Silk & Its Type:

Silk:

Silk fiber

Silk is a natural protein fiber excreted by the moth larva Bombyx mori, better known as the common silkworm. It's amino acid composition is close to that of the human

skin. Silk is a fine continuous monofilament fiber of high luster and strength and is highly valued as a prestige fiber. Because of its high cost, it finds very 1imited use in textiles. A minor amount of wild tussah silk is produced for specialty items. Attempts have been made to commercialize silk from spiders over the years, but all ventures have met with failure. Domestic and wild silks are essentially uncross linked and relatively simple in amino acid composition compared to the keratin fibers. The properties for silk 1isted here are for silk formed by Bombyx mori moth larvae.

This fiber is the result of caterpillar secretions of certain wild or domestic butterflies which constitutes cocoons in which they lock themselves inside during the metamorphosis. 

Types of Silk:

Raw silk:
Silk fibre as it comes from the cocoon is coated with a protective layer called silk gum, or sericin. The silk gum is dull and stiff. Silk with all of its gum is termed raw silk.

Raw silk

Tussah silk:
Silk made from wild silkworms is called tussah silk. The natural color of tussah silk is usually not white, but shades of pale beige, brown and grey. It is usually coarser than cultivated silk.

Tussah silk

Bombyxmori silk:
It is also known as mulberry silk which is produced by domesticated silkworm raised on diet of mulberry leaves almost exclusively softer, finer and more lustrous than tussah silk. This silk produces shades of white product.

Bombyxmori silk

Reeled silk or Thrown silk:
It is term for silk fibre that is unwound from the silkworm cocoon. It is the most fine silk, the fibres are very long, shiny and of great strength.

Reeled silk

Spun silk:
Silk made from broken cocoon (from which the moths have already emerged) and short fibres, feels more like cotton.

Spun silk

Weighted silk:
When yarns are prepared for weaving, the skeins of yarn are boiled in a soap solution to remove the natural silk gum or sericin. The silk may lose from 20 to 30 percent of its original weight as a result of boiling. As silk has a great affinity for metallic salts such as those of tin and iron, the loss of weight is replaced through the absorption of metals. Thus a heavier fabric can be made at a lower price than that of pure silk, which is known as weighted silk.

Weighted silk

Pure silk:
If the natural gum or sericin is removed from the silk and no further material is added to increase the weight of the fibre, i.e. silk containing no metallic weighting is called pure silk. Pure silk is exclusively soft and possesses fine luster.

Pure silk