The base material in color coated steel consists of steel, coated with a thin zinc layer. The steel is chosen with properties that will best suit the end product. For structural steel applications this follows standardized mechanical properties according to EN 10346. For applications where the steel should be formable in a demanding way or the product should be worked with by tinsmiths, extra formable steels are used.
The zinc coating protects the steel from corrosion in two ways. It is a protective layer keeping oxygen and water away from the steel, but it also acts as a cathodic protection. This means that at cut edges or in case of damages through the zinc coating, the zinc will sacrifice itself and react to form protective compounds andblock further corrosion processes.
The zinc coating is measured in weights per square meter and covers the steels on both sides.
The pre-treatment layer is applied to further improve the corrosion resistance, but also to give a good adhesion to the coating layer.
The primer layer is used for corrosion protection with corrosion protective additives and also acts to give a good adhesion to the top coat.
The top coat type is chosen to best fit the purpose of the application. It can be chosen to serve in different environments and also offer different appearances. This is also the layer that gives the final product its color.
A two layer backing coat protects the reverse side of the color coated steels. In this layer our GreenCoat® products are marked with a text that identifies GreenCoat® and SSAB as the original manufacturer.