The base material of the color-coated coil can be cold-rolled coil or hot-plated steel. Although the organic coating part of the color coated coil has a good anti-corrosion effect, there are still some small gaps in the organic coating, and air and moisture may enter, which may lead to rust of the substrate. As a result, color-coated coils made from uncoated substrates have a shorter service life and are prone to spread and cause the coating to peel off after being scratched. The base material of the color coated sheet coil is mainly galvanized steel plate or galvanized metal alloy steel plate technology. In some production lines, the production process of color coatings is divided into substrate pretreatment, chemical conversion film (non-organometalic paint), organic non-metallic paint and post-coating process.

If we are not a galvanized steel plate as a substrate, we can directly enter the society economically after production, it may continue to rust (white rust), dust, and other pollution in the process of transportation development. If these cannot be removed, the quality of the paint will suffer. The quality of the finished color coated rolls and the physical, chemical and technical properties of all students are closely concerned with the pretreatment. In addition, in the galvanizing production, in order to prevent rust and oil, these oils are also removed before the color coating production. Now we use more pretreatment method for alkali solution degreasing method.

Second, the chemical conversion membrane has two effects

First, to further improve the anti-rust capacity,

The second is to improve the adhesion between the substrate and the coating, and improve the coating performance of the substrate.

There are generally three steps:

One is phosphating, forming a large number of crystals on the metal surface, and then using phosphorus salt solution to form a phosphate film on the metal surface;

The second is passivation and closure, the phosphate film still has some holes, and the chemical reaction between the chromate and the hole points is used to form a protective film. Third, wash with pure water and remove the passivation solution with desalted or deionized water.

Organic coating Organic coating is mainly divided into primer and top paint, primer requirements are not high, you can color smooth coating, but now the development of Chinese enterprises in order to improve production information security, primer paint is generally color reverse coating.

Post-coating process: The post-coating process includes printing, embossing, peeling protective film, laminating, etc., which improves the decoration and protection of the color coating plate. In addition, for some post-coating technology abroad, there is a process such as leveling and straightening used in cold rolling and galvanized processing lines.