs more moisture than any other fiber. Under Std Conditions , moisture regain of 16 to 18%

Effects of Moisture
strong 20% in wet state 100% humidity, regain of 20% to 25% 20% strong in wet conditions

35%. Strength decreases by 15 to 25% when it’s wet. Can also absorbs salts in nature. This property helps in the processing of increasing the weight of fabric.

Great affinity of absorbing moisture

Absorbs moisture readily

Wool can regain 35% of moisture from air. In wet state strength of wool decreases but its volume increases by 10%.Hot water damages wool. it looses its elasticity & becomes completely. At 120oC water dissolves wool. By absorbing water, wool releases heat.

Thermal Properti es

Good resistant to heat. At 120oC, small visible change is seen

At 150oC, decomposes more quickly, at 240oC, it readily decomposes

Resistant to heat. At 120oC its color starts to change before it decomposes. Good conductors of heat therefore, they are used in hot countries like Pakistan

Good resistance to heat. At 100oC wool softens. At 130oC it decomposes and turns yellow. At 300oC it burns giving smell burning feathers. Wool burns in flame and when its removed, its stops burning

Burns giving paper like smell leaving Ash

Withstands higher temperature in comparison to wool. At 140oC, it remains unaffected. At 175oC it decomposes and gives smell of burning hairs.

Good insulator of heat

Good insulation, because of air pockets

Since its thermopla stic it melts and form beads

Melting point is 238-290oC

Ability of trapping air inside

Air permeability is good

15% strength is lost when prolonged exposure at 150o C and 50% at 185oC

Effect Of Sunlight

Loss of strength

Photo degradation is accelerated in the presence of Moisture

Slightly effected by sunlight

Its strength gradually decreases

Keratin present in wool decomposes in presence of sunlight. Sulphur present in wool is converted to H2SO4 and .discolors wool

Highly resistant to chemicals

Attacked by hot(dil) and Cold(conc.) acids

Can withstand cold dilute acids. However hot (dil) and cold (Conc.) acids damage it.

Wool is only attacked by hot sulphuric acid and nitric acid Wool is dissolved in caustic soda solution.

Keratin is sensitive to most of the .Alkalis Great care is taken when wool is washed is treated by detergents.

Chemical Propertie s

Not attacked by cold dilute acids. Excellent resistant to alkalis.

Resistant to Alkalis. Its difficult to bleach b/c of its hard surface

Cupra-Ammonium hydroxide and cupriethylene diamine can dissolve cotton(Organic Solvents) After 50 years of storage it doesn’t show loss in strength

Not effected by organic solvents

Has good resistance to organic solvents, such as dry cleaning agents and solvents

Less photo degradation as compared to wool. No Sulphur. Attack by atmospheric oxygen with sunlight causes lost in strength Cold dilute acids (No). Hot dilute (YES) Concentrated acids can attack Fibroin of Silk and damaging amino links. Moderate conc. Acids can cause contraction in Silk, used as creped fabrics. Organic solvents attack the surface. Alkalis destroy Bringing more crushed than appearan ce called wool. as NaOH Scroop. dissolv es Silk As the time passes atmospheric oxygen destroys its strength.

Gradual loss of strength when exposed to sunlight

Loss in strength when its exposed to sunlight for a long time

Sunlight has no effect on asbestos. Atmospheric oxygen also doesn’t effect Asbestos

Good resistance to sunlight, better than Nylon. On prolonged exposure, photo degradation occurs, but doesn’t become yellow. UV light destroys inner hydrogen bonds

Cold weak acids does not harm the fiber

Hot weak and cold (conc.) acids destroy the fiber Sodium Hydroxi de, Soda Ash and bleachi ng agents not recomm ended

Cold weak acids doesn’t harm it, hot weak and cold (conc.) can destroy the fiber Highly resistant to chemicals, acids and organic solvents and commonly used textile chemicals at high concentrations

Good resistance to string acids at room temperature but hot strong acids can destroy polyester Not affected by weak Alkalis at room temperature. Its not dissolved by most of the Organic Solvents. Not affected by dry cleaning agents Strong Alkalis destroy polyester at room temperature and degrade it at high temperatures

Very sensitive to most of the Alkalis

In most of the cases it’s not bleached because it’s used for rope. If they are bleached they are bleached with low PH alkaline solution

Effect Of Age

Can be stored for long time

Can be store for long time

Shows little loss in strength after a long period of storage

Good age resistance. Its used for storage and gradually can be stored for log time

Good age resistance.

Extremely resistant to aging. Can be stored for long period of time without any loss in strength

As it’s a man made fiber its age factor is excellent.

Resistanc e to Micro Organism s Resistanc e To Insects

Attacked by Fungi, Mildew can feed on cotton and make it weak

Microorganism attack can increase in humid conditions. Resistance increases in pure bleached form. Mildews can attack it in unbleached form Fiber is highly resistant to the attack of insects

Wool has poor resistance to microorganisms. Mildew and fungi can attack and damage wool. This is due to Keratin serves as food

Better resistant than wool fibers

Good resistance to microorganisms

Microorganisms destroy it when its for long period of time Good resistance to insects when Lignin is removed

Not at all attacked by Microorganisms

Mildew neither discolors nor weakens polyester. Good resistance

Its not attacked by Insects

Insects damages Wool

Can be attacked by insects and microorganisms

Bleaching and scouring increases the resistance removes lignin

Not attacked by insects

Insects can attack food stains on the fabric, damaging fibers

Alamgir Khan® (08-TE-07)

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