喷头拉伸对超高分子量聚乙烯后续牵伸的影响

Effect of the Draw-down Ratio on the Follow-up Draft of Ultra-high Molecular Weight Polyethylene

利用干法纺丝制备超高分子量聚乙烯纤维,研究了喷头拉伸对超高分子量聚乙烯后续牵伸的影响。通过张力仪测量不同喷头拉伸倍率下的张力,计算出拉伸应力。利用拉伸应力—粘滞二元组合模型,计算机拟合出NSkT值,根据该值确定喷头拉伸倍率。结果发现,13倍的喷头拉伸能够使最大后续牵伸倍率达到23.3倍,最终的纤维强度和模量分别为30cN·dtex-1和1200cN·dtex-1。

Ultra-high molecular weight polyethylene fibers were prepared by dry spinning and the effect of the draw- down ratio on the follow-up draft of UHMWPE was studied on. The extensional forces in the draw-down process were measured at the exit of the spinning duct by tension meter and the tensile stresses of the draw-down were calculated. Based on the two-component model of tensile stress-viscosity,the N, kT values were calculated in the fitting process and then the draw-down ratios were determined. The results showed that the maximum follow-up draft ratio was 23.3 and the fiber strength and modulus were 30cN.dtex-1 and 1200cN.dtex-1 respectively when the draw-down ratio was 13.