Patent Description:
The disclosure relates to honeycomb bodies, and more particularly to porous ceramic honeycomb bodies such as for particulate filters suitable for filtering particles from a fluid stream, such as engine exhaust, and non-claimed extrusion dies therefor.

Honeycomb particulate filters typically include a honeycomb body having a plurality of intersecting porous ceramic walls forming axially-extending channels of the same cross-sectional area. Half of these channels are plugged on the inlet side in a checkerboard pattern with these same channels being unplugged on the outlet side, thus forming outlet channels. The other half of the axially-extending channels are plugged in a checkerboard pattern on the outlet side and unplugged on the inlet side, thus forming inlet channels. In use, engine exhaust flows through the porous ceramic walls of the honeycomb body and particles (soot and other inorganic particles) are filtered from the engine exhaust stream. Examples of a honeycomb are disclosed in <CIT> and <CIT>.

Some honeycomb filter configurations have included a modification of the honeycomb structure of the honeycomb body to include inlet channels having larger cross-sectional area than the outlet channels (i.e., higher inlet open frontal area). Relatively-larger inlet channels have effectively reduced the severity of pressure drop increases as soot and ash loading increase over time. However, making larger and larger inlet cells (and/or smaller and smaller outlet cells) may cause the honeycomb structures to become relatively expensive to manufacture, and may lead to other performance limitations. Accordingly, honeycomb body designs having relatively high soot and ash carrying capability, improved pressure drop performance, and inexpensive manufacture are sought.

In one aspect, a honeycomb body as defined in claim <NUM> is provided.

In an embodiment, the honeycomb body of claim <NUM> comprises intersecting porous walls in a matrix comprising a pattern of repeating structural units. The repeating structural units have <NUM> inch (<NUM>) ≤ Tw ≤ <NUM> inch (<NUM>), <NUM>% ≤ %P ≤ <NUM>%, <NUM> microns ≤ MPS ≤ <NUM> microns, and <NUM>% ≤ inlet OFA ≤ <NUM>%, wherein each of the repeating structural units comprises a first cell, a second cell, a third cell, and a fourth cell. The cells extend parallel to each other in an axial direction from an inlet face to an outlet face and have a quadrilateral cross-section in a transverse plane orthogonal to the axial direction. The cells are plugged to define inlet channels and outlet channels within the repeating structural unit, wherein each of the repeating structural units comprises a first channel formed from the first cell comprising, in transverse cross-section, a length L<NUM>, a width W<NUM>, and a cross-sectional area A<NUM>, the first channel having a first sidewall and a second sidewall orthogonal to the first sidewall, a second channel formed from the second cell and comprising, in cross-section, a length L<NUM>, the width W<NUM>, and a cross-sectional area A<NUM>, and sharing the second sidewall with the first channel, a third channel formed from the third cell comprising, in cross-section, the length L<NUM>, a width W<NUM>, and a cross-sectional area A<NUM>, and comprising a third sidewall and sharing the first sidewall with the first channel, and a fourth channel formed from the fourth cell and comprising, in cross-section, the length L<NUM>, the width W<NUM>, and a cross-sectional area A<NUM>, and sharing a fourth sidewall with the second channel and the third sidewall with the third channel. The first, second, and third channels comprise inlet channels and the fourth channel comprises an outlet channel having a rectangular shape in transverse cross-section, wherein at least one of W<NUM> ≥ W<NUM> and L<NUM>≠L<NUM>, and the repeating structural unit comprises a quadrilateral outer perimeter. Tw is a transverse wall thickness, %P is an open porosity of the porous walls, MPS is a median pore size (D50), and inlet OFA is an inlet open area of the honeycomb body.

Numerous other features and aspects are provided in accordance with these and other embodiments of the disclosure. Further features and aspects of embodiments will become more fully apparent from the following detailed description, the appended claims, and the accompanying drawings.

The accompanying drawings, described below, are for illustrative purposes and are not necessarily drawn to scale. The drawings are not intended to limit the scope of the disclosure in any way. Like numerals are used throughout the specification and drawings to denote like elements.

Reference will now be made in detail to the example embodiments of this disclosure, which are illustrated in the accompanying drawings. In describing the embodiments, numerous specific details are set forth in order to provide a thorough understanding of the disclosure. However, it will be apparent to one skilled in the art that the invention may be practiced without some or all of these specific details. In other instances, well-known features and/or process steps have not been described in detail so as not to unnecessarily obscure the invention. Features of the various embodiments described herein may be combined with each other, unless specifically noted otherwise.

In various embodiments, the present disclosure relates to honeycomb bodies that can be configured for use as a wall-flow filter comprised of a plugged honeycomb structure body, such as a Gasoline Particulate Filter (GPF) or a Diesel Particulate Filter (DPF). In various embodiments, filters disclosed herein preferably can provide excellent storage capacity of soot and/or ash or other inorganic particles in the honeycomb body relative to currently-available particulate filter designs, and further preferably does so while maintaining relatively-low clean pressure drop and relatively-low pressure drop increase across the filter as a function of soot and/or ash loading.

A particulate filter (e.g. GPF or DPF) collects soot particles and ash and can trap inorganic materials that may be present in the soot or that may flake off from engine or exhaust components, such as a manifold. Inorganic materials typically do not burn out along with the soot via regeneration, and therefore inorganic matter could build up with the ash over time within the particulate filter. Such build up may eventually result in a pressure drop increase across the honeycomb body, which may be unacceptably high. To alleviate this pressure increase, maintenance of the particulate filter may be undertaken via removal and replacement with a new filter or cleaned filter that has had ash and inorganic material removed, leading to more costs.

Thus, in accordance with one or more embodiments of the present disclosure, a honeycomb body is provided with high ash/inorganic storage capacity to provide for longer times between service intervals, and which preferably limits a pressure drop increase penalty as a function of soot and/or ash loading. Moreover, one or more embodiments of the present disclosure may provide manufacturing benefits because relatively inexpensive existing extrusion die manufacturing technologies could be utilized. For example, in one or more embodiments, straight line die cuts from side-to-side entirely across the extrusion die outlet face (e.g., in a single direction, or even in two orthogonal directions) may be used. For example, relatively inexpensive cutting wheels and/or wire electron discharge machining (wire EDM) die manufacturing technologies may be used, which may dramatically lower die cost compared to other techniques such as plunge EDM or ECM. Moreover, one or more embodiments may benefit from improved structural rigidity of the honeycomb body, in the green state and/or in the fired state.

One or more embodiments of the honeycomb body comprise intersecting porous walls in a matrix comprising a pattern of repeating structural units. Each of the repeating structural units comprises a first cell, a second cell, a third cell, and a fourth cell, wherein the cells all extend parallel to each other in an axial direction from an inlet face to an outlet face. Each cell has a quadrilateral shape in cross-section in a transverse plane orthogonal to the axial direction (hereinafter "transverse cross-section"). The respective cells of the repeating structural units are plugged to define inlet channels and outlet channels therein. Each of the repeating structural units comprises a first channel formed from the first cell comprising, in transverse cross-section, a length L<NUM>, a width W<NUM>, and a cross-sectional area A<NUM>, the first channel comprising a first sidewall and a second sidewall orthogonal to the first side wall. Each of the repeating structural units comprises a second channel formed from the second cell and comprising, in transverse cross-section, a length L<NUM>, the width W<NUM>, and a cross-sectional area A<NUM>, and sharing the second sidewall with the first channel. A third channel of each of the "repeating structural units" is formed from the third cell and comprises, in transverse cross-section, the length L<NUM>, a width W<NUM>, and a cross-sectional area A<NUM>, comprising a third sidewall and sharing first sidewall with the first channel. A fourth channel of each of the "repeating structural units" is formed from the fourth cell and comprises, in transverse cross-section, the length L<NUM>, the width W<NUM>, and a cross-sectional area A<NUM>, and sharing a fourth sidewall with the second channel and the third sidewall with the third channel. The first channel, the second channel, and the third channel comprise inlet channels and the fourth channel comprises an outlet channel with a rectangular shape, wherein a first two sides are of equal length and second two sides are of equal length and which have a length different than the length of the first two sides, in transverse cross-section, and wherein at least one of W<NUM>≥W<NUM> and L<NUM>≠L<NUM>, and the repeating structural unit comprises a quadrilateral outer perimeter. In some embodiments, W<NUM>>W<NUM> and L<NUM>=L<NUM>. In other embodiments, W<NUM>>W<NUM> and L<NUM>≠L<NUM>. In yet other embodiments, W<NUM>>W<NUM> and <NUM> ≤ L<NUM>/L<NUM> ≤ <NUM>, for example. Other combinations of W<NUM>, W<NUM>, L<NUM>, and L2 are possible.

Other structural and microstructural attributes of embodiments of the repeating structural unit providing one or more of the afore-mentioned performance benefits are described fully herein.

As used herein "honeycomb body" means a wall-flow honeycomb body configured to be accepted into and used in a can or housing, comprising open and interconnected porosity, a matrix of intersecting cell walls, and comprising at least some plugged inlet channels and at least some plugged outlet channels.

In other embodiments of the disclosure, particulate filters comprising the honeycomb bodies, exhaust systems comprising particulate filters, extrusion dies for manufacturing the inventive honeycomb bodies, as well as methods of filtering particulates and manufacturing the honeycomb bodies are provided, as are other aspects and features.

Further details of example honeycomb bodies, particulate filters, exhaust systems comprising particulate filters, extrusion dies for manufacturing the honeycomb bodies described herein, and methods of filtering particulates and manufacturing of the honeycomb bodies are described with reference to <FIG> herein.

<FIG> illustrates various views, respectively, of a first example embodiment of a honeycomb body <NUM> according to the present disclosure. The honeycomb body <NUM> is has utility for use as a filtering media in a particulate filter, which is used for filtering particulates (e.g., soot and/or inorganics) from a flow stream such as from an engine exhaust stream of an internal combustion engine (e.g., gas or diesel engine). The honeycomb body <NUM> comprises porous walls <NUM> that intersect with one another (e.g., at right angles) and form a plurality of longitudinally-extending cells that are parallel with one another. The porous walls <NUM> may comprise open, interconnected porosity and the porous walls <NUM> may be made of a ceramic or other suitable porous material that can withstand high temperatures in use, such as those encountered during thermal regeneration of the honeycomb body <NUM>. For example, the intersecting porous walls <NUM> may be made of a ceramic material, such as cordierite, silicon carbide (SiC), aluminum titanate, mullite, alumina (Al<NUM>O<NUM>), silicon aluminum oxynitride (Al<NUM>O<NUM>N<NUM>Si), mullite, zeolite, combinations of the afore-mentioned, and the like. Other suitable porous materials may be used, such as fused silica or porous metal, or combinations thereof.

In the case of ceramics, walls <NUM> may be formed during an extrusion process wherein a suitable batch mixture (such as inorganic and organic batch components and a liquid vehicle such as water) are extruded through a honeycomb extrusion die and then dried and further fired to produce a porous ceramic honeycomb body (without plugs). The ceramic honeycomb body may then be plugged in a defined plugging pattern described herein to produce the honeycomb bodies <NUM>. Plugging may be accomplished as described in <CIT>et al or by other methods. In some embodiments, the dried green honeycomb body may be plugged and then fired, or alternatively partially fired, plugged, and fired again. Various microstructural attributes of the material of the porous walls <NUM> are described herein.

The honeycomb body <NUM> may comprise a skin <NUM> (<FIG>) on an outer radial periphery defining an outer peripheral surface <NUM> of the honeycomb body <NUM>. The skin <NUM> may be extruded along with extrusion of the honeycomb matrix structure or may be applied to the honeycomb body post-extrusion (post-drying, or post-firing), for example in some embodiments an after-applied skin applied as ceramic-based skin cement onto an outer periphery (e.g., machined periphery) of a ceramic or dried green body honeycomb body. The skin <NUM> may comprise a skin thickness Ts (<FIG>) that is substantially uniform about the radial periphery of the honeycomb body <NUM>, for example. The skin thickness Ts may be between about <NUM> to <NUM>, or even between <NUM> to <NUM>, for example. Other skin thicknesses Ts may be used. Apparatus and methods for skinning articles, such as honeycomb bodies are described in <CIT>, for example. Other suitable skinning methods may be used. In some embodiments described herein, the intersecting porous walls <NUM> may advantageously extend continuously across the honeycomb body <NUM> between sections of the skin <NUM>, such as to obtain benefits in terms of reducing extrusion die cost. In other embodiments, the matrix of cell walls comprises one or more configurations within the same honeycomb body.

The outermost cross-sectional shape of the honeycomb body <NUM> may be a circle, an ellipse, an oval, or a racetrack shape, but the honeycomb body <NUM> is not limited to these cross-sectional shapes. Other cross-sectional shapes may be used, such as triangular or tri-lobed, square, or rectangular shapes.

The repeating structural unit comprises a plurality of cells, comprising a first cell <NUM>, a second cell <NUM>, a third cell <NUM>, and a fourth cell <NUM>, wherein at least some of the cells have a different cross-sectional shape in transverse cross-section than the other cells of the repeating structural unit <NUM>. In some embodiments, the plurality of cells <NUM>-<NUM> may be constituted of two different types of cell shapes, in cross-section, such as combinations of different quadrilateral cell shapes, such as combinations of rectangular cell shapes and square cell shapes. "Rectangular" as used herein means a quadrilateral having four sides and <NUM> degree corners, wherein a first two sides are of equal length and second two sides are of equal length, and which have a length different than the length of the first two sides. "Quadrilateral" as used herein means a four-sided polygon having four and only four straight sides. In other embodiments, the plurality of cells <NUM>-<NUM> may be constituted of four different types of cell shapes, in transverse cross-section, such as combinations of different-sized rectangular cells. All of the first cell <NUM>, second cell <NUM>, third cell <NUM>, and fourth cell <NUM> may extend parallel to one another along an axial axis <NUM> from an inlet face <NUM> to an outlet face <NUM>, wherein the inlet face <NUM> and outlet face <NUM> are generally opposed to one another as shown in <FIG>. The transverse cross-sectional area of each cell <NUM>-<NUM> may be constant along its length. Moreover, the transverse wall thickness Tw of the porous walls <NUM> may be constant along a length of the porous walls <NUM>.

In one or more embodiments, the first cell <NUM>, second cell <NUM>, third cell <NUM>, and fourth cell <NUM> are plugged in a plugging pattern <NUM> and the surfaces of the plugs and the cells <NUM>-<NUM> together define inlet channels <NUM> and outlet channels <NUM>. Some of the cells <NUM>, <NUM>, <NUM>, <NUM> are plugged at or near the outlet face <NUM>, but are unplugged at or near the inlet face <NUM> and are defined herein as inlet channels <NUM>. Others of the cells <NUM>, <NUM>, <NUM>, <NUM> are plugged at or near the inlet face <NUM>, but are unplugged at or near the outlet face <NUM> and are defined herein as outlet channels <NUM>. In the depicted embodiment, all of the cells <NUM>, <NUM>, <NUM>, <NUM> of the repeating structural unit <NUM> may be plugged at least at or near one end, i.e., none are unplugged. However, in some embodiments, certain ones of the cells may be intentionally left unplugged along a length thereof, so as to provide one or more flow through channels in the honeycomb body.

In embodiments, the number of inlet channels <NUM> may be greater than the number of outlet channels <NUM> in the honeycomb body <NUM> and in the repeating structural unit <NUM>. In embodiments, a number of inlet channels <NUM> may be three times the number of outlet channels <NUM>. The plugs <NUM> of the plugging pattern <NUM> may be formed from a suitable plugging material such as a ceramic plug material, comprising cordierite, aluminum titanate, mullite, silicon carbide, and/or other materials that can withstand high temperatures, such as those encountered during thermal regeneration of the honeycomb body <NUM>. Suitable powdered inorganic material(s) may be mixed with an organic binder and liquid vehicle, for example, to produce the plugging material. Suitable non-limiting plugging materials and processes are described in <CIT>, <CIT>, <CIT>, and <CIT>, for example. The plugs <NUM> may or may not be flush with the inlet face <NUM> and outlet face <NUM>. Plugs <NUM> may fill the channel width and height and may have a plug depth along the axial axis <NUM> of between about <NUM> inch (<NUM>) and about <NUM> inch (<NUM>), or even between about <NUM> inch (<NUM>) and about <NUM> inch (<NUM>), for example. Other plug depths may be used. The plugs <NUM> may comprise open interconnected porosity.

Referring now to <FIG> and <FIG>, a honeycomb body <NUM> comprising a repeating structural unit <NUM> that is repeated throughout the honeycomb body <NUM> is shown. Repeating structural unit <NUM> as used herein means a collection of three of the inlet channels <NUM> and a single one of the outlet channels <NUM> that is arranged in a specific pattern that is repeated over and over to form at least some of the structure of the honeycomb body <NUM>. As shown in this embodiment, each repeating structural unit <NUM>, as viewed from the inlet face <NUM>, consists of one of the outlet channels <NUM> and three of the inlet channels <NUM>, and has a quadrilateral outer perimeter shape (e.g., the outer shape of the repeating structural unit <NUM> is rectangular). The repeating structural unit <NUM> comprises the configuration as is shown in <FIG>, as well as its mirror image.

In some embodiments, each repeating structural unit <NUM> is provided in a direct abutting relationship with other adjacent repeating structural units <NUM>' (one labeled in <FIG>) that are substantially identical to the repeating structural unit <NUM>. In some regions of the inlet face <NUM>, the repeating structural unit <NUM> may be entirely surrounded and abutted by other adjacent repeating structural units <NUM>' that are substantially identical to the repeating structural unit <NUM>. As depicted in <FIG>, each side of the repeating structural unit <NUM> may be directly abutted by an adjacent repeating structural unit <NUM>'. Some of the repeating structural units <NUM> near the skin <NUM> may be adjacent to one or more incomplete repeating structural units (including less than all the structure of a repeating structural unit <NUM>). As will be apparent, in other embodiments, other configurations of cells and channels and other types of repeating structural units may be present in the honeycomb body along with the repeating structural units <NUM>.

In one or more embodiments, the repeating structural unit <NUM> is made up of a first channel <NUM>, a second channel <NUM>, a third channel <NUM>, and a fourth channel <NUM> that are arranged in a defined pattern, wherein each one of the channels <NUM>-<NUM> may be provided in a directly abutting relationship with each of the other channels of the repeating structural unit <NUM> either at the sides or at a corner (e.g., diagonally) thereof. Referring now to <FIG>, the channels <NUM>-<NUM> of the repeating structural unit <NUM> may be rectangular in transverse cross-section. In the depicted embodiment, the outlet channel <NUM> is rectangular in transverse cross-sectional shape (e.g., the fourth channel <NUM>). The other channels <NUM>-<NUM> are inlet channels <NUM> and may also be rectangular in transverse cross-sectional shape. Other embodiments described herein may comprise one or more combinations of rectangular and square channels in transverse cross-sectional shape.

Thus it should be understood that in some embodiments, each of the channels <NUM>-<NUM> in the repeating structural unit <NUM> is rectangular. In other embodiments, the first channel <NUM> and the second channel <NUM> in the repeating structural unit are rectangular. In other embodiments, the first channel <NUM> and the second channel <NUM> in the repeating structural unit <NUM> are square. In some embodiments, the third channel <NUM> and the fourth channel <NUM> in the repeating structural unit <NUM> are rectangular. Each of the channels <NUM>-<NUM> of the embodiments described herein may comprise slight radii or a chamfer or bevel at one or more of the corners of the channels thereof.

Referring to <FIG>, the repeating structural unit <NUM> comprises the area of the four channels <NUM>-<NUM> and comprises half of the transverse wall thickness Tw of the porous walls <NUM> surrounding the outer perimeter of the cluster of channels <NUM>-<NUM>. In other words, the repeating structural unit <NUM> is equal to (L<NUM> + L<NUM> + 2Tw) x (W<NUM> + W<NUM> + 2Tw).

The repeating structural unit <NUM> has an outer perimeter shape that is a quadrilateral (e.g., rectangular or square) in transverse cross-section. The repeating structural unit <NUM> comprises the first channel <NUM>, which may be formed from the first cell <NUM>, and comprises, in transverse cross-section, a length L<NUM>, a width W<NUM>, and a cross-sectional area A<NUM>. The first channel <NUM> comprises a first sidewall <NUM> and a second sidewall <NUM> that may be orthogonal to the first sidewall <NUM>. In the depicted embodiment, the first channel <NUM> comprises an inlet channel <NUM> and comprises a rectangular cross-sectional shape in transverse cross-section, wherein L<NUM>>W<NUM>. However, as will be apparent, the first channel <NUM> may have a square cross-sectional shape in some embodiments (See <FIG> where W<NUM>=L<NUM>), or even a rectangular cross-section wherein W<NUM>>L<NUM>, or even L<NUM>>W<NUM>.

The second channel <NUM> of the repeating structural unit <NUM> may be formed from the second cell <NUM> and comprises, in transverse cross-section, a length L<NUM>, the width W<NUM>, and a second cross-sectional area A<NUM>. The second channel <NUM> shares the second sidewall <NUM> with the first channel <NUM>. In the depicted embodiment, the second channel <NUM> may comprise an inlet channel <NUM> and comprises a rectangular cross-sectional shape in transverse cross-section, wherein L<NUM>>W<NUM> and L<NUM>=L<NUM> and A<NUM>=A<NUM>. However, in some embodiments, the second channel <NUM> may have a square cross-sectional shape wherein W<NUM>=L<NUM> or even a rectangular cross-section wherein W<NUM>>L<NUM>, or even L<NUM>>W<NUM>.

The third channel <NUM> of the repeating structural unit <NUM> may be formed from the third cell <NUM> comprising, in transverse cross-section, the length L<NUM>, a width W<NUM>, and a cross-sectional area A<NUM>. The third channel <NUM> comprises a third sidewall <NUM> and shares the first sidewall <NUM> with the first channel <NUM>. In the depicted embodiment, the third channel <NUM> comprises an inlet channel <NUM> and may comprise a rectangular cross-sectional shape in transverse cross-section, wherein W<NUM>>L<NUM>.

The fourth channel <NUM> of the repeating structural unit <NUM> may be formed from the fourth cell <NUM> and comprises, in transverse cross-section, the length L<NUM>, the width W<NUM>, and a cross-sectional area A<NUM>. The fourth channel <NUM> shares a fourth sidewall <NUM> with the second channel <NUM> and the third sidewall <NUM> with the third channel <NUM>. In the depicted embodiment, the fourth channel <NUM> comprises an outlet channel <NUM> and comprises a rectangular cross-sectional shape, wherein a first two sides are of equal length and second two sides are of equal length and which have a length different than the length of the first two sides, in transverse cross-section, wherein W<NUM>>L<NUM> and A<NUM>=A<NUM>. However, in some embodiments, L<NUM>>L<NUM> and A<NUM>>A<NUM>. The structural and microstructural attributes of the repeating structural unit <NUM> will be described in more detail below.

In some embodiments disclosed herein, a honeycomb assembly 100A may be produced by adhering together multiple ones of honeycomb bodies 100B (e.g., having a square or rectangular outer perimeter) for example as is shown in <FIG>. Each of the honeycomb bodies 100B may comprise multiple ones of the repeating structural unit <NUM>, as described herein, repeated within the honeycomb bodies 100B. A suitable cement mixture may be used for adhering together the multiple sections of honeycomb bodies 100B. For example, a cement mixture such as is described in <CIT> may be used. The outer shape of the honeycomb assembly 100A shown in <FIG> is square. However, other outer peripheral shapes may be used, such as rectangular, circular, elliptical, oval, race track, and the like. A skin 103A may be applied around the outer periphery of the honeycomb assembly 100A.

<FIG> illustrate another embodiment of honeycomb body <NUM> that comprises the same repeating structural unit <NUM> as described with reference to <FIG>, i.e., that is repeated throughout at least a portion of the honeycomb body <NUM>, but the repeating structural unit <NUM> is oriented in a staggered configuration relative to some adjacent repeating structural units <NUM>' abutting therewith. For example, the pattern of repeating structural units comprises repeating structural units <NUM> disposed in a staggered configuration wherein the first channels <NUM> share a side wall with the fourth channels <NUM>. In particular, the repeating structural unit <NUM> is staggered so that no outlet channel (e.g., fourth channel <NUM>) of a directly-adjacent repeating structural unit <NUM>' is included in a same vertical column of outlet channels (vertical is as shown with the long dimensions of the third and fourth channels <NUM>, <NUM> aligned vertically). For example, as shown in <FIG>, a directly adjacent repeating structural unit <NUM>' is shown offset one column to the right from the repeating structural unit <NUM>. This staggered configuration of the repeating structural unit <NUM> has been unexpectedly found to provide performance benefits in terms of even lower pressure drop and improved filtration efficiency, and may have increased strength as compared to the stacked configuration. In this staggered configuration, two sides (e.g., left and right sides as depicted) of the repeating structural unit <NUM> may be abutted directly by one adjacent repeating structural unit <NUM>' all along the height thereof (e.g., the left and right sides as shown) and the other two sides (e.g., top and bottom sides, as shown) of the repeating structural unit <NUM> may each be abutted directly by portions of two adjacent repeating structural unit <NUM>' (e.g., two adjacent repeating structural units <NUM>' above and two below).

<FIG> illustrate additional embodiments, wherein only the repeating structural unit <NUM>, <NUM>, <NUM> of each embodiment is shown. The repeating structural units <NUM>, <NUM> may be repeated within the honeycomb structure in either a stacked orientation as shown in <FIG>, or in a staggered orientation as is shown in <FIG>. The embodiment of <FIG> may be provided in a stacked configuration. In the stacked configuration, the pattern of repeating structural units comprises repeating structural units <NUM> disposed in a stacked configuration wherein the first channel <NUM> does not share a side wall with a fourth channel <NUM>. The honeycomb body <NUM>, <NUM>, <NUM> comprising each of the repeating structural units <NUM>, <NUM>, <NUM>, respectively, is made up of repeating structural units that may abut directly with adjacent repeating structural units that are identical to the repeating structural units <NUM>, <NUM>, <NUM>. Directly abutting as used herein means that there are no intervening channels. The honeycomb bodies <NUM>, <NUM>, <NUM> in some embodiments are made up of only the repeating structural units <NUM>, <NUM>, <NUM> together with incomplete repeating structural units adjacent to a skin of the honeycomb bodies <NUM>, <NUM>, <NUM>. In other embodiments, honeycomb bodies <NUM>, <NUM>, <NUM> may be made up of some of the repeating structural units <NUM>, <NUM>, or <NUM> in combination with other types of repeating structural units or channels.

Referring now to <FIG>, the repeating structural unit <NUM> of the honeycomb body <NUM> comprises a first channel <NUM> and a second channel <NUM> that are inlet channels and comprise a same first shape, which is square in transverse cross-sectional shape. The third channel <NUM> and the fourth channel <NUM> each comprise a second shape, which is rectangular in transverse cross-sectional shape. The fourth channel <NUM> is an outlet channel, while the other channels <NUM>, <NUM>, <NUM> are inlet channels. In particular, in this embodiment, A<NUM>=A<NUM>>A<NUM>=A<NUM>. Also, in this embodiment, L<NUM>=L<NUM>=W<NUM> and W<NUM><W<NUM>. The repeating structural unit <NUM> may be arranged in the honeycomb body <NUM> in either a stacked configuration as shown in <FIG> or in a staggered configuration like is shown in <FIG>. As will be apparent, the combined shapes and geometrical dimensions of the repeating structural unit <NUM> provides performance of the honeycomb body <NUM> that exhibits low clean pressure drop, as well as low pressure drop increase as a function of soot loading, both in the clean state and/or soot or ash-loaded state. Particular structural dimensions and other features and properties of embodiments of the repeating structural unit <NUM> are described below.

For example, Table <NUM> below illustrates the performance of several example embodiments (Ex. <NUM>-<NUM>, and <NUM>-<NUM>) of honeycomb bodies <NUM> comprising the configuration of repeating structural unit <NUM> shown in <FIG> and which are provided in a staggered configuration (Like <FIG>). Furthermore, <FIG> illustrate pressure drop performance across an example embodiment of a honeycomb body <NUM> comprising the repeating structural unit <NUM> in a staggered configuration shown plotted with comparative examples (e.g., Comp. <NUM>-<NUM>).

The pressure drop performance plots of inventive example <NUM> (Inventive Ex. <NUM>), including no ash, i.e., including various soot loadings (from <NUM>-<NUM>/L) in <FIG> illustrate that the no ash, soot-loaded pressure drop performance of this particular configuration of honeycomb body <NUM> comprising staggered repeating structural units <NUM> is substantially better than either of comparative Ex. <NUM>, or Ex. <NUM>, wherein comparative example <NUM> (Comp Ex. <NUM>) is an ACT design, comparative example <NUM> (Comp. <NUM>) is a standard design with checkerboard plugging, and comparative example <NUM> (Comp. <NUM>) is a high inlet number design. Comparative examples <NUM>-<NUM> are disclosed in Table <NUM> below. Not only is the absolute magnitude of the pressure drop lower for all soot-loaded conditions for inventive Ex. <NUM>, including clean pressure drop, but the rate of change of an increase in pressure drop (i.e., the slope of pressure drop/soot load) as a function of soot loading is also lower.

<FIG> illustrates that the soot-loaded pressure drop on an ash-loaded (e.g., <NUM>/L ash) honeycomb body <NUM> of the Inventive Ex. <NUM> comprising the staggered repeating structural unit <NUM> is also substantially lower than the comparative examples (Comp. <NUM>-<NUM>). Moreover, the slope, i.e., rate of change of the pressure drop is also lower as the soot loading increases from <NUM>/L to <NUM>/L of soot when compared to at least comparative Ex. <NUM> and <NUM>.

The configuration and properties of Comp. <NUM>-<NUM> are shown in Table <NUM> below. Comparative Ex. <NUM> has a honeycomb body structure shown and described in <FIG> of <CIT>, i.e., a channel structure known as asymmetric cell technology (ACT) wherein the inlet channels are larger in area than the outlet channels. Comparative Ex. <NUM> is a standard honeycomb body structure with inlet channels of the same cross-sectional size and number as the outlet channels, such as in shown in <FIG> of <CIT>. Comparative Ex. <NUM> has an increased inlet number channel structure shown and described in <FIG> of <CIT>, i.e., a honeycomb body structure comprising a repeating structural unit having all square channels and more inlet channels than outlet channels.

Referring now to <FIG>, another embodiment of honeycomb body <NUM> is shown. The repeating structural unit <NUM> is shown in isolation in <FIG>. However, the repeating structural unit <NUM> may be arranged in either a stacked or a staggered configuration, as is shown in <FIG> and <FIG>, within the honeycomb body <NUM>. The repeating structural unit <NUM> of the honeycomb body <NUM> comprises a first channel <NUM> and a second channel <NUM> that are both inlets and are rectangular, in cross-sectional shape in transverse cross-section. The third channel <NUM> and the fourth channel <NUM> are also rectangular in cross-sectional shape in transverse cross-section, and are of the same cross-sectional shape and area. The fourth channel <NUM> is an outlet channel, wherein the first channel <NUM>, second channel <NUM>, and third channel <NUM> are inlet channels.

In particular, in some embodiments of <FIG>, A<NUM>=A<NUM>>A<NUM>=A<NUM>. Also, in such embodiments, L<NUM>=L<NUM>, W<NUM>>W<NUM>, W<NUM>>L<NUM>, and W<NUM>>L<NUM>. As will be apparent, these combined shapes and dimensions of the repeating structural unit <NUM> also provides performance of the honeycomb body <NUM> that exhibits excellent clean pressure drop as well as low pressure drop increase as a function of soot and/or ash loading. Particular structural dimensions and features of the repeating structural unit <NUM> are described below. In similar embodiments of <FIG>, L<NUM>=L<NUM>, and W<NUM>>W<NUM>, but W<NUM><L<NUM>, and W<NUM><L<NUM> are provided. In further optional embodiments, the repeating structural unit <NUM> may comprise L<NUM>=L<NUM> and W<NUM>=W2, but wherein W<NUM>>L<NUM> or W<NUM><L<NUM>. <NUM> has all rectangles and L<NUM>=L<NUM> and W<NUM>=W<NUM>.

<FIG> illustrates another embodiment of honeycomb body <NUM>. The repeating structural unit <NUM> is also shown in isolation in <FIG>. In this embodiment, the repeating structural unit <NUM> may be arranged in either a stacked configuration, as shown in <FIG>, within the honeycomb body <NUM>. The repeating structural unit <NUM> of the honeycomb body <NUM> comprises a first channel <NUM> and a second channel <NUM> that are both rectangular in cross-sectional shape in transverse cross-section. However, in some embodiments, first channel <NUM> and a second channel <NUM> may have a square shape in transverse cross-section. The third channel <NUM> and the fourth channel <NUM> are rectangular in cross-sectional shape in transverse cross-section. The fourth channel <NUM> is an outlet channel, wherein the first channel <NUM>, second channel <NUM>, and third channel <NUM> are inlet channels. In particular, in this embodiment of <FIG>, A<NUM>>A<NUM>>A<NUM>>A<NUM>. Also, in this embodiment, L<NUM>≠L<NUM>, W<NUM>>W<NUM>, W<NUM>>L<NUM>, W<NUM>>L<NUM>, W<NUM>>L<NUM>, and W<NUM>>L<NUM>. As will be apparent, the combined shapes and dimensions of the repeating structural unit <NUM> also provide for improved performance of the honeycomb body <NUM> such that it exhibits excellent clean pressure drop as well as low pressure drop increase as a function of soot and/or ash loading. Particular dimensions and features of example structures of the repeating structural unit <NUM> are described below. Optionally, in some embodiments, L<NUM>≠L<NUM>, W<NUM>>W<NUM>, W<NUM>>L<NUM>, and W<NUM>>L<NUM>, but wherein W<NUM><L<NUM>, and W<NUM><L<NUM>.

Each of the embodiments of <FIG>, <FIG>, and <FIG> may comprise certain microstructural and geometrical structural properties, which in combination with the configuration of the repeating structural unit <NUM>, <NUM>, <NUM>, <NUM> may provide for a combination of good soot and ash loading capacity and relatively-low pressure drop performance, including relatively-low clean pressure drop as well as relatively-low pressure drop increase as a function of soot and/or ash loading. For example, the open and interconnected porosity (% P) of the porous walls <NUM>, after firing, may be %P ≥ <NUM>%, %P ≥ <NUM>%, %P ≥ <NUM>%, %P ≥ <NUM>%, or even %P ≥ <NUM>% in some embodiments. In some embodiments, the open and interconnected porosity of the intersecting porous walls <NUM> may be <NUM>% ≤ %P ≤ <NUM>%, or even <NUM>% ≤ %P ≤ <NUM>%, or even <NUM>% ≤ %P ≤ <NUM>%. Other values of %P may be used. Porosity (%P) as recited herein is measured by a mercury porosity measurement method. The honeycomb bodies <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> of each of the embodiments of <FIG>, <FIG>, and <FIG> may comprise an inlet open frontal area (inlet OFA) of <NUM>% ≤ inlet OFA ≤ <NUM>%, or even <NUM>% ≤ inlet OFA ≤ <NUM>%.

The porous walls <NUM>, after firing, may comprise a transverse wall thickness Tw of Tw ≥ <NUM> inch (<NUM>), Tw ≥ <NUM> inch (<NUM>), Tw ≥ <NUM> inch (<NUM>), or even Tw ≥ <NUM> inch (<NUM>) in some embodiments. In some embodiments, Tw ≤ <NUM> inch (<NUM>), Tw ≤ <NUM> inch (<NUM>), or even Tw ≤ <NUM> inch (<NUM>). In one or more embodiments, <NUM> inch (<NUM>) ≤ Tw ≤ <NUM> inch (<NUM>), or even <NUM> inch (<NUM>) ≤ Tw ≤ <NUM> inch (<NUM>), for example. Other values of transverse wall thickness Tw may be used.

The porous walls <NUM>, after firing, may comprise a median pore diameter (MPD) of <NUM> ≤ MPD ≤ <NUM>, or even <NUM> ≤ MPD ≤ <NUM> in some embodiments. The breadth Db of the pore size distribution of the open, interconnected porosity may be Db ≤ <NUM>, or even Db ≤ <NUM>, wherein Db = ((D<NUM>-D<NUM>)/D<NUM>), wherein D<NUM> is an equivalent spherical diameter in the pore size distribution of the porous walls <NUM> where <NUM>% of the pores have an equal or smaller diameter and <NUM>% have a larger diameter, and D<NUM> is an equivalent spherical diameter in the pore size distribution where <NUM>% of the pores have an equal or smaller diameter, and <NUM>% have a larger diameter. The median pore diameter (MPD) and breadth Db of the pore size distribution may be measured by mercury porosimetry, for example.

The cell density (CD) of the honeycomb body, <NUM>, <NUM>, <NUM>, <NUM> may be may be <NUM> cells/in<NUM> (<NUM> cells/cm<NUM>) ≤ CD ≤ <NUM> cells/in<NUM> (<NUM> cells/cm<NUM>), or even <NUM> cells/in<NUM> (<NUM> cells/cm<NUM>) ≤ CD ≤ <NUM> cells/in<NUM> (<NUM> cells/cm<NUM>), or even <NUM> cells/in<NUM> (<NUM> cells/cm<NUM>) ≤ CD ≤ <NUM> cells/in<NUM> (<NUM> cells/cm<NUM>), and may be CD ≥ <NUM> cells/in<NUM> (<NUM> cells/cm<NUM>), or even CD ≥ <NUM> cells/in<NUM> (<NUM> cells/cm<NUM>) in some embodiments. Other cell densities may be used. The above described %P, Tw, Db, MPD, and CD may be combined in any combination with each other and with the repeating structural units described herein.

For each of the embodiments of <FIG>, <FIG>, and <FIG>, the areas A<NUM> through A<NUM> may be sized in accordance with the relationships defined below, wherein in each embodiment, the channels <NUM>-<NUM> comprise quadrilateral shape in cross-section, and the fourth channel <NUM> is an outlet channel and has a quadrilateral and rectangular cross-sectional shape in transverse cross-section. In other embodiments, the quadrilateral cross-sectional shape in the repeating structural unit <NUM>, <NUM> may comprise some rectangular channels and some square channels. Furthermore, in each embodiment, the repeating structural unit <NUM>, <NUM>, <NUM>, <NUM> has a quadrilateral outer perimeter shape, such as a rectangular or even a square outer perimeter shape.

The structure of the repeating structural units <NUM>, <NUM>, <NUM>, <NUM> is selected to provide combinations of good soot carrying capacity, low clean pressure drop, as well as low pressure drop increase as a function of soot and/or ash loading. More particularly, in the inventive embodiments, the geometrical structure of the repeating structural unit <NUM>, <NUM>, <NUM>, <NUM> comprises A<NUM>≥A<NUM>>A<NUM>≥ A<NUM>. Furthermore, the first channel <NUM> and third channel <NUM> is be sized so that a ratio of A<NUM>/A<NUM> is A<NUM>/A<NUM>≥ <NUM>, or even may be A<NUM>/A<NUM> ≥ <NUM>, or even A<NUM>/A<NUM> ≥ <NUM>, or even A<NUM>/A<NUM> ≥ <NUM>, or even A<NUM>/A<NUM> ≥ <NUM> in some embodiments. The ratio of A<NUM>/A<NUM> is A<NUM>/A<NUM> ≤ <NUM>. In some embodiments, the ratio of A<NUM>/A<NUM> may comprise A<NUM>/A<NUM> ≤ <NUM>, or even A<NUM>/A<NUM> ≤ <NUM>. The ratio of A<NUM>/A<NUM> is <NUM> ≤ A<NUM>/A<NUM> ≤ <NUM>, or may be even <NUM> ≤ A<NUM>/A<NUM> ≤ <NUM>, or even <NUM> ≤ A<NUM>/A<NUM> ≤ <NUM>, for example. A<NUM> may be <NUM> in<NUM> (<NUM><NUM>) ≤ A<NUM> ≤ <NUM> in<NUM> (<NUM><NUM>), and A<NUM> may be <NUM> in<NUM> (<NUM><NUM>) ≤ A<NUM> ≤ <NUM> in<NUM> (<NUM><NUM>), for example. In some embodiments, the structure of the repeating structural units <NUM>, <NUM>, <NUM>, <NUM> comprises A<NUM>/A<NUM> ≤ <NUM> and OFA > <NUM>%, or even A<NUM>/A<NUM> ≤ <NUM> and OFA > <NUM>%.

Similarly, for the disclosed embodiments of <FIG>, <FIG>, and <FIG>, the geometrical structure of the repeating structural units <NUM>, <NUM>, <NUM>, <NUM> may comprise a ratio of A<NUM>/A<NUM> ≥ <NUM>, or even A<NUM>/A<NUM> ≥ <NUM>, or even A<NUM>/A<NUM> ≥ <NUM>, or even A<NUM>/A<NUM> ≥ <NUM>, or even A<NUM>/A<NUM> ≥ <NUM>. In some embodiments, the ratio of A<NUM>/A<NUM> may be A<NUM>/A<NUM> ≤ <NUM>. In some embodiments, the ratio of A<NUM>/A<NUM> may be A<NUM>/A<NUM> ≤ <NUM>, or even A<NUM>/A<NUM> ≤ <NUM>, for example. In some embodiments, the ratio of A<NUM>/A<NUM> may be <NUM> ≤ A<NUM>/A<NUM> ≤ <NUM>, or even <NUM> ≤ A<NUM>/A<NUM> ≤ <NUM>, or even <NUM> ≤ A<NUM>/A<NUM> ≤ <NUM>. A<NUM> may be <NUM> in<NUM> (<NUM><NUM>) ≤ A<NUM> ≤ <NUM> in<NUM> (<NUM><NUM>) and A<NUM> may be <NUM> in<NUM> (<NUM><NUM>) ≤ A<NUM> ≤ <NUM> in<NUM> (<NUM><NUM>). for example.

As is shown in the embodiments of <FIG>, <FIG>, and <FIG>, L<NUM>=L<NUM> and W<NUM>≠FW<NUM>. The presence of L<NUM>=L<NUM> in the configurations shown can have an advantage that such extrusion dies are easy to manufacture by virtue of equally-spaced due cuts in one direction that can be made such as by wire EDM or saw cutting entirely across one direction (e.g., along a height direction) of the extrusion die (vertically as shown). Moreover, in the honeycomb body <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, the porous walls <NUM> may extend from one portion of the skin <NUM> to another portion of the skin <NUM> such that all the intersecting porous walls <NUM> extend continuously in a straight line across the inlet face <NUM> and outlet face <NUM>. In the other orthogonal direction (e.g., horizontally as shown), non-equally-spaced due cuts can be made, but also such as by wire EDM or saw cutting entirely across a width of the extrusion die in a straight line resulting in horizontal walls of the intersecting porous walls <NUM> that extend continuously across a width of honeycomb body <NUM>, <NUM>, <NUM>, <NUM>, <NUM>.

As is shown in the embodiments of <FIG>, <FIG>, and <FIG>, the respective repeating structural units <NUM>-<NUM> may comprise geometrical structure wherein W<NUM>/W<NUM> ≥ <NUM>, or even W<NUM>/W<NUM> ≥ <NUM>, or even W<NUM>/W<NUM> ≥ <NUM>, or even W<NUM>/W<NUM> ≥ <NUM>, or even W<NUM>/W<NUM> ≥ <NUM>. In some embodiments, W<NUM>/W<NUM> ≤ <NUM>, or even W<NUM>/W<NUM> ≤ <NUM>, or even W<NUM>/W<NUM> ≤ <NUM>. In some embodiments, the ratio of W<NUM>/W<NUM> may be <NUM> ≤ W<NUM>/W<NUM> ≤ <NUM>, or even <NUM> ≤ W<NUM>/W<NUM> ≤ <NUM>, or even <NUM> ≤ W<NUM>/W<NUM> ≤ <NUM>, for example. W<NUM> may be <NUM> inch (<NUM>) ≤ W<NUM> ≤ <NUM> inch (<NUM>) and W<NUM> may be <NUM> inch (<NUM>) ≤ W<NUM> ≤ <NUM> inch (<NUM>), for example. In some embodiments, <NUM> ≤ W<NUM>/L<NUM> ≤ <NUM> and <NUM> ≤ W<NUM>/L<NUM> ≤ <NUM>, or even <NUM> ≤ W<NUM>/L<NUM> ≤ <NUM> and <NUM> ≤ W<NUM>/L<NUM> ≤ <NUM>, or even <NUM> ≤ W<NUM>/L<NUM> ≤ <NUM> and <NUM> ≤ W<NUM>/L<NUM> ≤ <NUM>.

In one particularly effective example comprising the configuration of any of the repeating structural units <NUM>, <NUM>, <NUM>, or <NUM>, the honeycomb structure comprises a wall thickness Tw of the intersecting porous walls <NUM> of <NUM> inch (<NUM>) ≤ Tw ≤ <NUM> inch (<NUM>), an open porosity (%P) of the intersecting porous walls <NUM> of <NUM>% ≤ P% ≤ <NUM>%, a median pore size (MPS) of the porous walls <NUM> of <NUM> microns ≤ MPS ≤ <NUM> microns, an inlet open frontal area (inlet OFA) of <NUM>% ≤ inlet OFA ≤ <NUM>%, and the ratio of W<NUM>/W<NUM> is <NUM> ≤ W<NUM>/W<NUM> ≤ <NUM>. Other geometrical features such as L<NUM>=L<NUM>, L<NUM>>L<NUM>, or even L<NUM><L<NUM> may be included.

As is shown in the embodiments of <FIG>, <FIG>, and <FIG>, the respective repeating structural units <NUM>-<NUM> may comprise geometrical structure wherein an area fraction of a cross-sectional area of the fourth channel <NUM> (comprising an outlet cell) divided by a cross-sectional area of all channels <NUM>-<NUM> of the repeating structural units <NUM>-<NUM> may be between <NUM> and <NUM>.

In certain embodiments of the repeating structural units <NUM>, <NUM>, such as those shown in <FIG>, <FIG>, and <FIG>, the first channel <NUM> and the second channel <NUM> comprise a same first rectangular shape in transverse cross-section, and the third channel <NUM> and the fourth channel <NUM> comprise a same second rectangular shape. Moreover, in these embodiments, the first channel <NUM>, the second channel <NUM>, and the third channel <NUM> are inlet channels, and the fourth channel <NUM> is an outlet channel. In particular, in these embodiments the respective areas of the channels may be sized in accordance with the relationship: A<NUM>=A<NUM>>A<NUM>=A<NUM>.

In other embodiments of the repeating structural unit <NUM>, such as is shown in <FIG>, the first channel <NUM> and the second channel <NUM> comprise different-sized quadrilateral shapes in transverse cross-section, and the third channel <NUM> and the fourth channel <NUM> also comprise different-sized quadrilateral shapes in transverse cross-section. In particular, in one embodiment, all four channels <NUM>-<NUM> may have a rectangular shape in transverse cross-section. Moreover, in these embodiments, the first channel <NUM>, the second channel <NUM>, and third channel <NUM> are inlet channels, and the fourth channel <NUM> is an outlet channel. In particular, in some embodiments, the respective areas of the channels may be sized in accordance with the relationship: A<NUM>≠A<NUM>>A<NUM>≠A<NUM>. In the <FIG> embodiment, L<NUM>/L<NUM> ≥ <NUM>, or even L<NUM>/L<NUM> ≥ <NUM>, or even L<NUM>/L<NUM> ≥ <NUM>, or even L<NUM>/L<NUM> ≥ <NUM> or even L<NUM>/L<NUM> ≥ <NUM>. In some embodiments, L<NUM>/L<NUM> ≤ <NUM>, L<NUM>/L<NUM> ≤ <NUM>, or even L<NUM>/L<NUM> ≤ <NUM>. In some of the <FIG> embodiments, L<NUM>/L<NUM> may be <NUM> ≤ L<NUM>/L<NUM> ≤ <NUM>, or even <NUM> ≤ L<NUM>/L<NUM> ≤ <NUM>, or even <NUM> ≤ L<NUM>/L<NUM> ≤ <NUM>.

Referring now to <FIG>, a particularly effective embodiment of the repeating structural unit <NUM> of a honeycomb body <NUM> is shown. In the depicted embodiment, the repeating structural unit <NUM> of the honeycomb body <NUM> comprises a first channel <NUM>, a second channel <NUM>, a third channel <NUM>, and a fourth channel <NUM> as previously described, but wherein the respective areas of the channels may be sized in accordance with the relationship: A<NUM>=A<NUM>>A<NUM>=A<NUM>. Furthermore, the first channel <NUM> and the second channel <NUM> comprise a same first square shape in transverse cross-section and are inlet channels, the third channel <NUM> is an inlet channel, and the fourth channel <NUM> is an outlet channel, and the third channel <NUM> and the fourth channel <NUM> comprise a same second rectangular shape in transverse cross-section.

In particular, for the embodiment of <FIG>, the repeating structural unit <NUM> may comprise a geometrical structure wherein L<NUM>=L<NUM> and W<NUM>≠FW<NUM>. The third channel <NUM> and the fourth channel <NUM> each comprises a rectangular shape wherein W<NUM>>L<NUM> and W<NUM>>L<NUM>. In particular, for this embodiment, W<NUM>>W<NUM>. For this embodiment, a ratio of A<NUM>/A<NUM> may be A<NUM>/A<NUM> ≥ <NUM>, or even A<NUM>/A<NUM> ≥ <NUM>, or even A<NUM>/A<NUM> ≥ <NUM>, or even A<NUM>/A<NUM> ≥ <NUM>, or even A<NUM>/A<NUM> ≥ <NUM>. For this embodiment, a ratio of A<NUM>/A<NUM> may be A<NUM>/A<NUM> ≤ <NUM>, or even A<NUM>/A<NUM> ≤ <NUM>, and in some embodiments may be A<NUM>/A<NUM> ≤ <NUM>. For this embodiment, A<NUM>/A<NUM> may be <NUM> ≤ A<NUM>/A<NUM> ≤ <NUM>, or even <NUM> ≤ A<NUM>/A<NUM> ≤ <NUM>, or even between <NUM> ≤ A<NUM>/A<NUM> ≤ <NUM> in some embodiments.

Examples of honeycomb bodies <NUM>, <NUM>, <NUM>, and <NUM> comprising the honeycomb structure shown in the <FIG> embodiments are provided in Table <NUM> below. A<NUM> through A<NUM> are the transverse cross-sectional areas of the respective inlet channels, whereas A<NUM> is the transverse cross-sectional area of the rectangular outlet channel. Additionally, estimated performance based upon modeling for the various embodiments, including comparisons to comparative examples <NUM>-<NUM> (Comp. <NUM>-<NUM>) are shown below in Table <NUM>. In particular, percentage improvements (% IMP) in pressure drop (ΔP) performance under various conditions in comparison to various comparative examples (Comp. <NUM>-<NUM>) are provided. In the table <NUM> inch corresponds with <NUM>.

Embodiments wherein L<NUM>=L<NUM> and W<NUM> >W<NUM> are shown in Ex. <NUM>-<NUM>, and Ex. <NUM>-<NUM>, and <NUM> wherein Ex. <NUM> has all rectangles. Embodiments where L<NUM>≠L<NUM> are shown in Ex. <NUM>-<NUM> and comp. Combination embodiments wherein both L<NUM>≠L<NUM> and W<NUM> >W<NUM> are shown in Ex. <NUM>-<NUM>. An example wherein L<NUM>≠FL<NUM> and W<NUM>=W<NUM> is shown in comp. In particular, in Ex. <NUM>, the configuration comprises L<NUM><L<NUM>. An example wherein L<NUM>=L<NUM> and W<NUM>=W<NUM>, but wherein W<NUM>≠L<NUM> is shown in comp. In particular, in comp. <NUM>, W<NUM>>L<NUM>. However, optionally, the repeating structural unit may comprise L<NUM>=L<NUM> and W<NUM>=W<NUM>, but W<NUM><L<NUM>.

Referring now to <FIG>, a particulate filter <NUM> comprising the honeycomb body <NUM> (or optionally, honeycomb bodies <NUM>-<NUM>) is shown. In the depicted embodiment, the honeycomb body <NUM> is received inside of a can <NUM>, such as a metal housing or other confining structure. Can <NUM> may comprise a first end cap comprising an inlet <NUM> configured to receive engine exhaust <NUM> containing soot and/or inorganic particulates, and a second end cap comprising an outlet <NUM> configured to exhaust a filtered gas flow, wherein a large percentage (e.g., approximately <NUM>% or greater) of the particulates <NUM> (e.g., soot and/or inorganic matter) in the engine exhaust have been removed/filtered and are carried in the inlet channels <NUM> and open interconnected porosity of the honeycomb body <NUM>. The skin <NUM> of the honeycomb body <NUM> may have a member <NUM> in contact therewith, such as a high-temperature insulation material, to cushion the honeycomb body <NUM> from shock and stress. Any suitable construction of the member <NUM> may be used, such as one-piece construction, or two or more layer construction. The honeycomb body <NUM> and member <NUM> may be received in the can <NUM> by any suitable means, such as by funneling into the central body and then one or more of the first and second end caps may be secured (e.g., welded) onto the central body for form the inlet <NUM> and the outlet <NUM>. Other, two-piece construction or clam-shell construction of the can <NUM> may optionally be used.

<FIG> illustrates an exhaust system <NUM> coupled to an engine <NUM> (e.g., a gasoline engine or diesel engine). The exhaust system <NUM> may comprise a manifold <NUM> for coupling to the exhaust ports of the engine <NUM>, a first collection tube <NUM> configured to couple between the manifold <NUM> and the particulate filter <NUM> containing the honeycomb body <NUM> therein. Coupling may be by any suitable clamping bracket or other attachment mechanism. The first collection tube <NUM> may be integral with the manifold <NUM> in some embodiments. In some embodiments, the particulate filter <NUM> may couple directly to the manifold without an intervening member. The exhaust system <NUM> may further comprise a second collection tube <NUM> coupled to the particulate filter <NUM> and to a second exhaust component <NUM>. The second exhaust component <NUM> may be a muffler, a catalytic converter, or even a second particulate filter, for example. A tailpipe <NUM> (shown truncated) or other conduit or component may be coupled to the second exhaust component <NUM>. Other exhaust system components may be included, such as oxygen sensors, ports for urea injection, and the like (not shown). The engine <NUM> may comprise one particulate filter <NUM> for each bank (side set of cylinders) of the engine <NUM>, or optionally, the first collection tube <NUM> may be a Y-tube collecting soot from each bank and directing the soot to the particulate filter <NUM>. Utilizing the particulate filter <NUM> comprising the honeycomb body <NUM> according to embodiments described herein may result in long intervals between regeneration events due to the relatively large ash and soot loading capability of the particulate filter <NUM>. Moreover, the relatively low back pressure exerted by the honeycomb body <NUM> in the exhaust system <NUM> may allow for free exhaust flow and thus substantially minimal power reduction of the engine <NUM>. The exhaust system <NUM> comprising the honeycomb body <NUM> preferably provides, in some embodiments, very low clean pressure drop, low soot-loaded and ash-loaded pressure drop, as well as low rate of increase in pressure drop as a function of soot and/or ash loading. The exhaust system <NUM> is described as comprising honeycomb body <NUM> shown and described with reference to <FIG>. However, other honeycomb bodies <NUM>, <NUM>, <NUM>, and <NUM> may be substituted therein.

Referring now to <FIG>, a honeycomb extrusion die <NUM> configured to manufacture the honeycomb bodies <NUM>-<NUM> according to embodiments of the disclosure is provided. The honeycomb bodies <NUM>-<NUM> may be formed by extrusion of a batch mixture, such as is described, for example, in <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, and <CIT>, through the honeycomb extrusion die <NUM> to produce a green honeycomb body. The green honeycomb body may then be dried, such as described in <CIT>, <CIT>, <CIT>, and <CIT>, for example. The green honeycomb body may then be fired, such as described in <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, and <CIT> to form the honeycomb body <NUM>-<NUM> with a porous ceramic wall honeycomb structure comprising the geometry (or structure) and microstructure described herein.

The honeycomb extrusion die <NUM> comprises a die body <NUM>, a die inlet face <NUM> configured to receive extrudable batch mixture, and a die outlet face <NUM> opposite from the die inlet face <NUM> configured to expel batch material in the form of a green honeycomb body having a honeycomb structure. The extrusion die <NUM> may be coupled to an extruder (not shown) that receives the batch, such as a ram extruder or screw extruder such as a twinscrew extruder, wherein the extruder forces the batch material under pressure through the extrusion die <NUM>.

The honeycomb extrusion die <NUM> comprises a plurality of feedholes <NUM> (a few labeled) extending from the die inlet face <NUM> into the die body <NUM>, and an intersecting with an array of slots <NUM> (a few labeled) extending into the die body <NUM> from the die outlet face <NUM> and connecting with the plurality of feedholes <NUM>. The feedholes <NUM> supply batch to the array of slots <NUM>. The intersecting array of slots <NUM> comprises first slots <NUM> (a few labeled) extending in a straight line entirely across the die outlet face <NUM> (e.g., vertically as shown), and a second slots <NUM> which may be orthogonal to the first slots <NUM> and may also extend in a straight line fully across the die outlet face <NUM> (e.g., horizontally as shown). The intersecting array of slots <NUM> form an array of unit die cells <NUM> that are repeated across at least some of the die outlet face <NUM>, and may encompass the substantial entirely the die outlet face <NUM>. The unit die cells <NUM> may be arranged, as shown, in a side-by-side abutting relationship in the horizontal direction, and stacked one atop another in the vertical direction, for example. The honeycomb extrusion die <NUM> may comprise a skin-forming portion <NUM> comprising a skin-forming mask <NUM> (e.g., a ring-shaped article) that interfaces with skin forming feedholes <NUM> to form an extruded skin on the extruded green honeycomb body formed during the extrusion method.

Each of the unit die cells <NUM> comprises a first die component <NUM>, a second die component <NUM>, a third die component <NUM>, and a fourth die component <NUM>, which may be arranged as shown in <FIG>. Each die component <NUM>-<NUM> comprises a die pin (P1-P4, respectively) and a width Ws of a slot of the intersecting array of slots <NUM> around the perimeter (half the width Ws on each side). First die component <NUM> comprises, in cross-section, a length L<NUM>', a width W<NUM>', and a cross-sectional area A<NUM>'. The second die component <NUM> comprises, in cross-section, a length L<NUM>', the width W<NUM>', and a cross-sectional area A<NUM>'. The third die component <NUM> comprises, in cross-section, the length L<NUM>', a width W<NUM>', and a cross-sectional area A<NUM>', and the fourth die component <NUM> comprises, in cross-section, the length L<NUM>', the width W<NUM>', and a cross-sectional area A<NUM>', wherein fourth die component <NUM> comprises a rectangular shape in cross-section. The cross-section is through the pins (P1-P4) in a plane parallel to the die outlet face <NUM>.

The die components <NUM>-<NUM> may be configured in a first configuration, that is, the configuration of the die components <NUM>-<NUM> can be selected to provide at least one of a first configuration, wherein the first configuration is:
W<NUM>'>W<NUM>' and L<NUM>'=L<NUM>' and A<NUM>'=A<NUM>'>A<NUM>'=A<NUM>'.

The unit die cell <NUM> comprises a first configuration and structure wherein W<NUM>' > W<NUM>' and L<NUM>' = L<NUM>' and the third die component <NUM> and the fourth die component <NUM> comprise the same quadrilateral (e.g., rectangular) shape, and the first die component <NUM> and the second die component <NUM> comprise the same quadrilateral shape, and the unit die cell <NUM> has an outer peripheral shape that is also quadrilateral (e.g., rectangular or square).

The first combination can comprise a unit die cell <NUM> that comprises structure wherein the area of the die components <NUM>-<NUM> are related by the relationship: A<NUM>' = A<NUM>' > A<NUM>' = A<NUM>'. In particular, a ratio of A<NUM>'/A<NUM>' may be A<NUM>'/A<NUM>' ≥ <NUM>, or even A<NUM>'/A<NUM>' ≥ <NUM>, or even A<NUM>'/A<NUM>' ≥ <NUM>, or even A<NUM>'/A<NUM>' ≥ <NUM>, or even A<NUM>'/A<NUM>' ≥ <NUM>. A<NUM>'/A<NUM>' may be <NUM> ≤ A<NUM>'/A<NUM>' ≤ <NUM>, or even <NUM> ≤ A<NUM>'/A<NUM>' ≤ <NUM>, or even <NUM> ≤ A<NUM>'/A<NUM>' ≤ <NUM>. Similarly, the ratio of A<NUM>'/A<NUM>' may be A<NUM>'/A<NUM>' ≥ <NUM>, or even A<NUM>'/A<NUM>' ≥ <NUM>, or even A<NUM>'/A<NUM>' ≥ <NUM>, or even A<NUM>'/A<NUM>' ≥ <NUM>, or even A<NUM>'/A<NUM>' ≥ <NUM>. A<NUM>'/A<NUM>' may be <NUM> ≤ A<NUM>'/A<NUM>' ≤ <NUM>, or even <NUM> ≤ A<NUM>'/A<NUM>' ≤<NUM>, or even <NUM> ≤ A<NUM>'/A<NUM>' ≤ <NUM>.

Where W<NUM>'>W<NUM>', a ratio of W<NUM>'/W<NUM>' may be <NUM> ≤ W<NUM>'/W<NUM>' ≤ <NUM>, or even between <NUM> ≤ W<NUM>'/W<NUM>' ≤ <NUM>. Where L<NUM>'>L<NUM>', a ratio of ratio of L<NUM>'/L<NUM>' may be L<NUM>'/L<NUM>' ≥ <NUM>, or even L<NUM>'/L<NUM>' ≥ <NUM>, or even L<NUM>'/L<NUM>' ≥ <NUM>, or even L<NUM>'/L<NUM>' ≥ <NUM>, or even L<NUM>'/L<NUM>' ≥ <NUM>, or even L<NUM>'/L<NUM>' ≥ <NUM>. L<NUM>'/L<NUM>' may be <NUM> ≤ L<NUM>'/L<NUM>' ≤ <NUM>, or even <NUM> ≤ L<NUM>'/L<NUM>' ≤ <NUM>, or even <NUM> ≤ L<NUM>'/L<NUM>' ≤ <NUM>.

Where L<NUM>'<L<NUM>', a ratio of ratio of L<NUM>'/L<NUM>', may be <NUM> ≥ L<NUM>'/L<NUM>' ≥ <NUM>, or even L<NUM>'/L<NUM>' may be <NUM> ≥ L<NUM>'/L<NUM>' ≥ <NUM>, or even L<NUM>'/L<NUM>' may be <NUM> ≥ L<NUM>'/L<NUM>' ≥ <NUM>. However, the fourth die component <NUM> is always rectangular in cross-section. L<NUM>'/L<NUM>' may be L<NUM>'/L<NUM>' ≥ <NUM> or0. <NUM> ≤ L<NUM>'/L<NUM>' ≤ <NUM>.

<FIG> illustrate several honeycomb extrusion dies <NUM>, 800A, 800B, which comprise different feedhole patterns (feedholes <NUM> shown as dotted circles and slots shown as solid lines). <FIG> illustrates a first die wherein feedholes <NUM> are included at every intersection of the slots and also midway between intersections of the larger die pins P3, P4 of the unit die cell <NUM>. This feedhole configuration may be used in the honeycomb extrusion die <NUM> where the ratio of W<NUM>'/W<NUM>' is relatively larger, such as greater than <NUM>, for example.

<FIG> illustrates a honeycomb extrusion die 800A wherein feedholes <NUM> are included at every other intersection of the slots in both directions so that feedholes <NUM> are included on the sides, but not the corners, of the die unit cell 824A. The <FIG> die of honeycomb extrusion die 800A may be used where the ratio of W<NUM>'/W<NUM>' is relatively smaller, such as less than or equal to about <NUM>, for example.

<FIG> illustrates a honeycomb extrusion die 800B wherein feedholes <NUM> are included at every other horizontal intersection of the horizontal slots, and at vertical locations so that the intersection at the center C of every die unit cell 824B is fed batch from four directions. The <FIG> die, may be used in where the ratio of W<NUM>'/W<NUM>' is relatively smaller, such as less than or equal to <NUM>, for example.

<FIG> describes a method <NUM> of filtering particulates according to one or more embodiments. The method <NUM> comprises, in <NUM>, providing a honeycomb body (e.g., honeycomb body <NUM>, <NUM>, <NUM>, <NUM>, or <NUM>) as described herein and embodied in a particulate filter (e.g., particulate filter <NUM>), and, in <NUM>, capturing soot in the honeycomb body.

Claim 1:
A honeycomb body, comprising:
intersecting porous walls in a matrix comprising a pattern of repeating structural units, wherein each of the repeating structural units comprises a first cell, a second cell, a third cell, and a fourth cell, wherein the first cell, second cell, third cell, and fourth cell all extend parallel to each other in an axial direction from an inlet face to an outlet face and have a quadrilateral cross-section in a transverse plane orthogonal to the axial direction and are plugged to define inlet channels and outlet channels within the repeating structural unit, wherein each of the repeating structural units comprises:
a first channel defined by the first cell comprising, in transverse cross-section, a length L<NUM>, a width W<NUM>, and a cross-sectional area A<NUM>, the first channel having a first sidewall and a second sidewall orthogonal to the first sidewall;
a second channel defined by the second cell and comprising, in transverse cross-section, a length L<NUM>, the width W<NUM>, and a cross-sectional area A<NUM>, and sharing the second sidewall with the first channel;
a third channel defined by the third cell comprising, in transverse cross-section, the length L<NUM>, a width W<NUM>, and a cross-sectional area A<NUM>, comprising a third sidewall and sharing the first sidewall with the first channel; and
a fourth channel defined by the fourth cell and comprising, in transverse cross-section, the length L<NUM>, the width W<NUM>, and a cross-sectional area A<NUM>, and sharing a fourth sidewall with the second channel and the third sidewall with the third channel, and
wherein the first channel, the second channel, and the third channel are inlet channels and the fourth channel is an outlet channel having a rectangular shape, wherein a first two sides are of equal length and second two sides are of equal length and which have a length different than the length of the first two sides, in transverse cross-section,
at least one of W<NUM>≥W<NUM> and L<NUM>≠L<NUM>, and the repeating structural unit comprises a quadrilateral outer perimeter,
wherein A<NUM>≥ A<NUM> > A<NUM>≥ A<NUM>, and
wherein <NUM> ≤ A<NUM>/A<NUM> ≤ <NUM>.