Abstract: A honeycomb filter including: a pillar-shaped honeycomb structure having an inflow end face and an outflow end face and including a porous partition wall disposed so as to surround a plurality of cells, the plurality of cells extending from the inflow end face to the outflow end face; inflow side plugging portions disposed at open ends of predetermined cells on the inflow end face side; and outflow side plugging portions disposed at open ends of residual cells on the outflow end face side, wherein the outflow side plugging portions comprise first outflow side plugging portions and second outflow side plugging portions, the plugging length L1 of the first outflow side plugging portions is 10 to 50% of the overall length L0 of the honeycomb structure, and the plugging length L2 of the second outflow side plugging portions is less than 10% of the overall length L0 of the honeycomb structure.

Abstract: A bottom face processing method of a pillar-shaped honeycomb structure including steps of: preparing a pillar-shaped honeycomb structure including a plurality of first cells which extend in parallel with each other from a first bottom face to a second bottom face, and each of which is opened in the first bottom face and has a protruding plugged portion in the second bottom face, and a plurality of second cells each of which is adjacent to at least one of the first cells with a partition wall interposed therebetween, which extend in parallel with each other from the first bottom face to the second bottom face, and each of which has a protruding plugged portion in the first bottom face, and is opened in the second bottom face; and removing the protruding portion from the plugged portion of each of the first cells and the second cells of the pillar-shaped honeycomb structure.

Abstract: 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 ?m or more and 280 ?m or less, a cell density of the honeycomb structure body is 31.0 cells/cm2 or more, and an air-permeability resistance of the partition wall is 4.5×107Pa·s/m2 or less.

Abstract: A method for producing a honeycomb structure, the method including: a step of drying a pillar-shaped honeycomb formed body including partition walls that define a plurality of cells each forming a flow path penetrating from a first end face to a second end face; and after the step of drying, a step of cooling the honeycomb formed body by applying a suction force to the first end face of the honeycomb formed body to allow a coolant to flow in the honeycomb formed body from the second end face, pass through the cells, and flow out from the first end face.

Abstract: A masking method for honeycomb formed body, including bonding a film on at least one bottom face of a honeycomb formed body in a quadrangular prism shape such that an adhesive surface is in contact with the bottom face. The step of bonding the film includes bonding of the film so as to have a bottom face covering portion that covers a whole surface of the bottom face and a pair of outer edge portions along one pair of opposite sides of a quadrangle defining an outer peripheral shape of the bottom face and a pair of protruding portions protruding from another pair of opposite sides of the quadrangle. At least a part of the adhesive surface of each of the pair of protruding portions is bonded so as to be in contact with a pair of opposing lateral faces of the honeycomb formed body.

Abstract: A honeycomb filter including: a pillar-shaped honeycomb structure having an inflow end face and an outflow end face and including a porous partition wall disposed so as to surround a plurality of cells, the plurality of cells extending from the inflow end face to the outflow end face; inflow side plugging portions disposed at open ends of predetermined cells on the inflow end face side; and outflow side plugging portions disposed at open ends of residual cells on the outflow end face side, wherein the outflow side plugging portions comprise first outflow side plugging portions and second outflow side plugging portions, the plugging length L1 of the first outflow side plugging portions is 10 to 50% of the overall length L0 of the honeycomb structure, and the plugging length L2 of the second outflow side plugging portions is less than 10% of the overall length L0 of the honeycomb structure.

Abstract: A method for producing a honeycomb structure for fine particle collection filters. The honeycomb structure includes a plurality of porous honeycomb segments joined together via joining material layers. The method includes the steps of: forming the outer peripheral wall of each of the porous honeycomb segments so as to have a thickness thicker by a grinding margin; drying the porous honeycomb segments each formed by grinding the outer peripheral wall so as to have the thickness thicker by the grinding margin; firing the dried porous honeycomb segments; grinding and removing the grinding margin of the outer peripheral wall of each of the fired porous honeycomb segments; and applying a joining material to each of the porous honeycomb segments with the grinding margin ground and removed, between joining surfaces of each of the porous honeycomb segments, to join the porous honeycomb segments via the joining material layers.

Abstract: A method for producing a honeycomb structure, the method including: a step of drying a pillar-shaped honeycomb formed body including partition walls that define a plurality of cells each forming a flow path penetrating from a first end face to a second end face; and after the step of drying, a step of cooling the honeycomb formed body by applying a suction force to the first end face of the honeycomb formed body to allow a coolant to flow in the honeycomb formed body from the second end face, pass through the cells, and flow out from the first end face.

Abstract: A masking method for honeycomb formed body, including bonding a film on at least one bottom face of a honeycomb formed body in a quadrangular prism shape such that an adhesive surface is in contact with the bottom face. The step of bonding the film includes bonding of the film so as to have a bottom face covering portion that covers a whole surface of the bottom face and a pair of outer edge portions along one pair of opposite sides of a quadrangle defining an outer peripheral shape of the bottom face and a pair of protruding portions protruding from another pair of opposite sides of the quadrangle. At least a part of the adhesive surface of each of the pair of protruding portions is bonded so as to be in contact with a pair of opposing lateral faces of the honeycomb formed body.

Abstract: A bottom face processing method of a pillar-shaped honeycomb structure including steps of: preparing a pillar-shaped honeycomb structure including a plurality of first cells which extend in parallel with each other from a first bottom face to a second bottom face, and each of which is opened in the first bottom face and has a protruding plugged portion in the second bottom face, and a plurality of second cells each of which is adjacent to at least one of the first cells with a partition wall interposed therebetween, which extend in parallel with each other from the first bottom face to the second bottom face, and each of which has a protruding plugged portion in the first bottom face, and is opened in the second bottom face; and removing the protruding portion from the plugged portion of each of the first cells and the second cells of the pillar-shaped honeycomb structure.

Abstract: A method for manufacturing a plugged honeycomb structure including a step of mixing ceramic particles with a gas on one end face side of the plugged honeycomb structure, and a step of sucking the gas containing the ceramic particles from the other end face side of the plugged honeycomb structure to send the ceramic particles mixed in the gas into cells of the plugged honeycomb structure to allow the ceramic particles to adhere to surfaces in the cells of the plugged honeycomb structure.

Abstract: A method for manufacturing a plugged honeycomb structure includes: a step of mixing ceramic particles with a gas on one end face side of the plugged honeycomb structure, and a step of sucking the gas containing the ceramic particles from the other end face side of the plugged honeycomb structure to send the ceramic particles mixed in the gas into cells of the plugged honeycomb structure to allow the ceramic particles to adhere to surfaces in the cells of the plugged honeycomb structure.