Mark Duncan / AP
Today's tires are made largely from natural rubber and petroleum derivatives, but manufacturers are looking for alternatives.
If demand for tires keeps rising and raw material shortages persist, you may be driving soon on flowers and beans.
With more and more cars on the road everywhere from Beijing to Boston, tire manufacturers have been hard-pressed to overcome nagging shortages compounded by factory capacity problems, rising material costs and limited availability of natural rubber.
That’s leading manufacturers like Bridgestone and Goodyear on a search for alternative materials as diverse as soybeans and Russian dandelions.
“Natural rubber is a sustainable, renewable resource, but the problem is that the industry is growing so rapidly -- building 82 million cars a year now -- that keeping up is a problem,” said Michael Martini, president, original equipment tire sales, for Bridgestone Americas. “So we’re looking for alternatives.”
Also called India rubber or caoutchouc, natural rubber is primarily made by modifying latex collected from tapped rubber trees. Bridgestone relies on plantations in Liberia and Malaysia, but its competitors turn to resources in other parts of the world: Africa and Asia, South America and the Indian subcontinent.
Frenchman Charles Marie de la Condamine first described some of the material’s basic properties in 1736, and 34 years later British scientist Joseph Priestley discovered the material was good at rubbing pencil marks off paper, hence the name, rubber. But the big breakthrough came in 1839 when American Charles Goodyear discovered the process of vulcanization, which allowed the natural material to be used in long-lasting tires.
These days, those black donuts on your car contain a mix of compounds including carbon black, sulfur, peroxide and bisphenol, plus various petroleum derivatives and reinforcing materials such as steel, polyester and nylon. Natural rubber still makes up about 25 percent of the weight of a typical passenger car tire and even more for those used on commercial trucks.
The problem, as Martini noted, is that vehicle sales are booming. While sales in existing markets like the U.S., Japan and Europe may be relatively stagnant or declining, emerging markets are growing almost exponentially. The Chinese market alone has gone from just a couple of million vehicles annually to nearly 20 million in a decade and is expected to reach 30 million before decade’s end.
It takes about seven years for a rubber tree to go from seedling to a productive, mature plant. And finding more land for expanding plantations is another problem.
So some members of the tire industry have joined PENRA -- the Program for Excellence in Natural Rubber Alternatives -- based at the Ohio State University’s Ohio Agricultural Research and Development Center. One promising alternative is the Russian dandelion, whose root structure appears extremely good at producing a natural latex almost identical to what comes out of the hevea, or common rubber tree.
Botanists know the plant as taraxacum kok-saghyz -- not the common dandelion that’s the bane of American homeowners struggling to keep their lawns green.
“We know that there are more than 1,200 types of plants from which natural rubber could in theory be harvested, but finding one that could practically produce the quality and amount of rubber needed to meet the demands of today’s tire market is a challenge,” said Dr. Hiroshi Mouri, president of the Bridgestone Americas Center for Research and Technology.
Among those many potential alternatives, researchers have also zeroed in on guayule, a shrub native to the Southwest U.S. and Northern Mexico.
Tiremakers have also worked with synthetic alternatives to rubber. Such alternatives became crucial to the American effort in World War II when supplies of natural latex were largely cut off by Axis powers. The downside is that synthetics are largely dependent on petroleum.
The tire industry’s goal is to not only find sustainable alternatives to natural rubber but also to come up with alternatives for some of the non-renewable materials they now use, especially petroleum.
Goodyear’s Innovation Center has come up with a new method that, researchers believe, could substitute soybean oil for as much as 7 million gallons of oil each year. An added benefit is that the alternative ingredient appears to be able to improve tread life by as much as 10 percent.
"Consumers benefit through improved tread life, Goodyear gains with increased efficiency and energy savings and we all win whenever there is a positive impact on the environment,” said Jean-Claude Kihn, Goodyear's chief technical officer.
The project, funded by a $500,000 grant from the United Soybean Board, should see prototype soybean-based tires begin testing later this year. If they live up to expectations they could reach consumers by 2015, Goodyear predicted.
General Motors is trading at an all-time low, and Ford is at its lowest level in more than a year. Italy Michaeli, Citi auto analyst, and Jeremy Anwyl, Edmunds.com CEO, provide perspective.