Device for Producing Staple-Core / Cotton-Wrap Ring Spun Yarns

This paper describes a device that effectively produces a unique staple-core/cotton- wrap composite yarn on a slightly modified ring spinning frame. Such a yam consists of a man-made staple fiber core that is wrapped with cotton fibers. The core provides high strength and other functional characteristics, while the wrap provides the tradi tional look, feel, and comfort of cotton. Polyester staple-core/cotton-wrap yams of coarse, medium, and medium-fine counts have been successfully produced by this new device. The yarns have been knitted on a small sample knitter without difficulty or special treatment, indicating that they can be woven without problems. A simple method of estimating the so-called "cotton sheath attachment draft" for a particular size and twist yarn is described. A computer model shows the estimated sheath at tachment drafts for 37-tex (Ne 16) polyester staple-core/cotton-wrap composite yarns spun with different twist multiples. Typical production parameters, quality test data. and magnified photographs of some staple-core yarns are provided. The test data indicate that a 38% high tenacity polyester staple-core/62% cotton-wrap yam made with the new device is stronger than an equivalent ring frame-blended (simulating intimately blended) yarn or a 100% cotton yam. The cotton wrap contributes to the overall yarn strength, although not in proportion to the percentage of cotton fibers in the yarn. Important uses of cotton-covered, polyester staple-core yarns are easy care apparel fabrics, high tenacity sewing threads, and strong pill resistant fabrics with the comfort and look of cotton.