Thermal insulation

Published on January 2017 | Categories: Documents | Downloads: 53 | Comments: 0 | Views: 326
of 2
Download PDF   Embed   Report

Comments

Content

Thermal insulation.txt Thermal insulation is the reduction of heat transfer (the transfer of thermal energy between objects of differing temperature) between objects in thermal contact or in range of radiative influence. Thermal insulation can be achieved with specially engineered methods or processes, as well as with suitable object shapes and materials. Fiberglass insulation is commonly found in air ducts, pipes, roofs, walls and floors. Glass wool (UK) or fiberglass insulation (US) is an insulating material made from fibres of glass (fiberglass) arranged into a texture similar to wool. Glass wool is produced in rolls or in slabs, with different thermal and mechanical properties. Manufacturing process:After the fusion of a mixture of natural sand and recycled glass at 1,450 °C, the glass that is produced is converted into fibers. It is typically produced in a method similar to making cotton candy, forced through a fine mesh by centripetal force, cooling on contact with the air. The cohesion and mechanical strength of the product is obtained by the presence of a binder that “cements” the fibers together. Ideally, a drop of bonder is placed at each fiber intersection. This fiber mat is then heated to around 200 °C to polymerize the resin and is calendered to give it strength and stability. The final stage involves cutting the wool and packing it in rolls or panels under very high pressure before palletizing the finished product in order to facilitate transport and storage. Uses:Glass wool is a thermal insulation that consists of intertwined and flexible glass fibers, which causes it to "package" air, resulting in a low density that can be varied through compression and binder content. It can be a loose fill material, blown into attics, or, together with an active binder sprayed on the underside of structures, sheets and panels that can be used to insulate flat surfaces such as cavity wall insulation, ceiling tiles, curtain walls as well as ducting. It is also used to insulate piping and for soundproofing Cellulose can be found in attics, walls, ceilings and other places around the home. It's mostly made of shredded newspaper, which makes it quite combustible. Although cellulose insulation is generously treated with fire retardant, it isn't fireproof. Cellulose installation also absorbs and retains moisture. If soaked, its thermal performance can be permanently diminished. Polystyrene(thermocole) is a transparent, colorless thermoplastic. It's commonly used to make foam board, concrete block and loose-fill insulation. Polystyrene (PS) (pron.: /?p?li'sta?ri?n/) is a synthetic aromatic polymer made from the monomer styrene, a liquid petrochemical. Polystyrene can be rigid or foamed. General purpose polystyrene is clear, hard and brittle. It is a very inexpensive resin per unit weight. It is a rather poor barrier to oxygen and water vapor and has relatively low melting point.[4] Polystyrene is one of the most widely used plastics, the scale of its production being several billion kilograms per year.[5] Polystyrene can be naturally transparent, but can be colored with colorants. Uses include protective packaging (such as packing peanuts and CD and DVD cases), containers (such as "clamshells"), lids, bottles, trays, tumblers, and disposable cutlery.[4] As a thermoplastic polymer, polystyrene is in a solid (glassy) state at room temperature but flows if heated above about 100 °C, its glass transition temperature. It becomes rigid again when cooled. This temperature behavior is exploited for extrusion, and also for molding and vacuum forming, since it can be cast into molds with fine detail. cork is an impermeable, buoyant material, a prime-subset of bark tissue that is harvested for commercial use primarily from Quercus suber (the Cork Oak), which is endemic to southwest Europe and northwest Africa. Cork is composed of suberin, a hydrophobic substance, and because of its impermeability, buoyancy, elasticity, and fire resistance. Cork's bubble-form structure and natural fire resistance make it suitable for acoustic and thermal insulation in house walls, floors, ceilings and facades. Kaolinite is a clay mineral, part of the group of industrial minerals, with the chemical composition Al2Si2O5(OH)4. It is a layered silicate mineral, with one tetrahedral sheet linked through oxygen atoms to one octahedral sheet of alumina octahedra.[4] Rocks that are rich in kaolinite are known as kaolin or china clay. The largest use is in the production of paper, including ensuring the gloss on some grades of paper. In April 2008, the US Naval Medical Research Institute announced the successful use of a kaolinite-derived Page 1

Thermal insulation.txt aluminosilicate nanoparticle infusion in traditional gauze, known commercially as QuikClot Combat Gauze.[15] Kaolin is or was also used: in ceramics. It is generally the main component in porcelain. in toothpaste as a light diffusing material in white incandescent light bulbs in cosmetics as paint to extend titanium dioxide (TiO2) and modify gloss levels; for its semi-reinforcing properties in rubber in adhesives to modify rheology.[16] the production of common smoking pipes in Europe and Asia in organic farming, as a spray applied to crops to deter insect damage, and in the case of apples, to prevent sun scald. as whitewash in traditional stone masonry homes in Nepal. The most common method is to paint the upper part with white Kaolin clay and the middle with red clay. The red clay may extend to the bottom, or the bottom may be painted black. as a filler in Edison Diamond Discs.[17] as an indicator in radiological dating since Kaolinite can contain very small traces of uranium and thorium. to soothe an upset stomach, similar to the way parrots (and later, humans) in South America originally used it.[18] More recently, industrially-produced kaolinite preparations were formerly common for treatment of diarrhea; the most common of these was Kaopectate, which abandoned the use of kaolin in favor of attapulgite and then (in the United States) bismuth subsalicylate (the active ingredient in Pepto-Bismol). for facial masks or soap

Page 2

Sponsor Documents

Or use your account on DocShare.tips

Hide

Forgot your password?

Or register your new account on DocShare.tips

Hide

Lost your password? Please enter your email address. You will receive a link to create a new password.

Back to log-in

Close