Making Tires From a Desert Shrub Found in the U.S.

Source: By DIANE CARDWELL, New York Times • Posted: Thursday, August 20, 2015

A guayule plant at Cooper Tire’s test center. The company expects to make a complete tire from guayule-derived parts by 2017. Credit Matthew Busch for The New York Times 

For years, tire industry executives, as well as government officials and scientists, have sought a domestic source for natural rubber to escape the price fluctuations of imports and, more recently, to avoid petroleum, which is used to make synthetic rubber.

Now, Cooper Tire and Rubber Company has reached an important milestone in that effort, and is expected to demonstrate tires this week with components made of rubber from the guayule plant, a desert shrub cultivated in the Southwest.

Cooper Tire executives, who are leading a consortium to develop and market the substance, say they expect to make a complete tire from guayule-derived parts by early 2017. The group includes PanAridus, which is growing the plants and manufacturing the rubber, as well as Cornell and Clemson Universities.

“In two years,” said Mike Fraley, chief executive of PanAridus, “we’ve traveled from test tubes to tires.”

The effort is one of several underway as companies work to develop a domestic guayule industry.

Bridgestone opened a bio-rubber research and manufacturing center last year and Ford has a partnership with Ohio State University to help use the substance in automotive applications.

Another start-up, Yulex, is also growing guayule and making rubber for a variety of products, including a special line of wet suits at Patagonia. Yulex had previously worked with Cooper Tire on the development of the guayule plant-based polymers before being replaced by PanAridus.The Cooper Tire program is part of a $6.9 million Biomass Research and Development Initiative grant under a joint effort by the United States Agriculture and Energy Departments to spur the development and analysis of feed stocks, biofuels and bio-based products.

In addition to producing a latex that can be processed into rubber, the guayule plant produces resin that can become adhesives, flavors, fragrances, and biofuel, and fibrous matter that can become biofuel or construction materials.

Though the biomass research project began relatively recently, the nation’s interest in guayule reaches back to the beginning of the last century. In the early 1900s, historians say, American industrialists began producing rubber from guayule in Mexico, but the Mexican Revolution put an end to commercial production there and the Depression later halted the efforts that had moved to the United States.

Interest in guayule as an alternative returned during World War II, when the Japanese cut off access to hevea-based rubber, spurring the Emergency Rubber Project, which involved thousands of scientists, technicians and laborers, some of them Japanese internees. Interest fell off again with the end of the war and the development of synthetic rubber, but was rekindled after the oil crisis of the 1970s, which led to a new round of government-supported research.

Tire executives say that global demand for tires, which use as much as 70 percent of the world’s rubber supply, will expand as less developed nations industrialize, requiring roughly 21 million additional acres of hevea, the source of natural rubber, by 2024.

Although guayule grows much faster than hevea, hevea’s rubber has certain attributes that have proved tricky to replicate, including resistance to cracking and the ability to prevent high heat buildup. Cooper has so far managed to make a number of tire components with 100 percent guayule, and said work for all of the components that would be replaced is either complete or in the advanced stages.

“It’s easy to replace a little bit of the rubber in a component,” said Howard Colvin, a senior scientist at Cooper. “When you replace all of it, everything shows up.”