In a bid to achieve a 100pc sustainable materials production of their tyres by 2050, Continental Tyres are looking into agricultural waste to source alternative filling materials, and weeds for substitution of natural rubber, writes Brian Byrne. Up to 100 different materials go into the construction of a modern tyre, with natural rubber being anything between 10pc and 40pc of the weight of the tyre. Agricultural waste materials like the ash of rice husks, and recycled plastic bottles, are among the materials being tested by the company, the latter can be turned into polyester yarn for tyre casings. Specially cultivated dandelions are being tested as alternatives to natural rubber. Along with these ideas, tyre makers are increasing the amount of recycle activity to separate rubber, steel, and textile from old tyres, as well as the very important carbon black using a process called pyrolysis.