Thermal optimization of porous mold inserts for rapid heat cycle molding

Rapid heating cycle molding (RHCM) is a widely used technology for manufacturing high gloss components without visible surface defects. A common solution to thermally cycle the mold temperature consists in alternating two heating and cooling fluids in the mold. These fluids impose a convective heat flux at the fluid-solid interface. To reduce the heating and cooling cycle time and to decrease energy consumption conventional channels have recently been replaced with porous mold inserts. In this work a porous mold insert with a regular deterministic geometry was developed and optimized by means of numerical simulations to increase heat exchange between water and the cavity surface. The materials employed and the inserts structures were studied to obtain an efficient thermal convection without impairing the mold integrity. An accurate numerical model of the mold was developed and experimentally validated. The results of the work showed a substantial increase of the global coefficient of thermal conduction in comparison with the conventional technology.