Abstract: 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%.

Abstract: 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%.

Abstract: There is disclosed a ceramic honeycomb structure which is not easily damaged and is excellent in durability even in a case where irregular canning conditions such as an overload and an offset load are generated. The ceramic honeycomb structure has a cell tilt angle of 0.5° or more and 35° or less and a substantially elliptic or oblong sectional shape vertical to a central axis direction.