Today we’re going to try to answer the question that many people probably have about pre-treating the surface of parts before the painting process. But to answer this question, we first need to understand what pre-treatment processes are and how they act on the surface of the part.

Pre-treatment can consist of stages of degreasing, phosphating or the use of nano ceramics, in some cases the use of a stripper and passivator.

Degreasing: Degreasing is the first stage of a pre-treatment. Good degreasers clean parts, remove dirt and help prevent the part from becoming contaminated again. This stage is heated and requires a heat source.

Phosphating and nanoceramics: Phosphating and nanoceramics act on the roughness of the parts, filling in the gaps in the surface, preventing air molecules from lodging and preventing the surface from oxidizing. This stage is also very important as it helps to anchor the paint to the surface of the part.

Pickling: undoubtedly the most aggressive stage of a pre-treatment, pickling products are used to remove oxidation or mill scale still present on the part. The time the part is exposed to this type of product must be well dimensioned so that the part does not suffer too great an attack. After this stage, it is necessary to use a passivator to neutralize it.

Rinsing: The rinsing process is the most common after every other process. No chemicals are used at this stage, only the water that will rinse the garment after each process. This can be mains water or deionized water.

To understand which of these stages and the time taken for each process, the main factor that must be taken into account is the purpose of the final piece, what its role will be and the environment in which it will be displayed. An analysis of samples can also be carried out, together with the company that will supply the products needed to treat the piece.

The type of equipment used in this process is also very important. Spray pretreatment systems are used on continuous lines, where the products are sprayed onto the part. Or immersion systems, where the parts move on skids, ideal for large production quantities and more complex geometries.