Development of direct metallic rapid tooling technologies to produce injection mold

Rapid prototyping (RP) is a technology that uses layer additive concept to build 3D parts. Rapid tooling (RT) technology is a natural extension of RP. RT can be used to produce temporary molds as well as permanent molds in mass production. RT provides more benefits from the design stage to mass production. The objective of this paper is to develop the Direct Metallic Rapid Tooling System which can be used to fabricate the plastic injection mold inserts. A 2.5KW Nd-YAG laser system, a metallic powder feeder system, a lateral powder nozzle system, a PC-based motion controller, and a shielding gas supply system are incorporated for the hardware architecture in the proposed RT System. The critical process parameters influencing the dimensional accuracy were analyzed with Taguchi's experimental design. From the ANOVA (Analysis of Variance) computational results, the factors "Scanning speed" and "Tool path offset" are the influential factors affecting the layer thickness of RT parts. From the experimental results, the proposed RT system could fabricate the mold inserts. After finishing the mold inserts and assembling the plenary injection mold, the injection molding machine can generate ABS plastic parts with excellent quality.