Various distinctions are given between these two yarns; viz., that woolen is made from short wool and worsted from long wool, and that woolen is carded and worsted combed. While both these statements are to a certain extent true, the real distinction lies in the fact that woolen thread has is fibers running in many directions, more or less tangled, while worsted thread has its fibers quite parallel. Since woolen cloths are quite largely felted, this crisscrossing in every direction leaves many loose ends of fibers exposed on the surface to mat together and form a compact material. Worsted, on the other hand, usually shows the threads of the weave, and therefore needs to have the ends of the threads held in place, so not to produce a felted or rough surface. The short fibers seem best suited for woolen and the longer fibers for worsted. The processes used to bring about these two results are quite different.
Fig. 21. Worsted Carding.
Fig. 22. Process in Woolen Manufacture.
A. Wool from sheep's back B. Scoured wool C. Dyed in raw state. D, E. Carded F. Spun.
In making woolen yarn, the fewest processes by which it is possible to get the fiber into the form of yarn are used. There are, perhaps, two sets of carding machines; and as the sliver from the first card is fed into the second it is fed sidewise, thus keeping the fibers more entangled than if it was put in lengthwise. The second carder feeds to the condenser, which delivers a soft, small rope ready to be spun. The principle of the wool-carding machine is like that of the cotton card; series of bristles mounted in rollers and leathern aprons brush the fibers out smooth and somewhat parallel, and form them into a thin sheet. The condenser takes the sheet from the last card and separates it into a number of small rovings or ropes, ready for the mule spinner.
The mule is especially suited to spinning woolen. In it the thread is drawn out to a distance of about two yards, the revolving bobbin twists it, then the thread is wound on the bobbin.
Different sorts of fancy woolen yarns may be made by twisting two yarns together or by winding one yarn irregularly about another, and by other methods. Colors may be varied by dyeing the wool before it is carded, or by mixing different colored wools before they are carded, large, thin sheets of one color being spread on top of another, sprinkled with oil, and then the whole put through the carding machines. Irregular twists or combinations of cotton or silk, twisted with wool, give variety in yarn.
As has been said, in worsted thread all the fibers are laid as nearly parallel as possible; therefore, all the processes in its preparation for spinning have as their object this straightening out of the fibers. Not all worsteds are alike, but are usually divided into three classes, the first and finest class requiring most processes and being most parallel, the next not quite so even, and the third class of carpet yarns being least parallel.
The processes by which the desired results are obtained vary with different wools. Short wools are carded, as for woolen yarns, care being used to place the fibers as much in one direction as possible. The speed of the cards must be regulated to prevent tearing the wool, and when the process is complete the wool is removed from the card in a soft, untwisted rope, similar to the sliver from the cotton card. Another preparatory process, and the one commonly used for long wools, consists in passing through a set of gill boxes, whose function is as follows: "Their task is to comb and straighten out the wool without definitely removing the short fibers, and their working parts are fairly simple. There are two pairs of horizontal rollers, and between them a number of actual combs, their teeth in a vertical position. The trade does not use the word comb in this connection, but it applies strictly. Faller is the technical term, a word which describes the motion rather than the character of these combs, for each in turn moves forward along a pair of screws, with and through the wool, falls as it reaches the second pair of rollers, is carried back on a low level pair of screws, raised by a lever to its former position, and so da capo. Before entering the first pair of rollers the locks of wool are laid parallel and roughly straightened by hand. As the fallers move faster than the front rollers, and the back rollers faster than the fallers, the wool is at the same time dragged straight and combed straight. The boxes are of course graduated: in the first there may be two pins to an inch on the fallers; the last has fourteen to sixteen. Long wool usually goes through half a dozen boxes, is then washed, oiled again, and put through at least two more boxes before it is sent to be combed, in the technical sense of the word. The slivers are joined together and drawn out, finer than before, again and again during the process, so that the last sliver of all is sure to be uniform in structure from end to end." 1
Fig. 23. Process in Worsted Manufacture.
1. Unwashed wool 2. Scoured and picked 3. Carded. 4 - 7. Combed 8-18. Stages of drawing.
It is difficult to understand these different operations without having the machine before one, but the whole principle of the gill boxes is to comb the threads more and more parallel, to draw them out into more even strands.
The combing proper which follows, besides completing this process of straightening, removes the short fibers, or, as is usually stated, separates the long fibers, or "tops," from the short ones, or "noil." The combing machine is a very complicated one, and no effort will be made here to describe it. The fibers are caught in the teeth of a revolving circle of metal, from which they are removed by rollers set too far apart to catch the short fibers which drop out. The comb is heated, since the wool seems to work better when warmed.
1Clapham. The Woolen and Worsted Industries, p. 39.
Before the spinning the wool must go through two or three more gill boxes and then be drawn. Drawing is a simple process by which two or more slivers of wool are put through two sets of rollers, the second revolving faster than the first. These draw out the strand until the resulting sliver is smaller than either original one. This process is repeated again and again, the sliver becoming smaller and smaller, and during the last few processes a slight twist is given to it. Spinning then serves to impart a final twist and the worsted yarn is ready for use.
This process is the one used for the best worsted yarns. Those which are made from shorter wools, carded, are put through two or three gill boxes, combed, then drawn and spun, while the carpet yarns and coarse knitting yarns are merely carded. These distinctions are not always exact, as two kinds may be combined, but in general these are the three processes for the different worsteds.
The spinning of woolens and worsteds does not differ greatly. The mule used commonly for woolen is sometimes used for worsted also, although the use of the flyer frame for worsteds is more general.
Weaving is now a purely automatic process. The loom has only to be threaded with the warp, the smooth bobbins wound with filling, and the machinery set in motion. The whole process is marvelous to watch. This automaton is the result of the perfection of inventions, of many centuries of human skill, and of comparatively few years of invention of mechanical devices. Only the tying of broken threads, the putting in of yarn, and the taking out of the cloth must be done by hand.