Study on fibre migration at different yarn layers

Abstract

The magnitude of deviations (root mean square deviation) from the mean radial position of the fibre has been studied in various yarns by using tracer fibre technique. Three sets of yarns with tracer fibre have been prepared, considering different break drafts, yarn twists and traveller weights. The effect of yarn tension and twist due to position of ring rail (balloon height) and yarn package diameter has been nullified by taking samples from the various cops at the same height and yarn package diameter. The results of root mean square deviation of tracer fibres have been categorized with respect to the span length and their mean radial position and then analysed. It is observed that the increase in traveller weight causes an appreciable decrease in root mean square deviation and has no significant effect on the mean radial position of the fibre. Similarly, the increase in yarn twist causes an increase in root mean square deviation and decrease in mean radial position. The increase in break draft enhances the root mean square deviation initially and then causes it to decrease while the mean radial position increases steadily with the increase in break draft. Migration study has also been carried out in the yarn present at the bare of the cop and surface of the cop. Root mean square deviation of yarn measured at bare of the cop is less as compared to that of the yarn present at the surface of cop.