PVDF Painted Aluminum Coil

PVDF painted aluminum coil belongs to high-grade color coated aluminum product, so the price is higher, and it has been used in foreign countries for a long time. In recent years, aluminum panel curtain wall has been widely used. Due to its excellent characteristics, it has attracted more and more attention from the construction industry and users. Fluorocarbon coating has excellent anti-fading, anti-blooming, anti-corrosion resistance to atmospheric pollution (acid rain, etc.), strong anti-ultraviolet ability, strong crack resistance and can withstand harsh weather environments. It is beyond the reach of general coatings.

pvdf painted aluminum coil is mainly used in aluminum curtain wall. In addition to the excellent mechanical properties of wear resistance and impact resistance, it shows long-term fading resistance and UV resistance, especially in harsh climates and environments, corrosion resistance. Aluminum coil itself has good corrosion resistance, and fluorocarbon spraying is generally not used on the surface of aluminum coil.

The fluorocarbon spraying process of pvdf coated aluminum sheet is: pre-treatment process: degreasing and decontamination of aluminum material → water washing → alkali washing (degreasing) → water washing → pickling → water washing → chroming → water washing → pure water washing Spraying process: spray Primer→topcoat→overcoat→baking (180-250℃)→quality inspection Multi-layer spraying process with three sprays (referred to as three sprays), spray primer topcoat, topcoat and topcoat and secondary spraying ( primer, topcoat).

Before spraying aluminum coil, the surface of the aluminum should be degreasing, decontaminated and chemically treated to produce a chromed film, increase the bonding force between the coating and the metal surface and the anti-oxidation ability. It is beneficial to prolong the service life of the paint film.

Primer coating: as a primer coating for a closed substrate, its function is to improve the penetration resistance of the coating, enhance the protection of the substrate, stabilize the metal surface layer, and strengthen the adhesion between the topcoat and the metal surface , which can ensure the color uniformity of the topcoat coating, and the thickness of the paint layer is generally 5-10 microns.

Topcoat: The topcoat is the key layer of the spray coating, which is to provide the decorative color required by the aluminum material, make the appearance of the pvdf painted aluminium coil meet the design requirements, and protect the metal surface from the external environment, atmosphere, acid rain , pollution erosion, prevent UV penetration. Greatly enhance the anti-aging ability. The top coat is the thickest layer of paint in spraying, and the thickness of the paint layer is generally 23-30 microns.

Overcoat paint coating: Overcoat paint coating is also called varnish coating. The main purpose is to more effectively enhance the paint layer’s resistance to external erosion, protect the topcoat coating, increase the metallic luster of the topcoat color, and improve the appearance The color is more vivid and dazzling, and the coating thickness is generally 5-10 microns. The total thickness of the three-spray coating is generally 40-60 microns, and can be thickened if required.

Curing treatment: The three-spray coating generally needs secondary curing, and the pvdf painted aluminum coil enters the curing furnace for treatment. The curing temperature is generally between 180 °C and 250 °C, and the curing time is 15-25 minutes. Different pvdf coated aluminum coil manufacturers will provide the best temperature and time according to their own paint.