Tyre-maker Continental has joined with fibre specialist OTIZ to use reprocessed polyester from recycled polyethylene terephthalate (PET) bottles to construct the carcass of auto tyres.

This replaces the need for conventional polyester yarn. The average-size tyre consumes 400 grams of new yarn but the recycling process means about 15 PET bottles can supply the same amount of polyester without any change in strength, toughness, and thermal stability.

Continental now expects the recycled polyester to be used in tyre manufacture from next year.

The tyre-maker and fibre specialist and textile manufacturer OTIZ said that the recycling process can be performed without the previous intermediate chemical steps that had been required to ensure the polyester yarn was functional for high mechanical usage.

Continental said that laboratory and tyre tests have shown that the recycled raw material fibres perform equally well as new fibres.

The recycling process includes the sorting of the bottles, the removal of the caps and the  mechanically cleaning of the bottles.

They are then mechanically shredded, melted down, and granulated, then undergo solid-state polymerisation and a modified spinning process. 

Continental said that recycling was becoming increasingly important in the design, development and production of its tyres.

“By 2050 at the latest, Continental aims to successively use 100 per cent sustainably produced materials in its tyre products,” it said in a statement.

“Resourcing PET materials from recycled substances brings us one step closer to Continental’s future in the circular economy and puts us at the forefront of sustainable innovations.”

By Neil Dowling