Advantages & Disadvantages of Powder Paints...

Advantages
  • Unlike liquid paints, powder coating does not use any solvents...eliminating V.O.C.'s (Volatile Organic Compounds).
  • AAMA 2603 powders come with a 10-year factory warranty.
  • The mechanical durability of powder greatly exceeds wet paint.
  • Requires less energy to produce (Can be up to 30% less than liquid).
  • Excess powder in the application process can be reclaimed...eliminating waste.
  • Powder can be applied at higher film builds than liquid. 
Disadvantages
  • Difficult to touch-up in the field with a good color match.
  • Applicators cannot perform in-house blending and color matching.
  • Powder coating requires a greater film thickness and is difficult to achieve lighter film thickness without creating an orange peel effect.
  • Some powder paints are not as economical as their equivalent in wet paints.
  • Powder coat paints cannot provide the brillance of a metallic look as with liquid paints, due to powders inability to hold the same metallic flake content.
  • Single coat powder paints on aluminum are susceptible to filiform corrosion.

Types of Powder Paints...

There are (2) basic types of powder paints:

Thermoplastic - Powders that will remelt when heated

Thermosetting - Powders that will not remelt upon reheating (Keymark sprays only Thermosetting powder paints).

Types Of Thermosetting Powder Paints And Their Properties:

Types of Powder Paint


Property Standard Polyester Enhanced Polyester Epoxy Hybrid Polyurethane Acrylic PVDF
Exterior Durability Good Excellent Very Poor Poor Good Excellent Excellent
Corrosion Resistance Good Good Excellent Good Good Good Good
Impact Excellent Poor Excellent Excellent Good Poor Excellent
Flexibility Excellent Good Excellent Excellent Good Good Excellent
Adhesion Excellent Excellent Excellent Excellent Excellent Excellent Poor
Cost Medium Medium/High Medium Low Medium High High
Film Appearance Good Very Good Good Good Excellent Good Poor
Chemical Resistance Good Good Excellent Very Good Good Very Good Good
Gloss Range 10-95% 20-95% 5-90% 5-90% 5-95% 30-90% 30-60%
Heat Resistance Very Good Good Poor Good Very Good Good Good
Abrasion Good Good Very Good Good Good Good Poor

The Powder Coating Process...

  • Extrusions are loaded on racks and are submerged in a pretreatment tank (40 feet in length) containing chrome phosphate. Chrome Phosphate has proven to be the premier pretreatment for powder paints to ensure the highest level of performance and adhesion. This is also the most important part of the entire painting process.
  • Parts are dried in an infrared oven before the application process.
  • In the application process, the extrusions travel into the powder booth where powdered resins along with colored pigments are applied to the extrusions through the use of automatic spray guns and an electro-static charge.
  • The extrusions then enter a separate high temperature bake oven (350-425 degrees) for approximately 20 minutes and this causes the powder to melt, flow, and then cure, forming a molecular fusion bond.
  • The end result is hard surface to coating bonding unlike any other.