The aerospace composite market will pocket $50 billion annually by 2018, up from $10 billion per year currently, according to a recent projection by InterFlight Global, an aerospace consulting firm based in Miami. Driving the upward trend are evolving products and innovative companies.
Dutch-based Fokker Aerostructures, TenCate Aerospace Composites and KVE Composites Group, and German-based Ticona are among those companies pushing the envelope. Gulfstream approached Fokker, with whom it had a long-term relationship, for ways to improve the structures on its newest aircraft, the Gulfstream G650. Fokker’s solution: a thermoplastic composite rudder and elevator. The new parts would meet Gulfstream’s desire for lighter weight, lower cost. According to Art Offringa, Fokker’s director of R&D, the company felt they could provide a product with the most improved cost-to-weight ratio by focusing on the wing.
As Fokker’s R&D evolved, it turned from a polyphenylene sulfide (PPS) composite bonded and riveted in place to an induction welding process. This process, used to create the elevator and rudder, requires PPS and carbon fabric. The film is heated and squeezed into the carbon fabric, after which the sheet is heated and stamped with match metal welding tools. Then the skin and ribs are assembled in place using precision tooling. The process results in no dimples and spot melting at the interface between layers.
This so-called blind process (contributed by KVE) cuts the manufacturing time in half and is now FAA certified. “This is a big step forward for thermoplastic composites,” says Mike Favaloro, technical marketing manager for Ticona. “The elevator and the rudder, also known as the tail portion of the plane used to control direction and stability, are critical parts on the exterior plane. It’s the first time those parts have been manufactured from thermoplastic composites. Before this, the parts were been made by thermosets because they’ve been proven on the military and commercial levels for the past 40 years, but thermoplastics are a newer technology. Until now it’s been limited to usage in minor parts such as the nose that you don’t want to lose, but aren’t critical to overall plane operation.”