PHOTO: The structural parts are subjected to extreme performance testing for use in jetliners and hence have to be made to the highest standards

AEROSUD, an aero-mechanical component manufacturer and systems developer in Centurion, is achieving success with the production of structural components for airliners using continuous fibre reinforced thermoplastics (CFRTP) technology.

It has got initial contracts from USA-based aeronautics supplier Spirit Aerostructures and is currently producing various structural brackets and clips that are used to connect the aircraft skin panels to the airframe of the new Airbus A350. The parts are being used by aircraft manufacturers such as Airbus and are subjected to extremely stringent testing, so it’s a feather in Aerosud’s cap that it has succeeded in getting repeat orders from the initial production runs.

The components, manufactured from sheet produced from PEEK (polyether ether ketone) or with continuous carbon fibre strand, are replacing aluminium parts. The PEEK parts achieve high strength, low weight as well as temperature and corrosion resistance, which is necessary for aircraft parts.

The technology for the CFRTP process was developed at the Delft University of Technology in the Netherlands. Dr Kjelt van Rijswijk, who studied composites at this university and who completed part of his degree at Stellenbosch University, remained in South Africa to head up Aerosud’s composites research division. He has been instrumental in tutoring the skills and systems development for the process at the Centurion company, working closely together with the CFRTP project team.

The reinforced sheet is imported from Toho Tenax in Germany. Water jet cutting is used to cut out the initial shapes, which are then formed in a heated hydraulic moulding press using infrared heaters at 425°C. This is the stage of the process where Aerosud is excelling. After forming, the clips are trimmed and inspected for internal porosity and defects via ultrasonic testing, before the approved components are flown out to America.

Each aircraft contains several thousand clips, which means that traditional lay-up composite production processing with long curing times is not suitable here. CFRTP uses a rapid heating and cooling cycle to produce composite parts in a matter of minutes, which allows Aerosud to produce 2000 components per month on a single hydraulic press.

Aerosud’s ability to create the complete production cell for these parts, including the intensive testing required, has also been utilised for the manufacture of CFRTP interior panels for the Airbus A400M, for which Aerosud developed the world’s largest CFRTP press in-house. Aerosud will continue to further develop its CFRTP capability to make larger and more complex parts or even to produce CFRTP assemblies by welding individual parts together.

www.aerosud.co.za