A METHOD FOR CALCULATING THE PRESSURE-DROP IN HONEYCOMB DIES

Three ceramic pastes based on alumina with different binder systems we re characterised using physically, based equations and the pressure dr op measured as they passed through an experimental honeycomb die. Usin g an additive approach the pressure drop through the honeycomb die was predicted from the paste parameters derived by the characterisation m ethod and the results compared with the experimentally determined pres sure losses. In simple pastes based on a clay-starch binder system, wh ere their pressure-velocity relationships were near-linear and the die entry velocity dependence was small, the predicted and experimental v alues were in reasonable agreement (+/- 10%) but in more complex syste ms using polymer solution binders the Jit was less accurate (-10 to -4 5%) for the best of the four models evaluated. This was attributed to the divergent flow in the die on passage from the die holes to slots w hich at present cannot be modelled using the method of analysis adopte d. (C) 1996 Elsevier Science Limited.