Influence of production parameters on surface energy of tinplate

Abstract

The surface energies of commercially produced tinplate samples have been characterised. The surface energies were determined using contact angle measurements by both a single liquid analysis and a multiliquid analysis using mixtures of water and diacetone alcohol. The single liquid method should be treated with caution as the results are significantly affected by choice of liquid. The multifluid methods are more accurate and reliable, and the optimum methodology for surface energy measurements was developed. The surface energies of the tinplate substrates were in the range of 30 to 35 mJ m⁻², about one third of which was polar in nature. The substrate variables assessed included levels of lubricating oil, chromium passivation, tin, iron–tin alloy and tin oxide as well as surface roughness. A multiparameter analysis showed that the levels of lubricating oil and tin oxide were most significant in determining the surface energy.