Patent Publication Number: US-2021180489-A1

Title: Roller drum plugging of honeycomb bodies

Description:
This application claims the benefit of priority under 35 U.S.C. § 119 of U.S. Provisional Application Ser. No. 62/693,670 filed on Jul. 3, 2018, which is incorporated herein by reference in its entirety. 
    
    
     FIELD OF THE DISCLOSURE 
     The present disclosure generally relates to ceramic honeycomb bodies used as filters, and more specifically, to methods of plugging honeycomb bodies. 
     BACKGROUND 
     Ceramic wall flow filters typically have porous honeycomb structures with the plugs sealing alternate channels, which force exhaust gas flow through porous channel walls to exit from adjoining channels. 
     SUMMARY OF THE DISCLOSURE 
     A method of plugging a honeycomb body is disclosed herein, the method comprising: applying a mask layer to the honeycomb body defining a plurality of channels, wherein the mask layer defines a plurality of holes aligned with the plurality of channels; rotating a roller drum; moving the honeycomb body over the roller drum to define a nip between the roller drum and the honeycomb body; and inserting a plugging cement in the nip between the roller drum and the mask layer such that the roller drum forces the plugging cement through the plurality of holes of the mask layer into the plurality of channels of the honeycomb body. 
     Also disclosed herein is a method of plugging a honeycomb body, the method comprising: applying a mask layer to the honeycomb body defining a plurality of channels, wherein the mask layer defines a plurality of holes aligned with the plurality of channels; rotating a roller drum defining one or more embossed features; moving the honeycomb body over the embossed features of the roller drum to define a nip between the one or more embossed features and the mask layer; and inserting a plugging cement in the nip such that the one or more embossed features forces the plugging cement through the plurality of holes of the mask layer into the plurality of channels of the honeycomb body. 
     Also disclosed herein is a method of plugging a honeycomb body, the method comprising: applying a mask layer to the honeycomb body defining a plurality of channels, wherein the mask layer defines a plurality of holes aligned with the plurality of channels; rotating a roller drum defining a plurality of embossed features; moving the honeycomb body over the plurality of embossed features of the roller drum to define a nip between plurality of embossed features and the mask layer; and conveying a plugging cement along a carrier web through the nip between the embossed features of the roller drum and the mask layer such that the embossed features forces the plugging cement through the plurality of holes of the mask layer into the plurality of channels of the honeycomb body. 
     These and other features, advantages, and objects of the present disclosure will be further understood and appreciated by those skilled in the art by reference to the following specification, claims, and appended drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The following is a description of the figures in the accompanying drawings. The figures are not necessarily to scale, and certain features and certain views of the figures may be shown exaggerated in scale or in schematic in the interest of clarity and conciseness. 
       In the drawings: 
         FIG. 1  is a perspective view of a filter, according to at least one example; 
         FIG. 2  is a perspective view of the filter depicted in  FIG. 1  as including a plurality of plugs, according to at least one example; 
         FIG. 3  is a cross-sectional view taken at line of  FIG. 2 , according to at least one example; and 
         FIG. 4  is a schematic illustration of a method of forming the filter, according to at least one example. 
     
    
    
     DETAILED DESCRIPTION 
     Additional features and advantages of the invention will be set forth in the detailed description which follows and will be apparent to those skilled in the art from the description, or recognized by practicing the invention as described in the following description, together with the claims and appended drawings. 
     As used herein, the term “and/or,” when used in a list of two or more items, means that any one of the listed items can be employed by itself, or any combination of two or more of the listed items can be employed. For example, if a composition is described as containing components A, B, and/or C, the composition can contain A alone; B alone; C alone; A and B in combination; A and C in combination; B and C in combination; or A, B, and C in combination. 
     In this document, relational terms, such as first and second, top and bottom, and the like, are used solely to distinguish one entity or action from another entity or action, without necessarily requiring or implying any actual such relationship or order between such entities or actions. 
     Modifications of the disclosure will occur to those skilled in the art and to those who make or use the disclosure. Therefore, it is understood that the embodiments shown in the drawings and described above are merely for illustrative purposes and not intended to limit the scope of the disclosure, which is defined by the following claims, as interpreted according to the principles of patent law, including the doctrine of equivalents. 
     It will be understood by one having ordinary skill in the art that construction of the described disclosure, and other components, is not limited to any specific material. Other exemplary embodiments of the disclosure disclosed herein may be formed from a wide variety of materials, unless described otherwise herein. 
     For purposes of this disclosure, the term “coupled” (in all of its forms: couple, coupling, coupled, etc.) generally means the joining of two components (electrical or mechanical) directly or indirectly to one another. Such joining may be stationary in nature or movable in nature. Such joining may be achieved with the two components (electrical or mechanical) and any additional intermediate members being integrally formed as a single unitary body with one another or with the two components. Such joining may be permanent in nature, or may be removable or releasable in nature, unless otherwise stated. 
     As used herein, the term “about” means that amounts, sizes, formulations, parameters, and other quantities and characteristics are not and need not be exact, but may be approximate and/or larger or smaller, as desired, reflecting tolerances, conversion factors, rounding off, measurement error and the like, and other factors known to those of skill in the art. When the term “about” is used in describing a value or an end-point of a range, the disclosure should be understood to include the specific value or end-point referred to. Whether or not a numerical value or end-point of a range in the specification recites “about,” the numerical value or end-point of a range is intended to include two embodiments: one modified by “about,” and one not modified by “about.” It will be further understood that the end-points of each of the ranges are significant both in relation to the other end-point, and independently of the other end-point. 
     The construction and arrangement of the elements of the present disclosure, as shown in the exemplary embodiments, is illustrative only. Although only a few embodiments of the present innovations have been described in detail in this disclosure, those skilled in the art who review this disclosure will readily appreciate that many modifications are possible (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters, mounting arrangements, use of materials, colors, orientations, etc.) without materially departing from the novel teachings and advantages of the subject matter recited. For example, elements shown as integrally formed may be constructed of multiple parts, or elements shown as multiple parts may be integrally formed, the operation of the interfaces may be reversed or otherwise varied, the length or width of the structures, and/or members, or connectors, or other elements of the system, may be varied, and the nature or number of adjustment positions provided between the elements may be varied. It should be noted that the elements and/or assemblies of the system may be constructed from any of a wide variety of materials that provide sufficient strength or durability, in any of a wide variety of colors, textures, and combinations. Accordingly, all such modifications are intended to be included within the scope of the present innovations. Other substitutions, modifications, changes, and omissions may be made in the design, operating conditions, and arrangement of the desired and other exemplary embodiments without departing from the spirit of the present innovations. 
       FIGS. 1 and 2  show a filter  10  comprising a honeycomb body  14  comprising a first end  18  and a second end  22 . The honeycomb body  14  comprises intersecting cell walls that form a plurality of channels  26  extending from the first end  18  to the second end  22 . According to various examples, a filter  10  comprises a plurality of plugs  30  positioned within at least some of the channels  26 , in some embodiments at first and second ends  18 ,  22 , of the honeycomb body  14 . 
     Referring now to  FIG. 1 , the honeycomb body  14  comprises a matrix of intersecting cell walls comprise thin, porous walls  38  which extend across and between the first and second ends  18 ,  22  to form a large number of adjoining channels  26 . The channels  26  extend between and are open at the first and second ends  18 ,  22  of the honeycomb body  14 . According to various examples, the channels  26  are mutually parallel with one another. The honeycomb body  14  may comprise a transverse cross-sectional channel density of from about 10 channels/in 2  to about 900 channels/in 2 , or from about 20 channels/in 2  to about 800 channels/in 2 , or from about 30 channels/in 2  to about 700 channels/in 2 , or from about 40 channels/in 2  to about 600 channels/in 2 , 50 channels/in 2  to about 500 channels/in 2 , or from about 60 channels/in 2  to about 400 channels/in 2 , or from about 70 channels/in 2  to about 300 channels/in 2 , or from about 80 channels/in 2  to about 200 channels/in 2 , or from about 90 channels/in 2  to about 100 channels/in 2 , or form about or from about 100 channels/in 2  to about 200 channels/in 2  or any and all values and ranges therebetween. The walls  38  may have a thickness in mils (i.e., thousands of an inch) of from about 1 mil to about 15 mils, or from about 1 mil to about 14 mils, or from about 1 mil to about 13 mils, or from about 1 mil to about 12 mils, or from about 1 mil to about 11 mils, or from about 1 mil to about 10 mils, or from about 1 mil to about 9 mils, or from about 1 mil to about 8 mils, or from about 1 mil to about 7 mils, or from about 1 mil to about 14 mils, or from about 1 mil to about 6 mils, or from about 1 mil to about 5 mils, or from about 1 mil to about 4 mils, or from about 1 mil to about 3 mils, or from about 1 mil to about 2 mils or any and all values and ranges therebetween. It will be understood that although the channels  26  are depicted with a generally square cross-sectional shape, the channels  26  may have a circular, triangular, rectangular, pentagonal or higher order polygon cross-sectional shape without departing from the teachings provided herein. 
     The honeycomb body  14  may be formed of a variety of materials including ceramics, glass-ceramics, glasses, metals, and by a variety of methods depending upon the material selected. According to various examples, a green body which is transformed into honeycomb body  14  may be initially fabricated from plastically formable and sinterable finely divided particles of substances that yield a porous material after being fired. Suitable materials for a green body which is formed into the honeycomb body  14  comprise metallics, ceramics, glass-ceramics, and other ceramic based mixtures. In some embodiments, the honeycomb body  14  is comprised of a cordierite (e.g., 2MgO.2Al 2 O 3 .5SiO 2 ) material. 
     Referring to  FIG. 2 , the filter  10  can be formed from the honeycomb body  14  by closing or sealing a first subset of channels  26 , such as at the first end  18  with plugs  30 , and the remaining channels  26  (for example alternating channels  26 ) being closed at the second end  22  of the honeycomb body  14 , using other plugs  30 . In operation of the filter  10 , fluids such as gases carrying solid particulates are brought under pressure to the inlet face (e.g., the first end  18 ). The gases then enter the honeycomb body  14  via the channels  26  which have an open end at the first end  18 , pass through the walls  38  of the porous cell walls, and out the channels  26  which have an open and at the second end  22 . Passing of the gasses through the walls  38  may allow the particulate matter in the gases to remain trapped by the walls  38 . 
     As schematically illustrated in  FIGS. 2 and 3 , plugs  30  may be positioned in the channels  26  in an alternating manner. In the depicted example, the plugs  30  are positioned across the first and second ends  18 ,  22  of the honeycomb body  14  in a “checkerboard” pattern, but it will be understood that other patterns may also be applied. In the checkerboard pattern, each of an open channel&#39;s  26  nearest neighbor channels  26  on an end (e.g., either the first or second end  18 ,  22 ) includes a plug  30 . 
     The plugs  30  may have an axial length, or longest dimension extending substantially parallel with the channels  26 , of about 0.5 mm or greater, of about 1 mm or greater, of about 1.5 mm or greater, of about 2 mm or greater, of about 2.5 mm or greater, of about 3 mm or greater, of about 3.5 mm or greater, of about 4 mm or greater, of about 4.5 mm or greater, of about 5 mm or greater, of about 5.5 mm or greater, of about 6.0 mm or greater, of about 6.5 mm or greater. For example, the plugs  30  may have an axial length of from about 0.5 mm to about 10 mm, or from about 1 mm to about 9 mm, or from about 1 mm to about 8 mm, or from about 1 mm to about 7 mm, or from about 1 mm to about 6 mm, or from about 1 mm to about 5 mm, or from about 1 mm to about 4 mm, or from about 1 mm to about 3 mm, or from about 1 mm to about 2 mm or any and all value and ranges therebetween. According to various examples, the plurality of plugs  30  located on the first end  18  of the body  14  may have a different length than the plugs  30  positioned on the second end  22  of the body  14 . 
     The variation in length for a plurality of plugs  30  may be expressed as a standard deviation and is calculated as the square root of variance by determining the variation between each length relative to the average length of the plugs  30 . The standard deviation of the plurality of plugs  30  is a measure of the variance in the length of plugs  30  positioned, for example, on either the first or second ends  18 ,  22  of the honeycomb body  14 . All of the plurality of plugs  30  on one end (e.g., the first or second end  18 ,  22 ) may have a standard deviation in length of from about 0.1 mm to about 3.0 mm. For example, a standard deviation in length of the plugs  30  may be about 3.0 mm or less, about 2.9 mm or less, about 2.8 mm or less, about 2.7 mm or less, about 2.6 mm or less, about 2.5 mm or less, about 2.4 mm or less, about 2.3 mm or less, about 2.2 mm or less, about 2.1 mm or less, about 2.0 mm or less, about 1.9 mm or less, about 1.8 mm or less, about 1.7 mm or less, about 1.6 mm or less, about 1.5 mm or less, about 1.4 mm or less, about 1.3 mm or less, about 1.2 mm or less, about 1.1 mm or less, about 1.0 mm or less, about 0.9 mm or less, about 0.8 mm or less, about 0.7 mm or less, about 0.6 mm or less, about 0.5 mm or less, about 0.4 mm or less, about 0.3 mm or less, about 0.2 mm or less, about 0.1 mm or less or any and all values and ranges therebetween. According to various examples, the plurality of plugs  30  located on the first end  18  of the body  14  may have a different standard deviation than the plugs  30  positioned on the second end  22  of the body  14 . 
     Referring now to  FIG. 4 , depicted is a method  50  of forming the filter  10 . The method  50  may begin with a step  54  of applying a mask layer  58  to the filter  10  defining the plurality of channels  26 . According to various examples, the mask layer  58  defines a plurality of holes  66  aligned with the plurality of channels  26 . The mask layer  58  may be applied to the first end  18  of the honeycomb body  14  and/or the second end  22  to cover the plurality of filter channels  26 . The mask layer  58  may be comprised of a metal, polymer, a composite material and/or combinations thereof. For example, the mask layer  58  may be comprised of a rice paper, cellophane, plexiglass, biaxially-oriented polyethylene terephthalate, other materials and/or combinations thereof. A mask layer  58  can be positioned on the first and/or second ends  18 ,  22  of the honeycomb body  14 . The mask layer  58  may cover a portion, a majority, substantially all or all of the first and/or second ends  18 ,  22 . The mask layer  58  may have the same size and shape as the first and/or second ends  18 ,  22 , or the size and/or shape of the mask layer  58  may be different. For example, the mask layer  58  may have the same general shape as a cross-section of the honeycomb body  14  (e.g., generally circular) and may have a greater diameter than the honeycomb body  14  such that the mask layer  58  extends radially outwardly from the honeycomb body  14 . The mask layer  58  may extend outwardly from the honeycomb body  14  about 0.5 cm or greater, about 1.0 cm or greater, about 1.5 cm or greater, about 2.0 cm or greater, about 2.5 cm or greater, about 3.0 cm or greater, about 3.5 cm or greater, about 4.0 cm or greater, about 4.5 cm or greater, about 5.0 cm or greater, about 5.5 cm or greater, about 6.0 cm or greater or any and all values and ranges therebetween. The mask layer  58  may be coupled to the honeycomb body  14 . For example, the honeycomb body  14  and/or mask layer  58  may have an adhesive adhered thereto, or disposed between, to allow sticking of the mask layer  58  to the honeycomb body  14 . In another example, a band may be positioned around an exterior surface of the honeycomb body  14  to retain the mask layer  58  to the honeycomb body  14 . 
     According to various examples, the mask layer  58  includes the plurality of holes  66  positioned across the mask layer  58 . The holes  66  of the mask layer  58  may be formed prior to coupling of the mask layer  58  to the honeycomb body  14  or after. The holes  66  may be positioned in a pattern (e.g., a checkerboard-like pattern) across the mask layer  58 . In checkerboard-like patterns, the holes  66  are positioned proximate every other channel  26  at a face (e.g., the first and/or second ends  18 ,  22 ). According to various examples, a plurality of holes  66  may be positioned over one or more of the channels  26 . The holes  66  facilitate fluid communication between the channel  26  and an environment around the mask layer  58 . The holes  66  may be formed through mechanical force (e.g., with a punch) or through a laser. 
     The holes  66  may take a variety of shapes. For example, the holes  66  may have a circular, oval, oblong, triangular, square, rectangular or higher order polygon shape. The holes  66  may have an area of from about 1% to about 80% of a cross-sectional area of the corresponding respective channel  26  aligned with the hole  66 . For example, the holes  66  may have an area of about 80% or less, about 75% or less, about 70% or less, about 65% or less, about 55% or less, about 50% or less, about 45% or less, about 40% or less, about 35% or less, about 30% or less, about 25% or less, about 20% or less, about 15% or less, about 10% or less, about 5% or less of a cross-sectional area of the channel  26  proximate the holes  66 . It will be understood that any and all values and ranges therebetween are contemplated. Use of the term aligned is meant to mean that the holes  66  may be positioned in a variety of locations over the channels  26  to allow fluid communication through the hole  66  and into the channel  26 . For example, the holes  66  may be positioned in a middle, a side, or around edges of the channels  26 . Further, it will be understood that two or more holes  66  may be positioned proximate each channel  26 . 
     Next, a step  74  of rotating a roller drum  78  is performed. The roller drum  78  may be fabricated from a tubular structure for a central portion of the roller drum  78  into which gudgeons are attached at each end to provide a mounting feature for bearing supports and attachment points for drive components. According to various examples, the roller drum  78  includes or defines one or more embossed features  82  on a surface  86  of the roller drum  78 . For example, the roller drum  78  may define a plurality of embossed features  82 . The embossed features  82  include a lip  90  which defines a well  94  between the lip  90  and the surface  86  of the roller drum  78 . For purposes of clarity, the roller drum  78  is depicted as including a single line, or circumferential location, at which the plurality of embossed features  82  are positioned, but it will be understood that the roller drum  78  may include multiple pluralities of embossed features  82 . For example, the roller drum  78  may include embossed features  82  extending across the length of the roller drum  78  in substantially the same manner or the embossed features  82  may be staggered relative to one another. 
     The lip  90  may be composed of a plastic, metal, composite material and/or combinations thereof. In polymeric examples, the lip  90  may be composed of an elastomeric material configured to defect, conform, deform or flex under force. The lip  90  may have a generally circular, oval, triangular, rectangular, square or higher order polygon shape. According to various examples, the lip  90  may have a substantially similar shape to a cross-sectional shape of the honeycomb body  14 . According to various examples, the lip  90  may have a perimeter larger than a perimeter of the filter  10  and/or honeycomb body  14 . In other words, the embossed features  82  and/or wells  94  may have a greater area than an area of an end surface of the filter  10 . One or more of the lips  90  may have a suitable shape and perimeter to seat around the perimeter of the filter  10  or a sufficiently large shape and perimeter such that a gap extends between the lip  90  and the perimeter of the honeycomb body  14 . It will be understood that in examples where the roller drum  78  includes a plurality of embossed features  82 , one or more of the lips  90  of the embossed features  82  may have a different shape or material composition than one or more of the other lips  90 . The lips  90  of the embossed features  82  may be raised, or proud, relative to the surface  86  of the roller drum  78  to define the well  94 . The lips  90  may have a height of from about 0.1 mm to about 50 mm relative to the surface  86  of the roller drum  78 . For example, the lips  90  may have a height of about 0.1 mm or greater, about 0.5 mm or greater, about 1 mm or greater, about 2 mm or greater, about 3 mm or greater, about 4 mm or greater, about 5 mm or greater, about 6 mm or greater, about 7 mm or greater, about 8 mm or greater, about 9 mm or greater, about 10 mm or greater, about 15 mm or greater, about 20 mm or greater, about 30 mm or greater, about 40 mm or greater or any and all values and ranges therebetween. 
     According to various examples, the surface  86  of the roller drum  78  within the embossed feature  82  may be lowered, or depressed, relative to the surface  86  exterior to the embossed feature  82 . For example, the surface  86  may be depressed into the roller drum  78 . As such, the well  94  may extend partially into the roller drum  78 . The depth of the surface  86  within the embossed feature  82 , relative to the surface  86  exterior to the embossed feature  82 , may be from about 0.1 mm to about 30 mm. For example, the depth of the surface  86  may be about 0.1 mm or greater, about 0.5 mm or greater, about 1 mm or greater, about 2 mm or greater, about 3 mm or greater, about 4 mm or greater, about 5 mm or greater, about 6 mm or greater, about 7 mm or greater, about 8 mm or greater, about 9 mm or greater, about 10 mm or greater, about 20 mm or greater, about 30 mm or greater or any and all values and ranges therebetween. In examples where the surface  86  of the embossed feature  82  is depressed into the roller drum  78 , the embossed feature  82  may omit or not include the lip  90 . 
     Next, a step  100  of moving the filter  10  (or a plurality of filters  10 ) over the roller drum  78  (i.e., which is rotating from the action of step  74 ) to define a nip  104  between the roller drum  78  and the filter  10  is performed. According to various examples, the filter  10  may be moved over the embossed features  82  of the roller drum  78  to define the nip  104  between the one or more embossed features  82  and the mask layer  58 . It will be understood that in high volume process runs of the method  50 , the plurality of filters  10  may be moved over the rotating roller drum  78  with each of the filters  10  aligned and synchronized with the movement of an embossed feature  82 . In such examples, the filters  10  may be supported by individual arms, a conveyor belt, or other structures to support the filters  10 . The filters  10  may be moved at a rate and speed such that a filter  10  is present as each of the embossed features  82  reaches a top of the roller drum  78 . Although depicted at a top of the roller drum  78 , it will be understood that the nip  104  may be formed at a variety of locations around the roller drum  78  and that multiple nips  104  may be formed. For example, filters  10  may be moved over or proximate a variety of locations of the roller drum  78  sequentially or simultaneously. 
     The nip  104  may have a thickness (i.e., a minimum distance between the mask layer  58  and the embossed feature  82  (e.g., the surface  86  within the embossed feature  82 )) of from about 0.01 mm to about 5 mm. For example, the nip  104  may have a thickness of about 0.01 mm, about 0.05 mm, about 0.1 mm, about 0.2 mm, about 0.3 mm, about 0.4 mm, about 0.5 mm, about 0.6 mm, about 0.7 mm, about 0.8 mm, about 0.9 mm, about 1.0 mm, about 2.0 mm, about 3.0 mm, about 4.0 mm, about 5.0 mm or any and all values and ranges therebetween. According to various examples, the thickness of the nip  104  may be different across the length of the embossed feature  82 . For example, the nip  104  defined between the center of the embossed feature  82  and the mask layer  58  may be greater or less than the nip  104  defined between a periphery of the embossed feature  82  and the mask layer  58 . Further, the thickness of the nip  104  may be changed (e.g., through movement of the roller drum  78  and/or filter  10 ) as the filter  10  is moving across the embossed feature  82 . 
     Next, a step  110  of inserting a plugging cement  114  in the nip  104  between the roller  78  drum and the mask layer  58  such that the roller drum  78  forces the plugging cement  114  through the plurality of holes  66  of the mask layer  58  into the plurality of channels  26  of the filter  10  is performed. Although described as separate steps for clarity, it will be understood that steps  100  and  110  may be performed substantially simultaneously such that the plugging cement  114  is inserted into the nip  104  formed by moving the filter  10  over the roller drum  78 . As the motion of the filters  10  and the roller drum  78  is synchronized such that the filters  10  are presented to the roller drum  78  to meet the embossed features  82 , step  110  may consist of inserting the plugging cement  114  in the nip  104  such that the one or more embossed features  82  forces the plugging cement  114  through the plurality of holes  66  of the mask layer  58  into the plurality of channels  26  of the filter  10 . 
     The plugging cement  114  is highly viscous and non-Newtonian in nature and may typically exhibit shear thinning. The plugging cement  114  may be composed of a clay, an inorganic binder, water and a plurality of inorganic particles. According to various examples, the plugging cement  114  may include one or more additives (e.g., rheology modifiers, plasticizers, organic binders, foaming agents, etc.). According to various examples, the clay may include one or more colloidal clays, smectite clays, kaolinite clays, illite clays, and chlorite clays. The inorganic binder may take the form of silica, alumina, other inorganic binders and combinations thereof. The silica may take the form of fine amorphous, nonporous and generally spherical silica particles. At least one commercial example of suitable colloidal silica for the manufacture of the plugging cement  114  may include Ludox®. The plurality of inorganic particles within the plugging cement  114  may be composed of glasses, ceramics, glass-ceramics, cordierite and/or combinations thereof. According to various examples, the plurality of inorganic particles may have the same or a similar composition to that of the honeycomb body  14 . For example, the plurality of inorganic particles may include cordierite and/or other materials which, upon sintering, form a porous structure. 
     Insertion of the plugging cement  114  into the nip  104  generates shear pressure within the plugging cement  114  such that the plugging cement  114  may thin, or decrease in viscosity, and pass through the holes  66  of the mask layer  58 . As the plugging cement  114  is inserted between the embossed feature  82  and the filter  10  and/or mask layer  84 , the plugging cement  114  is compressed under an increasing shear force as it reaches the nip  104 . As the filter  10  approaches the roller drum  78  from a direction which is offset from a tangent of the surface  86  of the roller drum  78  within the embossed feature  82 , the plugging cement  114  is forced into an increasingly small space as it approaches the nip  104 . As such, a shear pressure builds within the plugging cement  114  with the peak, or maximum, shear pressure occurring at the nip  104 . 
     The maximum shear pressure generated within the plugging cement  114  may be from about 1 psi to about 50 psi. For example the maximum shear pressure generated within the plugging cement  114  may be about 1 psi, about 2 psi, about 3 psi, about 4 psi, about 5 psi, about 6 psi, about 7 psi, about 8 psi, about 9 psi, about 10 psi, about 20 psi, about 30 psi, about 40 psi, about 50 psi or any and all values and ranges therebetween. The pressure generated in the plugging cement  114  is a function of the thickness of the plugging cement  114  and the thickness of the nip  104 . In general, the thicker the plugging cement  114  and the thinner the nip  104 , the more pressure is generated within the plugging cement  114 . As such, use of a thinner nip  104  or a thicker plugging cement  114  may generate greater shear pressures within the plugging cement  114 . 
     The shear pressure may be generated in the plugging cement  114  at a rate of from about 1 psi/s to about 50 psi/s. For example, the shear pressure generated within the plugging cement  114  at a rate of about 1 psi/s, about 2 psi/s, about 3 psi/s, about 4 psi/s, about 5 psi/s, about 6 psi/s, about 7 psi/s, about 8 psi/s, about 9 psi/s, about 10 psi/s, about 20 psi/s, about 30 psi/s, about 40 psi/s, about 50 psi/s or any and all values and ranges therebetween. The rate of shear pressure generation in the plugging cement  114  is a function of the speed of rotation of the roller drum  78  as well as the diameter of the roller drum  78 . For example, an increasing rotation rate of the roller drum  78  leads to an increased rate of shear pressure generation within the plugging cement  114  as the plugging cement  114  is forced into the nip  104  faster. Similarly, a decreased diameter of the roller drum  78  causes the surface  86  within the embossed feature  82  to converge to the nip  104  quicker (i.e., due to a lower radius of curvature) thereby increasing the rate at which the shear pressure is generated within the plugging cement  114 . As the diameter of the roller drum  78  increases, the shape of the converging region (e.g., the nip  104 ) changes. Such changes in the diameter of the roller drum  78  allow for a change in the pressure profile generated to accommodate line speed changes along with different rheological properties of materials used in the process. Such a feature may be advantageous in allowing a flexibility in the implementation of the method  50  by allowing a greater variability of other process parameters. 
     Step  110  of inserting the plugging cement  114  into the nip  104  may be carried out in a variety of manners. According to various examples, shown as steps  110 A and  110 B, the plugging cement  114  is inserted into the nip  104  on a carrier web  120 . In such an example, step  110  may include an action of conveying the plugging cement  114  along the carrier web  120  through the nip  104  between the embossed features  82  of the roller drum  78  and the mask layer  58  such that the embossed features  82  force the plugging cement  114  through the plurality of holes  66  of the mask layer  58  into the plurality of channels  26  of the filter  10 . The plugging cement  114  may be positioned on the carrier web  120  as a plurality of discontinuous, or discrete, portions (step  110 A) or as a single continuous portion (step  110 B). 
     The carrier web  120  may be formed of a polymeric material, elastomeric material, cloth material, fiber (e.g., natural and/or synthetic) material, metal, other materials and/or combinations thereof. According to various examples, the carrier web  120  may be configured to stretch and/or deform to an extent as it moves through the nip  104 . The carrier web  120  may be part of a larger conveying system incorporating or more rollers which move, wind and/or change directions of the carrier web  120 . The carrier web  120  may be a single continuous structure of a plurality of smaller carrier webs  120  coupled together. In such an example, the carrier web  120  may be continuously looped during operation of the method  50 . According to various examples, the carrier web  120  may be a discontinuous structure. In such an example, the carrier web  120  may be spooled off a roller and re-spooled onto another roller. At the end of the method  50 , the re-spooled carrier web  120  may be cleaned or reconditioned and reused for another run of the method  50 . As explained above, the carrier web  120  may carry or transport the plugging cement  114  to the nip  104  such that the plugging cement  114  is inserted in the nip  104  between the embossing features  82  and the mask layer  58 . 
     In the depicted example of step  110 A, the plugging cement  114  may be positioned on the carrier web  120  in a discontinuous or discrete manner. For example, the plugging cement  114  may be disposed as patties or portions on the carrier web  120 . The patties of plugging cement  114  may be circular, triangular, square, rectangular or higher order polygon shapes. It will be understood that one or more of the patties of plugging cement  114  may have a different shape than other patties of the plugging cement  114 . The patties of plugging cement  114  may have a thickness of from about 1 mm to about 20 mm. For example, the patties of plugging cement  114  may have a thickness of about 1 mm, about 2 mm, about 3 mm, about 4 mm, about 5 mm, about 6 mm, about 7 mm, about 8 mm, about 9 mm, about 11 mm, about 12 mm, about 13 mm, about 14 mm, about 15 mm, about 16 mm, about 17 mm, about 18 mm, about 19 mm, about 20 mm or any and all values and ranges therebetween. According to various examples, the patties of plugging cement  114  may have a shape and thickness substantially similar to that of the well  94  of the embossed feature  82 . Such a feature may be advantageous in allowing the entirety of the patty to be surrounded by the lip  90  and pressed into the filter  10  through the mask layer  58 . For example, the depressed surface  86  and/or the lip  90  may prevent the plugging cement  114  from being squeezed out of side of the nip  104  such that a greater amount of the plugging cement  114  enters the filter  10 . The plugging cement  114  may be dispensed as a metered mass or volume of cement  114  onto the carrier web  120  through a progressive cavity pump mounted on a traversing mechanism that deposits cement in a predetermined pattern onto the carrier web  120 . In other examples, the plugging cement  114  may be provided to the carrier web  120  in preformed patties such that the patties may be simply placed on the carrier web  120 . 
     In operation, movement of the carrier web  120  and the roller drum  78  may be synchronized such that the patties of the plugging cement  114  meet the nip  104  at the same time as an embossed feature  82  and the filter  10  reaches the nip  104 . In other words, as the patty of plugging cement  114  reaches the nip  104 , the roller drum  78  contacts the embossed feature  82  to the carrier web  120  on an opposite side of the carrier web  120  than the plugging cement  114  is positioned such that the lip  90  seats on the filter  10  and shear pressure builds within the plugging cement  114  to press the plugging cement  114  through the holes  66  of the mask layer  58  and into the channels  26  of the filter  10 . It will be understood that motion of the filter  10  which may generally resist the insertion of the plugging cement  114  into the filter  10  may be resisted by constraining the filter  10 . For example, movement of the filter  10  in a direction away from the roller drum  78  may be resisted such that the plugging cement  114  enters the channels  26 . According to various examples, the raised lip  90 , which may outline the circumference of the filter  10 , may form a seal between the plugging cement  114 , the carrier web  120  and the filter  10  that allows the shear pressure to build while preventing the leakage of the plugging cement  114  in an outward direction. 
     In the depicted example of step  110 B, the plugging cement  114  may be provided on the carrier web  120  as a single continuous body. It will be understood that while the plugging cement  114  may be continuous, the plugging cement  114  may vary in thickness or width as it is dispensed onto the carrier web  120 . For example, portions of the plugging cement  114  not expected to contact a filter  10  may be thinner or smaller. Such a feature may be advantageous in decreasing a waste of the plugging cement  114  and/or eliminating start and stop defects in the plugging cement  114  as it is placed on the carrier web  120 . According to various examples, the continuous portion of plugging cement  114  may be wider than the filter  10 . The plugging cement  114  may be dispensed onto the carrier web  120  through a progressive cavity pump mounted on a traversing mechanism that deposits cement in a substantially continuous manner onto the carrier web  120 . 
     In operation, movement of the carrier web  120  and the roller drum  78  may allow the embossed feature  82  to contact an opposite side of the carrier web  120  than the plugging cement  114  and press portions of the plugging cement  114  into the filter  10 . In other words, as the lip  90  of the embossed feature  82  seats on the filter  10 , the plugging cement  114  caught between the carrier web  120  and the filter  10  is pressed through the holes  66  in the mask layer  58  and into the channels  26 . It will be understood that in continuous examples of the plugging cement  114 , the lip  90  of the embossed feature  82  may not be necessary or may be smaller relative to other examples as the plugging cement  114 . For example, as the width of the plugging cement  114  on the carrier web  120  may be wider than the filter  10 , the excess plugging cement  114  may provide sufficient constraint on the plugging cement  114  to generate the requisite shear pressure in the plugging cement  114  without the lip  90  needing to seat around the filter  10 . Excess plugging cement  114  may be removed from the carrier web  120  (e.g., through a blade, scraper or other method) and recycled to be reapplied to the carrier web  120 . 
     According to various examples, the carrier web  120  may be omitted in an example  110 C of step  110 . In such an example, the wells  94  of the embossed features  82  may be filled with the plugging cement  114  such that contact between the embossed feature  82  and the filter  10  presses the plugging cement  114  through the mask layer  58 . In other words, step  110 C may include the action of positioning the plugging cement  114  within the well  94  of the embossed feature  82 . The plugging cement  114  may be positioned within the well  94  in a variety of manners. In a first example, a preformed patty or portion of plugging cement  114  may be placed into the well  94 . For example, the patty of plugging cement  114  may have generally the same proportions as the well  94 , or the patty may be larger. In examples where the patty is larger than the well  94 , the lip  90  may sever the excess plugging cement  114  as the patty is placed over the embossed feature  82 . According to yet other examples, the plugging cement  114  may be dispensed directly into the wells  94  of the embossed features  82 . In such examples, the plugging cement  114  may be dispensed from an exterior of the roller drum  78  and/or from an interior of the roller drum  78 . In exterior examples, one or more dispensing nozzles may be positioned proximate the roller drum  78  and configured to dispense the plugging cement  114  into the wells  94  as the roller drum  78  is rotated. In interior filling examples, the surface  86  within the well  94  may define a plurality of slits or openings to an interior of the roller drum  78 . A dispensing nozzle (e.g., a slot die nozzle) may be positioned within the roller drum  78  such that as the slits of the surface  86  pass over the dispensing nozzle, plugging cement  114  is extruded from the dispensing nozzle through the slits in the surface  86  and into the well  94  of the embossed features  82 . 
     Next, a step  130  of stripping the mask layer  58  from the filter  10  is performed. Once the filter  10  has passed by the roller drum  78  and the plugging cement  114  has been pushed into the channels  26 , the carrier web  120  and mask layer  58  may be directed over a roller or other device that provides a constant or variable stripping angle to separate the mask layer  58  and the carrier web  120  from the filter  10 . The diameter of the stripping roller can be adjusted to vary the stripping angle. It will be understood that the carrier web  120  and the mask layer  58  may be stripped in separate steps by separate rollers without departing from the teachings provided herein. Once the carrier web  120  is stripped from the filter  10 , excess plugging cement  114  positioned on the carrier web  120  may be removed and recirculated as explained above. Further, if the mask layer  58  is adhered to the carrier web  120 , the mask layer  58  may be stripped from the carrier web  120 . 
     Once the mask layer  58  and the carrier web  120  have been stripped from the filter  10 , the plugging cement  114  located in the plurality of channels  26  may be sintered, fired or otherwise cured. The fired plugging cement  114  within the channels  26  forms the plugs  30  such that the filter  10  may be used to filter fluids such as liquids and gases as outlined above. 
     Use of the roller drum  78  to press the plugging cement  114  into the filters  10  offers a continuous process to form the plugs  30  within the filter  10 . Further, as the rate of rotation of the roller drum  78 , as well as the speed at which the plugging cement  114  is fed to the nip  104 , may be variably controlled (e.g., increased or decreased), the method  50  may offer a wide variety of production rates of the filters  10 . As the method  50  may employ a variety of techniques to quickly deliver the plugging cement  114  to the nip  104  shortly after formation or dispensing of the plugging cement  114 , changes in rheological properties of the cement  114  may be discounted. Conventional techniques of plugging wall flow filters often suffer from changes in rheological properties which affect plug formation quality (e.g., depth, porosity, variability, etc.) due to long lead times between dispensing of the plugging cement  114  and application to the filter  10 . As the method  50  has a short time frame between dispensing of the plugging mixture  114  (e.g., onto the carrier web  120  and/or into the well  94 ), plug quality is improved. As the diameter of the roller drum  78  may be changed, the flow rate of the plugging cement  114  into the plurality of channels  26  may be adjusted. Such a feature may be advantageous in controlling quality and variability of the resulting plugs  30 . As a number of process variables (e.g., size of the nip  104 , the diameter of the roller drum  78 , the rotation speed of the roller  78 ) may be changed, a variety of plugging cements  114  which have different rheological properties may be utilized offering greater process flexibility. Use of the lip  90  of the embossed features  82  may allow for an increased shear pressure to build within the plugging cement  114  such that shallow or smaller channels  26  near a periphery of the filter  10  may be filled. Such features as thickness, durometer and shape of the lips  90  may be controlled to improve the uniformity as increased leak prevention of the plugging cement  114  may be obtained. As a metered amount of plugging cement  114  is delivered to the nip  104 , less waste plugging cement  114  may be realized as compared to conventional methods of forming wall flow filters  10 . Such a feature may be advantageous in decreasing both production costs as well as manufacturing complexity of the forming the filters  10 . As the method  50  includes a plurality of different variables (e.g., diameter of the roller drum  78 , rheological properties plugging cement  114 , initial profile (e.g., patty shape, thickness, continuous vs. discrete) of the plugging cement  114 , rotation speed of the roller drum  78 ), the method  50  can be optimized based on a variety of considerations allow for less waste and more uniform filters  10 . 
     Modifications of the disclosure will occur to those skilled in the art and to those who make or use the disclosure. Therefore, it is understood that the embodiments shown in the drawings and described above are merely for illustrative purposes and not intended to limit the scope of the disclosure, which is defined by the following claims, as interpreted according to the principles of patent law, including the doctrine of equivalents. 
     It will be understood by one having ordinary skill in the art that construction of the described disclosure, and other components, is not limited to any specific material. Other exemplary embodiments of the disclosure disclosed herein may be formed from a wide variety of materials, unless described otherwise herein.