Polystyrene powder materials for selective laser sintering

Polystyrene (PS) is a widely used matrix material in selective laser sintering (SLS). Polystyrene is inexpensive and its powdered form, used as a matrix material in selective laser sintering, enables high accuracy in prototype production, similar to the casting process of wax molds. However, the performance of polystyrene varies significantly due to the differences in its synthetic process and added fillers of different grades available in the market, leading to varying outcomes when used in selective laser sintering technology. Therefore, it is necessary to study the polystyrene materials available in the market to identify the most suitable ones for selective laser sintering technology. In this study, three different grades of polystyrene powder (75–100 µm) were selected as research objects and treated to sintering experiments using a “selective laser sintering” rapid prototyping machine. The research results indicated that the molecular weight affects the quality of selective laser sintering parts by influencing the melt viscosity of polystyrene, which in turn affects the density and accuracy of the fabricated parts. Guided by these research findings, two 75–100 µm polystyrene powder materials were selected, and their sintering performance and thermal weight loss characteristics were investigated. Under optimized processing parameters, the test specimens with high accuracy were fabricated by selective laser sintering, and its mechanical property was further reinforced through epoxy resin post-processed, and the microstructure of the tensile fracture surface was examined using electron microscopy. In conclusion, the PS1 type polystyrene material and its process parameters, suitable in selective laser sintering and its post-processing, were determined. The research findings presented in this paper provided a methodology for the selection of selective laser sintering materials.