The Insertion of ‘Twist’ into Yarns by Means of Air-jets. Part I: An Experimental Study of Air-jet Spinning

Abstract

A comparison of the yams spun on three different arrangements of air-Jets shows that the Murata-type twin-Jet arrangement produces well-wrapped, strong yams.For the production of a high level of fasclatlon, it Is necessary that the distance between the front roller nip and the position at which the edge flhres contact the aain strand should he as long aa possible.If the edge fibres contact the strand close to the roller nip, they will either not produce wrapping fibres or at best produce very short wraps.An analysis of the wrapping-fibre formation Indicates that the Hurata principle Is advantageous ln creating long and effective wrapping fibres. Some of the spinning condltions are 1 nvestigated, and the reaults are interpreted In accordance with the above mechanism.

Numerical simulation of tangentially injected turbulent swirling flow in a divergent tube

“…The simulation results show that the higher injector pressure leads to high spinning tension. This is in agreement with the spinning experimental results by Grosberg et al [1] and Punj et al [34]. From the perspective of energy conservation and the results of the simulation, it is not sensible to increase the injector pressure to a very high level.…”

3D numerical simulation of compressible swirling flow induced by means of tangential inlets

“…Several researchers have used spinning experimental methods to study the influence of nozzle pressure [1][2][3] and the results show that it is the most important parameter affecting the mechanical properties of air-jet yarns. Because the radial velocity is very weak, Figure 8 only shows the tangential and axial velocities' profiles along radial direction at different z-axial positions for the different pressure P = 1.5, 2.0, 2.5 and 3.0×10 5 Pa cases.…”

“…Consequently, increased attention is being paid to the prediction of the swirling flow characteristics in the twisting chamber in order to produce a high quality yarn. However, at present, most of the information available in the literature on air-jet spinning is related to the yarn structure [1][2][3], the principle of yarn formation [1,4] and the effects of various parameters on yarn quality [1-3, 5, 6], and these are closely related to the flow characteristics in the nozzle. Only Zeng and Yu [6] and Yu and Zhang [7] used experimental and numerical methods, respectively, to study 2D airflow field in the nozzle.…”

Simulating the motion of a flexible fiber in 3D tangentially injected swirling airflow in a straight pipe—Effects of some parameters

“…Especially, it is used in the textile industry to produce air-jet spun yarns. Different from general particle transportations, in air-jet spinning system, the long flexible fibers are transferred and twisted and wrapped each other under the effects of the swirling decaying airflows, and consequently a high quality yarn can be produced [4]. Therefore, the study on the dynamics of flexible fibers in a swirling flow is of both theoretical and practical importance.…”

“…Our previous studies [23] also showed that the nozzle geometric parameters influence the swirling flow characteristics, and further affect the fiber dynamics and the yarn quality. According to the principle of the yarn formation [4,24] and the swirling flow behaviors, the release position of a fiber will also influence the fiber motion. Based on above, the present work is dedicated to the effects of both the first nozzle geometric parameters and initial position on the flexible fiber motion.…”