Issue link: http://www.e-digitaleditions.com/i/765972
24 POWDER COATING, December 2016 I f someone told you that you could replace your existing organic finish- ing system with one that was com- pletely environmentally compliant and run it at lower operational costs, would you believe him? You might respond, "I'm not interested in trying new technologies that don't have a proven track record." What if this same person told you that this tech- nology has proved itself in thousands of installations throughout North America since the mid-1960's (Figure 1). Would that allay your fears? You might ask, "What is the performance of this new coating?" The advocate would reply, "In most cases, this type of coating has superior performance and appearance qualities when com- pared with all other organic finishes." By now, you would be wondering, "What new type of miracle coating is this person talking about?" And your friend would answer wryly, "Powder coating." You would then say, "I looked at that technology years ago and de ter - mined it to be too expensive to convert, too difficult to apply, too time-consum- ing to change colors, and too thick for my product." The advocate would sug- gest that you should reevaluate this technology in light of recent im - provements and cost reductions. Although this article doesn't cover all the technical issues of the powder coat- ing process, it does give you a general description of the materials and equip- ment that are unique to this process. It also outlines the advantages and dispels the myths that have been asso- ciated with this finishing technology. What are the basics of the powder coating process? All powder coating systems must have clean, dry parts before the powder is applied (Figure 2). Normally, the parts are cleaned and pretreated with aque- ous-based chemicals and then dried in an oven, although mechanical clean- ing (that is, media blasting) is accept- able as well. Of course, all parts that have been powder-coated must be cured (Figure 3) by using either heat alone or a combination of heat and ultraviolet (UV) cure systems. Powder coating materials. Powder coating is an organic finish that's divided into two basic categories: ther- moplastic powders and thermoset powders. Thermoplastic powders. These coating materials are applied as dry particu- late, melted, and flowed into a smooth coating when exposed to heat (approx- Powder coatings: Not just another pretty finish Nick Liberto, P.E. Powder Coating Consultants Figure 1 Applying powder coatings onto parts in an automatic spray booth Figure 2 Cleaning parts in a spray washer Photo courtesy Diamond Vogel/Peridium Powder. Photo courtesy Carpenter Chemicals.