Silk Production
Walk into a silk farm and it sounds like rain is gently falling on a wooden roof - its the sound of silkworms munching away on mulberry leaves!
Silkworms eating mulberry leaves
Sericulture, the cultivation of silk, has not changed much since it was first discovered in China. It involves raising the silkworms (which are technically caterpillars) of the Bobyx mori moth. For the first six weeks of their life, silkworms feed exclusively and continuously on mulberry leaves - they eat nearly 50,000 times their weight during this period and need to shed their skin four times!
When the silkworm has grown to about 3 inches long, it stop eating, changes color and starts spinning a cocoon by moving its head in a figure-8 pattern. Using its salivary glands, the silkworm produces a long, continuous filament which solidifies on contact with the air and forms twin filaments of protein material. A second pair of glands secrete a sticky liquid to bond the two filaments. Steadily over the two or three and about 300,000 figure-8's, the silkworm spins about a mile of filament and is completely encased on a cocoon.
At this stage, cocoons are sorted by size, color, shape, and texture, as the quality of silk depends on the combination of these attributes. Cocoons vary from white to yellow to gray.
"Reeling" silk from cocoons
The cocoons are then treated with hot and cold water which softens the binding material and releases the silk in a continuous filament. Very gently the delicate process of "reeling" or combines the three to ten strands of filaments together to make raw silk. It takes about 30,000 silkworms to produce 12 pounds of raw silk!
Raw silk is then washed in soap and boiling water to remove the remaining sericin. When this is washed out in soap and boiling water, the fabric is left soft, lustrous, and up to 30% lighter. Raw silk is twisted into a strand sufficiently strong for weaving or knitting. This process of creating the silk yarn is called “throwing” and prevents the thread from splitting into its constituent fibers. It is then dyed to the desired colour and woven into beautiful silk fabric.