Influence of Rotor Speed, Rotor Diameter, and Carding Conditions on Yarn Quality in Open-End Spinning

Results of studies are presented examining the effect of rotor speed, rotor diameter and tandem carding on properties of open-end (OE) yams. Most of the yam properties excepting strength show a significant deterioration with increase of rotor speed, in case of strength, no consistent trend was observed. Yarn elongation drops steeply, while Uster nep count increases markedly with increase of rotor speed or rotor di ameter, the higher centrifugal force in the rotor zone being responsible for the change in yarn properties. Evidence shows that the steep increase in neps at higher rotor speed and diameter is because of imperfections caused by wrapper fibers. Tandem carding does not confer any significant improvements on OE yarn quality in normal mixing, while marginal benefits occur in waste mixing. The benefits of tandem carding in OE spinning may be more in terms of reducing the microdust accumulation in the rotor. With waste mixings, the strength loss from OE spinning is much reduced and the reductions in yarn imperfections are very pronounced, indicating that OE spinning offers a potential outlet for better waste material use. Though inferior in strength, OE yarns exhibit a better strength uniformity than ring spun yams, which may contribute to satisfactory performance of this material in subsequent stages.