Metal pretreatment chemicals are chemical products used to clean and prepare a metal surface before painting, powder coating, plating, anodizing, or other finishing processes. Their purpose is to improve coating adhesion, corrosion resistance, and the overall quality of the finished product.
* Main Types of Metal Pretreatment Chemicals
1. Cleaners / Degreasers
Remove oil, grease, dirt, and contaminants.
Can be alkaline, acidic, or solvent-based.
Usually the first step in pretreatment.
2.Pickling Chemicals
Remove rust, scale, oxides, and welding residues.
Common acids include hydrochloric acid, sulfuric acid, and nitric acid (depending on the metal).
3. Conversion Coatings
Chemically react with the metal surface to create a protective layer.
Improve paint or powder-coating adhesion and corrosion resistance.
* Examples:
Iron phosphate
Zinc phosphate.
4. Chromate conversion coatings
Zirconium-based coatings
Titanium-based coatings
Passivation Chemicals
Enhance corrosion resistance by forming a protective oxide layer.
Commonly used on stainless steel and aluminum.
5. Rinse Additives and Sealers
Applied after conversion coating.
Improve coating performance and durability.
