Foam-filled aramid honeycomb sandwich composites with high acoustic insulation properties prepared using a unique thermal expansion molding process

Contemporary advancements in technology and the rapid development of transportation systems have led to the rise of noise pollution as a major environmental issue globally. Foam sandwich composites, distinguished by their lightweight yet robust attributes such as high-strength functionality, effectively combine the superior noise insulation properties of foam structures with the strength inherent in their surface skins. However, traditional foam core materials exhibit limitations in terms of mechanical durability and suboptimal interfacial bonding with the surface skin. This study addressed these shortcomings by employing a novel approach involving a self-developed thermally expandable epoxy resin and an aramid honeycomb composite. These components were co-cured with a fiber prepreg, culminating in the formation of enhanced sandwich composites. The composites fabricated through this method demonstrate an impressive average sound insulation capacity of 70 dB, alongside a significant enhancement in the mechanical properties of the core material, surpassing the performance of standalone foam structures.