Everyone seems to know and love silk, admire its drape, luster and soothing feeling. And like any other fibers, silk comes in a wide variety of qualities. It usually comes from the Bombyx mori silkworm that feed particularly on mulberry leaves.
What is Silk Fiber?
Bombyx mori silk worms feed on mulberry leaves and produce the so-called “cultivated” silk, and the same worms feed on something other than mulberry leaves are generally referred to as “tussah;” however, the color is not white but more of a tan or beige.
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Moreover, there are various species of silk worms that produce fiber that can be used for textile purposes – these are referred as “wild” silk.
How it is Being Processed
In order to metamorphose into a moth, the silk worm’s chrysalis should be made up of silk. It is excreted, along with a glue or gum called sericin, thus becomes strong in the long run. From there, the worm becomes completely protected until it is ready to hatch. The silk worms are “stifled prior to hatching, so they can obtain the long length of the fiber.
During harvest, the cocoons are placed in hot water to soften the glue. Traditionally, a small twig is often used to capture most of the filaments for the purpose of reeling the fiber off. This shall kick-start the process of creating yarn.
On the other hand, it is possible to get a short staple silk without it being reeled. Basically, the fiber comes from cocoons that have been allowed to hatch, along with whatever waste there is from the reeling process. As the moth chews the cocoon’s end in order to emerge, the fiber is then cut into small lengths.
Introducing the Spun Silk Yarns
The yarn can either be smooth or textured and weaker or stronger, but should depend on how the silk yarn has been produced and spun. In most cases, the sericin is removed; however, several yarns may have some of the glue left, thus need to be scoured out so as to bring the soft drape that is associated with cloth.
These are just some of the names of textured silk yarns – namely, bourrette, slub and noil. Tram silk, on the other hand, is unspun and is quite loose in nature. It is commonly used for weft, while organzine silk is a very tightly twisted singles. Lastly, crepe silk is very tightly twisted, but sometimes singles or plied.
What Are the Common Characteristics of Silk Fibers?
Silk becomes strong when dry, but somewhat weak when wet. Also, it has a medium-resiliency while itselasticity is good compared to other fibers. Its absorbency capacity is quite high, and is one of the most flexible fabrics.
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A Bit of Silky History
Since time immemorial, silk has been deemed as a luxurious textile. In Canada, silk arriviedg at the port of Vancouver during the late 19th, but it was only in the early 20th century that it received priority on the trains across the continent – all other trains were side-tracked to let the silk train go first.
Meanwhile in Europe, silk was subjected to sumptuary law that only people of royalty were allowed to wear it for some time. And despite the expanding market that silk has brought to the merchant class, it remained as a status symbol.
During World War II, silk fiber was used for parachutes. However, it was during that time that the fiber became extremely difficult to obtain. There are stories about damaged parachutes being carefully cut up and used for lingerie. Thanks to its strength and flexibility, silk became an important material in makin parachutes.
Eventually, people were able to develop rayon and nylon as silk alternatives. Nowadays, we can see silk being used in all sorts of special garments.