Discover the innovative process that uses waste cooking oil and circular resins to produce greener tires, environmental goals and technical challenges

Growing pressure for ecological transition is requiring the automotive and materials industries to develop new solutions to reduce environmental impact. Among the most challenged sectors is the tire industry, where research into sustainable raw materials is crucial.

Historic tire manufacturer Continental recently announced a major innovation: the introduction of synthetic rubber made partly from used cooking oil. The goal is to reduce emissions, reuse otherwise difficult-to-dispose waste, and increase the share of recycled and renewable materials in its compounds.

Sustainability in the tire sector

Tires are made of dozens, sometimes hundreds, of raw materials: natural rubber, synthetic rubber, resins, oils, additives, metallic fibers, and textiles. Traditionally, many of these components come from fossil fuels or intensive production methods with a significant impact on the carbon cycle. In this context, the sustainability challenge requires both a reduction in "virgin" materials and the ability to reuse waste materials to avoid increasing the environmental impact of the finished product.

What is meant by synthetic rubber from alternative sources

Synthetic rubber is a key component of the tire's tread, body, and other elements, ensuring elasticity, heat resistance, dimensional stability, and adaptability to climatic conditions.

Typically, it is made from petroleum-derived polymers. Alternative sources include pyrolysis oils (including those from used tires), used vegetable oils, and certified bio-based resins. The use of alternative raw materials requires that the polymer's molecular structure and chemical-physical compatibility do not compromise safety, durability, wet grip, rolling resistance, and high-temperature resistance.

The role of used cooking oil in the new mix

Used cooking oil, also known as WCO (Waste Cooking Oil), is an organic waste that can be collected and sent for purification and transformation. Continental has identified WCO as a useful alternative material for the production of synthetic rubber. After purification, deodorization, and removal of unwanted elements, used oil can provide molecules useful as precursors or as a raw material for bio-circular additives. When incorporated into the compound, it helps reduce the proportion of fossil materials, lower the carbon footprint, and valorize waste that would otherwise be destined for disposal.

Circular resins and sustainable additives: characteristics and functions

In addition to used oil, Continental uses certified circular resins and innovative additives. Circular resins are produced from renewable sources or waste materials and meet biocompatibility, durability, and mechanical performance criteria equivalent or comparable to those of conventional resins.

Additives, which serve to modify properties such as elasticity, oxidation resistance, thermal stability, are also being rethought: sustainable versions must support vulcanization, maintain performance over time, and not cause negative side effects (e.g., premature degradation, release of harmful substances).

Certifications and mass balance in the production chain

Once these alternative raw materials are introduced, a rigorous traceability system is required.

With this approach, a certain percentage of the finished product is designated as sustainable, according to standards such as ISCC PLUS certification. This allows for documentation and verification of the origin of alternative raw materials, including used cooking oil and circular resins, making the environmental commitment transparent to consumers and regulators.

Performance and safety: mandatory criteria

Any innovation in tire compounds must ensure that safety, durability, and performance on the road are not compromised. Wet braking, aquaplaning resistance, rolling resistance, mileage, and stability at both high and low temperatures are parameters that cannot be sacrificed.

Continental claims that tires made with synthetic rubber from used oil, resins, and sustainable additives maintain performance equivalent to previous standards, thanks to wet and dry tests and accelerated aging simulations. Heat and wear management also remain key, as these determine the safety and environmental impact of the tire throughout its life cycle.

Continental's goals for 2030

The company's strategic plan includes progressive increases in the share of fully sustainable materials. By 2024, the percentage of renewable and recycled materials was already around 26-28%. The goal is to reach at least 40% by 2030. This involves not only the use of used oil and bio-certified resins, but also the optimization of production processes, collaboration with suppliers of alternative raw materials, and the dissemination of efficient recycling technologies.

Environmental, circular and economic implications

Using used cooking oil and other recycled materials in tires has multiple benefits. First, it reduces organic waste that ends up in landfills or requires costly disposal processes. It also reduces dependence on fossil fuels, contributing to the mitigation of greenhouse gas emissions.

From a circular perspective, it addresses multiple fronts: production, disposal, and recycling. Economically, if the waste oil collection and purification chain is optimized, the costs of this alternative raw material compared to petroleum derivatives can be reduced, especially given the rising cost of fossil fuels. However, there are also challenges:

- standardization of the quality of used oil

- certification

- transport

- compatibility of production processes

- market acceptability.

Conclusion

The transformation of used cooking oil into synthetic rubber for tires represents a concrete step toward a circular economy applied to the mobility sector. With circular resins, sustainable additives, rigorous certifications, and ambitious targets, Continental demonstrates how innovation and environmental responsibility can coexist without compromising safety or performance. For companies, regulators, and consumers, this opens up a path where every part of the chain—from household waste to the finished product—can contribute to reducing climate impact and building a greener future.

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