Wall friction of fine granular plastic powders

Wall friction is an important parameter in the handling of fine granular materials. In the selection of wall material, a small wall friction angle between the powder and the wall material is often an important target. However, there is little information available about the wall friction of different plastic powders. In this study, the wall friction of various fine granular plastic powders with three different wall materials (stainless steel 1.4301, aluminum alloy 3.3535 and a UHMW polyethylene) was determined. For most materials a significant dependence of the wall friction angle on the wall normal stress was observed. However, no general trend was found for the wall material with the lowest wall friction angle.