Mold heating is an important key factor for the mold cycle which affects the quality of the molded product. The involved molding processes regards polymers foaming, plastics injection, or resin-curing with composites. While the manufacturing cycle of plastics injection molding requires a heating/cooling system, other processes do not require the cooling phase. Polymers foaming and resin-curing require specific values of temperature to provide full chemical reactions and a good product quality on the surface. Induction heating systems are suitable for such applications; however, many industrial cases require customized solutions to support the molding cycle of different parts. A temperature control is always mandatory to reduce the energy cost and increase the heating efficiency. This paper studies a molds temperature control applied in the polyurethane foaming of footwear soles. The proposed induction heating system and its control have been studied using the Hardware-In-the-Loop simulations. Due to a high mold thermal inertia, which increases the mold temperature even if the control system turns off the thermal power, tailored controllers have been analyzed to achieve the desired temperature set-point. The thermal model of the foaming mold and the induction heating system have been modelled and developed in the MATLAB/Simulink® framework. An ATMEGA processor was used to implement and test a discrete PID controller while Simulink induction-heating system model was running, creating an Hardware-In-The-loop platform.
Prist, M., Pallotta, E., Cicconi, P., Monteriu, A., Germani, M., & Longhi, S. (2018). Induction Mold Heating: Modelling and Hardware-in-the-Loop Simulation for Temperature Control. In Proceedings - 2018 IEEE International Conference on Environment and Electrical Engineering and 2018 IEEE Industrial and Commercial Power Systems Europe, EEEIC/I and CPS Europe 2018 (pp.1-6). Institute of Electrical and Electronics Engineers Inc. [10.1109/EEEIC.2018.8493863].