Trends in particulate matter generation from truck and bus radial tires using a wear tester

This study aimed to analyze the trend of particulate matter (PM) generation from tires by nonexhaust systems. These types of PM are lesser known than the airborne PM generated from automotive exhaust systems. Specimens with rubber formulations similar to commercial tires for trucks and buses were artificially abraded, and the generated PM was analyzed. Abrasion of a specimen made of butadiene rubber, which is a synthetic rubber, generated lesser PM than a natural rubber specimen. This reduction of PM generation was particularly significant for PM10. Furthermore, using carbon black (a filler in tires) having small sized particles, the generation of PM2.5 was reduced to a large extent. To study the influence of tire aging on the increased generation of PM, rubber specimens were analyzed after prolonged exposure to a high temperature.