An experimental and theoretical investigation of surface roughness of poly-jet printed parts This paper explains how local surface orientation affects surface roughness in a poly-jet process

The present study has attempted to investigate and model surface roughness on parts printed using a poly-jet additive manufacturing system. Initially the study investigated the effect of layer thickness, local surface orientation and finish type on surface roughness in poly-jet printed parts. The study shows that the surface orientation and finish type are the major factors affecting surface roughness of poly-jet parts. Then a detailed experimental study was conducted by varying surface orientation in very close intervals to obtain the surface roughness distribution. The study reveals that surface roughness distribution for poly-jet parts is different from that obtained for parts made by other additive manufacturing processes. A detailed experimental and theoretical analysis of droplet geometry, as formed by the jetting process, and its effect on the edge profile of the polymerised layer is presented. A surface roughness prediction model is proposed based on these studies and validated using profilometric measurements.