to positively control the driving and speed of both flyer and bobbin
in all the drawing frames of such sets as that described above.
Such control is usually effected by a pair of cones, from which this
system has taken its name. viz. “cone” drawing. In fig. 16 a usual
type of cone drawing-box is illustrated. The chief advantages of this
system seem to be the possibilities of employing larger bobbins, and
thus obtaining greater production, the consumption of relatively
less power, and more particularly the production of a softer sliver
with less twist, partaking more of the character of a French roving.
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Fig. 17.—Section of Cap Spindle. |
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C, C′ are the front rollers of a cap spinning frame delivering the yarn through the centring board D under the edge of the cap E to the bobbin F, which rests upon the tube and wharl G, which in turn rest upon the lifter-rail I, which effects the necessary traversing. The spindle H is simply, screwed into the framework, and does not revolve, but simply acts as a support for the cap and as a centre of motion for the tube and bobbin. |
Spinning is usually effected upon the cap frame (see fig. 17)—a frame in which the bobbin, resting upon a fixed spindle, is itself driven at say 5000 revolutions per minute to put in the twist, while the friction of the yarn on the cap which covers the bobbin enables the bobbin to wind up upon itself the yarn as delivered by the front rollers. The weakness and the strength of the cap frame is that to make reasonably hard bobbins the bobbins must be driven at a high speed.
The French are noted for a special
system of worsted spinning, which, producing
soft botany yarns of a
marked type, is worthy of
more than passing comment.
The preparation is very
similar to the preparation of
botany yarns for the English system
save that as a rule the order of the
French drawing
and spinning.
operations are carding, gilling, combing,
back-washing and finishing. The characteristic
features of the method lie in
the subsequent drawing and spinning.
The drawing-box as shown in fig. 18 consists
of back rollers, porcupine or revolving
gill, front rollers, rubbers and
winding-up arrangement. Thus there is
no twist inserted, the slivers being treated
softly and openly right away through the
processes. A set of this type usually
consists of two gill-boxes preparing for
combing, comb, back-washing machine
and two finishing gill-boxes, first drawing
frame, second drawing frame, the
stubbing frame, the roving frame and the
self-acting mule. After leaving the last
box as a fine soft pith-like sliver, spinning
is effected upon the worsted mule.
The main differences between the worsted
and the woollen mule are firstly, the
worsted mule is fitted with preliminary
drafting rollers, and secondly, there is
little or no spindle draft. As the mule is
an intermittent worker it is natural to
contrast it with the cap frame, which
runs continuously. What the real advantage
is it is difficult to say, but the mule
spun worsted yarn trade is becoming
yearly of more importance, and it is
pleasing to note that English spinners
are at last doing a fair share of this
business.
Upon whichever system the yarns have been spun it will frequently be necessary to twofold them and sometimes to three- and fourfold them. Again the fashion sometimes times runs upon fancy twists, and then it is necessary to be able to produce the various styles of cloud, loop, curl, knop, &c., yarns. Twofolding is Doubling, twisting, etc. done upon the flyer, cap and ring frames. The main difference between the cap and the ring frame is that in the latter a small bent piece of wire, termed a traveller, revolved round a ring by the pull of the spindle through the yarn, serves as the retarder to enable the bobbin to wind the yarn, delivered by the front rollers on to itself (see fig. 19). Fancy twisters are almost universally on the ring system.
Yarns are placed on the market in eight forms, viz. in hank, on spools, on paper tubes, on bobbins, on cops, in cheeses, in the warp form and dressed upon the loom beam. Thus the manufacturer can order the yarn which he requires in the form best suited Yarns. to his purpose.
Although in some few cases special means must be employed for the weaving of woollens, worsteds and stuff goods, still the main principles are the same for all classes of goods (see Weaving). Attention may here be concentrated on the characteristic principles of woollen Weaving.and worsted manufacture.
The characteristic feature of wool and of wool yarns and cloths is the quality of “felting.” This quality has always been made use of in woollen cloths, but in worsted cloths, until comparatively recently, it has been largely ignored. To-day, processes however, cloths are made, ranging from the truest woollen to the typical worsted, of which it would be impossible to Finishing processes. indicate the type of yarn employed without very careful analysis. As it is obviously impossible to give here every variety of finish employed, the two typical styles for woollen and worsted cloths are dealt with in detail, and further to elucidate the matter the finishing of a Bradford “stuff” or “lustre” piece is also given in outline.
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Fig. 18.—Section of French Drawing-Box. |
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A, A′, delivery rollers which control the slivers during the drafting operation. B is the porcupine (or circular gill) and C are the front drafting rollers. D is the funnel through which the slivers pass to the consolidating rubbers E, E, F is a second funnel and G is the condensed sliver wound up at a uniform rate on the roller H. |
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Fig. 19.—Section of Ring Spindle. |
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A is the spindle suitably shaped to receive the bobbin at B, with a wharl for turning at C, running in the specially designed receptacle D, which may be screwed firmly into the spindle rail. The traveller E is drawn round the ring F by the spindle acting through the yam as shown in the plan. The spindle is a fixture and the ring-rail is traversed to distribute the yam on the bobbin. |
The fabric on leaving the loom is first mended and then scoured. The operation of scouring is effected in a “dolly,” and must thoroughly clear the piece so that it is free to take the desired finish. The piece is now soaped and “milled,” i.e. felted. Milling may be effected either in the stocks or in Woollen cloth finishing. the milling machine. The stocks, the main features of which are huge hammers which are caused to fall or are driven positively into the cloth, exert a bursting action eliminating the thread structure. The milling machine acts more by compression, arrangements being made to compress the cloth in length or breadth at will. After milling scouring follows to clear the cloth thoroughly of the milling agents previous to the finishing proper. The cloth is now taken in a damp state to the tendering machine and, being hooked upon a frame running into a heated chamber, is stretched in width and dried in this condition. Raising follows, this being effected by subjecting the surface of the fabric to the action of “teazles” fixed on a large revolving cylinder, the whole machine being termed a “gig.” After raising the fabric is “cropped” by being passed over a blade near which revolving knives work, on the principle of a lawn-mower, shearing and levelling the piece. Sometimes fabrics are raised wet, especially if a velvet finish is required. Brushing follows to clear the piece of all stray fibres. The fabric is now ready for “crabbing,” which consists in winding it tightly on to a perforated roller through which steam may be blown or upon which the piece may be boiled. The pieces are then rewound and the operation repeated at least once, to obtain even distribution of finish. Being now ready for pressing, the fabric is cuttled, usually with press papers between each cuttle, and placed in the hydraulic
