The consistency (by mean of evenness) and yarn surface integrity (by mean of the yarn hairiness) are main indices, which influence the appearance of final woven or knitted product. This study focuses on the effect of some m/c and process parameters on the evenness and hairiness properties of 100% viscose vortex spun yarns. Based on the Box and Behnken Design, MVS yarn samples were produced with three levels of yarn delivery speed, nozzle pressure and sliver hank. The technique of regression

more »

... ysis of response surface was used to evaluate the yarn samples on the basis of yarn evenness, yarn hairiness (H), yarn hairiness variation (sH), thick places, thin places and neps per km. The results indicate that yarn uniformity initially increases and then decreases with the increase in the sliver hank. At low yarn delivery speed, yarn evenness decreases with the increase of nozzle pressure, but at high nozzle pressure, yarn evenness improves with the increase of yarn delivery speed. Yarn hairiness increases linearly with an increase in yarn delivery speed, and it decreases with an increase in nozzle pressure. Sliver hank influences the number of thick places remarkably and with the increase of sliver hank, number of thick places initially decreases and then increases.