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Worsted Yarns






=Carding.= After the wool is washed it undergoes a number of
operations before it is finished into worsted or woolen yarn.[12] The
first step in the manufacturing of worsted yarn is to pass the washed
wool through a worsted card which consists of a number of cylinders
covered with fine wire teeth mounted on a frame. The effect of these
cylinders on the wool is to disengage the wool fibers, make them
straight, and form a "sliver" or strand. It is now ready for the
combing machine.

=Combing.= The process of combing consists of subjecting the card
sliver to the operations of the automatic wool comber, which
straightens the fibers and removes all short and tufted pieces of
wool. Combing is a guarantee that every fiber of the wool lies
perfectly straight, and that all fibers follow one after the other in
regular order.

=Comb.= A comb is a complicated machine. The principal feature is a
large metal ring with rows of fine steel pins (pin circles), which is
made to revolve horizontally within the machine. By various devices
the wool is fed into the teeth of the ring in the form of tufts. The
fibers of the tufts by an intricate process are separated into long
and short lengths, and a set of rollers draws each out separately and
winds it into a continuous strand called "tops." On leaving the
comber, the wool is free from short fibers, specks, and foreign
substances, and presents a fine, flowing, and lustrous appearance. The
short combed-out wool is called noils, and is used in making carpet
yarns, ground up into shoddy stock, or utilized in spinning fancy
yarns.

=Worsted Tops.= American textile manufacturers are finding it
advantageous to have their combing done by those who make the work a
specialty rather than to do it themselves. In the manufacture of tops
all varieties of combing wools are used: Australian, Merino, and
Crossbred wools, South American Merino and Crossbred wools, Cape
Merino wools, Merino and Crossbred wools grown in the United States,
the lustrous wools of pure English blood, Mohair from Asiatic Turkey,
and Alpaca from the Andes. Tops are sold to worsted spinneries.[13]
Many mills or worsted spinneries send their wools, either sorted or
unsorted as they may desire, to a combing mill, where the wool is put
into top at a lower price than that at which most spinneries can do
their own combing. By means of the naphtha process a larger amount of
top from a given amount of wool can be secured than by any other
process, and in addition, a top in better condition for drawing and
spinning.


In a strand of combed wool, called top, no single fiber lies across
the strand; all lie in the direction of the length. This order is
preserved until the fibers have been converted into yarn, which is
accomplished by passing through "gill boxes." These gill boxes are
machines with bars of iron having upon their surface two rows of
minute steel pins, by this means kept perfectly straight. The bars on
which they are placed are worked on screws between two sets of
rollers. The wool enters between the first set of rollers, and, as it
passes through, is caught by one of these gills that is raised up for
the purpose, being succeeded by others as the rollers revolve. These
gills are moved forward on screws in the direction of the other set of
rollers, and the pins in the gills always keep the fiber perfectly
straight. The second set of rollers is termed the draught rollers,
since by them the wool, after passing through the front rollers, is
drawn out and reduced in thickness. This is accomplished because the
second rollers revolve at a higher rate of speed than the first
rollers, the speed being regulated according to the length of the
wool, and the thickness of the yarn to be produced. These gills are
used in the production of worsted yarn until the size of the rope of
wool has been so reduced and twisted that there is no chance of any
fiber getting crossed or out of the order of straightness. A worsted
yarn is, consequently, a straight yarn, or a yarn produced from
perfectly straight fibers.


The combing of wool may be dispensed with in some cases, although
such a yarn is not in common use. When combing is dispensed with, the
gills, in connection with the draught of the rollers, make the fibers
straight, and produce a worsted yarn, although such a yarn has a
tendency to be uneven and knotty.

Before the wool can be spun it must be made into roving of a suitable
thickness. This is done by passing it, after being combed, through a
series of operations termed drawing, whose functions are to produce a
gradual reduction in thickness at each stage. Although the number of
machines varies according to the kind of wool to be treated, still the
same principle applies to all.

=Spinning.= The process of spinning is the last in the formation of
yarn or thread, the subsequent operations having for their object the
strengthening of the yarn by combining two or more strands and
afterward arranging them for weaving or for the purpose for which the
yarn is required. It is also the last time that the fibers are
mechanically drawn over each other or drafted, and this is invariably
done from a single roving. The humidity and temperature of the
spinning room must be adjusted to conditions. Each spinner is provided
with a wet and dry thermometer so that the best temperature can be
ascertained. The most suitable heat and humidity can only be obtained
by comparison and observation. A dry and warm atmosphere causes the
wool to become charged with electricity and then the fibers repel each
other.

Worsted yarn is spun by two different methods known respectively as
the Bradford or English system and the French system. The difference
in these systems of spinning worsteds lies principally in the drawing
and spinning processes, a radically different class of machinery being
used for each. The combing process is practically the same in both
cases, but the wool is combed dry for the French system, and by the
English method the stock is thoroughly oiled before being combed. The
result of the English method is the production of a smooth level yarn
in which the fibers lie nearly parallel to each other. The yarn made
according to the French system is somewhat fuzzier and more woolly. On
account of the absence of oil, the shrinkage of French spun worsted is
considerably less than that made by the Bradford system.

=Characteristics of Worsted Yarn.= The unique structure of worsted
yarn makes it invaluable in the production of textile fabrics in which
luster and uniformity of surface are the chief characteristics. The
methods by which worsted is formed render it capable of sustaining
more tension in proportion to its size than the pure woolen yarn. This
feature, combined with its lustrous quality, gives it a pre-eminent
position in the manufacture of fine coatings, dress goods, etc. The
method of arranging the fibers in the formation of a woolen yarn is
such as to produce a strand with a somewhat indefinite and fibrous
surface, which destroys to a large degree the clearness of the pattern
effect in the woven piece. In the construction of worsted yarn the
fibers are arranged in a parallel relationship to each other,
resulting in the production of a smooth, hard yarn having a
well-defined surface; hence weave-ornamentation of a decided or marked
type is possible by its use. There is, in a word, more scope for
pattern effects, since the level and regular structure of the yarn
imparts a distinction to every part of a woven design. From this
peculiarity arises the great variety of effects seen in the worsted
dress fabrics, coatings, trouserings, etc., both in colored patterns
and in fabrics of one shade throughout.

Worsted yarn can be made of pure wool; and as a rule, the wool used in
the English system is of fairly good length and uniform staple, for if
otherwise it is only with difficulty that the yarn can be spun
straight. Shorter wool can be combed and spun under the French
system, and this is the reason why the French system of spinning is
being introduced. On the other hand, in the spinning of woolen yarns
great length of staple is not essential, for the machinery employed
will work the small fibers.

=Uses of Worsted Yarn.= Worsted yarn may be used in any of the
following fabrics:

1. Combed wool yarn for ornamental needlework and knitting, as Berlin,
Zephyr, and Saxony wools.

2. Cloth made from combed wool not classified according to material.

a. Fabrics of all wool--serge, bunting, rep, dress
goods, with weave effects.

b. Wool and Cotton--union goods, serge linings,
lathing.

c. Wool and Silk--rich poplin, pongee, henrietta,
bombazine.

d. Alpaca and Mohair--alpaca, mohair dress goods,
lusters, braids, laces.

=Counts.= Yarn is measured by a system of "counts"--the number of
yards of yarn to the pound. The counts of worsted yarn are based on
the number of hanks in one pound, each hank containing 560 yards. Thus
No. 30 worsted yarn consists of 30 hanks of 560 yards each, or 16,800
yards to the pound.





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