A plugged honeycomb structure includes a honeycomb structure body, and a plurality of plugging portions, the honeycomb structure body further includes pass-through hole portions each of which is formed in at least a part of a partition wall intersection portion in which the partition walls intersect in one end face and each of which interconnects a pair of cells facing each other at a position corresponding to the partition wall intersection portion to enable pass-through of a fluid, and a value obtained by dividing a diameter of a first virtual inscribed circle inscribed at a position of a minimum hole width of the pass-through hole portion by a diameter of a second virtual inscribed circle inscribed at a position of a minimum plugging width between the plugging portions facing each other is in a range of 0.05 to 0.74.

A plugged honeycomb segment includes a honeycomb segment having a quadrangular prism shape which includes porous partition walls arranged to surround a plurality of cells and an outermost circumferential wall, and a plugging portion, wherein a porosity of the partition walls is 30 to 70%, in a cross section orthogonal to the cell extending direction, an inflow cell surrounded by the partition walls is a hexagon, and an outflow cell is a square, one outflow cell is surrounded by four inflow cells, the cell located at the outermost circumference includes a complete cell and an incomplete cell, and a thickness of the outermost circumferential wall in contact with the incomplete cell (T1), a thickness of the outermost circumferential wall in contact with the complete cell (T2), and a thickness of the partition walls (WT), satisfy 0.200 mm<T1<T2−(½×WT) and T2≤0.700 mm.

An object of the present invention is to provide a honeycomb filter capable of achieving a combination of high collection efficiency and low pressure loss. The honeycomb filter comprises a ceramic honeycomb substrate in which a multitude of cells through which a fluid flows are disposed in parallel in a longitudinal direction and are separated by cell walls, each cell being sealed at an end section at either the fluid inlet side or the fluid outlet side, and a filter layer which, among the surfaces of the cell walls, is formed on the surface of the cell walls of those cells in which the end section at the fluid inlet side is open and the end section at the fluid outlet side is sealed by a sealing material, wherein the thickness of the filter layer increases gradually from the fluid inlet side toward the fluid outlet side.

A particulate trap filter body has asymmetrical channels. The cross-sectional shape of the asymmetrical channel structure includes a combination of hexagonal, square and triangular shapes. The hexagonal channel and the triangular channel act as inlet channel, and the square channel acts as outlet channel. Compared with the traditional symmetrical filter body structure, the inlet channel volume and filter body wall area can be effectively increased by more than 30%, which means that with capturing the same amount of particles, the particle cake layer formed on the wall surface is thinner. The limiting carbon load of the new channel structure is increased by more than 30%, having a very positive effect on reducing the regeneration frequency and prolonging the service life of the trap.

A method and extrusion die 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.

Ceramic honeycomb bodies and methods for then manufacture are provided. The ceramic honeycomb body comprises a bulk density of less than 210 g/L, a geometric surface area (GSA) greater than 93 in.sup.−1 (3.66 mm.sup.−1), a mechanical integrity factor (MIF) greater than 0.28%, and a back pressure factor (BPF) greater than 0.4 mm.sup.2.

A honeycomb structure includes a plurality of prismatic columnar shaped honeycomb segments; a bonding layer bonding side faces of the honeycomb segments; and a circumferential wall disposed to surround a honeycomb segment bonded body having the honeycomb segments arranged in a grid pattern and bonded with the bonding layer, wherein the honeycomb segments has a porous partition wall disposed to surround a plurality of cells, the cells in other than outermost circumference have a hexagonal shape in a section orthogonal to the cell extending direction, the honeycomb segments include first and second honeycomb segment, the second honeycomb segment is different from the first in at least one of: a shape in the section; a size; and an arrangement direction of the cells and an extended line of one diagonal line imaginarily depicted in the cells in the first honeycomb segment and that in the second are configured to be orthogonal.

A particulate trap filter body has asymmetrical channels. The cross-sectional shape of the asymmetrical channel structure includes a combination of hexagonal, square and triangular shapes. The hexagonal channel and the triangular channel act as inlet channel, and the square channel acts as outlet channel. Compared with the traditional symmetrical filter body structure, the inlet channel volume and filter body wall area can be effectively increased by more than 30%, which means that with capturing the same amount of particles, the particle cake layer formed on the wall surface is thinner. The limiting carbon load of the new channel structure is increased by more than 30%, having a very positive effect on reducing the regeneration frequency and prolonging the service life of the trap.

A honeycomb filter includes a pillar-shaped honeycomb structure body having a porous partition wall disposed to surround a plurality of cells and a plugging portion, wherein the partition wall defining inflow cells includes partition wall parts making up sides of polygon that is sectional shape of each cell, the partition wall parts each having a surface that is a face defining the inflow cell, the partition wall part is either a first partition wall part loaded with the exhaust-gas purifying catalyst on the surface so that a percentage of the area loaded therewith exceeds 10%, or a second partition wall part loaded with the exhaust-gas purifying catalyst so that a percentage of the area loaded therewith is 10% or less, and the partition wall is configured to include one or more the first partition wall parts and one or more the second partition wall parts as the partition wall parts.

A plugged honeycomb structure includes a honeycomb structure body having a porous partition wall disposed to surround a plurality of cells; and a plugging portion disposed at one end of the cells, wherein, in a section orthogonal to the extending direction of the cell, the cells each have a shape that is polygon, and one of the inflow cells and another are adjacent to each other with the partition wall therebetween, and in the section orthogonal to the extending direction of the cell, a total area of the inflow cell is larger than a total area of the outflow cell, a porosity of the partition wall is 38% or more, a thickness of the partition wall is 125 μm or more and 280 μm or less, a cell density of the honeycomb structure body is 31.0 cells/cm.sup.2 or more, and an air-permeability resistance of the partition wall is 4.5×10.sup.7Pa.Math.s/m.sup.2 or less.