Predicting the mold-glass interface adhesion in thermal molding

Abstract

Adhesion between a mold and a glass workpiece during demolding remains a significant challenge in precision glass molding, limiting process efficiency and product quality. Although previous studies have examined factors influencing adhesion, they are limited and predominantly qualitative, lacking a reliable framework to predict adhesion force across different mold-glass systems. This study develops a new dimensionless formulation incorporating twelve key variables to quantify the relationship between molding factors and adhesion force. The model is established through molding experiments on d-FK95 glass with three distinct mold materials, complemented by molecular dynamics simulations. The study evaluates contributions from molding parameters, glass Young's modulus, viscosity, and thermodynamic adhesion work, with atomistic interaction energy analyses at varied molding temperatures. DLC molds demonstrate superior anti-adhesion performance compared to WC and AlCrN due to their lower surface energy and amorphous structure. The model identifies molding temperature as the dominant factor, with an exponent of 42.85, followed by demolding temperature and molding force. The accuracy and applicability of the model are validated through a comparison between experimental data and fitted values for two different mold materials. The results show that the proposed model demonstrates high applicability, underscoring the critical role of precise molding parameter control in minimizing adhesion-induced defects.