Method 1 of Metal Surface Treatment: Surface treatment before painting
In order to remove the various objects (such as oil stains, rust, dust, old paint film, etc.) that attached to the surface of the workpiece, provide a good substrate for coating requirements, ensure the coating film has good corrosion resistance, decorative properties and some special features . It must be pre-treated on the surface of the object before painting. The work done by this process is collectively referred as the pre-coating (surface) treatment or (surface) pretreatment.
Method 2 of Metal Surface Treatment: Manual treatment
Such as scrapers, wire brushes or grinding wheels. The rust and scale on the surface of the workpiece can be removed by hand, but the manual treatment is labor intensive, the production efficiency is low, the quality is poor, and the cleaning is not thorough.
Method 3 of Metal Surface Treatment: Chemical treatment
It mainly uses an acidic or alkaline solution to chemically react with oxides and oil stains on the surface of the workpiece, to dissolve it in an acidic or alkaline solution to remove rust scale and oil stain on the surface of the workpiece, then use nylon brush roller or 304# stainless steel wire (the wire brush roller made of acid and alkali solution can be cleaned to achieve the purpose. The chemical treatment is suitable for cleaning the thin plate parts, but the disadvantage is: if the time is not properly controlled, even if the corrosion inhibitor is added, It can also cause over-etching of steel. For more complicated structural parts and porous parts, after acid pickling, the residual acid immersed in the gap or hole is difficult to be completely removed. If it is not treated properly, will become a hidden danger of corrosion on the workpiece, and the chemicals are volatile, the cost is high, and the chemical discharge after treatment is difficult. If not treated properly, it will cause serious pollution to the environment. With the improvement of people's environmental awareness, this treatment method is being replaced by mechanical treatment.