Abstract: Apparatus and a method for selectively vapor-coating an extrusion die to extrude honeycombs with desired distributions of web thicknesses, wherein at least one perforated impedance or preferential coating plate with a desired pattern of holes is positioned adjacent to, but spaced apart from, a face of the extrusion die to be coated, whereby a coating gas passed through the coating plate and into the die imparts a desired coating distribution to the extrusion die slots that is effective to closely control the web thickness distribution in honeycombs extruded therefrom.

Abstract: A method is provided for manufacturing a thin-walled honeycomb ceramic substrate by extruding a plasticized ceramic batch material through a filter screen having wedge shaped filter wires to remove foreign particulate and agglomerated batch material. The filter wires are supported by a set of support wires attached substantially perpendicular to the filter wires. The support wires are may also be advantageously wedge shaped. The filter screen of the present invention may have a wear resistant layer at the surface of the screen, typically a boride or a nitride. The wear resistant coating may also be a nickel-based coating.

Abstract: Apparatus and a method for selectively vapor-coating an extrusion die to extrude honeycombs with desired distributions of web thicknesses, wherein at least one perforated impedance or preferential coating plate with a desired pattern of holes is positioned adjacent to, but spaced apart from, a face of the extrusion die to be coated, whereby a coating gas passed through the coating plate and into the die imparts a desired coating distribution to the extrusion die slots that is effective to closely control the web thickness distribution in honeycombs extruded therefrom.

Abstract: A method is provided for manufacturing a thin-walled honeycomb ceramic substrate by extruding a plasticized ceramic batch material through a filter screen having wedge shaped filter wires to remove foreign particulate and agglomerated batch material. The filter wires are supported by a set of support wires attached substantially perpendicular to the filter wires. The support wires are may also be advantageously wedge shaped. The filter screen of the present invention may have a wear resistant layer at the surface of the screen, typically a boride or a nitride. The wear resistant coating may also be a nickel-based coating.

Abstract: A honeycomb extrusion die comprising a die body incorporating an inlet face, a discharge face opposite the inlet face, a plurality of feedholes extending from the inlet face into the body, and an array of intersecting discharge slots extending into the body from the discharge face and interconnecting with the feed holes, the intersecting discharge slots being formed by the side surfaces of a plurality of pins bounded by the slots and extending into the die body from the discharge face, wherein a plurality of the pins include one or more multi-textured side surfaces, each side surface including at least two surface regions differing in surface finish from each other.

Abstract: A honeycomb extrusion die comprising a die body incorporating an inlet face, a discharge face opposite the inlet face, a plurality of feedholes extending from the inlet face into the body, and an intersecting array of discharge slots extending into the body from the discharge face to connect with the feed holes, the intersecting array of discharge slots being formed by the side surfaces of a plurality of pins bounded by the slots and extending into the die body from the discharge face, wherein at least some of the side surfaces of the pins incorporate at least one geometrically designed flow-modifying surface discontinuity.