JAPAN: Sumitomo develops high purity natural rubber

With the recent rise in global environmental awareness, there is now an increasing demand for more fuel-efficient, resource-saving tires. In order to respond to this demand while also striving to ensure greater safety and peace of mind, it is becoming increasingly important to develop new, high-performance rubber-based materials to improve tire grip performance even further.

Responding to these demands, in 2011, Sumitomo completed the development of "4D NANO DESIGN" a new material development technology that enables the company to freely control material properties through advanced material simulation, accurately recreating the behavior of molecules at the nano-scale, and analysis. This innovative new technology has already been applied in the development of new materials using synthetic rubber, silica and carbon black, including materials used in Sumitomo's "ENASAVE PREMIUM" energy-efficient tires, which received a "AAA" rating (the highest grade available) for rolling resistance under the Japanese Tire Labeling System; Sumitomo's "WINTER MAXX" studless tires, which provide superior on-ice grip performance; and Sumitomo's all-season "SP688" fuel-efficient tires for trucks and buses.

And now, applying 4D NANO DESIGN to the improvement of natural rubber, which accounts for 28.8% (by mass) of the material in a tire, Sumitomo has learned that thoroughly removing the impurities inherent in natural rubber not only improves tire durability and wear resistance thanks to the increased bonding between rubber molecules and carbon black, but also contributes to improved tire fuel-efficiency performance by increasing the interaction between the rubber and carbon black, thereby enhancing the dispersion of carbon black at the microscopic level. At the same time, however, the removal of these impurities has also been problematic in that the process also removes the components that protect rubber molecules, making the rubber more prone to deterioration when exposed to heat (which is part of the tire production process).

With the development of "UPNR," Sumitomo has succeeded in alleviating the problem of deterioration during production through improvements in the production process. "UPNR" is an entirely new, highly purified form of natural rubber that combines both superior fuel efficiency and highly durable wear resistance.

Sumitomo Rubber Industries is currently constructing a "UPNR" production plant in Thailand and it plans to begin rolling out several tires made using UPNR, starting with new, fuel-efficient tires scheduled for launch in 2014 and beyond.

Source: Sumitomo Rubber Industries Ltd. website, Kobe, Japan; 27 May 2013

(Syed Rashid Ali, Karachi, Pakistan)