I went to a silk factory about a week ago and do you know what I learned? They have to kill the silk worms to make the silk! I suppose that might’ve been obvious, but it’s still very sad to know all the worms die. They are just peacefully hanging out in their cocoons and then BAM they’re dead.
Although, I suppose it’s worth noting that once they come out of their cocoons, they only live long enough as moths to lay eggs and die. So their lives are only slightly shortened if that’s any better…
The farmers feed the silk worms mulberry leaves until they get big and fat, then they put them on bundles of sticks where the fat worms will wrap their cocoons. A silk worm’s cocoon is made up of one really really long thread of silk. Sometimes two silk worms will make a cocoon together though. In that case, the farmers use the silk thread only for stuffing comforters because the thread is all tangled. Silly worms.
Our tour guide told us that silk was first discovered when an empress was sitting under a mulberry tree drinking tea and a silk worm cocoon fell into her cup. Her servant reached into the hot cup with a stick to fish out the cocoon and instead continued to pull out a thread for several minutes. And that’s how they discovered silk!
It’s a little different now obviously. No servants sit and fish thread out by hand, but they do still use hot water. Once the silk worm is killed (they have to kill it otherwise it would eat its way out of the cocoon, ruining the thread), the cocoons are put into hot water so the end of the thread will come loose. Once the end is found, eight cocoons are hooked up to each spinner on the machine, which unwinds the thread of the cocoons into a thread. They use eight cocoons because a single thread of silk is 1/8th the width of a human hair. I’m surprised I remember these informational tidbits!
But that’s only for the single worm cocoons. For the double worm cocoons, which are all tangled, they let the cocoon get all mushy in the water, then stretch it across a U-shaped metal structure. They stretch 10 cocoons onto the U, then put that one sheet onto a bigger U-shaped structure to stretch it even more. Only once the bigger U has 10 sheets is the final product ready to be stretched. This sheet is what becomes the padding for silk comforters. So one sheet ready for stretching contains 100 cocoons!
The skilled silk ladies then stretch these 100-cocoon-containing sheets one by one onto a large board. If they stretch too fast or too slow, they will rip the sheet and have to start over. (They let us try to stretch the sheets, and needless to say, we failed miserably.) Obviously a large number of sheets are needed to complete the comforter stuffing, so can you imagine the number of silk worms needed just for one blanket?!
Along with making sheets, pillow cases, clothes, and comforter stuffing, silk is also used to make beautiful art work. The Chinese use colorful silk thread to weave ornate designs onto canvas.