COTTON-SPINNING MACH:NEM% To show more plainly the advance in cotton spinning machinery during the past ten years, it may be well first to state in a general way the operations that are at the date of this work in use in converting the cotton in the bale to the warp on the beam, or the tilling on the (!op or bobbin, ready for weaving. The cotton is received at the mills in compressed bales. containing about 500 lbs. each, and generally con fined by ropes or iron bands, and sacking. In this cotton is a very considerable amount of leaf, sand, and seeds, and sometimes other foreign substances. The first operation is the opening, of the bales and the mixing of cotton. which is done by hand, so as to secure a com parative evenness of fiber. A number of bales arc opened at once, and the mixing is supposed to be thorough. Prom the heap of cotton so mixed it is taken to an opener, where it is sub jected to the action of beaters and fans, and delivered in rolls called laps. Two or more of these laps are then fed to a finishing lap per, where the beating operation is again gone through, and the lap from this machine is the completed product of the picker-room. The cotton at this stage has been freed from the larger portion of the foreign matter, and the fibers have been thoroughly disentangled.
The next operation is that of carding, which is a very important one, and perhaps not yet thoroughly understood. The lap from the picker is slowly fed into the carding-machine, in which is a revolving cylinder covered with ('lot ldng. containing teeth, by which the cotton is carried past either stationary or movable surfaces, also containing teeth, and deposited upon another cylinder called a dolfer, from which it is taken off in a thin sheet by a comb. The card continues the cleaning of the cotton, and thoroughly disentangles the fibers, and places them in a condition in which they can be easily straightened, It is stated, in most books of reference, that the cards straighten the fibers; but any one who will examine with a glass the sheet that comes from the duffer will be satisfied that the fibers lie in anything but parallel directions. They are so disposed, however, that straightening be comes an easy process in the drawing to which the fibers are afterward submitted. Where carding is well done, the fibers are thoroughly disentangled, and the sheet is free from lumps, technically called nuts. There are two kinds of cards. in huge use on cotton: the stationary flat card, and the revolving flat cord ; the latter being quite generally known as the English flat card, though now manufactured by several American shops. The revolving flat card is said to do the largest quantity of work, but that is asserted by the friends of the other card to be due to the use of larger cylinders. It is also claimed that the revolving card makes less waste. There is no doubt that. there is a better feed in use on the revolving flat than on the ordinary card as previously built. Another important point is this: the flats of the common
card have to be raised at stated intervals to be cleared from acemnulations of dirt and fiber. When they are raised an opening is left, in which the flyings from the cylinder collect, to the detriment of the work when the flat is replaced. With the revolving flat the cylinder is always covered, and the flats not in use are thoroughly brushed out, between their service at the rear side of the cylinder and their next service at the front side. The cotton leaving the Card is, with the revolving flat card, gathered together into a strand, and run into a can. Where the ordinary card is used, the strand is fed into what is termed a railway-box, where, with other strands, a sheet is formed, which is carried by a hell to what is termed a railway bead, where it is reduced in size of strand by drawing-rolls, and subjected to the action of an evener.
The next, operation is known as drawing, which is done to complete the straightening of the fibers of the cotton and to reduce the sliver, the technieal name for the strand in this condition in size. Besides this. the strands are doubled over and over again before being drawn, to equalize the diameters of the resulting strand. The theory is that by doubling, large places in one strand are likely to come opposite small ones in another strand, and the general average of size be improved. Too much drawing, however, weakens the material, and there is considerable question among manufacturers as to the proper amount. Where the English card is used, the cans front the card are set np behind the drawing,-frame : and where the railway-head system is used, the cans from the railway-head an' placed in that position. The material is delivered from the cans on one side of the frame through the drawing-rolls to cans on the other; the diameter of eons being generally reduced with the diameter of the strands. The iiroeess of drawing was the invention of Arkwright. and it consists in subject ing tlie material to the operation of several pairs of rolls. the front ones of which revolve more rapidly than the rear ones, and thus elongate the sliver and correspondingly reduce it in diameter. Prom one to three sets of drawing-frames are now in use in most mills. The sliver at the last drawing-frame is made as small its it, is sure to hold together in being drawn out of the can, To (motile it to he still further reduced, it is necessary to introduce twist in the next processes. .Machines by which this is clone are called, in general terms, roving-nunehines, and their product, is known as roving. These maehines, like the drawing fount', draw the antlii still smaller, and olimmunieate twist to it by means of revolving spindles with their fliers. and wind it upon bobbins.