Silk is a protein fiber made by silk worms and is the only natural fiber that is a filament fiber. Originally, it was believed that an ancient Chinese princess was the first to discover the process for manufacturing silk fabric from the filament fiber produced by silk worms. Even though this was considered to be a legend, the first country to manufacture silk fabric was China. According to Kadolph, Langford, Hollen, and Saddler (1993), China was the only country producing silk for approximately 3,000 years before spreading to other Asian countries. Japan is currently manufacturing more silk than any other country in the world.
Silk has set the standard in luxury fabrics for several millennia. The origins of silk date back to Ancient China. Legend has it that a Chinese princess was sipping tea in her garden when a cocoon fell into her cup, and the hot tea loosened the long strand of silk. Ancient literature, however, attributes the popularization of silk to the Chinese Empress Si-Ling, to around 2600 B.C. Called the Goddess of the Silkworm; Si-Ling apparently raised silkworms and designed a loom for making silk fabrics.
Silk is a filament spun by the caterpillars of various butter flies. Silk is a natural protein filament. Its filament density is 1.34 g/cm which make it a medium weight fiber. Very light weight silk textile materials may be manufacturing from silk filaments.
Different Types of Silk:
Wild or tussah silk: Wild or Tussah silk is a tan-colored fiber from the cultivated silk worm which feeds on so rub oak. As the cocoons are always pierced the fibers are shorter than reeled silk. It is different both physically and chemically from ordinary silk. It is brown in colure, considerably stiffer and coarser .It is less reactive towards chemical. It is used in the shantung pongee.
Thrown or Greg silk: Thrown silk consists of two or more threads of raw silk reeled tighter and given a slight twist.
Organize silk: Organize silk is produced from best cocoons. It contains two or more stands each composed of number of greges twist together slightly. These threads are then doubled and re-twisted in the opposite direction to the original twist in the strands (Strand mean a number of flexible strings twisted together into a rope. Organize silk is used for warp threads when high tensile strength is required.
Tram silk: Tram silk is usually made from cocoons of lower grade, like organize. It is composed of two or more strands of thrown silk lightly twisted together and then doubled.
Chappell silk: When silk is still in the green is spun the yarn is known as chappell.