A tyre consists of more than 200 components. Natural rubber is the main ingredient, which is complemented by synthetic rubber, metal, fibres and fillers. Among them are soot, silica and plasticizers strengthening the tyre structure additionally. Michelin worldwide employs about 6,000 people working on the ideal mixture of these components in seven research and development centres. Due to the commitment of these engineers, researchers, chemists and developers, Michelin has achieved about 10,000 patent applications for design and production. After focusing on a balance between the development goals safety, life cycle and driving behaviour – Michelin announced a superior innovation goal: Until 2050, all the tyres will have to be brought on the road in a 100-per-cent sustainable way.
Wood chips for tyre production
People responsible for Michelin stress the increasing importance of partnerships in this context. The companies Axens and IFP Energies Nouvelles are for example in charge of the so-called BioButterfly Project. Since 2019, the partners together with Michelin have been working on the production of bio-based butadiene. This biomass consisting of wood, rice husks, leaves, corn stalks and other plant wastes is to replace butadiene based on petrol. According to company information, 4.2 million tons of wood chips could annually be processed to produce Michelin tyres.
In November 2020, Michelin signed the partnership with the Canadian company Pyrowave with the following aim: Recycled styrene is to be produced from plastics one can find in packaging, yoghurt cups or insulation panels. Styrene is an important monomer that is not only used to produce polystyrene but also for synthetic rubber for tyres and several other consumer goods.
Michelin started a further cooperation with the French start-up Carbios, which developed a process using enzymes to split PET plastic waste into its original monomers. These can be recovered endlessly and reused to produce new PET plastics. One of these recovered plastics is the polyester yarn used in tyre production. “About four billion plastic bottles could potentially be recycled into tyres”, explained Michelin.
Plans for tyre recycling plant
Finally, Michelin announced that together with the Swedish company Enviro the construction of the worldwide first tyre recycling plant was launched. Enviro developed a patented technology to recover soot, pyrolysis oil, steel, gas and other valuable materials from old tyres. Thus, raw materials contained in the tyres could be recycled and reused in different rubber-based production steps.
The people responsible also mentioned the European BlackCycle Project as further example for the support of the recycling economy. The Michelin group coordinates the consortium, and the European Union is responsible for finances. A total of 13 public and private partners came together to develop processes to produce new tyres based on old ones.
