Pre-Treatment

A four stage pre-treatment process including a phosphate conversion coating is used by AMPC for the preparation of each metal surface. This, along with an essential cleaning procedure to eliminate surface soils and imperfections, ensures a perfect powder coated surface every time.

Preparation of Metals for Powder Coating

Proper and effective pretreatment is critical to a successful, long-life powder coated surface. Pretreatment of metals is done in order to eliminate the soils and imperfections on the substrate and then the creation of a surface for bonding.

The first step cleaning is essential, and the necessity for such operations increases with the quality of the product. The second phase of pretreatment is the preparation or conditioning of the surface for the powder coating. This is achieved by applying a phosphate coating that reacts with the metal surface, converting it into a dense, continuous layer of either crystalline or amorphous phosphate becoming is an integral part of the surface.

Phosphate coatings improve life in two ways:
1) By providing a surface more receptive to powder.
2) By preventing the spread of under-film corrosion resulting from damage to the powder film.

Powder adhesion is improved physically because the layer of phosphate crystals provides a better, more uniform footing than bare metal. In addition, there is a chemical affinity between the phosphate coating and the powder film.

No matter how excellent the quality of the powder applied to a steel product, rust can form between the powder film and the steel, unless the steel is protected with a phosphate coating.