hread 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.
Fl
|