EFFECT OF TINPLATE SURFACE PROPERTIES ON PERFORMANCE OF ULTRAVIOLET-CURED INKS AND LACQUERS

摘要

Ultraviolet curing (UVC) of inks and lacquers on tinplate is being practiced by an increasing number of energy-conscious metal decorators. Some find that tinplate given a cathodic dichromate (CDC) treatment is unsuitable for UVC coatings. A study of the problem showed that high-energy (good wetting) CDC-treated surfaces perform well with UVC lacquers. Producing high-energy CDC tinplate surfaces, however, requires rigid control of treatment parameters and, although improved performance of UVC lacquers can be thus achieved, the improvement is frequently compromised by the deleterious effect of the tinplate lubricant. Consistently excellent UVC performance on CDC-treated plate can be assured (regardless of treatment parameters or oil-film weight) by following the CDC treatment with a rinse of 0.5% citric acid. The citric acid rinse process also improves the wetting and adhesion of most conventional lacquers and does not adversely affect the storage stability of the tinplate.