What
is silk fiber?
Silk is a natural protein fiber, some forms of which can be woven
into textiles.
The protein fiber of silk is composed mainly of fibroin
and is produced by certain insect larvae to form cocoons.[1] The best-known
silk is obtained from the cocoons
of the larvae
of the mulberry
silkworm
Bombyx mori
reared in captivity (sericulture). The shimmering appearance of silk
is due to the triangular prism-like
structure of the silk fibre, which allows silk cloth to refract incoming light
at different angles,
thus producing different colors.Silk is produced by several insects, but generally only the silk of moth caterpillars has been used for textile manufacturing. There has been some research into other types of silk, which differ at the molecular level.[2] Silk is mainly produced by the larvae of insects undergoing complete metamorphosis, but some adult insects such as webspinners also produce silk, and some insects such as raspy crickets produce silk throughout their lives.[3] Silk production also occurs in Hymenoptera (bees, wasps, and ants), silverfish, mayflies, thrips, leafhoppers, beetles, lacewings, fleas, flies, and midges.[2] Other types of arthropod produce silk, most notably various arachnids such as spiders
History of silk
The production of silk originates in China in the Neolithic. Silk remained confined to China until the Silk Road opened at some point during the latter half of the first millennium BCE. China maintained its virtual monopoly over silk production for another thousand years. Not confined to clothing, silk was also used for a number of other applications, including writing, and the color of silk worn was an important guide of social class during the Tang Dynasty.Silk cultivation spread to Japan around 300 CE, and, by 522 CE, the Byzantines managed to obtain silkworm eggs and were able to begin silkworm cultivation. The Arabs also began to manufacture silk during this same time. As a result of the spread of sericulture, Chinese silk exports became less important, although they still maintained dominance over the luxury silk market. The Crusades brought silk production to Western Europe, in particular to many Italian states, which saw an economic boom exporting silk to the rest of Europe. Changes in manufacturing techniques also began to take place during the middle Ages, with devices such as the spinning wheel first appearing. During the 16th century France joined Italy in developing a successful silk trade, though the efforts of most other nations to develop a silk industry of their own were unsuccessful.
The Industrial Revolution changed much of Europe’s silk industry. Due to innovations in spinning cotton, cotton became much cheaper to manufacture and therefore caused more expensive silk production to become less mainstream. New weaving technologies, however, increased the efficiency of production. Among these was the Jacquard loom, developed for silk embroidery. An epidemic of several silkworm diseases caused production to fall, especially in France, where the industry never recovered. In the 20th century Japan and China regained their earlier role in silk production, and China is now once again the world’s largest producer of silk. The rise of new fabrics such as nylon reduced the prevalence of silk throughout the world, and silk is now once again a rare luxury good, much less important than in its heyday.
Different Types of Silk
1.
Raw silk
2.
Tussah silk
3.
Bombyxmori silk
4.
Reeled silk or
Thrown silk
5.
Spun silk
6.
Weighted silk
7.
Pure 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.
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.
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.
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.
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.
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.
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.
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.
