A method of plugging channels of a honeycomb body and a honeycomb body including plugged channels. The method includes applying a shear force to a plugging mixture including a plurality of inorganic particles, clay, and a liquid vehicle to alter the viscosity of the plugging mixture from a first viscosity prior to the vibrating to a second viscosity which is less than the first viscosity. A honeycomb body is placed into contact with the plugging mixture such that a portion of the plugging mixture having the second viscosity flows into the plurality of channels. Application of the shear force is stopped or reduced to increase the viscosity of the portion of the plugging mixture in the plurality of channels to greater than the first viscosity.

An exhaust gas purification filter collects PM contained in and purifies exhaust gas emitted from a gasoline direct injection engine. The exhaust gas purification filter has a honeycomb structural body which has a plurality of cells, partition walls and plug members. Each of the cells is surrounded by the partition walls. An opening section of one end of each of the cells is plugged by a plug member. The plug members satisfies a relationship of L/D50 and L3, where L is an average length (mm) of the plug members and D is an average pore size mm of the plug members. The honeycomb structural body and the plug members are made of cordierite. The cordierite contains silica, talc, kaolin, alumina and/or aluminum hydroxide, etc.

A honeycomb filter includes a honeycomb structure having a porous partition wall and a plurality of plugging portions, wherein a porosity of the plugging portion is 40 to 60%, a central plugging portion having a plugging length of 5 mm or more and an outer peripheral plugging portion having the plugging length of less than 5 mm are disposed, an average plugging length L1.sub.(Ave) is 5 mm or more and 10 mm or less, an average plugging length L2.sub.(Ave) is 2 mm or more and less than 5 mm, a difference between L1.sub.(Ave) and L2.sub.(Ave) is 2 to 6 mm, a ratio of an average radius of the center part to an equivalent circle diameter of the end face is 0.2 to 0.5, the plugging portion is composed of a plurality of particles, an average value of an equivalent circle diameter of each particle is 3 to 5 ?m, and a particle density is 750 to 1250 particles/mm.sup.2.

An exhaust gas treating device includes a honeycomb structure including an inner honeycomb structure body, an outer honeycomb structure body disposed at a position which surrounds a part of a circumference of the inner honeycomb structure body and is away from the inner inflow end face of the inner honeycomb structure body, and plugging portions arranged in parts of cells; a can member which stores the honeycomb structure and has an inlet and a second outlet for an exhaust gas; and an opening/closing valve to open and close the second outlet of the can member.

An exhaust gas treating device includes a honeycomb structure including an inner honeycomb structure body including a honeycomb substrate having porous inner partition walls and a circumferential wall disposed at a circumference of the honeycomb substrate, an outer honeycomb structure body disposed at a position which surrounds a part of a circumference of the inner honeycomb structure body and is away from the inner inflow end face, and plugging portions; and a can member storing the honeycomb structure. The can member includes an inflow tube and a barrel portion which is continuous with the inflow tube, and in the barrel portion an outlet is formed, the honeycomb structure is stored in the can member in a state of having a clearance between a second end face and the can member and having a clearance between the outer outflow end face and the can member.

An exhaust system includes an exhaust gas treatment article having a porous ceramic honeycomb body mounted in a housing. The exhaust gas treatment article includes a thermal barrier disposed at the outer peripheral surface of the honeycomb body, wherein the thermal barrier comprises blocked peripheral cell channels adjacent to and around the entire peripheral surface and/or a thermal barrier skin.

Provided are catalyst articles, methods of manufacturing catalyst articles, and methods for controlling emissions in diesel engine exhaust streams with catalyst articles, where the emission treatment system of various embodiments effectively treats diesel engine exhaust with a catalyst article. In one or more embodiments, the catalyst articles have a platinum group metal end coating covering an outlet end surface of the catalytic article. In one or more embodiments, a method is provided where an applicator transfers a platinum group metal coating to an outlet end face of a catalytic article.

An exhaust gas purifying device includes: a columnar honeycomb carrier in which a plurality of cells which extend from an exhaust gas inflow side to an outflow side, and which serve as exhaust gas flow paths, are demarcated and formed by means of porous separating walls, a three-way catalyst supported in the honeycomb carrier, and a cylindrical case member in which the honeycomb carrier is housed, with the interposition of a retaining member. The honeycomb carrier includes outer circumferential plugging portions formed in such a way as to plug, to a prescribed depth, openings of cells in an outer circumferential portion of at least one end surface of the two end surfaces, in the central axis X-direction, of the honeycomb carrier, and inclined portions formed in a direction whereby the length, in the central axis X-direction, of the outer circumferential plugging portions decreases toward the outer circumferential edge.

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 in which at least the inflow cells are included and in which in the cross section perpendicular to the extending direction of the cells, a through channel area SA occupied by the inflow cells is larger than a through channel area SB occupied by the outflow cells, and a second cell row in which at least the outflow cells are included. A width P1 (mm) of the first cell row, a width P2 (mm) of the second cell row and a curvature radius R (m) of a curved shape of corner portions of a polygonal shape of each cell satisfy a relation of Equation (1) below: Equation (1): 0.4(R/1000)/((P1+P2)/2)10020.

A composition for applying to a honeycomb body includes a refractory filler, an organic binder, an inorganic binder, and a liquid vehicle, wherein the refractory filler, the particle size distribution of the refractory filler, the organic binder, and the inorganic binder are selected such that, when the composition is applied to plug a plurality of channels of the honeycomb body, the plug depth variability is reduced.