Influence of talc in polypropylene foam cores of sandwich structures with skins made of thermoplastic prepregs

Properties of sandwich structures with a core of thermoplastic foam depends on cell size and cell density (cell number). Nucleating agents have a benefit to generate cell nucleation, which affects an increase in the cell density. In this study, sandwich structures composed of a polypropylene (PP) foam core and organic sheet skins in-situ produced by injection moulding process. A chemical blowing agent was employed to generate cellular structure in the core. The influence of the varying nucleating agent content with the same chemical blowing agent content on density, cellular structure and mechanical properties of the sandwich structures were investigated. The talc contents had a slight influence on the density of the sandwich structures. Moreover, flexural modulus and flexural strength of the sandwich structures consisting of the foam core with 4 wt% of talc were higher than the foam core without talc. However, the utilization of these talc contents with PP and the chemical blowing agent had no significant effect on the reduction of the cell size and the increase of the cell density.