When Graco needed a vendor to build electric motors for a new electronic airless sprayer it was designing, it contacted Pacific Scientific (PacSci) in Rockford, IL. PacSci is a leading manufacturer of electric motors with a reputation for producing high quality products. Their motors are built and shipped to manufacturers who use them to drive the products they build, such as treadmills, vending machines and airless paint sprayers.

“PacSci has been manufacturing electric motors for a quarter century,” says Don Neumann, Product Marketing Manager. “We are successful because we are sensitive to our customer’s requirements - often, these are very specific requirements. Furthermore, our quality control is extremely high, and we go to great lengths to assure our customers are satisfied with our products and the services we provide.”

When they discover a situation that could cause production or quality problems, they’re quick to seek changes. For instance, they recently upgraded their finishing line which improved product quality and manufacturing efficiencies.

According to Steve Beach, sr. manufacturing technician, the protective coating they applied to the motor housing was a single component enamel paint, some of this material contained silicone. The paint was pumped from pressure pots to air spray guns. One line was set up to spray the paint electrostatically.

Unfortunately, the single component materials, especially the silicone enamel paint, were causing production and quality problems. This was unacceptable to PacSci. Rejects were high and the parts took too long to dry in the ovens after the topcoat was applied.

They discussed their options with their paint supplier and settled on a two component epoxy coating. At the same time, they realized that hand mixing the two part material would be labor intense, cause more waste, and did not guarantee ratio consistency. The logical choice was a proportioner. After considering mechanical and electronic proportioners they selected Graco’s ProMix™ electronic proportioner.

Graco’s ProMix proportioner proportions, mixes and transfers two component coatings. The system features an easy-to-use, icon-driven display panel that requires no special operator skills or training. Complete on-line diagnostics provide a fast, accurate indication of mixing and spraying conditions.

Furthermore, ProMix is air-driven, providing intrinsically safe operation. “This allowed us to install the proportioner right next to the spray booth so the painters have instant access to all the system’s functions,” says Beach.

The ProMix system delivers on-ratio material by maintaining pre-defined mix ratios to within +1%. The mix ratio of the paint PacSci is currently using is 1:1. “However, If we ever change materials and they have a different mix ratio we can easily change the mix ratio on the Promix by simply changing a few commands.”

Other features that are important to Beach and the painters are the off-ratio alarm and pot-life monitor. “If an off-ratio condition occurs — let’s say we’re running out of one of the components — an alarm is activated, and the system automatically shuts down, preventing the application of off-ratio material. An alarm will also alert the painters if the mixed paint has been setting in the lines too long.”

“We’ve reduced rejects significantly,” he says. “In fact, less than one percent of the products we paint are rejected because of poor finish quality.”

Beach explains that the motor housings are assembled from up to five different parts. Most of the time, these parts are not finished from the same batch of paint. Before the ProMix was installed, the color and texture of the different parts did not often match. This was very noticeable when they were assembled.

“This was unacceptable,” he says.

“The ProMix is accurately mixing the paint and we don’t have to worry about color match anymore. The color and texture are consistent from one batch to the next.”

Furthermore, the paint and the proportioner have allowed PacSci to increase line speed by 20-30 percent. Two reasons for this increase are because the new material dries faster at a lower temperature and because the painters spend less time performing color changes.

“We’re using less paint too. On one product we’ve reduced the amount of paint we use from 300 cc/minute to 120 cc/minute. We attribute the savings to the Graco PRO5500™ electrostatic spray gun which provides an excellent wrap.”

PacSci’s finishing system is simple, but efficient. Parts are loaded on a chainon-edge conveyor. They travel through two water wash booths. In the first booth, two automatic HVLP spray guns apply a single component waterborne primer. It’s a fast drying primer and can be painted over as soon as the parts enter the second spray booth where the topcoat is applied. Three different applications can be performed in the topcoat booth. The Graco automatic electrostatic PRO 5500 is used to apply their most standard color -blue. A Husky™ 307 diaphragm pump transfers the catalyst to the proportioner while a Husky 715 diaphragm pump transfers the base color. Graco agitators mounted on the drum covers keep the materials suspended in the drums.

There is also an automatic Graco AA Plus™ air assisted airless spray gun for other coatings. The painters can use air spray guns with quart pressure cups to apply shorter color runs or as touchup.

After the parts leave the spray booths, they travel through an oven for 30 minutes at 180° F. Then the parts are removed from the conveyor and are transported to the assembly area.

The lower heat also allows the entire motor to pass through the oven in the event a finishing flaw is discovered after the motors are assembled.

“We’re very happy with the new material and ProMix,” says Beach. “They have had a significant impact on our production and quality. Furthermore, they help us maintain the quality and service our customers demand from us.” •