A concept for reducing PM₁₀ emissions for car brakes by 50%

With regard to airborne particles with an aerodynamic diameter of less than 10 µm (PM₁₀), in countries in the European Union, the mass of brake emissions equals approximately 8–27% of the total traffic-related emissions. Using a research methodology combining tests at different scale levels with contact mechanics simulations and PM₁₀ chemical characterization, the REBRAKE EU-financed project had the following aims: i) to demonstrate the possibility of reducing the PM₁₀ fraction of the airborne particulate from brake wear by 50 wt%; ii) to enhance the general understanding on the physical and chemical phenomena underlying the brake wear process. The results achieved so far indicate that it is possible to design a disc brake system for a European standard car affording at least a 32 wt% PM₁₀ emission reduction using a standard European pad and a heat-treated rotor. A further reduction to 65 wt% PM₁₀ emission could be achieved with NAO pad material and the same heat-treated disc.