【摘要】 以相对黏度为2.8的聚己内酰胺(PA 6)切片为原料,采用熔融纺丝结合多级拉伸工艺制备高强PA 6全拉伸丝(FDY);在其他工艺条件一定、侧吹风速度为0.22～0.42 m/s的条件下,研究侧吹风速度对高强PA 6 FDY结构和性能的影响。结果表明:随侧吹风速度提高,高强PA 6 FDY断裂强度变化不大而断裂伸长率有所下降,但二者的变异系数均增加,在侧吹风速度为0.37 m/s时,纤维断裂强度和断裂伸长率均为最小值,分别为7.53 cN/dtex和19.70%;随侧吹风速度提高,纤维条干不匀率、结晶度、干热收缩率均存在极小值,分别为0.941%,29.04%,5.01%,而取向因子存在极大值为0.716;随侧吹风速度提高,纤维(002/202)和(200)晶面的晶粒尺寸分别在侧吹风速度为0.32 m/s和0.37 m/s时有极小值;在纤维成形过程中,侧吹风速度过高,会导致纤维表面形成原纤化结构和皮芯结构;对于高强PA 6 FDY,侧吹风速度的影响更多体现在纤维结构的均一性和性能的稳定性。更多还原

【Abstract】 Using polycaprolactam(PA 6) chip with a relative viscosity of 2.8 as raw material, a high-strength PA 6 fully-drawn yarn(FDY) was prepared by melt spinning and multi-stage drawing process.The effect of cross air blow speed from 0.22 to 0.42 m/s on the structure and properties of high-strength PA 6 FDY was studied under the specific process conditions. The results showed that the breaking strength of high-strength PA 6 FDY changed little and the elongation at break decreased, but their coefficient of variation both increased with the increase of cross air blow speed, and the breaking strength and elongation at break of the fiber were minimized as 7.53 cN/dtex and 19.70%, respectively, at a cross air blow speed of 0.37 m/s; the fiber unevenness, crystallinity and dry heat shrinkage were minimized as 0.941%, 29.04% and 5.01%, respectively, while the orientation factor was maximized as 0.716 with the increase of cross air blow speed; the crystal sizes of the fibers were minimized at crystal planes(002/202) and(200) when the cross air blow speed increased to 0.32 m/s and 0.37 m/s, respectively; the extremely high cross air blow speed could lead to the fibrillation structure and skin-core structure during the process of fiber formation; and the cross air blow speed gave more effect on the structure uniformity and the properties stability of high-strength PA 6 FDY.更多还原