Question

Why r cocoons boiled in hot water or treated in ovens?

Answer 1

The breading and manufacture of silkworms for production of silk is called as Sericulture.

Stiffling :

 The process of killing the pupae inside the cocoon is called as Stiffling.

For obtaining the commercial silk, the cocoons are treated with hot water or placed in a hot oven  to soften the cocoons upper layer and to kill the pupa inside.If not killed, pupa will turn to moth which will cut open the cocoon and come out  and we will not be getting the continuous silk threads.

Answer 2

to obtain silk fibre from the cocoons as silk only separates from cocoons in very much hot water or in very much heated temperature