Prepainted RAL3005 Matt Paint Galvanized Steel for the Fence Sheets

The surface treatment processes for color-coated aluminum sheets mainly include seven categories: roller coating, spraying (including fluorocarbon spraying/electrostatic powder coating), anodizing, film coating, heat transfer printing, wire drawing, and wood grain color coating. Among these, roller coating is the most mainstream and industrialized surface treatment method for color-coated aluminum sheets, while anodizing is mostly used for high-end decorative materials without coatings, such as "colored anodized aluminum sheets." Process Classification and Core Characteristics Surface Pretreatment (Common basis for all coating processes) Regardless of the main process used, strict pretreatment must be completed first to ensure coating adhesion and durability: Degreasing and Cleaning: Removes oil and dust, commonly using bio-enzyme degreasing agents or a combination of alkaline washing and acid washing; Chemical Conversion Film Treatment: Such as chromating or phosphating, forming a dense film layer on the aluminum surface, improving corrosion resistance and paint film adhesion; Key Control Points: Temperature (e.g., chromating requires 20±2℃), time, pH value, and subsequent coating must be completed within 4 hours after sandblasting. For long-term outdoor use (such as curtain walls), fluorocarbon spraying or roller-coating PVDF is preferred (strongest weather resistance); for interior decoration/cost-sensitive applications, choose roller-coated PE or laminated panels.