Modelling and Analysis of the Cooling Process in Post-Hot Flat-Pressed Wood-Plastic Composites

This study aimed to develop a mathematical model describing the thermal dissipation kinetics during the post-processing cooling phase of flat-pressed wood–polymer composites (FPWPC). The model elucidates the relationship between the composite's cooling time and the spatiotemporal temperature distribution across its thickness, as influenced by wood particle content, initial surface temperature, and bulk density. Analysis of the thermal profile in the core layer revealed three distinct phases: an initial temperature increase, a thermal peak, and a convective cooling phase. The results demonstrate that both the wood particle content and the initial surface temperature significantly affect the thermal dissipation rate. Higher initial surface temperatures (e.g., 200 °C) led to an initially accelerated cooling rate, followed by a deceleration phase. Composites with higher wood particle content (60%) exhibited slower cooling rates, which is attributed to the lower thermal conductivity of wood relative to the thermoplastic polymer matrix, resulting in greater thermal retention. Bulk density was also found to play a critical role in thermal management by influencing the composite’s specific heat capacity, thermal conductivity, and convective heat transfer efficiency. The proposed mathematical model offers potential for optimizing FPWPC manufacturing processes by enabling more precise control over cooling dynamics.