Investigation and evaluation on fine Upland cotton blend yarns made by the modified ring spinning system

Abstract

A modified ring spinning technology has been successfully applied to the production of yarns with reduced twist level and improved performance. Various US cottons and Chinese cottons have been covered in previous studies. In this paper, three combed rovings with different blending ratios of Upland and Extra Long cottons were adopted in a systematic investigation and evaluation on a fine modified ring yarn produced on a new modified spinning system that was developed to reduce the imperfections of fine yarns. The potentially important spinning parameters were proposed and their individual and interaction effects of spinning system parameters on the properties of fine modified ring yarn were quantitatively examined using the response surface methodology. Then with the optimum parameters, physical properties of the yarns and their knitted fabrics produced from three rovings were evaluated by comparing them with the conventional ones. Experimental results showed that yarns produced in the new modified spinning system had reduced imperfections; at low twist levels, fine modified yarns and resultant fabrics also showed improved performance. Moreover, properties of fiber materials and roving quality influenced the properties of modified yarns and knitted fabrics.

Siro false twist spun yarn structure and the knitted fabric performance

“…Ying et al. 31 found that the running speed and the spatial position of the false twisters, as well as their contact angle with the yarn whiskers, affected the quality of ring spun yarns significantly. In this work, the distance between the two false twisters was fixed at 6 mm, and the front roller speed was set at 20.5 m/min.…”

“…Different from the conventional siro spinning, the siro false twist spinning system was constructed by additionally installing double tangential belts working as yarn guides and false twisters between the front roller and the yarn guide of the FA506 spinning frame (Jingwei Textile Machinery Co. Ltd.), which is schematized in Figure 1. Ying et al 31 found that the running speed and the spatial position of the false twisters, as well as their contact angle with the yarn whiskers, affected the quality of ring spun yarns significantly. In this work, the distance between the two false twisters was fixed at 6 mm, and the front roller speed was set at 20.5 m/min.…”

A critical review on recent developments and solutions in the high-speed ring spinning process

“…This is why a false twisting device was added to impart false twist in the spinning triangle zone, that is, in the weakest point of the yarn path located immediately after the front rollers of the drafting system, to increase process stability and yarn quality. [71][72][73][74][75][76][77][78][79][80][81][82][83] Yilmaz has studied the characteristic properties of the yarn by integrating a false twisting device comprised of air nozzles between the drafting system and yarn guide to reduce the yarn hairiness up to an angular spindle speed of 10,000 rpm in the conventional ring spinning process (Figure 20). 71 The objective of integrating the pre-twisting device was to bind the projected fibers onto the yarn body by the swirling airflow in the nozzle.…”

“…A further false twisting method deals with the Nu-Torque technology based on one or two separate false twisting devices positioned between the yarn guide and delivery rollers of the drafting system in the conventional ring spinning process in order to reduce the residual torque in the yarn. [76][77][78][79][80][81][82][83][84] As illustrated in Figure 22, the drafted roving passes through the two twisting elements, that is, the false twisting device and the ring/ traveler system rotating in the same direction, to impart twist in the yarn. The preliminary single yarn is generated through the rotation of the false twister, which is untwisted just after leaving the false twister and, finally, the real twist is imparted in the yarn through the ring/traveler twisting element.…”

“…The preliminary single yarn is generated through the rotation of the false twister, which is untwisted just after leaving the false twister and, finally, the real twist is imparted in the yarn through the ring/traveler twisting element. 79 The spun yarn (6-100 Ne) possesses 10-40% reduced twist, but the same or higher yarn strength, lower yarn hairiness and better yarn evenness compared to the ring spun yarn. 78,79 Moreover, the low torque ring spun yarn is compacter than that of conventional ring spun yarn.…”