Friction field distribution is a critical factor in the drafting process, as it affects the fiber bundle movement in the main draft zone. In this paper, a modified draft device, named the multivariate principle curve draft device, which extends the friction field and condenses fiber bundles, has been employed to produce colored spun yarns. To analyze the effect of the modified draft device in the spinning process, mechanical analysis and finite element simulation were applied. In the mechanical analysis, the curvature surfaces of the grooved compactor exert friction force on the fiber bundles to restrain the peripheral fibers, and the relation between the friction and angles of the contact surfaces was concluded. In the numerical simulation, the result shows that the friction force distribution in the curved drafting channel is extended and enhanced, which leads to the forward distribution of the fiber accelerated points. Meanwhile, 28.1 tex blended colored yarns (cotton/polyester/viscose 30/30/40) and 19.7 tex pure viscose colored yarns were spun by the modified and conventional draft sets on a ring spinning machine. The comparative results imply that the modified device ensures outstanding yarn properties, such as yarn evenness, hairiness and imperfections, although there is some decrease in the yarn strength.

中文翻译：

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一种多元主曲线牵伸装置的力学分析与数值模拟及其纱线性能分析

摩擦场分布是牵伸过程中的一个关键因素，因为它会影响主牵伸区中的纤维束运动。在本文中，一种改进的牵伸装置，命名为多元主曲线牵伸装置，它扩大了摩擦场并凝聚了纤维束，已被用于生产有色细纱。为了分析改进后的牵伸装置在纺纱过程中的作用，应用了力学分析和有限元模拟。在力学分析中，凹槽压实机的曲率表面对纤维束施加摩擦力，以约束外围纤维，并得出摩擦力与接触面角度之间的关系。在数值模拟中，结果表明，弯曲牵伸通道内的摩擦力分布得到延伸和增强，导致纤维加速点向前分布。同时，28.1 tex 混纺色纱（棉/涤纶/粘胶30/30/40）和19.7 tex 纯粘胶色纱在环锭纺纱机上通过改进和常规牵伸装置纺制。比较结果表明，虽然纱线强度有所降低，但改进后的装置可确保出色的纱线性能，例如纱线均匀度、毛羽和疵点。