Standard and application for surface coating Technology on Aluminum coil

 Standard and application for surface coating  Technology on Aluminum coil 

Description:Aluminum coil surface treatment technology provides a wide range of properties to materials through chemical, electrochemical or physical methods to meet a wide range of needs, from basic corrosion protection to high-end optical functions. The selection needs to be combined with specific application scenarios (such as weather resistance, cost, and functional customization), and pay attention to environmental protection and intelligent trends. For example, the construction industry prioritizes electrophoresis/powder coating, the optical sector relies on precision coatings, and the packaging industry focuses on efficient roller coating and food-grade safety. In the future, with the integration of new materials and processes, the surface treatment of aluminum coils will evolve in depth in the direction of multi-functional integration and sustainable development.

The surface treatment of aluminum coil is a key process to improve its performance, aesthetics and applicability, which mainly includes the following types of technologies and their application scenarios:

Core process and technical standards

Anodizing:

Standard: ISO 7599 (anodizing film thickness and testing), GB/T 5237.2 (specification for anodizing film for architectural aluminum profiles).

Parameters: film thickness 5-25μm, hardness HV 200-400, salt spray resistance test ≥ 1000 hours.

Chemical Conversion Treatment:

Standard: MIL-DTL-5541 (chromate conversion film), GB/T 17460 (chromium-free conversion film).

Parameters: film thickness 0.5-3μm, neutral salt spray resistance ≥ 72 hours.

Electrophoretic coating:

Standards: JIS K6828 (electrophoretic coating performance), HG/T 4848 (aluminum electrophoretic coating specification).

Parameters: film thickness 15-30μm, gloss ≥80%, weather resistance (QUV test ≥ 2000 hours).

Optical Coating:

Standards: ISO 9211 (Durability of Optical Coatings), GB/T 8013 (Reflectivity and Uniformity of Layers).

Parameters: reflectivity≥95% (specific wavelength), adhesion (grid method≥4B).

Performance improvement and industry applications：

Construction Industry:

Treatment technology: anodizing + powder coating.

Application: curtain wall aluminum panel (weather resistant, color stable), roof cladding (corrosion resistance, light weight).

Packaging industry:

Treatment technology: roller coating (food grade coating), chemical conversion.

Application: cans (acid and alkali resistant), pharmaceutical packaging aluminum foil (moisture-proof, non-toxic).

Electronics & Optics:

Processing technology: optical coating (AR/IR coating), anodizing.

Application: Mobile phone screen (anti-reflective), laser mirror (high reflectivity), heat sink (insulation).

Automotive Industry:

Treatment technology: electrophoretic coating + chemical conversion.

Applications: Body panels (scratch resistant), battery housing (anti-corrosion, insulation).

Technology comparison and selection suggestions：

Future trends and innovation directions：

Green Process:

Chromium-free conversion film and water-based coating replace traditional solvent-based materials to reduce environmental pollution.

Composite Coating Technology:

Nano coatings (e.g. graphene, SiO₂) improve antimicrobial, self-cleaning functions (e.g. medical devices, kitchenware).

Intelligent Production:

The on-line detection system (real-time monitoring of film thickness and color difference) improves the uniformity and consistency of the coating.

Functional Integrations:

Photovoltaic aluminum coils (surface coating + solar absorbing layer) are used in building-integrated photovoltaic systems (BIPV).