Thesis Details

Thesis Title: Determining the practical spinning limits of open-end carded and combed yarns produced from pima, upland, and California cottons at various rotor speeds
Thesis Author: Michael Tutterow
Abstract: Yarn manufacturers continuously look for new ways to produce quality goods at a lower price. One way to accomplish this would be to replace ring yarns with open-end yarns. One drawback, however, is the count range limitations of open-end spinning. In the early days of open-end spinning Ne 14 count was considered the spinning limit for open-end yarns. Over the years this limit has been extended almost linearly. At any given time it is helpful to understand the limitations within the open-end process, especially when there are machine or component innovations. This thesis was designed to define practical spinning limits with the newest generation of openend spinning machine with regard to cotton type, carding versus combing., and the influence of rotor speeds. To meet the requirements of this study, three cotton varieties were carded and then combed at two noil levels. Then the carded and combed conditions were spun at three different rotor speeds. It was determined that cotton type, combing, rotor speed, and the three associated interactions significantly influenced spinning limits. When spinning was completed each yarn variable was knitted to evaluate fabric appearance. Fabric uniformity was superior for the Pima cottons, evidently because the Pima yarns had the best average yarn appearance grade and the lowest uster CV%. Based on the parameters studied in this research, several ways exist to improve spinning limits. Combing, even at 8 percent noil, was found to improve spinning limits by reducing trash content and short fiber content. Moreover, there were natural differences between cotton varieties because of intrinsic fiber properties, indicating that fiber selection is critical.