Environmental and Quality Analysis of Aqueous Tape Casting

Bok, 2011

Ceramic tapes are traditionally produced by tape casting using organic solvents. The use of organic solvents has been questioned due to health, environmental and fire hazard risks. The use of water-based tape casting can reduce these problems. This study contains an environmental assessment of ceramic tapes in a life cycle perspective. Two tape casting techniques, using different solvents during the tape casting, are analyzed from cradle to grave, ie, from raw material production, manufacturing, application and recycling. The functional unit was defined as tape with 1000 gram of alumina content. Tape casting with water based solvent was compared to tape casting with hydrocarbon based solvent. In principal, only differing processes were examined. There are also quality issues associated with water based tape casting: the drying is slower and can cause cracking, air bubbles can be entrapped, and in some cases there can be problems with wetting. These problems can be handled by controlling the colloidal and rheological properties and using a system with high solids loading. In conclusion the results show that water based tape casting gives tapes of high quality and that a lower environmental impact is possible compared to solvent based tape casting. It is further shown that the sintering of the green tape, which follows the tape casting, is probably the process with most climate impact in the life cycle of a ceramic tape.