Fibre to Fabric - Chapter Wise CBSE Solved Question and Answer Based On NCERT
Long Q&A
Q1: Explain the process involved in obtaining wool.
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Ans:
For obtaining silk, moths are reared and their cocoons are collected to get silk threads. The cocoons are boiled to separate out silk fibres from cocoon. Threads obtain from the cocoon spun into silk threads, which are woven into silk cloth by weavers. The process of taking out threads from the cocoon for use as silk is called reeling the silk.
Sericulture is the rearing, breeding and management of silkworms for the production of raw silk. For obtaining silk, silk worm moths are reared and their cocoons are collected to get silk threads. Silk yarns come from the cocoon of the silkworm. The caterpillar hatches from a very small egg and is an eating machine. Their diet of continually eating mulberry leaves results in a semi-liquid protein called fibroin. When the silkworms start its spinning process in the cocoon, the worm's head is coated with a gummy protein called sericin. The silkworm rotates its body thousands of times extruding one continuous strand of silk the length of 12 football fields. The silk adheres to itself, forming the cocoon.
Female silk moth lays hundreds of eggs at a time; these eggs are stored carefully on strips of cloth or paper and are sold to silkworm farmers. The eggs are kept in hygienic condition and under suitable temperature and humidity, then the eggs are warmed to suitable temperature and the larva is hatched from the eggs. This is done when mulberry trees bear a fresh crop of leaves. The larvae called caterpillar eat day and night and gets bigger and bigger in size, and are kept on clean bamboo trays along with freshly chopped mulberry leaves. After 25 to 30 days caterpillars stop eating and move to a tiny chamber of bamboo in the tray to spin cocoons. The caterpillar or silkworm spins the cocoon inside which silk moth is developed.
Q2: Explain the process of obtaining silk from the silk moth.
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Ans:
The processing of fibres into wool involves the following steps:
Step I: Shearing: - At first hair are removed using shearing machine
Step II: scouring : - Hair is washed in tanks to remove grease, dust and dirt. This process is called scouring.
Step III: After scouring, sorting of hair is done on the basic of different textures
Step IV: The small fluffy fibres, called burrs, are picked out from the hair
Step V: The fibres then dyed in various colours, according to choice
Step VI: The coloured fibres are straightened, combed and rolled into yarn.
