The silk industry is undeniably a lavish one yet much about it lays oblivious to the world, even among its greatest supporters. The love for silk dates back centuries and the raging demands for it have over the years raised much controversy in the areas of eco-sustainability and animal cruelty.
Among today’s society of pro-active green and animal lovers, silk been driven to take another step in its evolution. Awareness about eco and animal sustainable silk can only began through the appreciation of the basics. This is the first of a three part article on the basics of silk.
What is silk?
Silk is a fine lustrous fiber that is composed mainly of protein fibroin produced by certain insect larvae (silkworms) to form cocoons to make thread and fabric. Different kinds of silkworms will produce different qualities of silk, although the best known kind of silk is mulberry silk.
Mulberry silk derives its name from the mulberry silkworm (Bombyx Mori), which in turn got its name from the plant on which it lives on.
What’s a silkworm?
Usually when people speak of the silkworm, they are referring to the larva or caterpillar of Bombyx Mori moth although there are other kinds. The Bombyx Mori is a domesticated silkmoth bred and raised in captivity with mulberry leaves.
In general silkworms eat a lot – persistently over a period of about 30 days before it stops for a one day and break four times to shed its skin. The silkworm then will take about 5 days to spin its cocoon. The pupae incubation period lasts for approximately 10 – 15 days and after that the silkmoth emerges to find itself a partner and goes on to lay an average of 500 eggs each. The cycle then repeats itself.
What is Sericulture?
Sericulture is an agro-based industry that involves the commercial rearing of silkworms for the production of raw silk (the yarn obtained out of cocoons spun by silkworms). In sericulture, the major activities comprises of:
- Food-plant cultivation to feed the silkworms (the little workers who spin silk cocoons)
- Reeling of the silk cocoons for unwinding the silk filament to feed into the processing and weaving processes.
Cultivated silk needs to be de-gummed of its Sericin content with a mild alkaline wash in order to obtain the smooth hand of the raw protein fibre. The problem here is, washing off the Sericin will result in almost a 20% reduction the harvested weight of the silk- Which is why manufacturers compensate for the lost weight by saturating the washed silk in a bath of tin-phosphate-silicate salts. ‘Weighted’ silk tends to crush and wrinkle more easily.
Continued in Part 2:
- What is Wild Silk?
- What is Peace Silk, Vegetarian Silk, Ahimsa and Non-Violence Silk?
