Coating steps for Colored aluminium sheet


Colored aluminium sheet, due to its good processability […]

Colored aluminium sheet, due to its good processability and good corrosion resistance, is increasingly used in building decoration, packaging, household appliances, automobiles, etc. The key factor that determines the quality of a colored aluminum plate is its coating.In fact, the same coating may show different properties based on changes in coating thickness, chromatic aberration, and selected gloss.

Generally, a colored aluminum plate is applied in two layers before completion. The first layer, called the topcoat, is usually polyester or a relatively improved product. Different finishes have different hardness, adhesion and corrosion resistance. As the most commonly used polyester, polyester has high hardness, strong adhesion, universal durability and medium price. Silicon-modified polyesters cover polyesters in terms of gloss and color durability, but their adhesion is weak. High durability polyester combines the advantages of both, and has the best cost performance. PVDF has excellent durability and good adhesion, but has lower hardness, less color, and is expensive. The other layer of the coating is called an undercoat and includes epoxy, polyester, and PU. These coatings also differ in adhesion, flexibility and corrosion resistance. Compared with other primers, aluminum plate has strong anti-corrosion ability. Polyester has good adhesion and flexibility, but poor corrosion resistance. PU becomes the best in overall performance. The performance of colored aluminum plate coating is affected by its application, environmental corrosion, durability, processing method, degree of deformation, etc.

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