Before thousands of spectators at the world's largest air show, Airbus SAS introduced its newest airliner, the A350 XWB. The twin-engine wide-body flew over Le Bourget Airport in Paris earlier today, one week after its maiden flight. Airbus has secured more than 600 orders for three versions of the aircraft, according to company documents.
Beneath the blue and white company livery, the A350's airframe is composed of 72 percent lightweight materials like aluminum and titanium alloys. The most important material, however, is carbon fiber reinforced polymer, making up more than 53 percent of the airframe.
The increase in lightweight components in aircraft signals how commercial aviation targets have shifted from larger, farther, faster to cheaper, quieter, more efficient. Though the materials themselves are not new, the technology and the commercial demand for them have recently aligned. That makes advanced materials like carbon fiber essential to staking out a competitive edge in an international arena.
The A350 will go toe to toe with Boeing Co.'s incumbent 787 Dreamliner, already in service with nine airlines. Like the A350, the 787 also uses substantial amounts of carbon fiber in its airframe to enhance fuel economy and cut operating costs for airlines.
The material is making inroads into other sectors as well. Stronger, stiffer and more durable than most metals and at a fraction of the weight, carbon fiber enables a suite of energy-efficient and clean technologies from wind turbines to cars in an era of turbulent energy prices and a changing climate.
Now governments around the world are vying for a stake in the global carbon fiber market. The United States in particular is aiming to retake the lead it once held in advanced materials, playing to its strengths in research and development.
An American company, Union Carbide, initially developed carbon-fiber-reinforced polymers in 1958, but today China, Japan and Europe manufacture the vast majority of this material.
Trying to recover a U.S. lead
As part of a new manufacturing initiative to boost U.S. competitiveness through the clean energy sector, the Department of Energy launched a state-of-the-art carbon fiber technology facility earlier this year at the Oak Ridge National Laboratory in Tennessee. The facility, supported by a $35 million DOE grant, will serve as a testbed for the development of cheaper, better-performing carbon fiber materials.
"We've really lost the technology. Part of our vision here is we're going to take it back," said Lee McGetrick, director of the Oak Ridge carbon fiber technology facility.
More than 90 percent of carbon fibers use the petroleum-based precursor polyacrylonitrile, or PAN, as their raw material. But converting PAN into carbon fibers is a slow, energy-consuming process requiring high temperatures and strict environmental controls. According to McGetrick, sourcing and producing PAN makes up about half the cost of the final carbon fiber product.
To bring down costs, Oak Ridge is looking to scale up production of two cheaper carbon fiber precursors: polyolefins and lignins. Polyolefins are plastic materials that could one day come from recycled products like water bottles or baby diapers. Lignins are bio-based materials and natural byproducts of pulp and paper mills as well as the biofuels industry.
However, harnessing these fiber sources is challenging. "In most studies, they have reported lignin is a very tough material to make into fine fibers," said Mahendra Thunga, a postdoctoral researcher at Iowa State University who researches carbon fiber. "The finer the carbon fiber, the more strength you have. Getting a fine fiber is very critical with lignin."
Nonetheless, proving the viability of carbon fibers from various waste streams would bring down overall costs, while bolstering the U.S. carbon fiber market and industries supplying it.