Cotton spinning

“ The opener, then, is a very powerful machine, being in fact the most powerful used in cotton spinning, and the most important feature of the machine is the employment of a strong beater, to which is fitted a large number of iron or steel knives or spikes. These beat down the cotton and open it at a terrific rate, the beater having a surface speed of perhaps 4000 feet a minute. Various fans, rollers, and other parts are employed to feed the cotton to the beater, and to take it away again after treatment. ”

“ The distance from the face of the grids to the ends of the beater blades should be carefully arranged to suit the class of cotton treated, as, if it is too great, the opening is not properly effected, and, if too little, the cotton is liable to be damaged. The rate at which the feed is conducted should always be carefully watched, because, if the material is passed in too quickly, its bulk becomes so great in the lower part that the dirt cannot fall freely, but is received by the entering cotton. ”

“ It is of extreme importance to produce laps at an early stage, as they play a great part in effective spinning. Before dealing with this point a few words may be said about the necessity for care in feeding the cotton. The fibre is easily ruptured, more especially at the points, which, owing to their distance from the seed during growth, are often solid. It is conceivable that the cotton might be fed at precisely the same speed as that of the periphery of the beater blades. ”

“ The fibres have a small bore and thick walls, and are, in addition, only slightly twisted. The worst Indian fibre is Bengal, which is short, strong, and dirty.
(23) Commercial qualities. The recapitulation of the principal features of various growths of cotton just given enables their relative value for spinning to be pointed out, and at the same time to indicate the qualities it is desirable to retain during the subsequent mechanical treatment. Sea Island cotton is beyond doubt the finest quality existing, and, in the manufacture of fine counts, is absolutely essential. ”

“ Thus the retardation of the cotton in the one case leads to any extra thickness being rapidly beaten out, more blows being given to the same length fed than would be under ordinary circumstances. On the other hand, a thin place results in the quickening of the feed roller and a greater quantity of cotton is beaten off in the same time. In this way an evenly-weighted delivery takes place, and this, in conjunction with the lap feed, of which more will be said hereafter, enables a lap to be finally produced, in which the variations of thickness are comparatively slight. ”

“ In conducting the manufacture of cotton into yarn, it is desirable to remember that a gradual reduction in its substance is wanted, and all the draughts throughout the whole series should be carefully graded to ensure this. It is extremely undesirable to overstrain the cotton at any point, and this would be the inevitable result, unless the whole of the speeds were designed to give a gradual reduction. ”

“ Viewed in this light, Egyptian cotton is the strongest, and this fact, in conjunction with certain other qualities to which attention will afterwards be called, renders it of high value. It only remains to be said that a waxy covering is found on the outside of each fibre, which requires to be softened by heat during spinning so that the flexibility of the fibre may be fully maintained. ”

“ The white fleecy cotton, reposing like a wreath of snow upon the bronze red skin of the hand and wrist, is gradually carried to its farthest extent one way, whilst drawing from it the long slender thread, the other hand conducts, in an opposite direction, the short thin reed tipped with a piece of ivory or horn that forms the reel, which spinning as it hangs, its effect upon the thread depends upon the slowness or quickness with which the cotton is drawn out. ”

“ SPINNING AND WEAVING Judging by the great number of spindle-whorls found in the mounds and on village sites, cotton spinning must have been practically universal among the women. Oval perforated stones of a size suitable for loom weights have been found, and it is probable that they were used as such, as they do not seem to be adapted to any other purpose. ”

“ A much better method is adopted by Messrs. Platt Brothers and Company, and is shown in Fig. 33, which illustrates the new practice. It will be seen that, when the beater strikes the cotton directly from the pedal nose, the fibres will be bent sharply round an angle. In the case of long-stapled cottons especially this is detrimental, as it is liable to lead to rupture or breakage of the fibre. With the shorter-stapled varieties this is not so likely to occur, and the use of a pedal and feed-roller is more permissible. ”

“ The cotton fibre is a hollow tube of cellular construction, and is of an oval or flattened cylindrical shape. Ripe or fully matured fibres of the best cotton are convoluted or spirally twisted on their axis, and the edge of such a fibre presents a corrugated appearance. The regularity of the convolutions, or twists, is greatest in the highest class of cotton, and reaches its lowest point in the poorer grades. One important effect of such a formation is that each fibre naturally tends to coil round its neighbour, and thus lends itself to spinning. ”

“ In the scutcher the doubling of four laps together tends to produce a sheet of cotton more uniform in thickness and weight than that from the opener. This object of equality of lap is also invariably aided by what are termed Automatic Feed Regulators, which regulate the weight of cotton given to the beater to something like a continuous uniformity. The action is clearly seen in the illustration.
Carding.—By many persons this is deemed to be the most important operation in cotton spinning. Its several duties may be stated as follows:—
1. ”

“ A dirt chamber is, as usual, formed below the grid. The cotton is fed by a lattice and feed rollers. The latter are formed in the ordinary way, with a number of circumferential V grooves, crossed by a series of similar longitudinal grooves, so as to form a large number of teeth, which securely hold the material as it is fed. As the cylinder revolves 1,000 times per minute, the teeth strike the cotton and disentangle the fibres, throwing them with considerable force against the grid. ”

“ The manipulation of the cotton is now so largely automatically performed that there is much less difficulty in keeping a mill clean than formerly. It should be the aim of every spinner to diminish the handling of the material as much as possible, and students of this subject should remember that it is never too early to begin to deal with the cotton so as to prepare it for subsequent treatment. Efficient purification at an early stage is a great help towards economical and efficient spinning. ”

“ The drawing machine in cotton spinning aims at removing the weak places in cotton thread, thus making the real strength of the thread vastly greater than it would otherwise be.
The method by which these important objects are attained may be briefly explained as follows:—
From four to eight, but most usually six, cans of sliver from the previous machine are placed behind the frame, and the ends of the slivers conducted over special mechanism within the range of action of four pairs of drawing rollers. This [Pg 102] passage of the cotton is shown very clearly in Fig. 17. ”

“ Thus, the harsh, wiry varieties of cotton stand more drawing, but if well drawn will spin fairly well into weft, which does not receive so much twist as warp, and should be full bodied. How much any class of cotton should be doubled and drawn is a matter to be determined by practice only, and even then great variations in the course pursued will occur. The one thing which must be remembered is that as soon as an even sliver is produced further drawing is unnecessary, and only results in a diminution of the strength of the spun yarn. ”

“ In dealing with the fibre by revolving beaters of any kind, two things are essential to success. First, the blow given must be of such a character that the fibres are completely separated, while any rupture or breakage of them is avoided. Second, the surface against which the cotton is flung after being struck by the beater, must be arranged to permit of the free passage of all impurities, while, at the same time, so arresting the movement of the tufts or pieces of cotton as to shake out the extraneous substances. ”

“ From a consideration of spinning we arrive at a definition of the manufacturing processes.
Unlike the spinning which is carried on in a building five or six storeys high, the manufacture of cotton goods takes place in a “shed,” as much of the work as is possible being carried on on the ground floor. The weft yarn, or that which is laid transversely in the cloth, leaves the mule in the condition in which it is required at the loom, but the twist or warp yarn passes through several “preparatory” processes to fit it for the operation in the weaving ”

“ An excess of suction further results in the cotton fibres being drawn into the interstices of the cage surface, and the fleece does not in that case leave the latter easily. This results in a rough surface of the lap, and leads when it is rolled up to “licking,” or adhesion of the different layers.
(79) It is therefore desirable to get the draught as nearly balanced as is consistent with the required onward movement of the cotton. What is wanted is rather a large volume of air moving at a slow pace than a smaller one travelling more quickly. ”

“ Cotton weaving extends no further into Yorkshire than Todmorden, and about 2,000,000 spinning and doubling spindles are in use about Halifax, Brighouse, Sowerby Bridge and district, these being employed on yarns for dress fabrics made of a mixture of cotton and worsted, as well as for curtains and hosiery in the Nottingham and Leicester districts. In Scotland, the cotton trade is confined to the counties of Lanark, Renfrew and Ayr. The spinning trade is here going down rapidly, there only being about one third the number of spinning spindles running this year (1888) , as compared with 1857. ”

“ It has been found that the use of under casings with the licker-in has been attended with considerable economy. They are also used beneath the cylinder, and should be as carefully set as is the case with those under the licker-in. In determining the distance, regard should be had to the quality of cotton used and its length of staple, as, if the fibres actually strike the bars of the grid, they may adhere to them and partially choke the latter. On the other hand it is found that too wide a setting is followed by increased waste. ”

“ But perhaps the seat of the cotton manufacture of the future may not be wholly where the cotton grows. Cotton is a sun plant. It thrives best and yields the largest product in the hot, dry years when the dryness does not become a drought. The very characteristics of climate which promote the production of the fiber are to some extent inconsistent both with spinning and weaving, which call for a cool, moist atmosphere. ”

“ Some have not done well owing to defective management. But others are working day and night. The importation of raw cotton has quadrupled in the last three years, while that of cotton on the seeds has doubled. A million dollars worth of the most improved British spinning machinery was laid down last year, and much attention is being given to the cultivation of the cotton plant, although, owing to the typhoons, with indifferent success. ”

“ A more important result, however, is that if there be any unevenness in the diameter of the yarn, the twist speedily runs into the thin places, which become hardened, and do not easily elongate or draw. The thicker places remaining untwisted are, therefore, drawn down until the full twist runs into them also. This supplementary twisting231 and drawing is called “jacking,” and its amount varies, of course, with the staple of the cotton being spun, the further movement of the carriage being sometimes as much as five inches. ”

“ The better the staple of the cotton wool, and the more careful has been its preparation in the carding, drawing, and roving processes, the more easy and excellent the spinning will become: warmth, dryness, cold, and moisture have great influence on the ductility, so to speak, of cotton. A temperature of 65° F., with an atmosphere not too arid, is found most suitable to the operations of a spinning mill. The finer the yarn, the slower is the spinning. For numbers from 20 to 36, from 2 to 3 stretches of warp may be made in a minute, and nearly 3 stretches of weft ”

“ The mixing should be made with reference to the kind of yarn required, whether for warp or weft, coarse or fine, &c., and the sorting of the cotton for this purpose requires experience and good judgment. Some cottons, particularly those of long and short fibres, cannot be made to draw, rove, or spin well together. The cotton taken from the bing is too impure for spinning until it has been passed through several processes, by which the dirt is winnowed out and the matted lumps are opened and the fibres loosened and cleaned. ”

“ The cotton plant. On the river Derwent near Matlock in Derbyshire, Sir RICHARD ARKWRIGHT has created his curious and magnificent machinery for spinning cotton; which had been in vain attempted by many ingenious artists before him. The cotton-wool is first picked from the pods and seeds by women. ”