Modeling the effect of scale deposition on heat transfer in injection molding

The advent of additive manufacturing technologies has revolutionized the design and application of injection molds with conformal cooling systems. These mold inserts, manufactured directly from metal powder, feature complex geometries that align with the part contours, enabling more efficient and uniform heat extraction than traditional cooling methods. However, over time, even the most efficient cooling circuits degrade due to corrosion, limescale, and other deposition on the cooling channel walls, significantly decreasing heat transfer. We developed finite element models to simulate various deposition scenarios to address the complexity of modeling these depositions and their impact on heat transfer. Our study evaluates the thermal conductivity and thickness of deposit layers in conventional and conformal cooling channels. The resulting universal model accurately predicts the cooling efficiency of injection molds produced of various mold material, considering arbitrary deposition characteristics, e.g. limescale and corrosion. This model makes optimizing cooling systems for injection molds easier, thus providing crucial information on the time limit of the predictive maintenance and the mold performance change.