[Caitlin]

Silk Thread.

Silk was unraveled and used for the first time in China about 27 centuries ago. Most histories say it was the Empress herself who figured it out. More than half the world’s silk is still produced in China, with India following second. Indai has four kinds of silk producing moths and China sticks with the original mulberry eating moth.

Silk is a protein fiber made from secretions from the jaws of silk-producing caterpillars. The caterpillar extrudes the silk in a long thin thread which wraps around itself in a cocoon. Man must intervene in order to get the silk intact. The caterpillar is thus killed in the cocoon right before it hatches into a moth. The cocoon is immersed in hot water and unrolled into one long filament 300-900 meters is typical. It takes several filaments to make thread for clothing. Broken pieces of silk filament are also used, but the product is not considered as good as the unbroken threads.

(For Slraep. As recently as 2001, child laborers in India did the major part of the work of killing and cleaning the moth out of the cocoon, then unsticking the threads so they can be unwound.. The children must keep their hands in hot water during this process and many have lots of burn scars from the hot water.See Blood on Silk, a Frontline production) http://www.flonnet.com/fl1801/18010660.htm )

Properties of Silk

Silk takes color well and can be dyed into thousands of shades of colors.

[Silk Thread is an elastic, though very strong thread, http://www.redrockthreads.com/silkthread/ ]

silk stretches and degrades with frequent exposure to body oils, soaps, etc., http://www.abeadstore.com/tips_1_stringing.html

Perspiration and sunlight weakens and yellows silk fabrics. Upholstery and drapery fabrics that contain silk should be protected from prolonged exposure to direct sunlight. http://www.fabrics.net/amysilk.asp

Strength: Silk is the strongest natural fiber. The continuous length of the filaments provides greater strength.
Elasticity: The elasticity of silk varies and it can be stretched from 1/7 to 1/5 than its original size. The fiber does not sag much.
Resilience: Silk has a high resilience, and therefore resists wrinkling and also retain its shape. Fabrics made from short-staple spun silk have less resilience.
Absorbency: Silk has good absorbency, contributing to its comfort in a warmer atmosphere. The fiber can absorb about 11 percent of its weight in moisture. This property helps to print and dye the fiber easily.
Heat Conductivity: Silk is a protein fiber and also a non conductor of heat. It can be used for manufacturing winter wear and often blended with other fibers to manufacture high quality home furnishings. http://www.textilefurnishings.com/silk-properties.html

When it is dry the elongation (elastic recovery) varies from 10-25% and when wet it will elongate as much as 33-35%. Silk has a relatively high standard moisture regain of 11%. At saturation the regain is 25-35%.
http://www.vegansociety.com/html/animals/exploitation/silk_worm.php