Spectral Analysis of the Yarn-pullout Force from Plain-weave Fabric

Thread interaction at the warp and weft crossing points of a tensioned fabric is an important aspect of the mechanical properties of the fabric. In this paper, a new approach to measuring changes in thread interaction at the crossing points due to fabric structure and yarn irregularity is discussed. This has been achieved by analyzing thread-pullout behavior from a plain-woven cotton fabric by using an autospectral-density function. It is demonstrated that the nature of the stick-slip motion of the dynamic frictional force of a pulled-out thread is periodic and depends on the fabric construction (warp and weft spacing). The thread-pullout test was also used (on the warp threads only) to investigate the effect of weft-yarn irregularity on the thread-pullout characteristics. It was observed that there is high correlation between warp-pullout force (static and dynamic), the intensity of thread interaction at the crossing points, the strength of fabric in the warp direction, and the weft-yarn irregularity. This new method is important for a quantitative study of the intensity-generating mechanism of thread interactions within the fabric.