Pirelli tests UHP tires derived from guayule

MILAN, Italy—Pirelli Tyre S.p.A. recently tested an ultra-high-performance tire made with rubber derived from guayule, culminating a two-year research and development initiative Pirelli embarked on with Italian materials supplier Versalis.

Pirelli said in general the test tires “demonstrated the same performance as the equivalent tires made with synthetic polymers from oil-derived products” in a variety of extreme usage simulations, including wet road surfaces.

Fabrizio Sanvito, project management and technical benchmark at Pirelli, said, “The track testing phase of our guayale rubber tires has been more than positive. The choice of a high-performance car to carry out these tests was dictated by the need to place the biggest possible demands on the tires and extract the most meaningful results.

“After the success of this first phase, we are now assessing the possibility of trying out these prototype tires in winter conditions.”

Pirelli tested the tires using a Maserati Ghibli four-door sedan at two testing facilities in Italy—its own near Vizzola and Fiat Group's near Balocco. Powered by a 3-liter twin-turbo V6, the Ghibli is capable of speeds up to 165 mph and 0-60 mph acceleration in 5.6 seconds.

Since signing the R&D pact with Versalis—a unit of Italy's Eni S.p.A. energy company—in 2013, Pirelli's researchers have studied the characteristics of guayule-derived rubber closely in laboratory conditions, in order to assess how it would translate to road use.

The program benefited from research Versalis has carried out on technologies used for the extraction of rubber, as well as the resinous nature of the plant, Pirelli said, which yielded a material that was compatible with the non-elastomeric parts that make up a tire.

Versalis' research is part of a development program looking at ways to incorporate guayale usage throughout industry, Pirelli said, starting with experimental crop growing in southern Europe and expanding into various technologies aimed at extracting the natural rubber with the aim of using it to make tires.

Guayule is often described as a desert shrub that typically grows in arid climates. It is not a food crop and can be cultivated with little water and no pesticides, making it a viable alternative to the Hevea Brasiliensis rubber plant, Pirelli said.

Substituting petrochemical polymers with alternative and renewable primary materials is a key objective for Pirelli's research division, the tire maker said, which has been focusing on sustainable mobility solutions for many years.

Another example of this effort is the use of silica obtained from rice husks, the non-edible part of rice that is usually destined to be burned.

“For Versalis, guayale is the perfect bio matter on which to develop a genuinely integrated bio refinery,” said Sergio Lombardini, R&D and technology innovation director of Versalis.

“Using a technological platform aimed at integral use of guayale, it's going to be possible to produce tires and resins that have an application both in the automotive and construction industries, as well as making use of other constituents of this bio matter that can be used in the pharmaceutical and health care sectors.

“The collaboration with Pirelli can only increase the chances of success in this innovative project with massive potential.”