Silk is produced by the silkworm, Bombyx mori. Fed on mulberry leaves, it produces liquid Silk that hardens into filaments to form its cocoon. The larva is then killed, and heat is used to soften the hardened filaments so they can be unwound. Single filaments are combined with a slight twist into one strand, a process known as filature or “silk reeling”.
A Silk filament is a continuous thread of great tensile strength measuring from 500 to 1 500 metres in length, with a diameter of 10-13 microns. In woven Silk, the fibre’s triangular structure acts as a prism that refracts light, giving Silk cloth its highly prized “natural shimmer”. It has good absorbency, low conductivity and dyes easily.
Global Silk production rose from around 100 000 tonnes in 2000 to 150 000 tonnes in 2006, thanks mainly to growth of China’s output. China produces about 70% of the world’s Silk, followed by Brazil, India, Thailand and Viet Nam, with minor production in Turkmenistan and Uzbekistan. The unit price for raw Silk is around twenty times that of raw Cotton.
Source: FAO 2009