Textiles and Clothing | Page 6

of sheep after being sheared is divided into different parts or
sorted, according to the quality of the wool, the best wool coming from
the sides of the animal.
[Illustration: WOOL FIBERS
a--Medium Wool; b--Camel's Hair; c--Diseased Fiber; d--Merino Wool;
e--Mohair.]
[Sidenote: Scouring Wool]
As it comes from the sheep, the wool contains many substances besides
the wool fiber which must be removed before dyeing or spinning. This
cleansing is called scouring. Before scouring, the wool is usually
dusted by machines to remove all loose dirt. The scouring must be done
by the mildest means possible in order to preserve the natural fluffiness
and brilliancy of the fiber. The chief impurity is the wool grease or
"yolk" which is secreted by the skin glands to lubricate the fiber and

prevent it from matting.
[Illustration: ONE METHOD OF WOOL SORTING
1--The Best Grade; 2--Lowest Grade; 3--Fair; 4--Medium Grade.]
[Sidenote: Scouring Agents]
In the scouring of wool, soap is the principal agent. Soft soap made
from caustic potash is generally used as it is less harmful than ordinary
hard soda soap. Potassium carbonate--"pearl ash"--is often used in
connection with the soap. If the water for scouring is hard, it is softened
with pearl ash. The temperature of wash water is never allowed to go
above 120° F. The scoured wool weighs from a little over a half to
one-third or less of the weight of the fleece.
[Sidenote: Hydroscopic Moisture]
Wool has the remarkable property of absorbing up to 30 per cent or
more of its weight of water and yet not feel perceptibly damp to the
touch. This is called "hydroscopic moisture." To this property wool
owes its superiority as a textile for underclothing.
[Illustration: WOOL SORTING]
The thoroughly cleansed fiber is made up chiefly of the chemical
substance keratin, being similar in composition to horn and feathers. In
burning it gives off a characteristic disagreeable odor. It is a substance
very weakly acid in its nature, for which reason it combines readily
with many dyes. Wool resists the action of acids very well, but is much
harmed by the alkalis, being dissolved completely by a warm solution
of caustic soda. High temperature harms wool.
FLAX
Next to wool and cotton, flax is used most largely in our textile
manufactures. The linen fiber consists of the bast cells of certain
species of flax grown in Europe, Africa, and the United States. All bast

fibers are obtained near the outer surface of the plant stems. The pith
and woody tissues are of no value. The flax plant is an annual and to
obtain the best fibers it must be gathered before it is fully ripe. To
obtain seed from which the best quality of linseed oil can be made it is
usually necessary to sacrifice the quality of the fibers to some extent.
[Illustration: FLAX]
[Sidenote: Treatment of Flax]
Unlike cotton, flax is contaminated by impurities from which it must be
freed before it can be woven into cloth. The first process to which the
freshly pulled flax is submitted is that of "rippling" or the removal of
the seed capsules. Retting, next in order, is the most important
operation. This is done to remove the substances which bind the bast
fibers to each other and to remove the fiber from the central woody
portion of the stem. This consists of steeping the stalks in water.
[Illustration: A FIELD OF FLAX IN MINNESOTA
The Flax Must Be Pulled Up by the Roots to Give Fibres with Tapered
Ends.
(Photograph of C. R. Dodge).]
[Sidenote: Retting]
(1) Cold water retting, either running or stagnant water. (2) Dew retting.
(3) Warm water retting.
[Illustration: RETTING TANK A--Inlet; B--Undisturbed Water;
C--Bundles of Flax.]
Cold water retting in running water is practiced in Belgium. Retting in
stagnant water is the method usually employed in Ireland and Russia.
The retting in stagnant water is more rapidly done, but there is danger
of over-retting on account of the organic matter retained in the water
which favors fermentation. In this case the fiber is weakened.

[Illustration: RETTING FLAX IN THE RIVER LYS, BELGIUM
From the Government Bulletin, "Flax for Seed and Fiber."]
In dew retting, the flax is spread on the field and exposed to the action
of the weather for several weeks without any previous steeping. This
method of retting is practiced in Germany and Russia. Warm water
retting and chemical retting have met with limited success.
When the retting is complete, the flax is set up in sheaves to dry. The
next operations consist of "breaking," "scutching," and "hackling" and
are now done by machinery.
[Illustration: FIBERS OF FLAX]
Breaking removes the woody center from the retted and dried flax by
being passed through a series of fluted rollers. The particles of woody
matter adhering to the fibers are detached