Old Brake Pads Recycling: Complete Guide
Brake pad recycling is important because a vast number of used brake pads end up in landfills each year. It is estimated that over 200 million brake pads are sold annually in the United States alone. Since brake pads contain materials that do not naturally decompose, dumping them in landfills poses an environmental concern.
Efforts to recycle brake pads began in the 1990s as part of a push to divert more waste from landfills. Several companies emerged that specialized in collecting used brake pads from mechanics and vehicle fleets, then recovering the metals and other recyclable components. However, recycling brake pads has remained challenging over the years due to factors like inconsistent quality, high processing costs, and lack of recycling regulation. As a result, recycling rates for brake pads are estimated to still be quite low, often under 15%.
There is growing pressure on the automotive industry to improve brake pad recycling as part of a broader effort to develop the “circular economy.” New technologies and processes are aiming to make brake pad recycling more efficient and economically viable. Implementing effective recycling programs could significantly reduce the environmental impact of spent brake pads in the future.
How Brake Pads Work
Brake pads are made up of various materials that provide the friction needed to stop a vehicle’s wheels from spinning. The composition of brake pads can include:
Semi-metallic pads that contain 30-70% metal alloys such as copper, iron, and steel (Source). These composite metals provide the pad’s hardness and durability.
Ceramics like aluminium oxide, zirconium, and silicates that help provide smooth braking and dissipate heat (Source). Ceramics reduce noise and brake fade.
Binders and fillers made of rubbers and graphites hold the pad together while insulating and lubricating it.
When the brake pedal is pressed, hydraulic pressure forces the brake pads against the surface of the brake rotor. The resulting friction between the pads and rotor slows the spinning of the wheels until they come to a stop.
Over time and repeated braking, the continual friction wears down the pad material, decreasing braking performance. This is why brake pads need to be periodically inspected and replaced.
Environmental Impact
Traditional brake pads contain hazardous materials like copper, lead, and asbestos that can contaminate the environment when the pads wear down or end up in landfills (1). Copper from brake pads accumulates in waterways, harming aquatic life (2). One study found that 35% of brake pad mass lost from braking ends up airborne, contributing to particulate matter pollution (3).
Asbestos fibers are released into the air during braking, posing a health hazard if inhaled. Though asbestos use in brake pads is now limited in many countries, legacy asbestos brake pads continue releasing fibers. According to the EPA, automotive brakes account for nearly half of all asbestos used in the US (4).
Recycling brake pads helps reduce environmental contamination. Materials like copper and asbestos can be captured and disposed of properly rather than polluting landfills. Recycling also decreases the need for new mined materials, saving natural resources.
By extracting and reusing materials from old pads, recycling significantly lessens the environmental impact compared to manufacturing new pads. One study found that recycling brake pads reduced energy use by 85% compared to making new pads (5).
Sources:
(1) https://www.sciencedirect.com/science/article/abs/pii/S2214785323028201
(2) https://www.otip.com/Why-OTIP/News/How-brake-dust-from-your-vehicle-can-impact-your-h
(3) https://www.azom.com/news.aspx?newsID=58338
(4) [EPA Source]
(5) [Recycling Study Source]
Recycling Challenges
There are several key challenges when it comes to recycling brake pads once they have been worn out and replaced. First is the logistics of collecting the used brake pads in the first place. Since pads are replaced at repair shops and dealerships across the country, there needs to be an efficient system for gathering up those used pads and transporting them to recycling facilities. Many pads currently just end up in landfills because the infrastructure is not in place for proper collection 1.
Another major issue is sorting and separating the different materials in brake pads once collected. Pads consist of various metals, abrasives, bonding materials, and shims. All of these components need to be effectively separated in order to recycle them properly. This requires specialized equipment and expertise that is not widely available currently 2.
Finally, finding markets for all the recycled brake pad materials can be difficult. The metals can be sold to scrap metal buyers, but the abrasives, bonding agents, and shims need manufacturers willing to reuse them in new pads or other products. Building reliable markets for these recycled materials is key for economically viable recycling operations.
Recycling Process
Worn brake pads are typically collected from mechanics, repair shops, and automotive recycling facilities. Once collected, they enter a sorting process to separate the metallic backing plate from the friction material.
Some facilities use hammer mills or shredders to liberate the friction material from the steel backing plate. The friction material breaks down into a powder, while the steel remains in larger chunks. The two materials can then be physically separated using screening, air classification, density separation, or other methods. Electromagnets may also be employed to extract any remaining steel from the friction powder.
Another approach is cryogenic recycling, where the material is frozen using liquid nitrogen. The extreme cold makes the friction material brittle enough to detach from the backing plate through vibration and mechanical agitation. The materials are then sorted.
Other recycling plants use special equipment that grinds down the friction material into fine particles but leaves the steel plate relatively intact. This also allows the two components to be easily separated.
The friction material goes through additional processing to remove any remaining contaminants before it can be reused in manufacturing new brake pads. The steel backing plates may be sent to steel recycling facilities.
Reusing Brake Pad Materials
The materials in worn brake pads, including copper, iron and other metals, can be reclaimed and reused in various manufacturing processes. For example, up to 97% of the iron content in used brake pads can be recovered through shredding, magnetic separation and other techniques at recycling facilities [1].
The reclaimed metals from used brake pads can be used as raw materials to make new metal products and materials. The iron can be remelted and reused in steel and iron manufacturing. The copper can also be remelted and reused to make new copper products or copper-based alloys like brass. Recycled brake pad metals are a more sustainable source for these industries.
In addition to metals, brake pad friction materials like resins and fibers can potentially be reclaimed and reused. Researchers have explored methods to chemically break down and process the polymers in used brake pads to recover materials like phenolic resins. These recycled resins can then be mixed into new brake pad compositions [2].
Overall, recycling programs enable the reclamation of brake pad materials for manufacturing uses. This helps divert waste from landfills and reduces the carbon footprint of producing new materials from raw sources.
Legislation Around Recycling
There have been efforts in recent years to pass legislation mandating and encouraging the recycling of brake pads. In 2010, California passed the California Motor Vehicle Brake Friction Material Law, which required brake pads to reduce copper and other toxic metals by 2021. This was an effort to make brake pads more environmentally friendly and increase recycling rates. The law bans brake pads containing asbestos and more than 5% copper.
Similarly, Washington state passed the Better Brakes Law in 2010 to restrict toxic metals in brake pads and encourage recycling. This law limits cadmium, chromium, lead, mercury, and asbestos in brake materials.
These legislative efforts aim to reduce the toxicity of brake pads so they can more easily be recycled. They also bring awareness to the importance of proper brake pad recycling to reduce environmental contamination from heavy metals.
Business Opportunities
There are several companies already involved in recycling brake pads and profiting from the growing need for sustainability. Knorr-Bremse has developed a pioneering process for recycling worn brake blocks from trains, avoiding waste and saving raw materials (Knorr-Bremse). As demand grows for recycled brake pads, especially in the automotive industry, there are opportunities for new recycling businesses to emerge. Entrepreneurs could start a brake pad collection and recycling service, partnering with mechanics and auto shops to acquire used pads. The recycled materials could then be sold to brake pad manufacturers.
Another business idea is offering brake pad take-back programs, where customers receive a discount on new pads when they return the old ones for recycling. This model helps ensure a steady supply of used pads to support the recycling process. Overall, the growing focus on sustainability and circular economy principles means there is increasing potential to profit from brake pad recycling services in the future.
Future Outlook
New technologies are emerging that aim to improve the recycling process for brake pads. For example, companies are developing ways to more efficiently separate the copper from the other materials in used brake pads through new shredding and sorting methods (Rethinking Brake Pads: Are They Necessary for Electric Vehicles?). This could increase the value of the recycled metals and reduce overall waste.
There is also a push to increase recycling rates of used brake pads, which currently sit around 50% globally. Automakers like Volkswagen are partnering with brake manufacturers to implement take-back programs and educate consumers on proper disposal methods (The braking system of the future). Governments may consider legislation to mandate higher recycling targets.
Looking towards 2030 and beyond, the adoption of electric vehicles with regenerative braking could reduce overall brake pad usage and waste. However, brake pads will still be needed and recycling efforts will remain important. The goal is to turn brake pads into a circular economy, where the materials are continuously reused rather than discarded. With emerging technologies and greater public awareness, brake pad recycling is likely to become more efficient and widespread in the future.
Conclusion
Brake pad recycling is essential to reduce the waste produced by discarded brake pads, which contain harmful materials like copper and asbestos. As we’ve explored, brake pads wear down through friction when in use, producing brake dust composed of various metals, fibers, bonding materials and abrasives.
This brake dust poses environmental and health risks as it washes into waterways or becomes airborne. While some progress has been made in developing alternative brake pad materials and recycling methods, there is still room for improvement. Key takeaways for readers include:
- Brake pads contain potentially hazardous materials and should not be discarded in landfills.
- Recycling brake pads recovers valuable materials like iron, copper and graphite for reuse.
- Brake pad recycling helps reduce water and air pollution caused by brake dust.
- More legislation, infrastructure and consumer awareness is needed to improve recycling rates.
In closing, recycling old brake pads is a crucial step in reducing the environmental impact of vehicles. With greater innovation and effort, we can work towards responsibly managing brake pads at end-of-life rather than treating them as waste. This will benefit the health of our communities and environment for generations to come.