Question

Given below is a sequence of steps in the processing of wool. Which are the missing steps? Add them.
Shearing, __________, sorting, __________, __________, _________.
NCERT Solutions for Class 7th Science Chapter 3 Fibre to Fabric Page 32 Exercise Question 5

Answer 1

Explanation:

here you're answer mate

The various types in the processing of wool are:

1. Shearing

2. Scouring

3. Sorting

4. Fiber spinning

5. Dying and rolling

Thus, the missing steps are - Scouring, fiber spinning, dying and rolling into silk yarn.

Answer 2

Answer:

The missing steps in the processing of wool are Shearing, Scouring, sorting, Picking and cleaning of small fibres (burrs), Dyeing, and Rolling.

Explanation:

• Animals such as sheep, goats, yak, and camels bear a thick coat of hair on their body.

• These hairs trap a lot of air and as we know air is a poor conductor of heat, wool is obtained from it.

• Wool obtained from the sheep is the most commonly available one and used for waving shawls or knitting sweaters, and thus sheep are reared.

The long processing of fibres into wool involves the following steps:

• Shearing→Scouring→sorting→Picking and cleaning of burrs→Dyeing→ Rolling.

• Shearing is the first step where the hair or fleece of sheep is removed from the body. This is usually done in the summer which helps them to survive without any protective coat.

• Scouring is the second step where the sheared skin obtained is washed thoroughly in tanks to remove the dust, dirt and grease.

• Sorting is the next step where the washed hairy skin is sent to the factory for the separation of hairs of different textures.

• The next step is the cleaning of burrs where the small fluffy fibres(Burrs) are cleaned and picked out from the hair.

• The next step involves the dyeing of the fibres into various colours.

• Rolling is the final step that involves the straightening, combing and rolling of the fibres into yarn. The longer ones are used in woollen sweaters and the shorter ones are used in woollen clothes.  

Hence the missing steps are Shearing→Scouring→sorting→Picking and cleaning of burrs→Dyeing→ Rolling.