The national standard GB1727-79 stipulates six kinds of substrates and four methods of plate making, ISO1514 stipulates four kinds of substrates and the pretreatment methods of various substrates before painting, and does not specify the coating method. ASTMD823-53(1970) stipulates four methods for preparing uniform coating film:
①Automatic paint spraying machine
②Automatic Dip Coater
③Coating film automatic scraper
④ Coating machine (motor-driven) scraper.
Among them, the deviation between the film thickness of ① method and the average film thickness shall not be greater than 1.3 microns; ② method is 3 microns. Whether these methods are feasible has yet to be verified.
