PREDICTING THE FLOW BEHAVIOR OF POWDERS, WITH PARTICULAR REFERENCE TO ROTOMOLDING MATERIALS

摘要

The rotomoulding industry uses a simple but crude measure to assess the flowability of powders, which involves timing the discharge of powder through a funnel with a circular bottom orifice. The flow of granular materials through orifices has been the subject of considerable research elsewhere and equations exist that relate flow to the various parameters involved. The most well accepted formula was assessed for its suitability to typical rotomoulding materials, as well as a variety of other powders and granulates. The characteristics of many materials (including rotograde micropellets) showed good correlation to theoretical predictions. Polyethylene and polypropylene rotograde powders showed behaviour that could be described by a modified version of the existing equation.