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Text A. Chemical fibres

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1. All fibres are classified intonatural and man-made fibers. Man-made or chemical fibres are of great industrial importance; their importance increases as time goes on.
Man-made fibres
are classified into three classes: those made from natural polymers, those made from synthetic polymers and those made from inorganic materials. 2. Fibres from Natural Polymers.Cellulose (natural polymer) contained in the wood pulp or cotton is once solved with chemicals and then regenerated into fibres.

The most common chemical fibres are rayon fibers. The rayon fibres are produced from wood pulp as a raw material and are constituted of cellulose just as cotton and flax fibers. Rayon fibres are superior in moisture and water absorbency, and are dyed deeply and colorfully with a variety of dyestuffs. The rayon fabrics are evaluated as fashion clothing.
3. There are two types of rayon fibres, i.e., filament yarns and staple fibers. Filament yarns are used for fabrics for women's clothing and linings. In addition, flat filament yarns are used for raw materials for hats and handicraft yarns. Staple fibres are used for fabrics for women's clothing, curtain, textile wall-covering, wrapping paper for cakes, etc.

Rayon fibres are rather weakened by wetting so people should avoid hard rubbing during the laundering. 4. Fibres from Synthetic Polymers are fibres manufactured from products artificially synthesized from petroleum as raw materials. There are very many synthetic fibres. The most common are polyester, polyamide (often called nylon), acrylic, elastane (or spandex in the USA), polyethylene, polyurethane, vinylon and others.

5. Polyester fibresare manufactured most abundantly among synthetic fibres. The amount of production is continuing to increase year by year. Polyester fibres have such features as extreme strength, resistance to crease, less moisture absorption, thermo-plasticity, and resistance to acid.
6.In polyester fibres, both filament yarn and staple fibres are manufactured in nearly equal quantity. Filament yarns are woven or knitted as they are. In addition, they are knitted into jersey or woven into fabrics of textured yarn by combining with other types of filament yarns. The staple fibres are friendly with other types of fibres. They are manufactured into fabrics, by blending with cotton, wool and linen fibres, making the use of each characteristic.

7. Nylon fibresare the fibers having the longest history among synthetic fibres. They are used for a variety of uses from clothing to home furnishings and industrial uses.
In nylon fibres, there are many types depending on the raw materials: "Nylon 6" fibres, "Nylon 66" fibres, etc.
Comparing other synthetic fibres with nylon, scientists point out great advantages of nylon fibres: resistance to abrasion and flexing, resistance to chemicals and oil, non-attackable by sea water. Nylon fabrics should be ironed at the low temperature. Almost all nylon fibres are filament yarns ranging from very fine to coarse and may be used for clothing such as sport wear, lingerie; home furnishing as carpets; and industrial uses such as fishing nets, ropes, and tire cords.

8. Acrylic fibreshave characteristics most similar to those of wool fibres. They are soft and light fibres having light and warm tactile feeling to the human skin. Acrylic fibres are widely used for knitted products such as sweater and jersey; bedding textiles such as blankets and sheets, carpets for home-uses.

9. Acetate filament yarnsare referred to as "Fibers of Beauty", because they have luster and tactile feeling as silk fibres. The quantity of production in Japan is not so large, but in the USA large quantities of acetate filament yarns are used for apparel manufacturing. Acetate filament yarns are same as rayon fibres in those points that pulp is used as main raw material. However acetic acid is reacted chemically, thus, acetate filament yarns have characteristics of both vegetable fibers and synthetic fibres.

Acetate fibres are frequently used for women’s dresses and exhibit their beauty in the form of women's formal wear, suits, coats or knitwear.
10. Fibres from Inorganic Materialsare the inorganic chemical fibres made from materials such as glass, metal, carbon or ceramic. These fibres are very often used to reinforce plastics to form composites.

11. Glass fibresare formed from a special glass both in filament yarns and staple fibres. Staple fibres are used for architecture, vehicles, shipping, space ships, refrigerators, etc. By contrast, because filament yarn can be woven, filament yarns are used for electric insulating material or flame retardant.

12. Carbon fibres have many advantageous characteristics such as very light weight, high strength and elasticity, excellent heat resistance, electrical conductivity, and resistance to chemical agents. Carbon fibres are mainly used for reinforcement materials for plastics.

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