采用双毛细管流变仪研究由限定几何构型催化剂和INSITE^TM工艺开发的聚烯烃弹性体(POEEngage)和三元乙丙橡胶(EPDMNordel IP)在高速挤出时的不稳定流动现象和挤出畸变特征,并对各类不同挤出畸变的扰动源进行了探讨。结果表明,鲨鱼皮和螺纹状畸变的空间起源在口模出口处,竹节状黏-滑畸变与挤出压力振荡现象是由于熔体/口模壁处的整体黏-滑转变引起,而熔体整体无规破裂现象则与口模入口区的扰动有关。
The melt flow instability behavior and the causes of the extrusion distortion of POE Engage and EPDM Nordel IP produced by CGC and INSITETM technology were systematically studied using a double capillary rheometer at constant speed. The result indicated that the sharkskin fracture was caused by the interface instability at die exit and the extrusion pressure oscillation was due to the stick-slip transition at the interface between the melts and die wall. However, the random fractures were related to the flow turbulence at the die entrance.