WHY THE DUTCH GOT RID OF THEIR OVEN

Foam-cored carbonfibre components, with bonded fibre either side of a piece of filler, aren’t unusual. But Donkervoort has invented and patented a new way of constructing it, called Ex-core.

Traditionally, you make the carbonfibre skins, then just bond some foam in the middle of them – as with foam-cored aluminium.

By the Ex-core method, outer shells of carbonfibre impregnated with resin are laid into moulds that have built-in heater elements, then the appropriate amount of expanding foam is placed inside them and the pieces are pushed together at pressures of up to 20bar. The elements heat both the outer fibres and inner foam (which expands to fill the gaps) more precisely than an autoclave (basically an oven), so the foam fills every cavity. Because the resin in the foam and carbonfibre matting are heated simultaneously, they bond better to become one.

The result is a brilliantly strong, light material that can accept complex curves and needs less energy and time to cure than in an autoclave. The process was designed for the D8, but Donkervoort has since found demand for yachts, bicycles and other specialist sports. Last month, it bagged its first F1 client.