Geometric parameter optimization of mold heating channels for rapid heat cycle molding

In this work, mold for producing LCD panels with Rapid Heat Cycle Molding (RHCM) process was studied. The thermal control system of the mold allows the improvement of the process productivity and the product quality. Hence, our objective was to minimize the heating time and to homogenize the temperature at the mold cavity surface. For this purpose, we propose in the present study, a geometric parameter optimization of the conformal thermal control system such as heating/cooling channel diameters, heating/cooling channel spacing and heating/cooling channel distance to the cavity surface. Thus, a 3D numerical model was developed using the finite volume method. The results show that the thermal regulation system which assures minimum heating time does not necessarily achieves the best temperature distribution throughout the product. In fact, to ensure the homogeneous temperature distribution in the surface of the mold cavity, it was found advantageous to reduce the diameter of the heating channels, removing them from the cavity surface and spacing them. On the other hand, it was demonstrated that these actions cause a loss in productivity.