Utilization of Additive Manufacturing for Batch Production Injection Mold Inserts

Abstract A potential drawback of polymer injection molding is the relatively high cost of metal mold inserts. This limits a manufacturer’s ability to capitalize on smaller customized product batches and in-house cavity prototyping. To overcome this, manufacturers have found success in the use of polymer-based 3D printed molds. Professional grade stereolithography ultraviolet (SLA UV) resins have become standard materials for 3D printed molds, but there is little documentation concerning the use of other commercially available polymers. This includes materials used in inexpensive Fused Deposition Modeling (FDM) and SLA printers. The research presented in this paper explores this aspect of additive mold technology. Mold inserts composed of polylactic acid (PLA), polyethylene terephthalate glycol (PETG), acrylonitrile butadiene styrene (ABS), polycarbonate (PC), nylon, carbon fiber polylactic acid (CF PLA) and 405 nm photopolymer resin were compared with various physical metrics. By tracking the dimensional accuracy and flash sizes over the course of 50 mold shots, the rates of cavity degradation for each insert were compared. The results of this study concluded that the most sustainable polymer mold cavity is composed of ABS or a Carbon Fiber reinforced polymer. This is followed by PC, PETG, resin, nylon, and PLA.