Recycled rubber, dandelions, PET bottles among future Continental tyre mix

Various materials go into them, but car tyres are mostly made of rubber and by 2050 latest, all should be made of sustainable materials.

This is according to Claus Petschick, head of sustainability at Continental Tyres. And step by step, it is becoming apparent which raw materials will find their way into tyres. These include agricultural waste such as ash from rice husks, rubber from dandelions, recycled rubber and PET bottles.

Renewable or recycled materials already constitute 15% to 20% of a standard passenger car tyre from Continental, says the German automotive parts company. 

The tyre industry is the biggest consumer of rubber in the world, accounting for more than 70%. However, Continental employs an integrated approach, with taraxagum another approach to ensure less dependency on natural rubber grown primarily in Southeast Asia.

The manufacturer says it is also working on industrialising the extraction of natural rubber from specially cultivated dandelion plants.

Rubber fillers such as silica, which are essential to tyre assembly, will also be replaced. Silica helps to optimise grip, rolling resistance and tyre life. In the future, rice husks will be used as the source material for sustainably produced silica.

Rice husks are the hard, protective coverings of grains of rice. They are a waste product of its production and silica derived from rice husks' ash is said to be more energy efficient when used in manufacturing than that obtained from conventional materials such as quartz sand.

Plant-based oils such as rapeseed and resins based on residual materials from the paper and wood industries already offer an alternative to crude oil-based fillers in tyres.

In addition to the use of renewable materials, the company is working on using recycled raw materials in tyre production. This is intended to ensure carbon black, another crucial filler in rubber compounds, can be obtained on a large scale.

Depending on the application, season and environment, tyres have to fulfil specific requirements. This can be seen in the tread design, with passenger car tyres consisting of as many as a hundred raw materials.

Their precise composition has a major effect on their handling characteristics. The ability to deploy the various materials with their exclusive properties and interdependencies in specific ways is a complex balancing act, says Continental. Only when all the materials are ideally matched can safe, energy-efficient and durable high-performance tyres be created.

Natural rubber is essential for ensuring outstanding tyre performance. This product accounts for between 10% and 40% of the weight of modern high-performance tyres due to its strength and durability.