环形微孔中钢针缩进量对中空纤维中空度和挤出胀大的影响

The effect of the indentation amount of the steel needle in annular microspores on the hollowness and extrusion swell of hollow fiber

利用Polyflow数值模拟法,对使用圆形微孔内置同轴心钢针法纺制中空纤维过程中聚合物熔体的流速分布进行模拟。分析了钢针缩进量不同时,聚合物熔体在微孔内的流速分布变化和挤出胀大反应,以及聚合物熔体挤出胀大比的变化趋势和中空纤维中空度的变化。结果表明聚合物熔体的挤出胀大比随钢针缩进量的增大而逐渐增大;中空纤维的中空度与钢针缩进量呈非线性关系;钢针缩进量为0.05 mm时,所制备的中空纤维的中空度最大,钢针缩进量为0.20 mm时,中空纤维的中空度趋于0。试验结果与模拟结果良好的吻合性说明,本文建立的模拟方法具有一定的可行性和可靠性。

The Polyflow numerical simulation method was used to simulate the melt flow velocity distribution during the hollow fiber forming process through using a circular microporous built-in coaxial steel needle.Then,investigation on the trend of the melt flow velocity in the microspores and the extrusion swell reaction,as well as the variation of extrusion swell ratio and the hollowness changes of hollow fibers under different indentation amount of the steel needle was carried out.The results showed that the extrusion swell ratio gradually increased with the increasing of the indentation amount of the steel needle.The hollowness of hollow fiber was nonlinearly related to the indentation amounts of the steel needle.The hollowness of the hollow fiber would reach the largest when the indentation amounts of the steel needle was 0.05 mm,and the value approached zero when the indentation amounts of the steel needle was 0.20 mm.The good agreement between the experimental results and the simulation results indicated that the simulation method established in this paper was feasible and reliable.