Natural Fibers - Properties

Silk fibers are smooth, translucent, rod-like filaments with occasional swellings along their length. The raw silk fiber actually consists of two filaments called fibroin bound by a soluble silk gum called sericin. Fibroin and sericin are made up of carbon, hydrogen, nitrogen, and oxygen.

Silk has several important qualities: (1) It is lower in density than wool, cotton, or rayon. (2) It is a poor conductor of heat and electricity. (3) It is capable of soaking up to 30% of its weight in moisture. (4) It is extremely strong, with a breaking strength as high as 65,000 psi. (5) It will stretch to as much as 20% of its length without breaking. (6) It is thermally stable; it is able to withstand temperatures as high as 284°F (140°C). (7) It becomes smooth, lustrous, and luxurious when processed. (8) It is remarkably resilient, and shows excellent wrinkle recovery.