GKN Aerospace asked Umeco to design and manufacture low weight, low cost mandrels exhibiting high stiffness and excellent geometric accuracy.

The mandrels that Umeco designed and manufactured consisted of machined foam cores over-laminated with Umeco’s LTM®217 epoxy tooling resin system combined with woven carbon fibre and ultra-high modulus unidirectional carbon fibres.

The mandrels were then machined in their assembled state to the final spar dimensions, within the specified ±0.25 mm tolerance.

The suite of tooling mandrels (measuring 13.7, 12 and 11.9 m) provide GKN Aerospace with a number of benefits. Firstly, the designs incorporate a vacuum system to facilitate air extraction at the debulking stage from a single point at the end of each mandrel. This leaves the full length of the mandrel surface uncluttered and accessible for the AFP operation, while simplifying the vacuum bagging operation.

Secondly, initially designed specifically for current Airbus A350 XWB wing construction, all four mandrels can be re-machined and re-laminated to implement quickly and cost-efficiently geometry changes.

“We were pleased by the prospect of working with GKN Aerospace and applying our tooling expertise and prepregs on a project of this magnitude," says Liam Moloney, Umeco Engineering Manager – Tooling.

"These tooling mandrels set a new challenge for us, but we rose to the occasion and succeeded, both for us and also for our customer. The tooling mandrels are now being used to manufacture wing spars for aircraft which are setting the standards in aviation."