Detailed Process

General Description:

Degreasing: This is basically a metal cleaning process where removal of grease, oil, lubricants, oxide films, heat treatment scales, etc. is undertaken before protective coating.

Rinsing: After degreasing a rinsing process is carried out to completely wash out the degreasing chemical from the metallic surface.

De-Rusting: This process is carried out to remove heavy rust and soil in the tank using mixed acid at room temperature for about 10-15 minutes. This procedure is capable of removing the traces of rust. After this process another round of rinsing is done

Activation: After rinsing the surface of the sheet metal, it is activated with proper Zn & Mn phosphate coating at ambient temperature.

Phosphating: It is a process that produces a smooth, compact, uniform zinc-nickel phosphate coating. Conducted at room temperature, the dip duration is around 20 minutes. After this process another round of rinsing is done.

Passivation: In order to obtain maximum corrosion resistance over phosphate coating, it is necessary to apply a post treatment in order to seal the pores. A chromate rinse is carried out at room temperature to facilitate this effect

Water Drying: Components are dried in a hot air chamber. The metal is powder painted within 24 hours of the final process

This surface treatment process is being adopted for all the sheet metal components made up of sheet thickness up to 3mm. For components above 3mm or ISMC channels shot blasting process is being used for surface cleaning