Design for additive manufacturing: Thermoforming mold optimization via conformal cooling channel technology

The cooling system of thermoplastic mold plays a critical role during the production process because it not only affects part quality but also its cycle time. Traditionally, due to the limitations of conventional drilling methods, the cooling system of the thermoforming mold usually consists of simple paralleled straight channels that results in a lack of performance to cool complex shapes. Nowadays thanks to the evolution of additive manufacturing technique (AM) characterized by an increase of shape complexity it is possible to design a complex cooling system conformal to the mold geometry (conformal cooling). However conformal cooling respect to others AM design improvements, as topology optimization, is still under development and specific rules that define how to better design cooling channels still do not exist. In this paper, to enlarge the knowledge about this methodology, the authors simulated the performance of three different conformal geometries (serpentine, rectangular and tank) and compared the results with the traditional geometry in terms of cooling performance. Results highlight how serpentine geometry is able to improve process performance imposing a cooling curve characterized by a higher slope respect to the traditional shape.