聚丙烯高速纺丝工艺的研究——卷绕丝超分子结构与后加工性能的工艺控制

利用X射线衍射、DSC、双折射、密度梯度等方法探讨了在3km/min高纺速下,纺丝温度对丙纶POY的超分子结构与后加工性能的影响,对冷却条件的影响也进行了讨论。指出在280℃以下范围提高纺丝温度可以降低聚丙烯高速纺程上的流变张力,使卷绕丝的结晶度降低,结晶成分中次晶含量增加,非晶区取向度提高。采用缓慢冷却有和于提高POY的非晶区预取向。采用MI=35的聚丙烯树脂,在纺丝温度270℃和缓冷条件下可得具有优良后加工性能的丙纶POY,在414m/min速度下经加弹所得DTY的强度为41.1cN/t(?)x,伸长为34.1%,卷曲率为20%,卷曲稳定性为92%。

RESEARCHES ON HIGH SPEED SPINNING PROCESS OF PP FIBER——CONTROL OF SUPERMOLECULAR STRUCTURE AND AFTER-PROCESSING PROPERTY OF PP POY

The effect of spinning temperature on supermolecular structure and after-processing property of PP POY at the high speed of 3000m/min was studied with the aid of X-ray diffraction, DSC, birefringence and density gradient etc.. The effect of quenching condition was also discussed. The increase of spinning temperature under 280℃ could make the theologic tension on spinning line and the crystallinity of the POY decrease and the hypocrystalline content of crystalline composition and the amorphous orientation of macromolecules increaes. Slow quenching was favourable of increasing the pre-orientation of amorp-hous region. Using the polypropylene resin with MI=35, the PP POY with excellent afterprocessing property could be produced under slow quenching conditions at spinning temperature of 270℃. The PP DTY with tenacity 41.1 cN/tex, elongation 34.1%, crimp ratio 20%,crimp rigidity 92% was obtained in the processing speed of 414m/min.