Resin molds for improving thermal management in the injection molding process

Effective thermal management within injection molds is crucial for improving the process energy efficiency. This study presents a novel hybrid mold design, combining steel inserts with polymeric base plates, to enhance thermal insulation and reduce energy consumption. Two mold configurations were experimentally tested on a micro-injection molding machine without active cooling: one made of conventional mold steel and the other using Formlabs White V05 resin. Thermal behavior was analyzed through experimental measurements and finite element simulations using Comsol Multiphysics, with numerical models calibrated using real process data. The results indicate that the hybrid mold retains heat more effectively, achieving higher steady-state temperatures and improved thermal stability during machine stops. At the steady-state regime, the thermal energy stored in the traditional mold insert is estimated at 1 J, while in the hybrid mold it is 2.1 J. The difference is lost by traditional molds since it is dispersed in the surrounding environment. On a limited transient of 164 cycles starting from ambient temperature, the overall advantage of hybrid versus traditional mold in terms of stored thermal energy is estimated at E=506 J (+45%). This amount of thermal energy can be harvested and reused in other phases of the process, such as raw material pre-heating or drying. These results suggest that incorporating polymers as a strategic material in mold design can lead to more energy-efficient injection molding processes.