细纱机后区压力棒牵伸的效果及牵伸倍数的优化

Effect of pressure bar in back drafting zone of SKF drafting system on spun yarn quality and optimizing drafting ratio

为提高成纱质量,在细纱机的后牵伸区加装压力棒后细纱机的后区牵伸倍数需要改变。当后区牵伸倍数过小时,粗纱在后区不能有效牵伸,使成纱的粗节增多。如果后区牵伸过大,会引起牵伸波使成纱质量恶化。测试、分析了细纱机后区加装压力棒后纺纱效果及后区牵伸倍数对成纱条干CV值、粗细节及棉结等质量指标的影响。结果表明,纺制捻系数为109、定重为0.545 g/m粗纱的最佳纺纱条件是后区牵伸倍数为1.35,中后罗拉的握持距为51 mm,。

For improving the quality of spun yarn, the back draft ratios of SKF drafting system have to be changed when two pressure bars are fitted additively. When the back draft ratio is too low, the twisted roving cannot be sufficiently draft in the back drafting zone, resulting in thick places in the spun yarn. When the back draft ratio is too great, a drafting wave in the drafting roving is caused, and the quality of spun yarn is influenced. The effect of the back draft ratios in SKF drafting system on CV value, thin places, thick places, neps, strength and elongation of spun yarn were analyzed. The results of our investigations reveal that when the back draft ratio is 1.35 with roller setting of 51 mm, the optimum spinning conditions are obtained for the roving of 0. 545 g/m and 109 twist multipliers.