Could F1 move to a future beyond carbonfibre?

When Formula 1 announced, in late 2019, its bold ambitions to become carbon net-zero by 2030, the focus was largely on fuels for the race cars. While only representing around 0.7% of the approximately 250,000 tons CO2 equivalent carbon footprint of the championship, the multiplier effect of such technology is enormous.

A much larger proportion of the total footprint lies in transport of both people and equipment around the globe, and this too is high on the agenda – with F1 engaging with the aircraft industry and academia on sustainable aviation fuels (SAF). Many people point out, however, that the cars themselves are built using a large amount of carbonfibre, and ask what effect that has on Formula 1’s carbon neutral ambitions and whether alternatives are being looked at.

It’s perhaps worth reminding ourselves what we mean by carbonfibre, or more accurately, carbonfibre composites. These materials consist of fibres of carbon which are generally woven into a cloth and then impregnated with a resin. In the uncured state the resin binds the fibres together with enough freedom to allow the cloth to be draped in a mould. Structures are normally made up of several plies of cloth and these plies may be separated by a honeycomb stabiliser to give geometric stiffness. Once cured at temperature, the resin hardens and the structure becomes a rigid component.

There are many types of carbonfibre and they may be woven in many different ways, but all fibres used in F1 are of a type known as PAN fibres. These are so called because the precursor that they are made from is a polymer called polyacrylonitrile. This is an organic material which is spun into fibres which are then chemically stabilised. 

At this point the fibres are actually white, but the next process is carbonising which takes place at very high temperature and turns the fibres into tightly bonded carbon crystals. The fibres are then graphitised at around 3,000 degrees centigrade. They are then bundled and finally spun into the specific type of yarn required.

Now carbon exists in many different forms, or what the chemists refer to as allotropes. They range from very soft graphite to extremely hard diamond, both of which are a form of carbon. The carbon in carbonfibre can be tuned to be either very strong or very stiff or, to a certain extent, both. It is this that has made it such an attractive material in applications where extreme properties are needed at a very light weight.

It was first developed for aerospace use by the Royal Aircraft Establishment in Farnborough, England, in the 1960s – but it was motorsport that demonstrated how it could be used in a variety of productionised applications.

Carbonfibre has been used in F1 for decades, as motorsport pioneered its use

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Of course, in the 1960s and even for decades afterwards, few people were thinking about the carbon footprint of the materials they were using, but since this has become a focus research has been undertaken to find replacements for both the fibres and the resins which are also hydrocarbon based.

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The basic principle of obtaining strength and stiffness by combining fibres and resins isn’t new. Fibreglass used in the bodywork of some cars for many years exploits exactly the same principle as does the building of houses by a process known as daub and wattle.

This has been in use since the 12th century in Europe and consists of a lattice – the wattle – made of wood and the daub which is a sticky clay-like substance used in exactly the same way that a room temperature cured resin might be used in modern materials. So the idea of a bio-composite is not really new, but as attention has turned to using bio materials as structural composites, it has emphasised the stunning properties of carbon fibre composites.

A modern bio-composite is made of natural fibres, often flax, although hemp and jute are also used. Being bio-based they are deemed sustainable although, just like first generation bio-fuels, if they use arable land for production they may be in direct competition with the growth of food.

Generally, the production of natural fibres is less energy-intensive than that of synthetic fibres and their ease of biodegradability and high calorific value if incinerated leads to good end-of-life outcomes. Resins too can be bio-based and one bio-based resin which is derived from food waste has a high transition temperature making it suitable for a number of components. 

It’s unlikely that bio-composites will be used for components requiring high strength or high stiffness – such as a monocoque or suspension wishbone – but there are countless applications where the reduced properties will not compromise the design

So what is the greenhouse gas reduction of a natural composite to that of a carbon composite?

Unfortunately, that is rather more difficult to answer than it may seem. The mechanical properties of the natural fibres are not as good as that of carbon, and although the producers of the material have some interesting ways of mitigating this disadvantage a structural component made out of a flax-based composite will be heavier than one made in carbon.

Natural fibres are becoming increasingly common in GT racing

Photo by: JEP / Motorsport Images

While it is claimed that the flax-based composite, weight for weight, can yield a 75% reduction in carbon footprint, this does not take into account the difference in weight of a finished component of comparable strength or stiffness. Neither does it, in a full life cycle assessment, take into account some of the other processes and components used in production.

Insight: Explaining the sustainable answer to using composite parts

While this may sound negative, it is not. It’s unlikely that bio-composites will be used for components requiring high strength or high stiffness – such as a monocoque or suspension wishbone – but there are countless applications where the reduced properties will not compromise the design.

I expect we will see much more of bio-composites in the future and, much as carbonfibre properties have improved over the years through continual development, so too may natural products be enhanced. This will be through process improvements, or maybe even genetic engineering of the plants from which they are derived.

With F1 targeting a carbon-neutral stance, what will the future hold?

Photo by: Steven Tee / Motorsport Images