Honeycomb extrusion apparatus and methods

A method of co-extruding a central portion of a honeycomb body with an integral skin, the method comprising the steps of:

• (I) providing a die body including an array of pins that are spaced apart to define an extrusion face with a honeycomb network of discharge slots extending along an extrusion axis of the die body, the die body further including an outer peripheral surface facing away from the extrusion axis and circumscribing the extrusion face, wherein the honeycomb network of discharge slots at least partially defines a first resistance to a skin batch flow at a first location of the outer peripheral surface, the honeycomb network of discharge slots at least partially defines a second resistance to the skin batch flow at a second location of the outer peripheral surface that is spaced from the first location in a direction about the extrusion axis, wherein the first resistance is less than the second resistance;
• (II) providing a mask including an inner peripheral surface;
• (III) mounting the mask to the die body such that the inner peripheral surface at least partially circumscribes the outer peripheral surface of the die body to define a peripheral gap between the inner peripheral surface and the outer peripheral surface that circumscribes the array of pins, and wherein the peripheral gap includes a first extrusion cross section associated with the first location of the outer peripheral surface, and the peripheral gap includes a second extrusion cross section associated with the second location of the outer peripheral surface, wherein an overall flow area of the first extrusion cross section is less than an overall flow area of the second extrusion cross section;
• and
• (IV) extruding a quantity of batch material through an overall peripheral flow area of the peripheral gap while extruding another quantity of the batch material through the honeycomb network of discharge slots such that a central portion of the honeycomb body is co-extruded with an integral skin defining an outer periphery of the honeycomb body.