An act we often take for granted is, in reality, the culmination of decades of research in tribology, materials science, and chemistry. Braking is the fundamental principle that ensures our safety in motion: the controlled conversion of kinetic energy into heat.
In this article, we’ll explore the science behind safe braking, review the evolution of friction materials, and analyze the challenges that will define the future of the industry, with a key player on the horizon: the EURO 7 regulation.
If we go back to the 1970s, the era of “muscle cars,” braking safety was measured by a single metric: “the shortest stopping distance is the safest.” Environmental considerations were secondary, and brake pad formulations had much more permissive rules.
The star material of the time was asbestos. It was cheap, heat-resistant, and very effective. However, the same fibers that made it such a good friction material proved to be extremely dangerous to health, causing diseases like asbestosis. Starting in the 1980s, its prohibition was the first major turning point for the industry.
This led to a constant evolution:
Every time we brake, it’s not just mechanical friction that occurs. At the interface between the pad and the disc, at temperatures that can exceed 600-700°C, complex tribochemical reactions take place. These reactions generate a small amount of material that is released into the atmosphere as fine particles (PM10 and PM2.5).
It is estimated that brake wear is responsible for about 21% of traffic-related PM10 emissions. And the composition of this dust is crucial.
This “copper-free race” has forced the entire global industry to reformulate its products from scratch, seeking alternatives that offer the same safety and performance without this metal.
If the elimination of copper was the great challenge of the last decade, the EURO 7 regulation is the challenge that will define the present one. For the first time, a European emissions regulation will not only focus on exhaust gases but also on non-exhaust particle emissions.
This includes particles generated by tire wear and, very prominently, brake particle emissions.
EURO 7 sets strict limits on the amount of particulate matter (by mass, mg/km) that a vehicle can emit when braking. This represents a paradigm shift: it’s no longer just about what the pads are made of (copper-free, antimony-free), but also how many particles they release into the environment.
This challenge affects all vehicles, including electric vehicles (EVs). Although EVs use regenerative braking, they still need friction brakes for emergency situations (ABS, ESP) and for intense braking, so they will also have to comply with these new limits. The industry must, therefore, design brake systems (pad and disc) that minimize dust generation, a top-tier engineering challenge.
The future of the automotive industry brings two revolutions that directly impact the braking system:
The friction industry is at an exciting crossroads. The days when only safety and cost mattered have given way to a complex balance that includes public health, environmental impact, and adaptation to new mobility technologies.
Overcoming the challenges of copper-free formulations, meeting the strict emission limits of EURO 7, and designing brake systems for electric and autonomous vehicles require unprecedented collaboration between raw material manufacturers, pad producers, and vehicle developers. Innovation in materials and a deep understanding of tribology are, now more than ever, the key to continuing to ensure safe braking in a world in constant motion.
