Characterization of different types of lacquers used in food packaging: porosity, flexibility and IR reflectance spectroscopy tests

UV-cured (ultra violet), water-based and epoxyphenolic lacquers have been characterized as coatings for possible application in vegetable canning industry. These lacquers were applied to three different types of tinplates and tin free steel (TFS). The behaviour of lacquers was monitored applying porosity, flexibility and infrared (IR) reflectance spectroscopy tests. With IR reflectance spectroscopy test, we were able to determine the composition of lacquers. Using porosity and flexibility tests, performed by electrochemical methods, it was possible to characterize the best lacquer for food canning. In this work the variables involved in lacquering, e.g. the weight of coating and the degree of polymerization of lacquers were also taken into account.