Sheet metal surface treatment
After the workpiece is bent, the riveting and other processes are completed, the surface treatment is carried out, and the treatment of different sheet surfaces is different.
Cold rolled sheet:
After the cold-rolled sheet is processed, the surface plating is generally performed, and after the electroplating, the spraying treatment is not performed, and the phosphating treatment is performed, and the phosphating treatment is performed after the phosphating treatment. The plated surface is cleaned, degreased, and then sprayed.
Stainless steel plate:
(The mirror panel, the fog panel, the drawing board) can be drawn before the bending, without spraying, if it needs to be sprayed, it should be roughened; the aluminum plate is generally treated with oxidation, and different oxidation bottoms are selected according to the different colors of the spraying. color,
Commonly used are black and natural oxidation; aluminum plates need to be sprayed for chromate oxidation treatment. The surface pretreatment can make the cleaning surface significantly improve the adhesion of the coating film and double the corrosion resistance of the coating film. The cleaning process first cleans the workpiece, first hangs the workpiece on the assembly line, first through the cleaning solution (alloy de-oil powder), then into the clean water, then through the spray zone, then through the drying zone, and finally the workpiece from the assembly line Take it down.
After the surface is pre-treated, it enters the spraying process, and the teeth or part of the conductive holes need to be protected when the workpiece is required to be assembled after spraying.
The dental hole can be found into a soft glue stick or screwed into the screw. If the conductive protection is required, it should be attached with high-temperature tape, and the large-scale positioning tool should be used for positioning protection, so that it will not be sprayed into the workpiece when spraying, and can be seen on the outer surface of the workpiece. The nut (flange) hole is protected by screws to prevent the workpiece nut (flanging) hole from being returned after spraying.
Some large-volume workpieces also use tooling protection;
When the workpiece is not assembled and sprayed, the area that does not need to be sprayed is covered with high-temperature resistant tape and paper. Some exposed nut holes are protected by screws or high-temperature rubber. If the workpiece is sprayed on both sides, the nut (stud) hole is protected in the same way; the small workpiece is sprayed with the lead wire or the paper clip and the like; some workpieces have high surface requirements, and the workpiece is grounded before spraying; some workpieces are grounded. The symbol is protected by a special high temperature sticker.
When spraying, the workpiece is first hung on the assembly line, and the dust on the surface is blown off with a gas pipe. Into the spraying area, spray, after the spraying, enter the drying area along the assembly line, and finally remove the sprayed workpiece from the assembly line.
There are also two types of manual spraying and automatic spraying, so the tooling used is different.