A honeycomb body having intersecting porous walls and repeating structural units. Each repeating structural unit has a plurality of inlet channels and outlet channels that extend parallel to each other in an axial direction from an inlet face to an outlet face. Each of the repeating structural units has 2.0<I/O<3.0, wherein I/O is a ratio of a number of inlet channels to a number of the outlet channels, each of the inlet and outlet channels have a same cross-sectional size and shape, and each inlet channel of a particular repeating structural unit directly abuts an outlet channel of the particular repeating structural unit or an outlet channel of an adjacent repeating structural unit. Particulate filters including the honeycomb body, honeycomb extrusion dies, and methods of capturing soot in the honeycomb body are provided, as are other aspects.

A substrate for an exhaust gas treatment unit, particularly for an exhaust system of an internal combustion engine, includes a substrate body (18) elongated in the substrate longitudinal direction (S). The substrate body (18) is flattened in a flattening direction (A) essentially at right angles to the substrate longitudinal direction (S). A plurality of cells (24), which extend essentially in the substrate longitudinal direction (S) and provide flow ducts, are formed in the substrate body (18). The cells (24) are defined by cell walls (20, 22), which extend essentially in the substrate longitudinal direction (S). The cell walls (20, 22) are disposed at an angle in relation to the flattening direction (A).

The plugged honeycomb structure includes a plurality of honeycomb segments, a bonding layer, and plugging portions which plug open ends of cells of each honeycomb segment, and in the honeycomb segment, at least two types of cells having different sectional shapes are formed to constitute predetermined repeated arrangement patterns, and a ratio of a value R2s obtained by dividing an average sectional area S2.sub.in of inflow cells by an average sectional area S2.sub.out of outflow cells in a partial rim circumferential wall cell region is in a range of 1.7 times or more and 2.0 times or less to a value R1s obtained by dividing an average sectional area S1.sub.in of the inflow cells by an average sectional area S1.sub.out of the outflow cells in a whole rim partition wall cell region.

A plugged honeycomb structure includes: a honeycomb substrate and a plugging portion, and is configured to trap particulate matter included in fluid flowing from an inflow side end face to an outflow side end face. The partition wall includes, as raw materials, particulates of a base material and a binder and having a melting point lower than that of the base material, the base material has a particle diameter in a range of 5 m to 60 m, a mass ratio of the binder to a total mass of the raw material of the base material and the binder is in a range of 22 mass % to 45 mass %, and the cells include round cells as a part, the round cells being defined by a circular-arc partition wall having a circular-arc shape that is at least a part of the partition wall to have a circular shape or the like.

A honeycomb structure includes a pillar-shaped honeycomb structure body having porous partition walls, wherein the partition walls have projecting portions, the sectional area SA and the sectional area SB satisfy a relation of Formula (1) mentioned below, the number NA of the projecting portions and the number NB of the projecting portions satisfy a relation of Formula (2) mentioned below, Formula (1): <(the sectional area SA/the sectional area SB)<3, and Formula (2): 0(the number NB of the projecting portions/the number NA of the projecting portions)<1.

A honeycomb structure includes a pillar-shaped honeycomb structure body having porous partition walls, wherein the partition walls have projecting portions, the projecting portions include specific projecting portions in which side surfaces have a divergent shape inclined at an inclination angle of 40 to 70, a relation of 0.04H/A0.40 is satisfied, a relation of 0.04H.sub.1/A0.38 is satisfied, the height H of the specific projecting portion and the height H.sub.1 of the hem satisfy a relation of H.sub.1<H, and a ratio of a total number of the specific projecting portions is 2.5% or more.

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.

A honeycomb structure includes a pillar-shaped honeycomb structure body having porous partition walls surrounding a plurality of cells which extend from a first to a second end face and which form flow channels of a fluid, and a circumferential wall enclosing the partition walls, wherein, specific cell of the cells is provided with a pair of projection which projects into the cell from the partition wall, the projection projects, in at least a pair of opposed partition walls among the partition walls constituting the cell, into the cell from a first and a second side, and which is provided continuously in a direction the cell extends, and in the case where the width of a top part of the projection is denoted by W1, and the width of a bottom part of the projection is denoted by W2, W1>W2 holds, and W2/W1 is 0.5 to 0.9.

A honeycomb structure includes a pillar-shaped honeycomb structure body having porous partition walls, wherein the partition walls have projecting portions, a shape of each cell is polygonal, in the polygonal cell, the projecting portions are disposed on two sides extending from a corner of the cell, respectively, the projecting portions are non-uniformly arranged, a relation of Formula (1) is satisfied, and a ratio of a total number of the corners is 2.5% or more: Formula (1): 1/(N+1)<A/L.

A honeycomb filter includes a plugged honeycomb structure body which has cell rows arranged along one direction in a cross section of the honeycomb structure body and including a first cell row constituted of at least one of an inflow cell and an outflow cell, and a through-cell, and a second cell row including no through-cells. A width P1 (mm) of the first cell row, a width P2 (mm) of the second cell and a curvature radius R of a curved shape of corner portions of a polygonal shape of each cell satisfy relations of Equations (1) and (2) below: Equation (1): 2100(P1/P2100)50, and Equation (2): 0.4(R/1000)/((P1+P2)/2)10020.