Bridgestone looks to desert for rubber
Guayule plant a natural source for car, truck tires
Ever since the first European explorers crossed the Atlantic and saw Aztec children tossing rubber balls, an idea has persisted:
Why not make something besides toys out of that stuff ?
Three centuries later, Nashvillebased tire manufacturer Bridgestone Americas Inc. is trying to do just that — turn natural rubber inside desert shrubs into new tires for cars and trucks.
Bridgestone recently announced a deal with polymer maker Versalis of Milan to develop a sagebrush-like plant called the guayule (pronounced whyyou-lee) for commercial harvests of rubber.
“We’re trying to create an industry that does not exist in North America today,’’ said William Niaura, Bridgestone Americas’ director of new business development.
At the dawn of the automobile age, American industrialists tried to turn the same wild plant into a reliable source of rubber but eventually fell short. Rubber tree plantations proliferated in Brazil, Indonesia, Malaysia and other tropical terrains.
Experts say it’ll be a few years before desert rubber can begin to replace the 44 pounds of tropical rubber used in tires on the typical midsize sedan. But the global auto industry is searching hard for an alternative supply. Synthetic rubber derived from petroleum chemicals is common in tires, though engineers prefer natural rubber for its strength, elasticity and steering ability in specific places such as the tread and sidewall.
“The higher loading that a tire sees, the more natural rubber it is going to have,” Niaura earlier told trade journal Chemical & Engineering News.
Demand has climbed for natural rubber. But parasites threaten Brazil’s vast rubber plantations. And in Southeast Asia, environmentalists say rapid expansion of rubber plantations to meet surging demand has diminished water quality.
Looking at plans to develop 21 million acres of Asian jungle into rubber tree plantations over the next decade, scientists at the University of East Anglia in Norwich, England, in 2015 told of “catastrophic biodiversity impacts, with globally threatened unique species and ecosystems all put under threat.”
Now the rubber industry is abuzz with efforts such as the Bridgestone-Versalis venture to find a new rubber supply to ease development pressure in Asia and Brazil.
Last year, General Motors Corp. announced partnerships with the world’s four largest tire makers — Bridgestone, Continental, Goodyear and Michelin — to develop what the Detroit automaker calls “sustainable” natural rubber.
“GM committed to source sustainable natural rubber for all of its tires in the future,” said Nick Richards, GM product development, purchasing and supply chain communications manager, according to the Feb. 5 edition of the trade journal Rubber & Plastics
News. “While we stated that we will develop a set of purchasing requirements, our intent was that the entire automotive industry will join in the movement and together help transform the rubber supply chain.”
Key to transformation is guayule, a flowering perennial in the aster family native to deserts in the United States and Mexico and transplanted to arid Europe near the Mediterranean Sea. In Japan, Bridgestone has made experimental tires of guayule rubber. Pirelli, the Italian tire maker, has done so in Europe. Michelin is exploring the possible extraction of rubber from a plant called the Russian dandelion.
No tire maker has yet relied on dandelions or guayule. The industry depends on the tropics for rubber supplying the 3 billion tires made annually. Four rubber trees tapped regularly for a year produce the 11 pounds of natural rubber found in the typical car tire. The same amount of desert rubber would re- quire about 100 guayule shrubs planted a foot apart and harvested once a year, Niaura said.
Guayule grown on about 500,000 desert acres — an amount of land about a tenth of the size of the Mississippi Delta southwest of Memphis — might displace about 25% of the tropical rubber, Niaura estimated. Rather than cultivate themselves, most tire makers envision buying the product from growers.
Harvesting desert rubber has one notable advantage. Russian dandelions and rubber trees like richer land good for food crops, while guayule can survive on 8 inches of annual rain falling on meager soil, Niaura said.
Bridgestone operates research stations in Arizona for cultivating the wild plant. It has partnered with the University of Arizona on research and development. Scientists from the U.S. Department of Agriculture’s Agricultural Research Service also have pitched in.
Efforts now are focused on developments such as using genetics to identify specific plants best suited for cultivation as well as finding markets for the resin and woody material left after the rubber has been extracted, Niaura said.