超高强低收缩丙纶长丝的制备

PREPARATION OF ULTRA HIGH STRENGTH AND LOW SHRINKAGE POLYPROPYLENE FILAMENT

介绍一种熔纺-湿法纺丝工艺制备超高强低收缩丙纶长丝的方法。这种方法采用冷却水槽对从喷丝板喷出的丝束进行快速冷却,代替现有侧吹风风冷制备超高强低收缩丙纶长丝,从而有效回避丝束在120~130℃之间产生结晶,避免由此产生的结晶对拉伸取向工艺的影响,提高了拉伸取向的一致性,从而提高聚丙烯的取向度来实现强度的提高,控制纤维断裂伸长率。结果显示,慢速拉伸速度(出丝速度)设置100 m/min,选用熔融指数为16 g/10 min的聚丙烯切片干燥温度75℃,螺杆挤出机各区温度控制在220~260℃,挤出机的压力控制在(8. 0±0. 1) MPa,喷丝板孔数120 f,冷却水槽水温控制在12~20℃,喷丝板离水面距离3~10 cm;热辊温度控制在80~135℃,可纺出性能优良的超高强低收缩丙纶长丝,纤维产品的规格为1 000 dtex/120 f,强度≥0. 099 cN/dtex,断裂伸长率≤20%。

A melt spinning-wet spinning process was introduced to prepare ultra high strength and low shrinkage polypropylene filament. This method used the cooling water tank to cool down the fiber squirted from the spinneret, to replace the existing quenching air, thus effectively avoided filament crystallization between 120 ~ 130 ℃, avoided the crystallization impact on stretch orientation process, improved the consistency of stretch orientation, so as to improve the orientation degree to realize the strength increase of polypropylene, control of fiber elongation at break. The results showed that the slow drawing speed(spinning speed) was set at 100 m/min, the melt index of polypropylene slices was 16 g/10 min, the drying temperature was selected at 75 ℃, the temperature of each area of the screw extruder was controlled at 220~ 260 ℃, the pressure of the extruder was controlled at 8. 0 ± 0. 1 MPa, the number of holes in the spinneret was 120 f, the water temperature of the cooling tank was controlled at 12 ~ 20 ℃, and the spinneret was 3 ~ 10 cm away from the water surface, the temperature of hot roller was controlled at 80 ~ 135℃,which can spin ultra-high strength and low-shrinkage polypropylene filament with excellent performance.The fiber product’s fineness was 1000 dtex/120 f, strength more than 0. 099 cN/dtex and elongation at break less than 20%.