What Kind of Colour Coated Aluminium Coil Can Be Called Quality?

 Judge the quality of colour coated aluminium coils

1. Substrate quality

High quality colour coated aluminium coils are usually made from aluminium of higher purity or specific aluminium alloys as the substrate.

Material and alloy selection

Purity and alloy type: Prefer high purity aluminium (e.g. 1-series pure aluminium) or corrosion-resistant alloys (e.g. 3-series aluminium-manganese alloy, 5-series aluminium-magnesium alloy). 3003/3105 (manganese-containing) is suitable for conventional architectural shading, while 5052/5754 (magnesium-containing) is more corrosion-resistant and is suitable for coastal or high humidity environments.

Thickness uniformity:

The thickness of the substrate is uniform and the tolerance is controlled within a small range. For example, the common architectural colour coated aluminium coil thickness tolerance is generally controlled within ± 0.05mm, which ensures that the performance of all parts of the aluminium coil is consistent during processing and use.

Surface flatness:

the surface of the substrate should be flat and smooth, without obvious defects such as waves, bumps or roll marks. A substrate with high flatness is conducive to the uniform application of subsequent coatings, and it can better show the appearance effect in use.

2. Coating performance

Adhesion:

There should be good adhesion between the coating and the substrate, and the coating should not be peeled off or peeling phenomenon through the scratch test and other methods of detection. High-quality colour coated aluminium coil adhesion level can generally reach grade 0 (no shedding of coating) is excellent, grade 1 (small part of edge shedding) is acceptable, grade 2 and below is unqualified.

Corrosion resistance:

good resistance to salt spray, acids and alkalis and other corrosive properties. For example, after neutral salt spray test, in the specified time (e.g. 1000 hours), the surface of the coating has no obvious corrosion, blistering or rusting, etc., which is suitable for different use environments.

Weather resistance:

the coating is not easy to fade, chalking or cracking under long-term exposure to outdoor environment. High-quality colour coated aluminium coils are usually coated with high-performance coatings such as fluorocarbon (PVDF), which are weather-resistant and can ensure good appearance and performance for 20 years or even longer.

Gloss and colour accuracy:

The gloss of the coating meets the product requirements and the colour is uniform and consistent, with the colour difference from the standard colour card controlled within a very small range. For example, for some architectural colour coated aluminium coils, the gloss deviation is generally controlled within ±5%, and the colour chromatic aberration △E value is controlled within 1.0 to meet the aesthetic requirements of architectural appearance.

3. Processing performance

Bendability:

When bending, the coating will not be cracked or peeled off. For example, the colour coated aluminium coil will be bent into a certain angle (such as 180 °), the bending radius meets the requirements of the relevant standards, the coating can still remain intact, suitable for the production of a variety of curved shapes of sun shading panels, architectural decorative components.

Stamping:

It can withstand stamping and other processing techniques, and the coating will not peel or crack during the stamping process, so it can meet the processing needs of making complex shapes of household appliance shells, decorative parts and other products.

Welding performance:

for applications that require welding, the colour coated aluminium coil will not suffer serious damage to the coating at the weld seam due to welding heat after welding, and the welding strength meets the requirements to ensure the overall quality and performance of the product.

4. Dimensional accuracy

Width and length:

The width and length of colour coated aluminium coils should meet the specified dimensional requirements, with tolerances controlled within reasonable limits. For example, the width tolerance is generally controlled within ±2mm and the length tolerance is controlled within ±5mm to facilitate installation and splicing during use.

Coil diameter and inner diameter:

the dimensional accuracy of the coil diameter and inner diameter is also very important to ensure that the compactness of the roll and the installation of the equipment on the adaptability. For example, common colour coated aluminium coils have an inner diameter of 508mm or 610mm, with tolerances controlled to within ±5mm.

5. Packaging Quality

Protective Packaging:

High quality colour coated aluminium coils are usually protected by good packaging materials, such as wrapping with plastic film or paper internally, and fixing with steel bands or paper corner protectors externally, so as to prevent them from being damaged by scratches, collisions and moisture during transportation and storage.

Clear marking: The marking on the package should be clear and accurate, including product specifications, models, colours, production batch, production date and other information, to facilitate user identification and traceability of product quality.