Experimental validation of effective glass transition temperature‐based model for predicting skin thickness in solid‐state microcellular foams

Abstract The solid‐state foaming process produces microcellular foams with an outer layer of solid skin that encapsulates the cellular core. In this article, we implement a 1D model to predict the thickness of the solid skin based on the effective T g of the polymer‐gas system for a given foaming temperature. The model is based on the understanding that bubbles nucleate when the foaming temperature exceeds the effective T g during the foaming process. The model was validated with experimental results on the PC‐CO 2 system, which showed that skin thickness decreases with increased foaming temperature. We also developed a linear correlation to accurately predict effective T g at different CO 2 concentrations. The article also explores the model sensitivity to the key input parameters related to gas diffusion. Highlights Linear correlation to accurately predict effective T g profiles in PC‐CO 2 system. Increasing foaming temperature decreases skin thickness. Model is sensitive to the input parameters related to gas diffusion.