Every step significantly contributes to the excellent finished pre-painted aluminum coil, the pursuit of perfection spurs us on to our utmost effort to deal with every step as the following:

The coil coating process is the most efficient means of coating aluminum with an organic protective coating. It is a continuous, high-volume process that produces a consistent product in comparison to batch post-coating methods. The aluminum substrate gets degreased, chemically pre-treated and coated. Typical paint system requirements are formability, scratch-resistance, appearance, weatherability, printability, etc

Entry Section

The coil is fed to the line and leveled using a tension leveler which is used to ensure an absolutely flat product, the coil entry accumulator. There are two pay off reels, which ensures that a standby coil is always available. When the coil being processed has finished, the coil needs to stop to allow the end of this coil to be either stitched or welded to the leading edge of the new coil, the accumulator then empties to allow a continuous flow of material through the processing section to keep the subsequent process zones of the line running.

Cleaning and Pre-treatment

Pre-cleaning of the coil through cascade spraying in alternate directions within different zones, cleaning is thus much more efficient than conventional technologies and water can be re-used, thereby cutting consumption levels. Pre-treatment is essential to increase the corrosion resistance and ensure paint adhesion. The conversion layer is chemically built up on the surface of the aluminium coil during pre-treatment process, and HAOMEI is using the most efficient no-rinse technology to improve the quality, and eliminated wastes

Coil Coating

The coil coating process consists of two stages, one is called primer application and the other is finish coating application. In the first stage, the coil passes though a roller coater machine that applies a primer paint coat to both sides/one side of the coil. After curing and dried, the coil passes though a second roller coater machine which applies the finish coating to both sides/one side. There are essentially two different types of coating- decorative and functional and typical requiring formability, scratch resistance, appearance, weather resistance, printability etc. to achieve different results, the paint system are used: e.g. acrylic primer, polyester, PUR, or PVDF.

Curing

The strip again passes though an oven set at an appropriate temperature to ensure that all the volatiles are removed and that the paint is fully cured. Depending on the paint system, the curing temperature lies between 200~3000℃, and it is the key technology to promise the coating quality. What is more, in order to protect the environment and safe cost, the solvent vapour is burned- off and used to heat the ovens.

Further Processing

The coated aluminum coil maybe wind up or imprint a pattern into the paint surface by an embosser roll.

Quality Control

Lamination of Protective Film

A protective film is customized to apply to the HAOMEI pre-painted aluminum coil which protect the film and carry additional information such as coating direction and brand details. The films are environmentally friendly and easy to recycle.