8. Effect of Porosity on Thermal Performance of Plastic Injection Molds Based on Experimental and Numerically Derived Material Properties

Plastic injection molding industry uses traditionally machined tools and dies to manufacture various sizes and shapes of plastic products. With the advent of advanced manufacturing technology and expanding global competition in business, it is necessary to provide innovative solutions to the injection molding industry to sustain their business. Typically, the cooling time comprises more than half of the overall injection molding cycle time. The application of additive manufacturing technique can provide a solution to reduce the cooling time in injection molding process. The potential of 3D printing technology to produce any size and shape of products using metal powders provides an opportunity to design and produce innovative injection molding tools, which is unattainable by traditional machining process. Though the conformal cooling channels are capable of reducing the cooling time significantly, the cost of manufacturing the injection molds by 3D printing is quite high and hence a crucial decision making factor for the mold designers about whether or not to go for the 3D printed molds. By making the molds porous, it is possible to reduce the cost of additive manufacturing, thus creating a positive impact on the use of 3D printed molds in injection molding business. In this paper, the effect of mold porosity on the thermal performance of the injection molds are studied. The properties of 3D printed mold material and traditional mold material is quite different and have been considered for the analysis. An optimization study has been conducted to identify the best possible design solution in terms of thermal and printing cost perspectives.