Abstract: A precise exhaust gas control can be achieved without being influenced by fluctuations of the excess air ratio (?) between cylinders of engines or the size of the diameter (the sectional area) of the honeycomb structure. The honeycomb structure is formed by a plurality of cells separated from one another by porous partition walls and functioning as fluid flow paths, the honeycomb structure includes: a sensor plug-in hole 7 which is formed in an outer peripheral surface 4 of the honeycomb structure and into which a sensor can be plugged, and the sensor plug-in hole 7 is provided with at least one deep hole 8 which communicates with the sensor plug-in hole.

Abstract: A honeycomb structure 1 of the present invention includes: a cylindrical cell structure 2 having porous partition walls and a plurality of cells separated and formed by the partition walls and functioning as fluid passages, and an outer peripheral coat layer 3 disposed so as to cover the outer periphery of the cell structure 2, and the outer peripheral coat layer 3 has an outer peripheral coat portion 6 disposed so as to cover the outer periphery of the cell structure 2 and a protruding portion protruding outside from an end face 8 of the cell structure 2 and disposed so as to cover the outside portion on the end face 8 of the cell structure 2. In the honeycomb structure 1 of the present invention, the outer peripheral coat layer 3 is effectively inhibited from being damaged and peeled.

Abstract: A method for determining the charge state of a particle filter installed in the exhaust gas line of an internal combustion engine comprises the following steps: determining the exhaust gas volumetric flow in the flow direction of the exhaust gas downstream of the particle filter (2), detecting the pressure present in the exhaust gas line (1) in the direction of flow of the exhaust gas prior to the particle filter (2), comparing the exhaust gas volumetric flow determined hinter the particle filter (2) with the detected pressure present upstream of the particle filter (2) and evaluating the results of the comparison with consideration to the exhaust gas back pressure of the uncharged particle filter (2) and the exhaust gas back pressure caused by the particle filter charge, said pressure being higher than the uncharged filter. Further described is a corresponding device for reducing the particle emissions of an internal combustion engine.

Abstract: A porous membrane, comprising a blend of a first powder of metal particles of the first average size and a second powder of metal particles of a second average size, the first powder and the second powder sintered together. The first average size is five to fifty times greater than the second average size. The porous membrane comprises from 40% to 60% by weight of the first powder.

Abstract: The invention is to provide a process for producing an aluminum titanate-based ceramics body, wherein, as a regenerated starting material, a fired body recovered in a production process for an aluminum titanate-based ceramics body is used and the aluminum titanate-based ceramics body excellent in a mechanical strength and in a thermal characteristics such as low thermal expansion and heat resistance can be obtained. The invention provides a process for producing an aluminum titanate-based ceramics body using a fired ceramics body recovered in a production process for an aluminum titanate-based ceramics body, comprising the following steps: a step of preparing a pulverized product having a median particle diameter of 100 ?m or less from the fired ceramics body; a step of preparing a regenerated clay containing the pulverized product and water; a step of shaping the regenerated clay to form a shaped body; and a step of firing the shaped body.

Abstract: There is disclosed a honeycomb structure having a plurality of segments and each including a plurality of cells, wherein each segment has a porous base material having the honeycomb shape, and a modified portion formed by impregnating a part of the base material with a slurry including particles smaller than the average pore diameter of the base material, followed by a heat treatment, the base material has a porosity of 30 to 80% and an average pore diameter of 5 to 40 ?m, and the modified portion is partially formed on the section of the segment vertical (orthogonal) to the axial direction of the cells, and has a porosity which is 2 to 20% lower than that of the base material and an average pore diameter which is 0.1 to 10 ?m smaller than that of the base material.

Abstract: A first intake air control mode of setting an intake throttle valve to (or close to) a fully-opened state and setting an EGR valve to (or close to) a fully-closed state is performed when DPF temperature and a particulate matter deposition quantity are greater than corresponding predetermined values respectively, a no-injection operation state exists, and engine rotation speed is higher than a corresponding predetermined value. A second intake air control mode of setting the intake throttle valve to (or close to) a fully-closed state and setting the EGR valve to (or close to) a fully-opened state is performed when the DPF temperature and the particulate matter deposition quantity are greater than the corresponding predetermined values respectively, the no-injection operation state exists, and the engine rotation speed is lower than the corresponding predetermined value.

Abstract: An exhaust gas control apparatus (2) for an engine includes a filter case (3) that has an internal space; a filter (4) that is arranged in the filter case (3) and that purifies exhaust gas; and a mat (5) that is arranged, in a compressed state, between the filter case (3) and the filter (4). The filter (4) is arranged in the filter case (3) with a first flange (45) of the filter (4) engaged with the mat (5) and with a second flange (46) engaged with a retainer (6).

Abstract: Provided is a honeycomb structure that is divided by a porous partition wall 3, as well as that is formed of a plurality of cells 5 acting as a through channel of a fluid. An insertion hole 9 in which a sensor can be inserted is formed in an end face of the honeycomb structure, and a breakage prevention means 17 is provided on an inner circumference or in the proximity of the insertion hole. According to this honeycomb structure, it is possible to provide a honeycomb structure or a honeycomb filter in which a temperature, an oxygen concentration and the like of the honeycomb structure can be directly measured; a temperature control of the honeycomb structure, being a base member can be easily made, and various sensors in accordance with applications of OBD measurement, measurement of an oxygen concentration, an NOx concentration and the like can be attached; and further, canning is easy to be conducted, and the durability of various attached sensors can be improved.

Abstract: The present disclosure relates to aluminum titanate-containing ceramic-forming batch materials and methods using the same.

Abstract: An object of the present invention is to provide a honeycomb filter for purifying exhaust gases which makes it possible to alleviate a thermal stress generated due to occurrence of a local temperature change and which is less likely to generate cracks and superior in strength and durability, an adhesive that has a low thermal capacity and is capable of alleviating the thermal stress, a coating material that has a low thermal capacity with a superior heat insulating property and is capable of alleviating the thermal stress, and a manufacturing method of the honeycomb filter for purifying exhaust gases that can improve precision in the outside dimension, and reduce damages in the manufacturing processes.

Abstract: There is provided a ceramic filter capable of controlling extraordinary rise of the internal temperature upon regeneration by reducing an amount of deposited soot (particulates) by increasing a passage flow rate in the through-cells and realizing improvement of the regeneration limit and correspondence of PM emission and a method for manufacturing a ceramic filter. A plurality of through channels 7 are formed in the honeycomb segment 2, and the cells are constituted as inlets and/or outlets of the through channels 7 and contain a plurality of honeycomb segments 2 bonded to one another. Each honeycomb segment 2 includes a first inflow port 8, a second inflow port 9, and as a part at least through-cells 10 formed to extend there through in such a manner that fluid can be discharged from the inlet to the outlet of the cells without being plugged at the inlet and the outlet of the cell.

Abstract: Cellular ceramic articles are manufactured from a green cellular ceramic body that includes a binder material and a plurality of channels. At least one of the channels is coated with a slurry that includes a green coating composition and a solvent to form a coating layer. The binder material is insoluble in the solvent.

Abstract: Provided is an emission treatment system and method for simultaneously remediating the nitrogen oxides (NOx), particulate matter, and gaseous hydrocarbons present in diesel engine exhaust streams. The emission treatment system has an oxidation catalyst upstream of a soot filter coated with a material effective in the Selective Catalytic Reduction (SCR) of NOx by a reductant, e.g., ammonia. Also provided is a method for disposing an SCR catalyst composition on a wall flow monolith that provides adequate catalyst loading, but does not result in unsuitable back pressures in the exhaust.

Abstract: A particulate matter (PM) filter includes filter walls having inlet ends and outlet ends. First adjacent pairs of the filter walls define inlet channels. Second adjacent pairs of the filter walls define outlet channels. Outlet end plugs are arranged in the inlet channels adjacent to the output ends. Inlet end plugs arranged in the outlet channels spaced from the inlet ends.

Abstract: A honeycomb ceramic filtration substrate, a filter made of the said substrate and a filter system made of the said filter and their production methods are published in the present invention. The said substrates are extruded with a paste comprising (by portion): SiC: 1; Clay: 0.05-0.5; Flour: 0.1-0.35; grease: 0.025-0.05; Water: 0.2-0.35. The said sintered substrate has a honeycomb structure with cells density ranging from 4˜62 cells/cm2; The cell wall thickness is: 0.2-1.2 mm; The porosity of the cell wall: 40-70%. The cell wall through pore rate is more than 30%; The average diameter distribution of the cell wall micro-pores is in the ranging of 1-50 ?m. The said substrate can be designed in different cylinders whose cross section are in form of square, one border curved square and one border curved triangle etc., After adhering the substrates, the filter can be used as vehicle particulates filter. After the canning of the filter, the filter system is produced.

Abstract: A method of manufacturing a honeycomb body is disclosed having the steps of mixing inorganic source materials, a nut shell pore former, and forming aids to form a plasticized batch, wherein the nut shell pore former has a particle size distribution with 20 ?m?dp50?70 ?m, and forming the plasticized batch into the honeycomb body having a plurality of channels formed by intersecting walls. Green honeycombs and porous ceramic honeycombs produced by the method are also disclosed.

Abstract: An object of the present invention is to provide a honeycomb structural body which is low in pressure loss and can prolong a period up to a regenerating process. The present invention is directed to a columnar honeycomb structural body comprising a large number of through holes placed in parallel with one another in a length direction with wall portion interposed therebetween, wherein: each of the through holes has one of ends sealed; one end face of the through hole differs in opening area from the other end face thereof; a ceramic material which constitutes the wall portion has an average pore diameter in a range from 5 to 30 ?m; and the rate of capacity of micro pores each having a pore diameter two or more times larger than the average pore diameter is set to 30% or less of the capacity of the entire micro pores.

Abstract: A honeycomb structure is disclosed that includes plural through-holes separated by plural partition walls and provided in parallel along a longitudinal direction, wherein the thickness of each of the partition walls is less than or equal to about 0.25 mm, the length of each of the through-holes is equal to or greater than about 50-fold of a hydraulic diameter of each of the through-holes and less than or equal to about 350-fold of the hydraulic diameter of each of the through-holes, and an open area ratio (X) % of a cross section of the honeycomb structure perpendicular to the through-holes and a surface area per unit volume (Y (m2/L)) satisfy Y?250×X+22500 (about 50?X?about 85).

Abstract: A ceramic honeycomb structure having a large number of flow paths defined by porous cell walls; said porous cell walls being composed of cordierite crystals, mullite crystals, corundum crystals and/or spinel crystals; the percentage of the X-ray diffraction intensity of the cordierite crystals being 72% or more and less than 85%, the percentage of the X-ray diffraction intensity of the mullite crystals being 15-25%, and the percentage of the total X-ray diffraction intensity of the corundum crystals and the spinel crystals being 5% or less, per the total X-ray diffraction intensity of these crystals; said porous cell walls having a true density of 2.55-2.70 g/cm3, a mean pore diameter of 10-20 ?m, and a porosity of 50-65%; the volume of pores having diameters exceeding 50 ?m being 8-25% of the total pore volume, the volume of pores having diameters of less than 10 ?m being 16-25% of the total pore volume, and the pore diameter distribution deviation ? being 0.5 or less.

Abstract: The present invention relates to a structure, for filtering particulate-laden gases, of the honeycomb type and containing an assembly of adjacent ducts or channels, whose axes are parallel to one another, separated by porous walls, the ducts being sealed off by plugs at one or other of their ends so as to form inlet chambers opening onto a gas entry face and outlet chambers opening onto a gas exit face, in such a way that the gas to be filtered passes through the porous walls, wherein said walls comprise material based on silicon carbide and the walls have an open porosity of between 30 and 53%; a median pore diameter of between 9 and 20 ?m; the average number of open pores on the surface of the walls, the opening area of which is between 20 and 310 ?m2, is greater than 300 per mm2 of wall; and the ratio of the total opening area of said open pores to said area of the walls is between 0.15 and 0.30.

Abstract: A system comprises a particulate matter (PM) filter that comprises an upstream end for receiving exhaust gas, a downstream end and at least one portion. A control module initiates combustion of PM in the PM filter using a heater and selectively adjusts oxygen levels of the exhaust gas to adjust a temperature of combustion adjacent to the at least one portion of the PM filter. A method comprises providing a particulate matter (PM) filter that comprises an upstream end for receiving exhaust gas, a downstream end and at least one portion; initiating combustion of PM in the PM filter using a heater; selectively adjusting oxygen levels of the exhaust gas to adjust a temperature of combustion adjacent to the at least one portion of the PM filter.

Abstract: A porous structure sealed at both ends for use in a gas separation module; and a method for separating components of a gas stream.

Abstract: A composite is formed by inserting a ceramic powder into a channel of a preform to form a ceramic powder filled preform. The ceramic powder has at least one reactive ceramic powder. The preform is a ceramic, ceramic-metal composite, metal or combination thereof that has walls that define a plurality of channels each channel having an opening at a surface of the preform. The ceramic powder filled preform is infiltrated with a molten metal to form the ceramic-metal body, which has at least one ceramic phase that is a reaction product of the reactive ceramic and molten infiltrated metal.

Abstract: Proposed is a diesel particle filter which comprises a ceramic wall-flow filter substrate and a coating applied in the inflow ducts, which coating is composed of material with a high melting point. The coating (6) is provided such that, by means of said coating, pores (5), which connect the inflow ducts (1) and outflow ducts (2), in the wall (4) are closed off for the soot particles (7) at the inflow side without said coating thereby preventing the passage of the gaseous exhaust-gas constituents. The coating may be produced from one or more oxides with a high melting point or from fibrous material with a high melting point. In both cases, the coating has the effect that the depth filtration is considerably reduced, and therefore the back pressure increase encountered during the depth filtration phase is significantly reduced.

Abstract: Sintered fiber filters are provided that can afford high particle capture efficiency and/or low pressure drop during operation, and are useful in applications such as semiconductor processing. The shape of at least a portion of the individual fibers (e.g., metal fibers) used to make the filter have a three-dimensional aspect, which allows for a low packing density and high porosity filtration media. Certain filters have a cylindrical or tube-like shape with tapered ends of higher density. Methods of making such filters, for example, using axial pressing, are also described.

Abstract: A control system includes a heater control module, a measured duration module, and a regeneration volume module. The heater control module selectively initiates a regeneration in a zone of a particulate filter in an exhaust system. The measured duration module measures a duration of the regeneration. The regeneration volume module determines an available volume within the particulate filter to regenerate particulate based on the measured duration of the regeneration.

Abstract: There is provided a honeycomb filter wherein particles having an average particle diameter smaller than the average pore diameter of partition walls are deposited at least in open pores formed in the surface layer of the partition wall and in the pores of the partition wall in a surface layer portion of the partition walls on the exhaust gas inflow side, thereby forming a composite region. The average pore diameter of the partition walls is 5 to 40 ?m, and the porosity of the partition wall is 35 to 75%. The particles to be deposited have an average particle diameter of 1 to 15 ?m, and the height of the composite region is not more than 80 ?m in the direction from the outermost contour line of the partition walls to the surface of the partition walls.

Abstract: There is provided a honeycomb filter wherein particles having an average particle diameter smaller that of the particles constituting partition walls are deposited at least in open pores formed by the particles constituting the partition walls and/or gaps between the particles in a surface layer portion of the partition walls on the exhaust gas inflow side, thereby forming a composite region. The average pore diameter of the partition walls is 5 to 40 ?m, and the porosity of the partition wall is 35 to 75%. The particles to be deposited have an average particle diameter of 1 to 15 ?m, and the height of the composite region is not more than 80 ?m in the direction from the outermost contour line of the partition walls to the surface of the partition walls.

Abstract: A ceramic honeycomb filter comprising a honeycomb structure having large numbers of flow paths partitioned by porous cell walls, and plugs alternately formed in the flow paths on the exhaust-gas-inlet and outlet sides, the outlet-side plugs having porosity of 65% or less, and the upstream-side end surfaces of the outlet-side plugs having surface roughness Ra of 13-50 ?m.

Abstract: Disclosed is a particulate filter 10, which comprises a filter body 8 including a plurality of filter segments F1, F2 joined to each other by a joining material 7, wherein each of the filter segments includes a plurality of inflow cells each having a closed end on a downstream side in an exhaust-gas flow direction, and a plurality of outflow cells each having a closed end on an upstream side in the exhaust-gas flow direction. The filter segments include a first filter segment located in a central region of the particulate filter and designed to form each of the inflow cells to have an opening area approximately equal to that of each of the outflow cells, and a second filer segment located in at least a part of an outer peripheral region of the particulate filter and designed to form each of the inflow cells to have an opening area greater than that of each of the outflow cells.

Abstract: There is provided a honeycomb structure where a catalyst is loaded on surfaces of inner pores of the surface layer and on a surface of the surface layer; a relation between a catalyst area proportion A of the catalyst to a gap area proportion B of a gap in a cross-section of the surface layer on the inlet side is 1%<A/B<90%; and a relation between an average catalyst area proportion, A1, from the surface to a point having a depth of one third of the thickness of the surface layer including the surface of the surface layer on the inlet side and a catalyst area proportion A2 in a central portion of the surface layer is A1/A2>1.5.

Abstract: A ceramic honeycomb filter having improved thermal shock resistance is comprised of a ceramic honeycomb filter that has a heat absorbing material that undergoes a reversible phase change that absorbs at least in part the heat energy, for example, arising from the combustion of Diesel soot entrapped in the filter.

Abstract: There is provided a bonding material composition capable of suppressing crack generation on an end face of a resultant honeycomb structure to a large extent by reducing anisotropy of Young's modulus after curing of the bonding material by the use of an isotropic filler without using inorganic fibers. The bonded body has two or more members unitarily bonded by means of a bonding material layer, and the relational expression of 0.5<Ez/Ex<1.5 is satisfied when a Young's modulus in a direction perpendicular to a bonded surface of the bonding material layer is Ez and a Young's modulus in a direction parallel to the bonded surface and parallel to a longer axial direction of the bonded surface is Ex and wherein the bonded material has a porosity of 25 to 85%.

Abstract: A honeycomb filter includes cell walls and cells. The cell walls extend along a longitudinal direction of the honeycomb filter to define the cells between the cell walls. The cells have first cells and second cells each having a substantially square shape in a cross-section perpendicular to the longitudinal direction. The first cells are sealed and the second cells are open at one end face of the honeycomb filter. The substantially square shape of the first cells includes a first side whose extended line intersects a second side except for corner portions of the substantially square shape of the second cells. The second side and the extended line of the first side are substantially perpendicular.

Abstract: A system includes a particulate matter (PM) filter including an upstream end for receiving exhaust gas and a downstream end. A radiant zoned heater includes N zones, where N is an integer greater than one, wherein each of the N zones includes M sub-zones, where M is an integer greater than or equal to one. A control module selectively activates at least a selected one of the N zones to initiate regeneration in downstream portions of the PM filter from the one of the N zones, restricts exhaust gas flow in a portion of the PM filter that corresponds to the selected one of the N zones, and deactivates non-selected ones of the N zones.

Abstract: A honeycomb body, in particular for use in the exhaust system of a motor vehicle, includes an at least partially ceramic honeycomb structure through which a fluid can flow. The honeycomb structure is disposed in a tubular casing and has cavities. The honeycomb body has at least two axial subregions in a longitudinal direction. The honeycomb structure is connected to the tubular casing in an axial securing region and an axial measurement sensor region has a recess for accommodating a measurement sensor in the honeycomb structure. The honeycomb body has a permanent connection between the tubular casing and the ceramic honeycomb structure due to its preferably force-locking and/or form-locking connection between the tubular casing and the honeycomb structure in the securing region. Despite the recess, further damage to the honeycomb structure in the measurement sensor region is avoided. A process for producing such a honeycomb body is also provided.

Abstract: A honeycomb filter includes an outer wall having a substantially cylindrical shape and a central axis of the substantially cylindrical shape, first walls provided at an inner side of the outer wall and extending along the central axis, and second walls provided at the inner side of the outer wall and extending along the central axis. The first walls and the second walls substantially perpendicularly cross to define cells having a substantially square shape in a cross-section perpendicular to the central axis. A thickness of the outer wall in the cross-section at a first intersection between the outer wall and a first diameter substantially parallel to the first walls in the cross-section and a thickness of the outer wall in the cross-section at a second intersection between the outer wall and a second diameter substantially parallel to the second walls in the cross-section are largest.

Abstract: An assembled honeycomb structure includes at least two prismatic honeycomb segments. An outer cross section of each of the at least two prismatic honeycomb segments perpendicular to a flow direction in an interior of the assembled honeycomb structure is a quadrangle with included angles of one of: (i) about 60° and about 120°, or (ii) about 60°, about 90° and about 120°.

Abstract: A ceramic filter element of ceramic material has an exterior surface that is provided with structural elements. The structural elements are produced by a non-cutting method. The structural elements are molded in the ceramic material in the form of grids, periodic patterns, irregular patterns, lettering or labels.

Abstract: According to one representative embodiment, an exhaust aftertreatment component that includes a housing that defines an interior cavity through which exhaust gas is flowable. The housing includes an inner body, an outer body, and a space defined between the inner and outer bodies. The component also includes an insulation pack that is positioned within the space. The insulation pack includes insulation media encapsulated by a flexible fabric. The insulation pack further includes an at least partially rigid member that has a rigidity greater than a rigidity of the insulation media and flexible fabric.

Abstract: A bypass flow filter includes a plurality of channels which are formed of at least one structured wall layer and a filter layer. Projecting guide vanes and passages, which are formed by the wall layer and lead to a different channel, are provided in at least a majority of the channels. The passages have a narrowing cross section and a narrowing part of the cross section is directed towards an adjacent guide vane. An exhaust system and a vehicle having a bypass flow filter, are also provided.

Abstract: A method for selecting a filtering structure for a gas laden with particulates, said structure comprising a filtering part formed from a porous ceramic material and comprising at least one, and preferably a plurality, of porous walls, said method being characterized in that, starting from a first image of the surface of the wall, a processing operation is carried out on said first image comprising a morphological erosion by a structuring element in such a manner as to obtain a second characteristic image of the regularity and of the uniformity of the microstructure of said wall. Silicon carbide filtering structure obtained by application of said method.

Abstract: The present disclosure refers to a method for regenerating a filter adapted to remove particulate material from a gas. The disclosed method comprises at least producing at least one electric arc discharge pulse, the at least one electric arc discharge pulse being adapted to generate at least one pressure wave so that the particulate material is being dislodged from the filter. In addition, the disclosure refers to a filter regenerating arrangement and a diesel particulate filter.

Abstract: In a method for producing a ceramic filter element for an exhaust gas filter for an internal combustion engine or a catalyst support, a combustible non-ceramic support web is used and holes or recesses are introduced into the non-ceramic support web at defined locations.

Abstract: A highly porous substrate is provided using an extrusion system. More particularly, the present invention enables the production of a highly porous substrate. Depending on the particular mixture, the present invention enables substrate porosities of about 60% to about 90%, and enables advantages at other porosities, as well. The extrusion system enables the use of a wide variety of fibers and additives, and is adaptable to a wide variety of operating environments and applications. Fibers, which have an aspect ratio greater than 1, are selected according to substrate requirements, and are typically mixed with binders, pore-formers, extrusion aids, and fluid to form a homogeneous extrudable mass. The homogeneous mass is extruded into a green substrate. The more volatile material is preferentially removed from the green substrate, which allows the fibers to form interconnected networks.

Abstract: A carrier for exhaust-gas purification is able to effectively protect against getting clogged with the particulate matters in a filter having carriers. The carrier is constituted with a web corrugated to have straight and/or zigzag ridges and then wound up into a column. The carrier for exhaust-gas purification is made of the web of wire netting or nonwoven metallic fabric, which is embossed to have ridges and grooves extending at least in a widthwise direction and further wound up spirally or stacked on top of the other into the column.

Abstract: A system comprises a particulate matter (PM) filter that comprises an upstream end for receiving exhaust gas and a downstream end. A zoned heater is arranged spaced from the upstream end and comprises N zones, where N is an integer greater than one, wherein each of the N zones comprises M sub-zones, where M is an integer greater than one. A control module selectively activates at least a selected one of the N zones to initiate regeneration in downstream portions of the PM filter from the one of the N zones and deactivates non-selected ones of the N zones.

Abstract: A honeycomb structure 1 comprising a honeycomb segment bonded body 10 having a number of honeycomb segments 2 integrated on each bonding planes via bonding material layers 9 has a structure so that a number of cells 5 providing fluid flow channels are disposed in parallel in the direction of center axis thereof. The honeycomb structure 1 is constructed so that the porosity of an outer portion of the bonding material layers 9 (an area from the interface with the honeycomb segment-bonding plane to a point apart from that interface by a distance equivalent to 20% of the entire layer thickness) is smaller than the porosity of a central portion located inward of the outer portion, and so that the bonding material layers 9 have a compression Young's modulus along the Z-axis of 5 to 100 MPa.

Abstract: A honeycomb structure includes a ceramic block, a coating layer and at least one of the bonding layer and the coating layer. The ceramic block includes a plurality of honeycomb units that are bonded together and that have a plurality of cells partitioned by cell walls using a bonding layer. The coating layer is provided on an outer peripheral portion of the ceramic block. The at least one of the bonding layer and the coating layer includes bubble marks having a diameter in a range of approximately 100 ?m to approximately 300 ?m and includes no bubble marks having a size exceeding approximately 300 ?m.