Phenomenological study and modelling of wick debinding

Wick debinding employs capillary suction (via a surrounding wicking powder) to remove the liquid binder phase from powder injection moulded parts (known as a compact). Experimental measurements of binder distribution within the compact during debinding highlight flaws in previous wick debinding models. The spatially uniform distribution of binder observed consistently during debinding indicates that it is removed in order of pore size regardless of location in the compact. A model is proposed which gives good agreement with 1-D experimental data of binder distribution. Key parameters of the model are the permeability of the wicking powder and the relationship between the capillary pressure, saturation and relative permeability of the compact.