Polymeric advancements in innovating wax injection molds using aluminum-filled epoxy resin with face-cooled waterfall cooling channels

Abstract

Aluminum-filled epoxy resin is a polymer composite material formed by adding aluminum particles to epoxy resin, which is widely used to make a rapid tool for developing new prototypes in the research and development department. A conformal cooling channel (CCC) facilitates the swift and even cooling process in injection molding. Nevertheless, the considerable drawback of CCC lies in the notable pressure drop along the cooling channels. This study introduces an inventive solution known as the waterfall cooling channel (WCC), which was proposed and fine-tuned through optimization using Moldex3D simulation software. Two sets of aluminum-filled epoxy resin injection molds were designed and employed, featuring distinct cooling channels. The cooling time for the injection molded part was assessed using a low-pressure wax injection molding machine. Experimental results regarding the cooling time were then juxtaposed with simulation outcomes obtained from Moldex3D software. It was found that a mesh size of 1 mm is the optimal decision for molding simulation based on both the cooling time of the injection molded part and the total computation time. The maximum flow velocity of the cavity insert can be increased by 9.7 % using WCC. A reduction in the coolant flow length of the WCC is about 29–50 % compared to CCC. A reduction in the pressure drop of the WCC is about 58–61 % compared to CCC. The difference in cooling efficiency for CCC is 6 %, while the difference in cooling efficiency for CCC is 4 %. The heat flux of WCC is about 21 times larger than that of CCC. Taking a water cup as an example, the experimental results confirmed that an aluminum-filled epoxy resin injection mold embedded with WCC can increase cooling efficiency by about 16.4 % compared to an aluminum-filled epoxy resin injection mold embedded with CCC.