The aerospace sector has always been at the forefront of technological change, and now it is spearheading a change that worries many: a shift towards automated manufacturing. But will this, as many fear, signal a reduction in jobs, or is it an opportunity to redefine manufacturing skills for the new century?
At Airbus’s site in Hamburg, one of the most striking manifestations of automated manufacturing is hard at work. With its latest aircraft range, the A350, having a much larger proportion of composites in its structure than older aircraft, new manufacturing technologies are a crucial part of the Airbus strategy. The aircraft wings, for example, are wholly composite, and the company has switched from manual to fully automated production for the wing components.
Whereas at the outset of A350 production, the wing covers – the skin that sits on top of the wings’ inner structure – was laid up by hand, the company has recently started using automated fibre placement to build the wing covers. It’s a striking sight. Like most large composite parts, the wing cover is made up of a series of layers of tapes; carbon fibres arranged side by side and impregnated with resin, with each strip about 5cm wide.
These are unrolled from large spools into what is referred to as the tool – essentially a negative impression in metal of the final piece. The strips are laid side by side from the roots of the wing to the tip until the tool is completely covered, then the next layer goes from the leading to trailing edge of the wing, and then a layer at 45° to both.
The machine that does this dangles from a moving gantry that sits above the tool. Tracking backwards and forwards and side to side, over the 32m length and 6m width of the tool, the device resembles a moving sewing machine. Its sides are studded with spindles that hold the reels of composite tape, which passes over a heated plate to partially melt the resin component of the composite and make it sticky so it binds onto the other layers. The first layer is applied onto a layer of conductive copper mesh that helps to protect against lightning strikes.
Some human involvement is still needed. Inevitably, some tapes do not stick down properly, and a technician needs to ensure any loose pieces are pressed down by hand. But the machines reduce variability, work faster and complete more parts than the labour-intensive alternative. Completed wing covers are cured inside an enormous autoclave, which is capable of holding several wing covers at once on racks; Airbus is planning to add a second autoclave of the same size as part of its strategy to increase production rates.
In the UK, a similar process is being undertaken at GKN, in Severnside near Bristol. Another section of the A330 wing, the rear spar, is also being made using automated fibre placement. The rear spar is a tray-shaped component, running from root to tip of the wing, and forms part of the fixed trailing edge, to which several moving components, such as the flaps that slide out on take-off and landing, and the main landing gear, are attached.
Read the full article here: https://www.theengineer.co.uk/automating-aerospace-manufacturing/