Molder H.R. Smith Group is enjoying a boom because of the growing aerospace market, seeing its sales double in a little more than three years as it finds a niche converting some high-performance applications to injection technology.
The Leominster, England-based company, which also has a small molding and manufacturing plant in Rockford, Tenn., has seen sales climb to about US$25 million in the past 3½ years, as interest in thermoplastic molding of some sensitive aircraft technology has taken off.
The 180-employee firm has added two injection presses, giving it a total of five in England and the United States, and has added computer numerically controlled machining equipment and more electronics assembly capability, said marketing manager Richard Smith.
It claims to be one of the world's four largest makers of high-performance antennas, along with locator beacons and other parts, and has found a niche taking some high-performance applications and applying injection technology.
For example, the Rockford plant uses polyetherimide to mold an electrostatic discharge rod for planes. The rod collects electrostatic buildup inside an aircraft and releases it, like a reverse lightning rod.
The traditional manufacturing process has been to make an aluminum base and then attach a fiberglass rod, said Chris Startin, a senior sales engineer with the firm, during an interview at the Asian Aerospace International Expo and Congress, held Sept. 3-6 in Hong Kong.
The key is in the coating the company applies, and in making sure it manufactures the tip properly, Startin said.
Like many of its applications, the company believes using injection molding can hold costs down.
But it also requires a finely developed knowledge of how to process finicky materials like PEI, polyphenylene sulfide and polyetheretherketone in an environment where components need to be able to operate in temperatures up to 392° F, Smith said.
``If you don't process it right, you end up with an inferior product,'' he said. ``We know how to process the material.''
The company was founded in 1966 by Henry Roy Smith, and it first got into plastic molding in the late 1970s, working on Britain's Harrier jump jet, the fighter plane that takes off and lands vertically.
The aircraft designers wanted to put an antenna on its underside, but the 392° F temperatures from the jet exhaust reflecting off the runways kept melting the fiberglass antennas, Smith said. So the company was able to figure out a way to mold them from glass-filled PPS.
As with many small aerospace subcontracting firms, the company works in a narrow niche.
Aircraft manufacturers like Boeing Co. are often quite averse to change, given the safety risks involved in new parts, so firms like H.R. Smith wind up focusing their innovation in some very specific windows.
The company has developed a technique of injection molding antennas for regional airlines, for example, which it said lets it form the radiating element as part of the process and encapsulating the base plate and connectors.
That eliminates some things that contribute to part failure, like unsupported radiating elements or the need to apply laminate to antennas, the company said.
Aerospace equipment has political challenges, too. Any potential military or dual-use technology that the company wants to export to China, for example, requires approval from the British government.
China is currently less than 5 percent of its sales, but it is growing, said Smith.
``We are only scratching the surface,'' he said.