how are these animal fibres obtained from their sources.(a) Silk (b) Wool
Answers
Rearing and breeding of sheep :
Apart from grazing sheep, rearers also feed them on a mixture of pulses, corn, jowar, oil cakes (material left after taking out oil from seeds) and minerals and In winter, sheep are kept indoors and fed on leaves, grain and dry fodder.
Sheeps are reared in many parts of our country and Certain breeds of sheep have thick coat of hair on their body which yieldsgood quality wool in large quantities.
Once the reared sheep have developed a thick growth of hair, hair is shaved off for getting wool.
Processing Fibres Into Wool
Wool that is used for knitting sweaters and for weaving shawls is the product of a long process involving the following steps :
Step 1-
The fleece of the sheep along with a thin layer of skin is removed from its body. This process is called shearing.
Usually, hair are removed during the hot weather which enables the sheep to survive without their protective protective coat of hair.
The hair provide woollen fibres and Woollen fibres are then processed to obtain woollen yarn.
Step 2-
The sheared skin with hair is thoroughly washed in tanks to remove grease, dust and dirt. This is called Scouring. Nowadays, scouring is done by machines.
Step 3-
After scouring, Sorting is done. The hairy skin is sent to a factory where hair of different textures are separated or sorted.
Step 4-
The small fluffy fibres, called burrs, are picked out from the hair. The fibres are scoured again and dried and the wool is ready to be drawn into fibres.
Step 5-
The fibres can be dyed in various colours, as the natural fleece of sheep and goats is black, brown or white.
Step 6-
The fibres are straightened, combed and rolled into yarn and the longer fibres are made into wool for sweaters and the shorter fibres are spun and woven into woollen cloth.
Silk fibres are also animal fibres.
Silkworms spin the ‘silk fibres’.
The rearing of silkworms for obtaining silk is called Sericulture.
Life History Of A Silk Moth
The female silk moth lays eggs, from which hatch larvae which are called Caterpillars or Silkworms.
They grow in size and when the caterpillar is ready to enter the next stage of its life history called pupa, it first weaves the net to hold itself and swings its head from side to side in the form of figure eight (8).
During these movements of head, the caterpillar secretes fibre made of a protein which hardens on exposure to air and becomes silk fibre.
The caterpillar completely covers itself by silk fibres and turns into pupa. This covering is known as Cocoon.
Silk fibres are used for weaving silk cloth. The silk yarn (thread) is obtained from the cocoon of the silk moth.
Thus, Tassar silk, mooga silk, kosa silk, etc. are obtained from cocoons spun by different types of moths and the most common silk moth is the mulberry silk moth.
The silk fibre from the cocoon of this moth is soft, lustrous, and elastic and can be dyed in beautiful colours.
Sericulture or culture of silkworms is a very old occupation in India.
From Cocoon To Silk
For obtaining silk, moths are reared and their cocoons are collected to get silk threads.
Rearing silkworms :
A female silk moth lays hundreds of eggs at a time which are stored carefully on strips of cloth or paper and sold to silkworm farmers.
The farmers keep eggs under hygienic and suitable conditions of temperature and humidity.
The eggs are warmed to a suitable temperature for the larvae to hatch from eggs which is done when mulberry trees bear a fresh crop of leaves. The larvae, called caterpillars or silkworms, eat day and night and increase enormously in size and are kept in clean bamboo trays along with freshly chopped mulberry leaves.
After 25 to 30 days, the caterpillars stop eating and move to a tiny chamber of bamboo in the tray to spin cocoons and small racks or twigs may be provided in the trays to which cocoons get attached.
The caterpillar or silk worm spins the cocoon inside which develops the silk moth.
Processing silk :
A pile of cocoons is used for obtaining silk fibres and the cocoons are kept under the sun or boiled or exposed to steam and the silk fibres separate out.
The process of taking out threads from the cocoon for use as silk is called reeling the silk.
Reeling is done in special machines, which unwind the threads or fibres of silk from the cocoon and the silk fibres are then spun into silk threads, which are woven into silk cloth by weavers.