Effect of Additives on the Dispersion and Electrophoretic Deposition of Highly Diluted Enamel Suspensions

This work examines the rheological behaviour of aqueous highly diluted suspensions (1 mass-%) to identify additives that may improve the application of vitreous enamel coatings by electrophoretic deposition (EPD). Slurries for EPD were prepared by ball milling frit glass in water with suspending agents. The effect of different additives in the solids concentration range from 0.2 to 2.0 mass-% on the rheological properties of coating solutions was investigated using rotational rheometry and zeta potential measurements. Different sedimentation times were observed for the tested dispersant, binder and coagulator additives. Densicer, an organic-inorganic mix additive, showed the best properties in terms of suspension stability. The high zeta potential measured with this product confirms its potential suitability as a suspension additive for vitreous enamel coatings applied by EPD.