NR/silica technology to lower truck tire rolling resistance

Hanover, Germany — Evonik Industries AG has developed a silica/silane technology for use in natural rubber compounds it claims could help reduce rolling resistance in medium truck and bus tires.

Evonik claims testing shows using its silica/silane technology could yield fuel savings of as much as 8% versus traditional carbon-black reinforced NR compounds.

The technology is also claimed to reduce braking distances, leading to greater driving safety on wet or snow-covered roads.

Silica's effect on rolling resistance in passenger tires is well documented, Evonik noted, when used in compounding with synthetic rubber. It's claiming the use of its Ultrasil 91000 GR precipitated silica reinforcing filler is "particularly suitable" for use in truck and bus tires.

"So silica/silane technology, especially when used in green tires for buses and trucks with high fuel consumption levels, is making an important contribution to climate protection," said Jens Kiesewetter, Evonik's head of technical service for rubber silica.

"And that in anticipation of the recently concluded EU agreement on targets for CO2 reduction for trucks," he added.

Evonik noted that despite its high specific-surface area, Ultrasil 9100 GR is incorporated into and dispersed in the natural rubber compound relatively easily. The resulting compound offers improved abrasion resistance, which in turn yields better mileage performance.

This is particularly critical, Evonik said, because of the long distances truck/bus tires cover and the variations in infrastructure they encounter, which subject these tires to particularly heavy loads. Silica-reinforced compounds also improve driving safety through shorter braking distances, even on wet road surfaces, Evonik stated.

"Feedback from the market tells us that demand for green tires continues to be very high, thanks to their advantages," Bernhard Schäfer, head of rubber silica, said.

"Their use in buses and trucks particularly is still quite new and is attracting great interest."

In addition, Evonik noted it is "fully on track" to expand tire silica capacity at a plant in Adapazari, Turkey, including adding capacity for the Ultrasil 9100 GR precipitated silica reinforcing filler and Ultrasil 5000 GR, for optimizing wet and winter properties of tires.

Launched in response to "growing demand for innovative silica," the expansion project will primarily serve customers in southeastern Europe and the Middle East. Designed to increase capacity by 40,000 metric tons per year, the project is expected to be completed in late 2019.