Application of alginate gelation to aqueous tape casting technology

This work deals with a novel forming process for manufacturing ceramic tapes in an aqueous medium, that combines tape casting and gel-casting technologies. Aqueous tape casting suspensions of Al2O3 are prepared to a solid loading of 57 vol.% (84 wt.%) by adding 15 wt.% of a binder system consisting of acrylic emulsions and a small concentration (less than or equal to0.5 wt.%) of alginate. The as-cast tape is immersed in a CaCl2 solution and the alginate undergoes gelation. This allows releasing of the tape from the carrier film so that no sticking occurs and crack formation is avoided. Sintered densities are similar to97% of theoretical, similar to those obtained by conventional aqueous tape casting. (C) 2002 Elsevier Science Ltd. All rights reserved.