双螺杆纺丝工艺对高相对分子质量聚乙烯纤维结构性能的影响

Effect of twin-screw extruder spinning technology on the structure and properties of high molecular weight polyethylene fibers

采用双螺杆溶胀溶解和挤出纺丝技术,探讨高相对分子质量聚乙烯(HMWPE)的冻胶纺丝工艺,研究纺丝原液质量分数、纺丝温度及双螺杆转速对HMWPE纤维结构性能的影响。结果表明:随着纺丝原液质量分数的增加,HMWPE冻胶纤维内晶粒尺寸和结晶度减小,晶面间距增大,纤维熔点降低;在HMWPE质量分数为20%～40%及纺丝温度为240～290℃范围内,制得纤维的力学性能随着纺丝原液质量分数的增加或纺丝温度的升高而降低;随着螺杆转速的提高,纤维的力学性能先升高后降低。在最佳纺丝温度和螺杆转速下,由40%HMWPE制得的纤维的线密度近100 dtex,强度达12.3 cN/dtex。

By the means of twin-screw swelling, dissolving and extruding, the gel spinning technology of high mo- lecular weight polyethylene （HMWPE） was discussed. The effects of HMWPE concentration, spinning temperature and twin-screw rotating rate on the structure and properties of resultant HMWPE fibers were investigated. The results showed that the average crystal sizes and overall crystallinity of gel fibers decreased with the increase of HMWPE concentration, the interplanar distance increased and fibers＇ melting temperature reduced. The mechanical properties of fibers decreased as HMWPE concentration increased from 20% to 40% or as the spinning temperature increased from 240 ℃ to 290 ℃. With the increase of screw rotating rate, the tenacity of HMWPE fibers increased at first, and then it distinctly decreased as the rotating rate was higher than 4.41 r/min. The linear density of 40% HMWPE fiber, prepared at optimal spinning temperature and optimal screw rotating rate, was up to 100 dtex, and the tenacity was up to 12.3 cN/dtex.