SERICULTURE

Sericulture, orSilk farming, is the rearing ofsilkwormsfor the production ofsilk. Although there are several commercial species of silkworms,Bombyx mori is the most widely used and intensively studied silkworm. Silk is known as the queen of textile and Biosteel because of its strength.

Stages of ProductionThe silk moth lays eggs.The eggs hatch, and the larvae feed on mulberry leaves.When the silkworms are about 10,000 times heavier than when they hatched, they are ready to spin a silk cocoon.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.Due to quality restrictions, the amount of usable silk in each cocoon is small. As a result, 5500 silkworms are required to produce 1kg of silk.The silk at the cocoon stage is known as raw silk. One thread consists of up to 48 individual silk filaments.

Life cycle of Silkworm

Method of Silk production

STEP 1 Young silk worms prefer tender young mulberry leaves fed 3 times a day. On average, 36,000 worms consume 1 ton of mulberry leaf over their lifetime. The silk worms increase in length by more than 40 times (approx. 3 inches) within 20 days of their feeding time and shed their skin 4 times in the process. When the silk worms are ready to spin, they are put into a round basket covered by cloth to keep them free from flies.

STEP 2 After the worms are completely transformed into cocoons, the cocoons are put into hot, almost boiling water. The filaments from several cocoons are then reeled together on a wooden spindle into a uniform strand of raw silk. Each Thai silk cocoon can give about 700 yards long of filament.

STEP 3 Thai silk yarns must be washed and degummed by immersing the skeins in large tubs of hot water then dried under the sun. Dyes are prepared in a dye bath. Once the dye is ready, the clean yarns are then immerse in the dye bath and boil with constant rotation of the yarn. The dyed yarns are hung in the shade to dry before they can be spun.

STEP 4 Thai silk yarns are then spun by hands on wooden or plastic tubes to be prepared for warp or weft. To make heavier silk, two or more weft yarns are reeled together by hands to make a thicker silk yarn. The more number of weft yarn reeled together, the heavier the silk fabric becomes. The term "ply" i.e. 2-ply, 4-ply, 6-ply is often used to indicate the weight of Thai silk fabric.

STEP 5 After the warp and weft are prepared, the loom is set and the weaving can begin. Most of the Thai silk is hand-woven which gives it a lustrous sheen and slightly uneven texture that distinguishes it from the sleek machine-woven fabric. Weaving silk by hand loom is a rather time consuming and require special skill. A skilled weaver can weave a few inches a day on a very complicated weave. A fast weaver can weave up to a maximum of 9-10 yards a day for a simple plain weave.

Sericulture(silkworm) was the origin of many major changes in the world, for example:

the Silk Routes, the first acts of globalization;the study of the diseases of the silkworm by Pasteur, the advent of microbiology;transgenesis of the silkworm, animal biotechnology.

Sericulture, although practiced of more than 5,000 years, has certainly a role to play for the 5,000 years to come.