Cover Story
August 30,  2004
Volume 82, Number 35
pp. 40-41


NOTHING BUT BLUE SKIES
Composite makers brace for extraordinary new use of their products in commercial aerospace
8235cover2_plane
BIG OL' JET AIRLINER An artist's computer rendering of a Boeing 7E7, scheduled for service in 2008 and bearing the marking of Japan's All Nippon Airways.
BOEING PHOTO

ALEXANDER H. TULLO, C&EN NORTHEAST NEWS BUREAU
 
The mood around the aerospace composites industry these days can best be described as ebullient. Customers in the commercial aircraft sector are coming out of a long slump. On top of this, a revolution leading to new and unprecedented use of composites in commercial aircraft is well under way, signaling strong composites growth for years to come.

Suppliers of composite materials, such as high-end carbon fiber and epoxy resins, can take some of the credit for the boom. They developed many of the technologies that are enabling new applications in aerospace. What remains ahead for them is to add enough manufacturing capacity to accommodate the growth.

Carbon fiber-based composites consist of a carbon fiber reinforcement typically held together by a thermoset resin matrix. The carbon fibers are usually polyacrylonitrile (PAN) fibers treated under intense heat. Aerospace applications use high-end, "small-tow" grades of fiber with high-performance epoxy and phenolic resins. Industrial applications such as offshore oil platforms and windmill blades usually use lower end, "large-tow" fiber grades with epoxy and vinyl ester resins.

According to Ben M. Rasmussen, head of North Plainfield, N.J.-based BMR Consultants, the global market for PAN-based carbon fibers is 20,000 metric tons per year. Aerospace accounts for 28% of the market, while sporting goods and industrial applications make up 20% and 52%, respectively.

In recent years, the aerospace composites business has suffered from plummeting output at the two main commercial aircraft suppliers, Boeing and Airbus. Between the two companies, aircraft deliveries decreased from 914 units in 1999 to 586 in 2003.

Rasmussen says the slump drove global growth in demand for PAN-based carbon fibers down to 2 to 4% annually, with an actual decline hitting the U.S. Previously, carbon fiber grew at an 8 to 9% average annual rate.

Jon Stowell, a vice president of sales and marketing at Hexcel, says the poor economy also affected demand for composites in industrial applications. "Demand had fallen enough that we temporarily closed down some fiber lines," he says.

However, this year, aircraft makers say production is starting to turn around. Boeing says it will make 285 aircraft in 2004 and 315 in 2005. Airbus predicts building more than 305 aircraft this year, followed by 10% growth next year.

Moreover, the military aircraft sector has been strong because of the Iraq War, the war on terrorism, and an emphasis on a more nimble military. New programs such as the Joint Strike Fighter, the F/A-22, unmanned aerial vehicles, a host of ordnance, and even new ships put an emphasis on advanced composites.

"There is a marked increase in demand for carbon fiber, particularly on the aerospace side of the business, due to commercial aircraft showing signs of life and the military sector humming along," Rasmussen says.

Steven C. Speak, president of Cytec Industries' engineered materials division, which relies on aerospace for roughly 90% of its business, welcomes the improvement at Boeing and Airbus. "They have announced an increase in their production rate, which is a nice change for our industry given the last few years where they have mostly been shrinking production," he says.

But Speak, along with other observers, is even more excited by new commercial aircraft, where penetration of composites will dwarf anything seen before.

The Boeing 7E7, a new family of jetliners scheduled to go into service in 2008 with a seating capacity of 220 to 290, will be 50% composite. In contrast, the Boeing 777, launched in the mid-1990s, is only about 9% composite.

SO FAR, Boeing has received proposals for the purchase of more than 200 7E7s. To accommodate the massive amount of carbon fiber it will need, Boeing has signed an 18-year supply agreement with Toray Industries, a maker of carbon fiber and pre-preg--carbon fiber tape that is impregnated with resins for parts fabrication.

At the time it inked the contract in May, Toray said it had already been planning expansions in advanced composites. It is doubling carbon fiber capacity at its Decatur, Ala., unit to 3,600 metric tons per year by 2006. It is also building an upstream PAN plant and a downstream pre-preg plant. It is tripling carbon fiber output at its Abidos, France, facility to 2,600 metric tons.

Toray has had a long relationship with Boeing. The Japanese firm already supplies pre-preg for the 777's floor beams and, more notably, its tail assembly--the first use of composites by Boeing in the primary, critical-to-flight structure of a commercial aircraft. Toray has also been a carbon fiber supplier for secondary components of the Boeing 757 and 767.

Boeing made the materials selection after a long "horse race" between carbon fibers and advanced aluminum. However, Al Miller, technology integration manager for the 7E7 program at Boeing, makes it sound as if it wasn't much of a contest at all. "It's not just one benefit," he says of carbon fiber. "There are many."

Miller says composites' combination of high strength and light weight allows for greater fuel efficiency and less emissions. A single composite part can replace a complex structure consisting of many parts, reducing manufacturing costs. Assembly is 30 to 40% faster with composites. And almost all of the composite materials purchased are used in the final aircraft; with aluminum, 90 to 95% of the purchased material has to be scrapped.

Moreover, Miller says, composites are more durable. They are eminently more corrosion resistant. And they don't suffer from metal fatigue--the wear in flight that typically retires aircraft. "Composites have a longer life than other materials, which lowers the amortization cost of the aircraft," he adds.

Observers also note that Boeing is embracing composites as a weapon in its rivalry with Airbus. Boeing has gone from holding more than two-thirds of the market in 1999 to less than half last year. The 7E7, observers say, puts Boeing back on the offensive. "Boeing knows [its] future is strongly tied to continued supply of carbon fiber, both on the military and commercial side," Rasmussen says.

Airbus is also beefing up the use of composites in new aircraft. The A380, a 555-passenger behemoth scheduled to go into service in 2006, will be 25% composite, a far cry from the A300 of the 1970s, which was only 5% composite. Airbus has already signed up 129 orders for the A380.

Experience is making aircraft builders more comfortable with composites. For example, Miller says Boeing selected Toray's materials for the 7E7 because of their successful use in the 777. "It is a robust, mature material system that has demonstrated its capabilities in service," he says. "With nearly 10 years of in-service experience, over 400 airplanes flying, and exhaustive testing, we're very confident we understand this material."

Miller is even unfazed by the crash in New York City of American Airlines Flight 587 in November 2001. In that crash of an Airbus A300, composite materials in the tail section have been under investigation, though, so far, the National Transportation Safety Board hasn't reached a conclusion. Miller says Boeing tests materials to meet or surpass safety requirements and points out, "To date, no composite materials have ever been determined by an investigating agency to have caused an airplane crash."

Ashraf Chaudhari, regional head for structural composites for the Americas at Huntsman Corp., which last year purchased epoxy resins maker Vantico, says firms like Boeing and others have also proven composites on the military aircraft they have built over the years. "The military has always been more open to composites," he says. "They are always looking for high performance."

The benefits of advanced composites have been well known for a long time, but recent technology developments have lowered composites' cost enough that significant use in commercial aircraft has become more economical.

Miller says this is why composite materials were scaled up in the 7E7. The cost reduction, he says, has been driven by labor-saving process advances. "The material system has been ready for a long time, but it has not been cost effective for large structural applications until recently due to advances in manufacturing technologies and design for use of those manufacturing methods," he says.

Cytec's Speak agrees. "There's been some maturing in both materials and process technologies so that it costs less to build composite parts," he says. He explains that materials have been optimized for use with robotic equipment or tailored for processes that save labor and obviate the need for expensive autoclaves.

Composite materials suppliers have applied chemistry expertise to enable these processes to be used in aerospace. For example, in processes where the parts fabricator injects resin into the carbon fiber, a low-viscosity resin is needed. However, these resins typically don't have the structural properties needed in aerospace.

Cytec has developed a technology in which a thermoplastic reinforcement is woven directly into the carbon fiber. The thermoplastic later melts into the thermoset resin while the part sets. The technology is being used in spoilers of the Airbus A330 and A340. Cytec will not disclose what the polymer is, but Speak points out that plastics such as polysulfones and polyetherimides are generally used in composite reinforcement.

SIMILARLY, Huntsman has been working on benzoxazine chemistry to make high-modulus and high-strength epoxies for resin transfer molding applications.

Hexcel recently debuted resins and fabrics tailored for resin film infusion techniques. The new products were included in an engine part demonstrated by Goodrich Aerostructures at the Farnborough airshow earlier this year. Like Cytec, Hexcel is coming out with materials for robotic processes like automated tape layup and automated fiber placement.

Thanks to all these developments, materials suppliers are expecting huge demand gains. One executive predicts that his business will see 10 to 15% annual growth in advanced composites over the next six years or even longer. "The next 10 years are looking pretty good," he says.

However, some observers wonder, as has happened in the past, whether constrained capacity will put composite materials in short supply, driving up prices and slowing their use. Rasmussen predicts that demand for PAN-based carbon fiber will be 30,000 metric tons in 2007, outstripping today's capacity by some 10,000 metric tons.

However, like Toray, composite materials suppliers are preparing for the business. Cytec is expanding composite materials manufacturing in Germany to support its supply of Airbus in Europe. It is also expanding, through improvement projects, the carbon fiber operations it purchased from BP in 2001. Similarly, Hexcel says it is considering expansions in carbon fiber.

Huntsman is expanding a plant in Switzerland to make resins for advanced composites. The expansion will establish a second source of supply to the company's plant in McIntosh, Ala.

Huntsman's Chaudhari has little doubt that composites producers will be ready for the prosperity that they have been working so hard to make possible. "People have been hurting for the last four to five years. This is an opportunity to realize investments," he says.

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