Tensile Drawing of Rotor Spun Yarn: Part I: Consideration of Processing Variables and Property Changes in Generated Yams

Rotor spun yarn, despite its growing popularity, suffers the disadvantages of lower tenacity, limited count range, and harsh handle of the resulting fabrics. Therefore, this work probes the possibility of eliminating these drawbacks by using tensile drawing. The yams are produced with different specifications from the same fibers. The results are encouraging, since contrary to predictions, staple yams treated this way do perform properly. Tensile drawing especially improves rotor spun yarn quality in terms of structural/mechanical evenness and processability. Other features include increased pack ing density, reduced yarn diameter, enhanced mechanical rigidity, and even the potential for larger tenacity. The influence of processing variables on yarn properties is also revealed by examining the contribution of the number of yarn loops mounted on the feed roller and rewinding to drawing and the resulting products. The number of yarn loops wound on the feed roller is significant in terms of drawing tension. Optimum drawing can be obtained without rewinding in terms of better yarn properties and economics, though rewinding can effectively eliminate fiber breakage. Moreover, the truely critical factor in the drawing extent should be drawing tension rather than the so-called drawing ratio.