Artificial Silk





=Silk Cotton.= On account of the high price of silk various attempts

have been made to find satisfactory substitutes for it. There are

certain seed coverings of plants that contain very fine hair-like

fibers with a luster almost equal to silk, but the staples are short,

and the texture weak. The Kapok plant furnishes most of the commercial

silk cotton on the market. The fibers of Kapok are thin and

transparent. They are extremely light, and the length is less than

half an inch. Silk cotton has a smooth surface and therefore cannot be

spun like true cotton which has corded edges.



=Artificial Silk.= Since seed hairs are composed, like all vegetable

fibers, of cellulose, attempts have been made to prepare an artificial

silk product from waste paper--that is, by treating waste paper or

wood or cotton fibers with various chemicals in order to obtain pure

cellulose. This artificial silk is perhaps the most interesting of

artificial fibers, but its manufacture is dangerous, owing to the ease

with which it catches fire and explodes. Cellulose, chemically

treated, can be transformed into a fluid solution known as collodion.

The collodion is placed in steel cylinders and expelled by pressure

through capillary tubes. After drying, denitration, and washing, it

may be spun and dyed like natural silk. Colored threads may be

produced by the addition of certain dyes.



Artificial silk bears a deceptive resemblance to the natural article,

and has nearly the same luster. It lacks the tensile strength and

elasticity, and is of higher specific gravity than true silk.



=Tests.= A simple way of recognizing artificial silk is by testing the

threads under moisture, as follows: First, unravel a few threads of

the suspected fabric, place them in the mouth and masticate them

vigorously. Artificial silk readily softens under this operation and

breaks up into minute particles, and when pulled between the fingers

shows no thread, but merely a mass of cellulose or pulp. Natural silk,

no matter how thoroughly masticated, will retain its fibrous strength.

The artificial silk offers no resistance to the teeth, which readily

go through it; whereas natural silk resists the action of the teeth.





Appendix Barberry facebooktwittergoogle_plusredditpinterestlinkedinmail

Feedback