SYNTHETIC FIBRES AND PLASTIC 1. Clothes are made of fabrics. 2. Fibres can be natural or manmade. 3. Fabrics are made up of yarns arranged at right angles to each other. 4. Yarns are made up of very thin strands called fibers by spinning. 5. The fibres which are obtained from plants and animals are called natural fibres. 6. Cotton, jute, coir, hemp, lines are natural plant fibres. Linen is a plant fibre obtained from flax plant. 7. Wool, silk are natural animal fibres. 8. Wool is obtained from the fleece of sheep and goat, hair of rabbits, yak and camels. 9. Silk fibre is drawn from the cocoon of silk warm. 10. Cotton and jute are obtained from plant source. They are cellulose fibres. 11. Wool and silk are obtained from animal source. They are protein fibres. 12. Fibres prepared from petrochemicals are called synthetic fibres. 13. Artificial fibres are of two types; synthetic fibres and regenerated fibres. 14. Polyester, Nylon, Acrylic, olefin are synthetic fibres. 15. Polyester, Nylon, Acrylic, olefin are truly synthetic fibres made from coal and petrochemicals 16. Rayon, Cellulose acetate/Acetate rayon are regenerated fibres made from wood as raw material. 17. Regenerated fibres are called Cellulosic fibres. 18. Rayon, Cellulose acetate/Acetate rayon are regenerated fibres. 19. Both synthetic fibres and regenerated fibres are artificial fibres. 20. Plastics can be thermoplastic or thermosetting in nature. 21. Thermoplastic can be melted, remoulded and recycled as many number of times by heating. 22. Polyester, Nylon, Polythene and PVC etc are example of thermoplastic. 23. Thermosetting plastics once set can not be remoulded again. 24. Example of thermosetting plastic is bakelite and melamine. 25. Cellulose is made up of a large number of glucose units. 26. All fibres and plastics are made of long chains called polymers. 27. The term polymer comes from two Greek words ’poly’ means ‘many’ and ‘mer’ means ‘part ‘or ‘unit.’ 28. Polymers are made up smaller units joined together to form long chain. 29. Cotton is a polymer called cellulose. 30. Nylon is the first fully synthetic fibre. It was discovered by Wallace Carothers in 1935. 31. Socks, ropes, tents, tooth brush, car seat belts, sleeping bags, curtains are made from Nylon. It is also use for making parachutes and ropes for rock climbing. 32. A nylon thread is stronger than a steel wire. 33. Rayon is the first commercial regenerated silk. 34. Rayon is also known as artificial silk. 35. Terylene is popular polyester. 36. PET is from of polyester and used for making bottles, utensils, films, wires etc. 37. Polyester ( Poly + Ester) is made up of the repeating units of an ester ( a chemical) 38. Esters are the chemicals which give fruits their smell. 39. Fabrics made from polyester fibre do not get wrinkled easily. 40. Acrylic fibres resemble wool. 41. Reduce, Reuse, Recycle and Recover is called the 4R principle. 42. Polycot is a mixture of polyester and cotton. 43. Polythene is an example of plastic. 44. Teflon is a special plastic on which oil and water do not stick. It is used for non-stick coating on cookwares. 45. The uniforms of firemen have coating of melamine plastic to make them flame resistance. 46. A material which gets decomposed through natural processes, such as action by bacteria is called biodegradable. 47. A material which is not easily decomposed through natural processes is called non-biodegradable. 48. Nilon-2 and Nylon-6 are biodegradable polymers. 49. Fibres become yarn or thread by spinning, thread or yarn become fabric by weaving or knitting and fabrics become clothes by stitching. 50. Cellulose acetate or acetate rayon is a regenerated fibre made from cotton linters combined with acetic acid. 51. Though Rayon is an artificial fibre but it has a plant origin. 52. Terylene, Decron and Terene are some polyester fibres. 53. Acrylic wool is not attacked by moth whereas natural wool is.
Classification of fibres: Fibres can be classified on the basis of:
the source of origin
the units of which they are formed
Classification based on the Source of Origin Fibres can be classified as Natural fibres and artificial fibres.
Natural fibres: The fibres which are obtained from plants and animals are called natural fibres. Natural fibres obtained from plants are cotton, jute, coir, hemp, lines. Natural fibres obtained from animals are silk and wool. Artificial fibres: The fibres which are synthesized in industry from simple chemicals obtained from petroleum are called synthetic fibres. Polyester, Nylon, Acrylic, Olefin, Polyester, Nylon, Acrylic are artificial or manmade fibres. Artificial fibres are of two types; Synthetic and regenerated. Synthetic fibres: Synthetic fibres are made entirely from coal and petrochemicals. Synthetic fibres are usually stronger than either natural fibres or regenerated fibres. Polyester, Nylon, olefin and Acrylic are synthetic fibres. Nylon is the first fully synthetic fibre. Regenerated fibres: Regenerated fibres are made from raw materials that form fibres naturally, for example, wood pulp or cotton linter. These raw materials are reformed to produce fibres suitable for making into yarns. Regenerated fibres are also called Cellulosic fibres as these are derived from cellulose. Rayon and acetate are two important regenerated fibres.
The units of which they are formed:
Cellulose is a natural polymer. It is made up of a large number of glucose units joined together to make a long chain. Cotton, rayon, jute, linen, hemp etc are cellulose fibres. Actually the plant fibres contain cellulose. Though rayon is an artificial fibre it has a plant origin.
Nylon is the first synthetic fibre. It is a polyamide fibre, containing many amide units repeated to form a long chain. Amides are a class of chemicals which are also present in protein.
Polyester fibres have a large number of esters present as repeating units to form long chains. One chain may contain thousands of ester units. Ester is a class of chemicals which are also responsible for the typical smell of each fruit.
Acrylic fibres: Acrylic fibres resemble wool in its properties. It is soft, light weight and wool-like in finish. It is capable of trapping air and hence keeps body warm. Most of the shawls, blankets and sweaters are made from acrylic.
RAYON: Rayon has a silky texture (touch) . Therefore, rayon is called artificial silk. It is the first commercial regenerated synthetic fibre. It is made from cellulose obtained from wood pulp. Hence, it has a plant origin.
Uses of Rayon: Rayon is used
· in textile industries for making fabrics. · in the manufacture of carpets, tyre cord. · for making bandage and surgical dressing.
NYLON: Nylon was the first synthetic fibre. It was discovered by Wallace Carothers in 1935.The name Nylon was derived from New York (NY) and London (LON) as it was produced in New York and London almost at the same time. It resembles silk and wool. It is a polyamide fibre, containing many amide units repeated to form a long chain. Amides are a class of chemicals which are also present in protein.
Use of Nylon: Nylon is used in
· in textile industries for making fabrics/sarees/neck ties/socks/elastic hosiery. · in the manufacture of tyre cord, ropes · making fishing net and parachute ropes/ tooth brush, car seat belts, sleeping bags, curtains.
Properties of Nylon: · Nylon fibres are very strong. · Nylon fibres are elastic. · Nylon can be drawn into very thin fibres. · Nylon is wrinkle (fold) resistant. · Nylon is abrasion (scratch) resistant. · Nylon is not attacked by fungus, moth etc. · Nylon is insoluble in all common solvents. POLYSTER Terylene, Decron and Terene are some polyesters fibres. Polyesters are made from petrochemicals. Polyester fibres have a large number of esters present as repeating units to form long chains. One chain may contain thousands of ester units. Ester is a class of chemicals which are also responsible for the typical smell of each fruit.
Uses of polyesters: Polyesters are used · For manufacturing sarees, dress materials, curtain cloth etc. · For making blends with other fibres e.g. Terylene with cotton gives terycot, with wool it gives terywool. Clothes made from blends are more comfortable to wear.
Properties of polyesters: · Polyester fibres are quite strong. · Polyester fibres absorb very little water. So they dry quickly. · Polyesters are wrinkle resistant.