Multi-objective Optimization of Conformal Cooling Channel Design in Injection Molds Using Taguchi Grey Relational analysis

Abstract

The widespread use and demand for plastic products worldwide have caused manufacturers to covet high productivity and product quality. Most plastic products are produced using the injection molding technique. This technique is characterized by long cooling times, which affect the production cycle and product quality. Literature reveals that cooling in injection molding can be significantly affected by the design of the cooling channels. This study is, therefore focused on design optimization of circular cross-section conformal cooling channels. The Taguchi design of experiments approach was adopted in this study. The key variables of conformal cooling channels that were studied involved diameters, depths, and pitches. Solidworks® was used for 3D design, and for numerical simulation to determine the cooling time, volumetric shrinkage, warpage, and sink marks. Multi-response optimization was then conducted using the Taguchi-Grey Relational Analysis technique. Results show that the optimal cooling channel design has a minimum; diameter of 8 mm, depth of 12 mm and pitch of 16 mm. Additionally, Analysis of Variance (ANOVA) revealed that the diameter is the significant cooling channel design parameter that contributes to all the responses concurrently with the largest percentage of 80.26%. Comparing the conformal with straight cooling channel designs, superior performance was noted for the former against the later with optimal design recording an improvement of 29.35%, 5.99%, 19.77%, and 38.85% in the cooling time, volumetric shrinkage, warpage, and depth of sink marks respectively.