Beam-warping.
Three methods of warping are in use, but far ahead of the others in production stands the beaming system. To enable a sufficient number of threads to be gathered in one sheet for sizing purposes, say 2000, it is necessary to wind them first on a warper’s beam. This is a round roller, of wood, five inches in diameter, having an iron flange 20 inches diameter, and also an iron pivot at each end. This will hold 500 ends, each 15,000 to 20,000 yards in length, so that for a cloth of 2000 ends four beams are required at the sizing machine.
The beam-warping machine is for the purpose of warping the yarn from these 500 bobbins to a beam.
The bobbins from the winding frame are placed in a creel, generally a [V] creel, and shaped in plan view as its name indicates, each arm of the [V] being a frame containing tiers of pegs to hold 250 bobbins, the apex being nearest to the frame. The yarn passes through a reed, under and over several horizontal rollers, emerging in front through a guide comb, and thence to the beam. The beam is driven by friction, resting on a large drum making about 50 revolutions per minute; therefore, whatever the size of the beam may be—i.e., whether full or empty—the yarn, being pulled at the front, is travelling at a constant speed.
To avoid sudden strains of yarn the creel does not rest on the floor, but is suspended from overhead beams by rods. The older makes of beaming frames have a bed creel. Only one vertical creel is used, the other half of the bobbins being fixed in a horizontal frame. The [V] creel is preferable.
The whole frame occupies a space of about 16 by 18 feet.
The guide comb is of interesting construction. It is capable of expansion or contraction. Each tooth of the comb projects from an iron box, and is kept in position by being passed through the coils of several spiral springs; by means of a screw and nut at each end these springs can be compressed, thus diminishing the distance between the comb-teeth equally at all parts of the comb. When the expanding combs are used, far leveller beams are made than are otherwise attainable.
In the event of a thread breaking, the warper must have some arrangement for running the yarn back, so as to find the broken end to piece it up. This is obtained by six falling rods placed above seven fixed ones. When the machine is running forward the sheet of yarn passes between the fixed and loose rods, the latter resting on a slide. When the machine is reversed, the slide receives a slight impulse, allowing one rod to drop, say 3-1/2 feet, the yarn being suspended at the top by the fixed rods; whilst this rod is dropping it pushes the slide still further, and another drops, and so on, until when the sixth rod has fallen, twelve times 3-1/2 feet equalling 42 feet of yarn are taken up. This is ample for piecing purposes; indeed, the woman in attendance seldom finds it necessary to go so far.
FIG. 10.
FIG. 11.
PLATE II. To face pp. 26 and 27.
Prevention, however, is better than cure, and several machines are on the market fitted with stop motions to arrest the action of the machine at the breakage of a single end, and reducing the number of falling rods to two. One favourite system is to have a small bent wire, not unlike a hairpin, but about 1-1/4 inch in length, suspended from each thread and held in position by slots across the frame. This system is shown in [Plate II.], [Figs. 10] and [11]. Immediately under these pins are two nip rollers M ([Fig. 10]), revolving in contact, one of them borne on a movable centre, and attached to an upright lever N. This is immediately above an upright slide I, the bottom of which is connected to one end of a lever centred on the drum shaft of the frame. At the other end of the lever is a foot board and also the connection of a long rod with heavy balance weight always tending to press the footboard up, and consequently the slide down.
The machine is driven by a single open strap on the pulley, which, however, does not actuate the machine until it is pressed against the friction plate.
To start the machine, the footboard is pressed down, the slide consequently lifted and held in position by a hook which catches on the framework. By an inclined collar J, on the centre of the lever H ([Fig. 11]), the friction pulley and plate are pressed into contact and the machine is in motion. When an end breaks, the hair-pin drops between the nip rollers, pressing the loose one away from the other, therefore by means of the upright lever already referred to knocking off the catch H ([Fig. 10]). As soon as this is done the slide drops, and with it the lever O. The inclined collar relieves the pressure on the friction plate and the machine stops. The attendant pieces the broken end which is thus brought under his or her notice.
Beam warping machines are of various sizes, the most common being for 504 bobbins, the width being 9/8ths, or 54 inches between the flanges of beam. Other widths, of course, are in use, from 44 to 108 inches.
The waste of yarn, in the preparatory processes, indeed in all departments of mill work, is extremely important, and should be kept at as low a percentage as possible. At the winding frame the total waste should be 1 to 1-1/4 per cent., varying with the count and quality of yarn, and the total waste of warp yarn throughout the mill should not exceed 1-1/2 per cent. at the most.
For the purpose of measuring the length of yarn on the beam, each warping frame is supplied with a roller half-a-yard in circumference, round which the yarn passes; on the end of this roller is a worm driving a worm wheel B, of 54 teeth; on the stud carrying B is a second worm C, driving a worm wheel of 132 teeth. The worm only takes one tooth at each revolution, therefore a complete revolution of the first worm wheel represents a length of 27 yards having passed the measuring roller; this is equal to one tooth only on the second wheel B; therefore, a complete revolution of the latter means 3564 yards—technically called a wrap—1/2 × (54 × 132)/(1 × 1) = 3564. If a warp contains 4 wraps and 7 teeth, it is 14,445 yards long - 4 × 3564 + (7 × 27). For other warping calculations see Chapter IX.
The faults in beams are principally, bad, or no piecings, soft places caused by fine threads, or ends unevenly distributed in the combs, or by crooked flanges.
Where dhooties and other striped cloths are made, the warper has to be provided with a sheet showing how the coloured yarn is “laid in” at the side. This will be described under the heading of Dhooties. Where possible, all the coloured yarn is placed on one beam of the set, leaving the other beams all “grey,” as the undyed yarn is termed.
In any case of warping two counts of yarn on one beam, whether coloured or grey, allowance must be made for the different diameters of the threads.