Continental Conti GreenConcept tyre debuts in Munich – uses over 50% sustainable materials, and is retreadable.
Continental Concept for Sustainability and Retreading
Continental has managed to take the lead in car tyres and sustainability with the unveiling of the Conti GreenConcept at this year’s IAA Mobility (Munich Motor Show). The tyre is still at concept stage, so perhaps there is still a way to go before it hits the roads. The project aims to highlight the sustainability of new tyres. We refer our readers to the article in Tyre and Rubber Recycling 2021/3 about Sustainability and Tyre Manufacturers.
Continental claims that the plan is to reduce resource use throughout the tyre’s lifespan – from sourcing materials, extending the lifespan and eventually recycling. It is interesting that Continental also refers to this car tyre as being retreadable – not a feature that car tyre manufacturers have focussed on for many years, if ever. Does this suggest a longer-term goal for Continental in terms of tyre recovery and retreading?
According to Continental, more than 50 per cent of the raw materials used to make the Conti GreenConcept come from either renewable sources or from recycled sources. The company says it aims to fully transition to use sustainable raw materials by 2050. It also defined “sustainable” as being materials that originate from closed-loop cycles, have no harmful effects on people or the environment, responsibly sourced and climate-neutral across their entire supply chains.
35% of the eco-friendly tyre concept is made from renewable materials, including natural rubber from dandelions, silicate from the ash of rich husks, as well as vegetable oils and resins, all of which reduce the dependence on materials based on crude oil.
The company says its global tyre-making plants are already making widespread use of materials such as recycled rubber or vegetable oils. Additionally, it is one of the companies looking at Russian Dandelion as a source for Taraxagum as a substitute for Latex.
17% of the Conti GreenConcept is made up of recycled materials like reclaimed steel and recovered carbon black. Furthermore, in an industry first, polyester from recycled PET bottles is also being used as part of the company’s ContiRe.Tex technology, which it says will be gradually rolled out from 2022.
Getting rubber to adhere to steel requires a special coating, and the same is true with the textiles used in car tyres – these bonding materials have not always ben eco-friendly. Continental has worked with Kordsa to develop Cokoon dip technology, which enables eco-friendly bonding of textile reinforcements with rubber compounds. The open-source technology has been made available to all tyre industry players on a free-of-charge basis since 2019.
The Conti GreenContact is also 40 per cent lighter than conventional tyres, weighing in at just 7.5 kg. This was made possible by an optimised tread pattern, a special sidewall and a new casing design with a weight-optimised core.
Continental also engineered it so that it can be retreaded multiple times, with minimal investment in terms of time and materials. A green-coloured tread baseline indicates the transition from tread to casing.
Undamaged casings can be retreaded several times according to Continental, and as the tread compound is made from 100% Taraxagum natural rubber derived from dandelions, if a tread is renewed three times, for example, this halves the amount of material used for a casing as seen in terms of its total mileage.
Of course, this would suggest that the retreading material would also be Taraxagum based- thus either opening a new avenue for retread materials suppliers, or, ensuring that the retreading might be done by some future in-house car tyre retread operation at Continental.