It looks like microwave oven technology has found another use – thanks to its ability to heat objects and liquids from the inside outwards. According to Ray Grainger, Senior Technical Director and Chief Technologist at GKN Aerospace, it’s proving to be a very effective way to cure carbon composite structures.  He said recent test results suggest that microwave-curing bonds the fibre layers better than autoclave curing, increasing internal integration and resulting in a stronger product.

Grainger said the microwave process simply requires uncured composite to be placed on a tool or in a mould and sealed in a vacuum before being ‘cooked’ by microwaves – a process which takes around two hours, compared to the 12-hour curing cycles of today’s autoclaves.

A further advantage is that microwaves can be focused to cure selected sections of a structure, enabling large composite structures to be made in several parts. Each component can be made and cured, while the sections where they join can be left uncured. Once these components are assembled however, the joints are cured separately, bonding the elements together as a complete structure. If further tests validate these results, microwave-cured composite will likely become the industry standard.

This is timely technology for GKN Aerospace, as it’s already committed to a £180 million investment to manufacture composite components for the Airbus A350 at two newly acquired facilities near Filton.