Coil coating is a continuous industrial process
Coil coating is a continuous industrial process in which multiple layers of organic film are applied and cured on a moving metal strip. The paints used are liquid (solvent-based) and are generally composed of polyesters with acid- or hydroxy- endgroups able to crosslink with melamines or isocyanates to form a complete network with film properties that are tailored to the final application of the coated metal panel (building products, beverage cans, domestic appliances, etc.).
The total film thickness is around 5 to 25 µm, which allows for perfect color matching, surface hardness and transformation of the flat panel through bending or shaping without damage. The paints that are used for this application are usually based on a thermoset system involving catalyzed chemical reactions at temperatures around 240°C.
The main advantages of coil coating are its fast cure time – approximately 25 seconds – and its ability to create an already-painted substrate that is flexible enough to fabricate parts.