On the correlation between pre-processing workflow and dimensional accuracy of 3D printed parts in high-precision Material Jetting

Material Jetting (MJ) is distinguished in the additive manufacturing field for its ability to create accurate multimaterial functional objects with features in the range of few micrometers. Analyzing the impact of each step in MJ from virtual design to 3D printed object on the process response is essential for optimizing the technology's capabilities. The current state-of-the-art reveals a gap in MJ regarding the fundamental understanding of the correlation between the pre-processing workflow and the geometrical and dimensional accuracy. This study aims to bridge this gap by examining factors such as utilization of different CAD software with diverse working principles, part-based versus assembly-based design, alternative 3D model formats (STL, OBJ, 3MF, AMF, STP), and slicing approaches (using open-source slicers). Two test specimens, each containing ten elements (either cylinders or hemispheres) with diameters ranging from 254 mu m to 12.7 mm are examined. The results demonstrate the significant influence of the aforementioned factors on geometrical and dimensional accuracy, except for 3D model formats. Specifically, for large elements, the achievable accuracy depends on the tessellation approach of the CAD system, while for very small elements, the rasterization process is defining, and designing in assembly mode can further enhance accuracy. ... mehrThe handling of the 3D model by the slicer particularly affects geometrical accuracy. Experimental validation confirms the impact of the pre-processing workflow, though the data-related dimensional deviation for the base layer is masked by the wetting behavior of the dispensed droplets on the substrate.