Up to $1.4MM Annual Savings, SPI Award
Trane, the air-conditioning systems and services business of American Standard Companies, works to improve productivity on existing products by six percent every year. Because of quality issues with the cosmetic top cap for its top-of-the-line residential air conditioner, the top became an ideal candidate.
“We knew we couldn’t simply expect our supplier to take six percent out of the price of the product while still maintaining the quality,” says Bob Kiermaier, Trane strategic commodity manager. “To accomplish our goals, we needed a collaborative environment where we could work together to change processes.”
In addition to cutting costs, the Trane redesign team wanted to streamline manufacturing by consolidating the original multi-piece assembly into a single part. Formerly, the cover was built of five separate parts, requiring three molds to produce each part. The parts then had to be glued, often leading to loose louvers that contributed to a number of problems. “You can imagine the productivity gains that were possible just through mold reduction alone,” says Ken Kincaid, Mack technical engineering manager.
The eventual new top cap design involved design, processing and assembly changes. The part is injection molded at Mack’s Inman, S.C., plant. Injection molding produces fast molding cycles for a high volume part with cosmetic requirements. External gas
is also used, however, to produce the cavity texture and improve part ejection from the tool. External gas-assist molding also lowers the injection pressure required to fill the part, reducing press size requirements along with costs.
The material choice for the new design is a UV stabilized polycarbonate resin for strength, impact, long-term aging, cosmetics and the color stability required for an outdoor application.
The most impressive technical aspect of the project is reflected in the part’s geometry changes and how they work with the tool design. “Slide lines in the tool combine with style lines on the side of the part, eliminating any interruption in texture appearance,” explains Kincaid. “And because the louvers are now integral to the part, its structural aspects and strength properties are improved. Most of the core side ribs that were previously needed have been eliminated, as well as the associated sink and flow disruptions.”
“The absence of any read-through on the top surface results in a better overall appearance,” adds Trane Plastics Engineer Richard Jameson. “The Xli badge can only be installed in one location, and there is better screw-hole alignment for assembly and increased structural integrity.”
The bottom line? The redesign yielded a top cap that will cost up to $1.4 million less per year to produce, according to Kiermaier. It also won the Building & Construction category of the Society of the Plastics Industry’s annual plastics design competition.
“Collaborating on a project like this is an effective strategy to use with a major supplier,” says Kiermaier. “Working closely with the supplier and sharing the cost benefits is always going to work better than a unilateral dictate.”
The Xli top redesign team included staff members from Trane Residential Systems, Mack Molding, Advanced Innovative Design and Delta Mold.
Contact: Jack Katilius, Mack Business Unit Director
Ken Kincaid, Mack Technical Engineering Mgr.
Trane is a leading global provider of indoor comfort systems and comprehensive facility solutions. Its offerings include energy efficient heating, ventilating and air conditioning systems, service and part support, advanced building controls and financing solutions. For more information, visit www.trane.com.