Advanced Study on Non-Newtonian Flow of Polymer Melts in Extrusion Die of Plastic Net

Abstract

Abstract Broken section method is extended to analyze theoretically non-Newtonian flow of polymer melts with power law in the extrusion die of plastic net, in consideration of transversal drag action by die rotation. Die lip having overlap profile of semi-circle is broken into many sections, perpendicular to rotating boundary line. Computer approach is applied to analyze numerically the flow in each broken section. The flow isovels in discharge direction are indicated in various values of flow index and overlap ratio of upper and lower die lips. With increasing non-Newtonian behaviour, the profiles of the isovels in discharge direction are flattened and the area of the isovels of 0.9 increases to shift its location downwards. The flow isovels in rotating drag direction is plotted only in the case of half overlap ratio. With the decrease of flow index, the positive velocity profile in drag direction is flattened for larger area to cancel the sharp negative velocity near rotating drag boundary. Volumetric R...