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

Abstract

In this study, an arc-shaped suction slot was designed for a pneumatic compact spinning system with a lattice apron. A model was built via mechanical analysis of a fibrous strand in an arc-shaped suction slot to calculate additional twists inserted during condensing. The equations can be solved by using the Runge–Kutta method. The simulation results showed that negative pressure and frictional coefficient of the lattice apron and the fibrous strand have significant effects on additional twists of the strand in an arc-shaped slot. The curvature radius of the arc slot has some influence on the additional twists, while that of the condensing surface has no obvious effect on the additional twists. The radius of the strand may significantly influence the additional twists, but the radius of the strand itself is affected by various other factors. Spinning tests were carried out based on the model design. These results verified the additional twist model of the arc-shaped suction slot.

Study on the model of semi-open-end twist in compact spinning with lattice apron

“…The derivation and calculation of tension T in the linear-shaped suction slot is similar to that in an arc-shaped suction slot, which was presented in our previous work. 1 The linear-shaped suction slot is on the curved surface R. The lattice apron covers the surface that the fiber strand moves upon the apron when spinning. Take a small segment of the fiber strand ds at point O in the suction slot, as shown in Figure 5.…”

“…On this plane, dθ is the central angle corresponding to d s on the plane Y 1 OZ, (unit: rad), therefore, the following can be obtained:

Figure 6.Diagram of arc AC 1 on the plane Y 1 OZ. 1

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“…A clear understanding of the compact spinning mechanism is conducive to produce higher quality yarn. At present, research on compact spinning mainly focuses on the additional twist mechanism, 1,2 the airflow field, [3][4][5] and the structure and performance of the compact spun yarn compared with the conventional spun yarns. [6][7][8][9][10][11] In perforated-lattice negative-pressure type compact spinning, the twist of the compact yarn is about 3-10% higher than that of ring-spun yarn under the same spinning conditions.…”

A Novel Compact Spinning with Lattice Apron Achieved through Airflow Simulations

“…This technique is implemented using negative pressure airflow to condense the fiber bundle for eliminating the spinning triangle and improve the yarn qualities [1][2][3]. Compact spinning with lattice apron is the most widely used pneumatic compact spinning system at present, mainly including three-line compact spinning (TLCS) and fourline compact spinning [4][5][6][7][8]. Nevertheless, the compact spinning systems with lattice apron is considered expensive due to the high energy consumption during the spinning process [1].…”

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

“…A detailed study was conducted by Han et al [45] on simulation and characterization of the flow field in the condensing zone are made by computational fluid dynamics software which mainly includes the distribution rules of static pressure and velocity to explain the theoretical basis for optimum compact siro yarn properties in the practice of production. Fu et al [46] developed a pneumatic compact spinning system with an arc-shaped suction slot with lattice apron to determine additional twists inserted during condensing. Khurshid et al [47] investigated the influence of pneumatic compact spinning system by using Rieter® K-44 compact spinning with coarse, medium and fine linear densities of both ring siro and compact siro spun yarns hence to compare irregularity with respect to mass, IPI, hairiness and tensile properties between two types of siro yarn.…”