Simulation study of engineered Integral-Layer with Solid-Skin structure in Microcellular Polystyrene Foam using Superheat-Induced-Foaming method

Abstract Microcellular plastic foam can be formed by the so-called superheat-induced-foaming method, which known as solid-state foaming process. This process involves the dissolution of the blowing agent (CO 2 ) in polystyrene and foaming the gas-laden polystyrene by induction the superheat on it. This process utilizes the effect of plasticization due to dissolved blowing agent in polystyrene matrices. An interval time which desorption of CO 2 occurs, definitely after dissolution CO 2 in polystyrene prior the foaming process, would make it is possible to develop the integral layer which consists of transition-cellular-core and solid-skin layer by manipulating the desorption time. In the present study, the solid-skin and integral-core-layer formation is simulated by considering the heat and mass transfer model to predict the solid-skin thickness and classical nucleation theory to predict the amount of cell density. It is concluded that with an increase of desorption time, the solid-skin is thicker, and the cell density is lower, compared with the lower desorption time, thinner solid-skin is obtained. Whereas, an increase in foaming temperature, thinner solid-skin with higher cell density is predicted contrary with lower foaming temperature. Additionally, in this study, the predicted cell nucleation is validated to the experimental results with sum-squared-error about 7.248.