Rubber Journal Asia Green Rubber
New biorubber tyres with a greener footprint R&D efforts and partnerships are keeping pace with the clamour for renewable-
sourced rubber for tyres, says Angelica Buan in this report.
From guayule to soy beans
ncreasing environmental and energy concerns are prompting tyre makers to partner with materials science experts in discovering the alchemy of biobased rubber alternatives. Perhaps the most prominent and much anticipated green rubber breakthrough is that of the desert shrub guayule rubber. The high-yield renewable feedstock is expected to unchain the industry from the supply and price volatility of Hevea-sourced natural rubbers. The five-year US$6.9 million-Biomass Research and Development Initiative (BRDI) grant for guayule rubber research has been completed. The study consortium led by Cooper Tire & Rubber and partners (Clemson University, Cornell University, PanAridus and the Agricultural Research Service - USDA) has announced that the 100% guayule-based concept tyres have “overall performance at least equal to tyres made with Hevea and synthetic rubber.”
Bridgestone and Goodyear worked with the the United Soybean Board to develop soy oil-based tyres
the Missouri-based farmers-producers organisation, the United Soybean Board (USB), the US tyre maker created a tread compound, or formulation, using soybean oil, which is naturally derived, cost-effective, carbon-neutral and renewable. The soybean oil in tyres enables Goodyear to keep the rubber compound pliable in changing temperatures – such as in dry, wet and winter conditions – a key performance achievement in maintaining and enhancing the vehicle’s grip on the road surface. Goodyear’s tests have shown rubber made with soybean oil mixes more easily in the silica-reinforced compounds used in manufacturing certain tyres. This also improves manufacturing efficiency and reduces energy consumption. USB shared in an earlier report that soybean oil in tyres can potentially increase tread life by 10% while reducing the use of petroleum-based oil. Moreover, rubber compounds made with soybean oil blend more easily with the silica used in building tyres, thus helping to improve plant efficiency and reduce energy consumption and greenhouse gas emissions. In 2012, Japanese tyre maker Bridgestone also unrolled its Firebrand concept tyre containing 10% or almost 41 l of soybean oil. It explained that one bushel, or an equivalent of 35 kg, of soybeans yields almost 5 l of soy oil. It can be recalled that Goodyear also incorporated other biobased materials into its tyres. In 2015, the Ohiobased company forged a supply agreement with Yihai Food and Oil Industry in China for silica derived from rice husk ash, for use in a consumer tyre it produces and sells in China.
Cooper built more than 450 tyres, replacing various components made with Hevea and synthetic rubber with guayule and testing each for overall performance, to create the industry’s first all-guayule concept tyre. Now, the industry is needed to grow the plants and create largescale manufacturing operations to produce guayule for use in the tyre sector, says the firm
Performance is only half the good news. The guayule rubber tyre is environmentally-friendly too. It has been found to chalk up between 6% to 30% lower emissions in ten different life cycle environmental and energy impact categories, compared with a conventional tyre. For Goodyear Tire & Rubber Company, soybeans are magic seeds for its new rubber tyres. With support from
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