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Synthetic fibers have some properties superior to natural including: high strength, excellent chemical resistance, resistance to moth and decay. Synthetic fibers have properties which natural fibers do not have them: non flammable, resistant to high temperatures, etc.. They have though some unsatisfactory properties: low moisture absorption, high electrostatic charge, pilling effects ,they can be colored with difficulty.
In the last period of time fiber spinning is very used .Spun fibers have two structures: "shell-core" and "side by side" .
Shell-core fibers have a core of a polymer that gives to the fiber strength, elasticity, etc.,and a shell of another polymer for lowering static load, increasing the gloss effect, pilling reducing etc.
Structure "side by side "may, for example, give a wrinkle larger effect to fiber, if the two polymers have different contractions.
Although almost half of the wool fabric washing resistant products in the world today are obtained by oxidative proccess, it tends to be quickly replaced by treatment with polymer, which has the advantage of completely eliminating the degradation of fiber.
Application of polymer is made in two ways. One requires spraying a thin layer of plastic on each fiber, to mask scales and to allow free movement, back and forth, of the wool fibers. Thus,at the washing, they may return to starting position, preventing fabric pilling.
The second method of treating the polymer has an opposite principle to the first. It provides attachment of fibers in fabric, using microscopic plastic decks, each other, to prevent them moving and get entangled.
So far, there have been tested several types of polymers for this operation. Most appropriate are those which contain groups enabling the formation of chemical bonds between molecular chains, making, after application, insoluble resin bridges, but soft and elastic, which eliminate the danger that the fabric to become rigid .
Most synthetic fibers are polymer-based, and are produced by a process known as spinning. This process involves extrusion of a polymeric liquid through fine holes known as spinnerets. After the liquid has been spun, the resulting fibers are oriented by stretching or drawing.
This increases the polymeric chain orientation and degree of crystallinity, and has the effect of increasing the modulus and tensile strength of the fibers. Fiber manufacture is classified according to the type of spinning that the polymer liquid undergoes: this may be melt spinning, dry spinning, or wet spinning. Melt spinning is the simplest of these three methods, but it still requires that the polymer constituent be stable above its melting temperature. In melt spinning, the polymer is melted and forced through the spinnerets, which may contain from 50-500 holes.
A new wave development in science is something known as Frozen Smoke. It is actually a substance called Aerogel. Aerogel is a light weight solid that can filter waste. It is very absorbent like a massive sponge only smaller. It is able to absorb large quantities of liquid. It is made up of silica.
Aerogel has been used to clean up oil spills. It works better than conventional methods because of its capacity to absorb such large volumes of the liquid. Aerogel also absorbs toluene and other organic compounds that end up in waste water usually industrial plants.
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