A method for manufacturing a pillar-shaped honeycomb fired body including: measuring a firing shrinkage at an end surface of a first pillar-shaped honeycomb firing body at every predetermined angle for one round based on a portion that has been located at the center of a die when a green body passes through the die, obtaining a second pillar-shaped honeycomb formed body having a corrected end surface contour by modifying an annular mask used for extrusion molding based on a result of the measuring, and then obtaining a second pillar-shaped honeycomb fired body by performing drying and firing.

A method for manufacturing a pillar-shaped honeycomb fired body including: measuring a firing shrinkage at an end surface of a first pillar-shaped honeycomb firing body at every predetermined angle for one round based on a portion that has been located at the center of a die when a green body passes through the die, obtaining a second pillar-shaped honeycomb formed body having a corrected end surface contour by modifying an annular mask used for extrusion molding based on a result of the measuring, and then obtaining a second pillar-shaped honeycomb fired body by performing drying and firing.

A method for producing a honeycomb-shaped ceramic structure by extrusion-molding a moldable material including a cordierite-forming material and a pore-forming material, wherein the cordierite-forming material contains 15-25% by mass of silica having an average particle size of 20-30 μm, with 5% or less by mass of particles having particle sizes of 10 μm or less and 5% or less by mass of particles having particle sizes of 100 μm or more, a particle size distribution deviation SD of 0.5 or less, and sphericity of 0.5 or more, and wherein the pore-forming material is present in an amount of 5-40% by mass based on the cordierite-forming material and has an average particle size of 15-50 μm, with 10% or less by mass of particles having particle sizes of 5 μm or less and 5% or less by mass of particles having particle sizes of 80 μm or more.

A method for producing a honeycomb-shaped ceramic structure by extrusion-molding a moldable material including a cordierite-forming material and a pore-forming material, wherein the cordierite-forming material contains 15-25% by mass of silica having an average particle size of 20-30 μm, with 5% or less by mass of particles having particle sizes of 10 μm or less and 5% or less by mass of particles having particle sizes of 100 μm or more, a particle size distribution deviation SD of 0.5 or less, and sphericity of 0.5 or more, and wherein the pore-forming material is present in an amount of 5-40% by mass based on the cordierite-forming material and has an average particle size of 15-50 μm, with 10% or less by mass of particles having particle sizes of 5 μm or less and 5% or less by mass of particles having particle sizes of 80 μm or more.

A honeycomb ceramic substrate, a method of making thereof, and a honeycomb extrusion die configured to extrude a honeycomb ceramic substrate from a batch of ceramic or ceramic-forming material is provided. The substrate may include a lattice of intersecting walls defining a honeycomb network of flow channels extending between an inlet end and an outlet end of the honeycomb substrate. Each flow channel may be defined by a plurality of channel walls of the intersecting walls with at least two of the plurality of channel walls including concave inner surfaces facing a center of the corresponding flow channel from central portions of the concave inner surfaces to concave corner portions facing the center of the corresponding flow channel.

A honeycomb ceramic substrate, a method of making thereof, and a honeycomb extrusion die configured to extrude a honeycomb ceramic substrate from a batch of ceramic or ceramic-forming material is provided. The substrate may include a lattice of intersecting walls defining a honeycomb network of flow channels extending between an inlet end and an outlet end of the honeycomb substrate. Each flow channel may be defined by a plurality of channel walls of the intersecting walls with at least two of the plurality of channel walls including concave inner surfaces facing a center of the corresponding flow channel from central portions of the concave inner surfaces to concave corner portions facing the center of the corresponding flow channel.

A honeycomb structure includes a honeycomb structure body having a partition wall which is constituted of a porous body. The porous body includes a refractory aggregate and a bonding material. The porous body constituting includes the bonding material at a mass proportion of 20 to 35 mass %. In an observation of a cross section of the partition wall with an electron microscope, when observing any given ten visual fields meeting a following condition (1), the number of refractory aggregates meeting a following condition (2) is five pieces or more in all of the ten visual fields. Condition (1): a proportion of an area occupied by the bonding material is 30% or more. Condition (2): the refractory aggregate has a particle diameter of 5 μm or more, and 60% or more of an outer circumference of the refractory aggregate is surrounded by the bonding material.

A honeycomb structure includes a honeycomb structure body having a partition wall which is constituted of a porous body. The porous body includes a refractory aggregate and a bonding material. The porous body constituting includes the bonding material at a mass proportion of 20 to 35 mass %. In an observation of a cross section of the partition wall with an electron microscope, when observing any given ten visual fields meeting a following condition (1), the number of refractory aggregates meeting a following condition (2) is five pieces or more in all of the ten visual fields. Condition (1): a proportion of an area occupied by the bonding material is 30% or more. Condition (2): the refractory aggregate has a particle diameter of 5 μm or more, and 60% or more of an outer circumference of the refractory aggregate is surrounded by the bonding material.

A particulate filter having a porous ceramic honeycomb structure with a first end, a second end, and a plurality of walls having wall surfaces defining a plurality of inner channels. Filtration material deposits are disposed on one or more of the wall surfaces of the honeycomb body. The highly porous deposits provide durable high clean filtration efficiency with small impact on pressure drop through the filter.

A particulate filter having a porous ceramic honeycomb structure with a first end, a second end, and a plurality of walls having wall surfaces defining a plurality of inner channels. Filtration material deposits are disposed on one or more of the wall surfaces of the honeycomb body. The highly porous deposits provide durable high clean filtration efficiency with small impact on pressure drop through the filter.