Effects of Formulation and Processing Parameters on the Morphology of Extruded Polypropylene-(Waste Ground Rubber Tire Powder) Foams

摘要

This paper presents an experimental study of the foaming behavior of polypropylene (PP)/(waste ground rubber tire powder) (WGRT) blends when using a chemical blowing agent in an extrusion foaming process. The effects of formulations (i.e., WGRT content, blowing agent content, compatibilizer) and the processing parameters (i.e., the temperature, screw speed) on the void fraction, average cell size, cell density, and cell morphology of the PP/WGRT foams were investigated. The blowing agent loading affected the cell structure of the foams and the average cell size, and the void fraction increased with increasing blowing agent loading. Both increasing the screw speed and decreasing the the temperature could establish a high pressure drop in the extruder die, and these were beneficial to the foaming extrusion.