TPI Corp. (Johnson City, TN) manufactures a range of HVAC products, including portable electric heaters, industrial fans, duct heaters and infrared heaters. The company also manufactures light fixtures, thermostats and controls, and Fostoria-brand process heating equipment.

At its Gray, TN, facility, the company manufactures a number of products and components, including hydronic baseboard heating units. As part of the production process, TPI needed a means of sealing silicon into each unit's copper tubing. To perform the operation, the company implemented a Tube Termination unit from Sonobond Ultrasonics (West Chester, PA). Each tube terminator is comprised of a portable, handheld ultrasonic metal welder that can crimp and seal copper or aluminum tubing in a single step, without brazing or the use of consumables. As a result of incorporating the Tube Terminator into its production process, TPI is now able to produce the required leak-free assemblies more efficiently.

According to TPI test engineer Tim Maden, the company has found the system to be easy to operate, requiring only minimal training. The system also produces more units per hour than the crimping and sealing methods the company had used in the past, all the while creating fewer defects. In fact, Maden says he knows of no reports of leakage in TPI baseboards manufactured with this Sonobond technology.

TPI also uses Sonobond's Weldmaster system for spot welding some of the metal pieces that go into its snap disc switches, which are also manufactured at the Gray facility. Both the Weldmaster and the Tube Terminator employ a proprietary "wedge-reed" coupling system, which produces low-amplitude vibrations that ensure precise welds.

"Based on our experience, I would definitely recommend Sonobond to others," Maden says.

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