Effects of lattice apron density on yarn qualities in Four-line compact spinning system

Abstract

In the paper, using finite element method (FEM), the effects of lattice apron density on yarn qualities in Four-line compact spinning system were studied by analyzing the numerical simulations of the airflow velocity. Firstly, three different kinds of yarns, 18.2tex (32 S ), 9.7tex (60 S ), and 5.8tex (100 S ), were spun on FA507B spinning frame equipped with lattice aprons of mesh size 150, 120, and 100, respectively. The hairiness, breaking strength, and evenness of spun yarns were tested and comparatively analyzed. Secondly, using FEM, the numerical simulations of the airflow velocity in the condensing zone were presented. The finite element model of condensing zone was constructed according to the physical parameters of the practical system. Then, the simulation of airflow velocities on five straight lines located in the front, middle, and back of condensing zone were given. It is shown that, in the whole condensing zone, for the lattice apron with mesh size 100, the direct transverse condensing force is high, but the assisted condensing force is low and disorder, which is not beneficial for yarn qualities. Compared to the lattice apron with mesh size 150, the usage of lattice apron with mesh size 120 may be beneficial for the high-count yarn condensing or the yarn condensing under the relatively lower negative pressures. Furthermore, taking the 9.7tex as an example, the trajectory of yarn movement in the condensing zone was given using high-speed camera system OLYMPUS i-speed3. Corresponding airflow velocities along the yarn movement path were presented.

Numerical Simulation of the Condensing Effect of Different Suction Slots on Fiber Strands in a Compact Siro Spinning Machine with Lattice Apron

“…Zou et al [7] proposed a dynamic model of the infinitesimal element of the flexible fiber, which describes the flexible fiber trajectory in the condensing zone of compact spinning with a lattice apron. This paper mainly studies the compaction effect of fiber strands in the condensing zone.…”

“…Current research on the spinning mechanism of compact siro spun technology, compact siro spun yarn structure, and the relationship between spinning process and yarn quality is not enough for optimizing the compact system and for improving compact technology. Liu et al [7] studied the effects of lattice apron density on the yarn quality in a four-line compact spinning system by analyzing the numerical simulations of the airflow velocity; Akankwasa et al [8] evaluated the dual-feed rotor spinning unit based on airflow dynamics and blended yarn properties; Jungbecker et al [9] developed a kinematic model for yarn movement in turbulent airflows. These provide new research ideas and methods for the study of compact siro spun yarn.…”

“…Machine drawing of compact siro equipment[7].AUTEX Research Journal, Vol. 20, No 1, March 2020 DOI: 10.1515/aut-2018-0058 © AUTEX http://www.autexrj.com/ (a) parallel shaped slots (b) oblique parallel shaped slots (c) V-shaped slots Figure Shape and dimension of the suction slot [6].…”

Effect of Lattice Apron Age on the Quality of Compact Ring-Spun Yarns

“…Nowadays, lattice apron is the most popular component for compact spinning [48] which should be designed appropriately. It is circular in size with around 3000 holes per square cm, which doesn't allow the fibers to be sucked in but micro-dust can be sucked out from the yarn.…”

Mechanical modeling of an arc-shaped suction slot for compact spinning and analysis of additional twists

“…It has the advantages of structural simplicity and convenience in modification, but also faces complex equipment maintenance and other issues. Research on compact spinning is mainly focused on mechanism, 1 structure and performance of the yarn, 2–5 material and production of lattice apron, 6 and analysis of airflow field. 7–10 Many detailed studies have been published on the structure and performance of compact-spun yarns.…”