Abstract: A skin-forming die includes an inlet face; an outlet face; one or more slots, each of the one or more slots comprising one or more slot inlets extending between the one or more slot inlets and the outlet face; a plurality of feedholes extending between the inlet face and the one or more slot inlets; and a central opening configured to receive a matrix die. Extrusion die apparatus and methods of manufacturing honeycomb bodies are also disclosed.

Abstract: A honeycomb extrusion die assembly (10) comprising a honeycomb extrusion die (701) and a forming plate (800) to block batch flow to at least a portion of a skin forming region. The honeycomb extrusion die (701) comprising a step cut discharge surface (758, 760) in the skin forming region and at least some slots (722) each with a divot (312) spaced toward a discharge surface (710) from a feedhole-slot intersection and a wide portion at the discharge surface (710) extending into the die body to the divot (312) to strengthen a peripheral region of a honeycomb extrudate in a reinforcement region, and a bulk nominal section corresponding to a bulk region of the honeycomb body.

Abstract: A honeycomb extrusion die assembly (10) comprising a honeycomb extrusion die (701) and a forming plate (800) to block batch flow to at least a portion of a skin forming region. The honeycomb extrusion die (701) comprising a step cut discharge surface (758, 760) in the skin forming region and at least some slots (722) each with a divot (312) spaced toward a discharge surface (710) from a feedhole-slot intersection and a wide portion at the discharge surface (710) extending into the die body to the divot (312) to strengthen a peripheral region of a honeycomb extrudate in a reinforcement region, and a bulk nominal section corresponding to a bulk region of the honeycomb body.

Abstract: Methods of firing a cordierite green body to form a fired cordierite body. The green body comprises cordierite-forming raw materials and organic material, the body having a core portion and a skin portion. The green body is pre-heated to a pre-heat temperature that is less than a thermal decomposition temperature of the organic material. The green body is maintained at the pre-heat temperature for a period of time sufficient to minimize a temperature differential between the core portion and the skin portion. The green body is heated to a low firing temperature in a firing atmosphere sufficient to reduce a content of the organic material and to substantially remove chemically bound water from hydrous alumina. The green body is heated to a high firing temperature in a firing atmosphere sufficient to reduce the content of the organic material prior to a substantial removal of chemically bound water from clay.

Abstract: The invention is directed to a method for managing pore size distribution in honeycomb substrates by using two or more pore forming agents in the batch ingredients. In particular, the invention is particularly useful in managing pore size distribution in cordierite and aluminum titanate honeycomb substrates in the face of particle size variations in the pore forming agents and other materials used to make such substrates.

Abstract: Methods of firing a cordierite green body to form a fired cordierite body. The green body comprises cordierite-forming raw materials and organic material, the body having a core portion and a skin portion. The green body is pre-heated to a pre-heat temperature that is less than a thermal decomposition temperature of the organic material. The green body is maintained at the pre-heat temperature for a period of time sufficient to minimize a temperature differential between the core portion and the skin portion. The green body is heated to a low firing temperature in a firing atmosphere sufficient to reduce a content of the organic material and to substantially remove chemically bound water from hydrous alumina. The green body is heated to a high firing temperature in a firing atmosphere sufficient to reduce the content of the organic material prior to a substantial removal of chemically bound water from clay.

Abstract: The invention is directed to a method for managing pore size distribution in honeycomb substrates by using two or more pore forming agents in the batch ingredients. In particular, the invention is particularly useful in managing pore size distribution in cordierite and aluminum titanate honeycomb substrates in the face of particle size variations in the pore forming agents and other materials used to make such substrates.

Abstract: A method of removing graphite from a core region of a cordierite-forming green body and a method of firing a cordierite-forming green body to form a fired cordierite body. A dried cordierite-forming green body containing graphite is first heated so that the core region is at a first temperature in a range from about 950° C. up to about 1100° C. The green body is then either held at the first temperature or heated to a second temperature in a range from about 1050° C. up to about 1160° C.; in either case resulting in removal of a majority of graphite from the core region. The green body may then be heated to a third temperature in a range from about 1300° C. up to about 1350° C. at a second predetermined heating rate to remove any residual graphite from the core region and then heated to a temperature of at least 1390° C. to form the fired cordierite body.