Effect of Surface Slope and Build Orientation on Surface Finish and Dimensional Accuracy in Material Jetting Processes

This work seeks to elucidate the effect of surface slope and build orientation upon the surface finish and dimensional accuracy of specimens fabricated by material jetting processes. Specimens with a flat area and four feature designs (i.e., spherical and prismatic hole and protrusions) were printed in two orientations (i.e., along (XY) and across (YX) the print head direction) and two surface slopes (i.e., horizontal (0∘) and 45∘) and scanned with a white-light profilometer to quantify the surface texture, areal, and material ratio parameters for dimensional accuracy and areal fidelity. The results indicate that surface slope and build orientation appear to have a greater influence on the recessed features compared to the protruded ones. The height and volumetric functional surface parameters are significant and show better surface finish for the 0∘ surface slope compared to 45∘. Also, prismatic and recessed features might benefit from printing on a 45∘ sloped surface while the design fidelity of cross-sections in holes and protrusions greatly vary depending on the specimen slope. The contributions of this work include illustrating the potential for increased production, resolution and fidelity capabilities if 3D printing equipment could incorporate tilting print trays, adaptable print orientation, and local angles, among others