热拉伸工艺对聚甲醛纤维结构与性能的影响

摘要

采用自主开发的熔融纺丝设备制备了聚甲醛(POM)初生纤维,将POM初生纤维在130℃下,经热辊或热管在不同拉伸倍数下进行热拉伸制得POM纤维,研究热拉伸工艺对POM纤维结构与性能的影响.结果表明:随着拉伸倍数的增大,POM纤维取向度、结晶度和断裂强度逐渐增大,条干均匀性逐渐得到改善;在相同拉伸倍数(5～7)下,热辊拉伸得到的POM纤维比热管拉伸得到的POM纤维的取向度和结晶度高、强度好,但条干不匀率高;热管拉伸可实现高倍拉伸,最高可拉伸14倍,而热辊拉伸最高可拉伸7倍;热管拉伸14倍时制得的POM纤维力学性能最佳,其断裂强度可达10.76 cN/dtex,断裂伸长率为9.6％;热辊拉伸7倍时,制得的POM纤维力学性能最佳,其断裂强度可达6.92 cN/dtex,断裂伸长率为12.8％.%As-spun polyoxymethylene ( POM) fibers were prepared on self-developed melt spinning equipments and were pro-duced into POM fibers by hot drawing process at different draw ratios through hot rollers or hot pipes at 130℃.The effects of hot drawing processes on the structure and properties of POM fibers were studied .The results showed that the orientation degree , crystallinity and breaking strength of POM fibers were gradually increased and the yarn evenness was gradually improved with the increase of the draw ratio;POM fibers drawn by hot rollers had higher orientation degree , crystallinity, strength and yarn uneven-ness as well than those drawn by hot pipes under the same draw ratios of 5-7; moreover , the hot pipe drawing process could proceed at high ratios which could be maximized as 14 when the maximum draw ratio for hot roller drawing process could be 7;and these two kinds of drawing processes both contributed the optimal mechanical properties to POM fibers at the maximum ratio , and the POM fibers by hot pipe drawing process exhibited the breaking strength up to 10.76 cN/dtex and the elongation at break of 9.6％when the POM fiber by hot roller drawing process showed the breaking strength of 6.92 cN/dtex and the elongation at break of 12.8％.