Die Assembly And Method Of Extruding Cellular Ceramic Substrates With A Skin

摘要

An extrusion apparatus including a die and a mask are provided such that no slots feed directly into the longitudinal skin forming gap between the mask and the die. In a method of forming a die adapted to improve skin uniformity of extruded cellular ceramic substrates a slotted block of die material is provided including central slots adapted to form a cellular matrix of the substrate and peripheral slots located outwardly of the central slots designed to be covered by a skin former mask and adapted to extrude peripheral batch material. An arcuate skin former is cut corresponding to a target shrinkage so as to intersect the slotted block such that skin flow from tangent slots at 90 degree positions of the die is limited to the peripheral batch material.

主权项

1. A porous ceramic honeycomb body, comprising:
a honeycomb structure comprising perpendicularly intersecting porous ceramic walls; and a coextruded skin surrounding and directly adjacent to the honeycomb structure, the skin comprising first portions of uniform thickness t with each other at the 90 degree positions of the honeycomb structure and second positions of a thickness greater than the uniform thickness t off the 90 degree positions of the honeycomb structure.