Electrolytic tinplate sheet varnish is a coating that is applied to the surface of tinplate printed products that have completed all color registration or directly to metal. Correct selection and coating of varnish can make the coating film of the printing surface have certain flexibility and chemical resistance, increase the hardness of the coating film, protect the surface of the printed matter, and also make the coated tinplate surface bright and beautiful. The main quality indexes of varnishes for printing tinplate that need to be considered in printing are as follows.
(1) The coating of lacquered tinplate is uniform and free of appearance defects such as pinholes, craters, fish eyes, and missing coatings.
(2) The coating on electrolytic tinplate sheet is dense, has good adhesion, and has good mechanical processing properties.
(3) The coatings of cans and beverage packaging containers also have good cooking resistance, and should not crack, fall off or change color under high temperature conditions.
(4) The coating should have a certain hardness, and it should not be scratched during machining, storage, transportation and sales, so as not to affect the appearance of the coated tinplate product.
(5) The coating on electrolytic tinplate sheet has good gloss,the lacquered tinplate can protect and set off the graphics.
