Dual-feed rotor spinning of cotton fiber: trash separation and yarn properties

Abstract

In all industrial rotor spinning machines, opening of the fibers is performed by an opening roller, in which sliver is fed from a single point. Increasing number of feed rollers from one to two may improve fiber opening and trash ejection by two-step loading in opening zone of the opening roller. This may improve fiber orientation and blending in the produced yarn and yarn properties. In earlier two sliver feed laboratory systems (dual-feed), it was not possible to work with cotton fiber, because the trash removal zone was used for feeding a second sliver. The aim of this study was to design a system that can take advantage of dual-feed and also extract the trash. The experimental rig was a modified RU04 rotor spinning unit of Rieter in which two separate sliver feed systems were utilized. Raw material used and yarn count were cotton and 29 tex, respectively. Extracted trash and yarn properties produced with dual-feed system were compared with that of the original unit. Yarn properties tested were tenacity, extension, work of rupture, mass irregularity and imperfections, hairiness, and abrasion resistance. Test results were analyzed by ANOVA for any difference between the means and Duncan for ranking. Tenacity, strain at peak, work of rupture, and yarn abrasion of the dual-feed yarn increased, and their mass irregularity and imperfections decreased in comparison to that of the conventional yarn. According to the test results, it was concluded that, increasing number of feed rollers on the opening roller from one to two has improved the yarn properties and trash separation of cotton fiber is possible and comparable to the original single feed.