Extrusion die for protrusion and/or high cell density ceramic honeycomb structures

An extrusion die for forming honeycomb structures with intersecting cell walls from extrudable material, which comprises

• a die body having an inlet face and an outlet face,
• a plurality of feed holes extending within the body from the inlet face toward the outlet face,
• the feed holes directly communicating only with each of a plurality of transversely crisscrossed primary discharge slots defined by a plurality of primary core members of the body and extending within the body from the outlet face toward the inlet face, with inner end portions of the feed holes communicating longitudinally and transversely in overlapping manner with inner end portions of the primary discharge slots, and
• characterized by the improvement comprising secondary discharge slots extending within the primary core members from the outlet face toward the inlet face and into direct transverse communication with the primary discharge slots, the secondary discharge slots dividing the primary core members into secondary core members defining the secondary discharge slots, said secondary discharge slots not directly communicating with said feed holes and the inner ends of at least some of the secondary discharge slots being provided with enlarged extensions constituting feed reservoirs extending along and communicating with said inner ends.