1. The choice of coated steel sheet mainly refers to the choice of mechanical properties, substrate type, coating weight, front color film performance, and back paint performance. Purpose, use environment, corrosiveness, service life, durability, processing method, and degree of deformation are important factors considered when selecting materials.
2. The mechanical properties are mainly selected according to factors such as use, processing method, and degree of deformation. When the strength requirement is not high, and the deformation is not complicated, the coated steel plate with common base material can be used. When the formability requirements are high, select the galvanized sheet substrate, and select the appropriate structural steel for the components with load-bearing requirements. Shearing, bending, and rolling are common forms of deformation of coated steel sheets. The mechanical properties may change with the color coating process and storage time, which may easily cause creases during processing. Pay attention to this.
3. The type of substrate and the weight of the coating are mainly selected according to factors such as the purpose, the corrosiveness of the use environment, the service life and the durability. Anticorrosion is one of the main functions of color-coated panels. The type of substrate and the weight of the coating are the main factors affecting corrosion resistance. Color-coated panels for construction usually choose hot-dip galvanized substrates and hot-dip aluminum-zinc alloy substrates. They should be used in corrosive environments. For substrates with good corrosion resistance and heavy coating weight, in addition, attention should be paid to the difference in corrosion resistance of substrate cuts when selecting substrates.
1. Front color film selection
1) Color film
Different types of color film have differences in hardness, flexibility, adhesion, durability, etc. PVC color film is currently the most used color film, with average durability, good hardness and toughness, and moderate price. The color film is mainly affected by the purpose, the corrosiveness of the use environment, the service life, the durability, the processing method, and the degree of deformation.
2) Primer
Different primers have certain differences in adhesion, toughness and corrosion resistance. Epoxy has good adhesion to the substrate and high corrosion resistance, but the toughness is not as good as other primers. Polyester has good adhesion to the substrate and excellent toughness, but its corrosion resistance is not as good as epoxy. Polyurethane is a primer with good overall performance. The primer is usually selected by the supplier according to the production process, use, corrosiveness of the use environment, and matching relationship with the topcoat.
3) Color film chromatic aberration
Color film will have color difference in production and use. Since the color difference is affected by many factors such as the production organization, color depth, use time, use environment, and purpose, it is usually negotiated by the supplier and the buyer when ordering.
4) Color film gloss
The choice is mainly based on the purpose and usage habits. Generally, low-to-medium gloss is selected for construction boards, and high gloss first is for household appliances.
5) Color film toughness/adhesion
This performance is closely related to the workability of the coated steel sheet and is mainly selected according to the processing method and the degree of deformation. When the deformation speed is fast and the deformation degree is large, the coated steel plate with high impact energy and small T-bend value is selected.
6) Durability
Durability is the performance of use, usually measured by the length of service life, and it is closely related to factors such as the type of color film, thickness, and corrosiveness of the use environment.
7) Other properties
The use environment requires that the coated steel plate has good solvent resistance, acid and alkali resistance, pollution resistance, and heat resistance. These requirements should be paid enough attention.
