The history of wheels and tires dates back thousands of years. The invention of the wheel is considered one of humanity’s greatest innovations, with the earliest known stone wheels appearing in ancient Mesopotamia around 3500 BC.
Over time, the use of logs as rollers for transportation led to the development of wooden disks with three carved segments, which served as the oldest known wheels. As civilizations advanced, so did the technology behind wheels and tires. To keep wooden wheels from falling apart, bands of metal were placed on them, but this meant not getting very good traction in many situations. The earliest form of tires involved leather bands wrapped around wooden wheels. These primitive tires provided some cushioning and improved traction.
As civilizations advanced, so did tire technology. In the 19th century, the invention of the pneumatic tire enabled the rise of the automotive industry. Scottish veterinarian John Boyd Dunlop patented the first practical pneumatic tire in 1888. It featured an air-filled tube encased in a rubber outer layer, providing a smoother and more comfortable ride. More importantly, it created a flat contact patch that could grip the road more.
But, pure natural rubber kind of sucks for tires. It’s not durable enough for long-term use, and tends to fall apart. Goodyear’s discovery of the vulcanization process in the mid-19th century revolutionized rubber manufacturing. Vulcanization involved treating natural rubber with sulfur, making it more durable, elastic, and resistant to temperature changes. This breakthrough paved the way for the modern tire industry and allowed for the mass production of high-quality rubber tires. Later, synthetic rubber compounds outperformed even the best vulcanized rubber.
Today, tires are a complex combination of different materials carefully engineered to provide optimal performance and safety. They can be made from dozens of materials, both synthetic and natural, and they’re more durable and useful than ever, and this field will continue to improve over time.
Carbon black, a material that’s dirty and dirty to make, plays a crucial role in modern tire production. It is a material derived from the incomplete combustion of hydrocarbons, such as oil or natural gas. Carbon black is added to the rubber compound used in tire manufacturing to improve various properties, including tread wear, traction, and overall durability. It also helps them to have the black appearance they usually have.
But, as I mentioned, making the stuff is not great for the environment, so finding alternatives or finding ways to get carbon black into a circular economy, would greatly help the environmental situation with tires.
Fortunately, Continental figured out how to improve things at its tire plant in Korbach, Germany. The company has incorporated recovered carbon black (rCB) into its newly produced Super Elastic solid tires, reducing the reliance on fossil raw materials and minimizing CO2 emissions. An impressive 60% of renewable and recycled materials are already present in tires like Continental’s SC20+, thanks to the abundant natural rubber used. Looking ahead, Continental has set an ambitious goal to utilize 100% sustainable materials in their tire products by 2050. This commitment to sustainability reflects their dedication to a greener future.
“Sustainability is becoming increasingly important in the specialty tire segment. Our Super Elastic solid tires combine low rolling resistance, long service life and a comparatively high proportion of sustainable materials,” says Matthias-Stephan Müller, product manager for material handling tires in Continental’s Specialty Tires business area.
The recovered carbon black is sourced from Pyrum Innovations, one of Continental’s partner companies. Through their specialized pyrolysis process, Pyrum effectively breaks down end-of-life tires in industrial furnaces, extracting and recycling valuable raw materials contained within. This innovative approach enables the extraction and recycling of resources from end-of-life tires, contributing to a more sustainable future through recycling.
But, don’t expect to use recovered tires on a passenger vehicle any time soon. Solid tires have a high load capacity and are extremely stable, puncture-proof, maintenance-free and highly economical, but they are mainly used in material handling by forklift trucks, airport vehicles, heavy transport vehicles, sideloaders, platform trucks and other industrial vehicles.
In other words, the process is only suitable for low-speed tires, and not high-speed tires yet. But, this is still great news because there are so many solid tires in use globally.
Electric-powered forklift trucks dominate the realm of intralogistics, with battery range and charging times as key considerations. To enhance vehicle range, incorporating tires with low rolling resistance is crucial for minimizing energy consumption. By utilizing rubber compounds in these recycled tires, we can achieve high energy efficiency and reduce the overall energy consumption of specialty vehicles, while also conserving valuable natural resources.
“Our customers want to make their operating processes even more environmentally friendly, resource-saving and efficient.” Müller explained. “Forklift trucks, for example, are required to do more work in the shortest possible time. This means moving heavier loads and traveling further distances at higher speeds. This is where Continental comes in with its customized tire solutions.”
Continental says it is actively exploring future applications for the recovered carbon black. In collaboration with Pyrum, the tire manufacturer is currently engaged in refining and expanding the tire recycling process through pyrolysis for end-of-life tires. This partnership aims to enhance efficiency and sustainability in tire production while preserving the original intent.
So, this recycling technology will hopefully make its way into tires on highway vehicles.
The company also say that this is just part of a much wider effort to clean up. Incorporating recovered carbon black from end-of-life tires is a crucial step towards embracing circular business practices in Continental’s tire production. The company says it is committed to tirelessly advancing innovative technologies and sustainable products and services across its entire value chain. From sourcing sustainable materials to recycling end-of-life tires, Continental is dedicated to achieving 100 percent carbon-neutrality along its entire value chain by 2050, at the latest.
Hopefully Continental gets things figured out to make better recycled tires soon, both for more low-speed electric vehicles and for our highway-driven EVs. The sooner we can use more sustainable and recyclable materials in all applications, the better.
Featured image provided by Continental.
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