CHAPTER IV.

MANIPULATION OF THE MATERIAL.

Cotton spinning, definition.-Processes defined: ginning; packing; mixing; willowing; opening; scutching; carding; combing; drawing; slubbing; intermediate; roving; spinning; doubling.-Cotton testing; test-book; mixing-book.-Hand-labour superseded by machine-labour; the operative a superintendent.-Cotton spinning: preparatory and constructive processes.-Mixing; preliminary examination and classification of the cotton; large mixings better than small ones; importance of securing equal lengths of staples; process of mixing; testing; mode of using; prescribing mixings; mixing in the lap.-Willowing or opening; general principles; the Oldham willow, common and improved; the Crighton opener and its operation; the porcupine; the pneumatic feeding opener; an American opener.-The purposes of opening.-Injuries arising from adulteration.-Injuries from excessive willowing.-Imperfections of the willow; better principles of the Crighton and the pneumatic feed openers.-Scutching, its purpose; importance of correct feeding in the scutching machine; the scutching machine, hand-fed; trustworthy attendants; automatic weighing.-Influence of temperature and atmospheric states on the weight of laps.-Lap-feeding; the piano feed, its action. The finisher lap machine, its function; description.-Well made laps; causes of unequal laps.-A new automatic feed suggested. -Clayton's lap roller.-Remarks: qualities of this class of machines ; speeds; construction; cleansing; oiling.

HE practical details of the art and the machinery employed in it now demand consideration.

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The manipulation or mechanical treatment of cotton in all its processes up to the production of a cloth, after ginning and baling in the country of growth, takes place in the cotton mill. An enumeration and brief definition of these processes at this point will obviate much repetition.

"Cotton spinning" implies in the aggregate every operation involved in transforming raw cotton into yarn

that is, into a single twisted strand or thread composed of cotton fibre. "Spinning" has also a more restricted signification, being used to denote the concluding process of the series.

The writer, in another place,' has defined the processes of manipulation, mechanical and otherwise, that cotton undergoes in being converted into yarn from the state in which it is gathered from the plant, as follows:

1st. "Ginning."-This is usually performed in the vicinity of the cotton plantation, the object being to remove the fibre from the seed of the plant, and partially to cleanse it from foreign matters.

2nd. "Packing" or "Baling."-After ginning, the lint is in a loose state, and unfit for convenient transport to distant markets; hence it is necessary to compress it into less space, which is ordinarily performed by means of hydraulic presses. The package leaves the press in the well-known form, technically called a bale, in which state it passes through the markets to the hands of the spinners.

3rd. "Mixing" is the blending of different varieties of raw cotton, in order to secure economical production, uniform quality and colour, and an even thread in any desired degree. Even when using only one class or variety of cotton, mixing is in a measure imperatively necessary, in order to neutralize the irregularities of growth and imperfect classification found more or less in all grades of cotton. It is the first operation in a cotton mill.

4th. "Willowing."-This is a process of opening and cleaning cotton which, except in the Oldham district, is not much in vogue in modern mills, and is retained chiefly for opening and cleansing low cottons, waste, &c.

5th. "Opening."-In consequence of the heavy pressure to which cotton is subjected in packing, the fibres become strongly matted together; the opening process is to

Art. "Cotton Manufactures," Spon's "Encyclopædia of the Industrial Arts, Manufactures, and Commercial Products."

loosen them, and to remove the heavier portion of the foreign substances that may be intermixed. It is the present equivalent of willowing.

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6th. "Scutching" has a two-fold object, namely, the further extraction of impurities, and the formation of a lap," which is a web or sheet of cotton formed in the machine, and wound upon a small roller. In this web the fibres lie in all directions.

7th. "Carding."-The foregoing operations have dealt with cotton in the bulk. In carding, the process of opening is continued, but the material is treated in its individual fibres, which are taken from the lap, further cleansed, and laid in a position approximately parallel to each other, forming a thin film, which is afterwards condensed into a sliver a round, soft, and untwisted strand of cotton. In this process all short, broken, and immature fibre is, as far as possible, removed.

8th." Combing" is used for the production of fine yarns, or those of high quality. Its object is to obtain uniformity in the length of the fibres undergoing preparation. To accomplish this, all those shorter than the required standard are combed away and rejected. It is not ordinarily used for any but the above purposes.

9th. "Drawing."-In this operation, several sliversthe product of the carding process-are combined, and attenuated to the dimensions of one of the component parts. The objects are to render the new sliver more uniform in thickness, and to place the fibres more perfectly in parallel order.

10th. "Slubbing " is a process by which a further combination of slivers is effected, and the objects of drawing are more perfectly accomplished. The drawing or attenuation of the strand is now carried so far that it becomes necessary to twist it slightly, in order to preserve its cohesion and rounded form.

11th. "Intermediate," or "Second Slubbing," is in all respects a repetition of the above, necessary in cases where

the most even and clean yarn is required. It is not ordinarily used in the production of low numbers.

12th. "Roving."-This is a continuation of the preceding, its principal object being to attenuate the sliver still further. At this point, also, the latter receives additional twist, to enable it to bear the slight strain necessary to draw it from the spool or bobbin without the formation of uneven places.

13th. "Spinning."-The concluding process of the series. The sliver is here attenuated to the required fineness, and is given the twist by which the thread is completely formed.

14th. "Doubling," sometimes a separate business, but more often an adjunct to the preceding, is a method of combining two or more threads to form a single cord, and is adopted in the production of many varieties of yarn. which are used for widely different purposes.

The processes thus briefly defined constitute the operations of cotton spinning, and carry us as far in the manufacture of the fibre as it is designed shall be included in this treatise. It will be the object of the writer to describe the best ways and means now in vogue for attaining the end sought by each process, to point out defects where such may be obvious, and, if possible, to suggest improvements.

COTTON TESTING.-It is a customary and a wise proceeding to test each purchase of cotton to find the average loss of weight upon the same classes of the material, or upon the varieties that compose the mixing in use. A small quantity—say 5 lbs.—is taken from each bale, and passed in succession through the scutching machinery and the card, beyond which the test is not carried, as the loss that occurs after these passages is small, and can be easily estimated. The parcel is carefully weighed after coming out of each machine, and the particulars entered into a book kept for the purpose, called the test or loss-book, which thus becomes a valuable book of reference. The 5 lbs. of

cotton, on its passage through the opener or willow, probably loses 3 ozs., reducing the weight of what remains to 4 lbs. 13 ozs. Its next passage is through the scutcher, where it loses 2 ozs. more, the balance being 4 lbs. 11 ozs. The lap machine is the next passage to which it is submitted, and in this it most likely drops 1 oz. more; balance, 4 lbs. 10 ozs. Supposing there to be a finisher lap machine after the last-named, the loss on its passage through this will again be 1 oz. more, reducing the bulk to 4 lbs. 9 ozs., or thus far a loss of 7 ozs. = 83 per cent.

A second useful book in the cotton room is the mixingbook, in which are entered the dates of every cotton purchase, the quantity, marks, and numbers of the bales, and the gross, tare, and net weight of each bale at the time of receipt. If the cotton is suspected of being damp, each bale ought to be weighed again just before being used, and any difference recorded, for which either claims may be made, or the marks avoided in future purchases. The price per lb. of each lot should also be attached, as this is required to ascertain the cost of the mixing. Similar entries must also be made for any waste that may be introduced. In laying down the mixing, the quantity of each sort must be carefully noted, the prices attached, and the calculation extended, the totals added, and the sum divided by the number of pounds the mixing contains, the result being the average cost of the mixing put down. The test sample of the mixing before spoken of will show the percentage of loss upon it, after which the cost is easily calculable.

In the processes of manufacture the human hand, from which the word is derived, and which formerly performed nearly all the labour, has been almost entirely superseded by machinery. Very little is now left for the operative to perform, his or her task being reduced to one of scarcely more than continuous supervision. From the mixing of the cotton to the doffing of the yarn all the labour, strictly speaking, is accomplished by mechanical appliances. It