The average yield of raw silk in Thailand is 26kg per hectare. Korea produces 80kg per hectare and China 125kg per hectare. In 1995 a garment supplier to one of the major chain stores in the UK, moved into a state-sponsored silk production factory in Hanzhou, China. Under one roof the firm cultivates mulberry trees, harvest silkworm cocoons, spin the yarn and manufacture silk blouses. It has the capacity to make 1 million blouses every year.
Silk production is big business.
Silk - A Hardened Glandular Fluid Silkworms possess a pair of specially modified salivary glands called silk glands or sericteries which are used for the production of silk cocoons. These glands secrete a clear, viscous, proteinous fluid that is forced through openings called spinnerets on the mouthpart of the larva. As the fluid comes into contact with the air it hardens. The diameter of the spinneret determines the thickness of the silk thread. The first stage of silk production is the hatching of the silkworm egg in a controlled environment such as an aluminium box, which are then examined to ensure they are free of disease.