A comprehensive review of injection mold cooling by using conformal cooling channels and thermally enhanced molds

Conformal cooling channels (CCCs) are employed to improve the cooling rate due to the equal distance from the mold surface. CCCs play a key role in mold injection productivity by enhancing heat transfer between the CCs and mold surface, which leads to shorter cooling time. As the cooling stage of the mold injection highly influences the quality and efficiency of production, the design of cooling channels (CCs) and thermally enhanced molds has recently received great attention. Furthermore, the shape and design of CCCs have particularly been studied extensively since these parameters indicate promising effects on the cooling performance. Moreover, new designs and novel material compositions are being proposed in order to improve the heat removal in injection molds. This paper reviews the various and significant types of the CCCs by classifying them into four major groups. An overview of advancements of CCCs and thermally enhanced molds are provided which considers simulations and numerical and experimental studies generally. Details are also given for new proposed designs that utilize different algorithms, optimization process, fabrication procedures, and optimization parameters in CCC design which is summarized. Generally speaking, studies show that conventional straight drilled CCs are expected to be substituted by CCCs due to their promising performance in diminishing the cycle time and shape deviations of forming plastic. The most common results of summarized literature demonstrate a shorter cycle time in CCC utilization in comparison to the conventional CCs. This is because injection molding process cycle time significantly relies on molded part cooling time. In addition, warpage and inconsistent volume shrinkage of the plastic parts is reduced considerably. Varied manufacturing methods are applied in CCC fabrication, with additive manufacturing being the dominant fabrication technique. Ultimately, the review concluded that shape, temperature distribution, and pressure drop are the key parameters for CCCs in mold injection.