熔喷非织造布用聚丙烯材料的挤出胀大行为

Extruded swell behavior of polypropylene specialized for manufacture of meltblown nonwoven fabric

为确定不同因素对熔喷非织造布专用料挤出胀大行为的影响,采用毛细管流变仪,对不同温度、长径比、剪切速率、熔融指数等条件下熔喷非织造布专用聚丙烯材料的挤出胀大行为进行系统研究。结果表明熔喷非织造布专用聚丙烯材料的挤出胀大比受多种因素的共同影响。在熔喷非织造布的生产过程中,可通过选用高熔融指数的原料、提高加工温度、加大喷丝板长径比、优化喷丝孔入口角度等方式消除挤出胀大现象,减少并丝,提高非织造布质量。

The effects of temperature, length/diameter ratio, shear rate and melt flow index （MFI） on the die swell behavior of polypropylene （PP） specialized for meltblown nonwoven fabric were investigated using a capillary rheometer to provide the optimal processing parameters to prepare meltblown nonwovens. As a result, the die swell behavior of PP is dependent on various factors. Such methods as using high-MFI PP, improving the process temperature, enlarging the length/diameter ratio and optimizing the inlet angle of the orifice can be taken to diminish the die swell behavior of PP and decrease the folding and diameter of the fibers.