Introduction of powder coatings

Powder coating is by far the youngest of the surface finishing techniques in common use today. Powder coating is the technique of applying dry paint to a part. The final cured coating is the same as a 2-pack wet paint. In normal wet painting such as house paints, the solids are in suspension in a liquid carrier, which must evaporate before the solid paint coating is produced.

In powder coating, the powdered paint can be applied by either of two techniques.

1. The item is lowered into a fluidised bed of the powder, which may or may not be electrostatically charged, or
2. The powdered paint is electrostatically charged and sprayed onto the part.

And it is finished to the surface by under two ways:

1. Thermoplastic powders that will remelt when heated, and
2. Thermosetting powders that will not remelt upon reheating.
   During the curing process (in the oven) a chemical cross-linking reaction is triggered at the curing temperature and it is this chemical reaction which gives the powder coating many of its desirable properties.