The key to Select Charge® technology is its ability to provide different load lines, each optimized for a specific application. A load line represents the relationship between the gun voltage and current. As seen in the illustration, as the gun is moved closer toward the grounded part, the voltage decreases while the current increases.
The flatter the load line, the higher the gun voltage at a given current. Flat load lines deliver the high voltage needed for applications such as coating flat panels. Steep load lines deliver lower voltage relative to current, which enhances penetration into Faraday cage areas.
Conventional powder spray guns are designed with only one fixed load line. Operators can adjust voltage and limit current, but the gun will maintain the same voltage/current relationship. This is why guns that provide excellent performance on flat panels can be less effective coating recesses.
Nordson Select Charge technology provides four operator-selectable load lines, each optimized for a specific coating requirement. This allows powder coaters to achieve superior performance across a wide variety of parts for consistently high transfer efficiency and finish quality.