Continental's search for innovative materials has extended even as far as the humble dandelion, a plant that can be used to manufacture rubber – for tires that are especially environmentally friendly. Materials researcher Carla Recker wants to help make the dandelion a breakthrough material.
The tires themselves are black and round, just like any other "normal" tire. The dandelions subtly embossed on the sidewalls are the only clue to the materials origins. That, and of course the yellow-green emblem with the brand name "Taraxagum," derived from the plant's botanical name. At the Continental technology center in Stöcken in Hanover, Carla Recker gazes with pride at the tire on display in the conference room, a tire which was produced just two weeks ago at the Aachen plant. Carla, who has a doctorate in chemistry and is responsible for materials chemistry at Continental, was there in person as it was released from the mold: "Even the day before we weren't quite sure whether it would work." No surprise then, that Carla did not sleep much that night. For the prototype, her colleagues spent weeks extracting rubber from dandelion roots. And for months they experimented in the laboratory to find out how to use the new material to replace natural rubber from the rubber tree, which is found in every tire alongside synthetic rubber. On top of this came a huge amount of administration work, because Carla has been working with the Fraunhofer Institute for Molecular Biology and Applied Ecology at the University of Münster since 2007.
All the hard work has paid off and the first dandelion tires have now "hit the streets," even if the street in question is at this stage just Continental's own test track. Production of the new tire will not start before 2020 at the earliest. Carla Recker can't hide her enthusiasm and her eyes light up as she relates one detail after another. First, some information about dandelions themselves: Through cultivation, the type of dandelion used by Continental, known as the Russian dandelion, has been modified by the Fraunhofer researchers so that it provides more sap and can be grown like a field crop. The vision is to obtain dandelion roots as tall as sugar beet. This is to be achieved by growers in Bavaria and Saxony who will grow dandelions on test fields. "We'll have to wait from growing season to growing season, and hope that between the seasons there are no floods or other catastrophes," says the 49-year-old with a grin, who looks a lot younger than her age in jeans and sneakers. Alongside her job at Continental, Carla studied environmental technology, a subject which now stands her in good stead when suddenly confronted with biology and agriculture.
Carla's team received official recognition for their work when the dandelion project received the GreenTec Award, Europe's most prestigious environmental and business accolade. "That was certainly a career highlight." beams Carla. "Otherwise the success of my work tends to remain hidden, even if it is part of so many products." Jokingly, she says she'd sometimes like a stamp saying "Material expert inside."
In fact obtaining rubber from dandelions is nothing new: the first patent for the process was issued in 1905. Carla Recker's colleagues also found two folders on dandelions in the Continental archives. "But research was stopped, because it was not economically viable," she explains. Today, things look a little different: "We made a business case and according to current data, it's viable." In addition, the dandelion is an undemanding plant that can also be grown in a Northern European climate and on poor soil. This will save on long journeys from tropical rubber tree plantations, and there is no competition with the cultivation of domestic foodstuffs. Further environmental benefits include the fact that dandelion rubber could meet the growing worldwide demand for rubber without needing to sacrifice any more rain forest for the planting of rubber trees. This will reduce the carbon footprint and increase bio-diversity; two factors that convinced the GreenTec jury too.
Truck tires are potentially a massive market for the new material: truck tires weigh 70 to 80 kilos, of which 30 to 40 percent is natural rubber, a much higher figure than for car tires. However, Carla Recker does not believe that one day all the rubber in Continental tires will be obtained from dandelions. For reasons of economy and safety, tires must be made from a combination of different raw materials – but with maximum sustainability. "And dandelions will really help with this."
A pilot system is currently being built that can be used to manufacture dandelion rubber by the ton. "It's still very early days," explains Carla. Considerable staying power will be needed, together with the strong backing of the company. Ultimately, such long-term projects are extremely unusual in the industry. As the project manager, Carla is pleased that "everyone is right behind us." No doubt her fascination for dandelions and the enormous energy she radiates have been key in persuading them.