Farnborough News: NRC Aerospace Transfers Breakthrough Composites Manufacturing Process to Delastek

Farnborough, July 17, 2006 – A successful collaboration between the National Research Council Institute for Aerospace Research (NRC Aerospace) and Bell Helicopter Textron Canada Ltd. (BHTCL) has resulted in a Canadian breakthrough in the manufacture of aerospace structures using composite materials — and a new business line for a Quebec company.

NRC Aerospace first developed expertise in manufacturing composite rib chords using resin transfer moulding (RTM), as well as an adhesive process to bond the rib chords to BHTCL-manufactured wing skins, then used this expertise to produce the most complex composite aerospace structure ever built in Canada, an all-composite wingbox for a next-generation tilt rotor aircraft. The RTM technology was subsequently transferred to Delastek Inc., a company based in Grand-Mère, Québec, establishing it as a supplier of aerospace-grade RTM parts.

Dr. Robert Fews, Research Director at BHTCL, stated, "This project has put Canada on the map in terms of composite technology demonstration…This proven technical capability, together with the outstanding working relationship experienced in the execution of this program, bodes well for future collaborative programs."

The project, initiated in April 2004, grew out of BHTCL's desire to obtain the composite parts for its products from Canadian suppliers. To carry it out, two teams at NRC Aerospace worked together to develop the technology in-house.

One team, at the Institute's Montreal-based Aerospace Manufacturing Technology Centre, manufactured composite rib chords for the wingbox using resin transfer moulding (RTM), a process that involves injecting resin into a mould containing a woven fabric then heating the contents to cure the resin. The process used a modular mould concept to fabricate two different ribs using removable inserts within the same pressure cavity. This reduced overall costs, as did increasing the temperature inside the mould to do the curing, rather than using an autoclave.

The other team, at the NRC Aerospace Structures and Materials Performance Laboratory in Ottawa, constructed a bonding fixture and developed a novel process to bond the ribs to the wing skins. The adhesive bonding approach was unique in that it included cure monitoring and process control to ensure even heating along the entire rib. It also permitted the process to be halted, and corrected, at any time during the 20-minute processing window if anything went wrong.

The rib chords are the first known primary composite aircraft structure (PCAS) produced in Canada using RTM, while the rib-wing joints are believed to be Canada's first instance of PCAS bonding.

The completed wing skins were delivered to BHTCL in the summer of 2005 and the RTM technology subsequently transferred to Delastek. The company, which initially knew nothing about the technology, did the machining, made the rib mould, and participated in the production process. The effort paid off as Delastek has obtained a new contract with Bell to make another RTM part using the modular mould. NRC Aerospace will again assist them in developing the process.

Delastek Inc. is a company located in Grand-Mère, Québec that specializes in the manufacture of parts made of high-technology composite and plastic materials mainly for the automotive and aeronautics industries. It serves large corporations such as Bombardier Aéronautique, Prevost Car, BRP, Bell Helicopter, and Pratt & Whitney.