OPTIMIZATION OF DISPERSION AND VISCOSITY OF A CERAMIC LET PRINTING INK

Different amounts (0.5-10.0 wt%) of an oligomeric dispersant were adde d to a ceramic ink containing 30 vol% of zirconia in butyl acetate, Th e sediment packing densities of the resulting suspensions were measure d. The viscosities of the suspensions were determined using a syringe that was adapted as a capillary viscometer suitable for the measuremen t of the low viscosities encountered (up to 400 mPa . s). The highest sediment-packing density coincided with the lowest viscosity and occur red when 1-2 wt% of dispersant, based on the ceramic, was added. Inves tigation of the supernatant of the suspensions by thermogravimetric an alysis indicated that this amount corresponded to the highest level of adsorption of the dispersant on the ceramic. The sediment from this s uspension yielded a high density on subsequent sintering.