切片纺超高强涤纶短纤维生产工艺探讨

Discussion on production process of ultrahigh-strength polyester staple fiber by chip spinning route

采用切片纺丝路线,探讨采用不同特性黏数([η])的聚对苯二甲酸乙二醇酯(PET)切片制备超高强涤纶短纤维的可行性;并选用[η]较高的PET切片在切片纺工业化涤纶短纤维装置上通过纺丝温度、拉伸倍数、拉伸温度和热定型温度等工艺参数的调整优化,试生产超高强涤纶短纤维。结果表明:采用[η]较高的PET切片,选择合适的纺丝和后加工条件可以生产超高强涤纶短纤维;选择[η]为0.731 dL/g的PET切片为原料,在7500 t/a切片纺涤纶短纤维装置常规生产工艺基础上,调整纺丝螺杆温度为290~295℃、箱体温度为296~300℃,初生纤维断面不匀率小于等于1.21%,纺丝状况良好;调整水浴拉伸温度为70℃、总拉伸倍数为3.878、热定型温度为185℃,试生产的涤纶短纤维结晶度和非晶区取向有所增大,断裂强度达7.02 cN/dtex,达到了超高强纤维的要求。

The feasibility of preparing ultrahigh-strength polyester staple fiber from polyethylene terephthalate(PET)chips with different intrinsic viscosity([η])was discussed by chip spinning route.The PET chips with higher[η]were selected to produce ultrahigh-strength PET staple fiber by adjusting and optimizing the spinning temperature,draw ratio,drawing and heat setting temperature on a commerical chip spinning unit for polyester staple fiber.The results showed that ultrahigh-strength PET staple fiber can be produced by using PET chips with high[η]under suitable spinning and post-processing conditions;the spinning status was good on the conventional production process basis of 7500 t/a PET staple fiber unit and the cross section irregularity of the as-spun fiber was not higher than 1.21% when PET chip with[η]of 0.731 dL/g was selected as raw materials at the screw temperature of 290-295℃ and the box temperature 296-300℃;and the crystallinity and orientation of amorphous region of PET staple fiber increased and the breaking strength reached 7.02 cN/dtex,satisfying the requirement of ultrahigh-strength fiber,while controlling the water bath drawing temperature 70℃,total draw ratio 3.878 and heat setting temperature 185℃.