Vehicle tires release six million metric tons of tire particles into the environment annually. These particles contain a cocktail of life-threatening chemicals, contributing to 52% of road-related air pollution worldwide. Like many industries, tire manufacturers are early in the process of reducing their environmental impact with new materials and improved recyclability for end-of-life products.
When we breathe, tiny particles enter our bloodstream, impacting our health. Rainwater washes the relatively large particles into rivers and oceans as microplastics, risking aquatic life. For example, consider the mass-die off of Coho Salmon in the US attributed to the compound 6PPD-quinone used in vehicle tires. And those microplastics that settle into the soil significantly threaten plant life, affecting the entire food chain.
While concepts like curbing car usage or shifting loads on heavy vehicles to reduce tire wear can make a difference, addressing the root cause by transitioning toward sustainable tire production appears to be a more practical solution.
The path to green tire manufacturing isn’t direct. The tire industry faces significant challenges despite recent material and technology improvements.
Can Tire Manufacturing Become Sustainable?
Green tire production must overcome many hurdles, requiring new materials and manufacturing techniques. Finding and developing alternatives that meet the oft-conflicting criteria of sustainable manufacturing and on-road performance is a pressing challenge. For example, tire manufacturers are exploring other sources of renewable alternatives and biomaterials for tire manufacturing and preserving natural resources.
Improvements in tire sustainability hinge on the adoption of renewable raw materials. The concept of petroleum-based synthetic rubber is no longer viable. And while harvesting more natural rubber is an option, adopting its widespread production for tires could lead to deforestation and habitat loss. New sources of rubber-like materials include plants such as the Russian dandelion and guayule.
The primary material in natural rubber is latex extracted from rubber trees. However, latex rubber is also extractable from the Russian dandelion. Unlike rubber trees, which take seven years to produce latex, the Russian dandelion is ready for harvesting in about a year.
While native to South America, around 90% of rubber tree latex is exported from Hevea brasiliensis plantations in Southeast Asia. Rubber trees require specific growing conditions and can only flourish in particular climates. In contrast, Russian dandelions can be widely cultivated, even in areas where commercial farming is not feasible.
The Russian dandelion requires minimal to no chemical fertilizers, herbicides or catalysts to extract the latex it contains. Since dandelion seeds can be harvested locally, they also contribute to a reduction of shipping-related CO2 emissions compared to rubber trees.
The European Tyre & Rubber Manufacturers’ Association estimates that 76% of all the natural rubber produced goes into making tires. And this percentage will continue to increase, seeing the growing demand for vehicles globally.
Harvesting guayule, a desert plant native to the Southwestern US and Mexico, is an innovative approach to cope with the drawbacks of natural rubber. It’s a shrub that can thrive in dry regions with minimal maintenance, making the process of extraction faster and more resource-efficient.
Bio-based materials aren’t the only option to reduce the need for raw rubber and oil extraction.
In addition to researching alternative sources of natural rubber, manufacturers have developed strategies to reuse rubber from old tires. According to the Tire Industry Project for the World Business Council for Sustainable Development, four billion end-of-life tires reside in landfills.
For many years, minimal effort was invested in determining the impacts that landfill tires create. But we now know that they contribute to groundwater contamination, produce harmful gas emissions, and increase the risk of uncontrollable fires that emit toxic smoke that can endanger human health.
Integrating recycled materials stabilizes the demand for raw materials and is a better environmental option. Natural and synthetic rubber, fossil fuels, steel, and carbon black can be recovered by recycling tires. Allied Market Research predicts the tire recycling industry will grow by 3.4% a year from 2023 to 2032 — more than doubling in size.
Michelin, a leading tire manufacturer, is exploring manufacturing tires with recycled and sustainable materials. Similarly, Bridgestone Tire has partnered with companies worldwide to recycle their end-of-life tires.
Clean Carbon Black
Carbon black is a material used in the tire’s tread and sidewalls to improve durability. Traditional production of carbon black, which involves partially burning oil, is not an environmentally responsible process. Now, companies have begun extracting carbon black for reuse from end-of-use tires, which is a much cleaner process.
Introducing silica into tire compounding, the process of formulating the rubber mixture used to create the tread and other components of a tire, can yield essential benefits. Silica improves vehicle fuel economy and improves tire life.
Unfortunately, the production of silica for tires has an environmental cost. However, green silica, which is derived from rice husk ash and can be made using renewable energy, is under investigation. Testing has shown comparable performance to traditional silica. Producing silica from agricultural waste costs less and significantly reduces environmental impact.
Sustainably sourced Butadiene and Isoprene.
Tire manufacturers have started to replace oil-based butadiene and isoprene, the two compounds used to produce synthetic rubber, with renewable plant-based alternatives. Extracted from sugar-producing plants using bacteria and yeast, this isoprene does not require high temperatures, resulting in a low-CO2 synthetic rubber.
Transitioning to sustainable tire manufacturing often involves high upfront costs, including expenses related to research and development, sourcing of renewable materials, new machinery, energy consumption and emission control measures, hiring and training of skilled staff, and employing advanced technologies.
Striking a balance between sustainability and the market price is essential to remaining competitive. However, considering the expenses mentioned above, achieving this balance is difficult.
Manufacturing tires using petroleum-based materials and high-temperature processes has been the industry norm for decades. Shifting consumer perception and awareness toward green alternatives is crucial yet challenging.
Emerging Technologies & Advancements
Manufacturers have devised innovative ways to address these formidable challenges by collaborating with researchers and industry experts. By following advanced manufacturing strategies, the tire industry strives to reduce waste, lower energy consumption, and minimize environmental impact while ensuring high-quality, cost-effective green tires.
Nanotechnology and 3D printing
In the future, nanotechnology could produce low-impact improvements in the tread compound that provide greater fuel efficiency, wear resistance, and, consequently, longer tire life. These materials could be used in local production facilities with 3D printing technology to significantly reduce transportation costs. Tires are bulky items to transport, making them near the customer rather than shipping them thousands of miles, could reduce carbon emissions from shipping by up to 10%.
Electromagnetic induction curing
Electromagnetic induction heating of the metal tire mold, instead of steam, saves almost 64% of the energy required per tire and is compatible with conventional curing presses, conserving resources and capital.
Smart airless tires
Another advancement in the tire industry is the adoption of intelligent or self-regulating tires. Unlike traditional tires, these tires have sensors and valves that monitor and adjust the pressure accordingly. These systems are currently in use in large, over-the-highway trucks. Airless tires developed by several tire manufacturers could improve fuel efficiency and reduce waste.
Your next car may include reports on the dashboard about tread wear and driving tips to extend tire life.
Going Beyond Current Practices
Every industry making genuine sustainability efforts face many challenges as society transitions from fossil fuels and oil-based materials. The tire industry includes leaders and laggards.
Bridgestone aims to reach a 100% sustainable tire production milestone by reducing raw material consumption, recycling resources, and expanding the utilization of renewable resources. The company is also exploring bio-based material and new sources of natural material to make green tires, said Bill Niaura, director of sustainable materials and circular economy at Bridgestone, on the Earth911 podcast. The company will invest another $42 million for the commercial production of guayule rubber at the end of this year.
Likewise, Goodyear is moving on from petroleum-based products and is exploring alternative resources to fulfill its promise of introducing 100% sustainable tires by 2030. The company aims to use materials including soybean oil, rice husks, green silica, polyester from plastic waste, and carbon black from plant-based oil or methane in its future tire lineup.
How You Can Reduce The Environmental Impact
While tire industry leaders play their part toward sustainable tire production, the everyday tire user also has a role. After all, change doesn’t come from the top down alone; it’s a partnership that starts with each of us.
If you are an aggressive driver, change your driving habits and keep within the speed limit to reduce how hard and often you brake. Avoiding aggressive driving reduces tire wear, saving you money in the long run. Properly maintain your tires to ensure the longest possible life.
When replacing tires, look for options made from sustainable materials. Or buy tires from brands that prioritize sustainability. For example, Pirelli marks tires made from at least 50% bio-based or recycled materials with two circular arrows.
Opt for tires that feature lower rolling resistance. Low rolling resistance tires require less force to move the car, reducing gas emissions every mile. A more durable tire will require fewer replacements, reducing waste and resource requirements.
Whenever possible, purchase tires from a nearby store; importing or purchasing tires individually or in sets of four isn’t sustainable due to the increased emissions of less-efficient transportation.
Avoid oversized or undersized tires just for the aesthetics of your vehicle. Oversized tires consume more fuel and produce higher emissions, while smaller tires will wear out more quickly. The recommended size from tire manufacturers is the best choice for sustainable driving.
If your tire is worn but the construction is in good shape, consider retreading rather than replacing the tires. While not available everywhere, tire retreading saves money, requires fewer resources, and is more eco-friendly than purchasing new tires.
When it’s time to say goodbye to your car, bicycle, or truck tires, adopt a practical and thorough approach by recycling them responsibly. Use Earth911’s Recycling Search to find a recycling facility nearby, or, if one isn’t available, contact your community’s solid waste management district or local government to inquire about recycling options.
Only combined efforts can achieve sustainable tire manufacturing, use, and reuse to fight the problem of climate change.
About the Author
Hadie Erfan is a tire professional in the automobile industry. His experience helps him identify the right tire and how it will perform on different vehicles. He runs “Tiredepth.com,” where he guides readers about tire choices and promotes safe driving.