Abstract: Methods of manufacturing honeycomb-structure-forming extrusion dies having a number of slots for use in producing extruded articles having complex honeycomb patterns and extrusion dies for use in the manufacture of extruded honeycomb bodies. The method includes inserting a die insert having a runner and a number of teeth into a slot of an extrusion die such that each of the teeth blocks at least a portion of the slot of the extrusion die. The method further includes separating the runner from the teeth so that the teeth remain within the slot of the extrusion die.

Abstract: An apparatus and method to machine cavities in die blanks having little to no taper. The apparatus includes an electrode tool (200) including intersecting walls coated with electrically insulating coating (258), an erosion face (204) comprising a cross section of the walls exposed through the electrically insulating coating, and a channel formed by the walls to supply electrolyte to the erosion face, the channels defined by interior surfaces of the walls and having an opening formed by edges of the erosion face. The method includes pulsed electrochemical machining a work piece with the electrode tool.

Abstract: Ceramic honeycomb bodies and methods for canning the bodies are disclosed herein. The honeycomb bodies comprise a porous ceramic honeycomb structure. The honeycomb structure comprises a network of cells defined by walls that extend in an axial direction about a longitudinal axis from an inlet end to an outlet end of the honeycomb structure. The honeycomb structure also comprises a portion of cells with protrusions. The portion of cells with protrusions supports a greater concentration of catalyst, as compared to a portion of cells without protrusions. The portion of cells with protrusions is disposed off-center with respect to the longitudinal axis of the honeycomb structure such that the portion of cells with protrusions (and greater concentration of catalyst) corresponds to areas of high exhaust flow through the structure.

Abstract: A particulate filter having a honeycomb structure of a matrix of interconnected porous walls including inlet cells and outlet cells defining a plurality of inlet channels and outlet channels, respectively, wherein at least a portion of the outlet cells are larger than any of the inlet cells, and a cross-sectional shape of at least some of the outlet channels is rectangular. Honeycomb extrusion dies, honeycomb bodies, honeycomb structures, and methods of manufacture are described, as are other aspects.

Abstract: A method to form a laminar integral skin of a honeycomb structure is provided. The method includes extruding a ceramic precursor batch through a die with feedholes in entry side and slots in exit face of the die to form the honeycomb structure. In a region on the periphery of the die configured to form the cell matrix, a series of concentric slots around the matrix in the exit face of the die are configured to feed skin onto the matrix. Ring sections between concentric slots are angled away from the center and a mask is disposed on top of the periphery producing a channel for extruded skin to meet and bond to extruded matrix. Optionally, slots in the skin-forming ring sections enhance knitting between laminar skin layers. The die and honeycomb body having uniform integral skin are also provided.

Abstract: An apparatus and method to machine cavities in die blanks having little to no taper. The apparatus includes an elec trode tool (200) including intersecting walls coated with electrically insulating coating (258), an erosion face (204) comprising a cross section of the walls exposed through the electrically insulating coating, and a channel formed by the walls to supply electrolyte to the erosion face, the channels defined by interior surfaces of the walls and having an opening formed by edges of the erosion face. The method includes pulsed electrochemical machining a work piece with the electrode tool.

Abstract: Methods for making extrusion dies using a LIGA process, a German acronym for lithography (Lithographie), electroplating (Galvanoformung), and molding (Abformung), are described. The resulting extrusion dies can be used, for example, for extrusion of cellular ceramic substrates, precision extrusion of optical fiber or optical fiber precursors, or other applications where profile extrusion requires high dimensional precision and/or has otherwise intricate patterns.

Abstract: A wall-flow honeycomb filter has a monolith body which includes repeating hexagonal unit cells, wherein each hexagonal unit cell has inner cells and outer cells arranged in a hexagonal symmetry, and wherein the inner cells are bordered by the outer cells and the outer cells are of diamond shape.

Abstract: Extruded metal honeycombs are produced by the direct extrusion of a softened bulk metal feedstock through a honey-comb extrusion die comprising a feedhole array for delivering softened metal through a supporting die baseplate to a honeycomb die discharge section, the discharge section comprising an array of intersecting discharge slots that form the walls of an extruded metal honeycomb structure. This process can be optimized by employing a proper pressure gradient for a particular extrudate flow rate, extrudate composition, and wall-drag condition arising from the particular composition of the feedhole wall, as illustrated graphically in FIG. 4.

Abstract: Methods for making extrusion dies using a LIGA process, a German acronym for lithography (Lithographie), electroplating (Galvanoformung), and molding (Abformung), are described. The resulting extrusion dies can be used, for example, for extrusion of cellular ceramic substrates, precision extrusion of optical fiber or optical fiber precursors, or other applications where profile extrusion requires high dimensional precision and/or has otherwise intricate patterns.

Abstract: A radial cell ceramic honeycomb structure is provided that is particularly adapted for use as a catalytic carrier or a particulate filter in an automotive or diesel exhaust system. The honeycomb structure includes a network of interconnected webs having a central axis. The network of webs includes radial webs of varying lengths, only some of which substantially extend the entire radial length of the network, and tangential webs that intersect to define rings of gas-conducting radial cells, and a rounded outer skin that surrounds the cells formed by the interconnected webs. The radial webs extending to the periphery of the network join an inner edge of the outer skin in a substantially orthogonal orientation to reduce thermally generated stresses and to increase strength of the resulting structure. The number of radial webs in the network changes along the radial length at transition zones that are defined by one of the tangential webs such that a desired cell density is achieved across the network.

Abstract: Extruded metal honeycombs are produced by the direct extrusion of a softened bulk metal feedstock through a honey-comb extrusion die comprising a feedhole array for delivering softened metal through a supporting die baseplate to a honeycomb die discharge section, the discharge section comprising an array of intersecting discharge slots that form the walls of an extruded metal honeycomb structure. This process can be optimized by employing a proper pressure gradient for a particular extrudate flow rate, extrudate composition, and wall-drag condition arising from the particular composition of the feedhole wall, as illustrated graphically in FIG. 4.

Abstract: A ceramic wall-flow filter for filtering particulate matter from gases and methods for manufacturing such wall-flow filters are disclosed. The filter includes an array of porous ceramic walls defining a pattern of end-plugged inlet and outlet cells, and heat absorbing elements disposed within at least some of the outlet cells such that a bulk heat capacity of the outlet cells is greater than a bulk capacity of the inlet cells. The heat absorbing elements increase a bulk heat capacity of the filter without substantially interfering with a flow of gas through the porous ceramic walls by allowing thinner walls. According to the method, during the step of extruding or thereafter, heat absorbing elements are formed within at least some of the outlet cells such that a heat capacity of the outlet cells is greater than the inlet cells.

Abstract: A wall-flow honeycomb filter has a monolith body which includes repeating hexagonal unit cells, wherein each hexagonal unit cell has inner cells and outer cells arranged in a hexagonal symmetry, and wherein the inner cells are bordered by the outer cells and the outer cells are of diamond shape.

Abstract: A method for forming honeycomb structures, such as wall-flow honeycomb filters, which utilizes extrusion of multiple material supplies at once. Such methods may be used to form intermittent plugs or other structures in the cell channels during the extrusion process, for example. A die assembly is provided which includes secondary feedholes machined in the pins for intermittently or periodically injecting secondary material (e.g., plug material) into the cell channels of the honeycomb structure while it is being extruded.

Abstract: A radial cell ceramic honeycomb structure is provided that is particularly adapted for use as a catalytic carrier or a particulate filter in an automotive or diesel exhaust system. The honeycomb structure includes a network of interconnected webs having a central axis. The network of webs includes radial webs of varying lengths, only some of which substantially extend the entire radial length of the network, and tangential webs that intersect to define rings of gas-conducting radial cells, and a rounded outer skin that surrounds the cells formed by the interconnected webs. The radial webs extending to the periphery of the network join an inner edge of the outer skin in a substantially orthogonal orientation to reduce thermally generated stresses and to increase strength of the resulting structure. The number of radial webs in the network changes along the radial length at transition zones that are defined by one of the tangential webs such that a desired cell density is achieved across the network.