Twist structure of friction-spun yarns: Part II — Core-spun DREF-III yarns

Abstract

<span style="font-size:14.0pt;mso-bidi-font-size:12.0pt;font-family:" times="" new="" roman","serif""="" lang="EN-IN">The twist structure of DREF-III friction-spun yarns has been studied by optical method. It is observed that the different layers of sheath fibres exhibit more or less the same average twist as observed in the fibre layers of DREF-II structures. However, under the identical spinning conditions this twist is lower than the twist in DREF-II yarn structures and the use of coarser fibres further reduces it. The twist also shows a decreasing trend with the increase in fibre length from 25 mm to 44 mm followed by a slight increase thereafter. Core fibres, instead of being straight and parallel to the yarn axis as generally expected, are seen to be twisted. Both the core and the sheath fibres twist values have been found to increase with the increase in suction pressure. A decrease in core content increases the core twist while the sheath twist drops after an initial increase.

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