Cotton Manufacturing

by Christopher Parkinson Brooks

Sizing Machinery.

The slasher is the machine generally used for applying the size to the yarn; the usual name for the process is taping, a word derived from the old tape frame in use 30 years ago, and handed down to its successor, the slasher. One sizing frame is required for 300 looms, the width of the frame being adapted to the size of beam required for the loom; this is a few inches wider than the cloth. A common size is a 9/8; this makes warps 54 inches wide between the flanges, the drying cylinder face being 60 inches wide; a 6/4 is 60 inches beam and 66 inches on face; an 8/4 = 78 inches and 84 inches respectively.

A sizing frame is of great length, and in three portions—at the back the creel, in the centre the drying, and in front the headstock. (See [Plate IV].)

PLATE IV.—SLASHER SIZING MACHINE. To face p. 40.

Supposing a warp is required of 2480 ends—three beams, each 504, will be taken together with two of 484 each; these are placed in the creel in two levels, and the narrower ones are placed at the back. If they were in front of the broader ones the sheet of warp would overhang the narrow beams. The ends are gathered in one sheet, the layers from the hinder beams passing over the top beams and under the bottom ones, all leaving the creel after passing under the foremost beam and travelling into the sow box. Two contiguous boxes or troughs are used for holding the size—the one farther from the creel, called the size box, receiving the mixture directly from the beck, a regulating valve being fixed on the inlet pipe to prevent the box becoming too full. The sow box is the larger one, and receives the size from an aperture in the bottom of the size box, as well as from a separate pipe. In the bottom of the sow box is fixed a boiling pipe of elliptical form, perforated with small holes, through which steam is forced into the size, causing it to boil, and thus always be in the fittest state for application to the yarn. At about half the height of the box two pairs of rollers are fixed, the back pair having the bottom one of wood, and the top one of iron, covered with flannel and cloth; the front bottom roller, or finisher, is of copper, having resting on it a heavy iron one, likewise covered with several layers of flannel and two of cotton cloth. On the firm and even surface of these rollers depends, to a great extent, the quality of the sizing. Between the wooden roller and the end of the box nearest the creel is a copper immersion roller, its use being to lower or raise the warp in the size by means of a rack and pinion. The warp ends coming up from the beams pass under the immersion roller, thus being soaked under the surface of the boiling size, thence between the first and second pairs of rollers—the object of these being to press out all superfluous size and imbed into the thread that which is required. Immersing the thread deeply is advantageous for heavy sizing, although, by simply dipping it, the fluid only attaches itself to the outside of the thread. Better results could be obtained by pressing the yarn whilst under the surface. An example of the hollow india-rubber ball illustrates this. If a punctured or slit ball be immersed in water, without pressure, little or no fluid enters it; but if, whilst under, it is squeezed, the air is expelled, and, on expanding, the surrounding water enters, filling the cavity. Similar results can be obtained by expelling the air from the interstices of the yarn whilst under the size, and patents have been taken out for suitable apparatus. This point is worthy the attention of machinists. Unless well boiled, size retains a granular nature, causing faulty cloth; to obviate this, many machinists insert between the size beck and the sizing frame an extra boiling apparatus, so arranged by the intervention of pipes to boil the size under pressure, impinging steam against the particles of size as they enter the box, thus breaking the globules. After boiling thus, the size enters the box in the ordinary way. To lay the fibres on the yarn a few sizers have recourse to revolving brushes acting on the thread directly after passing the finisher roller. These revolve about 700 revolutions per minute, considerably faster than the warp speed. They are considered advisable for fine reeds and fancy goods.

Adverting to the process of sizing the warp, we come now to the drying; this is done by means of two tin or copper cylinders about 7 feet and 4 feet diameter respectively, the larger one being nearer the front of the frame (see [Plate]). Steam at a low pressure is admitted to these, and both are enclosed in a wooden case. The sheet of warp passes over the smaller cylinder without touching it, and round the larger one; leaving this at the bottom, the twist is next led over the small cylinder and passes to the front of the frame under both. Thirteen or fourteen yards of warp are always drying. Although the moisture has been expelled, the twist is now in a very hot state, and on its passage into the headstock a couple of fans are used for cooling purposes. Systems of drying by currents of air have been introduced, but seem to take no hold in the cotton industry. It is important that the surface of the drying cylinders be kept smooth.

FIG. 12.

The headstock of the slasher consists of framework, holding the rods and reed necessary for separating the sized threads, and the apparatus for winding the yarn on the weavers’ beam. This latter operation comprises the driving of the whole machine, as all the actuating power is transmitted from the headstock by the pull exerted at the front of the machine. By iron rods the sheet of warp is repeated horizontally into as many layers as there are back beams; then, by means of an expanding comb, the rods are separated vertically; thus each being sundered from its fellows, no possibility of “sticking” remains. The split rods are shown in [Plate IV].

The most effective mode of winding the yarn on the beam is shown in section at [Fig. 12].

FIG. 13.

Power is received by the main shaft carrying the cone drum, and transmitted by a strap cone drum; this in turn drives by a pinion the wheel fixed on the friction roller (the largest of the three rollers at the upper part of [Fig. 12]), which is thus positive driven. It also drives the beam shaft, but not positively; the only connection between the cog wheel A, [Fig. 13], and the shaft on which A rides loose, is by means of the friction plates L, between A and B, and A and C.

Unless these are compressed so as to clip a felt washer, the beam is not driven at all, so that it is very easy for the sizer to regulate the tension at which his yarn shall be wound by moving the weight H on the lever G, which presses the positive driven plates B and C against the friction driven plates L L, bringing them into closer contact and thus speeding the beam, consequently tightening the yarn.

The friction roller is a shade larger in diameter than the finishing roller in the sow box, and is connected with it by a long side shaft, each roller revolving at the same speed; the yarn is consequently kept sufficiently tight during the whole process.

In the old style of frame, without the above-mentioned friction, cone drums were used for regulating the speed of the warp. As the beam increased in diameter, one revolution meant a greater length of twist wound on, and the strap had to be moved along the cone drums to diminish the number of revolutions of the beam per minute, and thus keep the speed of the sheet of warp constant.

Numerous presses are used to get a hard beam with a greater number of cuts on it. Although, when extremely hard, the weaving is more difficult, the advantage of fewer gaitings of beams in the shop, doffings at the size frame, and less waste is adequate compensation. These presses generally consist of one or two rollers resting on a stand under the beam in the frame. By weighted levers the stand and rollers are forced upwards against the beam, and keep it hard whilst winding. [Figs. 14] and [15] represent plan and section of this presser.

The duties of the slasher, or, as he is more frequently called, the taper, are to keep the size of proper boil and density, so as to obtain a constant weight of cut, to keep the twist pieced, and doff the beams when filled. In some operations it is necessary to stop the frame for a few minutes, and although the stopping handle is connected with the cylinder steam pipe to prevent further admission of steam to the cylinders, these remain so hot as to brown the twist.

FIG. 14.

FIG. 15.