Silk

Silk

　　A continuous long fiber formed by the solidification of the silk fluid secreted by mature silkworms when spinning cocoons. Also known as natural silk, it is a type of natural fiber and one of the earliest animal fibers used by humans. Archaeological findings suggest that as early as 4,700 years ago, China was using silk to make threads, weave ribbons, and create simple silk fabrics. During the Shang and Zhou dynasties, silk was woven into various textiles such as gauze, damask, fine silk, sheer silk, crepe, brocade, and embroidered fabrics. There are several types of silkworms, including mulberry silkworms, oak tasar silkworms, castor silkworms, cassava silkworms, willow silkworms, and wild silkworms. The silk filament obtained from a single cocoon is called cocoon silk. It consists of two single fibers bonded together by sericin. During the reeling process, silk filaments from several cocoons are drawn out and bonded by sericin to form a single silk thread, collectively referred to as silk. Silk from which the sericin has been removed is called degummed silk. The most widely used type of silk is mulberry silk, followed by oak tasar silk. Other types of silk are produced in limited quantities and have not formed significant resources. Silk is lightweight and fine, with fabrics that have a lustrous sheen, offer comfortable wear, and feel smooth and full to the touch. It has poor thermal conductivity, is moisture-absorbent and breathable, and is used in weaving various types of silk fabrics and knitted goods, as well as in industries, national defense, medicine, and other fields. China, Japan, India, the former Soviet Union, and North Korea are the major silk-producing countries, accounting for over 90% of the world's total silk production.