Powder coating, being a finishing medium that is applied as a free-flowing dry powder, has been around a lot longer than many people realize. The fact that powder coating possesses a slew of advantages over traditional wet paint, and being far more eco-friendly than traditional paint, would make one believe that powder-coating is fairly new; but the contrary is true. If we go back to the late 1940’s we find the application of organic polymers, in powder form, being utilized. By the time the 1950’s emerged, powders were flame-sprayed on metallic substrates.
Powder Coating Forges Ahead
If we want to give credit to the real advancement in powder-coat applications, it would go to a German scientist, Dr. Erwin Gemmer, who was visionary and looked beyond the 1950’s flame-spraying application method. He developed what is called ‘fluidized bed application’ for thermoplastic resins on metal. The process looked like this:
*** parts were pre-heated
*** organic coatings were applied
*** parts were immersed in a tank of finely-divided plastic powders
*** the plastic powders were held in a suspended state via a rising current of air
Dr. Gemmer’s fluidized bed application proved to be a much more efficient procedure than flame spraying, not to mention that flame spraying was extremely dangerous. With the proof in the pudding, a patent for Dr. Gemmer’s new application process was filed in Germany in May of 1953; and in September of 1955, the patent was issued. From then on, at least until 1965, almost all powder coatings were applied using Dr. Gemmer’s fluidized bed procedure.
As with all new and successful inventions, powder coating being used as a finishing product found itself absolutely surging ahead throughout America and Europe. There was one small issue, however: powder coating’s applications in various industries was very limited for commercial use. Due to that limited usage, other powder coating application methods were being introduced that would allow for a much wider range of applications.
A Broader Range of Powder Coat Uses
It was during the 1960’s that electrostatic powder spray emerged in the US and Europe; and during the 1970’s additional refinements to powder coat, via the ‘slurry’ application, came into play. Here, already-processed powder coatings were dispersed to a greater degree and, then, ground in a sand mill with water and surfactants being added to the mix.
Due to the advancements in powder coating, the applications for using this product, today, are quite stunning. Aside from metal, powder coat can be applied to wood, plastic, composites, glass, plastics, MDF and even some paper! Temperatures are modified to accommodate the delicateness of some materials since damage would, otherwise, occur with extreme heat. And for materials that are not electrically conductive, pre-heating in an oven is necessary. When the powder hits the heated area it will, slightly, melt on contact and effectively adhere. The non-electrically-conductive item is, then, placed back in the oven and cured.
From baby cribs, fire pits, and handguns to car/truck/motorcycle parts, plastic benches, and porch swings, powder coating is doing its part to make our world a lot more beautiful!