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Fibre to Fabric — Science STD 7 — Question

Gujarat BoardEnglish MediumSTD 7ScienceFibre to Fabric5 Marks
Question
Write and explain the sequence of steps in processing of wool.
✓

Answer

Following are the steps involved in processing of wool:
  1. Shearing, scouring, Sorting, fiber spinning, fiber dying, rolling into Silk yarn.Rearing is raising livestock like goat, cows, sheep etc. for commercial purpose by taking them out in herds for grazing , feeding them on a mixture of pulses, corn, jowar, oil cakes (material left after taking out oil from seeds) and minerals for better growth and yield of produce like meat, milk, wool. Beside this in extreme climatic condition like winter these are also provided shelter and fed on leaves, grain and dry fodder.
  2. Shearing is the process in which fleece of the sheep along with a thin layer of skin is removed from its body. Machines similar to those used by barbers are used to shave off hair. Generally, the hair is removed during the hot weather which enables the sheep to survive without their protective coat of hair. The hair provides woollen fibres. Woollen fibres are then processed to obtain woollen yarn. Shearing does not hurt the sheep as the uppermost layer of the skin is dead.
  3. 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.

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