A honeycomb filter comprising a pillar-shaped honeycomb structure having a porous partition wall disposed so as to surround a plurality of cells which serve as a fluid through channel extending from an inflow end face to an outflow end face and a porous plugging portion provided at either an end on the inflow end face side or an end on the outflow end face side of the cell, wherein in a processed image obtained by binarizing an electron microscope image of a visual field area of 480 m640 m of the plugging portion, the plugging portion is composed of a plurality of particles, and the number of the particles having an area of 0.25 m.sup.2 or more is 1000 or more and 3500 or less.

A honeycomb body having intersecting porous walls which includes first through fourth cells, wherein the cells extend from inlet to outlet face and are plugged to define a repeating structural unit with three inlets and one outlet channel. Repeating structural unit includes a first channel including length L.sub.1, width W.sub.2, and area A.sub.1, a second channel including length L.sub.2, the width W.sub.2, and area A.sub.2, a third channel including the length L.sub.1, width W.sub.1, and area A.sub.3, and a fourth channel including the length L.sub.2, the width W.sub.1, and A.sub.4, wherein the first through third channels are inlets and the fourth channel is a rectangular outlet and at least one of W.sub.1>W.sub.2 and L.sub.1L.sub.2, i.e. W.sub.1>W.sub.2, or L.sub.1L.sub.2, or W.sub.1>W.sub.2 and L.sub.1L.sub.2. Repeating structural unit has a quadrilateral outer perimeter. Particulate filters including the honeycomb body, honeycomb extrusion dies, and methods of manufacturing the honeycomb body are provided.

A particulate filter for exhaust-gas aftertreatment in an internal combustion engine has a housing on which an inlet and an outlet are configured on opposite ends. The particulate filter also has a filter element arranged in the housing, said filter element having essentially parallel filter channels that are each alternatingly closed on the inlet side or on the outlet side by a closure in order to prevent gas from passing directly through the filter element. In this context, the filter channels can be divided into a first group of filter channels which are closed on the outlet side by a closure, and into a second group of filter channels which are closed on the inlet side by a gas-tight closure. The filter channels of the second group are additionally closed on the outlet side by a high-porosity closure in order to improve the cleaning effect of the particulate filter.

A honeycomb filter including: a pillar-shaped honeycomb structure including porous partition walls; and porous plugging portions disposed on either one of end portions of each of the cells, wherein a porosity (%) of the partition walls is defined as P1, a porosity (%) of the plugging portions is defined as P2, an occupancy (%) of the partition walls relative to an area of a cross section orthogonal to an extending direction of the cells of the honeycomb structure is defined as N1, the P1 is 50 to 65%, the P2 is 60 to 70%, the N1 is 22 to 39%, and X represented by Formula (1) satisfies a relation of Formula (2):
X=P1/P2N1,Formula (1):
18.800.19X.sup.2+11.33X121.6350.50.Formula (2):

A honeycomb filter includes a pillar-shaped honeycomb substrate and a plugging portion provided at an end portion on either an inflow or outflow end face side of cells, wherein, in a section orthogonal to the cell extending direction, the shapes of an inflow cell having the plugging portion and an outflow cell having the plugging portion are hexagonal. In the plurality of cells, a plurality of inflow cells surround one outflow cell such that one side of the inflow cell and one side of the outflow cell adjacent to the inflow cell are parallel. The partition wall includes a first partition wall and a second partition wall, at least one of the first partition walls is configured such that a ratio of a thickness of the second partition wall to the first partition wall is 1.0 to 2.5, and a total open frontal area is 35% to 95%.

An exhaust gas purification filter includes a plurality of cells each extending from an inflow end face to an outflow end face, a porous partition wall forming the cells in a partitioned manner, inflow-side sealing parts sealing openings on an inflow end face side of outflow cells where the exhaust gas flows out, and outflow-side sealing parts sealing openings on an outflow end face side of inflow cells where the exhaust gas flows in. Each of the inflow-side sealing parts has a porosity of less than 60%. The partition wall has a porosity of 60% or more and 70% or less. Assuming a pore size, at which cumulative pore volume is 50% in pore size distribution of the inflow-side sealing parts, is d50.sub.Pin, and a pore size, at which cumulative pore volume is 50% in pore size distribution of the partition wall, is d50.sub.B, the pore size d50.sub.Pin is less than 18 m, and the pore size d50.sub.B is 18 m or more and 25 m or less.

An exhaust gas purification filter includes a plurality of cells extending in a filter axial direction, a porous partition separating and defining the plurality of cells, and a sealing section sealing the plurality of cells alternately at both filter ends. The partition has a void volume of a reduced dale, Vvv, and a material volume of a reduced peak, Vmp, as volume parameters determined in noncontact surface roughness measurement on a surface of the partition, with their total value being more than 1.3 m.sup.3/m.sup.2 and 1.7 m.sup.3/m.sup.2 or less. The partition has a mean pore size of 12 m or more and 20 m or less. The partition also has a porosity of 50% or more and 75% or less.

Provided is a honeycomb filter, including: a pillar-shaped honeycomb substrate having an inflow end face and an outflow end face and including a porous partition wall surrounding a plurality of cells; and a plugging portion disposed at any one of ends of the cells at the inflow end face and at the outflow end face. In a cross section orthogonal to an extending direction of the cells, inflow cells have a pentagonal or a hexagonal shape, and outflow cells have a square shape. The cells are configured that the inflow cells surround one outflow cell and one side of an inflow cell and one side of an adjacent outflow cell are parallel to each other. The partition wall is configured that thickness of a first partition wall disposed between the inflow cells and the outflow cells is smaller than thickness of a second partition wall disposed between the inflow cells.

A honeycomb body (100) having a porous ceramic honeycomb structure with a first end (105), a second end (135), and a plurality of walls (115) having wall surfaces defining a plurality of inner channels (110). A porous material is disposed on one or more of the wall surfaces of the honeycomb body (100). A method for forming a honeycomb body (100) includes depositing a porous inorganic material on a ceramic honeycomb body (100) and binding the porous inorganic material to the ceramic honeycomb body (100) to form the porous layer.

A silicon carbide ceramic honeycomb structure having large numbers of axially penetrating flow paths partitioned by porous silicon carbide cell walls, the cell walls comprising silicon carbide particles as aggregate and binder layers for binding the silicon carbide particles, the binder layers having at least a cordierite phase and a spinel phase, and the molar ratio M1 of the cordierite phase [=cordierite phase/(cordierite phase+spinel phase)] being 0.4-0.9.