Color coated coils use hot-dip galvanized sheets, hot-dip galvalume sheets, electro-galvanized sheets, etc. as substrates. After surface pretreatment (chemical degreasing and chemical conversion treatment), one or several layers of organic coatings are coated on the surface, and then A product that is baked and solidified. Colored steel coils are named after being coated with organic coatings of various colors, referred to as color-coated coils.
The anti-corrosion effect of architectural color-coated products is the combination of coating, pre-treatment film and coating (primer, topcoat, backcoat), which directly affects its service life. From the perspective of the anti-corrosion mechanism of color coatings, organic coatings are an isolation material that isolates the base material from corrosive media to achieve anti-corrosion purposes.
Factors affecting the use of PPGI steel coils
PE: The polyester coating has good adhesion to the galvanized steel plate. The coated steel plate is easy to process and shape, is cheap and has a wide range of product colors. Under direct exposure to the general environment, its corrosion life can reach 5-8 years. However, in industrial environments or polluted areas, its service life will be relatively shortened.
SMP: In order to give full play to the characteristics of polyester coatings and improve their outdoor durability and gloss retention, polyester coatings are modified into silicone-modified coatings through cold blending or thermal reaction. SMP has better durability and 10-12 years of corrosion protection, but its price is slightly higher than PE, and its adhesion and molding properties are worse than PE.
HDP: HDP is a resin with a higher molecular weight. The polymer has fewer branches, stable bond energy, and is not easy to actinize. Therefore, it is not easy to powder and reduce gloss. HDP uses the same inorganic ceramic pigment as PVDF, and the product has excellent retention properties. It has good color properties, UV resistance, outdoor durability and powder resistance, and is cost-effective.
SRP: It has excellent resistance to resin degradation under long-term sunlight and high temperature environments, and has excellent durability, but has high hardness.
PVDF: Due to the strong bond energy between PVDF chemical bonds, the coating has very good corrosion resistance and color retention. Among the color-coated steel plate coatings used in the construction industry, it is the highest product, commonly known as "color plate" "King". Its molecules are larger and have a linear chain structure. Therefore, in addition to chemical resistance, its mechanical properties, UV resistance and heat resistance are also excellent. Under normal circumstances, its anti-corrosion life can reach 20-25 years. But the cost is higher, and the price of color-coated steel plates is also higher, and its gloss can only be low gloss, with many restrictions. Color selection (bright colors cannot be provided).
