熔体直纺缝纫线用PA 66纤维生产工艺探讨

Discussion on production process of direct melt-spun PA 66 fiber for sewing thread

以质量分数为48.9%的尼龙66(PA 66)盐液为原料,采用连续聚合-熔体直纺工艺路线,在常规生产线上生产122 dtex/36 f缝纫线用PA 66纤维,重点讨论熔体黏度、缓冷器温度、侧吹风条件、上油率、拉伸倍数、热定形温度等对生产及产品质量的影响。结果表明:控制PA 66熔体相对黏度(83.0±2),缓冷器温度(285±2)℃,侧吹风速度0.2~0.3 m/s、温度22℃,纤维上油率(0.4±0.1)%,拉伸倍数(5.5±0.1),热定形温度(230±2)℃,生产过程稳定,可纺性好;在上述工艺条件下,生产的122 dtex/36 f缝纫线用PA 66纤维A级品率达88%以上,纤维断裂强度高达8.2 cN/dtex,干热收缩率低至3.9%,染色均匀度为3~4级,可满足缝纫线客户的用丝要求。

A 122 dtex/36 f polyamide 66(PA 66)fiber for sewing thread was produced using PA 66 salt solution with a mass fraction of 48.9%as raw material by continuous polymerization-direct melt spinning process on a conventional production line.The effects of melt viscosity,heat retarder temperature,cross air blow conditions,oil content,draw ratio and heat setting temperature on the production and product quality were emphatically discussed.The results showed that the production process was stable and the spinnability was good when the relative viscosity of PA 66 melt was controlled as(83.0±2),the heat retarder temperature as(285±2)℃,the cross air blow speed as 0.2-0.3 m/s and the temperature as 22℃,the oil content as(0.4±0.1)%,the draw ratio as(5.5±0.1),and the heat setting temperature as(230±2)℃;and the A-grade product rate of 122 dtex/36 f PA 66 fiber for sewing thread was above 88%and the produced fiber had the breaking strength up to 8.2 cN/dtex,dry hot shrinkage as low as 3.9%and the dyeing uniformity of 3-4 level under the above process conditions,which can meet the demands of sewing thread customers.