Composites Take Off : While some aerospace sectors contract, the Southland’s makers of reinforced plastics try to keep up with demand.
When the Northrop B-2 Stealth bomber--variously described as looking like a bat, a whale or an alien spaceship--lifted off a Mojave Desert runway for the first time last July, world attention focused on the aircraft’s unconventional aerodynamic shape.
But the flight also signaled a major leap forward in the use of composite materials, the reinforced plastics that are finally coming out of research labs and into major production programs.
The aerospace industry has researched and tested composites for decades, but only in the past several years have manufacturers made large-scale shifts to lightweight composites from traditional aluminum for aircraft structure.
Although much of the aerospace industry faces a difficult contraction these days, the specialty companies that have staked out positions in composites are more concerned with managing explosive growth.
“We are growing at an average of 25% a year, said Stephen Gill, president of M. C. Gill, a family-owned company in El Monte that specializes in making composite floors, ducts and cargo liners. “I have been here for 25 years and things have never looked better. If I could get the people in place, I could double in size tomorrow.”
As in past aerospace industry evolutions, Southern California has emerged as the center of the composites industry, possessing a rich mix of major prime contractors, large specialty subcontractors and smaller vendors of everything from composite parts to capital equipment.
“I can’t think of another area of the country that has more going for it than Los Angeles,” Thomas Hynes, owner of Composites Horizons, a Covina-based producer of advanced composites for aerospace and health care.
A major impetus of recent growth has been the development and production of stealth technology aircraft, which are designed to evade detection by enemy radar. Composite materials play a central role in the ability of stealth aircraft to absorb and deflect radar waves.
The B-2 bomber is possibly the most advanced aircraft in its use of composite materials, although much is still secret. Northrop officials declined to discuss the types of materials or the amount of materials used in the B-2, but industry sources estimate that composites make up about 80% of the B-2 structure.
Composites are made of two essential ingredients: high-strength fibers that have been woven into tape or broadcloth and polymers that bind the fabric into a rigid and lightweight matrix. Carbon, graphite and glass are the most typical fibers used. Epoxy, polyester and phenolics are the most typical polymers used.
In producing parts, the tape or broadcloth, which is impregnated with the polymer, is laid down on to a mold that represents the shape and contour of the part. Then, the entire piece is cured in an autoclave at a temperature of about 350 degrees and a pressure of 100 pounds per square inch.
The resulting part is typically 30% lighter than a comparable aluminum part and has four times the fatigue life--critical parameters in aircraft design. Such parts can also be substantially stronger than aluminum because it is possible to orient the fibers so that the part is strongest in the direction that bears the greatest load.
Art Rosene, Northrop project engineer for advanced programs, said the technology involved in producing the composite parts for the B-2 is just as advanced as the aircraft itself.
In the early 1980s, Northrop built its Integrated Composites Center in Pico Rivera at an abandoned Ford Motor car factory, part of a $1.2-billion investment in new technology. Today, it is believed to be one of the biggest composites fabrication facilities in the industry, Rosene said.
Rosene said Northrop has developed a computerized system that directly transfers three-dimensional designs for aircraft parts to machine tools in the factory. The company has also pioneered a new software system to automate the production of composite parts, increasing both efficiency and accuracy.
Automating the fabrication of composite parts has been critical to increasing their usage. Northrop has developed what it calls a geodetic software system that permits complex contours to be built with automated tape-laying machines. Other manufacturers, including Lockheed, assert that they have the same capability.
“It is like trying to wrap masking tape around an orange,” Rosene said. “No matter how hard you try, there will be gaps where the tape doesn’t touch the orange.”
So far, aerospace companies have turned to composites because they are best for the mission of the aircraft or spacecraft, such as in the stealth technology case.
The drawback with composites is
their cost, both for raw materials and labor. But automation is rapidly bringing down the manufacturing cost, and aerospace experts say the day is close at hand when composite parts can be built and assembled as cheaply as aluminum.
“In most cases, you can’t beat the cost of making individual parts out of aluminum, but when you start putting the airplane together, that’s where composites really shine,” said Arthur James, a Lockheed program manager at its Composites Development Center in Burbank. “Most of the parts that make up an airplane are pretty small, and it costs a lot of money to put them together. So, we want to eliminate a lot of these smaller parts with more complex composites.”
In another vote of confidence for the future of composites and for the Southern California aerospace industry, Lockheed is building a major composites fabrication facility in Palmdale.
James said composites will make up 40% to 50% of the advanced tactical fighter, the next-generation Air Force jet that is being developed in a competition between Lockheed and Northrop. By comparison, the F-15 fighter developed in the early 1970s had only 4% of its structural weight made up of composites.
In gross measures, the aerospace industry is rapidly increasing its use of composites. Including both military and commercial sectors, the industry used 41.1 million pounds of composites in 1989, up from 39.4 million in 1988 and 36.4 million in 1987, according to Stuart Lee, technical director of the Society of Materials and Process Engineers.
But in some specialized areas, particularly the use of high-strength carbon fibers, growth is even more rapid. Consumption of carbon fiber composites is projected to grow from 5.3 million pounds in 1988 to 11.3 million pounds in 1994.
The next big breakthrough in composites will be production of thermoplastic composites, a breed apart from the current generation of thermoset composites.
With thermosets, the parts take their final shape in the autoclave. But with thermoplastics, the heated laminates come out of the autoclave and are pressed into their final form, much like metal is stamped in a press. Thermoplastics could dramatically cut production costs and virtually eliminate current environmental problems with emissions of volatile solvents and other toxics.
In addition to the big aerospace firms and smaller subcontractors, Southern California has a huge supply industry, including six major firms that impregnate fabric with polymers. They are called pre-preggers.
Hitco, Hexcel, Sargent-Fletcher, Air-Tec, Richmond Technology, Ferrow, Ciba-Geigy, American Cyanamid, Fiberite and others also are players in the local industry. Total employment is unknown but is believed to be in the tens of thousands.
B. F. Goodrich makes composite aircraft brakes in Sante Fe Springs and is moving into building high-temperature parts for the new National Aerospace Plane, the craft that will take off like an airplane and soar into space like a rocket.
The industrial infrastructure also includes three manufacturers of plastic vacuum bags that are used in the autoclaves. One small vacuum bag maker, Bondline Products in Norwalk, has as many patents as it has employees--four. It is making a line of reusable bags to displace the costly throwaway bags. Cosby M. Newsom, president of the firm, said his technology can reduce by a hundredfold the time that it takes to bag a part.
Even though Southern California has the largest pool of skilled aerospace workers in the country, composites companies face a severe labor shortage.
“I have 30 companies looking for people,” said Terry Price, chairman of the department of manufacturing technology at Cerritos College, a major regional center for composites studies. “Companies are just screaming for people. There are jobs for lab technicians, salesmen, engineers, lay-up fabricators and quality control inspectors.”
Cerritos College is opening a 10,000-square-foot manufacturing technology center for composites and plastics, James said, funded in part by a consortium of local aerospace firms. Meanwhile, at the higher academic research level, UCLA has become a leading center for research into high-temperature composites, including ceramic, metal and carbon composites, according to Professor J. M. Yang of the school’s department of materials science and engineering.
THE GROWING USE OF COMPOSITES
Development of composites has reached the point where application is moving from military sectors into the commercial sectors of the aerospace industry. This raises expectations of revolutionary methods of airframe construction that will considerably exceed the potential of most present-day eqiupment.
F-117A STEALTH FIGHTER: The Lockheed F-117A Stealth fighter makes the first broad application of composites technology to a U.S military jet.
B-2 STEALTH BOMBER: The Northrop B-2 Stealth bomber is the first heavy aircraft built mostly of composites, used extensively in its skin and in its structure. The bomber has composite stringers, reinforcements that span its frames.
B-1 BOMBER: This present-day bomber has incorporated the use of composite materials in the follwing places: 1) fuselage, 2) wings, 3) tailcone, 4) engine inlets. Use of composite materials in the next generation of aircraft coming into production will be even more widespread.
SLATS: Used to chamber the wing for high lift at low speeds and high angle of attack.
WING TANKS: Fuel is housed in self-sealing tanks inside the entire wing.
TAILCONE: Houses a large part of the electronic countermeasures system.
VARIABLE GEOMETRY WING: The swing wing is moved into the swept position by hydraulic screw jacks. The fully swept position is used for supersonic flight.
