Thermoplastic composite sandwich panels with recycled PET foam core: A manufacturing process assessment

This study attempts to modify two distinct lamination processes of double-belt and compression molding to produce environmentally sustainable full thermoplastic sandwich panels. A precise assessment of fabrication parameters was conducted to ensure the quality of sandwich panels made of glass/Polypropylene composite skin and 100% recycled PET foam core sourced from consumer waste bottles. Evaluations of the skin-to-core adhesion properties revealed that the PET foam density in conjunction with the fabrication approach can affect the layers' bonding. The formation of satisfactory interlayer connection under controlled process parameters was confirmed by Peel-off and flatwise tensile test results. Moreover, complementary three-point bending analyses highlighted deviations in panel performance. Panels manufactured by the compression molding method exhibited superior load-bearing capacity compared to those made via a double-belt machine. These observations are attributed to the inherent nature of the lamination procedures, taking single or multiple thermal treatment phases to fabricate the sandwich panels. Finally, the findings suggest that despite potential slight quality degradation, the production continuity capability of the double-belt method makes it a viable option for meeting industry requirements.