Synthetic fibres

What are Synthetic Fibres? Their synthesis, types and applications. .

1. Synthetic Fibres Class VIII Science Meeta Goklani

2. What are Fibers? Fibers are the basic units of all textiles . Fibers are put together to form a continuous strand , making a yarn . Yarns are woven or knitted together to make fabrics.

3. Fibres

4. NATURAL FIBRES COTTON FLAX

5. Fibres are Polymers Monomers (Mono = one, mer = unit) Single unit of a substance is called a monomer. Polymers (Poly= many, Mer = units) A polymer is a large molecule made up of chains of repeating basic molecular units called monomers. 

6. POLYMERISATION The process of joining together monomers to form a polymer is called Polymerisation .

7. Synthetic Fibres are Polymers These are called as synthetic fibres because these fibres are synthesised in the laboratory. Man Made Fibres Artificial Fibres

8. Synthetic Fibres Synthetic fibres are man-made fibres . Synthetic fibres are made from different chemicals, hence each kind of synthetic fibres have their own properties. Synthetic fibres are more in length and are long lasting. The only limitation in synthetic fibres is that they are poor absorbents of moisture and they catch fire easily.

9. POLYMER MONOMER Protein Amino Acids Cellulose Glucose Rayon Cellulose Nylon amide Polyester Ester Acrylic Acrylonitrile Polyethene Ethene Poly Vinyl Chloride Vinyl Chloride

10. Rayon First man made fibre . Rayon is prepared from cellulose (wood pulp). Though cellulose is a natural polymer it needs extensive chemical treatment to form Rayon. Hence, it is also considered a semi synthetic fibre .

11. Rayon First Synthetic Fibre Rayon was called artificial silk as it is lusturous . Rayon fibre has the same comfort property as natural fibres . Rayon is recognised by the name viscose rayon in the textile industry. It is cheaper than silk.

12. Process of making Rayon

13. HOW SYNTHETIC FIBRES ARE MADE?

14. Rayon is similar to cotton as they both contain cellulose but it has a shine like silk. Thus, it is also known as Artificial Silk. 1. Rayon is used to make curtains, car upholstery etc. 2. It is used to make carpets. 3. It is used to making surgical dressings. 4. It is used to make reinforced automobiles tyres . Rayon- Artificial silk

15. Nylon First fully synthetic fibre produced by man in 1935. 64 million pairs of nylon stockings were sold in the first year itself. Nylon got its name from the cities of N ew Y ork and Lon don where it was marketed initially. Nylon is a thermoplastic( that melts on heating).

16. Nylon are synthetic fibres made from petrochemicals. The nylons are polyamides with recurring amide groups. They contain carbon, oxygen, nitrogen and hydrogen elements.

17. Properties of Nylon 1. Strong (High Tensile Strength) 2. Light weight 3. Moth Resistant 4. Durable and Long Lasting 5. Elasticity and strechability 6. Cleanliness and Washability 7. Lustrous 8. Affinity to Dye

18. Variation of luster: nylon has the ability to be very lustrous, semilustrous or dull. Durability: its high tenacity fibers are used for seatbelts, tire cords, ballistic cloth and other uses. High elongation and elasticity. Excellent abrasion resistance. Highly resilient (nylon fabrics are heat-set) Paved the way for easy-care garments. Nylon fabrics have low absorbency. Nylon fabrics are smooth, non-absorbent and dry quickly. Dirt doesn’t cling to this smooth fibre , which can be washed easily or can be even cleaned by using a damp cloth.

19. Fishing Nets

20. Ropes- high tensile strength

21. High tensile strength and Elasticity

22. Ropes- Abrasion resistant and strong

23. Nylogrip Tyres

24. Nylo grip tyres

25. Polyester are made of many ester linkages.

26. Polyester Polyesters are a group of synthetic fibres that have properties similar to nylon. Some popular polyester fabrics are terylene , polythene, Tetraphthalate and Acrylon

27. Properties which make it a popular fabric Polyester fabric is strong. Wrinkle resistant. Softer. Easy to wash and dry. Moth and fungus resistant. Resistant to ordinary chemicals. High Abrasion resistant.

28. Blended Fabrics Sometimes natural fabrics like cotton and wool are mixed with polyester(or terylene ) to make blended fabrics. Blended fabrics are fabrics made by mixing or blending two types of fibres . Polycot = Polyester + cotton Polywool = Polyester + Wool They have properties of both natural fibre and polyester.

29. Terycot , for example is a popular fabric used for making dresses. It is a mixture of terylene and cotton. This combination is easier to wear in summer due to its cotton content with all the advantages of synthetic fibre .

30. Uses of Polyester Fabrics Used to make blended fabrics like polycot, polywool which are used to make pants, shirts, suits and other dresses. Polyester is uesd for making sails of sail boats.

31. sails

32. Water Hoses in fire fighting operations Conveyer Belts