Suzhou | Silk Production
The Discovery of Silk
Page: 1 | 2
Text & Images - Copyright © 2009 Kevin Hulsey
Silk may have been used to manufacture textiles in China as early as 6000 BC, making it one of the first fibers used in manufactured clothing. The credit for using silk as a textile fiber, and the invention of the "silk loom" is given to Xi Ling-Shi, the empress of Huang Di (aka Yellow Emperor) who lived from 2697 BC to 2598 BC.
Chinese legend tells of Xi Ling-Shi observing some silkworms eating mulberry leaves. She collected some of the cocoons, and while drinking tea, Xi Ling-Shi accidentally dropped one of the cocoons into her tea cup. She noticed a small strand of thread separating from the cocoon, and she unwound the strand onto her finger, realizing that it could be used as weaving thread.
Suzhou Silk Factory
Silk thread is a natural byproduct of the mulberry silkworm larvae (Bombyx mori), which spins its cocoon using sericteries, or "silk glands," which secrete a viscous organic liquid protein through its two spinnerets, which are mouth openings in the larva. The clear secreted fluid dries and hardens as soon as it is exposed to the outside air, becoming silk. If allowed to fully mature, metamorphosis will transform the grayish-white silkworm caterpillars into a yellow silkworm moth.
Research Institute (left), Moistening the cocoon (right)
The favorite food of the three-inch-long silkworm larvae is the leaf of the white mulberry (Morus alba), which is native to China and eastern Asia. The silkworm larvae will feed for about six weeks, at which point it will stop feeding and start spinning its cocoon.
Suzhou Embroidery Research Institute
Established in 1957, the Suzhou Embroidery Research Institute is located in the "Mountain Villa of Secluded Beauty," a garden in Suzhou.
The first step in the silk production process is to treat the cocoons with boiling water or steam to reduce the "gumming force" that binds the silk filaments together. A single cocoon can produce a filament measuring over 1,000 meters in length.
Silk Reeling Mill with silk skeins at top
Silk thread is produced on a silk reeling mill by pulling the silk filaments from the moistened cocoon (brushing, picking, and unwinding), and then twisting 7 to 8 silk filaments together. The cocoons are soaked in hot water; then the filaments are hand-separated and wound onto mechanical coil bobbins or skeins at the top of the reeling-mill. This process is called reeling, or filature.
Separating silk filaments from the cocoon (left)
After the silk thread is wound onto the skeins it is re-reeled into hanks. The re-reeling is done to dry the thread, increasing its elasticity while maintaining its "elongation rate." There are four different classifications for silk thread: crepe, organzine (warp thread), tram, which are twisted in two directions, or "thrown singles" which are single threads twisted in one direction.
Stretching the silk for use as a filling material
When used as a filling for a comforter or duvet, the silk is stretched into sheets and stacked into a pile. The use of silk comforters is considered a status symbol in the Chinese culture, making them a popular wedding gift. A silk comforter is never washed, as the water can damage the silk fiber. Cleaning is accomplished by placing the comforter in the sun twice a year.
The art of Chinese silk embroidery began with the its use in elaborate ceremonial garments such as the dragon robe worn by the Chinese Emperors.
There is some controversy over the use of silk in the "animal rights" community, as the process requires the killing of the insect larvae. In response to this, there have been attempts to cultivate natural silk without the need to kill the larvae.
Information on Silk Textile Production