MIke:
Sorry about the delay in replying to your post, but I tend to have a delay
in reading the digest.
Paint and powder coating are very different.
Paint consists of a resin dissolved in a solvent of some type (toluene,
xylene, mineral spirits, ect.) which makes the resin a liquid and allows
you to apply the paint to a surface by brushing or spraying. The resin is
the material which forms the paint film when the solvent evaporates. This
type of paint is commonly refered to as alkyd or solvent based paint.
Latex paint consists of an emulsion of latex (acrylic, polyvinyl alcohol,
ect.) in water. When the water evaporates, the latex particles form a film.
Powder coatings, as the name implies, are supplied in powder form. The
resin is supplied as a powder without solvent to make it liquid. The powder
coating is sprayed by air pressure (not unlike a paint sprayer) onto the
electrically charged surface of the object to be coated. This electrostatic
charge holds the powder in place. The part is then placed in an oven. The
heat of the oven melts the powder (picture the way plastic melts) and the
now liquid coating adheres to the surface much like traditional paint.
Equipment to apply powder coatings costs hundreds of thousands of dollars
and consists of both equipment to apply the powder and ovens to cure the
coating.
Powder coating is typically used on OEM type applications. This is because
the surface of the object to be coated must be in perfect condition for the
powder coating to adhere properly. Also, due to the expense of the
application equipment, powder coatings are most cost effective for long
production runs of the same color and style.
Hope this helps. Many people in the paint business are confused on this
subject!
Ed Lancaster
74 TR6
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