Issue link: http://www.e-digitaleditions.com/i/901126
28 POWDER COATING, November 2017 ent manufacturers is becoming harder to clean. Reasons range from offshore production of the metal to low quality and high demand domestically. Is there any truth to these claims, or are pre- treatment companies looking for a red herring? J.M., Sheboygan, Wis. SOLUTION Thanks for the question. It's really timely as I've seen a lot of questionable cleaning situations on the last few audits and road trips I've had. I agree wholeheartedly with the answer you've been given. Steel is more of an issue than aluminum. Just this week, I received a call from a worried powder supplier that one of his major accounts was going to switch to a chrome passi- vated cold rolled steel from the Far East. This of course is something you just can't do as conventional chemical solutions used in pretreatment can't re- move the chrome passivation. If you can't re-wet the surface, you won't achieve cleaning. In the cases I've wit- nessed, it leads to major failures. For example, I saw a case in the south- east in which the drawing compounds a p p l i e d i n h o u s e o n t h e p r e s s e s wouldn't wet out uniformly. This was caused from a change in mill oil, and it lead to major problems with the parts. In another situation recently, the cleaner wasn't removing all oils in all cases, whereas before the company changed substrates, it had never been a cleaning issue. We inspected the prob- lem and found that although the alka- line cleaner wasn't cleaning one partic- ular part, that part became 100 percent water-break-free after phosphate. In this case, we believed that the mill soil was more acid sensitive than alkaline sensitive, a true break from the norm. What does all this mean? It means there is a shortage in quality materials. Cou- ple that with manufacturers buying the least expensive metals possible from new sources, and you're bound to see different outcomes from different metal suppliers. Plants that had several industrial engineers and maintenance staff in the past are gone today. The new approach to manufacturing and finishing is lean, but just too lean in too many areas that require process control. In process control, you must control both the process and the incoming variables. Material management in- cludes the metals you're purchasing and processing. What can the powder coater do today? Start by re-auditing your metals, soils, and pretreatment. Get them back under control or im- prove your process to meet the wider window and cleaning difficulty. This is no red herring. It's for real! PC Editor's note For further reading, see articles under the Surface preparation head- ing in the "Index to Articles and Authors 1990-2016" Reference and Buyer's Resource Issue, Powder Coating, vol. 27, no. 6 (December 2016), or search the Article Index at www.pcoating.com. All articles listed in the archive are available for free download to registered users. Industrial Ovens Built to Last! ur ovens are competitively priced and structurally sound. We offer standard designs and custom sizes adapting to your special process needs. Typical processes that our ovens are used for include curing, drying, annealing, stress relieving, baking, aging, burn-off and pre-heat. Standard features • Digital read outs • Diagnostics • Hi-limit protection • Nema 12 control panel • Aluminized interior • Painted exterior Options: • Custom sizes • Custom controls • Gas or electric heat • Afterburners • Conventional • Hi-velocity for shorter cycles & save floor space O Call us today @ 517-784-9660 or email sales@jacksonoven.com Jackson Oven Supply Inc. 3507 Wayland Drive Jackson, MI www.jacksonoven.com Made in the USA Standard features Options Pass thru ovens