HANOVER, Germany — Group Michelin has developed a "light particle" analysis system that it claims will help it advance the study of tire road wear particles (TRWP), the tiny debris generated by the friction between tires and the road surface.
The technology makes it possible to "capture, sort, count and qualify particles as close as possible to the tires with high levels of precision and reproducibility," Michelin stated in a presentation this week at the Tire Technology Expo in Hanover.
TRWP are on average are the size of a human hair (100 µm), Michelin said, and form a complex mixture comprising, in equal parts, a combination of tire rubber and minerals and other road elements.
Michelin's disclosure comes at a time when questions are being raised about TRWP and their potential health and environmental impacts.
Such concerns make it essential to use reliable, reproducible and standardized measurements and will be a fundamental step in understanding more clearly the environmental impact of these wear particles and devise solutions to mitigating them.
The analysis system is intended to support the development of tires with wear particles "bio-assimilable by nature."
In connection with developing the system, Michelin carried out a study on TRWP using the process and made available the results to the European Tire & Rubber Manufacturers' Association (ETRMA).
The study, acccording to Michelin, made it possible "to better quantify the number of particles which contribute to atmospheric pollution." These included fine particles, or particle matters with the diameters of between 10 µm and 2.5 µm (PM10 and PM2.5).
These figures, Michelin claimed, "have never been verified with such precise experimental measurements until today."
The first results of the study showed that among the particles emitted by a tire, on average 1.3% are PM10 and 0.16% are PM2.5 and are likely to be found suspended in the air.
For Michelin, such precise quantification is important to increase its understanding of the links between the tire, the road and driving behavior.
In December 2022 and in March 2023, data from Michelin's study were the subject of two scientific articles.
Further afield, it said, scientific organizations and/or government agencies can use the data to estimate urban pollution and develop air-quality measurement simulation models.
With the technology made available to ETRMA, the trade body will carry out "a larger-scale measurement campaign with the help of an independent organization," Michelin added.
The study, according to Michelin, will be launched in 2024 for a duration of approximately 18 months. Michelin said its approach will be complementary to the Euro7 vehicle emissions standard, which was adopted by the European Parliament earlier this month.
The set of standards aims to make it possible to define regulatory thresholds for tire abrasion in order to reduce the quantities of particles emitted in Europe.
The regulation will be based on a recent test method introduce by the United Nations ECE, based on which tire weight loss due to abrasion will be expressed in milligrams per kilometer per metric ton of load on the tire.
Michelin said its research into TWRP, combined with its knowledge of materials and tire design, helped it develop tires that have exhibited 5% less wear emissions over a five-year (2015-2020) period.
Last year Michelin established a a common laboratory, dubbed "BioDLab," with the French National Centre for Scientific Research (CNRS) and the University of Clermont Auvergne, with a mission to understand the biodegradation of wear particles and develop tools for finding concrete solutions to make them bio-assimilable by the environment.
