Abstract
Recently, the twistless yarns and their fabrics have been developed. In previous paper, it was shown that the rupture forces of the twistless yarn fabrics were as same as those of the conventional twist yarn fabrics. The considerations were based upon the compressive forces working at the intersecting points of the yarns in the fabrics and inter-fiber frictional forces which increase with tension.
In this paper, the initial extensional properties of the twistless yarn fabrics (T0F) and the twist yarn fabrics (T2.6F) are comparatively discussed, concerning the changes of yarn cross-section shapes and sizes (Fig. 8), yarn packing factors (Fig. 9) and yarn crimp angles (Fig. 10) during extension. The aspects of the fabric crosssections are shown in Fig. 7. The various factors of equation (7) are obtained by above experimental results. (Table 2) Fig. 12, the initial regions of load-elongation curves both twistless and twist yarn fabric, are calculated from the equation (7). The calculated and experimental results are compared in Fig. 13. The difference between the twistless and twist yarn fabrics are remarkably characterized by the aspects of initial regions of loadelongation curves. That seems to depend on the differences of mobility of fibers in both fabrics.
