Page:EB1911 - Volume 28.djvu/839

Rh one or two more gill-boxes, prior to combing, to ensure straightness of fibre and even distribution of the lubricant.

Prior to the mechanical era wool was combed immediately after scouring; there was no preparatory process. As a matter of fact

the first combing process took the place of the processes just described and was termed “straightening,” the “combing proper” following. Prior to the invention of a really satisfactory mechanical comb, between 1850 and 1860, the combing operation was the limitation of the worsted trade. English wools could be satisfactorily combed by hand, and perhaps the results of combing botany or fine wools by hand were satisfactory so far as quality of result was concerned, but the cost was largely prohibitive. The history of the colonial wool trade is inextricably bound up with the combing industry. How eventually botany wools were combed by machinery and how the wool industry was thereby revolutionized can only be briefly referred to here. About 1779 Dr Edmund Cartwright invented two distinct types of combs, the vertical and the horizontal circular. The former type was developed on the continent by Heilmann and others, and has only within the last five years taken its rightful place as a successful short wool comb in this country. The latter type was worked upon by Donisthorpe, Noble, Lister, the Holdens and others, and largely through the “driving” force of Lister (later Lord Masham) was made a truly practical success about the year 1850. Latter-day combs of this type may be readily grouped under three heads. The Lister or “nip” comb is specially suitable for long wools and mohair and alpaca. The Holden or square-motion comb is specially suited for short and very good quality wools. The last type, the Noble, is the most popular of all and, by a change of large and small circles, may be adapted to the combing of long, medium or short wools. As the great bulk of cross-bred and a considerable proportion of botany wool is combed upon the Noble comb a brief description is here called for. The object of all wool combing is to straighten the long fibres and to comb out from the slivers treated all the fibres under a certain length, leaving the long fibres or “top” to form the sliver which is eventually spun into the worsted yarn. The Noble comb, which so effectually accomplishes this, consists in the main of a large revolving circle A inside which revolve two smaller circles B, B′ as shown in fig. 12, each of which touches the larger comb circle at one point only. At this point the slivers of wool to be carded are firmly dabbed into the pins of both the large and small circles. As the circles continue to revolve they naturally begin to separate, combing the wool fibres between them, the short fibres or “noil” being retained in the teeth of both small and large circles, the long fibres hanging on the inside of the large circle and on the outside of the small circle. A stroker or air

blast at F now directs these long fibres into the vertical rollers, G and G′, shown herein plan, which draw them out, thus separating them from the short fibres. There are at least four pairs of drawing-off rollers in a comb, and the fibres drawn off by each—be it noted continuously—are united to form a sliver which is passed through a revolving funnel into a can. The short fibres, or “noil,” are lifted out of the pins of the small circle by “noil knives.” The continuous slivers, the ends of which remain in the pins of the large circle after the drawing-off rollers have been passed, are now lifted up until these ends are above the pins, at the same time an additional length of sliver being drawn into the comb, so that, as they reach the second small circle, they are ready to be again dabbed into the pins of both circles and the combing operation repeated. Thus the combing on a Noble comb is absolutely continuous. All the movements of this machine—with the exception of the dabbing-brush motion—are circular, so that mechanically it is an almost perfect machine. As illustrating the extent of the combing industry, it is interesting to note that even the making of dabbing-brushes is a separate and by no means unimportant trade.

13.—Section of Wool Drawing Rollers. A, A′ are the back-rollers in a drawing box of which A is positively driven and A′ driven by friction which may be varied at will. Carriers B, B′, B″ simply control the fibres of which the sliver is composed during drafting. The front rollers C, C′—of which C is positively driven and C′ driven by friction—running at a greater speed than A, A′ draft or elongate the slivers as required. The carriers B, B′, B″ should be speeded to run at a suitable rate to assist the drafting operation, more by support than by direct aid. Rollers A, A′ must hold the sliver, hence they are fluted. Rollers C, C′ must pull the sliver somewhat severely, hence roller C′ is covered with leather. The yarn delivered by the front rollers is slightly twisted and wound into a double-headed bobbin of convenient size on the “flyer-system.”

14.—Two-Spindle Drawing-Box.

After combing it is usual to pass the “top” through two gill-boxes termed “finishers.” The last of these boxes, and often the first, delivers the “top” in the form of a ball, thus it is often spoken of as a “balling gill-box.” This stage marks one of the great divisions of the worsted trade, the comber taking the wool up to this point, but now handing it forward in the shape of top to the “worsted spinner,” who draws and spins the slivers into the most desirable worsted yarns.

English tops are usually prepared for spinning by seven or eight operations. Three of these operations are effected in gill-boxes of a somewhat similar type to the preparing-box, only lighter

in build. The remaining four are drawing-boxes, i.e. as shown in figs. 13 and 14, they consist of back and front rollers with small carrying-rollers—not gills—to support the wool in between. Thus an English set of drawing usually consists of a single-can gill-box, a double-can gill-box, a two-spindle gill-box, a four-spindle drawing-box, a four-spindle weigh-box, a six-spindle drawing-box, two six-spindle finishers and three thirty-spindle rovers. About fifteen flyer frames of 160 spindles each will be required to follow this set, although the balance varies partly in accordance with the counts spun to, in this case 1/32's English being the standard.

The object of drawing is to obtain firstly a level sliver from which an even thread may be spun, and secondly to reduce the comparatively thick top down to a relatively thin roving from which the required count of yam may be spun. Of course parallelism of fibres must be retained throughout, so far as possible. To accomplish these objects doubling and drafting is resorted to. Thus the ends put up at the back of the above boxes will be 6, 6, 4, 4, 3, 3, 2 respectively, while the drafts may be 5, 6, 8, 8, 6, 9, 9 approximately.