The effect of heterogeneity on the flow behavior on high density polyethylene

The effect of heterogeneity on the flow behavior of high density polyethylene (HDPE) has been studied by systematically homogenizing heterogeneous blends and observing the effect on the basic rheological parameters and on the extrudate surface appearance. Ample evidence is presented to show that heterogeneity causes substantial changes in the flow behavior although molecular parameters obtained through solution studies are unchanged. A simplified mathematical model which clearly illustrates the effects of the size of these flow units on the flow behavior is presented.