Switching from a liquid to a powder coating operation has helped Sternberg Lighting increase quality and efficiency while reducing its impact on the environment.

"Lighting up America since 1923," Sternberg Lighting of Roselle, IL, manufactures lighting fixtures and ornamental poles. Along with creative, high quality illumination solutions, their product line also includes "site amenities" such as street signs, mail boxes, trash receptacles and clocks. All across America, neighborhoods, parks, cities and towns have dressed up their streets with beautiful lighting solutions and accessories manufactured by Sternberg. The company is 100% employee owned, and its employees take great pride and ownership in the craftsmanship of the products they manufacture. Doing business for more than 80 years, Sternberg is known as a leader in the lighting industry and is committed to continuous process improvement.

Several years ago, responding to environmental pressures and customer demand, Sternberg made the decision to include powder coating as a finishing option. Powder coated finishes are known to be highly durable and able to withstand harsh environments without chipping or fading, and many architectural firms are specifying powder coated finishes in their projects. Although some of Sternberg's small parts are still liquid coated, the majority of its products today are powder coated.

Fast Color Change

The color palette at Sternberg consists of 90% black; however, the company also customizes projects to meet any specification desired by its customers. This unlimited color palette potential creates a challenging color change environment. The challenge is met by thoughtful planning that helps speed up the color change process. Using a 10,000 cfm Diamond™ booth from ITW Gema, a long run of black parts is completed first, and the powder is reclaimed and reused. Once the black run is complete, the booth is thoroughly cleaned. Parts are then passed through the booth in a series from light to dark color runs until the company once again reaches a black run. All custom colors are sprayed to waste and are not reclaimed.

A complete color changeover from scrap to black takes about 45 minutes, while the average color change time on spray-to-waste is only 5 to 10 minutes. According to George Howe, Sternberg's Finishing Department supervisor, "My experience has been that, except for very small parts, color change time with the powder system is much quicker than with a liquid system. You also don't have to deal with disposing of all the solvents associated with a liquid system."

Sternberg's finishing line includes a manual powder coating booth with EasySystem™ touch-up units, as well as a fully automated booth containing OptiGun™ automatic powder guns and OptiTronic™ control units. Using a vertical light curtain in the system has allowed Sternberg to maximize efficiency and save money. When a part moves through the light curtain array, a signal is sent to the Genesis control package that triggers only the guns necessary to coat the part. Automatic triggering prevents guns from spraying vacant space and dramatically reduces Sternberg's powder consumption.

A High-Quality Finish

Converting from a mostly liquid to a mostly powder operation made good economic sense, and Sternberg has been pleased with the positive results. The finishing environment is extremely clean and safe, and Sternberg is able to produce products with a consistently high finish quality, while achieving more than 70% transfer efficiency. Rejects are rarely attributed to finishing problems. Automatic gun triggering and the ability to reclaim powder contribute to a healthier bottom line for Sternberg, making its finishing system efficient and cost-effective to operate.

Switching from liquid to powder is just one more way Sternberg Lighting is continuing to improve its processes to remain a leader in the lighting industry.