1. Why is acrylic more popular than wool?
2. What is the difference between natural
and synthetic fibres?
3. Write a few characteristics of synthetic
fibres.
4. What is 4R principle?
5. What are biodegradable and non-
biodegradable materials?
6. What are the disadvantages of plastics?
7. Why is it convenient to store plastic
containers than metals?
8. What are the uses of nylon?
9. What do you mean by synthetic fibres?
10. Why is it advisable to not wear synthetic
clothes while working near fire?
Answers
1. The wool obtained from natural sources is quite expensive ,whereas clothes made from acrylic are relatively cheap. Though they couldn't absorb moist and sweat ,they are of good quality for fashionable clothes. They are more durable and affordable which makes them more popular than natural fibres.
2. Natural fabrics, like merino wool, cotton, cashmere, and silk, are made of fibers that are produced by animals and plants. Synthetic fabrics, like polyester, nylon and acrylic, are "man-made" fibers that are created in laboratories.
3. Characteristics of Synthetic Fibres
•Synthetic fibres are cheaper than natural fibre.
•Synthetic fibres are stronger than natural fibre.
•Synthetic fibres are more durable than natural fibre.
•Synthetic fabrics are dried up in less time.
•Synthetic fibres are easy to maintain and wash.
4. A number of waste prevention techniques are available, and they are commonly summarized as the so-called 4Rs: reduction, reuse, recycling and recovery. Reduction, reuse and recycling are known in the industry as the 3Rs.
5. Biodegradable substances are those that degrades or break down naturally.Materials like plants, animals, their waste, paper, fruits, flowers, vegetables fall under biodegradable substances, on the other hand, rubber, plastic, chemicals, paint plastic falls under the category of the non-biodegradable items.
6. The demerits of plastic are:
1) Plastic bags thrown carelessly on roads get into drains and the sewer system and choke them. As a result sewage water spills on road and causes spread of diseases.
2) Plastics give out harmful gases upon heating or burning which causes air pollution and many health problems.
3) Plastic bags filled with garbage is thrown away in the open. When stray animals look for food in these bags, they swallow plastic bags along with food.
7. It is so because plastics are non corrosive in nature and on the other hand metals react with oxygen water and sometimes form hydrogen. that's why it is convenient to store products in plastic containers rather than using metal containers..
8. Uses of Nylon
•Clothing – Shirts, Foundation garments, lingerie, raincoats, underwear, swimwear and cycle wear.
•Industrial uses – Conveyer and seat belts, parachutes, airbags, nets and ropes, tarpaulins, thread, and tents.
•It is used to make a fish net.
•It is used as plastic in manufacturing machine parts.
9. Synthetic fibers (or synthetic fibres in British English; see spelling differences) are fibers made by humans through chemical synthesis, as opposed to natural fibers that are directly derived from living organisms. These are called synthetic or artificial fibers.
10. Synthetic fibers melt on heating. If they catch fire, they melt and stick to the body of the person wearing them. This is why it is advised not to wear clothes made of synthetic fiber while working in a kitchen or in a fire laboratory.