Research into Melt Flow Properties of Polypropylene/Diatomite Composites

Abstract

Polypropylene (PP) filled with diatomite particles was manufactured using a twinscrew extruder. Melt volume flow rate (MVR) is an important parameter for characterization of flow properties of polymer. The MVR of the PP/diatomite composites was measured by means of a melt flow rate instrument to investigate the effects of die diameter and extrusion conditions (temperature 210—230°C, load 5.0—12.5 kg) on the melt flow properties of the composite systems. The results showed that the MVR of the composites increased as a quadratic function with the increase of the die diameter, while it decreased with increase of particle size; the MVR was a linear function of temperature when the die diameter and load was constant; and the MVR was also a quadratic function of the die diameter when load and temperature were fixed. In addition, the effects of load, temperature, and particle size on the MVR was enhanced with an increase in the die diameter.