Effect of styrofoam particles on the surface roughness of lost foam casting with EPS pattern

The effects of the grain size and grain gradation of styrofoam particles as well as the expendable polystyrene (EPS) forming tools on the surface roughness of EPS patterns were studied in the paper. The results show that with the decrease of pre-expended polystyrene grain size, the surface roughness of EPS patterns decrease under the same processing parameters. The grain size gradation of styrofoam particles could reduce the surface roughness of EPS patterns evidently. The EPS pattern possesses the lowest surface roughness when the volume ratio of the polystyrene particles (with grain size of 30 grades and 40 grades) was 1:1. With the decrease of surface roughness of forming tools, the surface roughness of EPS pattern and casting are decreased.