How to Limit Rack and Twisting in a Coating Line

In April, we were featured in Products Finishing magazine in the "Rack" section. Scott Rempala gave his response to this pressing racking question from a coater:

"Our team believes that we typically have good rack density, but the racks sometimes twist a little in on our coating line, which creates coverage problems. Can you suggest how we might limit this problem?"

Below is a sneak peek of Scott's knowledgeable answer. To read the full article, click here.

"The issue you are describing is not uncommon. Rack tracking, as our engineering team likes to call it, is as important to coating quality and efficiency as rack density. For this discussion, I will use the term 'tracking,' as the same concepts apply whether you are using a rack, hook or other hanging method. Tracking is an essential element of part presentation, which is the method of presenting the part to the coating equipment, where it will receive the maximum uniform coverage on critical surfaces without pooling pretreatment solutions or accumulating debris. Additionally, proper tracking will improve pretreatment quality and reduce the possibility of 'hang-ups' or crashes in your system due to out-of-plane hangers contacting elements of the coating operation.

According to most equipment suppliers, your parts should be equal to or less than 5 degrees parallel to the guns, if coating with automatic guns or by robotic sprayers. This can be difficult to accomplish if your hangers are not consistently presenting the part due to instability of the hanger-to-line attachment. Swaying or twisting of the hanger through the coating booth can also present challenges to manual sprayers, as they will have to constantly adjust to inconsistent part patterns..."