Measurement of the high rate flow properties of filled HDPE melts by capillary rheometer: Effects of the test geometry

A die diameter effect on the pressure drop localized at the die entrance was clearly observed for the unfilled HDPE; for the micro-filled melts, this effect was either enhanced or considerably reduced, depending on the type of filler (opposite effects were induced by glass beads and by glass fibres). A die diameter effect on the macroscopic shear viscosity response was noticed only for the melts filled with particles with relatively high aspect ratio (glass fibres and talc platelets).