Fayette firm is the world leader in explosion welding
A horn bellow followed by three shorter signals warns of the coming blast. The cry of "fire in the hole" rings out, followed by a muffled boom.
The ground vibrates, and a gust of wind and dust blows out of a hole carved in a hillside of a former limestone mine.
The symphony is over in a millisecond, as seven metal plates are merged by about 12,000 pounds of explosives, the result of a metal-fusion process conducted daily by DMC Clad Metal in Mt. Braddock, Fayette County, a division of Dynamic Materials Corp. of Boulder, Colo.
The company that has been using and expanding the explosion bonding technology since buying the business from E.I. DuPont de Nemours and Co. in 1996.
It has spent about $12 million during the past 18 months to add a 42,000 square-foot building to its production plant in Mt. Braddock. It employs 90, including about 30 hired in the past year.
"We are the world leader in explosion welding. The investment here means we believe there are opportunities for the future. Our end markets, energy and petrochemicals, are strong," said Yvon Pierre Cariou, president and CEO of Dynamic Materials Corp.
Explosion-weld cladding uses an explosive charge to bond plates of different metals that don't easily bond using traditional welding techniques, such as titanium and steel, aluminum and steel, and aluminum and copper. It also can be used to weld compatible metals, such as stainless steels and nickel alloys to steel.
Dynamic Materials is one of the few companies in the world that provides explosion-welded metal plates, corrosion-resistant products that are used in the petrochemical, refining, aluminum smelting and shipbuilding industries.
At the Mt. Braddock plant, the company uses ANFO explosives, which is ammonium nitrate and fuel oil. "We mix tons of it daily, all on site," said Gary S. Burke, vice president of operations.
Burke said the company can weld materials that are 16-feet wide, 45-feet long, 16-inches thick and weighing as much as 100,000 pounds. After the material is prepared for welding, it's loaded on large trucks and taken to the limestone mine in Dunbar, Fayette County, about six miles away from the main plant.
Burke said the company "shoots" only once daily, usually about 2 or 2:30 p.m, welding anywhere from three to 20 plates at one time. He said noise is negligible, since the explosion occurs about one-half mile underground.
The explosions are conducted inside the former limestone mine. The site was chosen because its home to the Loyalhanna seam, a 70-foot thick stratum of limestone valued for its hardness, and resistance to cracking, said Rick Vukovich, mine area manager.
"The limestone tunnel is a perfect tool. The rock is very hard, that's why it doesn't crumble," said Vukovich, 48, of Jumonville, Fayette County. The entrance to the mine is 50 to 60 feet tall, and 30 to 60 feet wide.
Dynamic Materials employs 230 workers companywide. It also operates plants at Nobleclad in France and Nitro Metall in Sweden. Both were competitors until 2001, when Dynamic Materials acquired them from Nobel Explosifs of France for $5.4 million.
"We understand the market, and we're not opposed to organic (internal) or external growth, should the opportunity arise. We still have a few, good competitors," Cariou said. He named Asahi Chemicals as a competitor. The Tokyo-based company also makes explosion-bonded metals.
Dynamic Materials also operates Amk Welding, a specialized welding unit in South Windsor, Conn.
Last year, Dynamic Materials reported net income of $20.7 million, or $1.70 a share, more than doubling the $10.3 million, or 86 cents a share, it reported a year earlier. Revenue in 2006 totaled $113.4 million, up from $79.2 million a year earlier.
The recent expansion, which includes several new pieces of equipment, will allow the company to boost material production capacity from about 194,000 square feet to 388,000 square feet annually. The company also will use a new roller/leveler, which is used to flatten the welded product after the explosion process, said Don Seder, 40, of Mt. Pleasant, Westmoreland County, and manager of the pre-bonding area at the plant.