牵伸区浮游纤维变速点分布的理论研究

纤维头端的变速点不一致是造成牵伸后纱条条干不匀的主要原因。通过对纤维在牵伸区变速的条件做细致的分析,把牵引力大于控制力的条件用概率表达,并在牵伸区内假设快、慢纤维在各个截面上的动态规律,给出了固定长度的浮游纤维变速点的方差表示,再使用分布函数的原理,将浮游纤维在牵伸区变速点的方差表达成压力和摩擦因数的函数。从方差表示上可进一步分析纤维长度分布和牵伸区压力分布对浮游纤维变速点的定量影响。

Theoretical study on the distribution of accelerated points of floating fibers in the drafting zone

The previous research demonstrated that the dispersion of the accelerated points of floating fibers is the main reason of the unevenness of the drafted slivers.This paper theoretically analyzed the condition under which the fiber in the drafting zone is accelerated.The condition of the fiber acceleration is expressed in a probabilistic form regarding the condition that the drafting forces are greater than the control forces.The dynamic law of the fast and slow fibers in any profile in the drafting zone is assumed and for a fiber of given length the variance of the accelerated points is obtained.Therefore the distribution function principle can be used to give the overall variance of the accelerated points.The pressure and friction coefficients are incorporated into the variance.Further analysis can be drawn on the basis of the variance obtained.