When the cotton arrives in bales at the mill (see [Fig. 10]), in which it is to be cleaned, opened and spun, it is first weighed and a record kept.
In the mill the first real operation is the taking of quantities of cotton from different bales of cotton from various countries, or different grades from the same country, and "mixing" so as to secure a greater uniformity in the quality of the yarn produced. In this process it is now the common practice to use a machine termed the "Bale Breaker," or "Cotton Puller."
The second important process carried out in the mill is "opening." By this the matted masses of cotton fibres are to a great extent opened out, and a large percentage of the heavy impurities, such as sand, shell, and leaf, fall out by their own weight. It is now also usual at this stage to form the cotton into a large roll or sheet called the "lap."
Immediately following the "opening" comes "scutching," which is merely a continuation of the work performed by the "opener," but done in such a way that greater attention is bestowed upon the production of an even sheet or "lap" of cotton.
The cotton at this stage is practically in the same condition as it was when first gathered from the tree in the plantation.
Carding comes next in order, and it should be observed that this is one of the most beautiful and instructive operations carried on in the mill.
The process of opening out the cotton is continued in this operation to such an extent that the fibres are practically individually separated, and while in this condition very fine impurities are removed, and many of the short and unripe fibres which are always more or less present are removed. Before leaving the machine the fibres are gathered together again in a most wonderful manner and converted into a "sliver," which for all the world looks like a rope of cotton, a little less than an inch in diameter.
In most mills "drawing" succeeds "carding," this operation having for its object (1) the doubling together of four to eight slivers from the card and attenuating them to the dimension of one so as to secure greater uniformity in diameter. (2) The reduction of the crossed and entangled fibres from the card into parallel or side by side order.
After "drawing," the cotton is brought to and sent through a series of machines termed "Bobbin and Fly Frames." There are usually three of these machines for the cotton to pass through, to which are given the names of "Slubbing," "Intermediate," and "Roving" Frames.
Their duties are to carry on the operation of making the sliver of cotton finer or thinner until it is ready for the final process of spinning, and incidentally to add to the uniformity and cleanliness of the thread of cotton.