Development of Enamel Coatings in Accordance with Recent Regulations of Food Contact Materials

Abstract

The holding ability of enamel on substrate can be provided by different mechanisms such as chemical bonding. Chemical bonding can be achieved by the diffusion of FeO from the substrate to the enamel, and the diffusion of oxides such as NiO and CoO from enamel to the substrate. In this study, we used frit containing NiO and CoO in enamel according to the recent regulations of food contact materials in order to investigate the effects of these metal oxides on the holding ability of enamel. Firing temperature was kept stable at 830 °C during the experiments, and firing times were 2 and 5 min, so we also observed the effect of firing time at stable temperature. After the trials, migration tests and ICP MS analysis were performed to determine the amount of the Ni and Co which can migrate to food from the enamel. Moreover, impact tests were carried out to determine the holding abilities of enamel in terms of firing time.