The automotive industry is making massive strides to become more sustainable. Through the progress the industry is making on electrification, to the novel manufacturing techniques that reduce CO2 emissions – the focus on sustainability is beginning to show promise.
The production of electric vehicles hit 6.6 million in 2021, and the carbon footprint of manufacturing is falling to the lowest it's ever been.
That said, the next step of renewable circularity continues to be hindered by the use of raw materials that cannot, either themselves or post-processing, be recycled. Each of BMW, GM and VW Group all cite the full life-cycle as focus areas of sustainability. This means making components recyclable, long-lasting, and with sustainable raw materials.
The challenge of composites
Designing and manufacturing fully-recyclable automotive designs poses a series of challenges due to the widespread use of plastics and composites – in 2015, 7% of all virgin plastics (made using fossil fuels) were for the automotive industry.
These staple materials have been embedded in vehicles for decades. They are lightweight, thereby improving fuel efficiency, offer safety properties by absorbing kinetic energy, and have innate corrosion resistance.
This separation of plastics from vehicles is important, as many of them are difficult or impossible to recycle. They are often difficult to separate, especially speciality polymers, and thermoset, so cannot be melted down. Resultantly, most automotive plastics end up in landfill.
What’s the most circular solution for polymers and composites?
There is a very clear role for polymers and specialty plastics in the automotive industry. They provide engineers with the optimum mix of performance and light-weightedness for many applications. However, the industry needs to shift away from its unrelenting use of virgin plastics to become more sustainable.
Moving away from these materials requires one of two solutions: 1) an improvement in the recyclability of speciality plastics, or, 2) sourcing a more sustainable, yet suitable, substitute for these components – these could be in the form of light alloys or more recyclable plastics, such as polypropylene (PP).
Polypropylene (PP) is a plastic polymer used by automakers such as SKODA that is able to be reused for circularity. PP is thermoplastic that has reversible chemical bonds, allowing it to be melted and remoulded through a dedicated process.
Reconsidering material selection for sustainability
- Alternative technologies: PEO; light alloys.
- EV reduces design complexity; 20 moving parts vs. 2,000+ – new opportunities for recycling?
In the movement towards circularity, it is clear that replacement materials that are recyclable are required to have sustainable automotive manufacturing. In the context of light metals, Keronite’s industry leading PEO coating method provides designers with a wide range of protective features whilst maintaining complete recyclability.
With PEO, no toxic chemicals, VOCs or strong acids are used during the process. PEO uses 99% distilled water, and because the electrolytic bath is typically a low concentration, chemically benign, aqueous solution, waste liquids can be discharged directly to municipal drains after a slight pH adjustment. During the process, corrosion protection is imparted by changes to the substrate itself, allowing the metal to be recycled at the end of the component’s life cycle.
All things considered, PEO is perhaps the most environmentally friendly method of producing lightweight and long-lived metal alloy components. You can learn more about the environmental credentials of plasma electrolytic oxide (PEO) coatings in our white paper.
