PREPARATION OF GREY WARPS.
Grey warps are prepared by one or other of two systems, namely, (1) Beam warping, for slasher or tape sizing; and, (2) ball or mill warping, for ball or warp sizing; but by far the greater number are prepared by the first-named system.
1. Beam Warping and Slasher Sizing.
This system comprises the following operations, namely—
1. Winding yarn from cops, ring, or throstle bobbins on to warpers’ bobbins, by means of a “spindle” or “cop” winding machine.
2. Beam warping, whereby yarn is transferred, in the form of a wide sheet, from warpers’ bobbins on to a large flanged beam.
3. Slasher or tape sizing, whereby yarn is withdrawn from several beams, termed “back” or “slashers’” beams, to be sized, and subsequently re-wound by the same machine on to a weaver’s beam by simultaneous operations.
4. Looming, by which the threads of a new warp are placed in a loom ready for weaving.
2. Ball Warping and Sizing.
This system comprises the following operations, namely—
1. Winding yarn from cops or ring bobbins on to warpers’ bobbins.
2. Ball warping, in which a number of threads are withdrawn from warpers’ bobbins and condensed into the form of a rope of untwisted strands. This operation may be accomplished by several types of machines. The one usually employed is the old-fashioned warping mill, which coils warp-ends on to a large revolving reel or swift, from which they are subsequently withdrawn and formed into a large ball. Ball warps are also sometimes formed direct from warpers’ bobbins; also sometimes from sections formed by a sectional warper; and sometimes by means of a linking or chaining machine.
3. Ball-warp sizing.
4. Beaming, or winding a warp in an even sheet of threads on to a weaver’s beam for the loom.
5. Twisting-in or else drawing-in warp-ends in the loom.
If the threads of a new warp are similar in number and counts to those of the finished warp, and are to pass through the shedding harness and reed also in a similar manner, it is more economical to twist the threads of a new warp separately to the corresponding threads of the old warp, and then draw the twisted portion of the warp bodily forward through the healds and reed. If, however, the number of threads and counts are greatly dissimilar, or if a different drafting is required, then recourse must be had to drawing new warp-ends through the harness and reed.
Preparation of Mono-coloured Warps.
Warps of one colour may be prepared from either (1) warp-dyed and sized yarn, or (2) from hank-dyed and sized yarn.
1. (a) Warp-dyeing and Sizing.
The series of operations in this system are identical with those involved in the preparation of grey warps by means of ball warping, but with the additional process of dyeing immediately following the operation of warping, and are as follows:—
1. Winding yarn on to warpers’ bobbins.
2. Mill or other system of ball warping.
3. Warp-dyeing and sizing.
4. Winding yarn on to a weaver’s beam.
5. Twisting-in or drawing-in.
1. (b) Warp-dyeing and Sizing.
A system by which warps of one colour may be prepared by means of sectional warping, from ball-dyed and sized yarn, has been recently introduced. It comprises the following operations, namely—
1. Winding yarn from cops or ring bobbins on to warpers’ bobbins.
2. Mill or other system of ball warping.
3. Warp-dyeing and sizing.
4. Winding yarn from ball warps on to warpers’ bobbins by means of a warp-winding machine.
5. Sectional warping and beaming.
6. Drawing-in or twisting-in.
2. Hank-dyeing and Sizing.
This system involves the following operations, namely—
1. Reeling yarn from cops or ring bobbins into single or multiple hanks. (A standard hank contains 840 yards.)
2. Hank-dyeing and sizing.
3. Winding yarn from hanks on to warpers’ bobbins by means of a drum-winding machine.
4. Beam warping.
5. Beaming, or winding yarn from back beams on to a weaver’s beam.
6. Drawing-in or twisting-in.
Sectional warping may be substituted in lieu of beam warping.
Preparation of Multi-coloured Warps.
Striped warps are usually prepared by one or other of two systems, namely, (1) Yorkshire dressing, from warp-dyed and sized yarn; and (2) sectional warping, from hank-dyed and sized yarn. Warp-dyeing yields a more uniform tone of colour than hank-dyeing, for which reason some manufacturers prefer to adopt the former system, although the latter system is less costly.
1. Yorkshire Dressing.
This system comprises the following operations, namely—
1. Winding yarn on to warpers’ bobbins.
2. Mill or other system of ball warping.
3. Warp-dyeing and sizing.
4. Yorkshire dressing, by which the required number of threads of each colour are split off reserve ball warps. The warp-ends thus split off are subsequently passed, in groups of two to four, through the dents of a reed in proper order, according to the required warp pattern, and wound on to a weaver’s beam.
5. Drawing-in or twisting-in.
2. Sectional Warping.
This system comprises the following operations, namely—
1. Reeling yarn into hanks.
2. Hank-dyeing and sizing.
3. Winding on to warpers’ bobbins by a drum-winding machine.
4. Sectional warping, by which a warp is wound in sections upon wooden or compressed paper blocks, with warp-ends in the same relative position that they are required to occupy in cloth. Each section forms a complete unit of the full warp, and when the required number of units are prepared, they are placed together side by side, and compressed upon a mandril; then the yarn is unwound from all sections simultaneously, and wound on to a weaver’s beam.
5. Twisting-in or drawing-in.
Preparation of Weft Yarn.
If weft yarn is to be woven in a grey state, it is rarely that it requires to undergo any operation after it leaves the spinner. Grey cops and ring bobbins of weft are usually placed in a shuttle and woven direct; but if they are too large for a shuttle, their yarn is transferred on to wooden or paper bobbins by means of pirn winding.
Cops intended for use as weft are frequently dyed and bleached in that form, and woven without any operation of winding. If, however, weft yarn is dyed or bleached in hanks, it requires to be subsequently wound on to pirn bobbins or paper tubes to fit on a shuttle tongue. Weft is also sometimes woven in a damp condition, with a view to inserting a greater number of picks per inch in cloth than is possible with dry weft.
Winding Machines for Warp Yarn.
[Fig. 1] is a diagram showing parts of a “spindle” or “cop” winding machine, which is chiefly employed to wind grey yarn from cops, G, or ring bobbins on to warpers’ bobbins, E. It is also sometimes incidentally employed to wind coloured yarn from hanks, O (as represented on the left-hand side of the diagram), when the amount of work required of that kind would not justify the purchase of a “drum” winding machine, which latter is better adapted for that purpose, for reasons that will be explained later.
FIG. 1.
As usually made, a “cop” winding machine contains a tin driving drum, B, passing centrally down the machine, and carrying the driving pulleys at one end of the tin drum shaft A. By means of cotton bands, C, the tin drum drives four rows of spindles, D, arranged in two zigzag rows, one on each side of the machine, as shown in part plan (detached). Warpers’ bobbins, E, fit loosely upon the spindles, and rest upon metal discs, F, secured to the spindle-shanks, by which bobbins are frictionally rotated. During winding, yarn passes from cops, G, or other source, over a drag-board, H, through a brush, I, and clearer guide, J, thence over a glass rod, K, surmounted on guide-rails, and on to warpers’ bobbins, E. The drag-board H is covered with flannel to impart frictional resistance to yarn, and thereby prevent its passing too freely and making soft bobbins. The clearer guide (of which a front view is shown, detached) is a thin metal plate containing a number of vertical slits, L, from near the top of which are two short slits, M, branching upwards at an angle of about 45°. The vertical slits serve to guide threads to their respective bobbins, and also to remove any irregularities, as “slubbings” (i.e. thick, soft places consisting of a mass of untwisted fibres). The short slits are intended to prevent operatives from raising threads out of the guides, and so save themselves the trouble and loss of time involved in piecing up broken threads.
Spindle-shanks, D, are furnished with tightly-fitting grooved pulleys, N, termed “wharves,” around which driving bands pass. Wharves on each back row of spindles are usually made one-quarter of an inch larger in diameter than those of front spindles, to cause them to revolve at a slower velocity. The object of this is to enable some compensation to be made for the constantly accelerating pace at which yarn is wound, in consequence of the gradually increasing girth of bobbins by additional layers of yarn. When bobbins become about half full on front spindles, a winder removes them to back spindles to be filled.
If bobbins were allowed to fill on front spindles, the velocity at which yarn would travel towards the completion of winding would impart an abnormal degree of tension to it, and thereby make it more liable to break. It is in consequence of the excessive degree of friction to which yarn is subjected in a cop-winding machine that renders it unsuitable for winding yarn that has been previously dyed and sized.
FIG. 2.
One of the most important parts of a cop-winding machine is the traverse motion to guide yarn between the flanges of a bobbin during winding. These are constructed in great variety, but all belong to one of two distinct types, namely, those governed by cams, and those governed by what is termed a “mangle-wheel.” They are also constructed to guide yarn at either a uniform or variable pace between the bobbin flanges. If the traverse of yarn is uniform, bobbins will be wound with a uniform diameter; but if a barrel-shaped bobbin is required, the movement of guide-rails must be differential—quicker towards the extremities, and slower towards the centre of their traverse, with the object of placing a greater quantity of yarn upon them. Traverse motions are usually designed on the compensating principle, so that guide-rails on either side move in opposite directions at the same time, and a falling rail helps a rising one to ascend, thereby requiring less motive power to drive a machine.
FIG. 3.
One of several modifications of a heart-cam traverse motion is shown in [Fig. 2]. In this motion two heart-cams, Q, are set in opposite direction upon a shaft, P, which is driven by a pinion, R, on the tin drum shaft, A, and a train of wheels, S, T, U, V. The cams operate treadles, W, whereby they fall and rise alternately. The free end of each treadle farthest from its fulcrum is connected by means of straps or chains, X, to pulleys; Y, secured to shafts; Z, extending one on each side of the machine, and carrying several pinion wheels, 1, at intervals. The latter engage with teeth in vertical racks, 2, which serve as supports to guide-rails, 3. Thus, as treadles are depressed, guide-rails are raised in a positive manner; but their return is effected by gravitation. The character of movement imparted to guide-rails depends upon the conformation of the cams, which may be constructed to give either a uniform or differential traverse to guide-rails, as desired.
Another modification of a heart-cam motion is illustrated in [Fig. 3]. In this motion a single cam, H, serves to operate both guide-rails, B, by acting upon two treadle bowls, one of which, K, is placed above, and the other, L, below the cam. Treadle bowl K is carried at one end of a lever fulcrumed at O, whilst the other end, M, is connected to a lever, Q. Through the medium of chains and chain pulleys, lever Q operates the guide-rail on the left, whilst the lower treadle, T, operates that on the right.
FIG. 4.
A traverse motion constructed on the mangle-wheel principle, to wind barrel-shaped bobbins, is represented in [Fig. 4], A pinion, B, on the tin drum shaft, A, drives wheel, C, which carries a small pinion, D. Wheel C and pinion D are carried by a bracket that permits of a slight concentric movement of those wheels to enable the pinion to engage alternately on the outside and then on the inside of the mangle-wheel E, with which it gears. On the same stud as the mangle-wheel is a pinion, F, which engages with the teeth of a horizontal rack, G, which is formed with a curved rack at each end. The curved racks gear with eccentric wheels, H, fastened to shafts, I, which carry chain pulleys, J, to wind up or let off the chains connected to the supports of guide-rails. When pinion D revolves on the outside of the mangle-wheel, the latter revolves until the gap K arrives at the pinion, which immediately runs inside the mangle-wheel and reverses its direction, until the gap L arrives at the pinion, which then runs on the outside and again reverses the direction of the mangle-wheel. Thus, rack G is slowly moved from one side to the other, and by acting upon the eccentric wheels H at different distances from their axes, their rotation is quicker or slower, according as the racks are in gear with them at a point nearer to, or farther from, the centre of their shafts respectively. On the same shafts as the eccentric wheels are a number of chain pulleys on which are fastened chains, M, connected to the supports, 2, of guide-rails, whereby the latter are raised and lowered in a manner determined by the eccentric wheels.
FIG. 5.
Another modification of a mangle-wheel motion is shown in [Fig. 5]. In this motion a wheel, E, on the drum shaft, drives the larger wheel F. The small pinion C turns the mangle-wheel H.
In order to obtain the unequal motion of the rack R, to give the barrel shape to the bobbin, a wheel, A, is fixed on the mangle-wheel shaft a short distance from the centre of the wheel. Another wheel, B, is fixed in a similar manner on another shaft, which also carries a wheel which gears into the under side of the rack. The smaller side of the wheel A gears into the larger side of the wheel B, as shown in the diagram, and as the mangle-wheel shaft revolves, the larger part of A will gradually come in contact with the smaller part of B, and this, of course, will cause the rack to move quicker. When the smaller side of A is in contact with the larger side of B, the guide-plate will be guiding the yarn on to the middle of the bobbin; and when the larger side of A is in contact with the smaller side of B, the guide-plate will be putting the yarn on to either the top or bottom of the bobbin.
FIG. 6.
The small side of the wheel A must be set in gear with the larger side of the wheel B, and the traverse halfway of the bobbin. The pinion C will at the same time be in contact with the middle pin in the mangle-wheel, and the middle of the rack R driving the wheel M.
[Fig. 6] is a part elevation, and [Fig. 7] a plan, showing the essential parts of a drum-winding machine to wind yarn from hanks, W, that have been previously dyed and sized, on to warpers’ bobbins, C. In this type of machine, warpers’ bobbins are held horizontally against the peripheries of a series of revolving drums, B, fixed at regular intervals upon a shaft, A, running centrally from end to end of the machine. Bobbins are held in position by spindles, D, contained in frames, E, which are fulcrumed at F to brackets, G, to permit of bobbins rising as they increase in size. Since bobbins are driven by surface contact with drums, the rate of winding is approximately uniform throughout. Projecting from each bobbin frame is a latch, H, to permit of a hook, I, holding a bobbin out of contact with its drum, whilst an operative replaces a full bobbin with an empty one, or pieces a broken thread.
FIG. 7.
FIG. 8.
FIG. 9.
Yarn is guided between the flanges of bobbins at a uniform pace by means of guides, J, carried upon guide-rails, K, supported in brackets, L, and operated by a heart-cam, M. On the end of the driving shaft, A, is a worm, N, which gears with a worm wheel, O, with which is compounded a pinion, P, to drive wheel, Q, to which the cam M is secured. As the cam revolves, it acts alternately upon two runners, R and S, carried upon studs secured to the sliding base, T, of brackets, L, whereby the latter receive a reciprocal motion, as indicated by arrows, U and V.
Winding Machines for Weft.
When weft yarn is in an unsuitable form to be placed within a shuttle it is usually wound upon paper tubes, or wooden bobbins, by means of one of the many systems of “pirn” winding. The chief parts of the prevailing type of machine used for that purpose are represented in Figs. [8], [9], and [10], which are end and front elevations and plan respectively. Passing centrally down the machine is a tin drum, B, on driving shaft, A, for the purpose of driving a number of wharves, C, arranged at regular intervals on each side of the machine. Fixed immediately above each wharve is a metal pirn cup, D, having a conical interior, for the reception of a pirn bobbin, E. When in position, a long spindle, F, having a heavy head-piece, G, passes through a bobbin tube and enters a rectangular hole in the wharve immediately below. The lower portion of a spindle which enters the wharve is also rectangular in cross-section, and therefore revolves with its wharve. At the same time, bobbins are driven by causing a projection, H, below spindle heads to enter a slot in each bobbin head.
FIG. 10.
Each thread passes from its source, over several stationary bars, to impart the required degree of tension to it, thence over guide-rail, I, by which it is guided up and down (as indicated by arrows, J) between the extremities of a pirn cup, as it passes through an opening, K, in the latter, and on to its bobbin. In consequence of yarn being built upon a bobbin within a conical chamber, a bobbin, with its spindle, rises automatically as it fills with yarn, and when filled it raises its spindle clear of its wharve, and thus stops automatically.
FIG. 11.
Guide-rails, I, are usually operated by means of a grooved cam, L, fixed on a side shaft, M, which carries a worm wheel, N, driven from a worm, O, on the end of a driving shaft, A. The cam acts upon a runner, P, fixed on a sliding rail, Q, in which are formed vertical slots, R, one on each side of the machine. Each vertical slot acts upon a runner, S, secured to lever T, having shaft U for a fulcrum. At regular intervals on shaft U brackets are fixed to support guide-rail I, which rises and falls at a uniform pace in both directions.
In consequence of yarn rubbing against the stationary surface of a pirn cup, it is liable to become burnished, and sometimes injured. Many attempts have been made to overcome that objection by driving bobbins by surface contact with revolving discs, and also by supporting them against conical rollers. [Fig. 11] shows one of several methods of driving bobbins by means of bevelled discs, B, fixed at regular intervals upon driving shafts, A, placed one on each side of the machine. In this machine, as in an ordinary pirn cup machine, a bobbin, C, rises automatically until filled, when its spindle, D, withdraws from a hole in the bolster, E, and slides down a short incline, thereby stopping a bobbin by carrying it from the disc.