采用恒速型双毛细管流变仪研究聚丙烯熔体在高速流场中的流变特性。结果表明,高速挤出时挤出物出现螺旋状挤出外观,这种不稳定现象是由熔体在人口区存在扰动造成的。螺旋挤出畸变与剪切速率、温度、材料种类、口模长径比以及材料黏弹性有关。
The rheology behavior of polypropylene extruded at high speed was studied by a constant speed double-capillary rheometer. The results show that the coil which is caused by the disturbance of polypropylene in the inlet appears in high speed extrusion of polypropylene. The phenomenon is related to shear rate, temperature, material species, die slenderness ratio and viscoelasticity of materials.