Simulation of drawing process based on fiber arrangement in the sliver with straightness and separation degree

Abstract

Sliver irregularity, straightness and separation degree of fibers are three crucial factors in sliver quality. Considering the straightness and separation degree, the drafting model based on the fiber arrangement in the sliver was applied to simulate the drawing process. First, the fiber arrangement in the carding sliver was developed. Then, the drafting process was divided into the low-velocity stage, straightening stage and high-velocity stage to carry out the redistribution of the fiber arrangement so that the sliver quality after drafting can be recalculated from the new fiber arrangement after the drafting procedure. Combining the doubling procedure, the simulated sliver quality of each drawing process was demonstrated to be close to the actual values, taking the straightness and separation degree into consideration. The relative errors between the simulated straightness and percentage of separated fibers and the tested one were all less than 10%. The prediction accuracy of sliver irregularity was raised by about 40%. In addition, the simulated results strongly confirmed the theory that the drawing process has an influence on straightening the hooked fibers, separating the fiber in the assembly and improving the sliver evenness, which cannot be reflected in previous models.

Study of sliver irregularity caused by fiber acceleration motion during the drafting process

“…As an indispensable procedure during the yarn manufacturing process, the drafting process has an appreciable effect on sliver unevenness. [1][2][3][4][5][6] Currently, considerable efforts had been committed to study the influence of the drafting process on sliver irregularity. Balasubramanian and Bhatnagar, 7 Graham and Bragg, 8 Siddiqui et al 9 and Qian and Yu 10 studied the effect of the drafting parameters on the drafting efficiency by analyzing the influence of the drafting force experimentally.…”

“…4,[23][24][25][26] Furthermore, the simulation of the roller drafting process has been carried out based on the model of fiber arrangement in the sliver. 2,3,[27][28][29] Nevertheless, in these models, the fiber in the input sliver before the drafting simulation was regarded to be randomly arranged and the additional irregularity caused by the fore-spinning process was not considered. In the carding sliver, the sliver irregularity calculated from the idealized random fiber arrangement is regarded as the theoretical irregularity, which is far lower than the actual sliver irregularity.…”

“…As an indispensable procedure during the yarn manufacturing process, the drafting process has an appreciable effect on sliver unevenness. 1–6 Currently, considerable efforts had been committed to study the influence of the drafting process on sliver irregularity. Balasubramanian and Bhatnagar, 7 Graham and Bragg, 8 Siddiqui et al.…”