The commercial availability of Sumitomo’s Enasave 97, albeit in small volumes, has demonstrated the feasibility of producing tires containing very little in the way of fossil fuels. Introducing completely or nearly fossil fuel-free products in greater quantities is a goal held by all tire majors, and Continental’s head of material and process engineering has shared some details about the German tiremaker’s progress in this direction.
Dr. Boris Mergell reports that today’s standard tires contain about 45% non-oil based raw materials, and Continental’s chemists have helped the tiremaker increase this percentage by replacing fossil oils with rapeseed oils and polyester with rayon as reinforcement within the tire’s casing. At the same time, recycled tire rubber increasingly serves as a substitute for synthetic and natural rubber in tires. Continental suggests it may have a 100% natural raw materials tire ready by 2020, but this is easier said than done.
“Not all raw materials in tires can simply be replaced by renewable materials,” explains Mergell. “In many cases, such materials have a negative impact on braking performance or rolling resistance – and we will not accept any compromise here. Also, the widespread replacement of fossil materials with renewable raw materials is not always a solution since it requires acreage that might already be used in food production.”
Nevertheless, Mergell sees the introduction of tires made with sustainable materials as achievable within this coming decade. “We still need to conduct numerous tests on materials and in our process engineering to make significant progress,” he says, but adds that the introduction of “green tires” is coming in the next five years or so.
Technologies currently under investigation at Continental include rubber extraction from dandelion, which presents a promising potential replacement for rubber extraction from hevea trees. Mergell shares that since dandelion is grown on fallow fields in Europe, it would neither compete with food products nor require long distance transportation to European tire plants. Further materials that can potentially be used in tires include plasticizers and resins, either acquired from renewable resources or recycling facilities. (Tyres & Accessories)
