Conformal mold heating and cooling using a CNT film heater and 3D-printed cellular structures

To enhance the quality of parts and decrease cycle time in injection molding, appropriate control of mold temperature is required. To achieve these objectives, a novel mold design has been suggested that has conformal mold heating and cooling capabilities using carbon nanotube (CNT) heater. The CNT heater was installed in a curved mold to obtain conformal mold heating capability. An additively manufactured microcellular structure was placed underneath the CNT film heater to improve heating efficiency by playing as a thermal insulator. Additionally, the microcellular structure serves as a heat exchanger during conformal and rapid mold cooling by circulating a coolant through its porous structure. By using both the CNT film heater and microcellular metamaterial, the mold temperature changes uniformly during the thermal cycle, which is an improvement over previous mold heating methods. The proposed technology can improve the part quality as well as productivity of molding processes.