Eco-sustainable sandwich panels: Influence of process parameters on adhesion and mechanical performance

In recent years, there has been a growing interest in recyclable and eco-friendly materials, driven by the need to develop components with complex geometries, variable thicknesses, and large dimensions, particularly in sectors such as building and automotive. EcoSustainable Sandwich Panels (ESSP), which combine lightweight cores with thermoplastic natural fiber-based composites, offer a promising solution to these demands by providing a balance between mechanical performance and sustainability. Despite their potential, ESSPs remain underexplored, with limited knowledge regarding the key factors necessary for their manufacturing. The low Technology Readiness Level (TRL) of these materials, along with challenges in ensuring reliable performance, particularly in terms of adhesion between skins and cores, hinders their broader industrial adoption. This study investigates the forming of Ecosustainable Sandwich Panels (ESSP) consisting of an aluminum honeycomb core and skins made from flax fiber prepreg with a polypropylene matrix, manufactured by hot press molding. The aim is to evaluate the influence of process parameters on the adhesion between skins and core, which is critical for the mechanical performance of the panel. For this purpose, preliminary numerical analyses and destructive testing were made, and the results provide valuable insights for optimizing the production process of eco-sustainable sandwich panels and their potential industrial applications.