Experimental Measurement and Multivariate Modeling of Thermal Contact Resistance Under Injection Molding Conditions

ABSTRACT A novel method was developed to characterize thermal contact resistance (TCR) at the polymer/mold interface under injection molding conditions. The study emphasizes the design and validation of an experimental setup that accounts for variations in material type, surface finish, and process conditions. The goal is to establish a model for computing variable TCR values, moving beyond the conventional assumption of constant resistance. This advancement aims to improve the accuracy of temperature distribution predictions in injection molding simulations, which are critical for modeling polymer flow, shrinkage, and warpage. TCR measurements were performed using a specialized compression molding setup comprising two stack configurations with differing numbers of identical mold‐polymer interfaces. Comparing the heat transfer behavior between the two stacks enables a precise calculation of TCR. Statistical techniques, including multivariate regression and principal component analysis, identified polymer temperature as the most influential factor affecting TCR. Measured values ranged from 0.0003 to 0.0015 m 2 ·K/W under the tested conditions. The thermal conductivity of the mold metal exhibited a moderate influence, while surface roughness, polymer thermal conductivity, and part thickness had minimal effects on thermal performance.