Balanced & Unbalanced Yarns Direction of twist Single, Ply and Cord Yarns Single Yarn Ply Yarn Cord Yarn A single yarn is made A ply yarn is made by Cord yarns are directly from fibers. second twisting operation composed of two or more which combines two or more ply yarns combined for singles. Each part of the yarn is simple cord yarns, the called a ply. The twist is singles used to make the inserted by a machine called ply yarns and the ply yarns twister. The ply yarn is also used to make the cord are known as folded yarn. simple yarns.

c. Processing of Silk: In order to produce unpierced cocoon the chrysalis is killed by heat in dry air, more rarely by hot water or steam. The cocoons are weighed; the female moths being heavier, can thus be selected and allowed to escape. The moths live only a few days, during which they mate and lay eggs. It is estimated that nearly 3000 cocoons are required to make a yard of silk fabric. Silkworms are subject to many diseases. The most important of these is pebrine. The worms are damaged by changes in room temperature and by moisture in their food. These factors influence the quality of silk produced. Wild silk is that produced from other types of moths, which have not lent themselves to domestication. These cocoons must be sought in the trees and many of them have already been pierced when found. Wild silk is less uniform but is coarser and somewhat stronger than the cultivated variety. The most common wild silk is that from the tussah or tussar silkworm of Asia. This worm feeds on mulberry, oak and other trees. The term is generally applied to all wild silks, but strictly speaking tussah is an Indian silkworm.