Sericulture - AbsoluteAstronomy.com

Sericulture, or silk farming, is the rearing of silkworms for the production of raw silk

Silk

Silk is a natural protein fiber, some forms of which can be woven into textiles. The best-known type of silk is obtained from the cocoons of the larvae of the mulberry silkworm Bombyx mori reared in captivity...

.
Although there are several commercial species of silkworms, Bombyx mori
Bombyx mori
The silkworm is the larva or caterpillar of the domesticated silkmoth, Bombyx mori . It is an economically important insect, being a primary producer of silk...

is the most widely used and intensively studied. According to Confucian

Confucius

Confucius , literally "Master Kong", was a Chinese thinker and social philosopher of the Spring and Autumn Period....

texts, the discovery of silk production by B. mori dates to about 2700 BC

27th century BC

The 27th century BC is a century which lasted from the year 2700 BC to 2601 BC.-Events:*2900 BC – 2334 BC: Mesopotamian wars of the Early Dynastic period.*2775 BC – 2650 BC: Second Dynasty wars in Egypt....

, although archaeological records point to silk cultivation as early as the Yangshao period (5000 – 10,000 BCE). About the first half of the 1st century AD it had reached ancient Khotan

Khotan

Hotan , or Hetian , also spelled Khotan, is the seat of the Hotan Prefecture in Xinjiang, China. It was previously known in Chinese as 于窴/於窴 and to 19th-century European explorers as Ilchi....

, and by AD 140 the practice had been established in India. 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

China

Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...

and India

India

India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...

are the two main producers, together manufacturing more than 60% of the world production each year.

Production

Silkworm larva

Larva

A larva is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle...

e are fed mulberry leaves, and, after the fourth moult

Ecdysis

Ecdysis is the moulting of the cuticula in many invertebrates. This process of moulting is the defining feature of the clade Ecdysozoa, comprising the arthropods, nematodes, velvet worms, horsehair worms, rotifers, tardigrades and Cephalorhyncha...

, climb a twig placed near them and spin their silken cocoons. The silk is a continuous-filament fiber consisting of fibroin

Fibroin

Fibroin is a type of protein created by Bombyx mori in the production of silk. Silk emitted by the silkworm consists of two main proteins, sericin and fibroin, fibroin being the structural center of the silk, and sericin being the sticky material surrounding it.The fibroin protein consists of...

protein

Protein

Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...

, secreted from two salivary glands in the head of each larva, and a gum called sericin

Sericin

Sericin is a type of protein created by Bombyx mori in the production of silk. Silk emitted by the silkworm consists of two main proteins, sericin and fibroin; fibroin being the structural center of the silk, and sericin being the sticky material surrounding it....

, 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.

Single filaments are combined to form thread

Thread (yarn)

Thread is a kind of yarn used for sewing.-Materials:Thread is made from just about everything. Following table lists common materials, a general description and what they are supposed to be good for. If your machine will sew with the thread, any thread can used for just about any purpose. This...

. This thread is drawn under tension through several guides and wound onto reels. The threads may be plied together to form yarn

Yarn

Yarn is a long continuous length of interlocked fibres, suitable for use in the production of textiles, sewing, crocheting, knitting, weaving, embroidery and ropemaking. Thread is a type of yarn intended for sewing by hand or machine. Modern manufactured sewing threads may be finished with wax or...

. After drying the raw silk is packed according to quality.

Stages of production

The stages of production are as follows:

The silk moth lays eggs.
When the eggs hatch, the caterpillars are fed mulberry leaves.
When the silkworms are about 23 days old, they are 10,000 times heavier than when they hatched.

They are now ready to spin a silk cocoon.
Put silkworms on to Modern Rotary montage

The silk is produced in two glands in the silkworm's head and then forced out in liquid form through openings called spinnerets.
The silk solidifies when it comes in contact with the air.
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.
The silk is obtained from the undamaged cocoons by brushing the cocoon to find the outside end of the filament.
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.

External links

The source of this article is wikipedia, the free encyclopedia. The text of this article is licensed under the GFDL.