pretreatment chemicals

Sand Blast or Shot Blasting

Substrate pretreatment:
At this stage of the process, the goal, as with conventional systems, is to remove dirt, rust, oils, and grease from the surface to be painted, allowing the paint to adhere to the surface.

The pretreatment process used will depend primarily on the type of contamination present on the surface and the specifications requested for the final product.

Jet Polishing:

The purpose of this process is to remove residues adhering to the surface, being very efficient in removing rust.

It can be used with sand or steel shot; the choice of particle size or type of the abrasive material is very important to avoid excessive damage to the surface.

This process produces excellent cleaning results, but only removes contaminants on the surface.

Degreasing:

Degreasing with chlorinated solvent vapors (trichloroethylene or trichloroethylene) is very efficient in removing grease, but the part should not show any rust.

In addition to being highly efficient, this process can be automated and incorporated into the painting system. Its main feature is optimal penetration into all parts, producing a highly uniform cleaning.

Pickling or deoxidation:

Pickling or deoxidation refers to the removal of rust particles present on the surface of the substrate to be painted. There are three levels of oxidation: light, with dusty rust on the surface that is easily removed; moderate, with dusty rust on the surface that is somewhat difficult to remove; and severe, with scale on the surface that can only be removed by sanding, sandblasting, or shot peening.

Pickling or deoxidation is done with alkaline or hydrogen sulfide acid vapors. This process is the most efficient as it eliminates light and moderate oxidation from the surface with perfect penetration into all points of the parts.

Phosphated:

This process involves applying a layer of phosphate to the surface to be painted. It is the most efficient process, as it eliminates all surface contamination with perfect penetration into all areas of the parts.

The process consists of a sequence of baths, which ultimately leaves the surface clean with a thin film of zinc or iron phosphate.

Seal:

This process refers to the passivation of the oxidation resulting from the phosphating process. It is carried out by depositing a layer of chromic or organic seal, which allows for the achievement of a layer that is highly resistant to corrosion for 36 to 48 hours, in addition to improving the adhesion of the paint on the metal substrate to be painted.