FIBER ASSEMBLY IN FRICTION SPINNING

Both classic and novel research methods were used to study a number of questions concerning the mechanisms involved with fiber assembly in friction open-end spinning of cotton yarns. The equipment used was a much-modified DREF-3 friction-spinning unit with replaced suction rolls and equipped with a comber-roll assembly from a Platt 881 rotor-spinning unit. Reynolds-number simulation in a water medium provided a means of determining the source of flow instabilities in the vicinity of the nip. Considerable energy losses were found as a result of flow inefficiencies in the inner cylinders, and methods of improving the cylinder design were suggested. The use of short-duration flash techniques provided a means of determining fiber orientation prior to accumulation and assembly on the yarn tail. These techniques made it possible to photograph the yarn tail forming as well as the gradual tightening of the structure upstream of the original yarn-forming position. Determination of mechanisms of capture of the fiber by the yarn tail were also a result of the high-speed photographs. The theory of fiber escape from the yarn tail during the initial introduction was hypothesized and viewed as a complement to the various capture mechanisms.