The outer shell of the water heater is usually made of cold-rolled steel or galvanized steel, and after spraying, it is required to have a perfect appearance. However, during the forming process, stretch cracks and surface damages are the most common problems.
Details and Difficulties:
During the forming of the cylindrical shell, the stretch area is the most prone to fine cracks;
If the rollers are not finely polished, the spray coating is easily scratched;
If the edge burrs are not properly handled after forming, it will cause "powder adhesion" during spraying or paint peeling in the later stage.
Solution:
Use polishing rollers + surface hardening coating to reduce the friction of the sheet;
Add a pre-bending process in the high-stress area to reduce the one-time deformation of stretch;
After forming, configure a deburring unit to ensure the smoothness of the edges.
What customers really care about is not the production capacity figures, but whether the spray coating can maintain its integrity after forming, which directly affects the appearance quality and lifespan reputation of the product in the market.