• Tyres are made from renewable raw materials
• Substantial reduction in the chemical content of tyres
• Fossil fuels largely dispensed with
• Continental - tyre prototype under development virtually free of fossil raw materials

Hanover, 27th January 2010. Car and truck tyres are made up to a large extent from natural rubber - in other words, they are produced from renewable raw materials. Working in their laboratories - their mysterious 'magic kitchens' - chemists are constantly searching for new mixtures and compounds to help them to come up with tyres which meet consumers' high demands. It was this research that enabled the experts at Continental, Europe's leading car tyre manufacturer, to substantially reduce the use of those chemicals considered potentially harmful to the environment. At the same time, tyre performance is constantly increasing.

Evaluating this development, Boris Mergell, head of material evaluation and processing car and truck tyres from Continental, sees a clear trend towards 'downsizing' in the use of chemical products, with no end in sight. In his view the 'green tyre' has already arrived in the trade. After all, natural rubber accounts for two-thirds of a car tyre, with a good proportion of this renewable raw material obtained from rubber trees in Central America. Production is in the hands of smallholders, with international corporations owning just a few plantations, so revenues from the plantations remain largely with the producers themselves.

"Our modern car tyres are highly specialised industrial products well able to handle the balancing act between renewable raw materials and essential chemical additives" Mergell comments. "Virtually every day we try out new materials and compounds in our labs in the hope of achieving further progress." His aim in this context is to do without fossil raw materials as far as possible and use recycling materials instead. Natural and re-processed oils have both been used at Continental now for over ten years. "We are working very closely with our suppliers and with independent research institutes to find a substitute specifically for those tyre ingredients that are based on mineral oil" he explains. To this end he is focusing on polymers made from biomass, process oils, different types of carbon black, mineral nano fillers and, in particular, recycling materials.. "We are currently developing a tyre prototype which does without over 90% of the fossil raw materials." For the structural supports in the tyre Continental uses recycled steel. Recycling products or products based on renewable raw materials, such as rayon, are used to replace textile cord materials.

One positive side effect is that tyres using alternative structural supports are ten per cent lighter than conventional products and so reduce a car's overall weight, resulting in lower fuel consumption.

By now almost all oils containing PAHs (polycyclic aromatic hydrocarbons) have completely disappeared from tyres. "Previously they were indispensable to ensure tyres had a long service life; they were also needed to maintain the tyre's characteristics in the wet at a very safe level" Mergell explains. "By now, though, we've been able to reduce these PAKs in all tyres, so that we come in well below the strict limits valid from early 2010." Not an easy task - one single tyre consists of around 15 different rubber compounds and each compound contains such oils. This meant that Mergell and his colleagues had to change each of the compounds, whilst maintaining the tyre's driving characteristics at the same level. Explaining the aim of his 'magic kitchen', he reveals: "The secret is the way the different compounds in the tyre interact." Each minor modification can lead to substantial variations in the overall picture. The wrong composition in the compound can already result in considerably poorer braking performance. "It is, after all, the tyre - and not the brakes - that stops the car" he states clearly. "If the composition of the tyre results in a blow-out at the crucial moment, then the best brakes are no good."

Continental's 'magic kitchen' continues to look for solutions that will make tyres safer and more environment-friendly. "Our objective here is to gain greater sustainability, both in terms of raw materials and also in production" Mergell explains. To do this, he wants to keep the use of fossil base materials as low as possible, dispense with potentially harmful compounds where possible, and make that industrial product - the tyre - safer, more durable and more economical. For him, though, one thing is certain - in terms of tyre colours, things still look black.

With sales of approximately i24 billion in 2008, Continental is among the leading automotive suppliers worldwide. As a supplier of brake systems, systems and components for powertrains and chassis, instrumentation, infotainment solutions, vehicle electronics, tyres and technical elastomers, Continental contributes towards enhanced driving safety and global climate protection. Continental is also a competent partner in networked automobile communication. Continental currently employs approximately 134,000 staff at nearly 190 locations in 37 countries.

The Passenger and Light Truck Tyres division develops and manufactures passenger car and light truck tyres for compact, medium-size and luxury cars as well as tyres for 4x4s, MPVs, vans and light trucks. In 2008, the Passenger and Light Truck Tyres division sold 111 million tyres worldwide (2007: 109 million). The division produces tyres under the brand names of 'Continental', 'Uniroyal' (except in the NAFTA region, Columbia and Peru), 'Semperit', 'Barum', 'General Tire', 'Euzkadi', 'Viking', 'Gislaved', 'Mabor', 'Matador', 'SIME Tyres' and, in Malaysia, Singapore and Brunei, 'Dunlop'. The Passenger and Light Truck Tyres division also includes the two-wheel business (motorcycle and bicycle tyres) and retail companies with more than 2,200 speciality tyre outlets and franchises in 13 countries.