Sericulture: Raw Silk

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  • Topic: Silk, Bombyx mori, History of silk
  • Pages : 6 (2052 words )
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  • Published : January 14, 2013
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Sericulture, or silk farming, is the rearing of silkworms for the production of raw silk. Although there are several commercial species of silkworms, Bombyx mori is the most widely used and intensively studied. According to Confucian texts, the discovery of silk production byB. mori dates to about 2700 BC, although archaeological records point to silk cultivation as early as the Yangshao period (5000 – 3000 BCE).[1] About the first half of the 1st century AD it had reached ancient Khotan,[2] and by AD 140 the practice had been established in India.[3] Later it was introduced to Europe, the Mediterranean and other Asiatic countries. Sericulture has become one of the most important cottage industries in a number of countries like China, Japan, India, Korea, Brazil, Russia, Italy and France. Today, China and India are the two main producers, together manufacturing more than 60% of the world production each year.

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Production
Silkworm larvae are fed mulberry leaves, and, after the fourth moult, climb a twig placed near them and spin their silken cocoons. This process is achieved by the worm through a dense fluid secreted from its gland structural glands, resulting in the fibre of the cocoon. The silk is a continuous-filament fiber consisting of fibroin protein, secreted from two salivary glands in the head of each larva, and a gum called sericin, which cements the two filaments together. The sericin is removed by placing the cocoons in hot water, which frees the silk filaments and readies them for reeling. The immersion in hot water also kills the silkworm pupae. This is known as the degumming process.[4] Single filaments are combined to form thread. This thread is drawn under tension through several guides and wound onto reels. The threads may be plied together to form yarn. After drying the raw silk is packed according to quality. [edit]Stages of production

The stages of production are as follows:
1. The silk moth lays eggs.
2. The eggs hatch, and the larvae feed on the mulberry leaves. 3. When the silkworms are about 10,000 times heavier than when they hatched, they are now ready to spin a silk cocoon. 4. The silk is produced in two glands in the silkworm's head and then forced out in liquid form through openings called spinnerets. 5. The silk solidifies when it comes in contact with the air. 6. The silkworm spins approximately 1 mile of filament and completely encloses itself in a cocoon in about two or three days but due to quality restrictions, the amount of usable silk in each cocoon is small. As a result, 5500 silkworms are required to produce 1 kg of silk. 7. The silk is obtained from the undamaged cocoons by brushing the cocoon to find the outside end of the filament. 8. The silk filaments are then wound on a reel. One cocoon contains approximately 1,000 yards of silk filament. The silk at this stage is known as raw silk. One thread consists of up to 48 individual silk filaments. *

third stage of silkworm
 
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silkworms on to Modern Rotary montage
 
* silk cocoon in mountages
The country of origin of silk is China, since it’s also where most silkworm harvesting occurs. For thousands of years, the Chinese have developed techniques and processes to produce the silk fibres to be sold around the world and adapted into products that people demand. The tradition of raising silkworms and turning their cocoons into raw silk is known as sericulture, a craft that has been perfected and handed down for many generations. Ensuring a high quality silk turnover is a complicated process high quality silk skilled in maintaining a precisely controlled environment (temperature and humidity) for the silk worm, and in growing the mulberry tree that is used as food.

Silk fibres are a continuous protein fibre created from natural processes and extracted from cocoons, which means that these fibres can retain the properties that are associated...
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