Lacquered aluminum coil, also known as painted or coil-coated aluminum coil, is aluminum strip that is continuously coated with an organic lacquer or paint and cured on a coil-coating production line.
The process combines the low density, corrosion resistance, formability, and recyclability of aluminum with the decorative and protective properties of an organic coating. Compared with painting individual finished parts, coil coating provides consistent surface quality and efficient large-volume production.
Lacquered aluminum coil is used for packaging, building products, appliances, HVAC components, lighting products, and other applications where a controlled color and finished surface are required.
1. Common Base Alloys
| Alloy | Typical Characteristics | Typical Applications |
|---|---|---|
| 1050 / 1060 | High aluminum content, excellent formability | Decorative products, packaging and formed components |
| 3003 / 3004 | Higher strength with good formability | Building products, appliance components, HVAC applications |
| 8011 | Good formability in thin gauges | Packaging and coated foil products |
| 1235 | High formability, commonly supplied in foil gauges | Thin coated foil and packaging applications |
The base alloy should be selected according to the required strength, forming operation, thickness, corrosion environment, and end use. For food or pharmaceutical packaging, the coating system and regulatory compliance are just as important as the aluminum alloy.
2. Coating Systems
Several coating systems are available depending on the required performance.
Polyester coating is widely used for general architectural, industrial, and indoor applications. It provides good flexibility, color selection, and surface protection at a relatively competitive cost.
PVDF coating is commonly selected for demanding exterior architectural applications because of its strong resistance to UV exposure, weathering, and color fading. The actual service life depends on resin formulation, coating thickness, pretreatment, environment, color, and installation conditions, so a fixed service-life guarantee should not be assumed without a specified coating system and test data.
Epoxy coatings provide good adhesion and chemical resistance and can be used as primers or for selected interior applications.
Some products use a primer plus topcoat, while others use a single-coat system. Two-sided coating can also be supplied where both surfaces require protection.
Coating is normally applied by continuous roll coating, followed by controlled curing in an oven. Typical dry-film thickness depends on the coating type and project requirements. As a general reference, architectural front coatings may be approximately 15–30 μm, while backer coatings are often thinner.
3. Typical Specifications
| Parameter | Typical Range |
|---|---|
| Aluminum Thickness | 0.2–1.5 mm |
| Width | 800–1,600 mm |
| Wider Width | Available depending on production capability |
| Coil ID | 508 / 610 mm |
| Coil Weight | Approximately 1–8 tons |
| Front Coating | Typically 15–30 μm |
| Back Coating | Typically 5–15 μm |
| Surface | Smooth, embossed, or customized |
| Color | RAL or customer-specified color |
Actual dimensions and coil weight should be confirmed according to the supplier's production equipment and the customer's requirements.
4. Performance and Quality Testing
Coated aluminum coil should be evaluated according to the requirements of the coating system and end application.
Common quality checks include:
Coating adhesion: Cross-cut or similar adhesion testing
Flexibility: T-bend testing according to the applicable coating specification
Surface hardness: Pencil hardness or another specified method
Color consistency: Instrumental color measurement such as ΔE
Gloss: Gloss measurement where required
Coating thickness: Verification of dry-film thickness
Corrosion resistance: Salt-spray or other environmental testing when specified
Accelerated weathering: QUV or equivalent testing for exterior applications
Values such as T-bend, hardness, ΔE, and salt-spray hours should be agreed before production because different coating systems and standards have different acceptance criteria.
5. Applications
Building and Construction
Lacquered aluminum coil is used for roofing components, flashing, facade accessories, wall cladding, ceiling systems, gutter components, roller shutters, and architectural profiles.
Appliances
It can be processed into panels and components for refrigerators, washing machines, air-conditioning equipment, ventilation systems, and other household appliances.
Packaging
Coated aluminum is used for selected can ends, closures, caps, containers, and other packaging products. For direct food contact, the coating must comply with the relevant food-contact regulations in the destination market.
Lighting and Decorative Products
Reflectors, signage, decorative panels, and other formed components can use lacquered aluminum because the coating provides both appearance and surface protection.
6. How to Specify Lacquered Aluminum Coil
When requesting a quotation, provide the supplier with:
Base alloy and temper
Aluminum thickness and width
Coil ID and approximate coil weight
Coating type
Front and back coating thickness
Primer requirements
RAL or custom color
Surface finish
Forming requirements
Applicable standard
Quantity and packaging requirements
For architectural applications, customers should also specify the required weathering performance and coating system.
Before mass production, it is recommended to confirm the base material certificate, coating thickness, color, gloss, adhesion, flexibility, surface quality, and applicable test reports. This helps ensure that the lacquered aluminum coil meets both the visual and technical requirements of the final product.
