Worsted yarns, used in making fine Wiltons, body Brussels, Wilton velvets and some chenilles, result from a succession of processes in which the fibers are placed parallel, the short ones eliminated, and the long fibers combed and drawn out into a fine, even "roving," which is spun into a thread, two such threads then being tightly twisted together to form a single-ply worsted yarn. These single-ply yarns are then twisted together to form two-ply, three-ply, or four-ply yarns according to the specifications for a particular weave.
Woolen yarns are made from short staple wool, and depend for their strength upon the minute serrations or scales on the surfaces of the wool fibers, which cause them to adhere, or felt, when held tightly together. The carding machine used in preparing these wools for spinning thoroughly intermixes the fibers instead of drawing them into parallel formations, as for worsteds. The loose roving is then spun into single strands, which are twisted into two-, three-, or four-ply yarns as in the case of worsteds.
Mohair.—The hair of the Angora goat is closely allied to wool, typically 7 to 8 inches long. It is lustrous, resilient, and enduring, but harder to spin than wool because the hair scales are not fully developed. Mohair fabrics have been used in the Orient since time immemorial, and they were popular in England in the early eighteenth century.
There are wide differences in mohair upholstery fabrics, based upon the quality of wool, number of points per square inch, and height of pile.
Horsehair.—The hair of the horse's mane and tail is used as a single filament without spinning in the production of upholstery chair cloths, and for floor coverings. In the form of curled hair it is the most resilient and costly upholstery stuffer.
Pig's bristles and cow hair are used for the same purpose. The soft hair of the camel is used in weaving certain oriental rugs, and rabbit hair in certain felts.
Vegetable Fibers.
Cotton.—This textile is in universal use and requires no comment. The silky appearance of some damasks and other cotton fabrics is caused by mercerizing, a process of treating cotton in either fiber or fabric form with caustic alkali.
Rayon.—This term, which in French means ray or beam, has lately been applied to artificial silks produced by any of four different industrial processes. Viscose silk, made chiefly from sulfite pulp cellulose, constitutes the great bulk of the rayon production today. It is now often combined with natural fibers, particularly wool and cotton, in drapery and upholstery fabrics which afford the luster of rayon plus the strength of wool or cotton.
Flax.—This plant has been cultivated since the stone age, and was regarded as the most important plant of commerce until near the end of the eighteenth century, when it was superseded by cotton. Flax fiber yields linen; also from it is obtained the tow used as a stuffer in upholstering.