Silk also is not realy for self providers in our country. Silk is a natural protein substance which is secreted by certain insects and solidifies on contact with the air. It is similar to cobwebs. Chemically silk looks very similar to wool. But silk thread is much finer and smoother.
Silk is a poor conductor of heat and feels warm in winter and cool in summer. Silk can hold 30 to 40% of its weight in moisture without feeling wet. Silk is strong and elastic, and nearly does not crease.
The silk moth (Bombyx mori) is originally from Assam and Bengal (Northeast India). The current domestic butterfly cannot fly and do not eat in the absence of mouthparts. In her short life (7 days) she lays 300 to 500 yellow eggs, the size of a pinhead.
After 20 days, the eggs release small caterpillars, who the next 25 days of their lifes mainly eat. The silkworm is a very difficult eater. He just wants young leaves of the White Mulberry (Morus alba). In that time they are approximately 10,000 times heavier and become 10 centimeters long.
Then they stop eating and weave in two to four days a cocoon around themselves.
If after 20 days the butterflies crawl from the cocoons the cycle begins again.
After 10 days the development of the chrysalisis is degraded by killing her with steam. At the outbreak they would otherwise damage the cocoon and the wires. Soaking the cocoons in warm water will remove the glue that holds the cocoons together. Then they can be unwinded. A good cocoon will provide a long thread of between 300 and 900 meters, about 10 micrometers thick. About 5,000 of these cocoons are required to make one kilogram silk. Eight to ten of these are joined together to a thin thread, forming a thread ithat is strong enough to be able to spin into a yarn.
There are about 2,000 silkworms needed to produce one kilogram of silk thread and this is enough to make a dress. For the production of 10 kilograms of silk 1,200 kilograms mulberry is needed.
Of silk from the spinnerets of the caterpillar surgical yarn is produced, called silkworm gut.
Silk is also used for bow strings and strings of musical instruments.
Silk wire has a tensile strength of 5,200kg/cm2.
"What said the caterpillar? Don’t be so expensive, silkworm!”(Rob Van Vuure)