Carbon Lighter: under the skin of the BAC Mono R

“Traditionally there are three different layers of carbon in a carbonfibre layup. There’s the face ply – because a lot of our carbon is visual – then you have a bulk ply and another face ply. A lot of our parts are two-sided, like the floor, which curves up round the side, so you don’t just have an ‘A’ and a ‘B’ side, you have two ‘A’ sides.”

The addition of graphene allows BAC to either take a layer of composite out (such as reducing the thickness of the bulk ply) or change the grade of the material while still achieving the structural target but saving weight and cost.

“We targeted four different parts initially because they all presented different challenges,” says Briggs. “First there’s the main body [the painted upper surface], a huge part, so in that respect there was a magnitude challenge. Then we looked at the rear diffuser, which is combined with the rear wheel arches. That gave us a geometric challenge, because it’s a complex part to mould. We also picked the side pod, which is close to the exhaust, so there was a thermal challenge, and also the core panel, which is one of the lower panels, because of the harshness of the environment, stone chipping and so on.”

It became clear early on that 10-20% weight savings would be possible on each component. “This project is of benefit to BAC, of course, but the wider benefit is understanding graphene and what it could do in higher volume in the automotive industry and across the other sectors,” says Briggs.

Graphene is also used in the carbonfibre tooling moulds in which the components are formed. Because it makes the carbonfibre a better conductor of heat, the tool can be heated more quickly and cooled more quickly for curing, reducing the cycle time and saving energy. “If we’re reducing the cycle time and using less material to make the mould and the component, the cost comes down,” explains Briggs. This, together with the shorter running time of the autoclave, adds up to a saving in CO2 emissions – the main point of the original project funding.

The wider implications for all uses of carbonfibre composite are more significant. In this sense, the Mono R is a rolling laboratory for the innovation of lighter, more cost-effective materials.

Briggs is confident that the same technology is now ready to be adopted by the bigger niche car makers should they wish, but could it prompt increased use in mainstream cars? “I see the niche vehicle sector as an absolute catalyst for proving new technology at a proof-of-concept level and then taking it on to production readiness, which is exactly the two steps we have been through in this case,” he says. “I know what we’ve learned from this project and what the suppliers have learned.

They already have major manufacturers as customers, so there’s already a potential customer base. For us, as a first mover in the automotive space, it helps showcase the fact that we are a design- and innovation-led business.”