Continental is further advancing its commitment to sustainability by integrating renewable and recycled materials into its tyre production processes
Dedicated to the principles of the circular economy, the company is also motivating its suppliers to innovate and provide increasingly sustainable materials for tyre manufacturing. In 2024, renewable and recycled materials made up an average of 26% of Continental’s tyre production. The company has set an ambitious target to raise this figure to at least 40% within the next five years.
Expanding the Use of Sustainable Reinforcement Materials
One of Continental’s primary goals is to identify and implement more sustainable alternatives to traditional raw materials used to reinforce tires. These reinforcement materials are crucial for ensuring dimensional stability and maintaining tyre performance throughout their lifespan. In passenger car tires, reinforcement materials—mainly steel and textiles—constitute approximately 18% of the total materials used, and this proportion is even higher in commercial or specialty vehicle tires. To address this, Continental is increasing its use of recycled steel and polyester yarns made from recycled PET bottles. Additionally, the company is incorporating more sustainable manufacturing methods, such as COKOON bonding technology, in its tyre production. Innovative alternatives are also being explored across all raw material groups, including synthetic rubber derived from used cooking oil, resins from bio-based waste, and silica sourced from rice husk ash.
Matthias Haufe, Director of Materials Development and Industrialisation at Continental Tires, explains, “We are not reinventing the wheel, but the tyre, with more sustainable materials and more environmentally friendly production processes. It’s not just about the rubber itself. We also focus on the materials that shape the rubber and make tyres stable and safe. Recycled steel and polyester yarn made from recycled PET bottles are important for more sustainable tyre production. Our goal is to use at least 40% renewable and recycled materials in our tires within five years. Every alternative material brings us a significant step closer to this goal.”
Recycled Reinforcement: Advancing the Use of Sustainable Steel and Polyester Yarn
Steel and polyester play pivotal roles in ensuring tyre performance and safety. Steel is present in several tyre components. In commercial and specialty vehicle tires, for example, high-strength steel cords are used to reinforce the casing, delivering exceptional durability, high load capacity, and enabling retreading. Steel is also utilised as reinforcing wires in the bead core of passenger car, commercial, and specialty vehicle tyres, running along the circumferential edges of the rubber bead to securely attach the tyre to the rim. Furthermore, steel cords are found in the tread layers of various tyre types, where they enhance puncture resistance, tread stability, and comfort, while also reducing noise, boosting fuel efficiency, and extending the range for both combustion and electric vehicles. Continental is increasingly using recycled steel in its tyre portfolio, ensuring that this shift does not compromise safety or performance.
Alongside steel, Continental is emphasising sustainability in its use of polyester textile materials. Polyester yarn made from recycled PET bottles is used to reinforce passenger car tyre casings, improving the stability of the rubber bead. Depending on the tyre size, the casing material for a single tyre can be made from up to 15 recycled PET bottles. This polyester yarn is woven into a robust textile cord that absorbs internal tyre pressure forces and maintains dimensional stability, even under high loads and temperatures. In collaboration with textile manufacturer OTIZ, Continental has developed ContiRe.Tex technology, which transforms recycled PET bottles into high-performance polyester yarn suitable for tyre casings. This process, verified by SGS, a leading inspection and certification company, reduces CO₂ emissions by about 28% in PET cord fabric for tires compared to fossil fuel-based alternatives. Continental already uses this innovative polyester yarn in standard passenger car tyres, such as the UltraContact NXT. The recycled PET bottles used in this process are sourced exclusively from regions without closed-loop bottle recycling systems.
COKOON: A Smarter, More Sustainable Bonding Technology
“When it comes to sustainability, it’s not just about the materials we switch to, but also those we deliberately forgo,” states Haufe. In collaboration with Kordsa, a global leader in textile reinforcement materials, Continental has developed COKOON, an environmentally friendly bonding standard for rubber/textile compounds. This technology enables the bonding of textile reinforcement materials to rubber compounds without the use of resorcinol or formaldehyde in the textile dip bath. To foster industry-wide sustainability, Continental and Kordsa have made COKOON available as an open-source, royalty-free solution for all tyre manufacturers and their suppliers. Interested companies are encouraged to request samples and adopt this innovative approach.
