GKN Aerospace develops manufacturing processes for complex composite structures

7/17/2006 8:00 AM
Aerospace - Aerostructures

GKN Aerospace is working on the development of new techniques for composite manufacture that will extend the use of composite materials across the airframe and into aero-engines.

Phil Grainger, Technical Director and Chief Technologist at GKN Aerospace explains:

”Composite manufacturing techniques are now mature and have achieved their maximum performance levels. These techniques are intensively manual, and require high levels of manpower at every stage throughout the manufacturing process. However for the composite market to grow, the cost competitiveness of the product must be improved.”

GKN Aerospace is developing vital new manufacturing techniques which will reduce traditional capital investment in plant whilst automating the process to maximise manufacturing performance and drive costs down. These new techniques include developing an 'out of autoclave' manufacturing process and introducing a high speed, highly accurate Automated Tape Layer (ATL).

Grainger continues: “We have recently delivered the first all-composite wing spar for the Airbus A400M military airlifter. These 20m long spars represent the first ever application of carbon composites for a primary structure on a large transport aircraft wing and we are producing them using much of the new manufacturing expertise we have developed”.

'Out of autoclave' curing removes the need for, and intrinsic limitations of, an oven-based manufacturing process. It also brings significant reduction in the capital investment and running costs inherent in using an autoclave. The new GKN Aerospace process is called Resin Film Infusion (RFI) and is now being used in conjunction with self heated tooling on the A380 wing trailing edge manufacture. RFI has been shown to offer a 10% reduction in manufacturing costs, reduced tooling requirements, lower capital investment costs, lower risk in manufacture, potential weight savings as well as a consistently high quality result.

Automated Tape Laying (ATL) machines are showing demonstrable improvements in product quality and consistency particularly in the lay up very large and highly complex components. They also produce substantial reductions in the time required to lay up a composite stack. Typically this can be reduced from a 6 day process to a 48 hour activity, bringing significant cost benefits. ATL is to be employed in the full scale production of the A400M spars.

Looking to the future, GKN Aerospace last year opened its Composite Research Centre (CRC). The CRC is already involved in at least 5 aerospace related research programmes and is investigating areas including acoustic technologies, the application of composites into aero-engines and the further development of manufacturing processes which will enable large, highly complex, and curved assemblies to be produced swiftly, to high levels of tolerance, with great consistency.

Grainger concludes “Our goal is to do all this at a cost that is acceptable to the highly competitive aerospace marketplace today”.