Sheet metal parts spray painting pre-treatment process

Sheet metal parts spray painting pre-treatment process.

1. Degreasing

There is often oil stain on the surface of sheet metal parts, which will affect the painting effect if not treated. Solvents and alkaline cleaning agents can be used for degreasing. When treating with solvents, choose appropriate cleaning agents, such as alcohols, ketones, chlorinated hydrocarbons, aromatic hydrocarbons, etc. Choose different solvents according to the type of oil stain. When cleaning with alkaline cleaning agents, pay attention to the concentration and temperature of the cleaning agent.

2. Sandblasting

Sandblasting can remove impurities such as oxide scale and rust on the surface, increase surface roughness, and thereby improve spray adhesion. Pay attention to pressure, nozzle size and distance when sandblasting.

3. Rust removal

When there is rust on the surface of sheet metal parts, rust removal treatment is required. Rust removal methods include mechanical rust removal and chemical rust removal. Mechanical rust removal includes grinding and scraping, and chemical rust removal includes pickling, phosphating, etc.

4. Filling

Some sheet metal parts have uneven surfaces or scratches that require filling. The filling material can be a primer material or a special filling material. When filling, pay attention to the filling thickness and filling method.

5. Smooth

Smoothing is to reshape the surface of sheet metal parts to make the surface smooth and flat. The smoothing process is completed together with the processing steps of filling, sanding and scraping.