The production of PVDF-coated aluminum coil has higher technical requirements than ordinary coated aluminum coils, especially in coating formulation and curing process. The main steps are as follows:

• 1
  High-Quality Substrate Selection Select high-purity aluminum coils with excellent surface quality, such as 1060, 3003, 5052, and 6061 alloys. The substrate's surface flatness, thickness uniformity, and impurity content are strictly controlled to avoid affecting the coating adhesion and appearance.
• 2
  Precision Surface Pretreatment This is the basis for ensuring long-term adhesion of PVDF coating, including three key links:

  Degreasing & Cleaning: Use alkaline degreasing agents and ultrasonic cleaning technology to completely remove oil, dust, and oxide layers on the aluminum coil surface, ensuring no residual contaminants.
• 3
  Chemical Conversion Treatment Adopt zirconium-based or titanium-based environmental protection conversion agents (replacing traditional chromate conversion) to form a dense, uniform conversion film with a thickness of 0.5–1μm, which enhances the bonding force between the substrate and the coating.
• 4
  Low-Temperature Drying Dry the pretreated aluminum coil at 100–120°C to remove surface moisture, ensuring the conversion film is stable and not damaged.
• 5
  PVDF Coating Roller Coating Use multi-layer roller coating technology, usually including primer, topcoat, and optional backcoat. The PVDF content in the topcoat is ≥70% (meeting AAMA 2605 standard). The coating thickness is precisely controlled: primer 5–10μm, topcoat 20–30μm, backcoat 5–10μm. The roller coating speed and pressure are adjusted in real-time to ensure uniform coating thickness.
• 6
  High-Temperature Curing Send the coated aluminum coil to a high-temperature curing oven with precise temperature control. The curing temperature is 230–250°C, and the curing time is 25–35 minutes. This process promotes the cross-linking polymerization of PVDF resin, forming a dense and stable coating structure.
• 7
  Strict Quality Inspection Conduct comprehensive testing of key indicators, including coating thickness (using a coating thickness gauge), adhesion (cross-cut test ≥5B), pencil hardness (≥3H), color difference (ΔE ≤1.0), weather resistance (QUV aging test ≥3000 hours), and corrosion resistance (neutral salt spray test ≥1500 hours). Unqualified products are strictly eliminated.
• 8
  Slitting & Packaging According to customer needs, slit the qualified PVDF-coated aluminum coil into coils of different widths, and use moisture-proof, scratch-resistant packaging materials (such as PE film, corrugated cardboard, and wooden pallets) for packaging to ensure product integrity during transportation.

PVDF-coated aluminum coil specifications are customized according to high-end application scenarios and performance requirements. The main specifications are shown in the following table: