Wet Paint Hiding: Measurement Methods and Influential Factors

摘要

The opacity of a coating while wet is an important application property to determine both coverage and quality. While opacity measurements of a dry coating are easily measured via quantitative tests, the hiding of a wet coating is typically measured qualitatively via visual ratings. We will compare the methods for determining wet hiding such as the contrast ratio and scattering, as determined in the laboratory. We will provide comparisons between the various methods for determining wet hiding in the laboratory with visual ratings, which will show that at least a 20 and often 40 lb/100 gal difference in TiO_2 level is needed to see a visual difference for roller applied paints depending on the formulation used. We will also present data showing the most significant factors that affect wet hiding, including titanium dioxide level, binder choice, and dispersion quality.