Prepainted steel coil
Prepainted steel coils are based on hot-dip galvanized sheet, hot-dip galvanized sheet, electro-galvanized sheet, etc. After surface pretreatment (chemical degreasing and chemical conversion treatment), one or several layers of organic coatings are applied on the surface, and then A product that has been cured by baking. It is also named after the color steel coils coated with organic coatings of various colors, referred to as color coated coils. The color-coated steel strip using hot-dip galvanized steel strip as the base material is protected by the zinc layer, and the organic coating on the zinc layer plays a covering and protective role to prevent the steel strip from rusting, and the service life is longer than that of the galvanized strip.
Prepainted steel coil obtained by coating the organic coating on the hot-dip galvanized steel sheet with the zinc substrate is the hot-dip galvanized color-coated sheet. In addition to the protective effect of zinc, the organic coating on the surface of the hot-dip galvanized color-coated sheet also plays the role of insulation and protection, preventing rust, and the service life is longer than that of the hot-dip galvanized sheet. The zinc content of the hot-dip galvanized substrate is generally 180g/m2 (double-sided), and the maximum galvanized amount of the hot-dip galvanized substrate for building exterior is 275g/m2.
Prepainted steel coil coating type
Good adhesion, rich color, wide range in formability and outdoor durability, medium chemical resistance, low cost.
Silicon modified polyester
Namely (SMP), the coating film has good hardness, abrasion resistance and heat resistance, as well as good external durability and chalk resistance, gloss retention, average flexibility, and moderate cost.
High Durability Polyester
Namely (HDP), excellent color retention and UV resistance, excellent outdoor durability and chalk resistance, good film adhesion, rich color, excellent cost performance.
Namely (PVDF), excellent color retention and UV resistance, excellent outdoor durability and chalk resistance, excellent solvent resistance, good formability, dirt resistance, limited color, high cost.
Prepainted steel coil use
The hot-dip Al-Zn substrate adopts hot-dip Al-Zn steel sheet (55% Al-Zn) as the newly coated substrate, and the content of Al-Zn is usually 150g/㎡ (double-sided). The corrosion resistance of hot-dip galvanized sheet is 2-5 times that of hot-dip galvanized sheet. Continuous or intermittent use at temperatures up to 490°C will not severely oxidize or produce scale. The ability to reflect heat and light is 2 times that of hot-dip galvanized steel, and the reflectivity is greater than 0.75, which is an ideal building material for energy saving. The electro-galvanized substrate uses electro-galvanized sheet as the substrate, and the product obtained by coating organic paint and baking is electro-galvanized color-coated sheet. Because the zinc layer of the electro-galvanized sheet is thin, the zinc content is usually 20/20g/m2, so this product Not suitable for use in making walls, roofs, etc. outdoors. But because of its beautiful appearance and excellent processing performance, it can be mainly used in home appliances, audio, steel furniture, interior decoration, etc. about 1.5 times.