Color-coated coil has light weight, beautiful appearance and good corrosion resistance. It is mainly used in advertising industry, construction industry, home appliance industry, electrical appliance industry, furniture industry and transportation industry. According to the different use environment, it is divided into three types: hot-dip galvanized substrate, hot-dip aluminum-zinc substrate and electro-galvanized substrate. Due to different environments, the service life is relatively different. Today, we will take a closer look at the factors that affect the service life of color-coated plates?
On the basis of galvanizing, color-coated coils are treated with surface cleaning and chemical conversion film, and then coated with primer (focusing on adhesion and anti-corrosion) and topcoat (focusing on weather resistance and decoration), and two dense organic coatings. The protective barrier effectively prevents the penetration of water molecules and corrosive media, and has the ability to resist the destruction and decomposition of natural light such as ultraviolet rays. The thickness of the coating must reach the specified film thickness to obtain a dense shielding film, reduce water and oxygen permeability, and prevent corrosion of the coating. For the same type of paint, the thickness of the paint is a key factor affecting corrosion.
When the thickness of the coating is less than 10μm, the corrosion resistance often cannot reach 500h; in the interval of 10～20μm, after the same test cycle, increasing the thickness of the coating has a significant effect on reducing the corrosion level of the coating; between 20～26μm At the same time, the corrosion level of the coating increases with the thickness, and the change is not obvious; and the control difficulty of the coating process will increase with the increase of the thickness. The coating above 26μm is prone to unfavorable phenomena such as thickening of the edges; it can be seen from Comprehensive evaluation of cost and performance, 20μm is a lower value for achieving good and atmospheric corrosion resistance.
Post time: Jul-05-2022
