A method of plugging a honeycomb body is disclosed herein, the method comprising: applying a mask layer to the honeycomb body defining a plurality of channels, wherein the mask layer defines a plurality of holes aligned with the plurality of channels; rotating a roller drum; moving the honeycomb body over the roller drum to define a nip between the roller drum and the honeycomb body; and inserting a plugging cement in the nip between the roller drum and the mask layer such that the roller drum forces the plugging cement through the plurality of holes of the mask layer into the plurality of channels of the honeycomb body.

An exhaust gas purifying device includes: a columnar honeycomb carrier provided in an exhaust channel; a tubular case member housing the honeycomb carrier; and a retaining member surrounding the outer circumference of the honeycomb carrier. The honeycomb carrier has, in the outer circumferential edge of an inlet-side end face and an outlet-side end face, respectively, sloped surfaces sloped toward a direction in which the length in the center axis direction of the honeycomb carrier decreases. Of the retaining member, ends in the center axis direction of the honeycomb carrier extend to the sloped surfaces of the honeycomb carrier, and the ends have tapered parts which are longer in the center axis direction of the honeycomb carrier on the side facing the case member than on the side facing the honeycomb carrier.

A honeycomb structure includes a honeycomb substrate including latticed partition walls which define a plurality of cells extending from one end face to the other end face and forming through channels for fluid and a honeycomb outer wall, and a flange portion attached to a part of the honeycomb outer wall of the honeycomb substrate, and including latticed flange partition walls which define a plurality of flange cells extending from one flange end face to the other flange end face and a flange outer wall, and in the honeycomb substrate, a ratio of a non-outer wall region in which the honeycomb outer wall is not disposed is in a range of 10 to 90% to a total area of a substrate circumferential surface.

An exhaust gas purification filter that suppresses an increase in pressure loss associated with the formation of a catalyst layer and is excellent in PM burning quality. The exhaust gas purification filter includes a base and a catalyst layer provided on the base. The catalyst layer contains a carrier and a metal catalyst. Large pores having a circle equivalent diameter greater than 5 ?m occupy, when an area of the catalyst layer is 100% in an electron microscope observation image of a cross section of the catalyst layer, 45% or more of the area.

A honeycomb formed body containing a ceramics raw material, he honeycomb formed body including: a pillar shaped honeycomb structure portion having a plurality of rectangular cells, the cells being defined by partition walls and extending from a first end face to a second end face to form flow paths; an outer peripheral portion having outer peripheral portions X where the partition walls are covered with an outer peripheral wall; and outer peripheral portions Y where the partition walls are exposed. Each of the outer peripheral portions X includes a tapered portion having a gradually deceasing thickness of the outer peripheral wall toward a boundary portion with an adjacent outer peripheral portion Y. The tapered portion requires a length equal to or more than one time of an average cell pitch in the outer peripheral direction until thickness of the outer peripheral wall is halved.

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):

The present invention provides a honeycomb filter including a honeycomb fired body including porous cell partition walls, exhaust gas introduction cells each having an open end at an exhaust gas inlet side and a plugged end at an exhaust gas outlet side, exhaust gas emission cells each having an open end at the exhaust gas outlet side and a plugged end at the exhaust gas inlet side, and an outer wall on the periphery thereof. The cross-sectional shape of each exhaust gas introduction cell in a plane perpendicular to the longitudinal direction thereof is entirely uniform from the end at the exhaust gas inlet side to the end at the exhaust gas outlet side excluding the plugged portion. The cross-sectional shape of each exhaust gas emission cell in a plane perpendicular to the longitudinal direction thereof is entirely uniform from the end at the exhaust gas inlet side to the end at the exhaust gas outlet side excluding the plugged portion. The exhaust gas emission cells, except for the cells adjacent to the outer wall, are each adjacently surrounded fully by the exhaust gas introduction cells across the porous cell partition walls. The cells adjacent to the outer wall include the exhaust gas introduction cells and the exhaust gas emission cells. A substantial ratio of the number of the exhaust gas introduction cells to the number of the exhaust gas emission cells (exhaust gas introduction cells:exhaust gas emission cells) is 4:1. All the exhaust gas introduction cells, except for the cells adjacent to the outer wall, have the same cross-sectional area in a plane perpendicular to the longitudinal direction thereof, the cross-sectional area of each exhaust gas introduction cell being smaller than that of each exhaust gas emission cell in a plane perpendicular to the longitudinal direction thereof.

A honeycomb structure prevents catalyst slurry from leaching out when applying a wash coat for making a catalyst supported, ensuring air permeability of the outer portion and in which there is no occurrence of cracking when used as a gasoline particulate filter. The honeycomb structure having: a honeycomb substrate composed of porous partition walls forming a plurality of cells and a porous outer portion; and a resin composition on the outer portion of the honeycomb substrate, wherein the outer portion and the partition walls of the honeycomb substrate are formed of the same material; a porosity of the honeycomb structure is 50% or more; and the resin composition is impregnated into pores of the whole outer portion; and the impregnation depth is equal to the outer portion thickness or a part of the resin composition is impregnated deeper than the outer portion and reaches the cell partition walls.

An air filter article, including: a wall-flow honeycomb particulate filter; and at least one anti-microbial agent on at least a portion of the interior surfaces. The disclosure also provides a filtration system that incorporates or uses the air filter article, and methods for making the air filter article.

A honeycomb structure body has cell walls, inner cells and outer cells, and a boundary partition wall. The inner cells are arranged in a high cell density area and the outer cells are arranged in a low cell density area. A cell density of the high cell density area is higher than a cell density of the low cell density area. Cell reinforced parts are formed at a first intersection part at which the cell walls intersect each other. Boundary reinforced parts are formed at a second intersection part at which the cell walls and the boundary partition wall intersect each other. The honeycomb structure body satisfies a relationship of Sb>Sc, where Sb indicates an average value of a cross sectional area of the overall boundary reinforced parts, and Si indicates an average value of a cross sectional area of the overall inner cell reinforced parts.