空气捻接器纤维加捻机理的仿真与实验研究

Numerical and Experimental Study on the Principle of Fibers' Splice in the Pneumatic Splicer

纤维捻接是纺织络筒工序中的关键技术之一。为研究其捻接机理,需要结合仿真与实验技术,通过流体力学模型对空气捻接腔体内旋转气体的流动进行仿真计算,并分析纤维束的运动特征。对原纱、解捻纱和加捻纱的特征部位分别进行了结构观察,使用捻距L和直径d分别表征纱线的捻接效果和外观,结合仿真计算结果,对纱线捻接机理进行了分析。研究结论如下:(1)气流在加捻腔中发展成涡流,涡流促使纱线绕加捻腔轴中心旋转缠绕,形成节点。(2)捻距L值可以作为衡量纱线捻接效果的一个重要指标,其值越接近于原纱L值,纱线捻接效果越好;直径d值能够用于判断纱线捻接区域,若某部位直径d值大于原纱d值,则该部位是节点部位。

In the present study, both numerical and experimental techniques were employed to investigate the principle of splicing fibers in pneumatic twisting mechanism. Based on the simulation of swirling airflow in splicing chamber through CFD mode[, the research analyzes the characteristics of fiber bundles＇ movement. The experiment that feature parts of original yarn, untwisting yarn and twisting yarn are observed, measures twist pitch L and diameter d to specify the effect and appearance of twisting respectively. By combining the simulation results, it has been demonstrated that （1） the external fibers of splicing chamber continually strike on the wall and untwist caused by strong airflow from nozzles. Meanwhile, the swirling airflow flows into the cover holder in which the fibers twist and produce a thick knot, （2） the twist pitch L can be used as a measurement of splicing fibers, the closer to the original yarn of it, the better the results, and it also can directly judge the different twisting area by diameter d, the one whose diameter is greater than original yarn＇s is thick knot, and the biggest diameter is the center knot.