Aircraft

GKN Aerospace has optimised automated technology to speed up carbonfibre tape lay-up on the Airbus Military A400M primary wing spar it makes by up to 40 times compared with hand methods.

According to chief technologist Phil Grainger, automated tape lay-up (ATL) machinery developed by GKN can lay composite tapes 150mm (5.9in) or 300mm wide at the rate of around 40lb (18.2kg) per hour compared to hand lay-up at 1-3lb per hour.

The company is also looking at the use of a complementary technique - automated fibre placement (AFP) - to speed the production of more complex shapes.

While ATL is excellent in production of large, reasonably flat structures, it can cause composite fibre buckling in more highly shaped components.

AFP is slower in laying up large flat surfaces, but is accurate over far more extreme curves and changes in direction owing to the AFP machine's use of narrower, independently controlled separate tapes to make up overall tape width.

AFP may be useful for making more complex wing spar features, and GKN sees it as having great potential in making hybrid engine components and engine acoustic liners.

Grainger says automation is not only fast. The 14m (45.9ft) wing spars the company makes now are accurate to within 0.5mm, compared with about 300mm for the corresponding metal components they are replacing.

© Airbus Military

Automated production is also increasing material quality, says Grainger - while for most products 4% "void" is acceptable, GKN is achieving 1-1.5%.

Ultimately, he says, the increases in quality and consistency being achieved through automation are moving GKN towards a time when it will not be necessary to inspect every component post-production.