better tires will save fuel, cut emissions

Long a leader in the butyl rubber industry, ExxonMobil Chemical will launch a new product to smooth your ride.

This article originally appeared in the Lamp, 2007 — Number 3

ExxonMobil Chemical Company will commercialize a new product that may revolutionize the tire industry.

A blend of synthetic rubber and nylon, the product allows for lighter and more durable tires that roll easier and maintain proper air pressure far longer than conventional tires. These characteristics translate to vehicles that use less fuel and, thus, create fewer emissions.

"According to the Department of Energy, underinflated tires waste about 1.2 billion gallons of fuel a year in the United States alone," says Mike Brownlow, butyl sales and marketing manager for ExxonMobil Chemical. "Consumers can help reduce fuel usage by checking that they have the proper tire pressure more frequently — and a minimum of once a month is recommended. However, no matter how often you check your tires, a tire that holds air better will have less underinflation on average, thereby using less fuel."

The new product features the company’s Exxpro specialty elastomers (an elastomer is a rubber, typically used to impart elasticity to a product), which are isobutylene-based materials similar to butyl rubber, used in hundreds of products from footballs to conveyor belts. Butyl rubber and its younger cousin, halobutyl rubber, prevent air leakage much better than natural rubber or other traditional synthetic elastomers, which is why they have been used in inner tubes and tires for more than a half-century. ExxonMobil researchers invented butyl rubber in the 1930s, and the company has long been a technology leader in the butyl industry. ExxonMobil Chemical makes several types of butyl rubber, supplied to tire manufacturers and other customers worldwide.

Building a better mousetrap
Over the past several years, ExxonMobil scientists developed a revolutionary new form of synthetic rubber, brand named Exxpro specialty elastomers. The material can be dynamically blended with nylon to form a unique alloy that combines the flexibility and elasticity of rubber with a low-air permeability. The result is — simply put — a "better mousetrap."

"This new material is superior in many ways," says Howe-Yong Hong, butyl marketing manager for ExxonMobil Chemical. "Most passenger tires today have a halobutyl innerliner that’s about 0.8 mm thick and weighs about 2.2 pounds (1 kilogram). Our new material can replace that design with a liner about as thin and light as a plastic bag. The weight reduction is nearly 80 percent, and the new liner does a far better job of preventing air leakage."

Studies show more than 25 percent of U.S. vehicle tires are substantially underinflated, a condition that not only wastes fuel, but also is unsafe. An underinflated tire generates heat and leads to uneven wear, conditions that can cause tire failure. That’s why it’s important for motorists to regularly check tire pressures to ensure proper inflation.

ExxonMobil and Yokohama Tire Company of Japan developed the new product, which is called Exxpro Nylon DVA. Over several years, the companies conducted research with alloys of the new elastomer materials and their use in tubeless tires. Several tire manufacturers are now testing the new material and evaluating its application in their respective product lines.

Saving energy while expanding production
Producing isobutylene-based synthetic rubber is a complex and energy-intensive process. Butyl rubber and Exxpro specialty elastomers are manufactured in frigid conditions approaching minus 150 degrees Fahrenheit (minus 101 degrees Celsius). Achieving such low temperatures consumes a tremendous amount of energy. This has recently changed, however.

"ExxonMobil’s research and technology organizations developed an amazing new process that allows us to manufacture butyl rubber and Exxpro specialty elastomers in a substantially warmer environment," says Brownlow. "That is a huge breakthrough and is possibly the most significant development in the butyl industry in nearly 50 years. It will allow us to substantially increase our production capacity at the manufacturing sites with the technology enhancement. So, we’re increasing production while saving energy and lowering costs."

Pensacola manufacturing plant
Exxpro specialty elastomers manufactured at Baytown will be shipped to Pensacola, Florida, where ExxonMobil Chemical is building a manufacturing plant that will blend the products with nylon. The resulting material, known as a "dynamically vulcanized alloy," can be made into sheets of film for use in tire innerliners. The Florida facility will be completed in 2008 and will supply customers worldwide.

"ExxonMobil has a long history of research and development of butyl-based products," says Art Sullivan, ExxonMobil Chemical’s Butyl Polymers Global Business vice president. "Our new Exxpro specialty elastomers are just the latest innovation to come from our industry-leading research and technology organizations."

Sullivan stresses that ExxonMobil will continue to manufacture and invest in butyl, which has been a staple of the tire industry for more than a half-century. "World demand for tires continues to grow, which means demand for halobutyl is also growing," he says. "That’s why since 2000 we’ve made significant investments in manufacturing facilities at Baytown that have more than doubled our butyl production capacity at this site. Now we’re adding to that capacity so we can expand the supply of our Exxpro specialty elastomers. We’ve also boosted our production capacity in Japan and France. These expansions demonstrate ExxonMobil’s continued commitment to supply customers in the global tire industry. We back that commitment with 70 years of experience in butyl rubber research and development, services and product know-how."