Comparison of DREF-3 Cotton Yarns Produced by Varying Yarn Core Ratios and Feed Rates

This study evaluated yams produced on the DREF-3 friction spinning machine using varying core inlet sliver linear densities and output yam core proportions. A long staple, medium micronaire, Acala cotton was spun into 74, 54, and 45 tex yams at constant spinning drum and outlet speeds. Inlet sliver of 1.77, 2.47, and 3.18 ktex linear densities was supplied to the yam core at rates required to produce yams con taining between 40 and 70% core. To make yams of the same size and core ratio, lighter core sliver had to be supplied at faster inlet speeds or heavier core sliver at slower speeds. Using lighter core sliver at greater inlet speeds improved yam strength and evenness. Among these, coarser yams and those with higher core ratios showed better uniformity. Yarns supplied by lightweight core sliver showed similar elongation; those supplied by heavyweight core sliver showed more variation over the range of core ratios.