
Sandwich structures allow for particularly low weight while maintaining high flexural stiffness. Therefore this design is especially well suited for applications in the interior of airplanes, e.g. panels, side walls, luggage compartments, doors, cabin-separating walls, but also trolleys and cooking modules. Foams made of Ultrason E have been approved for use in airplanes. The material, with its exceptionally high limiting oxygen index of 38 (according to ASTM D 2863), distinguishes itself because it meets the requirements for commercial aircraft with regard to combustibility and heat release ("fire, smoke, toxicity") already without the addition of flame retardants, which means it is intrinsically flame retardant. This is why, for example, the Swedish aircraft supplier Diab uses the BASF polyethersulfone to manufacture foam core materials with different densities.
Sandwich components which can be manufactured thermoplastically in this way have numerous advantages compared to traditional honeycomb structures that are coated with phenolic resins: They can be produced faster in an automated process, they offer various processing options such as thermoforming into different geometries or overmolding for reinforcing ribs and additional functional integration. Thanks to weight-optimized, thermoplastic sandwich structures with additional functions it is possible to realize new lightweight materials for aviation, which have improved characteristics and a significantly reduced cost structure compared to traditional sandwich structures.