Reducing Yarn Hairiness Research Articles

Airflow simulation in nozzle for hairiness reduction of ring spun yarns. Part II: Influence of nozzle parameters

In this present work we report the influence of nozzle parameters viz., axial angle and diameter of the nozzle in reducing yarn hairiness during NozzleRing spinning. Three nozzles having varying nozzle axial angles of 40°, 45°, and 50° and a constant nozzle diameter of 2.2 mm, and another nozzle having axial angle of 40° with a nozzle diameter of 2.6 mm were placed at a fixed distance of 10 cm below the front roller nip at ring frame for reducing yarn hairiness. Thirty tex carded cotton yarns were produced with and without nozzles. A CFD (computational fluid dynamics) modeling of airflow inside the nozzle indicates that a nozzle axial angle of 45° and 2.2 mm diameter gives best results in terms of reduction of S3 values. Swirling intensity plays a major role in reduction of yarn hairiness. The change of nozzle diameter plays a lesser role in reducing the S3 values. The difference in yarn diameter and bending rigidity values of NozzleRing yarns and ring yarns spun without nozzle are not statistically significant. Fabrics made from NozzleRing yarns show lesser pilling tendency as compared to those produced from yarns spun without nozzles.

Numerical and Experimental Study on Reducing Yarn Hairiness with the JetRing and JetWind

JetRing and JetWind techniques, which use air-jet nozzles to reduce yarn hairiness, are the latest innovations in spinning and winding of staple yarns. The reduction of yarn hairiness is investigated in this paper both numerically and experimentally. A two-phase air/fiber flow model is developed to simulate the wrapping of a protruding surface hair in the nozzle. The effects of nozzle pressure and jet orifice angle on yarn hairiness are studied by both theoretical predictions and experiments. The results show the consistency of the numerical and experimental study.

Reducing Yarn Hairiness with a Modified Yam Path in Worsted Ring Spinning

The spinning geometry of a ring frame plays an important role, and the twist triangle is the critical region in ring spinning. Changes in the spinning geometry may affect yarn properties. This paper examines the idea of ring spinning with a "diagonal" yarn path, and the effect of such a path on yam properties, particularly hairiness. Both "left diagonal" and "right diagonal" yam arrangements are tried on a 24-spindle Cognetex FLC worsted ring frame. The hairiness results obtained from the Zweigle hairiness meter show that the right diagonal yam path produces yams of lower hairiness than the conventional ring spun yarn in almost all the hair length groups. Yam evenness and tenacity are not as sensitive to the change in yarn path. The mean spindle speed at break is also tested, and there is some deterioration in spinning efficiency with the right diagonal yarn path, particularly at higher spinning speeds. Results from this study may help explain variations in yarns spun on poorly aligned ring frames.

Effect of an Air-Suction Nozzle on Yarn Hairiness and Quality

Various types and parameters of nozzles in the conventional ring spinning machine diversely impact yarn hairiness, which inevitably occurs during spinning. This research attempts to reduce yarn hairiness by designing an air-suction nozzles as alternatives to the commonly used air-jet nozzle, and attaching them to a conventional spinning machine. To examine the effect of various nozzle parameters on yam hairiness and quality, air-suction nozzles with different hole angles and arrangements are designed and employed. The number of hairs longer than or equal to 3 mm is reduced by more than 50% when yams are spun through these specifically designed air-suction nozzles. Other yarn quality measures such as strength, elongation, and appearance also improve with these nozzles, without sacrificing yarn evenness.

Reducing Yarn Hairiness with an Air-Jet Attachment During Winding

The winding process tends to promote yarn hairiness, a detrimental effect that can be significantly reduced by adding a properly arranged air-jet nozzle. This paper examines the mechanisms of hairiness reduction with an air jet during winding. The results indicate that the direction of the majority of protruding fibers and that of the air vortex play an important role. They also suggest that yarn hairiness can be best reduced if the gyrating air current lowers the twist level before the yam enters the jet, and if the air flow spirals along the yarn in a general direction opposite that of the yarn traverse to suppress the majority of protruding fiber ends. Wrapping of protruding fiber ends around the yarn and removal of “wild fibers” by the swirling air current are believed to be responsible for the reduction in yarn hairiness, and tucking of fiber ends into the yarn structure may also occur under certain conditions.

Studies of JetRing Spinning Part I: Reducing Yarn Hairiness with the JetRing

This paper introduces the concept of JetRing spinning, a new spinning technique that incorporates features of both ring and air-jet spinning systems. In JetRing spinning, a single air jet is used below the yarn-forming zone of a conventional ring spinning system; this jet acts in a way similar to the first jet in air-jet spinning. The swirling air currents in the jet wind the protruding fibers around the yarn body, thus reducing yarn hairiness. The air pressure applied to the jet in this study is 0.5 bar, which is much lower than the air pressure used in air-jet spinning. To evaluate the performance of JetRing spinning, ring spun and JetRing spun worsted yarns of 56 tex are tested for hairiness, tensile properties, and yarn evenness. The hairiness results from the Zweigle hairiness meter show that the JetRing spun yarn has much lower numbers of hairs than the ring spun yarn in almost all the hair length groups. The total number of hairs exceeding 3 mm ( i.e., the S3 value) for the JetRing spun yarn is nearly 40% less than that of the ring spun yarn, while both yarn types show little difference in evenness and tensile properties.