ABSTRACT Additive manufacturing (AM) introduced the concept of layer‐by‐layer manufacturing, which allows the fast and direct production of parts. Additive technologies are also hybridized with conventional polymer processing technologies. Polymeric AM technologies can process high‐performance, thermoset photopolymer resins. The two applicable photopolymer‐based AM technologies are material jetting (MJ) and digital light processing (DLP). MJ also allows multi‐material printing where the part can be printed from multiple different resins, which combines the beneficial properties of individual components. Both multi‐material jetting and high‐speed digital light processing are promising new technologies for rapid tooling, but their applicability is barely analyzed. In our study, we characterized two new photopolymers: Stratasys Tough One and Loctite IND 147 thermomechanically and printed injection mold inserts from them for production trials. Their stiffness and creep were measured by dynamic mechanical analysis (DMA). IND 147 showed outstanding performance because of the high modulus and excellent creep resistance even at elevated temperatures. Tough One also showed suitable stiffness and creep resistance. After that, during injection molding tests with the two resin inserts, strain, temperature, and cavity pressure of the inserts were measured. IND 147 showed lower deformations than Tough One, which correlates with the material tests. However, due to its brittleness, the IND 147 insert broke, while the Tough One insert survived the test. The choice of photopolymer always has to be a compromise between strength and creep resistance on the one hand, and impact and shock resistance on the other. Our findings help the more widespread use of new, multi‐component, high‐performance photopolymers in demanding applications.
Krizsma et al. (Thu,) studied this question.