The invention discloses method and apparatus for providing a desired batch
flow through desired regions of an extrusion die for forming honeycomb
structures, and more particularly to the enhancement of batch flow in the
skin-forming region of the die so as to provide a bounding wall of
desired thickness and strength about a honeycomb core. Unlike prior
methods, a recess or trough of desired depth and width is formed in a
desired region of the inlet face of the honeycomb die, which reduces the
pressure required to flow batch material through the die in such region.
Such reduced pressure requirement translates in an increased flow rate in
such region under constant extrusion pressure. Thus by increasing the
flow rate through a honeycomb extrusion die in an outer peripheral region
of flow in this manner, improved skin formation around a honeycomb core
is obtained during the forming process.