Powdercoating Capability Employing a Robotic Arm

[jfbock]

Hello,

I have a general question about powdercoating.

We recently started up a new pc line employing a robotic arm which repeats timing and movement of the spray gun. Despite that, we struggle with a consistent thickness.

I am troubled by our initial capability. Without revealing that, does anyone have an idea what a good cpk/ppk should be in applying powder? I have found nothing on a search engine that approaches this subject. Our customer has told us they wouldn't expect a 1.33 but that doesn't tell me much.

Maybe someone has a line they track where they've achieved an industry accepted standard. Would like to hear about that. At least, what should realistic expectations be?

 

[Miner]

Re: Powdercoating Capability

It has been quite a few years since I have been involved in powder coating, so I cannot help in your specific question. I can provide some general guidance in reducing process variation consistent with my experiences.

Good capability starts with the measurement system. Perform an MSA on your thickness gaging. PC thickness is affected by part geometry, so mark locations where you want the thickness measured. Don't skimp by using cheap thickness gages.

After you verify the gage is good, assess the thickness variation. Some variation is unavoidable (i.e., edge effects, threads, etc.). Determine whether the major source of variation is within-part, part-to-part, location on rack (if applicable), etc. Knowing the major source of variation will guide you toward an effective improvement strategy.