Laser Polishing of Polymer Parts Produced with Material Jetting Technology: Effect of Laser Scan Speed, Overlapping and Loop Cycles

In the last year, the industrial production is characterized by the request of high level of product variety that generates a decrease of production volume changing manufacturing from mass production to mass customization. This trend let the conventional production processes, as forming, casting or moulding, expensive because of initial tools production cost that is not more amortized by the high-volume production. A solution to this scenario is to integrate Additive Manufacturing in tools production; this solution guarantees tools cost reduction also if post processes operations are needful to reduce the surface roughness produced by additive processes. Among additive processes, Material Jetting is able produce parts with guaranteed high accuracy and low average surface roughness (0.5 µm). However, these standards mainly refer to upfacing surfaces parallel to the print plate, and the roughness obtained on the other surfaces could increase up to 15 µm because of production mechanism. To improve parts roughness in this study, the laser polishing process was tested; different experimental tests were executed to investigate the effects of scan speed, overlapping and loop cycles. The results demonstrated that it is possible to improve the surface finish and reduce the roughness by 70% at the expense of dimensional accuracy.