The Zinser Sirospun system facilitates processing of most natural and manmade fibers and blends in the long and short staple ranges. The sirospun facility also allows manufacturers to influence the structure and properties of the spun yarn, and, therefore, to react more effectively to various market requirements and increases in production. All Zinser ring spinning machines and many machines manufactured by other companie can be retrofitted with a Sirospun facility. When used in place of single yarns, the Sirospun plied yarn system dramatically improves yarn quality. Sirospun can be substituted for conventionally plied yarns in certain applications. It eliminates such process stages as dubling and twisting and increases production of ring spinning machines by as much as 100 percent. The sirospun system produces fine plied yarns for high quality woven apparel fabrics, medium count plied yarns for suiting and costume fabrics, coarser grade yarns for home furnishing fabrics and special applications, plied yarns in the fine count range for light shirts and blouses, and medium to coarse plied yarns for industrial fabrics, industrial apparel, table lines, and fancy yarns.