A 5-liter paint can made of tinplate, depending on the characteristics of the contents, usually requires a certain coating on the inner surface of the container to prevent the contents from eroding the tank wall and contents, which is conducive to long-term storage. For confectionery boxes, in order to prevent the processing of curling, the iron is rubbed and rusted, it is also necessary to apply a layer of decorative paint to increase the appearance.
The performance of the paint inside the 5-liter paint can is not only resistant to corrosion, good adhesion, flexibility, non-toxic, odorless, in line with food hygiene and safety requirements, but also needs to be heated in the post-process such as high-frequency resistance welding. Local high temperature heating of the internal coating, and high temperature cooking at 120 ° C after canning without fading and loss of light.
Generally, phenolic resin coating, epoxy-phenolic resin coating, acrylic resin coating and aluminum powder coating are applied, and the inner coating type and coating thickness are generally selected according to the characteristics of the contents. Since the 5-liter paint can product is generally printed first, and then canned, the can is subjected to bending, stretching, welding, flanging, winding, etc., except that the dry film and ink layer are required to have sufficient strength. It is also required to have sufficient adhesion to avoid defects during the forming process