The Production of Silk
You might recall being in pre-school and having a box of silkworms to take care of. You remember, those little white grubby things that were all nice, fuzzy and gentle, and smelled funny? If you put your ear close to them, you could hear them quietly munch away at those green mulberry leaves. However, little did you realize at the time, the silk produced from silk worms such as those were responsible for the livelihood of over one million workers in China, the well-being of over 700,000 families in India, and contributed to the manufacturing economies of over 60 countries worldwide. From its beginnings of ceremonial use in Ancient China to its explosion of popularity during the Silk Trade, silk, the soft, shiny, breathable material, has remained one of the most coveted luxury items worldwide.
However, although we wear silk regularly, what exactly is it, and how is it manufactured?
Silk as a common material is quite ingenious. It is a natural byproduct of many insects, but for human use, it is most-commonly harvested by means of the silk moth. As nature has devised, when the caterpillar of the silk moth (commonly known as the silkworm) reaches maturity, it will enter the pupal stage of metamorphosis. During this, the silkworm will spin a protective covering of white material around itself, enter hibernation, and transforms into a fully-mature, winged moth. To create this cocoon, the silkworm secretes fibroin, a liquid protein, from its two salivary glands, and pushes these two streams outside of its spinneret, or mouth. Upon reaching air, the fibroin hardens. Then, the caterpillar secrets serecin, a bonding agent, to strengthen the two streams of fibroin together into a soft, resilient material. A single caterpillar will produce this material while twisting in a figure-eight pattern approximately 300,000 times, resulting in around 1 kilometer of filament. This filament, once again, will protect the caterpillar as it undergoes its final transformation into a fully-mature moth.
However, for humans to utilize this material to create silk, there is a problem. If this insect emerges from its cocoon a fully-developed moth, the precious kilometer of thread would be ripped and unusable for turning into thread for clothing or textiles. Therefore, human manufacturers of silk breed silkworm moths by the thousands, only to boil them in water or blast them with hot air upon entering their cocoons. Once the moths are dead, the strands can be unwound due to heat, woven together, and turned into thread, otherwise known as silk. Even with one kilometer of silk manufactured per silkworm, approximately 2500 caterpillars must be killed to create one pound of the material. Likewise, approximately 10 billion silkworms are harvested each year just for their silk.
Given the great cost of insect life it takes to manufacture this lustrous and fascinating material, we have no excuse but to take care of our silk items properly. Dry cleaning is an excellent way of doing so, and making sure that your silk products last as long as possible.