An attempt is made to set up the fundamentals forapplying mathematical process modelling on the basis of rational thermomechanicsto the forming process of oxide ceramic pastes plasticized by thermoplasticbinders. Using a continuum description throughout we start with the localbalance equations known from traditional continuum mechanics and mention thespecial status of the entropy inequality. Looking for a material model as simpleas possible but as complex as needed, constitutive theory is used to deduce asimple fluid model (the generalized Newtonian liquid) with the help ofconstitutive principles, and for the one-dimensional case the Herschel-Bulkleymodel is suggested. In order to make the theory liable to experimentalverification, idealizations are made concerning flow geometry. Boundaryconditions are shortly discussed. Apart from delivering a rational framework forthe modelling of ceramic injection molding, the methodological approach appliedin this paper should be of value also for other widely used forming processes inceramic technology, especially cold extrusion, extrusion at elevated temperatureor hot extrusion.
