Characterization and Modeling of Cure-Induced Thermo Mechanical Properties and Chemical Shrinkage of Epoxy Resins

Epoxy resins are widely used in molding electrical insulators and electronic components due to their superior dielectric properties and mechanical strength. However, due to poor process control along with the complex geometry of their components, parts can entail air pockets, cracks, or deformations driven by residual stresses. To address these challenges, this research uses the Computational Fluid Dynamics (CFD) software Autodesk Moldflow Synergy 2023 to visualize epoxy resin flow behavior and predict the curing behavior as it flows through the mold using respective models. When simulating the mold-filling behavior, comprehensive thermo-mechanical data are required for both uncured and cured states of cycloaliphatic epoxy resins. Therefore, it was crucial to thoroughly characterize the material to obtain precise material parameters for using them in simulations, as these parameters play a vital role in the accuracy of the simulations. Python-based formulations of the Prout-Tompkins cure kinetic and Cross-Castro-Macosko viscosity models are used to comprehensively analyze the flow front and curing behavior during an Automatic Pressure Gelation (APG) process. This research provides valuable insights into the behavior of epoxy resin when molded in complex scenarios. It enables the design of optimized molds while allowing for fast and efficient evaluation and optimization of process parameters, ultimately reducing high rejection rates as safety critical parts, like insulators, need to be flawless.