Numerical analysis and experimental investigation of a multi-principle drafting system in ring spinning

The multi-principle drafting device is investigated to improve the comprehensive properties of ring spun yarns. In this study, the front gathering area on the multi-principle drafting device was mathematically modeled to analyze the effects of inlet width, outlet width and path length of the grooved collector on friction forces. The numerical analysis results demonstrate that the outlet width and path length play important roles in frictional forces, while the variation of the inlet widths has little effect on the friction forces. The experiment results also reveal that for 18.4 tex yarns, different outlet widths of the grooved collector have considerable influence on yarn tenacity and hairiness, whereas they show an insignificant effect on yarn evenness and imperfections. Moreover, the effects of process parameters (different roller gauges and break draft ratios) on the novel drafting device with an optimized grooved collector to spin 18.4 tex yarns were investigated by response surface methodology. The results indicate that although the break draft ratio and front roller gauge create significant effects on yarn unevenness, the back roller gauge has no apparent influence on it. In addition, response surface methodology predicted the minimum yarn unevenness of 10.71% under optimal conditions of 1.2 break draft ratio, 32.5 mm back roller gauge and 17.5 mm front roller gauge, which is very close to the experimental result of 10.57%, reaching an advanced level compared to Uster Statistics 2018 of 5%.