聚丙烯高速纺时筒管上的后收缩

聚丙烯高速纺丝工业化的技术难关是聚丙烯纤维在筒管上的后收缩。本工作在有导丝盘系统高速纺丝机上对后收缩过程进行研究,摸清了后收缩机理及各纺丝工艺对后收缩的影响。后收缩的产生,是熔体细流在固化过程中产生的高弹形变所致。减少或消除后收缩的原则是选择正确的纺丝温度和冷却条件以控制纺程上丝条高弹形变的产生。在一定的张力条件下,需尽可能地提供丝条的松弛时间。导丝盘的超喂是一种有效的松弛办法。

THE POST SHRINKAGE ON THE BOBBIN IN HIGH SPEED SPINNING OF POLYPROPYLENE FIBER

The post shrinkage of PP fiber on the bobbin is the technical barrier for the industrialization of high speed spinning technology. In this paper the post shrinkage process on high speed spinning machine with godets systems has been investigated thus its mechanism and the influence of different spinning techology on the shrinkage are understood. As pest shrinkage is caused by the high elastic deformation which occurred in the solidification of melt jets, the principle to reduce or eliminate the shrinkage is the proper selection of spinning temperature and cooling condition in order to control the formation of high elastic deformation in the spinning process and sufficient relaxation time should be given to the filaments under certain tension, for example, the overfeed at the godets is a effective measure of relaxation.