挤出压力波动与熔体挤出畸变的关系

The Relationship Between Extrusion Pressure Oscillations and Extrudate Distortions of Polymer Melts

采用双筒毛细管流变仪研究挤出压力与熔体挤出畸变的关系。结果表明,高速挤出时挤出压力因流动应力集中效应而发生波动;压力波动分口模内压力波动和入口压力波动2类;不同结构聚合物熔体在流场的应力集中效应不同,因此发生压力波动的位置和性质不同;压力波动的信号特征和强度直接与挤出畸变特征和强度关联。

The relationship between extrusion pressure and extrudate distortions of melts was studied by a double-capillary rheometer. The results show that by high speed extrusion the extrusion pressure oscillations occures when the flow stress concentrations are strong. The pressure oscillations can be divided into two types, inlet pressure oscillation and capillary pressure oscillation. The flow stress concentrations of polymer melts with various structures are different, therefore the places and natures of pressure oscillations are also very different. The signals and strength of the pressure oscillations are directly related to the features of extrusion distortions.