Apparatus and method for coating a substrate with a washcoat

Abstract

An apparatus and method for coating a substrate with a washcoat. The apparatus and method for coating a substrate (110) with a washcoat includes: engaging the substrate with a headset (6) of a substrate-coating apparatus (100) so that an upper surface of the substrate is positioned below a washcoat showerhead of the substrate-coating apparatus; discharging a washcoat from the washcoat showerhead toward the upper surface of the substrate; and drawing the washcoat through the substrate by applying suction to a lower surface of the substrate. The step of engaging the substrate with the headset includes engaging a headset seal (115) of the headset with the substrate, the headset seal (115) having a peripheral portion (116) extending around the headset and a cantilever portion (117) extending downward from the peripheral portion that engages a sidewall of the substrate.

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE This disclosure relates to an apparatus and method for coating a substrate with a washcoat, and in particular, it relates to coating a substrate used for exhaust gas purification. [Background technology]

[0002] Substrates for exhaust gas purification typically include a monolith substrate provided with passages for the throughflow of exhaust gas. The substrate can be provided with a coating, which can be a catalytic coating. The coating can be applied to the substrate as a washcoat that passes through the passages in the substrate. Various methods are known for applying a coating to a substrate. One such method includes applying a washcoat to a first side (e.g., top side) of the substrate and exposing an opposite second side (e.g., bottom side) of the substrate to at least a partial vacuum to achieve movement of the washcoat through the passages. After coating, the substrate can be dried and calcined.

[0003] The substrate can be configured as a flow-through substrate, with each passage open on both the first and second sides of the substrate, and the passages extending through the entire length of the substrate. As a result, exhaust gases entering a passage through the first side of the substrate travel through the substrate in the same manner until they exit the second side of the substrate. Alternatively, the substrate can be configured as a filter substrate, with some passages plugged on the first side of the substrate and other passages plugged on the second side of the substrate. In such a configuration, exhaust gases entering a first passage through the first side of the substrate flow along the first passage partway along the substrate before passing through the filtering wall of the substrate and entering a second passage. The exhaust gases then travel along the second passage and exit the second side of the substrate. This arrangement has become known in the art as a wall-flow filter.

[0004] The coated flow-through substrate may comprise a three way catalyst (TWC), a selective catalytic reduction (SCR) catalyst, a diesel oxidation catalyst (DOC), a lean NOx trap catalyst (LNT), an ammonia slip catalyst (ASC), a combined selective catalytic reduction catalyst and ammonia slip catalyst (SCR / ASC), or a passive NOx adsorber (PNA).

[0005] The coated filter substrate can be, for example, a catalyzed soot filter (CSF) with an oxidation catalyst, a selective catalytic reduction filter (SCRF) with a selective catalytic reduction catalyst (SCR), a lean NOx trap filter (LNTF) with a NOx adsorber composition, a gasoline particulate filter (GPF) with a three-way catalyst composition, or a filter substrate with a selective catalytic reduction (SCR) catalyst and an ammonia slip catalyst (ASC).

[0006] The substrate may be made of or consist of a ceramic or metallic material, for example, aluminum titanate, cordierite (SiO2-AI2O3-MgO), silicon carbide (SiC), Fe—Cr—AI alloy, Ni—Cr—AI alloy, or stainless steel alloy.

[0007] The substrate generally has a substrate body with a uniform cross-sectional shape along its longitudinal length. Typically, the substrate body may have a circular or nearly circular cross-section, although other cross-sectional shapes, such as square and rectangular, are possible. The upper surface of the substrate body may be defined as the surface positioned uppermost during coating, and similarly, the lower surface of the substrate body may be defined as the surface positioned lowermost during coating. Generally, the upper and lower surfaces are planar and perpendicular to the longitudinal axis of the substrate body.

[0008] Some specialized substrates may be provided with non-planar upper and / or lower surfaces. For example, the upper surface may be provided with a groove or notch for receiving another component. For example, a sensor of an emissions control system may, in use, be positioned within the groove or notch when the substrate is assembled into the emissions control system. In another example, the upper surface may be dome-shaped, concave or convex, covering part or all of the surface.

[0009] When coating a substrate, it may typically be desirable to achieve a substantially "flat" washcoat profile, i.e., a "tip" or "leading edge" of the washcoat that is substantially flat or perpendicular to the longitudinal axis of the passage (marking a boundary interface between coated and uncoated portions of the substrate).

[0010] Applying a washcoat to a substrate having a non-planar upper or lower surface has been found to present particular problems. Washcoat applied to the upper surface may preferentially collect or pool in the grooves or notches. This can lead to difficulties in precisely controlling the distribution of the washcoat as a vacuum is drawn into the substrate body, and in particular in achieving a substantially flat washcoat profile. For example, when the washcoat is subsequently drawn through the substrate, the substrate may acquire an undulating, i.e., non-flat, washcoat profile. This can occur, for example, because a larger volume of washcoat covers the grooves or notches and is thus sucked further into the substrate body in the areas underlying the grooves or notches. An undulating washcoat profile can have a detrimental effect on the operating efficiency of the substrate. For example, the undulating profile can lead to portions of the substrate not being coated (reducing the catalytic efficiency of the substrate) or portions of the substrate being unintentionally coated more than once—multiple doses of washcoat being applied—which can detrimentally increase the backpressure on the substrate. In some situations, the washcoat may be pulled completely through the substrate body and emerge from the lower surface, which can lead to wasted washcoat and even potential blockage of passage openings on the lower surface of the substrate.

[0011] Alternatively or additionally, there may be problems in adequately sealing the substrate body to prevent loss of the washcoat down the sides of the substrate body. This may be a particular problem when grooves or notches extend to the sidewalls of the substrate body. Staining of the sidewalls of the substrate with the washcoat may also lead to visual degradation of the substrate, obscuring visual identification marks that may be provided on the sidewalls of the substrate, such as, for example, a tracking barcode.

[0012] Alternatively or additionally, even when the substrate has a planar upper surface, there may be problems in achieving greater spreading of the washcoat across the upper surface of some substrates. For example, for a given substrate, there may be a viscosity threshold at which the washcoat is absorbed into the passages too quickly and does not spread adequately or evenly across the upper surface. This may lead to an increased amount of washcoat entering the passages directly below the washcoat outlet, which may result in an undulating washcoat profile. Summary of the Invention

[0013] In a first aspect, the present disclosure provides a method of coating a substrate with a washcoat, the method comprising: - engaging the substrate with a headset of the substrate coating apparatus to position the upper surface of the substrate under a washcoat showerhead of the substrate coating apparatus; - disposing a partition between the washcoat showerhead and an upper surface of the substrate, the partition having a plurality of holes and positioned within the headset to maintain a first gap between a lower surface of the partition and the upper surface of the substrate; - dispensing a washcoat from a washcoat showerhead onto the top surface of the partition; - forcing the washcoat through the holes in the partition onto the upper surface of the substrate and into the substrate, at least in part by applying suction to the lower surface of the substrate.

[0014] In a second aspect, the present disclosure provides a substrate coating apparatus, the substrate coating apparatus comprising: a source of washcoat; a washcoat showerhead for dispensing the washcoat toward an upper surface of the substrate; a conduit fluidly connecting a source of washcoat to the washcoat showerhead for delivering the washcoat to the washcoat showerhead; a head set for engaging the substrate so as to position an upper surface of the substrate under the washcoat showerhead; a vacuum generator for sucking the washcoat discharged from the washcoat showerhead through the substrate; The headset includes a partition having a plurality of holes, the partition being disposed between the washcoat showerhead and the upper surface of the substrate when the substrate is engaged with the headset so as to maintain a first gap between a lower surface of the partition and the upper surface of the substrate.

[0015] In a third aspect, the present disclosure provides a substrate coating system comprising a substrate coating apparatus and a substrate of the above aspect, wherein an upper surface of the substrate is non-planar and, optionally, the upper surface of the substrate comprises a feature, e.g., a groove or notch, that extends to a sidewall of the substrate, thereby defining a gap in the sidewall.

[0016] In a fourth aspect, the present disclosure provides a divider configured for use in a substrate coating apparatus, the divider comprising a disk-shaped body; the disc-shaped body has a thickness between an upper surface of the disc-shaped body and a lower surface of the disc-shaped body of 5 to 15 mm, optionally 7.5 to 12.5 mm, optionally 10 mm; the partition comprises more than 500 holes, optionally more than 1000 holes, optionally more than 1500 holes, optionally more than 2000 holes; the holes are each 1-3 mm in diameter, optionally 2 mm in diameter; The open area of ​​the partition, defined as the percentage of the total area of ​​the top surface of the partition that is comprised by holes, is 35-55%, optionally 40-50%, optionally about 45%.

[0017] Advantageously, in any of the above aspects, the use of the partition having multiple holes helps prevent the washcoat from accumulating in, for example, grooves or notches in the upper surface of the substrate when the upper surface is non-planar, which has been found to result in reduced adverse effects on the washcoat profile and reduced pull-through of the washcoat from the lower surface of the substrate.

[0018] In particular, in any of the above embodiments, the suction force can be advantageously applied within a certain time limit while the washcoat is being dispensed onto the upper surface of the partition. For example, this time limit can be 5 seconds, preferably 3 seconds, and more preferably 1 second. This can advantageously limit or prevent the washcoat from reaching the upper surface of the substrate before the suction force is applied. In this way, the washcoat in contact with the upper surface of the substrate can be immediately sucked into the substrate body by the applied suction force, thereby preventing or at least substantially reducing pooling or accumulation of the washcoat in any grooves or notches in the upper surface.

[0019] Additionally, in any of the above embodiments, maintaining a first gap between the lower surface of the partition and the upper surface of the substrate advantageously helps minimize and / or prevent washcoat connection between the partition and the substrate before or after suction force is applied to the lower surface of the substrate, for example, by preventing any capillary action between the partition and the upper surface of the substrate.

[0020] Any one of the first to fourth aspects may also include one or more of the following features. A divider may be disposed in fixed relationship within the headset. The first gap can be 2-7 mm, optionally 5 mm. Accordingly, the first gap can be optimized not only to minimize or prevent washcoat merging, but also to control and / or limit further spread of the washcoat. For example, the configuration of the washcoat showerhead can be selected to achieve a desired initial distribution of the washcoat on the top surface of the partition. Therefore, it can be desirable not to make the first gap too large; otherwise, the washcoat may be subject to further unwanted disturbances, such as from mixing of the separate streams, splashing, splashing, etc. Accordingly, a first gap of 2-7 mm has been found to be most effective. The partition may be disk-shaped and may have a thickness between the upper surface of the partition and the lower surface of the partition of 5 to 15 mm, optionally 7.5 to 12.5 mm, optionally 10 mm. It has been found advantageous to limit the thickness of the partition to 5 to 15 mm in order to minimize additional back pressure on the substrate coating system. The divider may be positioned within the headset to maintain a second gap of 80-130 mm between the underside of the washcoat showerhead and the top surface of the divider. A distance of 80-130 mm has been found to optimize the distribution of the washcoat onto the top surface of the divider when deposited by the washcoat showerhead. The partition may comprise more than 500 holes, optionally more than 1000 holes, optionally more than 1500 holes, optionally more than 2000 holes. The holes may each be 1-3 mm in diameter, optionally 2 mm in diameter. The open area of ​​the partition, defined as the percentage of the total area of ​​the top surface of the partition that is constituted by the holes, may be 35-55%, optionally 40-50%, optionally about 45%. Thus, advantageously, the partition may be optimized to minimize or prevent seepage of the washcoat through the partition onto the top surface of the substrate until suction is applied, while limiting additional backpressure on the system and providing good distribution of the washcoat throughout the partition, and therefore across the top surface of the substrate. The headset may further include a headset seal, and the divider may be disposed within the headset above the headset seal. As mentioned, the upper surface of the substrate may be non-planar. Additionally, the top surface of the substrate may include features, such as grooves or notches, that extend to the sidewall of the substrate, thereby defining a gap in the sidewall. The substrate may be selected from a flow-through substrate (e.g., a monolithic flow-through substrate) or a filter substrate (e.g., a wall-flow filter substrate). The washcoat may comprise a catalytic coating selected from a three-way catalyst (TWC), a selective catalytic reduction (SCR) catalyst, a diesel oxidation catalyst (DOC), a lean NOx trap catalyst (LNT), an ammonia slip catalyst (ASC), a combined selective catalytic reduction catalyst and ammonia slip catalyst (SCR / ASC), or a passive NOx adsorber (PNA). · The washcoat can have a viscosity of 3-9000 cP.

[0021] In a fifth aspect, the present disclosure provides a method of coating a substrate with a washcoat, the method comprising: - engaging the substrate with a headset of the substrate coating apparatus to position the upper surface of the substrate under a washcoat showerhead of the substrate coating apparatus; - dispensing a washcoat from a washcoat showerhead toward an upper surface of a substrate; - sucking the washcoat through the substrate by applying suction to the lower surface of the substrate; The step of engaging the substrate with the headset includes engaging a headset seal of the headset with the substrate, the headset seal having a peripheral portion extending around the headset and a cantilever portion extending downwardly from the peripheral portion that engages a sidewall of the substrate.

[0022] In a sixth aspect, the present disclosure provides a substrate coating apparatus, the substrate coating apparatus comprising: a source of washcoat; a washcoat showerhead for dispensing the washcoat toward an upper surface of the substrate; a conduit fluidly connecting a source of washcoat to the washcoat showerhead for delivering the washcoat to the washcoat showerhead; a head set for engaging the substrate so as to position an upper surface of the substrate under the washcoat showerhead; a vacuum generator for sucking the washcoat discharged from the washcoat showerhead through the substrate; The headset comprises a headset seal for engaging the substrate, the headset seal comprising a peripheral portion extending around the headset and a cantilever portion extending downwardly from the peripheral portion and configured to engage a sidewall of the substrate.

[0023] In a seventh aspect, the present disclosure provides a headset seal for engaging a substrate, the headset seal comprising: a peripheral portion for extending around the headset; and a cantilever portion extending from the peripheral portion and configured to engage a sidewall of the substrate.

[0024] Any one of the fifth to seventh aspects may also include one or more of the following features. The peripheral portion may comprise an annular portion, optionally a circular portion or an oval portion, extending all around the headset. The cantilevered portion may be arc-shaped. The cantilevered portion may have an arc length of 105-300% of the arc length of the sidewall gap, optionally 105-200% of the arc length of the sidewall gap. The cantilevered portion subtends a central angle of 45 to 120°, optionally 65 to 75°, optionally 45 to 90°. The cantilevered portion may extend at an angle of 0-15° to a plane normal to the peripheral portion, optionally at an angle of 0-10° to a plane normal to the peripheral portion, optionally at an angle of about 3° to a plane normal to the peripheral portion. Engaging the substrate with the headset allows the cantilevered portion of the headset seal to flex substantially radially. The lower edge of the cantilevered portion may be free to protrude and thus be able to flex substantially radially. The cantilevered portion may engage a region of the sidewall of the substrate having a height at least 5 mm greater than the depth of the gap in the sidewall of the substrate. The cantilevered portion may extend downwardly at least 20mm below the lower surface of the peripheral portion, optionally at least 30mm below the lower surface of the peripheral portion, optionally at least 40mm below the face rim of the peripheral portion. The peripheral portion and the cantilever portion may be integrally formed or may be separate. The peripheral portion and the cantilever portion may be formed of different materials. At least the cantilevered portion may be made from a flexible material. The cantilevered portion may have a Shore hardness of 35A to 45A, optionally 40A. The headset may include a rigid headset frame that supports a peripheral portion of the headset seal, and the cantilevered portion of the headset seal may extend below a lower surface of the rigid headset frame. The lower edge of the cantilevered portion may protrude freely from the rigid headset frame. The upper surface of the substrate may be non-planar. The top surface of the substrate may include a feature, e.g., a groove or notch, that extends to the sidewall of the substrate, thereby defining a gap in the sidewall, and the cantilevered portion fills the gap to prevent the washcoat from leaking through the gap and causing the sidewall of the substrate to drop. The substrate may be selected from a flow-through substrate (e.g., a monolithic flow-through substrate) or a filter substrate (e.g., a wall-flow filter substrate). The washcoat may comprise a catalytic coating selected from a three-way catalyst (TWC), a selective catalytic reduction (SCR) catalyst, a diesel oxidation catalyst (DOC), a lean NOx trap catalyst (LNT), an ammonia slip catalyst (ASC), a combined selective catalytic reduction catalyst and ammonia slip catalyst (SCR / ASC), or a passive NOx adsorber (PNA).

[0025] The features of the first to fourth aspects may be combined with the features of the fifth to seventh aspects, and vice versa. For example, a substrate coating apparatus may be provided with a partition according to the second aspect and a head set seal according to the sixth aspect.

[0026] All references to viscosity herein refer to the viscosity of a fluid as measured using a Brookfield rotational viscometer fitted with a Small Sample Adaptor and a link hanging spindle, with the sample temperature controlled at 25° C. Such a viscometer is available from Brookfield Engineering Laboratories, Inc., Middleboro, MA, USA.

[0027] All measurements were taken in 14 seconds. -1 As is common knowledge to those skilled in the art, the spindle, rotation speed, and viscometer model were selected depending on the viscosity of the fluid to ensure that the percent viscometer torque has a minimum measurement value greater than 10% and a maximum measurement value less than 100%, but if this is not possible, the percent viscometer torque may have a minimum measurement value greater than 0% and a maximum measurement value less than 100%. For the viscosity measurements herein, the following spindles were used: The viscosity range of 3-100 cP was measured in an LV viscometer using spindle SC4-18 at 10.6 rpm. The viscosity range of 100-500 cP was measured in an LV viscometer using spindle SC4-28 at 50 rpm. The viscosity range of 500-9000 cP was measured in an RV viscometer using spindle SC4-28 at 50 rpm. [Brief explanation of the drawings]

[0028] Aspects and embodiments of the present disclosure will now be described, by way of example only, with reference to the accompanying drawings, in which: [Figure 1] 1 is a schematic cross-sectional view of a substrate coating apparatus. [Figure 2] FIG. 2 is a schematic enlarged view of a portion of FIG. [Figure 3] FIG. [Figure 4] FIG. 4 is a schematic diagram showing a substrate of the type shown in FIG. 3 in a portion of a substrate coating apparatus. [Figure 5] FIG. 1 is a bottom perspective view of a headset seal for a substrate coating apparatus. [Figure 6] FIG. 6 is a plan view from below of the headset seal of FIG. 5. [Figure 7] FIG. 6 is a side elevational view of the headset seal of FIG. 5. [Figure 8] FIG. 6 is a cross-sectional view of the headset seal of FIG. [Figure 9] 6 is a photograph of a portion of a substrate coating apparatus incorporating a head set seal of the type shown in FIG. 5. [Figure 10] 1 is a cross-sectional view of a portion of a substrate coating apparatus incorporating a divider. [Figure 11] FIG. 11 is a perspective view from above of the partition of FIG. 10. [Figure 12] FIG. 11 is a plan view from above of the partition of FIG. 10. [Figure 13] FIG. 11 is a side elevation view of the partition of FIG. 10. [Figure 14] FIG. 2 is a side view of a substrate after coating with a washcoat. [Figure 15] FIG. 2 is a plan view of a portion of a substrate after coating with a washcoat. [Figure 16]FIG. 1 is a side view of a cross-sectioned substrate after coating with a washcoat. [Figure 17] FIG. 17 is a bottom view of the substrate of FIG. 16 before cutting. DETAILED DESCRIPTION OF THE INVENTION

[0029] As used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "a catalyst" includes a mixture of two or more catalysts, and the like.

[0030] As used herein, the term "about" is inclusive of the specific value. For example, "about 45%" means about 45%, and also includes 45% within its meaning.

[0031] Those skilled in the art will recognize that one or more features of one aspect or embodiment of the present disclosure may be combined with one or more features of any other aspect or embodiment of the present disclosure, unless the immediate context teaches otherwise.

[0032] FIG. 1 shows a schematic cross-sectional view of a non-limiting example of a substrate coating apparatus 1 that can be used to coat a substrate 10 with a washcoat.

[0033] The substrate coating apparatus 1 may include a depositor 2 having a housing 40 containing an apparatus for activating a distribution mechanism. As shown, the distribution mechanism may include a piston 41 axially movable within a bore 42 to move fluid out an outlet 43 toward a conduit 35 disposed downstream of the depositor 2.

[0034] The substrate coating apparatus 1 may further include a hopper 3 defining a hopper reservoir 30 having an outlet 31 that connects with an outlet 43 of the depositor 2 through a diaphragm valve 32. The hopper 3 may be filled with a washcoat that has been formulated and premixed elsewhere. The washcoat may be pumped into the hopper reservoir 30 or may be gravity fed into the hopper reservoir 30 through a suitable conduit.

[0035] An outlet 43 of the depositor 2 is fluidly connected to a conduit 35, which in turn may extend in fluid communication with the metering valve 4. A washcoat showerhead 5 may be connected to the underside of the metering valve 4 with the washcoat showerhead 5 positioned above the substrate 10.

[0036] The substrate 10 may be positioned between the headset 6 and the pallet insert 8. A vacuum device including a vacuum cone 7 may be positioned below the substrate 10.

[0037] FIG. 2 shows an enlarged portion of the substrate coating apparatus 1 of FIG. 1, showing in more detail how the substrate 10 may be positioned relative to the washcoat showerhead 5 and headset 6.

[0038] 1 and 2 show a substrate 10 of the type having a substrate body 11 with a uniform cross-sectional shape along its longitudinal length. Typically, the substrate body 11 may have a circular or nearly circular cross-section. The substrate body 11 may be positioned to extend between the headset 6 and the pallet insert 8, with an upper surface 12 of the substrate body 11 at the top and a lower surface 13 of the substrate body 11 at the bottom. The upper and lower surfaces 12, 13 are planar and perpendicular to the longitudinal axis of the substrate body 11.

[0039] The headset 6 may include a headset seal 15 that engages an upper edge circumscribing the upper surface 12 of the substrate body 11. The headset seal 15 may include an annular ring that extends around the entire circumference of the headset 6.

[0040] The washcoat showerhead 5 may be positioned above the headset 6 and preferably aligned with the headset 6 and the substrate 10 so that the central longitudinal direction x of the washcoat showerhead 5 coincides with the central longitudinal axis of both the headset 6 and the substrate body 11, as shown in FIG. 2.

[0041] The washcoat showerhead 5 may include a showerhead housing 21 to which a showerhead plate 23 may be attached at its underside using bolts 26. An adapter plate 27 may be attached to the upper side of the showerhead housing 21, also using bolts 28.

[0042] The showerhead housing 21 may include a centrally located opening that defines an inlet 22 to a showerhead cavity 24 defined between the showerhead housing 21 and the showerhead plate 23. The axis of the inlet 22 may be coincident with the longitudinal axis x. The adapter plate 27 may also include a centrally located opening that may be sized to receive the central portion 20 of the showerhead housing 21 coincident with the longitudinal axis x. The metering valve 4 may be fluidly connected to and retained in the inlet 22 of the showerhead housing 21.

[0043] The showerhead plate 23 may be provided with an array of nozzle openings 25 .

[0044] In use, diaphragm valve 32 is opened and washcoat is drawn from hopper reservoir 30 into bore 42 by piston movement to the right (as viewed in FIG. 1 ). Diaphragm valve 32 is then closed and a charge of washcoat is then moved through conduit 35 by the action of depositor 2 piston 41 moving to the left (as viewed in FIG. 1 ). The washcoat passes through metering valve 4 and inlet 22 into showerhead cavity 24. The washcoat then passes through nozzle opening 25 and drops into contact with upper surface 12 of substrate 10. The washcoat then flows down through passages in substrate 10. The drawing of washcoat through substrate 10 is driven at least in part by suction applied to lower surface 13 of substrate 10 by vacuum cone 7.

[0045] 3 shows a substrate 110 having a substrate body 111 with an upper surface 112, a lower surface 113, and a sidewall 108. An upper edge 107 extends around the upper surface 112. The illustrated substrate 110 is generally cylindrical in shape with a single cylindrical sidewall 108. However, the substrate 110 can take other forms, such as an oval, a square with one or more, e.g., four, sidewalls, or a rectangular upper surface.

[0046] The upper surface 112 is provided with a groove or notch 114, hereinafter referred to for simplicity as "groove 114." Groove 114 may take on numerous shapes or forms and may be of various lengths. Groove 114 may be shaped and sized to fully or partially receive another component, for example a sensor of an emissions control system.

[0047] The groove 114 results in a non-planar upper surface 112. The groove 114 may extend across the entire diameter of the upper surface 112. Alternatively, as shown in FIG. 3, the groove 114 may extend across a portion of the diameter of the upper surface 112. The groove 114 may extend into the sidewall 108 at one or both of its ends to define one or more gaps 109 in the sidewall 108 and one or more discontinuities in the upper edge 107. As shown in FIG. 3, a single gap 109 is provided.

[0048] Groove 114 can have a variety of cross-sectional shapes when cut perpendicular to its length. Groove 114 in FIG. 3 has a semicircular cross-sectional shape. However, other shapes can be used depending on the shape of the component to be accommodated by groove 114. Gap 109 can have substantially the same shape as groove 114.

[0049] 4 illustrates a particular embodiment of the present disclosure, in which a portion of a substrate coating apparatus 100 according to the present disclosure has been modified, as compared to coating apparatus 1, to advantageously allow for coating of substrates having non-planar upper and / or lower surfaces. The substrate coating apparatus 100 is described merely as an example for coating the substrate 110 of FIG. 3. However, this is not intended to be limiting, and it will be understood that the substrate coating apparatus 100 may be beneficially used to coat other substrates.

[0050] Features of the substrate coating apparatus 100 that are the same as or substantially the same as the substrate coating apparatus 1 of Figures 1 and 2 are referred to by like reference numerals, e.g., 1 and 101, 10 and 110, and will not be described in further detail. Reference shall be made to the above description.

[0051] However, the headset seal 115 of the substrate coating apparatus 101 differs from the headset seal 15 of the substrate coating apparatus 1 shown in FIG.

[0052] In particular, as shown in Figures 5-8, the headset seal 115 comprises a peripheral portion 116 for extending around the headset 106 and a cantilevered portion 117 extending from the peripheral portion 116 and configured to engage the sidewall 108 of the substrate 110.

[0053] 6 and 7, the peripheral portion may preferably be circular or oval in shape, with an annular portion extending completely around the headset 106 when worn therein. The peripheral portion 116 may define a central opening 120 surrounded by an inner edge 121. The inner edge 121 may be perpendicular to the plane of the peripheral portion 116. Alternatively, the inner edge 121 may be shouldered, chamfered, or tapered, as desired.

[0054] The cantilevered portion 117 may be disposed at or adjacent to the inner edge 121 of the peripheral portion 116. The cantilevered portion 117 may be arc-shaped. This may be particularly useful when the sidewall 108 of the substrate 110 is cylindrical. The cantilevered portion 117 may subtend a central angle of 45 to 120°, optionally 65 to 75°, and optionally 45 to 90°. The cantilevered portion 117 may alternatively or additionally have an arc length that is 105 to 300% of the arc length of the gap 109 in the sidewall 108, optionally 105 to 200% of the arc length of the gap 109 in the sidewall 108.

[0055] Cantilevered portion 117 may extend downwardly at least 20 mm below the lower surface of peripheral portion 116, optionally at least 30 mm below the lower surface of peripheral portion 116, and optionally at least 40 mm below the face rim of peripheral portion 116.

[0056] As can be seen in Figures 6 and 8, the cantilevered portion 117 may have a radial depth of 2.5 to 5.0 mm.

[0057] As shown most clearly in FIG. 8, cantilevered portion 117 may extend at an angle of 0 to 15 degrees relative to a plane perpendicular to peripheral portion 116, optionally at an angle of 0 to 10 degrees relative to a plane perpendicular to peripheral portion 116, and optionally at an angle of about 3 degrees relative to a plane perpendicular to peripheral portion 116.

[0058] Although peripheral portion 116 and cantilever portion 117 are preferably integrally formed, they may be formed separately and then mounted together within headset 106 .

[0059] The peripheral portion 116 and the cantilevered portion 117 may be formed of different materials, for example, different co-molded materials, however, it may be preferable for them to be formed from a single material.

[0060] At least the cantilevered portion 117 may be formed from a flexible material. The peripheral portion 116 and / or the cantilevered portion 117 may be formed from a material having a Shore hardness of 35A to 45A, optionally 40A. The peripheral portion 116 and / or the cantilevered portion 117 may be formed from rubber, elastomer, or other sealing material. Non-limiting examples of suitable materials are silicone rubber and EPDM, such as silicone rubber with a Shore hardness of 40 and EPDM with a Shore hardness of 40.

[0061] As shown in FIG. 4, headset seal 115 is mounted within headset 106. Peripheral portion 116 may extend completely around the circumference of headset 106. Cantilevered portion 117 is shown extending downwardly from peripheral portion 116. A lower edge 123 of cantilevered portion 117 may be free to protrude from the frame of the headset and thus may be able to flex substantially radially, as most clearly shown in the photograph of FIG. 9 (which also shows features of divider 200, described further below).

[0062] By engaging the substrate 110 with the headset 106—which may allow the substrate 110 to engage and be lifted by the headset 106—the cantilevered portion 117 of the headset seal 115 may flex substantially radially to accommodate the passage of the substrate 110. Both the flexibility of the cantilevered portion 117 and the limited arc length of the cantilevered portion 117 may assist in easier and more reliable engagement of the substrate 110 and the headset 106 during substrate lifting. Thus, some tolerance for lateral misalignment of the substrate 110 and the headset 106 may be accommodated and accommodated by flexing the cantilevered portion 117.

[0063] Additionally or alternatively, angling the cantilevered portion 117 at an angle of 0-15° relative to a plane perpendicular to the peripheral portion 116 may also assist in easier and more reliable engagement of the substrate 110 with the headset 106 during substrate lifting. Thus, some tolerance for lateral misalignment of the substrate 110 with the headset 106 may be allowed for and accommodated by angling the cantilevered portion 117.

[0064] 4, groove 114 is shown engaging substrate 110 within headset 106. Peripheral portion 116 may sealingly engage top edge 107 of substrate 110. This engagement may be with inner edge 121 of peripheral portion 116.

[0065] The cantilevered portion 117 may engage a region of the sidewall 108 of the substrate 110. As shown in Figure 4, the cantilevered portion 117 preferably fills the gap 109 to prevent the washcoat from leaking out of the gap 109 and down the sidewall 108 of the substrate. The cantilevered portion 117 may have a height that is at least 5 mm greater than the depth of the gap 109 in the sidewall 108 of the substrate 110.

[0066] As mentioned above, cantilevered portion 117 may have an arc length that is 105-300% of the arc length of gap 109 in sidewall 108, optionally 105-200% of the arc length of gap 109 in sidewall 108. In this manner, tolerance to some angular misalignment of substrate 110 may be achieved, i.e., because cantilevered portion 117 is still long enough to fill and completely seal gap 109.

[0067] During operation of the substrate coating apparatus 101, a vacuum cone is used to apply suction to the lower surface of the substrate 110. Advantageously, the flexibility and / or relative thinness of the cantilevered portion 117 allows the cantilevered portion to be "sucked" into more firmly engaged engagement with the sidewall 108 by the suction force. This increases the reliability of the seal between the cantilevered portion 117 and the substrate 110.

[0068] During operation of the apparatus shown in FIG. 4 , similar to substrate-coating apparatus 1, washcoat passes through metering valve 104 and inlet 122 and enters showerhead cavity 124. The washcoat then passes through nozzle opening 125 and drops into contact with upper surface 112 of substrate 110. The washcoat then flows down through passages in substrate 110. Suction of the washcoat through substrate 110 is driven, at least in part, by suction applied by vacuum cone 7 to lower surface 113 of substrate 110. During this process, some washcoat may accumulate and pool within groove 114. The washcoat may flow along groove 114. However, the seal provided by cantilevered portion 117 above gap 109 prevents or substantially reduces any leakage of washcoat from gap 109 and downward movement of sidewall 108.

[0069] 10 illustrates a particular embodiment of the present disclosure in which a substrate coating apparatus is provided with a divider 200 interposed between a washcoat showerhead and an upper surface of a substrate. Hereinafter, the divider 200 is described, by way of example only, as part of the substrate coating apparatus 101 shown in FIGS. 4-9. The divider 200 may be used in other substrate coating apparatuses. However, as explained above, particularly beneficial effects may be achieved when the divider 200 is used in combination with a headset seal 115 having a cantilevered portion 117.

[0070] As shown most clearly in Figures 11-13, the divider 200 includes a body 205 with a plurality of holes 202. The body 205 may be disc-shaped and may have an upper surface 204 and a lower surface 203. The body 205 in Figure 12 is circular. However, the divider 200 may be other shapes and may be adapted to fit the size and shape of a particular headset.

[0071] The divider 200 may have a thickness between the top surface 204 of the divider 200 and the bottom surface 203 of the divider 200 of 5 to 15 mm, optionally 7.5 to 12.5 mm, optionally 10 mm.

[0072] The divider 200 may comprise more than 500 holes 202, optionally more than 1000 holes 202, optionally more than 1500 holes 202, optionally more than 2000 holes 202. The holes 202 may each be 1-3 mm in diameter, optionally 2 mm in diameter. The holes 202 may be arranged in a regular pattern or may be arranged stochastically.

[0073] The open area of ​​the partition 200, defined as the percentage of the total area of ​​the top surface 204 of the partition 200 that is comprised by holes 202, may be 35-55%, optionally 40-50%, optionally about 45%.

[0074] The divider 200 can be positioned between the washcoat showerhead 105 and the upper surface 112 of the substrate 110 when the substrate 110 is engaged with the headset 106 to maintain a first gap between the lower surface 203 of the divider 200 and the upper surface 112 of the substrate 110. The first gap can be 2 to 7 mm, optionally 5 mm.

[0075] Additionally or alternatively, the divider 200 can be positioned within the headset 106 to maintain a second gap between the underside of the washcoat showerhead 105 and the upper surface 204 of the divider. The second gap can be between 80 and 130 mm.

[0076] Preferably, the divider 200 is fixedly disposed within the headset 106 so that it is held stationary relative to the housing of the headset 106 .

[0077] The divider 200 may be made of metal, plastic, or other rigid material. Non-limiting examples of suitable materials include polyvinyl chloride (PVC), acetal, nylon 66, and Accura 25.

[0078] As shown in FIG. 10, the divider 200 is preferably disposed within the headset 106 above the headset seal 115 .

[0079] In use, the substrate coating apparatus 101 incorporating the divider 200 may be used in a method of coating a substrate 110 with a washcoat, the method comprising: - engaging the substrate 110 with the headset 106 to position the upper surface 112 of the substrate 110 under the washcoat showerhead 105 of the substrate coating apparatus 101; - disposing a partition 200 between the washcoat showerhead 105 and the upper surface 112 of the substrate 110, the partition 200 being positioned within the headset 106 to maintain a first gap between a lower surface 203 of the partition 200 and the upper surface 112 of the substrate 110; - dispensing a washcoat from a washcoat showerhead 105 onto the top surface 204 of the partition 200; - forcing the washcoat through the holes 202 in the partition 200, onto the upper surface 112 of the substrate 110 and into the substrate 110, at least in part by applying suction to the lower surface 113 of the substrate 110.

[0080] Example 1 and 2, i.e., without the use of headset seals 115 or dividers 200 according to the present disclosure. As can be seen, during coating, washcoat 150 leaks out of gaps 109 at the ends of grooves 114 in the substrate and down the sidewalls 108 of the substrate 110. Such leakage, in this case, can result in wasted washcoat, contamination of the sidewalls 108 of the substrate 110, and can also obscure visual identification markings 151 that may be provided on the sidewalls 108 of the substrate.

[0081] 1 and 2, i.e., without the use of headset seal 115 or divider 200 according to the present disclosure. As can be seen, during coating, excess washcoat 150 that was not sufficiently drawn into the passages by the vacuum accumulates in a portion of groove 114. This can result in wasted washcoat and blockage of some of the passages—leading to increased backpressure in use.

[0082] 16 and 17 show a side view of a cut substrate 110 after coating with a washcoat and a bottom view of the substrate 110 after coating but before cutting, respectively. The washcoat was applied using a substrate coating apparatus 1 of the type shown in FIGS. 1 and 2, i.e., without the use of a headset seal 115 or divider 200 according to the present disclosure. As can be seen in FIG. 16, the resulting washcoat profile is highly undulating, with a first portion 152a of the profile being higher on the substrate 110 than a second portion 152b. In fact, in this example, the washcoat in the second portion 152b of the profile reaches all the way to the lower surface 113 of the substrate 110, resulting in a "pull-through" of the washcoat. This can also be seen in FIG. 17, where the "pull-through" areas are indicated by darker spots. It will be noted that the second portion 152b of the washcoat profile is aligned with the groove 114, i.e., the washcoat has "pulled through" the passage directly below the groove 114. This can result in wasted washcoat and also potential blockage of the passage opening in the lower surface 113 of the substrate 110.

[0083] A comparative example was conducted to compare the examples shown in Figures 14-17, but the washcoat was applied using a substrate coating apparatus 100 of the present disclosure, equipped with a headset seal 115 and a partition 200. After coating the substrate with the washcoat, the substrate was sectioned and analyzed for side and end analysis. Using the substrate coating apparatus 100 of the present disclosure, equipped with a headset seal 115 and a partition 200, a washcoat profile was generated that was significantly more uniform than that shown in Figure 16 and completely prevented washcoat "pull-through" of the type shown in Figure 17. Notably, the use of the substrate coating apparatus 100 of the present disclosure enabled an average coating depth across the profile that met the specified coating depth requirements. Furthermore, there was no washcoat retention within the grooves of the substrate of the type shown in Figure 15, and the channels in the substrate were not blocked by the washcoat. Also, unlike the example shown in Figure 14, there was no or only a negligible amount of washcoat on the sides of the substrate.

[0084] Further aspects and embodiments of the present disclosure are described in the following sections. Item A1. A method for coating a substrate with a washcoat, the method comprising: - engaging the substrate with a headset of the substrate coating apparatus to position the upper surface of the substrate under a washcoat showerhead of the substrate coating apparatus; - disposing a partition between the washcoat showerhead and an upper surface of the substrate, the partition having a plurality of holes and positioned within the headset to maintain a first gap between a lower surface of the partition and the upper surface of the substrate; - dispensing a washcoat from a washcoat showerhead onto the top surface of the partition; - forcing the washcoat through the holes in the partition onto the upper surface of the substrate and into the substrate, at least in part by applying suction to the lower surface of the substrate. Paragraph A2. The method of paragraph A1, wherein the divider is disposed in a fixed relationship within the headset. Item A3. The method according to item A1 or A2, wherein the first gap is 2 to 7 mm, optionally 5 mm. Item A4. The method according to any one of items A1 to A3, wherein the partition is disc-shaped and has a thickness of 5 to 15 mm, optionally 7.5 to 12.5 mm, optionally 10 mm, between the upper surface of the partition and the lower surface of the partition. Paragraph A5. The method of any one of paragraphs A1 to A4, wherein the divider is positioned within the headset to maintain a second gap of 80 to 130 mm between the underside of the washcoat showerhead and the top surface of the divider. Section A6. The method of any one of sections A1-A5, wherein the divider comprises more than 500 holes, optionally more than 1000 holes, optionally more than 1500 holes, optionally more than 2000 holes. Item A7. The method of any one of paragraphs A1-A6, wherein the holes are each 1-3 mm in diameter, optionally 2 mm in diameter. Paragraph A8. The method of any one of paragraphs A1-A7, wherein the open area of ​​the partition, defined as the percentage of the total area of ​​the top surface of the partition that is comprised of holes, is 35-55%, optionally 40-50%, optionally about 45%. Section A9. The method of any one of sections A1-A8, wherein the headset further comprises a headset seal, and the divider is disposed within the headset above the headset seal. Item A10. The method according to any one of Items A1 to A9, wherein the upper surface of the substrate is non-planar. Paragraph A11. The method of any one of paragraphs A1-A10, wherein the top surface of the substrate comprises a feature, such as a groove or notch, that extends to a sidewall of the substrate, thereby defining a gap in the sidewall. Item A12. The method according to any one of items A1 to A11, wherein the substrate is selected from a flow-through substrate (eg, a monolithic flow-through substrate) or a filter substrate (eg, a wall-flow filter substrate). Paragraph A13. The method of any one of paragraphs A1-A12, wherein the washcoat comprises a catalytic coating selected from a three-way catalyst (TWC), a selective catalytic reduction (SCR) catalyst, a diesel oxidation catalyst (DOC), a lean NOx trap catalyst (LNT), an ammonia slip catalyst (ASC), a combined selective catalytic reduction catalyst and ammonia slip catalyst (SCR / ASC), or a passive NOx adsorber (PNA). Item A14. The method of any one of paragraphs A1-A13, wherein the washcoat has a viscosity of 3 to 9000 cP, optionally 3 to 54 cP, optionally 32 to 576 cP, optionally 23 to 422 cP, optionally 250 to 4500 cP, or optionally 500 to 9000 cP. Item A15. The method according to any one of Items A1 to A14, further comprising the step according to any one of Items B1 to B14. Item A16. A substrate coating device, a source of washcoat; a washcoat showerhead for dispensing the washcoat toward an upper surface of the substrate; a conduit fluidly connecting a source of washcoat to the washcoat showerhead for delivering the washcoat to the washcoat showerhead; a head set for engaging the substrate so as to position an upper surface of the substrate under the washcoat showerhead; a vacuum generator for sucking the washcoat discharged from the washcoat showerhead through the substrate; A substrate coating apparatus, wherein the headset comprises a partition having a plurality of holes, the partition being positioned between the washcoat showerhead and the upper surface of the substrate when the substrate is engaged with the headset so as to maintain a first gap between a lower surface of the partition and the upper surface of the substrate. Item A17. The substrate coating apparatus according to item A16, wherein the partition is fixedly positioned within the headset so as to be held stationary relative to the housing of the headset. Item A18. The substrate coating apparatus according to item A16 or A17, wherein the first gap is 2 to 7 mm, optionally 5 mm. Item A19. A substrate coating apparatus according to any one of items A16 to A18, wherein the partition is disc-shaped and has a thickness of 5 to 15 mm, optionally 7.5 to 12.5 mm, and optionally 10 mm between the upper surface of the partition and the lower surface of the partition. Item A20. A substrate coating apparatus according to any one of items A16 to A19, wherein the partition is positioned within the headset to maintain a second gap of 80 to 130 mm between the lower surface of the washcoat showerhead and the upper surface of the partition. Item A21. A substrate coating apparatus according to any one of items A16 to A20, wherein the partition comprises more than 500 holes, optionally more than 1000 holes, optionally more than 1500 holes, optionally more than 2000 holes. Item A22. The substrate coating apparatus according to any one of items A16 to A21, wherein the holes each have a diameter of 1 to 3 mm, optionally a diameter of 2 mm. Item A23. A substrate coating apparatus according to any one of items A16 to A22, wherein the open area of ​​the partition, defined as the percentage of the total area of ​​the top surface of the partition that is constituted by holes, is 35 to 55%, optionally 40 to 50%, optionally about 45%. Item A24. The substrate coating apparatus according to any one of Items A16 to A23, wherein the headset further comprises a headset seal, and the partition is disposed within the headset above the headset seal. Item A25. The substrate coating apparatus according to any one of Items A16 to A24, further comprising the apparatus according to any one of Items B16 to B29. Item A26. A substrate coating system comprising: a substrate coating apparatus according to any one of items A16 to A25; and a substrate, wherein the upper surface of the substrate is non-planar, and optionally the upper surface of the substrate has a shape, such as a groove or notch, that extends to a sidewall of the substrate, thereby defining a gap in the sidewall. Item A27. The substrate coating system according to Item A26, further comprising the features of Item B31 or B32. Paragraph A28. A partition configured for use in a substrate coating apparatus, the partition having a disk-shaped body; the disk-shaped body has a thickness between the upper surface of the body and the lower surface of the body of 5 to 15 mm, optionally 7.5 to 12.5 mm, optionally 10 mm; the partition comprises more than 500 holes, optionally more than 1000 holes, optionally more than 1500 holes, optionally more than 2000 holes; the holes are each 1-3 mm in diameter, optionally 2 mm in diameter; A partition wherein the open area of ​​the partition, defined as the percentage of the total area of ​​the top surface of the partition that is constituted by pores, is between 35 and 55%, optionally between 40 and 50%, optionally about 45%. Item B1. A method for coating a substrate with a washcoat, the method comprising: - engaging the substrate with a headset of the substrate coating apparatus to position the upper surface of the substrate under a washcoat showerhead of the substrate coating apparatus; - dispensing a washcoat from a washcoat showerhead toward an upper surface of a substrate; - sucking the washcoat through the substrate by applying suction to the lower surface of the substrate; The method, wherein the step of engaging the substrate with the headset includes engaging a headset seal of the headset with the substrate, the headset seal comprising a peripheral portion extending around the headset and a cantilever portion extending downwardly from the peripheral portion that engages a sidewall of the substrate. Section B2. The method of section B1, wherein the peripheral portion comprises an annular portion, optionally a circular portion or an elliptical portion, extending around the entire circumference of the headset. Item B3. The method according to item B1 or B2, wherein the upper surface of the substrate is non-flat. Item B4. The method according to any one of Items B1 to B3, wherein the cantilever portion has an arc shape. Clause B5. The method of any one of clauses B1-B4, wherein optionally, the top surface of the substrate includes a feature, e.g., a groove or notch, that extends to a sidewall of the substrate, thereby defining a gap in the sidewall, and the cantilevered portion fills the gap to prevent the washcoat from leaking through the gap and down the sidewall of the substrate. Clause B6. The method of clause B5, wherein the cantilevered portion has an arc length that is 105-300% of the arc length of the sidewall gap, optionally 105-200% of the arc length of the sidewall gap. Paragraph B7. The method of any one of paragraphs B1-B6, wherein the cantilevered portion subtends a central angle of 45-120°, optionally 65-75°, optionally 45-90°. Clause B8. The method of any one of clauses B1-B7, wherein the cantilevered portion extends at an angle of 0-15° relative to a plane perpendicular to the peripheral portion, optionally at an angle of 0-10° relative to a plane perpendicular to the peripheral portion, optionally at an angle of about 3° relative to a plane perpendicular to the peripheral portion. Item B9. The method of any one of items B1 to B8, wherein engaging the substrate with the headset causes the cantilevered portion of the headset seal to flex substantially radially. Section B10. The method according to any one of sections B1 to B9, wherein the lower edge of the cantilevered portion is freely protruding and therefore capable of substantially radial flexing. Paragraph B11. The method of any one of paragraphs B1-B10, wherein the cantilevered portion engages a region of the sidewall of the substrate that has a height that is at least 5 mm greater than the depth of the gap in the sidewall of the substrate. Clause B12. The method of any one of clauses B1-B11, wherein the cantilevered portion extends downwardly at least 20 mm below the lower surface of the peripheral portion, optionally at least 30 mm below the lower surface of the peripheral portion, and optionally at least 40 mm below the face rim of the peripheral portion. Item B13. The method according to any one of items B1 to B12, wherein the substrate is selected from a flow-through substrate (eg, a monolithic flow-through substrate) or a filter substrate (eg, a wall-flow filter substrate). Paragraph B14. The method of any one of paragraphs B1-B13, wherein the washcoat comprises a catalytic coating selected from a three-way catalyst (TWC), a selective catalytic reduction (SCR) catalyst, a diesel oxidation catalyst (DOC), a lean NOx trap catalyst (LNT), an ammonia slip catalyst (ASC), a combined selective catalytic reduction catalyst and ammonia slip catalyst (SCR / ASC), or a passive NOx adsorber (PNA). Item B15. The method according to any one of Items B1 to B14, further comprising the step according to any one of Items A1 to A14. Item B16. A substrate coating device, a source of washcoat; a washcoat showerhead for dispensing the washcoat toward an upper surface of the substrate; a conduit fluidly connecting a source of washcoat to the washcoat showerhead for delivering the washcoat to the washcoat showerhead; a head set for engaging the substrate so as to position an upper surface of the substrate under the washcoat showerhead; a vacuum generator for sucking the washcoat discharged from the washcoat showerhead through the substrate; A substrate coating apparatus, wherein the headset comprises: a headset seal for engaging the substrate, the headset comprising a peripheral portion extending around the headset and a cantilever portion extending downwardly from the peripheral portion and configured to engage a sidewall of the substrate. Section B17. The substrate coating apparatus of section B16, wherein the peripheral portion comprises an annular portion, optionally a circular portion or an elliptical portion, extending around the entire circumference of the headset. Item B18. The substrate coating apparatus of paragraphs B16 or B17, wherein the cantilevered portion engages an area of ​​the sidewall of the substrate that has a height that is at least 5 mm greater than the depth of the gap in the sidewall of the substrate. Clause B19. A substrate coating apparatus according to any one of clauses B16 to B18, wherein the cantilevered portion extends downwardly at least 20 mm below the lower surface of the peripheral portion, optionally at least 30 mm below the lower surface of the peripheral portion, and optionally at least 40 mm below the surface rim of the peripheral portion. Paragraph B20. A substrate coating apparatus according to any one of paragraphs B16 to B19, wherein the cantilevered portion extends at an angle of 0 to 15° relative to a plane perpendicular to the peripheral portion, optionally at an angle of 0 to 10° relative to a plane perpendicular to the peripheral portion, and optionally at an angle of about 3° relative to a plane perpendicular to the peripheral portion. Item B21. A substrate coating apparatus according to any one of items B16 to B20, wherein the headset comprises a rigid headset frame that supports a peripheral portion of the headset seal, and the cantilever portion of the headset seal extends below the lower surface of the rigid headset frame. Item B22. The substrate coating device according to any one of Items B16 to B21, wherein the lower edge of the cantilever portion freely protrudes from the rigid headset frame. Item B23. The substrate coating apparatus according to any one of Items B16 to B22, wherein the cantilever portion has an arc shape. Item B24. The substrate coating apparatus according to any one of items B16 to B23, wherein the cantilever portion has a central angle of 45 to 120°, optionally 65 to 75°, optionally 45 to 90°. Item B25. The substrate coating device according to any one of Items B16 to B24, wherein the cantilever portion has a depth of 2.5 to 5.0 mm in the radial direction. Item B26. The substrate coating device according to any one of Items B16 to B25, wherein the peripheral portion and the cantilever portion are integrally formed. Item B27. The substrate coating apparatus according to any one of Items B15 to B24, wherein the peripheral portion and the cantilever portion are separate. Item B28. The substrate coating device according to any one of Items B16 to B27, wherein the peripheral portion and the cantilever portion are formed of different materials. Item B29. The substrate coating apparatus according to any one of items B16 to B28, wherein the cantilever portion has a Shore hardness of 35A to 45A, optionally 40A. Item B30. The substrate coating apparatus according to any one of Items B16 to B29, further comprising the apparatus according to any one of Items A16 to A24. Item B31. A substrate coating system comprising: the substrate coating apparatus according to any one of items B16 to B30; and a substrate, wherein the upper surface of the substrate is non-flat. Paragraph B32. The substrate coating system of paragraph B31, wherein the upper surface of the substrate comprises a feature, such as a groove or notch, that extends to a sidewall of the substrate, thereby defining a gap in the sidewall. Item B33. A substrate coating system according to Item B31 or B32, further comprising the features according to Item A26 or A27. Section B34. A headset seal for engaging a substrate, the headset seal comprising: a peripheral portion for extending around the headset; and a cantilever portion extending from the peripheral portion and configured to engage a sidewall of the substrate. Item B35. A headset seal according to Item B34, wherein the cantilever portion is arc-shaped. Item B36. A headset seal according to item B34 or B35, wherein the cantilevered portion subtends a central angle of 45 to 120°, optionally 65 to 75°, optionally 45 to 90°. Item B37. A headset seal according to any one of items B34 to B36, wherein the cantilever portion has a depth of 2.5 to 5.0 mm in the radial direction. Item B38. The headset seal according to any one of Items B34 to B37, wherein the peripheral portion and the cantilever portion are integrally formed. Item B39. The headset seal according to any one of items B34 to B37, wherein the peripheral portion and the cantilever portion are separate. Item B40. The headset seal according to any one of items B34 to B39, wherein the peripheral portion and the cantilever portion are formed of different materials. Item B41. The headset seal of any one of items B34 to B40, wherein the cantilevered portion has a Shore hardness of 35A to 45A, optionally 40A.

Claims

1. 1. A method of coating a substrate with a washcoat, said method comprising: - engaging the substrate with a headset of a substrate coating apparatus so that an upper surface of the substrate is positioned under a washcoat showerhead of the substrate coating apparatus; - ejecting a washcoat from the washcoat showerhead towards the upper surface of the substrate; - sucking the washcoat through the substrate by applying suction to the lower surface of the substrate; the step of engaging the substrate with the headset includes engaging a headset seal of the headset with the substrate, the headset seal having a peripheral portion extending around the headset and a cantilever portion extending downward from the peripheral portion that engages a sidewall of the substrate.

2. The method of claim 1 , wherein the cantilevered portion is arc-shaped.

3. 3. The method of claim 1 or 2, wherein the top surface of the substrate comprises a shape that extends to the sidewall of the substrate, thereby defining a gap in the sidewall, and the cantilevered portion fills the gap to prevent the washcoat from leaking out of the gap and down the sidewall of the substrate.

4. The method of claim 3 , wherein the shape is a groove or a notch.

5. The method of any one of claims 1 to 4, wherein the cantilevered portion extends at an angle of 0 to 15° relative to a plane perpendicular to the peripheral portion.

6. The method of any one of claims 1 to 5, wherein the cantilevered portion of the headset seal flexes substantially radially when the substrate is engaged with the headset.

7. 1. A substrate coating apparatus comprising: a source of washcoat; a washcoat showerhead for discharging the washcoat toward an upper surface of a substrate; a conduit fluidly connecting the source of washcoat to a washcoat showerhead for delivering washcoat to the washcoat showerhead; a head set for engaging the substrate to position the upper surface of the substrate under the washcoat showerhead; a vacuum generator for sucking the washcoat discharged from the washcoat showerhead through the substrate; 1. A substrate coating apparatus, wherein the headset comprises a headset seal for engaging the substrate, the headset seal comprising a peripheral portion extending around the headset and a cantilever portion extending downwardly from the peripheral portion and configured to engage a sidewall of the substrate.

8. 8. The substrate coating apparatus of claim 7, wherein the headset comprises a rigid headset frame supporting the peripheral portion of the headset seal, the cantilevered portion of the headset seal extending below a lower surface of the rigid headset frame.

9. 9. The substrate coating apparatus of claim 8, wherein a lower edge of said cantilevered portion projects freely from said rigid headset frame.

10. The substrate coating apparatus according to any one of claims 7 to 9, wherein the cantilever portion is arc-shaped.

11. An apparatus for coating a substrate according to any one of claims 7 to 10, wherein the cantilevered portion subtends a central angle of 45 to 120 degrees.

12. 12. The substrate coating apparatus of claim 11, wherein the cantilevered portion subtends a central angle of between 45 and 90 degrees.

13. 12. The substrate coating apparatus of claim 11, wherein the cantilevered portion subtends a central angle of 65 to 75 degrees.

14. A substrate coating system comprising the substrate coating apparatus of any one of claims 7 to 13 and a substrate, wherein the upper surface of the substrate is non-planar.

15. 15. The substrate coating system of claim 14, wherein the top surface of the substrate comprises a shape that extends to the sidewall of the substrate, thereby defining a gap in the sidewall.

16. 16. The substrate coating system of claim 15, wherein the shape is a groove or a notch.

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