By separating the matrix from the agglomerate it was possible to determine
the nature of agglomerate breakdown during extrusion within a known geometr
y. Previous attempts at observing agglomerate breakdown have been unsuccess
ful at relating the properties of the paste to the properties of the agglom
erate due to the indistinguishability of the paste a nd the agglomerates. B
y using well-characterized materials, it was found that the breakdown proba
bilities of the agglomerates during extrusion were independent of the posit
ion of the agglomerate. This indicated that as the shear strain rate was kn
own to be highly position dependent, the agglomerate breakdown was shear st
rain rate independent. Following breakdown, the distributive mixing was obs
erved to be position dependent. (C) 1998 Kluwer Academic Publishers.