The Effects of Fiber Properties and Preparation on Trash Removal and Properties of Open-End Cotton Yarns

Cotton yarns of 36.9 Tex were spun at optimum twist levels on a Suessen Open-End Spin-tester at opening roller speeds of 5500 rpm, 7000 rpm, and 8500 rpm, and with waste-gap openings of 2.0 mm, 4.0 mm, and 5.5 mm from short and medium length cottons prepared with high and low gin cleaning. The spinning was performed at a constant rotor speed of 45,000 rpm and a static pressure in the spinning chamber equivalent to 7.9 × 10⁻⁵ Pa. Statistical analyses were performed on the data collected from physical tests performed on the yarn and on the amounts of trash extracted into the collection box and deposited in the rotor. These data are discussed along with a study of the nature of trash extracted into the collection box and deposited in the rotor. The results indicate that cotton fiber length was the most significant factor affecting yarn physical properties; yarns spun from short-length fibers were found to have better physical properties, less trash extracted into the collection box and deposited in the rotor, and fewer breakages than yarns spun from medium-length cottons. The degree of gin cleaning significantly affected only neps. More trash was extracted into the collection box and deposited in the rotor from cottons with a higher nonlint content after gin cleaning. Opening roller speed significantly affected single-end strength and thin places. As the opening roller speed increased, single-end strength increased, thin places decreased, the amount of trash extracted into the collection box decreased, and the amount of trash deposited into the rotor increased. The degree of waste-gap opening significantly affected single-end strength. At lower waste-gap openings, more trash was extracted into the collection box, and no significant effect on the amount of trash deposited in the rotor was found. The nature of trash extracted into the collection box was observed to be different from the trash deposited in the rotor.