As we are entering an era of conserving the environment; and powder coating, an environmentally friendly aluminium coating, increasingly becomes more relevant to the architectural aluminium coating requirements. The powder used in powder coating process is typically of the thermosetting type. There are different types of resins available in powder form for aluminium powder coating applications including epoxy, epoxy polyester, polyurethane, acrylic and polyester. Most of the high performance architectural powder coating powders in use today are based on the Carboxyl functional polyester polymers, which have outstanding toughness, exterior durability and abrasion resistance and are available with warranties of 10, 15 and even 20 years.
Aluminium powder coatings are solid paints ground into a fine powder. The finely ground powder is fluidized in a hopper with the help of completely clear dust and moisture free compressed air at low pressure. The fluidized powder is applied to the aluminium work surface by spraying it with an electrostatic spray gun. The powder particles are charged to a potential of around 60KV and are thus attracted to the aluminium work pieces. Once the powder, which is negatively charged, is sprayed on the positively charged aluminium profile, curing is done in a baking oven at a temperature of around 180°C to 200°C for 10-12 minutes, thereby fusing it with the aluminium surface and giving it a smooth finish.
The quality of the finished powder coating material is the result of both the powder quality and the powder coating process. As such, the first essential requirement of quality assurance in powder coating is the quality of the powder. The powder should have the requisite properties so that the film resulting from the application of the powder should be able to produce the desired surface, physical and environmental characteristics as per requirement of the customer. As long as the powder is coming from Akzo Nobel or Jotun, we are sure about the quality of the powder coatings.