A research initiative coordinated by Sweden’s Royal Institute of Technology (KTH), alongside Volvo Cars, Karolinska Institute and Scania, including tyre rubber compounds and bitumen-based road materials supplier Nynas, has been set up to better understand the formation, characteristics and environmental impact of wear particles generated at the tyre-road interface.
As the transition to electric vehicles accelerates, particle emissions from internal combustion engines are beginning to decline. In their place, non-exhaust emissions – particularly Tyre and Road Wear Particles (TRWP) – are attracting more attention.
Formed through the frictional interaction between vehicle tyres and road surfaces, these microscopic particles are now being addressed in the upcoming Euro 7 emissions standard. While TRWP are not yet fully regulated, key players in the automotive and infrastructure sectors are mobilising to get ahead of the curve.
Despite the importance of TRWP in the overall emissions picture, scientific knowledge has remained limited – particularly regarding how different materials contribute to wear mechanisms.
“While Sweden lacks domestic tyre manufacturers, Nynas’ research capabilities fill that gap by providing foundational insight into the chemistry and physics behind TRWP generation. Nynas’ rubber and asphalt labs are at the heart of this contribution,” says Pär Nyman, Nynas Technical Manager Tyre & Chemical Industries of Nynas.
Nyman adds, “One of the core insights driving this initiative is that wear particles cannot be fully understood by analysing tyres or roads in isolation. By studying both tyre composition and road structure, the project aims to develop a holistic view of TRWP formation, dispersion and toxicity.”
In parallel with the particle emission studies, the project will also include rolling resistance measurements of the different tyre and bitumen combinations – a parameter directly linked to greenhouse gas emissions.
With stakeholders like Volvo, Scania, KTH, KI and Nynas, the project is poised to set new benchmarks in TRWP research. It also demonstrates how interdisciplinary collaboration across academia, industry and material science can drive innovation in sustainability, the companies say.