Hungthai Metal is a steel manufacturing in china. In order to obtain prepainted galvanized steel coil and prepainted galvalume steel coil with good color coating performance, we will pre-process the substrate.
Hungthai Metal adopts unique substrate pretreatment technology to make the surface of galvanized steel coil and galvalume steel coil adhere to a layer of phosphate conversion coating, which greatly improves the life and weather resistance of color coated steel coil.
The phosphate conversion coating technology of Hungthai Metal is to put galvanized steel coil and galvalume steel coil into a solution containing phosphophyllite for chemical treatment. Phosphate treatment, referred to as phosphating.
The phosphating of Hungthai Metal adopts the unique mixed solution technology of hopeite and phosphophyllite, which greatly improves the life of galvanized material and galvalume steel coil. To ensure that the color coating of color coated steel coil is not easy to peel off, so that customers can obtain high quality PPGI and PPGL.
The reason why the phosphating film can improve the color coated steel coil is that the phosphating film is a porous structure, so it has a good absorption of oil, grease, soap and other properties, and improves the protection of galvanized material and galvalume steel coil. Phosphate film greatly improves the adsorption of various organic films, so it also greatly improves the corrosion resistance of paints and other organic films.
When the metal is phosphated, the corrosion of the damaged area is only local. This is because the metal surface is firmly adsorbed on the metal surface, the non-conductor — the phosphating film insulation. The phosphating film also prevents the electrolyte from being in the horizontal direction. Diffusion, therefore metal corrosion under the organic film is suppressed, greatly improving the lifetime of galvanized steel coil and galvalume steel coil exposed to air.
After phosphating, three steps of water washing, passivation and drying are also required. These processes also affect the quality of the phosphating film.
The most important thing here is the passivation treatment of the galvanized material and galvalume steel coil, because the phosphating film is microscopically porous and uneven, and passivation has the effect of further dissolving and sealing the phosphating film, reducing its porosity and corrosion resistance. Enhanced, the effect is remarkable. Especially when the phosphating film is thin, its porosity is large, the corrosion resistance of the phosphating film itself is limited, and some are even rapidly oxidized and rusted during the drying process. A passivation treatment is performed after phosphating, so that the metal in the pores of the phosphating film can form a passivation layer, so that the pores of the phosphating film can be closed and filled.
After passivation treatment, the phosphating film can also dissolve the loose layer on the phosphating surface and various water-soluble residues contained in it, so that the phosphating film will not be rapidly corroded and rusted in the air, thus improving the phosphating The rust resistance and corrosion resistance of the film itself.
As a responsible ppgi coil exporter China and PPGI manufacturer China, Hungthai Metal keeps innovating to ensure the quality of prepainted galvanized steel coil and PPGL, giving customers good prices and good quality, and looking forward to cooperating with you.