Method of plugging a honeycomb body

An apparatus for plugging honeycomb bodies includes a controller configured to signal a plugging actuator to move a plugging piston from the predetermined start position to an extended position while a shutter plate is in an open orientation, wherein at least about 50% of the predetermined volume of plugging material is discharged from a dispensing area during a single plugging cycle. The controller is still further configured to signal a control actuator of a plugging material control module to adjust a position of a control piston within a control chamber to maintain a pressure of the plugging material within the dispensing area from between greater than 0 psi to about 200 psi when the shutter plate is moved between a closed orientation and the open orientation at the beginning of the plugging cycle. Further examples include methods of plugging a honeycomb body with a plugging material control module.

FIELD

The present disclosure relates generally to apparatus for plugging honeycomb bodies and methods, and more particularly, to apparatus including a plugging material control module for plugging honeycomb bodies and methods.

BACKGROUND

FIG. 1is a conventional illustration of a honeycomb body102prior to selected cells being sealed by a plugging material. The honeycomb body102is typically fabricated with a matrix of intersecting, thin, porous walls104surrounded by an outer wall106, which in the illustrated example is provided a circular cross-sectional configuration. The walls104extend across and between a first end face108and a second end face112. The matrix of intersecting, thin, porous walls104define corresponding channels110that define hollow passages extending between the first end face108and the second end face112.

Conventional methods are known to seal one end of each of the channels110such that a first subset of channels are sealed at the first end face108and the second subset of channels are sealed at the second end face112.

In operation, contaminated fluid (e.g., exhaust gas including particulate matter, such as exhaust soot) can be brought under pressure to an inlet face and enters the plugged honeycomb body102through one of the two subsets of channels that are open to an inlet face of the filter. Because this subset of channels is sealed at the opposite end face, i.e., the outlet face of the body, the contaminated fluid is forced through the thin porous walls104and into adjoining cell channels of the other of the two subset of channels that are open to the outlet face of the filter. As the fluid is forced through the porous walls104, solid particulate entrained in the fluid can be filtered out such that a clean fluid stream eventually exits the outlet face of the filter.

FIG. 2is a schematic view of a conventional apparatus202similar to the apparatus described in U.S. Patent Application Publication No. 2006/0131782, published Jun. 22, 2006. As shown, the apparatus includes a source204of pressurized plugging material. A valve206can be selectively opened to charge a plugging chamber212with a quantity of plugging material sufficient to carry out multiple plugging cycles.

FIG. 3is a schematic view of a conventional skinning apparatus250including a conventional skinning control module260. The skinning apparatus250is configured to supply skinning material from a source252of skinning material to apply the outer wall106to the periphery of the honeycomb body102. The source252can include a skinning material reservoir254and a pump256configured to operate under the instruction of a controller258. The skinning control module260includes a skinning piston262configured to reciprocate within a cylindrical portion264by a piston actuator263. A conical extension266provides a fluid connection between the cylindrical portion264and a skinning material supply line268. The skinning control module260also includes an upstream valve270and a downstream valve272.

In operation, as shown inFIG. 4, the controller (i.e.,258inFIG. 3) can open the upstream valve270and close the downstream valve272. As shown inFIG. 5, the pump (i.e.,256inFIG. 3) can then by activated to fill a skinning chamber274with skinning material from the source (i.e.,252inFIG. 3) of skinning material. As shown inFIG. 6, the controller can then close the upstream valve270and open the downstream valve272. As shown inFIG. 7, the piston actuator263can then extend the skinning piston262in direction276such that the skinning material is passed through the conical extension266and into the supply line268. As shown inFIG. 7, the conical section houses residual skinning material outside of the supply line268even when the skinning piston262is in the fully extended position.

Turning back toFIG. 3, operation of the control module260, as discussed with respect toFIGS. 4-7, does not directly regulate pressure of the skinning material280but allows control of the flow rate that skinning material280is dispensed by nozzle278. At the desired dispensing flow rate, skinning material280may be adequately and efficiently applied to the surface of the honeycomb body102for subsequent smoothing by a doctor blade282as the honeycomb body102rotates about axis284.

SUMMARY

In one aspect, a method of plugging a honeycomb body comprises the steps of providing a source of plugging material in fluid communication with a plugging material control module and providing a plugging device. The plugging device includes a plugging chamber in fluid communication with the source of plugging material and the plugging chamber includes a wall with a first plurality of apertures. The plugging device also includes a shutter plate including a second plurality of apertures, and a plugging piston configured to reciprocate within the plugging chamber. The method further includes the step of moving the shutter plate to a closed orientation wherein the second plurality of apertures are not aligned with the first plurality of apertures and are blocked by the wall of the plugging chamber. The method further includes the step of moving the plugging piston to a predetermined start position relative to the shutter plate within the plugging chamber with plugging material being added into the dispensing area from the source of plugging material until a predetermined volume of plugging material is charged in the dispensing area defined between the plugging piston and the wall of the plugging chamber. The method further includes the step of moving the shutter plate to an open orientation wherein the first plurality of apertures are aligned with the second plurality of apertures. The method also includes the step of moving the plugging piston from the predetermined start position to an extended position while the shutter plate is in the open orientation such that at least about 50% of the predetermined volume of plugging material is discharged from the dispensing area to plug the honeycomb body during a single plugging cycle. The method further includes the step of operating the plugging material control module to maintain a pressure of the plugging material within the dispensing area from between greater than 0 psi to about 200 psi when the shutter plate is moved between the closed orientation and the open orientation at the beginning of the plugging cycle.

In another aspect, an apparatus for plugging honeycomb bodies comprises a source of plugging material in fluid communication with a supply line and a plugging material control module. The plugging control module includes a control chamber in fluid communication with the supply line at a first location downstream from the source of plugging material. The plugging control module further includes a control piston configured to reciprocate within the control chamber. The plugging control module also includes a control actuator configured to adjust the position of the control piston within the control chamber. The apparatus further includes a plugging device including a plugging chamber in fluid communication with the supply line at a second location downstream from the first location, the plugging chamber including a wall with a first plurality of apertures. The plugging device also includes a shutter plate including a second plurality of apertures. The shutter plate actuator is configured to move the shutter plate relative to the wall of the plugging chamber between an open orientation with the first plurality of apertures aligned with the second plurality of apertures and a closed orientation with the second plurality of apertures not aligned with the first plurality of apertures and blocked by the wall of the plugging chamber. The plugging device also includes a plugging piston configured to reciprocate within the plugging chamber and a plugging actuator configured to adjust the position of the plugging piston within the plugging chamber. The apparatus further includes a controller configured to signal the shutter plate actuator to orient the shutter plate in the closed orientation and signal the plugging actuator to move the plugging piston to a predetermined start position with respect to the shutter plate within the plugging chamber with plugging material being added into a dispensing area defined between the plugging piston and the wall of the plugging chamber until a predetermined volume of plugging material is charged into the dispensing area. The controller is also configured to signal the shutter plate actuator to orient the shutter plate in the open orientation after the predetermined volume of plugging material is charged into the dispensing area. The controller is also configured to signal the plugging actuator to move the plugging piston from the predetermined start position to an extended position while the shutter plate is in the open orientation such that at least about 50% of the predetermined volume of plugging material is discharged from the dispensing area during a single plugging cycle. The controller is further configured to signal the control actuator to adjust the position of the control piston within the control chamber to maintain a pressure of the plugging material within the dispensing area from between greater than 0 psi to about 200 psi when the shutter plate is moved between the closed orientation and the open orientation at the beginning of the plugging cycle.

DETAILED DESCRIPTION

The present invention will now be described more fully hereinafter with reference to the accompanying drawings in which example embodiments of the claimed invention are shown. Whenever possible, the same reference numerals are used throughout the drawings to refer to the same or like parts. However, the claimed invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. These example embodiments are provided so that this disclosure will be both thorough and complete, and will fully convey the scope of the claimed invention to those skilled in the art.

Honeycomb structures having traverse cross-sectional cellular densities of approximately ten to one hundred cells or more per square centimeter have several uses, including solid particulate filter bodies and stationary heat exchangers. Wall flow particulate filter applications require selected cells of the structure to be sealed or plugged at one or both of the respective ends thereof. The term “sealed” and other corresponding grammatical forms, i.e., sealant, sealing, etc., are used herein to refer to porous and non-porous methods of closing the open traverse cross-sectional areas of the cells. The plugging material used to seal the honeycomb body can comprise a wide range of materials. In one example, the plugging material can comprise a material that forms ceramic plugs upon firing, although other plugging materials may be provided in further examples.

FIG. 8illustrates one schematic example of an apparatus302configured to plug a honeycomb body102. The honeycomb body102may be formed from a wide variety of materials including ceramics, glass-ceramics, glasses, metals, and by a variety of methods depending upon the material selected. For example, the honeycomb body102can have uniform thin, porous and interconnected walls for solid particulate filtering applications may be fabricated from plastically formable and sinterable finely divided particles of substances that yield a porous, sintered material after being fired to effect their sintering. Suitable materials include metallics, ceramics, glass-ceramics, and other ceramic based mixtures. One example method of forming such a ceramic honeycomb monolith from an extruded cordierite material is described and claimed in U.S. Pat. No. 5,258,150 which is herein incorporated by reference in its entirety.

Certain components of the apparatus302may be similar or identical to the apparatus described in U.S. Patent Application Publication No. 2006/0131782, published Jun. 22, 2006 that is herein incorporated by reference in its entirety. The apparatus302includes a source304of plugging material306. In one example, the source304can comprise a reservoir of nonpressurized batch material although the batch material may be pressurized within the reservoir in further examples. For instance, as shown, the source304comprises a reservoir308in fluid communication with a pump310configured to pump batch material to a plugging chamber312of a plugging device303. In alternative embodiments, the source304can comprise a reservoir that may be pressurized by a gas, piston, and/or auger arrangement.

As shown inFIGS. 9-11, the plugging chamber312can, at least in part, be formed by a passage314defined within a body316of the apparatus302. In one example, the passage can comprise a cylindrical shape, such as the illustrated circular cylindrical shape. In further examples, the passage may comprise other cylindrical shapes such as elliptical, polygonal or other cross sectional shapes. Moreover, at least an extent of the passage314can have substantially the same cross sectional shape along the extent. Moreover, the cross sectional shape of the passage314can be geometrically similar to the periphery of a plugging piston318to allow the piston to reciprocate within the plugging chamber312. As shown in the illustrated example, the plugging piston318may have an outer periphery320with a circular shape that is geometrically similar to the inner circular peripheral shape of the passage314. The outer periphery320can also include a peripheral seal322configured to seal against the inner peripheral surface of the passage314to provide a barrier for plugging material306within the plugging chamber312.

As shown, one axial portion of the plugging chamber312can be closed by a face324of the plugging piston318. The other axial portion of the plugging chamber312can be selectively opened and closed by a shutter plate340interacting with a wall330of the plugging chamber312. The wall330can be integral with the body316. In further examples, the wall330can be separate from the body316and selectively attached to the body316. For instance, the wall330can be clamped with respect to the body316in a manner that allows the shutter plate340to reciprocate between an open orientation and a closed orientation with respect to the wall330. The wall330can include a first plurality of apertures332with a wide range of patterns that can each have the same or different shapes and sizes.

As shown, the shutter plate340can include a second plurality of apertures342that may be selectively brought into alignment or out of alignment with the first plurality of apertures332. As shown, the shutter plate is positioned such that blocking portions344of the shutter plate340are positioned within the plugging chamber312. In further examples, the shutter plate can be positioned on the other side of the apertures332of the wall330such that the blocking portions344of the shutter plate340are positioned outside of the plugging chamber312.

As shown inFIG. 9, the shutter plate may be moved in direction346relative to the wall330to the illustrated closed orientation. In the closed orientation, the second plurality of apertures342of the shutter plate340are not aligned with the first plurality of apertures332of the wall330. Indeed, the closed orientation is achieved since misalignment of the apertures allows blocking portions344of the shutter plate340to block the corresponding apertures of the wall330. At the same time, in the closed orientation, the second plurality of apertures342are blocked by the wall330of the plugging chamber312. As such, in the closed orientation, the plugging chamber312is substantially fluid tight, thereby providing a sealed dispensing area313configured to receive and hold a predetermined volume of plugging material306for subsequent dispensing to seal a corresponding first subset of the channels110of the honeycomb body102with a desired depth having limited variability across the face of the honeycomb body102.

As shown inFIG. 10, the shutter plate340may be moved in an opposite direction348to the illustrated open orientation wherein the first plurality of apertures332of the wall330are aligned with the second plurality of apertures342of the shutter plate340. As shown inFIG. 11, in the open orientation, the plugging piston318may be moved in direction349to substantially discharge at least a quantity of the plugging material306out of the plugging chamber312by passing through the aligned apertures332,342.

Turning back toFIG. 8, the apparatus302further includes a plugging control module402including a control chamber404in fluid communication with a supply line406at a first location407downstream from the source304of plugging material306. As further illustrated inFIG. 8, the plugging chamber312of the plugging device303is also placed in fluid communication with the supply line406at a second location412downstream from the first location407. In some examples, it can be desirable to minimize the distance between the first location407and the second location412to help achieve better control of the plugging material passing between the control chamber404and the plugging chamber312.

It can be desirable to provide communication between the supply line406and the plugging chamber in a way that allows communication to be maintained after a full extension of the plugging piston from the predetermined start position shown inFIG. 10to the extended position inFIG. 11. For example, referring toFIG. 11, the piston is in the fully extended position wherein the face324is in close proximity to the wall330to dispense substantially the entire predetermined volume of plugging material within the dispensing area313. As further illustrated inFIG. 11, in the fully extended position, the face324may come very close or even abut the shutter plate340(or the wall330). Even in the fully extended position, the supply line406is in communication with the face324of the plugging piston318, for example, by passing through a port319axially extending through the plugging piston318from a rear portion to the face324of the plugging piston318. In further examples, the port may be located in the body316and communicating with the passage314immediately next to the shutter plate340(or wall330). As such, even in the fully extended position illustrated inFIG. 11, the supply line406may communicate with an interface between the face324of the piston and the shutter plate340(or wall330), allowing plugging material to be fed at that location to again fill the plugging chamber312as the plugging piston moves back to the predetermined start position shown inFIG. 9. In further examples, the piston may be extended at slightly less or less than the fully extended position. For example, as shown, the piston can be extended substantially the entire stroke length of the piston reciprocating within the chamber. In some examples, the stroke length may be ½ an inch, ¼ an inch, or other stroke lengths between the fully extended position shown inFIG. 11and the fully retracted position shown inFIGS. 9 and 10. In further examples, the piston may be extended 30% of the stroke length, such as 40%, 50%, 75%, 90%, 95% or 98% of the stroke length in further examples.

Referring back toFIG. 8, the plugging control module402can also include a control piston408configured to reciprocate within the control chamber404and a control actuator410configured to adjust the position of the control piston408within the control chamber404. As shown inFIGS. 14 and 15, a structure can define a control passage414that can include a cylindrical shape, such as the illustrated circular cylindrical shape. In further examples, the control passage414may comprise other cylindrical shapes such as elliptical, polygonal or other cross sectional shapes. Moreover, at least an extent of the control passage414can have substantially the same cross sectional shape along the extent. Moreover, the cross sectional shape of the control passage414can be geometrically similar to the periphery of the control piston408to allow the control piston to reciprocate within the control passage414. As shown in the illustrated example, the control piston408may have an outer periphery411with a circular shape that is geometrically similar to the inner circular peripheral shape of the control passage414. The outer periphery411can also include a peripheral seal416configured to seal against the inner peripheral surface of the control passage414to provide a barrier for plugging material306within a control chamber418(seeFIG. 20).

As shown inFIG. 16, the supply line406may comprise a conduit with an internal surface420with a substantially circular profile although noncircular profiles may be provided in further examples. For instance, although not shown, the supply line406may comprise an elliptical, polygonal or other cross-sectional profile shapes. As shown inFIG. 15, the face of the control piston408can optionally have a surface422that complements a remaining surface426of a portion424of the supply line406at the first location407. For example, as shown inFIG. 15, the surface422has a profile along a cross section perpendicular to a flow path428of the supply line406that extends along a first arc of a circle. Likewise, the remaining surface426has a profile along a cross section perpendicular to the flow path428of the supply line406that extends along a second arc of the same circle. As shown inFIG. 15, the control piston408can therefore be moved to a fully extended position wherein the first arc and second arc cooperate with one another to define a substantially continuous interior circle profile that can be substantially identical to the circle profile downstream of the control passage414as shown inFIG. 16. Therefore, as illustrated, the outer cross sectional profile of the control piston408may optionally substantially match an inner cross-sectional profile of the supply line406such that substantially no plugging material is retained in the control chamber404when the control piston408is in the fully extended position as shown inFIGS. 14 and 15. Although a circular shape is illustrated, it will be appreciated that the face of the piston can have other surface shapes that cooperate with the remaining surface of the portion of the supply line. As such, when the piston is in the fully extended position, the interior profile of the face of the piston in combination with the remaining portion of the supply line can be substantially identical to a profile of the supply line located downstream of the control passage414.

Turning back toFIG. 8, the plugging control module402can also include an upstream valve430and a downstream valve432that may each be placed in communication with a controller434. The controller434is schematically represented with a first portion434aand a second portion434balthough the controller may include a single portion or more than two portions in further examples. In one example, the controller434is configured to send signals along respective control lines to the valves430,432to selectively orient the valves430,432in an open or closed orientation.

The controller434can also send a signal along a corresponding control line to signal a shutter plate actuator442to orient the shutter plate340in the closed orientation illustrated inFIGS. 8 and 9. The controller434can also send a signal along the corresponding control line to signal the shutter plate actuator442to orient the shutter plate340in the open orientation illustrated inFIGS. 10 and 11after plugging material is added to the dispensing area313until a predetermined volume of plugging material is charged into the dispensing area313.

The controller434may also send a signal along a control line to a plugging actuator440to signal the plugging actuator440to adjust the position of the plugging piston318within the plugging chamber312. The controller434can signal the plugging actuator440to move the plugging piston318to a predetermined start position (shown inFIG. 9) with respect to the shutter plate within the plugging chamber such that a predetermined volume of plugging material from the supply line is charged into a dispensing area313defined between the plugging piston318and the wall330of the plugging chamber312. Likewise, the controller can signal the plugging actuator440to move the plugging piston318from the predetermined start position (shown inFIG. 9) to a fully extended position (shown inFIG. 11) while the shutter plate340is in the open orientation, wherein substantially an entire predetermined volume of plugging material is discharged from a dispensing area313during a single plugging cycle.

The controller434can also signal the control actuator410to adjust the position of the control piston408within the control chamber404to maintain a pressure of the plugging material306within the dispensing area313from between greater than 0 psi to about 200 psi, such as between about 20 psi to about 200 psi, such as between about 20 psi to about 100 psi, such as about 20 psi to about 50 psi, when the shutter plate340is moved between the closed orientation and the open orientation at the beginning of a plugging cycle.

The apparatus302may include various pressure transducers in communication with the controller434to facilitate methods of plugging the honeycomb body. For example, a first pressure transducer450may be designed to send a pressure signal to the controller434corresponding to the pressure applied by the control actuator410. A second pressure transducer452may also be included to send a pressure signal to the controller434corresponding to the pressure of the plugging material306within the portion424of the supply line406. A third pressure transducer454may be provided to send a pressure signal to the controller434corresponding to the pressure of the plugging material306within the supply line406downstream from the plugging control module402, such as near or within the dispensing area313. A fourth pressure transducer456can also be provided to send a pressure signal to the controller434corresponding to the pressure applied by the plugging actuator440to the plugging piston318.

As shown inFIG. 8, an optional transparent or translucent mask458may be adhered to the first end face108of the honeycomb body102. In further examples another optional mask (not shown) may be provided on the second end face112. In some examples, the apparatus302can include a volume460of plugging material positioned within an optional pre-plugging chamber462that may be defined in the wall330of the apparatus302. As shown, the wall330may be provided as a first clamping portion configured to be clamped with a second clamping portion464. Both clamping portions can cooperate to removably clamp an outer portion466of the mask458.

The outer portion466of the mask458extends radially outward from an outer edge114of the honeycomb body102. The mask458can extend radially outward from the outer edge114while a central portion of the mask458is adhered to the first end face108. In one example, the mask458extends about 1 inch (2.54 cm) past the outer edge114of the honeycomb body102but, in the illustrated example, can extend to any distance sufficient to allow secure clamping of the outer portion466.

The pre-plugging chamber462, if provided, can have a shape that generally approximates the shape of the first end face108of the honeycomb body102. For instance, the pre-plugging chamber462can have a round, oval, polygonal or other shape that is geometrically similar to the first end face108of the honeycomb body102. The volume460of plugging material in the pre-plugging chamber462can be sufficient for one or more plugging cycles. In one example, the volume460of plugging material is sufficient for a single plugging cycle. In further examples, the volume460of plugging material is less than the volume necessary for a single plugging cycle. In still further examples, aspects of the disclosure may be practiced without a pre-plugging chamber. In certain examples, reducing the volume of the pre-plugging chamber can be desirable to reduce residence time of plugging material within the pre-plugging chamber or other parts of the apparatus to provide more consistency in the plugging material being used to plug the selected channels of the honeycomb body102. In one example, the volume460of plugging material in the pre-plugging chamber462is substantially uniform in thickness to minimize the effects of compressibility of the plugging material. As such, the ends of the selected channels may be sealed with plugs having substantially uniform depth within the honeycomb body102.

In one example, the pre-plugging chamber462, if provided, can have a depth which is approximately ½ inch (1.27 cm). Alternatively, the pre-plugging chamber462can have any depth that is large enough to insure sufficient plugging material306flow such that the entire cross-sectional area is filled. Also, the pre-plugging chamber462may be small enough to minimize slumping of the plugging material306if the honeycomb body is plugged in a horizontal orientation (as illustrated inFIG. 8). Slumping can occur due to the liquid nature of the plugging material306. When the apparatus302is opened while loading the new honeycomb body302, there may be nothing holding the plugging material306in the pre-plugging chamber462. As such, a slump may form in the surface468of the plugging material306in the pre-plugging chamber462.

Methods of plugging a honeycomb body will now be described with the illustrative apparatus302. The method can include the step of loading the honeycomb body102into the plugging device303. The plugging device303can then move the honeycomb body102laterally until the mask458abuts a surface468of the volume460of plugging material within the pre-plugging chamber462. The wall330, acting as a first clamping portion, can then be clamped against the second clamping portion464to clamp the outer portion466of the mask therebetween.

The method can further include the step of moving the shutter plate340to a closed orientation (shown inFIG. 9) wherein the second plurality of apertures342of the shutter plate340are not aligned with the first plurality of apertures332of the wall330and are blocked by the wall330of the plugging chamber312. The plugging piston318can then be moved from an extended position, such as the fully extended position illustrated inFIG. 11, to a predetermined start position relative to the shutter plate (illustrated inFIG. 9). The predetermined start position can comprise substantially the same location for each plugging cycle. The start position can be monitored in a wide range of ways. For example, as shown inFIG. 8, a proximity sensor470may provide a signal to the controller434to sense the position of the plugging piston318and therefore allow accurate positioning of the plugging piston318at substantially the same location during each subsequent plugging cycle. As shown, the proximity sensor470may be integrated as part of the plugging actuator440although the proximity sensor may be provided as a separate sensor in further examples. Repeatedly locating the plugging piston318at substantially the same predetermined start position can be effective to allow the dispensing area313to be charged to substantially the same volume of plugging material at the beginning of each plugging cycle. As such, the plug depth can be maintained substantially consistent at each end face of a plurality of honeycomb bodies during subsequent plugging cycles.

As shown inFIG. 9, once the plugging piston318is accurately retracted to the predetermined start position relative to the shutter plate340within the plugging chamber312, plugging material can be added to the dispensing area313from the source304of plugging material until a predetermined volume of plugging material is charged in the dispensing area313defined between the plugging piston318and the wall330of the plugging chamber312.

As shown inFIG. 10, the shutter plate340can then be moved to an open orientation wherein the first plurality of apertures332of the wall330are aligned with the second plurality of apertures342of the shutter plate340. The plugging piston318can then be moved from the predetermined start position to an extended position while the shutter plate340is in the open orientation such that at least about 50%, such as at least about 75%, such as at least about 90%, such as at least about 95% of the predetermined volume of plugging material is discharged from the dispensing area313to plug the honeycomb body during a single plugging cycle. As shown inFIG. 11, optionally, the plugging piston318can then be moved from the predetermined start position to a fully extended position while the shutter plate340is in the open orientation such that substantially the entire predetermined volume of plugging material is discharged from the dispensing area313to plug the honeycomb body102during a single plugging cycle. Dispensing at least 50%, 75%, 90%, 95% or substantially all of the plugging material from the dispensing area313can be beneficial to avoid changes in viscosity of the material that may otherwise occur with substantial residual times between plugging cycles. As such, each plugging cycle fills the plugging chamber312with a fresh quantity of plugging material that can have a substantially consistent viscosity throughout the dispensing area313. A substantial quantity of the predetermined volume (e.g., at least 50%) can then be consumed during a single plugging cycle. In one example, the remainder of plugging material within the plugging chamber312is not sufficient to conduct a subsequent plugging cycle without recharging the plugging chamber312to the predetermined volume of plugging material. As such, new plugging material can be introduced into the plugging chamber312after each plugging cycle.

The method of plugging can further include the step of operating the plugging material control module402to maintain a pressure of the plugging material within the dispensing area313from between greater than 0 psi to about 200 psi, such as between about 20 psi to about 200 psi, such as between about 20 psi to about 100 psi, such as about 20 psi to about 50 psi, when the shutter plate340is moved between the closed orientation (seeFIG. 9) and the open orientation (seeFIG. 10) at the beginning of the plugging cycle. Such control of the pressure of the plugging material within the dispensing area313can prevent voids from occurring within the dispensing area and can minimize uncontrolled flow of plugging material due to expansion when the shutter plate opens. As such, proper control of the pressure of the plugging material within the dispensing area313(e.g., between greater than 0 psi to about 200 psi, such as between about 20 psi to about 200 psi, such as between about 20 psi to about 100 psi, such as about 20 psi to about 50 psi) can result in a controlled sealing process providing plug depth with reduced variability along the corresponding end face.

For example,FIGS. 12 and 13show a honeycomb body102after the end face has been sealed with plugs472that extend from the first end face108at a distance “D” that can be substantially the same for all of the plugs472. A desired minimum target plug depth sufficient to effectively seal the ends of the channels can be achieved without overshooting a substantial number of the channels with plugs having unnecessarily long depths. The minimum target depth can allow sufficient bonding between the honeycomb body channels and the plugs to avoid plug blow out or other plug failure throughout the product life cycle. Moreover, avoiding overshooting the minimum target depth can provide more effective filtering area of the porous walls104, thereby increasing engine performance and fuel economy as soot accumulates. Moreover, increasing the effective filtering area of the porous walls104can require less frequent regeneration cycles for the honeycomb filter. As such, plugs472can be provided with a sufficient, consistent and predictable depth at the desired distance “D”. The plugs472can therefore be provided with a depth that has reduced variability across the sealed face of the honeycomb body and reduced variability between the average depth between sealed ends of a plurality of honeycomb bodies. As such, during subsequent sealing operations for other honeycomb bodies can effectively seal the set of channels110at the first end face (e.g., in the checkerboard fashion shown inFIG. 12) while maximizing effective filtering surface area for the porous walls104.

In still further examples, the pressure of the plugging material306within the dispensing area313can be maintained substantially constant when the shutter plate340is moved between the closed orientation and the open orientation at a beginning of the plugging cycle. Maintaining the pressure at a substantially consistent level can further control the sealing process and provide plugs472at a desired target depth “D” with reduced variability along the corresponding end face of the honeycomb body.

The plugging chamber312can be charged with the desired volume of plugging material in a wide range of ways. Two examples are described more fully below. In the first example, the plugging chamber312can be charged directly by action of the pump310of the source304of plugging material. The controller can activate the control actuator410such that the control piston408is fully extended position shown inFIG. 14. In the fully extended position, substantially no plugging material is contained within the control chamber418. As shown inFIG. 14, the controller can also close the upstream valve430and open the downstream valve432. If more plugging material is needed to move the plugging piston318to the predetermined start position, the controller opens upstream valve430as shown inFIG. 17. As further illustrated inFIG. 17, the downstream valve432is maintained in the open orientation and the control piston408is maintained in the fully extended position. Then the pump310is activated to supply plugging material to the plugging chamber312until the plugging piston318reaches the predetermined start position.

As shown inFIG. 18, once the plugging piston318reaches the predetermined start position, the upstream valve430is closed. The control piston408can then be reciprocated (indicated by directional arrow474) within the control chamber to maintain the pressure of the plugging material within the dispensing area313from between greater than 0 psi to about 200 psi (as discussed above) when the shutter plate is moved between the closed orientation and the open orientation at the beginning of the plugging cycle.

In the second example, the plugging chamber312can be charged by action of the plugging control module402. For example, the control piston408can be moved to a fully extended position shown inFIG. 18with the upstream valve430closed and the downstream valve432open. As shown inFIG. 19, if more plugging material is needed to move the plugging piston318to the predetermined start position, the controller opens the upstream valve430and closes the downstream valve432. The pump310can then be activated to supply plugging material to the control chamber418. As shown inFIG. 20, the pump310continues to supply plugging material to fill the control chamber418with a predetermined volume of plugging material from the source of plugging material. The volume of plugging material can be predetermined based on the amount of material necessary to provide the plugging chamber with the desired predetermined volume of plugging material. The volume of the plugging material within the control chamber418can be calculated based on a sensed position of the control piston408.

As shown inFIG. 21, once the desired volume of plugging material is received by the control chamber418, the controller can close the upstream valve430and open the downstream valve432. As shown inFIG. 22, the control piston408can then be moved from the predetermined start position (shown inFIG. 21) to a fully extended position (shown inFIG. 22) such that substantially the entire volume of plugging material is discharged from the control chamber418to the fluid supply line406. Discharging the entire volume of the plugging material from the control chamber418can be designed to fully charge the dispensing area313of the plugging apparatus302with the plugging piston318located in the predetermined start position. Moreover, as illustrated inFIG. 15, substantially no residual plugging material is left in the control chamber418when the piston is in the fully extended position. As such, substantially all of the plugging material can be forced into the supply line406to thereby minimize residence time of plugging material that may otherwise exist if substantially all of the plugging material was not forced out of the control chamber418when fully extending the control piston408.

As shown inFIG. 18, the control piston408can then be reciprocated (indicated by directional arrow474) within the control chamber to maintain the pressure of the plugging material within the dispensing area313from between greater than 0 psi to about 200 psi (as discussed above) when the shutter plate is moved between the closed orientation and the open orientation at the beginning of the plugging cycle.

As shown inFIG. 11, the plugging piston318is then fully extended along direction349to seal the corresponding subset of channels110. Turning back toFIG. 8, once the honeycomb body102is sealed, a cutting member350, such as the illustrated wire, can be used to cut the plugging material to again form the surface468of the volume460of plugging material for the next plugging cycle. The second clamping portion464can then be released relative to the wall330acting as the first clamping portion to release the outer portion466of the mask458. The mask458can then be removed to leave the plugs472behind at the desired depth described with respect toFIG. 13.