Sponsored By

‘Microplastics’ Emissions From Car Tires Under Scrutiny‘Microplastics’ Emissions From Car Tires Under Scrutiny

Researchers estimate that tire abrasion is responsible for about one-third of all “microplastics” emissions annually in Germany.

Stephen Moore

January 14, 2025

3 Min Read
pile of tire-abrasion particles with euro coin for scale
Rubber abrasion at a typical tire-wear rate of 30 g per 100 km is pictured. Scientists are investigating the factors that cause and influence this phenomenon.Image courtesy of Martin Gießler, Karlsruhe Institute of Technology

The German Federal Environment Agency estimates that tire contact with road surfaces produces at least 100,000 tonnes of abrasion particles annually. This corresponds to approximately one-third of all “microplastics” emissions released every year in Germany. It is debatable, however, whether micrometer-scale rubber particles should be categorized as microplastics given that tire manufacture is not normally associated with the plastics industry. Perhaps public funding for research projects is easier to come by if the research is associated with microplastics.

EVs generate greater emissions

Because of their heavy batteries and higher mass, vehicles with an electric drive often produce more tire abrasion than those with a combustion engine. Scientists from the Karlsruhe Institute of Technology (KIT) and Fraunhofer Institute for Industrial Mathematics have launched the RAMUS project, which deals with tire-abrasion measurements and simulation, to investigate how electric vehicles (EVs) produce these abrasion particles. In order to develop a forecast model for tire abrasion, they are testing tires on a test rig by simulating operating cycles that represent real vehicle usage behavior in condensed form.

While electrified delivery traffic plays a key role in climate-neutral mobility, tire abrasion remains a challenge. Due to the weight of the battery and the high starting torques, these vehicles will release higher quantities of tire particles in the form of “microplastics” compared with conventionally powered vehicles, according to the scientists. These particles appear in the air as fine dust, in water as sediments, and in soil as contaminants. “In contrast to the sources of pollution, such as exhaust gases, which were the focus so far, little research has been done on the factors that favor the formation of these particles,” explains Dr. Martin Gießler, head of the Tire-Wheel-Road Surface Research Group that is part of KIT’s Institute of Vehicle System Technology (FAST).

Related:Easy-to-process Particle Foam Targets Auto Composite Applications

Research based on real traffic data

The Euro 7 standard will introduce tire abrasion limits from July 1, 2028, for passenger cars, light commercial vehicles, and heavy commercial vehicles and buses, with the heaviest vehicles subject to regulation starting on April 1, 2032. “To reduce abrasion and comply with the new limit values, we need to investigate more closely how abrasion particles are formed and how a number of factors, such as the vehicle weight or the type of tire, bear on the amount of abrasion,” Gießler says. Other possible influencing factors include driving behavior, such as acceleration and braking; road conditions, including temperature and wetness; and traffic conditions such as congestion.

Related:Firm Prospects for Thermosets in Auto Sector

“We are using mobility data and driving profiles of electric delivery vehicles to define condensed operation profiles for the abrasion tests on the tire test rig. The data obtained in these tests are then used to develop a simulation-based forecast model,” explains Gießler. The researchers have set up a tire test rig with a real asphalt surface to measure the force transmission and abrasion behavior of the tire under various operating conditions.

Abrasion prediction via modeling

In addition, the researchers want to develop a tire model based on rig tests and simulations, which will provide large amounts of data that describe the wear of virtual tires. Data obtained from the real and virtual tests will then be integrated into a forecast model to predict the influence of various factors, such as type of tire, type of vehicle and load, or driving style, on tire abrasion. Since the consortium intends to make the project results accessible to the public, it will present its method in publications and make the data obtained available on a freely accessible platform.

Related:Conductive PPE Blend for Auto Exteriors Is Inline Paintable

Germany’s Federal Ministry for Digital and Transport is funding RAMUS with a total sum of €199,738 ($205,154) within the scope of the mFUND innovation initiative. The project was launched in December 2024 and runs through 2026.

About the Author

Stephen Moore

Stephen has been with PlasticsToday and its preceding publications Modern Plastics and Injection Molding since 1992, throughout this time based in the Asia Pacific region, including stints in Japan, Australia, and his current location Singapore. His current beat focuses on automotive. Stephen is an avid folding bicycle rider, often taking his bike on overseas business trips, and a proud dachshund owner.

Sign up for PlasticsToday newsletter

You May Also Like