Design for additive manufacturing: An investigation of key manufacturing considerations in multi-material polyjet 3D printing

The PolyJet material jetting process is uniquely qualified to create complex, multi-material structures. However, there is currently a lack of understanding and characterization regarding important manufacturing considerations to guide designers in their use of the PolyJet process. This paper investigates key considerations necessary to ensure that proposed designs are manufacturable and that part properties are appropriate for the intended use. Considerations included in this paper include 1) minimum manufacturable feature size, 2) removal of support material from channels, 3) survivability of small features during water jet cleaning, and 4) the maximum self-supporting angle of printed parts in the absence of support material. The result of this work is an understanding of which geometric and process variables affect these manufacturing considerations. This understanding is crucial for the creation of a set of Design for Additive Manufacturing (DfAM) guidelines to help designers create ideal, manufacturable parts with less iteration and provide constraints for insertion into automated design processes such as topology optimization.