Chemical surface pre-treatment
A key technological step for maximum adhesion and long-term coating protection.
The final quality of the cured powder coating largely depends on correct chemical surface pre-treatment even before the paint is applied.
Chemical surface preparation ensures the removal of grease, oils, and micro-contaminants, while also creating a conversion layer that significantly increases powder adhesion and improves anti-corrosion protection.
This is a technologically demanding process that requires precise control of every step.
Classification by material
Pre-treatment of iron and steel – phosphating
For steel and iron, we use a phosphating process. This creates an intermediate layer approximately 2–5 μm thick, which:
• increases powder coating adhesion
• improves corrosion resistance
• stabilizes the surface before the final finish
We use iron phosphate, which can be applied to iron, steel, aluminium, and galvanized surfaces.
Pre-treatment of aluminium – titanium conversion coating
For aluminium parts, a titanium conversion coating process is used. This procedure creates a conversion layer optimized for aluminium materials and ensures uniform coating adhesion.
Each material requires an individual technological approach to ensure long-term stability of the surface finish.
How does the chemical process work?
Chemical pre-treatment consists of several consecutive steps:
• immersion in a degreasing solution
• rinse in demineralized water
• immersion in a conversion (phosphating or titanium conversion) solution
• passivation
• final rinses
Each immersion has a precisely defined process time and solution temperature. The solutions are monitored and checked daily to ensure stable process quality and repeatable results.
Why is chemical pre-treatment crucial?
Properly performed chemical pre-treatment:
• significantly extends coating service life
• minimizes the risk of underfilm corrosion
• increases resistance to moisture and aggressive environments
• ensures uniform powder curing
Without high-quality chemical preparation, even the most advanced powder coating would not achieve the required durability.
