Fire-resistant composites for engine nacelles

Engineers from Boeing treated fiberglass/polyimide and graphite/polyimide laminiates with various phosphorylated polymers to obtain resins for use in harsh environments.

Design, fabrication, test, and analytical studies have shown that the use of high-stiffness, high-strength composites such as graphite/resin composites can reduce the weight of structural components by as much as 50%, improve structure efficiency, and provide significant benefits in cost and performance.

Accordingly, considerable interest has arisen in the use of graphite composites in both internal and external aircraft applications as well as in engine nacelles. Thus, in external applications such as in fairings, skins, rudders, stabilizers, flaps, and doors, as well as in engine nacelles, the resin should resist burning and also prevent short lengths of the graphite fiber from spreading to others areas. Internal applications would be directed toward cargo compartment liners and passenger compartment floor panels. In either case, low smoke, toxicity, and non-flammability would be an essential criterion.