Powder coatings are a combination of the following raw materials-
• Resins- Polyester or Epoxy, this gives the powder its performance capabilities. Polyester for a durable finish with good resistance to UV and weather exposure. Epoxy for good chemical resistance however not suitable for external use.
• Curing agents- Help to bind the coating
• Additives- Various with a wide range of properties for example; degasser to help the air escape from the substrate during the curing process therefore helping to restrict pin holing.
• Tint pigments- For colour
• Titanium dioxide- White pigment used in all coatings, amongst other properties it helps to create brightness by dispersing light.
• Extenders- Reduce glossiness.
• Effect pigments- Mica (artificial metallic) for external applications as actual metal will oxidise. Aluminium for internal use only products.
Once the required ingredients have been pre weighed, they are dry mixed before being extruded. This process melts the mix, activating the resin and hardeners before it is rolled flat on a conveyorised belt. The now cool mix is broken down in to chips, ground and then finely sieved to ensure no large particles contaminate the powder.
Because no solvents are present, powder coating is an environmentally friendly and cost effective alternative to traditional liquid paints. Furthermore, as the application is done electrostatically, the paint is recoverable and therefore re-usable. With no drying times required as the hardening is oven cured, powder coated products are ready to use as soon as they leave the production line!