Numerical study of rapid cooling of injection molds

Abstract

Rapid heat cycle molding (RHCM) technology has become an alternative for classic injection molding and it is consist of the rapid control of the temperature of mold or forming surfaces. Despite widely used in the plastics industry, there are some problems with rapid, balanced cooling. The primary problem during the cooling stage is to ensure the balanced and uniform heat removal from cooled material and suitable dynamic of the entire process, as to avoid molding’s defects. This article presents the simulation research of various geometry of cooling channels, which can be used in RHCM technology to improve the efficiency of a cooling process. Authors proposed the use of finned channels, which can guarantee the most effective heat transfer. The analysis and comparison of proposed channels show the advantage over conventional channels commonly used in injection molds. To more clearly show the correlation between the geometry of cooling channels, the flow state of working fluid and the heat transfer, the dependencies of the Nusselt and the Reynolds number are evaluated and presented. The investigation results lead to possibility of reducing the cooling phase and thus the production time of entire injection cycle.