加捻对聚四氟乙烯纤维性能的影响

Effect of twisting on properties of polytetrafluoroethylene fiber

以膜裂法制备的聚四氟乙烯(PTFE)扁丝为原料,通过加捻制备PTFE加捻长丝,考察了加捻对PTFE加捻长丝力学性能、条干不匀率、热收缩性能、表面形貌的影响。结果表明:PTFE加捻长丝的断裂强度随着捻度的增加先增加后降低,当捻度达到600捻/m之后,加捻长丝的断裂强度达到最大值2. 14 c N/dtex,比未加捻的PTFE扁丝提高了67. 2%;断裂伸长率随捻度的增大呈现逐渐增大的趋势,当捻度为600捻/m时,长丝断裂伸长率为22. 5%; PTFE扁丝比PTFE加捻长丝具有更好的条干均匀度;加热温度对PTFE加捻长丝的热收缩率有比较明显的影响;拉伸过程中的摩擦作用会使长丝线密度减小,毛羽增多,条干不匀增加。

Polytetrafluoroethylene(PTFE)flat fiber prepared by film-splitting method was used as raw material to produce twisted PTFE filament by twisting process.The effects of twisting process on the mechanical properties,yarn unevenness,thermal shrinkage and surface morphology of twisted PTFE filament were investigated.The results showed that the breaking strength of twisted PTFE filament was increased and then decreased with the increase of twist and was maximized as 2.14 cN/dtex at the twist of 600 twist/m,with a growth of 67.2%as compared with that of untwisted PTFE flat fiber;the elongation at break was gradually increased with the increase of twist and was up to 22.5%at the twist of 600 twist/m;PTFE flat fiber was superior to twisted PTFE filament in yarn evenness;the heating temperature gave an obvious effect on the thermal shrinkage of twisted PTFE filament;and the friction during the drawing process caused the lower linear density,more hairiness and yarn unevenness growth of the filament.