A Few Thoughts about Powder Coating

Tuesday, March 13, 2012 | Blog

 

Powder coating is the process of applying dry powder paint to something; a part, a piece of equipment, an automobile – you name it and it can probably be powder coated.  A fairly young finishing technique, powder coating made its debut in Australia in the 1960s.

The powder coating process involves three basic steps; part preparation, powder application, and curing. 

Part preparation

The first, and most important step, is essential to any good coating.  Removal of oil, soil, lubrication greases, metal oxides, and welding scales can be done by a variety of chemical and mechanical methods. Which method is chosen depends on the size and the material of the part to be powder coated, the type of soil to be removed and the level of performance required of the finished product.

 

powder_coat_gunPowder application

In most cases, powder coating is sprayed onto an object through an electrostatic gun, or coronagun.  The gun imparts a positive electric charge on the powder, which is then sprayed towards the object by compressed air and then accelerated toward the piece by the powerful electrostatic charge.  The object is then heated, which melts the powder into a uniform film, and is then cooled to form a hard coating.  It is also common to heat a metal first and then spray the powder onto the hot object.

 

Curing powder_coat_yellow_blocks

 

The curing process, called crosslinking, is the third and final step.  When the powder is exposed to high temperatures, it melts, flows out, and then chemically reacts to form a polymerin a network-like structure. This process requires a certain temperature for a specific length of time in order to reach full cure.  Normally the powders cure at 200°C (390°F) for 10 minutes. 

 

So why not just use good ol’ fashion liquid paint?  Well, for a lot of reasons actually…

  • Powder coatings emit zero, or near-zero volatile organic compounds, which are hazardous to human health and the environment.
  • Powder coatings can produce much thicker coatings without running or sagging.
  • Powder coating overspray can be recycled, making it possible to use nearly 100% of the coating.
  • Capital equipment and operating costs are generally less than conventional liquid lines.

We found there are a lot of powder coating service providers all across America, big to small, servicing many different industries.  We have a pretty good database so if you are looking for a shop that can help you with a coating project give a call and we’ll pass along some names near you.

Pretty cool, huh?    

Based in Buffalo NY, Blackbird Asset Services is a boutique auction and valuation firm that caters to secured creditors and bankruptcy professionals. With a national practice, our auctioneers and appraisers work all over North America and conduct USPAP certified appraisal reports as well as on site and online auction sales.