Sintering Technologies, Inc.
Sintering Technologies, Inc. (STI), Greensburg, Indiana needed to replace aging delubing units on two sintering furnaces in 2004, reports Gregory T. Owens, executive vice president. “The units had deteriorated and were difficult to operate,” he says. ‘Our operators had to adjust the air-to-natural gas ratio fairly often, and were constantly adjusting to accommodate different size PM parts. The units were too complicated and not operator-friendly.”
Founded in 1989 by Hitachi Powdered Metals Co. Ltd. of Japan, STI is an important powder metallurgy (PM) parts supplier to major automotive OEMs. The company is well-known for manufacturing high-quality and high-precision PM parts – valve guides and valve seats, pulleys and sprockets, camshaft plates, and timing gears.
In a fortuitous move, Harb Nayar, president of TAT Technologies, Inc., called on STI in 2004 to introduce his new patented technology. While meeting with STI engineers he learned about their problems with delubing PM parts. Nayar was familiar with the company’s sintering operation because he helped install the nitrogen based atmosphere system in 1989 when he worked for BOC Gases. “After listening to the STI engineers and checking one of the problem units, I recommended a solution for the delubing problems that would also increase productivity by more than 25 percent,” he recalls. Sooty or dirty PM parts, frequent cleaning of heating elements and surface decarburization and/or “frost” were some of the problems STI experienced.
STI agreed with Nayar’s suggestions and installed the first LBT-III unit in the preheat section of a 36-inch belt sintering furnace in 2004. A second unit was installed in 2006 on a 24-inch belt furnace. “The units were up and running in three days,” says Elizabeth Gearhart, process engineer. “Once the settings are established, the LBT unit operates smoothly on its own,” she says. “Our furnace people love the system. It’s a no-brainer to operate.”
TAT’s system of automatic delubing utilizes the existing hydrogen gas and lubricant vapors coming out of the PM parts, which creates vibrant flames above the parts entering the furnace. This is accomplished at no additional cost, STI reports. The compressed air is heated prior to injecting it into the atmosphere through the LBT, which eliminates the need for natural gas. Only very inexpensive flow meters are needed. Sooting associated with the older unit, was reduced significantly. Costly cleaning steps were substantially reduced as well. The LBT unit allowed a heavier loading of trays containing the parts for sintering. In addition belt speed was increased by 20 percent. The combined result was a more than 40 percent increase in overall productivity. “The system is virtually maintenance-free,” Owens says.
STI is still very satisfied with the LBT system and TAT’s technical support. Greg Owens says, “Why didn’t someone come up with this idea before? It’s so simple and practical.”