Conformal cooling channels with composite layers

Abstract

ABSTRACT Conformal cooling channels (CCCs) are a cooling method used in injection molding. According to the literature review, CCCs can reduce cooling time by 2%–70%, with the average reduction being 30%, and they can improve warpage by 5%–90%, with the average improvement being 37%. But the present study found that previous research has ignored the effect of the solidified skin layer in CCCs. This study posits that during the design of cooling channel positions, the plastic solidified layer exhibits distinct thermal properties. Heat transfer involves conduction thermal resistance, which affects the effectiveness of heat conduction. Ignoring the solidified layer can lead to inaccurate predictions of cooling channel positions. Accordingly, this study developed a novel calculation formula for determining the cooling channel positions while considering the existence of the solidified layer, leveraging the concept of steady one-dimensional conduction in composite layers. The results of this study indicated that in the uniform-thickness scenarios, optimal cooling efficiency and quality were obtained when the thickness of the solidified layer was 0.10 mm. However, in the variable-thickness scenario, the cooling efficiency decreased by approximately 2%. Regarding quality, higher deformation control in three dimensions but poorer warpage control in the z-dimension was observed.