New Computer-Controlled Panel Painter Eases Complex Job

The Troy automotive laboratory of Akzo Nobel Coatings produces a lot of test panels. The introduction of one new dazzling color means hundreds and hundreds of panels that need to be produced for all sorts of short- and longer-term testing. Many of these panels end up on the fence in Florida or on racks in Xenon weathering chambers, gravelometers or other test machines.

“During the new color introduction periods,” says Tom Prescott, Group Leader for Exterior Coatings at Akzo, “we are cranking out test panels continuously in our laboratory.” Not only is the volume of panels high, but the quality demands are equally daunting. “We produce a lot of panels that use a three-step primer, basecoat, clearcoat system, each coating of which needs to be applied precisely with proper film-build control. That’s three times the headaches of a simple monocoat process,” he adds.

The test panels serve several important cosmetic and functional purposes. They are the means of testing new coatings against the rigors of weather, UV exposure and other elements that might cause failure, months or even years later. So the coating process must mimic the application of paint to real world product in terms of film build, cure and adhesion. But the panels are also used as color standards, which require precise control of application variables such as coating thickness, atomization, electrostatics and other parameters that could cause color and gloss variation from panel to panel.

Given these demands, Akzo Nobel recently installed a new Artomation PanelPro Plus machine to help with this demanding task. While they had experience with a large number of other panel-painting machines they felt that the rigorous demands of the market were requiring a new and better approach.

Not only does the Artomation machine make life easier by affording Akzo a much larger spray window than other machines, but it provides the ability to switch “easily, no, - darn near effortlessly,” between spray guns, or a rotary atomizer, according to Prescott. That’s because the PanelPro Plus design incorporates a tool “garage” with several different paint guns, each of which can be picked up and sprayed in seconds.

“With other methods of making panels,” notes Prescott, “we have to spray a basecoat and then clean out a gun to spray topcoat. The Artomation machine does all this automatically; greatly reducing the time and effort required by us.”

The much larger spray zone has a couple of benefits for the lab. First, it allows more panels to be sprayed at a time, which is a benefit to productivity. “But the larger spray zone also allows us to make a better test panel with less edge effect,” observes Prescott. “On a smaller machine where we cannot move the gun past the panel as far, we see less control over ‘windowing’ and other effects at the edge of the panel.”

Consistent film build is essential for the company’s test panels since too much or too little paint on the surface can translate into differences in appearance and performance. “We have seen that it is easier to correlate color for our customer when we can control the film build precisely,” says Prescott.

Precise film build is not just a two-dimensional issue for the lab, however. The PanelPro Plus features three servo-driven axes of motion, each of which is controlled through the PanelPro windows-driven computer interface. The interface allows lab staff to quickly create and download complex paths to the PanelPro machine through a simple-to-use graphic interface.

The real key to precise film build comes from the PanelPro’s ability to control not just motion but painting variables as it moves as well. At any point in the machine’s path, adjustments can be made to virtually any of the paint gun’s parameters (fluid pressure, atomizing air, shaping air, bell speed, electrostatics, etc.).

Akzo engineering staff integrated a plural-component mixing system with the Artomation PanelPro machine to give them the on-demand capability of spraying a number of their standard primers and topcoats along with specially formulated basecoats. “The combination of the mixing system and the Artomation machine give us much more flexibility and productivity,” says Stewart Kowalski, an Akzo technician who worked on the project. “We can produce far more good test panels with this system than we ever could have imagined with older technology.”

Kowalski also engineered a small, but separate room for the PanelPro installation to reduce the likelihood of dirt contamination on panels that need to have a highly cosmetic finish. “This ability to dial in the machine to produce nearly perfect panels is really unique and gives us a lot of peace of mind,” explains Kowalski, “and fortunately the simplicity of the machine’s controls allow us to actually take advantage of this control over panel painting without a lot of time or hassles.”

Artomation President John McDonough explained that the PanelPro machines are really a new generation of panel machine that have evolved during this era of graphic computer interfaces. We are used to great, simple, graphic control over all kinds of equipment in our world – but paint systems have lagged behind,” explains McDonough. “We decided to bring the same degree of sophistication and control to the panel painter that you have on an iPod,” says McDonough, “because cranking a few knobs and making mechanical adjustments just isn’t good enough anymore. PaintPro allows you to really control the process – not just precision movement of every axis, but all the paint variables. It can mean the difference between a poor panel and perfect one,” says McDonough.

For more information, visit www.artomation.com, e-mail sales@ artomation.com or contact at 877/805.1126.