The metal aluminum plate itself has only one color, but many treatments can be done on its surface. It can form colorful colors on the surface of the aluminum plate through spraying, roller coating, wood grain, cloth grain and other processes. Fluorocarbon paint is highly praised by the building decoration industry for its wide range of color selection, excellent weather resistance and corrosion resistance. With the rapid development of coating technology, the excellent performance of fluorocarbon coating makes it more and more widely used in building decoration materials. Today, let's take a deep look at the difference between fluorocarbon spraying and fluorocarbon roller coating processes, and what types of aluminum plate materials they are suitable for application.
Fluorocarbon spraying Fluorocarbon spraying is an electrostatic spraying method, which is also a liquid spraying method. It refers to a coating method that uses the principle of corona discharge to make the atomized coating negatively charged under the action of a high-voltage DC electric field, and adsorbs on the surface of a positively charged substrate for discharge. For example, the common aluminum veneer we use is first processed and formed according to the drawings, then polished and cleaned, sent to the cleaning tank for alkali washing and pickling, and then sent to the spray paint room for spraying and baking, forming a spray layer on the surface to isolate the outside air and pollutants from directly corroding the substrate. The fluorocarbon spraying process mainly includes three steps: pretreatment (degreasing, pickling, chromization), spraying and curing (baking). According to the needs of material coating, two coatings, three coatings or four coatings can be selected. Two coatings (primer + topcoat); three coatings (primer + topcoat + varnish); four coatings (primer + barrier paint + topcoat + varnish). In general, the average thickness of the two-coat coating is ≥30μm, and the average thickness of the three-coat coating is ≥40μm.
Fluorocarbon roll coating
Fluorocarbon roll coating is a coating method that uses a rubber roller or a steel roller to apply paint on the surface of the aluminum plate, so that the paint is leveled and arranged, and finally evenly transferred to the moving metal sheet (steel plate or aluminum plate) and then baked and cured, thereby forming an organic solid protective film on the metal sheet. Fluorocarbon roll coating is mostly used for surface treatment of metal sheet substrates, also known as pre-coating. For example, the common aluminum composite plate we have is usually placed on the production line for surface treatment, then roll-coated with fluorocarbon paint and baked to form a product. The roll-coated coil generally needs secondary processing and molding before use. The production process of fluorocarbon roll coating is to bake while coating, and generally it takes several times to bake several times. Commonly used methods are three coatings and three bakings or two coatings and two bakings. Under normal circumstances, the average thickness of the two-coating and two-baking coating is ≥25μm, and the average thickness of the three-coating and three-baking coating is ≥32μm.
The difference between fluorocarbon spraying and fluorocarbon roll coating processes is not only in their surface effects, but also in the obvious difference in the order of film formation and molding processes of aluminum plates. Spraying aluminum plate first processes the sheet metal into shape, which can be folded, carved, bent, welded, punched, etc. It is easy to shape, has strong plasticity and will not cause any impact on its surface. Fluorocarbon roller coating requires thin aluminum coils to be filmed first, which means that many processes will be restricted to avoid damage to the paint surface, and it is difficult to unify the color of the later repair. ▧ Advantages of fluorocarbon spraying process 1). The spraying process is carried out after the aluminum plate is formed. The small defects of the aluminum plate itself and the small defects added during the forming of the aluminum plate can be compensated by the spraying process. The spraying process has considerable flexibility. 2). The spraying construction process is mature and the coating performance is good. The thickness of the first film can reach 50~80μm, and the comprehensive indicators such as adhesion and corrosion resistance are relatively excellent. 3). The colors are diverse and can be made into various colors according to customer requirements, but the color system is relatively flat.
Advantages of fluorocarbon roller coating process 1). High-speed automated operation, fast speed, high production efficiency, no paint mist, and no paint mist splashing. 2). Roller coating is applied due to the pressure of the flat plate, the plate surface is evenly stressed, and the error of the paint film thickness is less than 0.5 microns. The thickness of the entire coating film layer is uniform and the error is minimal. The surface is smooth and delicate, without micropores and pollution. 3). The paint utilization rate reaches more than 99%, which is an efficient, energy-saving and environmentally friendly product with low loss. 4). Roller coating can print various patterns, including precious wood grain, marble grain, fantasy color and other special colors, and the types of sprayed colors are relatively flat. In addition, since the roller coating process is directional, the surface color will be different under the refraction of sunlight. Pay attention to keep the direction consistent during installation.
The fluorocarbon roller coating process shows obvious advantages in production efficiency, coating quality, full life cycle cost-effectiveness and environmental impact, while the fluorocarbon spraying process is an effective choice in certain specific application scenarios, such as processing aluminum plates with complex shapes. Therefore, when choosing a coating process, the most suitable process type should be selected based on multiple considerations such as specific project requirements, budget constraints and environmental protection requirements.
