Textiles and Clothing | Page 8

The warp runs the long way of woven fabric or parallel with the selvage and it must be strong, elastic, and not easily parted by rubbing. To prepare the warp, two threads of raw silk are slightly twisted. Twist is always put into yarn of any kind to increase its strength. These threads are united and twisted together and this makes a strong thread capable of withstanding any reasonable strain in the loom and it will not roughen. For the woof or tram which is carried across the woven cloth on the shuttle, the thread should be as loose and fluffy as possible. Several threads are put together, subjected to only a very slight twist--just enough to hold the threads together so they will lie evenly in the finished fabric.
[Sidenote: Boiling Off]
After the yarn leaves the spinners it is again run off on reels to be taken to the dye house. First the yarn is boiled off in soapy water to remove the remaining gum. Now the silk takes on its luster. Before it was dull like cotton. The silk is now finer and harder and is known as "souple."
[Sidenote: Loading Silk]
The silk fiber has a remarkable property of absorbing certain metallic salts, still retaining much of its luster. This process is known as "loading" or "weighting," and gives increased body and weight to the silk. Silk without weighting is known as "pure dye," of which there is little made, as such goods take too much silk.
[Illustration: REELING SILK]
For the weighting of white or light colored silk goods, tin crystals (stanous chloride) are used and for dark shades and black, iron salts and tannin. By this means the original weight of the fiber may be increased three or four hundred per cent. This result is not attained, however, except through the weakening of the fiber.
[Sidenote: Action of Common Salt]
Common salt has a very curious action on weighted silk. It slowly weakens the fiber. A silk dress may be ruined by being splashed with salt water at the seashore. Most often holes appear after a dress comes back from the cleaners; these he may not be to blame for, as salt is abundant in nearly all the bodily secretions,--tears, perspiration, urine.
[Sidenote: Artificial Silk]
Artificial silk is made by dissolving cellulose obtained from cotton. It is lacking in strength and water spoils all kinds manufactured at present.
[Sidenote: Characteristics of Silk]
Silk, like wool, has the property of absorbing considerable moisture without becoming perceptibly damp. Like wool and all the animal fibers, it is harmed by alkalis. The important physical properties of silk are its beautiful luster, strength, elasticity and the readiness with which it takes dyes. Silk combines well with other fibers, animal and vegetable.
[Sidenote: Value of Raw Fibers]
A comparison of the relative value of textile fibers may be seen from the following approximate prices:
Cotton--$.07 to $.14 per pound; loss in cleaning and bleaching 5 per cent.
Flax--$.12 to $.30 per pound; loss in cleaning and bleaching about 20 per cent.
Wool--$.15 to $.30 per pound; loss in scouring 20 to 60 per cent.
Raw Silk--$7.00 to $10.00 per pound; loss in "boiling off" about 30 per cent which is made up and much more by "loading."

MODERN METHODS
All the complex processes and machinery of the textile industry are but developments of the old-time methods of the home. Brief outlines only will be given here for the processes are most intricate in detail.
SPINNING
The spinning of cotton yarn (thread) is typical of all the fibers. The stages may be divided into--
1. Opening and picking. 2. Carding. 3. Combing. 4. Drawing. 5. Spinning.
[Sidenote: Picking and Carding]
The picking and carding have for their object the removal of all foreign substances with as little damage to the fiber as possible. The foreign substances in cotton are sand, dirt, pieces of leaves, seed, husk, etc., which have become mixed with the fiber during the process of growing, ginning and transportation.
[Sidenote: Cleaning]
The cotton bales are opened and thrown into the automatic feeder which carries up a layer of cotton on a spiked apron from which it is removed by a rapidly revolving "doffer" underneath which is a screen which catches some of the dirt. It is next fed between rolls in front of a rapidly revolving blunt-edged knife which throws out more of the dirt through a screen. There is a suction of air through the screen which helps remove the foreign substances. The cotton passes through several of such machines, being formed into a soft web or "lap" which is wound into a roll.
[Sidenote: Carding]
The carding machine further cleans the fibers and lays them in a general parallel position. From this machine the web is formed into "sliver," a loose rope of cotton fiber about two inches in diameter. This is received in circular cans.
[Illustration: COTTON OPENER AND PICKER
The cotton from the bale