How to Choose the Back Paint for Color-Coated Sheets?

Many downstream users typically focus on the selection of the topcoat while neglecting the back paint. So, how can we select the appropriate back paint based on different usage environments?

Currently, epoxy back paint is the most commonly used option. Its greatest advantage lies in its excellent corrosion resistance, making it suitable for both composite sheets requiring strong adhesive properties and single-layer sheets. However, epoxy back paint has poor aging resistance. For environments with severe corrosion, the thickness of the epoxy back paint can be appropriately increased. Yet, due to the limitations of epoxy coating thickness, it is also advisable to add an additional layer, such as a polyester coating, high-weather-resistant coating, or fluorocarbon coating, as needed.

Of course, for special environments, specialized coatings should be selected based on the corrosion source. For example, livestock-specific coatings are required to resist penetration and corrosion from animal feces. However, the double-layer back coating structure is more applicable to single-layer sheets or on-site composite applications.