Review of balsa core sandwich composite structures

Renewed efforts towards greater use of environmentally sustainable materials have created new opportunities for balsa wood (Ochroma pyramidale) to replace non-renewable, petroleum-based cores such as polymer foams in a broad range of sandwich structures. This paper reviews published research into the applications, manufacturing, microstructure, mechanical properties and in-service performance of sandwich structures with balsa wood cores. The benefits of balsa wood in sandwich structure construction are reviewed, including environmental sustainability, low raw material cost, excellent specific mechanical properties, and thermal insulation properties. The potential challenges of balsa cores in sandwich structures are also evaluated, including potential global supply chain issues, limited applicability of part processing techniques, impact, blast and fire performance, as well as water durability. Published research into the underlying properties and mechanisms responsible for the benefits and limitations of balsa core sandwich structures are reviewed. Topics for further research to advance the characterisation and applications of balsa structural sandwich materials are also discussed.