Definition of Ply Yarn
Single yarns are used in the majority of fabrics for normal textile and clothing applications, but in order to obtain special yarn features, particularly high strength and modulus for technical and industrial applications, ply yarns are often needed.
A folded or ply yarn is produced by twisting two or more single yarns together in one operation, and a cabled yarn is formed by twisting together two or more folded yarns or a combination of folded and single yarns.
The twisting together of several single yarns increases the tenacity of the yarn by improving the binding-in of the fibers on the outer layers of the component single yarns. Ply yarns are also more regular, smoother and more hard wearing. The direction of twisting is designated as S or Z, just as in single yarns.
Normally the folding twist is in the opposite direction to that of the single yarns.
Constructions of Ply Yarn in Image