wool is loosened by application of a thin lime paste to the back of the skin, or by sweating the wet skins in piles.
The three main classes of wool on the basis of the staple are: (1) carding or clothing wools, or those of the Merino type, in which felting qualities are desired; (2) combing wools, in which length of staple is required and felting qualities not desired, used for hard-spun non-felting worsteds; and (3) miscellaneous, sometimes called carpet or blanket wools, long, strong, coarse wools, used for carpets, blankets, and coarse clothing. The clothing wools are commonly classified as picklock XXX, XX, X, picklock being an extremely fine fibre. The mass of high-grade clothing is made of the XX and X grades. The combing wools, often called Delaines, were formerly derived from the English mutton breeds, but machinery has been adapted for combing the Merino carding or felting wools, which have been lengthened by breeding and selection. The clothing wool used in the United States, aside from home production, is derived mainly from Australia, South America, and South Africa. The imported combing wool comes mainly from Great Britain, although much comes from New Zealand, Argentina, and Canada. The coarse carpet wools are the product of neglected flocks and unskilled breeding throughout the world.
In judging wool on the sheep's back, account is taken of strength of fibre, fineness, curl, thickness, and closure of the fleece. When the yolk is deficient the fibres become dry and brittle, and the fleece is likely to be injured otherwise. The waves of the curl should be uniform and numerous throughout the length of the fibre. The thickness of the fleece, depending upon the closeness of the fibres upon the skin, varies greatly with the breed, and also with the individual to some extent. A fairly thick and well-closed fleece is desirable. The closure is caused by the matting together of the ends of the fibres by the yolk. This gathers dust and forms a dirty coating, rendering the fleece impervious to dust and dirt, which would be injurious.
As a result of the tendency toward combing wools, both fine and coarse, Merino and English worsted wools now largely predominate in the domestic supply. Since all the improved breeds of the world have been introduced and acclimated in the United States, the range of grades of wool which have been successfully produced is very great. Breeding, care, and feeding have more than doubled the average weight of the fleece, the present average for all classes being about six pounds. Among well-tended flocks of mutton breeds, which produce a heavier fleece than the fine-wooled breeds, the yield amounts to 8, 10, and more pounds per head, in individual cases reaching or even 20 pounds. In most parts of the United States shearing is done in the spring; in Texas, New Mexico, Arizona, and southern California, where climatic conditions interfere to prevent evenness of fibre, it is done twice, the winter fleece being stronger and of greater value than that grown in summer. Since these clips do not work well together, their mixture reduces both qualities to a low level.
Defects of Wool. The most common defect of wool is ‘break,’ which is due to exposure, insufficient feeding, etc. In this the fibre contains weak spots which cause it to break when stretched. It destroys the value of wool for combing purposes. ‘Stripy’ wool is inelastic, harsh, and lacking in curl, and is used only to make inferior goods. It affects the fleece in the most valuable part—the sides and shoulders. ‘Toppiness’ is a sort of uneven felting of the fibres at the top of the fleece, so that the closure is not perfect. It is usually the result of uneven growth, and causes waste in carding. Felted wool is deficient in yolk, and as a result becomes matted together in bunches, causing loss in combing and carding. It is attributed usually to poor health. Broad-topped wool is a serious defect, in which the fibres split down from the top, interlace and mat so as to appear even on the surface, which is divided into broad masses called ‘tops.’ These cannot be parted without tearing. ‘Hemp’ or ‘kemp’ consists of a mixture of short, coarse white hairs and wool fibres, occurring chiefly on the parts where the wool is lightest and shortest, but may occur all through the fleece if the sheep has a tendency to produce hemp. Since the hairs do not take dye and cannot be sorted out, they lessen the value of the fleece fully one-half for the manufacture of fine grades of goods. In cloudy wool the fibres adhere throughout their length, but not so much as to be felty. This injures the wool for combing, causing waste, but is not so objectionable in carding wools.
Wool-Sorting. The differences in the quality of wool, and especially that from different parts of the fleece, render sorting a necessity. In shearing, the fleece from each sheep sticks together as a mat, and is tied up separately. In sorting, the different parts of the fleece representing separate qualities are torn off by hand. An idea of the location of the various qualities of wool is given by the accompanying diagram of a Leicester lamb's fleece, taken from Bowman's Structure of Wool Fibre. The same relative positions hold good in all kinds of fleeces.
FLEECE OF LEICESTER WOOL.
The finest and most even growth of wool is found at A, on the shoulders. In some fleeces this quality extends farther up the back (E) and toward the tail (B and F) than in others, and the quality of the wool at B is not very much inferior, although rather shorter and coarser.
