The Effect of Build Orientation on the Mechanical Properties in Inkjet 3D Printing

It is known that part orientation plays an important role in 3D printing and especially in inkjet 3D printing, where the layers are more distinct than in other processes. Despite many investigations in this direction, previous research focused mainly on build orientations along the three main axes X, Y and Z. For advanced purposes such as optimization, however, it is important to know what happens in combined alignments between the main axes. The authors hypothesize and show that the transition is not linear and that, despite prior studies, the weakest properties are not found when the parts are aligned along the Z direction. The discovered effects can partially be attributed to shear forces in the material, which act between the layers when the parts are not aligned orthogonally to the main axes. To accurately characterize the three-dimensional space, the mixture design method has successfully been introduced to the area of 3D printing and proven to be an efficient tool that can also be used for other processes. With the results of this study, designers and engineers are now able to analyze and predict part properties on a much higher level than before.