How is silk made?
The production of cultivated silk is called sericulture. The steps involved in the production of silk are as follows:
• Laying of eggs: The adult female moth lays tiny, pinhead-sized eggs of about 500 eggs. The gg has a soft spot on one end from where the larvae hatch.
• Hatching: The mulberry leaves are fed to the larvae in abundance. The larvae eat for about a month and moulds 4 times. After the fourth moulting, the eating continues for about 10 more days.
This tends to increase the weight of the larvae and the larvae then weight 10,000 times more than their birth weight. Also, the length increases by nearly 8cm and diameter by 1cm.
• Extrusion: Then the larvae finally extrude two strands of fibroin with a coating of sericin i.e. a water-soluble gum from the spinnerets that are present on its head. The strands harden when they come in contact with the air.
• After which the caterpillar forms the cocoon by moving his head in the shape of digit 8. The outer cocoon is formed first followed by the inner cocoon and finally, it takes about 2-3 days for the cocoon to be completely formed.
• The cocoons are then put in the hot water to kill them and soften the case. The filament ends are then picked up by the automated machine which brushes these soft cocoons.
Finally, after the cultivation of silkworm and obtaining the filament fiber these fibers are then processed. The processing of silk involves 3 major steps:
• Reeling: The process of combining and passing the ends of filament through a guide before winding them on the circular frame is called reeling.
• Throwing: This step involves the production of thrown yarn which is formed when the strands are twisted to help them hold together. The broken or damaged cocoon produces short or staple fibers that are less expensive and of low quality.
• Degumming: The final step involves removing the gum from yarn or fabric by boiling them in a solution of soap and boiling water.