GKN turns to automation for aerospace composites

The company’s aerospace division said it believed that with ever more of the airframe content manufactured from composite materials (some 60% on the latest passenger aircraft) and the aero-engines market now looking more closely at the benefits of using composites, it needed to develop and evolve automated processes to allow complex structures, whether flat or curved, for airframe or engine, to be produced swiftly, to a consistent standard, and cost effectively. Existing products continued to be produced using traditional processes as the cost of the re-certification of the part can be prohibitive, it said. However, new programmes such as the contract for the A400M primary wing spar, had already offered GKN Aerospace an opportunity to introduce some automated manufacturing processes. For the A400M wing spar - the largest all-composite wing spar ever produced - the company has employed Automated Tape Lay-up (ATL) equipment for the first time in the manufacture of a primary component. ATL can lay composite tapes 150mm or 300mm wide at rates of around 40lb of tape an hour. This compares with hand lay-up rates of between 1 and 3 lb/hr. Although the ATL process has required significant optimisation by GKN Aerospace as the spars are complex forms that must be manufactured to an extremely high quality, ATL has proved very successful in production, increasing tape deposition rates by a factor of 40. GKN Aerospace is now exploring the application of Automated Fibre Placement (AFP) - a complementary process to ATL which, although excellent in the production of large, reasonably flat structures, can cause composite fibre buckling in more highly shaped components. Frank Bamford (pictured), Senior Vice President of Business development and Strategy at GKN Aerospace said: "As the leading independent supplier of composite structures for aviation, the development of effective automated processes is, of course, a key focus for us. We are examining all our accepted manufacturing practices and exploring many innovative ideas and in future we expect to employ a range of automated processes that will support our highly skilled workforce in producing complex parts far more swiftly, in greater quantity and more economically than is possible today."