Lesson: Fibre to Fabric

Type 1 MathType@MTEF@5@5@+= feaagKart1ev2aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqr1ngB PrgifHhDYfgasaacH8YrFr0lbbf9q8WrFfeuY=Hhbbf9v8qqaqFr0x c9pk0xbba9q8WqFfea0=yr0RYxir=Jbba9q8aq0=yq=He9q8qqQ8fr Fve9Fve9Ff0dmeaabaqaciGacaGaaeqabaWaaeaaeaaakeaaieqaju gGbabaaaa8cCBapeGaa83eGaaa@3AF5@ Very Short Answer Questions (7 Q)

Question: 1

From which part of the sheep’s body is wool obtained?

Solution:

Fleece

Question: 2

What does rearing involve?

Solution:

Rearing involves providing suitable food and selective breeding of animals that produce wool.

Question: 3

Which process involves cleaning of the sheared skin with hair?

Solution:

Scouring

Question: 4

What is health risks faced by workers in any particular industry called?

Solution:

Occupational hazards

Question: 5

In which stage of its life cycle does a silkworm yield silk?

Solution:

Cocoon stage

Question: 6

What is the name of the process that involves taking out threads from cocoons to make silk?

Solution:

Reeling of silk

Question: 7

Which two countries are the largest producers of silk in the world?

Solution:

China and India

Type 2 MathType@MTEF@5@5@+= feaagKart1ev2aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqr1ngB PrgifHhDYfgasaacH8YrFr0lbbf9q8WrFfeuY=Hhbbf9v8qqaqFr0x c9pk0xbba9q8WqFfea0=yr0RYxir=Jbba9q8aq0=yq=He9q8qqQ8fr Fve9Fve9Ff0dmeaabaqaciGacaGaaeqabaWaaeaaeaaakeaaieqaju gGbabaaaa8cCBapeGaa83eGaaa@3AF5@ Short Answer Questions (7 Q)

Question: 1

What is sericulture?

Solution:

Rearing silkworms to obtain silk threads is known as sericulture.

Question: 2

Why is selective breeding important in animal farming?

Solution:

Selective breeding is important in animal farming to get special and desired characters in the offspring. For example, in sheep, selective breeding ensures breeding of sheep with soft under-hair. This ensures higher production of good quality wool.

Question: 3

Name the steps that involve making wool from sheep’s fleece.

Solution:

The steps that involve making wool from sheep’s fleece are:

(i)                 Shearing

(ii)              Scouting

(iii)            Sorting

(iv)             Removal of burrs

(v)               Dyeing

(vi)             Straightening, combing, and rolling into yarn

Question: 4

Why the fibres obtained from sheep have to be dyed?

Solution:

The fibres obtained from sheep have to be dyed in various colours as the fleece of sheep and goats naturally vary between black, brown, or white colours only.

Question: 5

Why is shearing done in summer/hot months only?

Solution:

Shearing involves removal of hair from the sheep’s body. The hair traps a lot of air to keep their bodies warm. If they were sheared during winter, the sheep will die due to lack of warmth in the absence of protective hairy covering that traps the body warmth.

Question: 6

What are the four stages in the life history of a silkworm?

Solution:

The female silk moth lays eggs, which hatch to form the caterpillar or larva. The caterpillar which is a voracious eater grows large by feeding on leaves, and is soon ready for the next stage known as the pupa. The caterpillar secretes a silk fibre that forms a cocoon around it and turns into a pupa. The adult moth slowly develops inside this cocoon, and once fully formed, breaks out to fly away.

Question: 7

What are the various types of wool?

Solution:

Besides sheep wool, we have yak wool popular in Ladakh and Tibet. In Kashmir, the under fur of goats is used for weaving the famous pashmina shawls. Angora wool is obtained from angora rabbits, while the angora goats give mohair wool. Fur from camels also produces wool, while llama and alpaca in South America also yield wool.

Type 3: Long questions (6 Q)

Question: 1

Explain rearing of sheep.

Solution:

In the wool industry, the first step begins with the effective rearing of sheep and other wool giving animals. In the Himalayas, or in the North Indian plains (that include Gujarat, Rajasthan, Haryana, and Punjab), it is a common sight to see herds of sheep being taken around for grazing, which involves eating grass and leaves. Apart from this, rearers also supply the animals with a mixture of minerals, pulses, jowar, oilcakes and corn. In winter, when the sheep cannot be taken outside for grazing, they are fed on dry fodder, grains, and leaves. In India various breeds of sheep are reared in different parts of the country that give us different varieties of wool with varying qualities. Some sheep breeds show thick coat of hair that yields good quality wool in large quantities, and these varieties of sheep are chosen for selective breeding to produce offspring with good quality hair. After the sheep have developed a thick coat of hair, it is shaved off generally during the summer months, to get wool.

Question: 2

Give diagram of the lifecycle of a silk moth.

Solution:

Question: 3

Discuss the steps involved in making wool from fibres.

Solution:

Step 1: When the sheep’s hair is thick and grown, it is ready for cutting. The fleece along with a thin layer of the dead upper skin is removed. This is known as shearing, and it is done during the summer months.

Step II: The sheared hair with the attached skin is next washed thoroughly to remove grease, dirt, and dust. This process is termed scouring.

Step III: Then the sheared skin and hair are sent for segregation of hairs based on textures. This process is termed sorting.

Step IV: Next step involves the removal of small fluffy fibres known as burrs from the hair. After the burr removal, the fibres are further scoured and dried. Here the wool becomes ready to be turned into fibres.

Step V: Next the fibres are dyed in different colours.

Step VI: In the last step the dyed fibres are combed, straightened, and rolled into yarns and are made ready for weaving.

Question: 4

Explain how silk is obtained.

Solution:

A female silk moth lays a large number of tiny eggs. These eggs are stored in paper or cloth strips and sold to farmers who rear these eggs under suitable temperature for them to hatch. When the eggs hatch to produce larva, they are kept in trays containing mulberry leaves. The larva eats the leaves voraciously, and rapidly grows in size. After about a month the caterpillar stops eating and is placed in a small bamboo chamber containing a twig where it starts spinning the cocoon around itself. When the spinning is over, a pile of cocoons is collected. These are boiled, steamed, or dried in the sun, and the silk fibres are then separated. The process of separating the silk threads from the cocoon is known as reeling of silk, and the silk fibres obtained through reeling are used by weavers to create silk fabrics.

Question: 5

What are the different varieties of silk available in India?

Solution:

The silk thread is obtained from the cocoon stage in the lifecycle of the silk moths. There are different varieties of silk moths that look different from each other. The threads produced by the cocoons of these different varieties of silk moths are also different in texture, and vary from smooth, to shiny, to coarse. The well-known silk varieties in India are the eri silk, tassar silk, mooga silk, and kosa silk, among many more, and these types are produced from the cocoons spun by different varieties of silk moths. The most common silk moth in India is the mulberry silk moth and the fibre produced by it is of a lustrous, elastic, and soft variety of silk.

Question: 6

What is the folklore behind the discovery of silk in China?

Solution:

While the exact history of the discovery of silk is not known, according to folklore, the Chinese empress Si-lung-Chi was looking for a reason for the damaged mulberry leaves in her garden. She noticed a number of white worms devouring the mulberry leaves, and some of these worms were spinning shiny cocoons around themselves. When a cocoon fell into her tea accidently, the delicate silk threads separated from the cocoon, and silk was discovered. The silk industry then started in China, but was kept a secret. Later, for many centuries, travellers and traders carried silk to other foreign countries, and the road through which they travelled became famous as the ‘silk route’.