Powder coating consists in principle of the same main ingredients as a wet-paint system, except for the solvent used in many wet processes. The sought-after properties come from the binder, curing agent, pigments and additives. The standard binder is epoxy, polyester or a mixture of the two. The powder coat is first charged electrostatically, then sprayed on the product, and achieves its final consistency by being melted and cured in a curing oven at temperatures of 180-200°C.
It is crucial for coat durability that pre-treatment is carried out correctly. To achieve the optimal durability, we place great store by giving the product the proper prepping in a modern, multistep dip facility. We use the most acknowledged chemicals on the market. For hot-zinc products we apply zinc manganese phosphate.
This prepping is the key to the coating system. Since no coat can be diffusion-proof, the prepping pacifies the metal surface, thereby inhibiting corrosion.
Application of powder
Following chemical pre-treatment the objects are dried in an oven and strung up on a conveyor belt. The powder is given an electrostatic charge using special guns, and blown towards the earthed object, which, thanks to the potential difference, attracts the powder. As the attraction is equally spread over the entire surface, the powder automatically forms an even coat.
Melt and cure
With the powder in place, the article passes through the curing oven where the coat first melts, then cures to a hard shell at 180 – 200°C.
As the objects emerge from the curing oven, they are first visually inspected, then measured for film thickness and glossiness.
Uses of powder coat
Powder coat can fulfil the most stringent standards in the market, both with regard to long-lasting corrosion resistance, chemical resistance, and finish. Powder coat, combined with the proper prepping, is ideal for hot-dip galvanized goods and aluminium, wherever robust anti-corrosion properties need to be combined with a decorative finish. Typical uses are for extrusion profiles, ironwork fittings, building sheet, stairs and railings, agricultural implements, park and street furniture, and many more applications.