#wildsilk

Silk cocoon facts The FAO Sericulture Manual records silk yields which vary with silkworm breed, season, rearing condition and freshness of the cocoon. Usually the weight of one cocoon ranges from 1.5 to 2.2 grams, so you would need between 450 and 700 cocoons to make one kilo. The silkworms have eaten between 18 and 20 kilos of mulberry leaves to make this quantity of cocoons. 77% to 80% of the weight of the cocoon is taken up by the pupa. The pupa is not necessarily a waste product as it is full of protein and can be used for food. Without the pupae, one kilo of whole cocoons becomes 200 to 230 grams of empty cocoons. The process of reeling silk from whole cocoons generates waste and the one kilo of cocoons makes only 160 to 200 grams of raw silk (silk which still has sericin). The sericin is about one third of the weight of the raw silk, and after you degum the silk to remove the sericin, you are left with between 100 and 130 grams of silk. As you can see, one kilo of cocoons does not make much silk fabric. There are four ways to produce thread from a silk cocoon. 1. Reeled silk Most commercial silk is reeled from top grade cocoons. A cocoon is like a miniature, hollow ball of string, where the string is lightly glued together. To reel silk, you need to loosen the glue by placing the cocoons in warm water for a while and then unwind the thread of a several cocoons. Finally you need to twist several of these very fine threads together into a slightly thicker thread, in a process called throwing. 2. Degummed cocoons Lower grade cocoons can be degummed. The sericin is removed by simmering the cocoons in water with soap and soda ash; the cocoons then become soft like cotton wool. You can buy degummed cocoons and spin directly from them. 3. Silk hankies Alternatively, degummed cocoons are stretched over a frame to make silk hankies. Silk hankies have longer fibres than silk tops and they can pbe used for spinning or for knitting. 4. Silk tops The residual silk from the reeling operation is degummed and carde into tops. Mulberry silk tops are made of short fibres which can be spun just like wool.#silk #yearn #khadi #wildsilk (at CHAK Islampur)