Dear Joe,
I would like to respond to your request for ideas regarding managing spent powder in your July 2007 column (see below). My company recycles latex paint and similar products into latex paint for resale. We also have a patented process that addresses poor quality latex paint and spent powder coat. Through that process in our Minnesota and California plants, we produce a cement additive and keep waste paint and spent powder coat out of the landfill. I would be happy to test samples of spent powder coat from any of your readers. Please pass along my contact information.

Best regards,
Mac Hardaway

Mac Hardaway, General Manager, Amazon Environmental, Inc., Riverside, CA, mac@amazon.mpowermail.com, www.AmazonPaint.com


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Dear Joe,
What gloss range is best to obtain the full benefits of TGIC superdurable series in powder coatings? Is it over or under 50 degrees? Also, is the integrity and true nature of superdurables compromised when ingredients such as waxes, fillers, matting agents and teflons are added to reduce the gloss?
--DSmooth

Hello DSmooth,
I have to make an assumption to provide an answer to your first question. By “full benefits,” I am assuming that you mean outdoor durability and, more specifically, resistance to gloss loss and chalking due to exposure to sunlight and moisture. As for the influence of gloss on performance, this should be a non-issue. In a perfect world, the best gloss range would be the one specified for a particular product by the powder coating manufacturer. However, not all powder formulators approach this situation equally. In some cases, the quality of the powder coating is diminished when the gloss of the powder is reduced.

One way to assess expected quality is to obtain a product data sheet (sometimes called a technical data sheet) from your powder supplier. This sheet will quote the expected performance of properties such as gloss, flexibility, corrosion resistance, outdoor durability and sometimes hardness and coverage. Outdoor durability is sometimes referred to as the number of hours a coating endures an accelerated exposure protocol, such as QUV. However, this is a comparative test and is not an exact predictor of the amount of exposure in a given environment.

With regard to your question on additives, some additives decrease ultraviolet (UV) resistance, some don’t, and a few improve it. Smart formulators know the difference. If they don’t, they check the performance before the product reaches you, the applicator.

I hope that this answers your question.


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Dear Joe,
We have a lot of spent powder that we have to dispose of in a landfill. Are you aware of any facilities that can take spent powder and reuse it as a raw material or have another use for it in lieu of disposing of it?
--Sandra Forsyth, EHS Specialist, McLaughlin Body Co.

Hi Sandra,
For years the powder coating industry has looked for a means to eliminate obsolete powder. For a while it was thought that perhaps the concrete industry could bleed some old powder into their mixes, but this wasn’t possible due to quality issues. The use of spent powder was also pursued as a fuel for industrial processes. However, I don’t think this application materialized. I’ve encountered companies that buy and resell unwanted powder. Surplus Coatings in Grandville, MI, is one example.

A couple of entrepreneurs in Akron, OH, have pioneered a novel process that uses obsolete paint, powder, plastics and even synthetic carpet as feedstock to a cracking process that produces a variety of petrochemicals. We featured this technology in the December 2006 issue of Finishing Today (True Recycling of Scrap Paint & Powder). The company isn’t expected to be operational until 2008, but it could provide a viable solution at that point.

If any of our readers has an idea regarding how to manage spent powder, we would love to hear from you. E-mail me at askjoepowder@yahoo.com.


Ask Joe Powder is a regular feature of Finishing Today magazine. Please send your questions to askjoepowder@yahoo.com.