细旦高强聚乙烯纤维加工过程研究

Study on the manufacturing process of the fine-denier and high-strength ultra-high molecular weight polyethylene fibers

通过对不同生产厂家的超高分子量聚乙烯(UHMWPE)树脂的黏均分子量、结晶度、溶胀后料液的流变特性等物化性质进行对比和分析,采用凝胶纺丝-超高倍拉伸技术对UHMWPE树脂进行纺丝,制备了细旦高强超高分子量聚乙烯纤维,对纤维的结晶度、纤度及力学特性进行了测试分析。结果表明,UHMWPE树脂的结晶度、颗粒大小等物理特性对制备的成品纤维的性能有较大的影响,树脂的黏均分子量与其结晶度不成正相关,而与其制备的成品聚乙烯纤维的结晶度成正相关,且结晶度越高制备的纤维性能更优异;黏均分子量大、原料液较优的流变特性均有利于双螺杆的加工,其成品纤维的强度、模量均较高,黏均分子量大、粒径分布窄,更有利于制备细旦高强超高分子量聚乙烯纤维,同时,超倍机械热牵伸是目前提高超高分子量聚乙烯纤维力学性能较有效的方法。

The relative molecular weight(viscosity-average molecular weight),crystallinity and rheological properties of ultra-high molecular weight polyethylene(UHMWPE)resins from different manufacturers are compared and analyzed.The UHMWPE fibers are prepared by gel spinning-ultra high-power stretching technology.The crystallinity,fineness and mechanical properties of the fibers are tested and analyzed.The results show that the physical properties such as crystallinity and particle size of the UHMWPE resins have a great influence on the spinning process of the raw material solution and the performance of the finished fibers.The viscosity-average molecular weight of the resins are not positively correlated with the crystallinity,but are positively correlated with the crystallinity of the finished polyethylene fibers.The higher the crystallinity is,the better the performance of the fibers is.The high viscosity-average molecular weight and excellent rheological properties of the raw material solution are conducive to the processing of twin-screw.The strength and modulus of the finished fibers are relatively high,and the viscosity-average molecular weight is large and the particle size distribution is narrow,which is more conducive to the preparation of fine-denier and high-strength ultra-high molecular weight polyethylene fibers.At the same time,the ultra-doubling mechanical thermal drafting is the most effective method to improve the mechanical properties of ultra-high molecular weight polyethylene fibers.