并条机后区牵伸倍数的模拟设计

Simulating design for draft ratio of back drafting zone on drawing frame

为快速确定不同条子并条工艺的后区牵伸倍数,采用拉伸的方法模拟并条机后牵伸区的牵伸,进行后区牵伸倍数的设计,并以棉、涤纶和粘胶为原料进行实验。结果表明,拉伸曲线和牵伸力-牵伸倍数曲线有很大的相似性。由拉伸曲线中最大拉伸力所对应的伸长转化而来的牵伸倍数和并条牵伸力测试的实验数据拟合的三次方程得出的最大牵伸力所对应的牵伸倍数非常接近,此牵伸倍数下牵伸力不匀和并条牵伸后输出须条的条干不匀都小,故根据拉伸曲线的结果来设计并条机的后区牵伸倍数是可行的,为并条机后区牵伸倍数的快速离线设计提供了参考。

In order to determine the draft ratio of back drafting zone of different slivers during drawing process efficiently,the tensile method was used to simulate drafting of the back drafting zone on a drawing frame.Cotton,polyester and rayon slivers were used in the experiments,respectively.The results show that tensile curves and drafting force-drawing multiple curves are very similar.The draft ratio translated from the critical elongation in tensile stress-strain curve is very close to the one calculated from the fitting cubic equation of the experimental data in the drafting force test when the maximum drafting force occurs,and the coefficient of the variation of the drafting force and output slivers unevenness are both low at the critical draft ratio.The draft ratio of back drafting zone,therefore,can be designed according to the tensile curves.The result provides a certain reference for the rapid offline design on the draft ratio of the back drafting zone on drawing frame.