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Wool Sorting






Fleece wool as it comes to the mill is rolled up in bundles and must
be sorted. This process consists in sorting and classifying the fibers
of the fleece. Not only do the various species of sheep furnish widely
different qualities of wool, but different qualities are obtained from
the same animal, according to the part of the body from which the wool
is taken. This variation in some instances is very marked, and
sometimes is greater than that which separates the wools of the
different breeds of sheep. Hence the sorting and classing of wool
become necessary for the production of good, sound yarn of even
quality.

An attempt to utilize the fleece as a whole would result in the
spinning of uneven, faulty, and unsatisfactory yarns. As many as
twelve or fourteen sorts may be obtained from one fleece (by very fine
sorting), but generally not more than five or seven are made. The
following table shows the relative qualities of wools from the various
parts of a Merino sheep:

1 and 2. Head (top and sides): The wools grown on these parts are
remarkable for length of staple, softness, and uniformity of
character. They are usually the choicest wools in the fleece.

3. Upper part of the back: This also is a wool of good, sound
quality, resembling in staples Nos. 1 and 2, but not as soft or as
fine of fiber.

4. Loin and back: The staple here is comparatively short, not as
fine, but generally of unvarying character, sometimes rather tender.



5. Upper parts of legs: This wool is medium in length but coarse of
fiber, and has a tendency to hang in loose, open locks. It is
generally sound, but likely to contain vegetable matter.

6. Upper portion of the neck: The staple clipped from this part of
the neck is of an inferior quality, frequently faulty and irregular in
growth, and contains twigs, thorns, etc.

7. Central part of the neck: This wool is similar to No. 6 but
rather tender in staple.

8. Belly: This wool is from under the sheep, between the fore and
hind legs. It is short and dirty, poor in quality, and generally
tender.

9. Root of tail: In this wool the fibers are coarse, short, and
glossy.

10. Lower parts of the legs: This wool is generally dirty and
greasy, the staple having no wave and lacking fineness. It is
generally burry and contains much vegetable matter.

11. Front of Head; 12. Throat; 13. Chest: The wools from these
parts are sometimes classed together, all having the same
characteristics. The fiber is stiff, straight, coarse, and covered
with fodder.

14. Shins: This is another short, thick, straight wool of glossy
fiber, commonly known as shanks.

=Classing.= Classing is a grading of the fleeces, and is usually, but
not always, a process preliminary to sorting. It is an important part
of sorting, and when well done greatly facilitates the making of good,
uniform matchings.

=Grades of Wool.= In the grading of wool no set standard of quality
exists. The same classification may be applied in different years, or
in different localities, to qualities of wool showing much variation,
the best grade obtainable usually setting the standard for the lower
grades. The highest quality of wool in the United States is found on
full-blooded Merino sheep.

=Merino Wool.= The Merino sheep was bred for wool and not mutton. The
fleece of this breed is fine, strong, elastic, and of good color; it
also possesses a high felting power. Though naturally short, it is now
grown to good length and the fleece is dense. The Merino sheep is a
native of Spain, and Spain was for a long period the chief country of
its production. It was also in past centuries extensively bred in
England and English wool owes much to the Merino for the improvement
it has effected in the fleeces of other breeds of English sheep. It
was also introduced into Saxony and was highly bred there, and Saxony
soon came to surpass Spanish wool in fineness, softness, and felting
properties. The Merino was introduced into the United States at the
beginning of the nineteenth century. By 1810, 5,000 Merino sheep had
been imported and these 5,000 sheep formed the basis of most of the
fine wool-producing flocks of our country to-day.

The terms half blood, three-eighths blood, and quarter blood refer to
the full-blooded Merino standard. As the scale descends the wool
becomes coarser, the wool of a quarter blood usually being a
comparatively coarse fiber. The general classifications of fine,
medium, coarse, and low, refer to the relative fineness of Merino
combing wools. These distinctions naturally overlap according to the
opinion of the parties in transactions. Picklock XXX and XX represent
the highest grades of clothing wool, the grade next lower being X, and
then Nos. 1 and 2. These again are used in connection with the
locality from which the wool is grown, as Ohio XX, Michigan X, New
York No. 1, etc.

=Difference Between Lamb's and Sheep's Wool.= One of the first points
to be understood in wool sorting is the difference between the wool of
lambs and one-year-old sheep, and that of sheep two or more years old.
Lamb's wool is naturally pointed at the end, because it has never been
clipped. It is termed hog or hoggett wool, and is more valuable when
longer, of about fourteen months' growth. It is finer in quality and
possesses more waviness, which is a help in the process of spinning.

The wool of sheep two or more years old is known as wether. The ends
of the fiber from such sheep are thick and blunted, on account of
having been previously cut. It is necessary to be able to tell at once
a hog fleece from a wether, and this can be done in two ways: by
examining the ends of the fiber to see if they are pointed; or by
pulling a staple out of the fleece. If it is wether, the staple will
come out clean, without interfering to any extent with those around
it; but if hog, some of the fibers will adhere to the one that is
being pulled. Hog wool is generally more full of dirt, moss, straw,
and other vegetable matter.

=Dead Wool= is wool obtained from the pelts of sheep that have died.

=Pulled Wool.= Pulled wool is wool from the pelts[10] as they come
from the slaughter-houses of large packing plants. These pelts are
thrown into vats of water and left to soak for twenty-four hours to
loosen the dirt which has become matted into the wool. From these
vats the pelts are taken to scrubbing machines from which the wool
issues perfectly clean and white. The pelts are next freed from any
particles of flesh or fat which may have adhered to them, and are then
taken to the "painting" room. Here they are laid flesh side up and
carefully painted with a preparation for loosening the roots of the
wool. This preparation is allowed to remain on the pelts for
twenty-four hours, when it is cleaned off and the pelts taken to the
"pulling" room. Each wool puller stands before a small wooden
framework over which the pelt is thrown, and the wool, being all
thoroughly loosened by the "paint" preparation, is easily and quickly
pulled out by the handful. As it is pulled it is thrown into barrels
conveniently arranged according to grade and length.

When a barrel is filled, it is transferred to a large room across
which are several rows of wire netting, raised about three feet from
the floor. Each sheet of netting is about six feet wide. Here the wool
is piled on the netting to a depth of several inches and hot air is
forced underneath it by means of a blower. Meanwhile it is worked over
by men with rakes, and soon dries. When thoroughly dry, it is raked up
and taken to the storeroom, where it is dumped into bins. Here it
usually remains open for inspection and sampling till it is sold, when
it is bagged. The bags of wool ultimately find their way to the woolen
mill or sampling house. Sometimes the fleece will retain its fleece
form, but usually it breaks up. The wool contains lime and has to be
specially treated by a scouring process to prevent lime from
absorbing the cleansing substances used for scouring the wool.

=Delaine Wool= is a variety of fine, long combing wool.

=Cotty Wool=, or cotts, is wool from sheep that have been exposed to
severe weather and lack of nourishment, and for these reasons have
failed to throw off the yolk necessary to feed the wool. As a result
it becomes matted or felted together, and is hard and brittle and
almost worthless.

=Wool Sorter.= The sorter begins by placing the fleece upon his board
or table, always arranging it so that he faces the north, as this
gives the most constant light and no glare of the sun. The fleece thus
spread out shows a definite dividing line through the center. The
sorter parts the two halves and proceeds to analyze their different
qualities. The number of sorts is determined by the requirements of
the manufacturer who, in purchasing his wool, buys those grades that
will produce the greatest bulk of the qualities for present use, and
that leave in stock the smallest number of sorts and least weight for
which he has no immediate use. The sorter then removes all extraneous
matter adhering to the fleece, such as straw, twigs, and seeds, and
cuts off the hard lumps of earth, tar, or paint, which, if not removed
at this time, will dissolve in the scouring process and stain the
wool. With these preliminaries finished, he proceeds to cast out the
locks, according to quality, into baskets or skeps provided for that
purpose. After skirting or taking off the outside edges of the fleece,
usually known as brokes, and the legs and tail, known as breech, he
separates the other portions from the better qualities.


DEGREASING PLANT]

Picklock, prime, choice, super, head, downrights, seconds, breech,
etc., are some of the terms used. Picklock comprises the choicest
qualities; prime is similar to picklock, but slightly inferior; choice
is true staple, but not as fine in fiber; super is similar to choice,
but as a rule not as valuable; head includes the inferior sorts from
this part of the sheep; downrights come from the lower parts of the
sides; seconds consist of the best wool clipped from the throat and
breast; breech, the short, coarse fibers obtained from the skirting
and edgings of the fleece.

In the worsted trade different names are used. The terms generally
adopted are: blue, from the neck; fine, from the shoulders; neat, from
the middle of the sides and back; brown-drawings, from the haunches;
breech, from the tail and hind legs; cowtail, when the breech is very
strong; brokes, from the lower part of the front legs and belly, which
are classed as super, middle, and common.

Fine, short wools are sorted according to the number of counts of yarn
they are expected to spin, as 48's, 60's, 70's, and so on. Thus we see
there are different methods of indicating qualities in different
districts, and also of indicating differences of qualities between the
woolen and worsted branches of the trade.

It may be noted that the quality of the wool varies in the same way as
the quality of the flesh. The shoulder is finest in grain and most
delicate, so the wool is finer in fiber. There is more wear and tear
for the sheep at its haunches than at its shoulders, hence the wool is
longer and stronger; about the neck the wool is short, to prevent the
sheep from being weighted down while eating, etc.; the wool on the
back becomes rough and thin, being most exposed to the rain. From the
foregoing it will be readily seen that there is necessity for careful
sorting, in order to insure obtaining an even running yarn, and
subsequently a uniform quality of fabrics.

=Wool Washing.= Fleece wool as it comes into the market is either in
the "grease," that is, unwashed and with all the dirt which gathers on
the surface of the greasy wool; or it is received as washed wool, the
washing being done as a preliminary step to the sheep shearing. Wool,
unlike cotton, cannot be worked into yarn without being thoroughly
cleansed of its impurities. These impurities consist of greasy and
sweaty secretions, of the nature of a lubricant to the fiber. Combined
with dirt, sand, etc., which adhere to the wool, these secretions form
an encrusting compound, known as yolk, which acts as a natural
preservative to the wool, keeping it soft and supple. This compound,
with other extraneous matter, must be removed before the wool is in a
workable condition. The amount of yolk varies, the greatest amount
being found in fine, short wools from the warm climates. In
long-staple wool the amount of yolk is comparatively small.



Various methods of removing these impurities have been tried; one is
the use of absorbent substances, such as fossil meal, alumina, etc.,
to withdraw the greasy matter, so that the remaining impurities can be
easily removed by washing. In other methods, naphtha or similar
solvent liquids are used to dissolve the wool fats. This is followed
by washing in tepid water to dissolve the potash salts, leaving the
dirt to fall away when the other substances are no longer present. To
work this method with safety requires a costly and intricate plant
with skilled supervision. The method which is practically in universal
use is washing the wool in alkaline solutions, properties of which
combine with and reduce the impurities to a lathery emulsion which is
easily washed off from the wool.

Great stress is laid upon the necessity of care in the washing
process, as the luster may be destroyed and a brownish-yellow tint
given to the wool, the spinning properties very seriously injured, the
softness destroyed, or the fiber dissolved. Some wools are easy to
wash, requiring little soap and a reasonable temperature; other wools
are cleansed with great difficulty. A note, therefore, should be made
of any particular brand or class of wool requiring special attention,
to serve as a guide in the treatment of future lots. The danger lies
in using unsuitable agents,--hard water, excessive temperatures,
strong reagents, etc.

Caustic alkalies have a most destructive effect on wool as they eat
into it and destroy its vitality. Carbonate alkalies are less severe.
Whatever cleansing substances are used, it is essential that they
should be free from anything that is likely to injure the wool--that
they remove the impurities and still preserve all the qualities in the
wool. If the washing is properly performed the alkaline portion of the
yolk is removed, leaving only the colorless animal oil in the fiber.
If the work is not thoroughly done the wool passes as "unmerchantable
washed." "Tub washed" is the term applied to fleeces which are broken
up and washed more or less by hand. Scoured wool is tub washed with
warm water and soap, and then thoroughly rinsed in cold water until
nothing remains but the clean fiber.



An improved method of washing wool by hand is to have a series of
tanks with pressing rollers attached to each tank: the wool is
agitated by means of forks, and then passed to the pressing rollers
and into each tank in succession. The tanks are usually five in
number, and so arranged that the liquor can be run from the upper to
the lower tank. Upon leaving the pressing rollers the excess of water
is driven off in a hydro extractor[11] and the wool is beaten into a
light, fluffy condition by means of a wooden fan or beater.

=Wool Drying.= The process of drying wool is not intended to be
carried to such an extent that the wool will be in an absolutely dry
state, for in such a condition it would be lusterless, brittle, and
discolored. It is the nature of wool to retain a certain amount of
moisture since it is hygroscopic, and to remove it entirely would
result in partial disintegration of the fibers. Buyers and sellers
have a recognized standard of moisture, 16 per cent. If, on the other
hand, it is left too wet, the fibers will not stand the pulling strain
in the succeeding operations, and if not broken, they are so unduly
stretched that they have lost their elasticity.

The theory which underlies the drying process is that dry air is
capable of absorbing moisture, hence by circulating currents of dry
air in and around wet wool, the absorbing power of the air draws off
the moisture. For continuous drying free circulation is a necessity,
as otherwise the air would soon become saturated and incapable of
taking up more moisture. Warming the air increases its capacity to
absorb moisture; thus a higher temperature is capable of drying the
wool much quicker than the same volume of air would at a low
temperature. A free circulation of air at 75 to 100 degrees F., evenly
distributed, and with ample provision for the escape of the saturated
air, is essential for good work.

=Oiling.= After being scoured wool generally has to be oiled before it
is ready for the processes of spinning, blending, etc. As delivered
from the drying apparatus, the wool is bright and clean, but somewhat
harsh and wiry to the touch, owing to the removal of the yolk which is
its natural lubricant. To render it soft and elastic, and to improve
its spinning qualities, the fiber is sprinkled with lard oil or olive
oil. As the oil is a costly item, it is of consequence that it be
equally distributed and used economically. To attain this end various
forms of oiling apparatus have been invented, which sprinkle the oil
in a fine spray over the wool, which is carried under the sprinkler by
an endless cloth.

=Burring and Carbonizing.= After wool has been washed and scoured it
frequently happens that it cannot be advanced to the succeeding
operations of manufacture because it is mixed with burs, seeds,
leaves, slivers, etc., which are picked up by the sheep in the
pasture. These vegetable impurities injure the spinning qualities of
the stock, for if a bur or other foreign substance becomes fastened in
the strand of yarn while it is being spun, it either causes the thread
to break or renders it bunchy and uneven. For removing burs, etc.,
from the wool two methods are pursued: the one purely mechanical, the
other chemical, and known respectively as burring and carbonizing.

=Bur Picker.= For the mechanical removing of burs a machine called the
bur picker is employed. In this machine the wool is first spread out
into a thin lap or sheet; then light wooden blades, rotating rapidly,
beat upon every part of the sheet and break the burs into pieces. The
pieces fall down into the dust box or upon a grating beneath the
machine, and are ejected together with a good deal of the wool
adhering to them. Often the machine fails to beat out fine pieces and
these are scattered through the stock.

=Process of Carbonizing.= For the complete removal of all foreign
vegetable substances from wool the most effective process is
carbonizing, in which the burs, etc., are burned out by means of acid
and a high degree of heat. The method of procedure is as follows: The
wool to be treated is immersed in a solution of sulphuric or
hydrochloric acid for about twelve hours, the acid bath being placed
in cement cisterns or in large lead-lined tubs and not made strong
enough to injure the fiber of the wool. During the immersion the stock
is frequently stirred. Next, the wool is dried and then placed in an
enclosed chamber and subjected to a high temperature (75 degrees C.).
The result of this process is that all the vegetable matter contained
in the wool is "carbonized" or burned to a crisp, and on being
slightly beaten or shaken readily turns to dust. This dust is removed
from the wool by various simple processes. The carbonizing process was
first introduced in 1875, though it made but slight headway against
the old burring method until after 1880.

=Blending.= Pure wool of but one quality is not often used in the
production of woven fabrics, so, before the raw material is ready for
spinning into yarn, or for other processes by which it is worked into
useful forms, it is blended. Wools are blended for many reasons (among
which cheapness figures prominently), the added materials consisting
usually of shoddy, mungo, or extract fibers. Ordinarily, however,
blending has for its object the securing of a desired quality or
weight of cloth. The question of color, as well as quality, also
determines blending operations, natural colored wools being frequently
intermixed to obtain particular shades for dress goods, tweeds,
knitting yarns, etc. Stock dyed wools are also blended for the
production of mixed colors, as browns, grays, Oxfords, etc. There is
practically no limit to the variety of shades and tints obtainable by
mixing two or more colors of wool together. The various quantities of
wool to be blended are spread out in due proportion in the form of
thin layers, one on top of the other, and then passed through a
machine called the teaser. The teaser consists of a combination of
large and small rollers, thickly studded with small pins, which open
the wool, pull it apart, and thoroughly intermix it. A blast of air
constantly plays upon the wool in the teaser and aids the spikes and
pins in opening out the fibers. The material is subjected to this
operation several times and is finally delivered in a soft, fleecy
condition, ready to be spun into yarn.





Next: Wool Substitutes And Waste Products

Previous: Fibers



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