An Investigation of Key Design for Additive Manufacturing Constraints in Multimaterial Three-Dimensional Printing

The PolyJet material jetting process is uniquely qualified to create complex, multimaterial structures. However, key manufacturing constraints need to be explored and understood in order to guide designers in their use of the PolyJet process including (1) minimum manufacturable feature size, (2) removal of support material, (3) survivability of small features, and (4) the self-supporting angle in the absence of support material. The authors use a design of experiments (DOE) approach to identify the statistical significance of geometric and process parameters and to quantify the relationship between these significant parameters and part manufacturability. The results from this study include the identification of key variables, relationships, and quantitative design thresholds necessary to establish a preliminary set of design for additive manufacturing (DfAM) guidelines for material jetting. Experimental design studies such as the one in this paper are crucial to provide designers with the knowledge to ensure that their proposed designs are manufacturable with the PolyJet process, whether designed manually or by an automated method, such as topology optimization (TO).