Results of Initiatives to Reduce Tire and Road Wear Particles Presented at Conferences in Japan and Abroad

Results of Initiatives to Reduce Tire and Road Wear Particles Presented at Conferences in Japan and Abroad

Aug. 29. 2025

Sumitomo Rubber Industries, Ltd. (President and CEO: Satoru Yamamoto) is pleased to announce that the results of the company's initiatives to reduce tire and road wear particles (TRWP) generated by friction between tires and the road surface during car travel have been presented at conferences both in Japan and abroad. Recognizing the importance of understanding and reducing the environmental impact of TRWP, we have been working to reduce TRWP generation by enhancing the wear resistance of tires. We have been conducting surveys and research focusing on the three stages of TRWP, namely (1) generation, (2) dispersal, and (3) accumulation, and have presented the results of our investigations on the mechanism of (1) generation and the prevention of (2) dispersal. We aim to continue our initiatives to reduce environmental impact by diligently addressing challenges through scientific data-driven approaches and fulfilling our social responsibilities as a tire manufacturer. ■ What are TRWP? TRWP refer to fine particles generated by friction between tires and road surfaces during car travel. They are primarily a mixture of tire tread materials and road pavement materials. Tires are the only components of a vehicle that contact the road surface directly. They carry the weight of the vehicle and its passengers while performing fundamental functions essential for safe driving, such as "running (starting to move)," "turning," and "stopping." For these functions to work, there needs to be adequate friction between the tires and road surface. However, it has been found that during driving, TRWP (1) are generated, (2) disperse into the environment, and (3) accumulate, thereby causing various environmental impacts. (Illustration of) TRWP generation, dispersal, and accumulation ■ Approach towards TRWP Taking an all-inclusive approach to TRWP, from its generation to its behavior in the environment, we work with outside research institutions and companies to conduct research focusing on specific stages: (1) generation, (2) dispersal, and (3) accumulation. (1) Generation: Understanding the formation mechanism of TRWP We have been working with Nichireki Group Co., Ltd., a comprehensive road infrastructure solutions company, to investigate the formation mechanism of TRWP. We announced at the Tire Technology Expo 2025*1 held in March 2025 and the 30th Pavement Engineering Conference*2 held in August that we have obtained important data for understanding the formation mechanism, such as investigation methods and TRWP structural characteristics. We aim to continue efforts to understand the mechanism and develop technology to reduce TRWP generation from both perspectives of tire and road surface. (2) Dispersal: Research on characterization and prevention of TRWP dispersal We are working with Prof. Dr.-Ing. Falk Klinge, an aerodynamics expert at the Ostfalia University of Applied Sciences in Germany, to develop a TRWP collecting device that uses the flow of air produced around tires during driving. We are also in the process of establishing insights that can lead to dispersal reduction by analyzing the relationship between tire rubber compounds, driving conditions, and the characteristics of collected TRWP. During EuroBrake 2025*3 held in June 2025, we announced our success in visualizing the airflow around tires (aerodynamics) using wind-tunnel experiments in our collaborative research with Professor Klinge. In addition, we were able to demonstrate the concept of the collecting device through experiments using a prototype. The collecting device has a double-layered structure. Air is blown in from the outside to change the flow of air near the tire and road surface. The force of the wind after changing its direction is used to efficiently collect TRWP within the device. There are no other similar collecting devices on the market, and we view this as a major achievement of our research. Building on these findings, we will continue efforts toward practical implementation. (Illustration of) flow of air around tires changing depending on availability of collecting device (3) Accumulation: Quantitative analysis of TRWP and microplastics in environment TRWP are occasionally categorized as a type of microplastic. However, their physical and chemical properties, as well as their behavior in the environment, are thought to differ significantly. Working with Associate Professor Shuhei Tanaka at Graduate School of Global Environmental Studies, Kyoto University, we are developing a technique to differentiate and quantitatively analyze TRWP and microplastics, aiming to determine the amount of both TRWP and microplastics present in the environment. We are also working to establish fundamental knowledge for preventing and minimizing TRWP dispersal and accumulation. ■ Initiatives to reduce environmental impact Among the seven material issues announced in October 2024, "Climate Change," "Circular Economy," and "Biodiversity" are designated as environmental-related items. Particularly with the specific focus on biodiversity, it is pointed out that "The Company's businesses entail risks that impact ecosystems using natural resources and chemical materials as well as the process of product usage. To ensure that the benefits of ecosystems and natural resources are passed on to future generations, we strive to minimize the negative impacts of our business activities and work towards the conservation and restoration of biodiversity." With regard to TRWP, we will also aim to minimize impacts on biodiversity based on these material issues. ■ Future plans Many aspects of TRWP remain unclear, especially its environmental impact, which requires further research and validation. We have been participating in the TIP*4 of the WBCSD*5 since its inception, involved in activities such as research and studies on TRWP, the establishment of evaluation methods, and dialogues with stakeholders. We are also a member of the JATMA*6 and JRMA*7, working on developing ISO standards related to the assessment of TRWP and other efforts. Besides participating in activities by industry associations, we are also conducting our own studies, including the research presented here. We are committed to diligently addressing TRWP-related challenges through a scientifically data-driven approach, in our efforts to reduce environmental impact and fulfill our social responsibilities. *1 Technical presentations and exhibitions related to tire manufacturing and other fields, held in Europe since 2001. Participants range from tire manufacturers, material suppliers, to public research institutions, who present their research findings. *2 Research conference hosted by the Japan Society of Civil Engineers (JSCE). Participants from universities, government agencies, road construction companies, and pavement material manufacturers present and discuss academic achievements in pavement engineering. *3 International conferences and exhibitions on brake technology held mainly in Europe. Participants include automobile manufacturers, brake component manufacturers, research institutions, etc. to present technologies and exchange information. *4 TIP: Tire Industry Project /Industry association comprising 10 global tire manufacturers *5 WBCSD: The World Business Council for Sustainable Development *6 JATMA: The Japan Automobile Tyre Manufacturers Association, Inc. *7 JRMA: The Japan Rubber Manufacturers Association For your reference: Material issues identified by the Company: https://www.srigroup.co.jp/english/sustainability/materiality.html