Apparatus and method for coating substrate with washcoat

Abstract

To provide an apparatus and a method for coating a substrate with a washcoat.SOLUTION: A apparatus and a method for coating a substrate with a washcoat comprises: engaging the substrate with a head set of a substrate coating apparatus to thereby locate an upper surface of the substrate below a washcoat shower head of the substrate coating apparatus; discharging a washcoat from the washcoat shower head toward the upper surface of the substrate; drawing the washcoat through the substrate by applying suction force to the lower surface of the substrate to suction the washcoat through the substrate. The step of engaging the substrate with the head set includes engagement of a head set seal 115 of the head set with the substrate. The head set seal 115 comprises a perimetral portion 116 extending around the head set, and a cantilever portion 117 extending downward from the perimetral portion which engages with a side wall of the substrate.SELECTED DRAWING: Figure 10

Description

Technical Field

[0001] The present disclosure relates to an apparatus and method for coating a substrate with a washcoat. Specifically, it relates to the coating of a substrate used for the purification of exhaust gas.

Background Art

[0002] Substrates for the purification of exhaust gas can typically include a monolithic substrate provided with passages for the passage of the exhaust gas stream. The substrate can be provided with a coating which can be a catalyst coating. The coating can be applied to the substrate as a washcoat passing through the passages of the substrate. Various methods for applying the coating to the substrate are known. One such method involves applying the washcoat to a first surface (e.g., the upper surface) of the substrate and exposing the second surface (e.g., the lower surface) on the opposite side of the substrate to at least 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 at both the first and second surfaces of the substrate, and the passages extending through the entire length of the substrate. As a result, exhaust gas entering the passages through the first surface of the substrate passes through the substrate in the same passages until the exhaust gas exits from the second surface of the substrate. Alternatively, the substrate can be configured as a filter substrate where some passages are plugged at the first surface of the substrate and other passages are plugged at the second surface of the substrate. In such a configuration, exhaust gas entering a first passage through the first surface of the substrate flows along that first passage partway along the substrate and then passes through the filtering wall of the substrate into a second passage. The exhaust gas then proceeds along the second passage and exits from the second surface of the substrate. Such an arrangement has come to be known in the art as a wall-flow type 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 combination of a selective catalytic reduction catalyst and an ammonia slip catalyst (SCR / ASC), or a passive NOx adsorber (PNA).

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

[0006] The substrate may be made or composed of a ceramic material or a metallic material. For example, the substrate may be made of or consist of aluminium titanate, cordierite (aluminium titanate, cordierite, SiO2 - Al2O3 - MgO), silicon carbide (SiC), an Fe - Cr - Al alloy, a Ni - Cr - Al alloy, or a 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 substantially circular cross-sectional shape, but other cross-sectional shapes, such as square and rectangular, are possible. The upper surface of the substrate body can be defined as the surface positioned at the top during coating, and similarly, the lower surface of the substrate body can be defined as the surface positioned at the bottom during coating. Generally, the upper and lower surfaces are planar and perpendicular to the longitudinal axis of the substrate body.

[0008] Some special substrates may be provided with non-planar upper and / or lower surfaces. For example, the upper surface may be provided with grooves or notches for receiving other components. For example, a sensor of an emission control system can be positioned in the groove or notch when the substrate is incorporated into the emission control system during use. In another embodiment, the upper surface can be concave or convex domed covering part or all of the surface.

[0009] When coating the substrate, it is typically desirable to achieve a substantially "flat" washcoat profile, i.e., to achieve 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 the coated and uncoated portions of the substrate).

[0010] Applying a wash coat to a substrate having a non-planar upper or lower surface has been found to present certain problems. A wash coat applied to the upper surface can preferentially collect or pool within grooves or notches. This can lead to problems in accurately controlling the distribution of the wash coat when it is drawn into the substrate body, and particularly in achieving a substantially flat wash coat profile. For example, when the wash coat is subsequently drawn through the substrate, the substrate can obtain a wavy, i.e., non-flat, wash coat profile. This can occur, for example, when a larger volume of wash coat covers the grooves or notches and is thus further suctioned into the substrate body within the underlying regions of the grooves or notches. A wavy wash coat profile can have a detrimental effect on the operating efficiency of the substrate. For example, a wavy profile can lead to a portion of the substrate not being coated (reducing the catalytic efficiency of the substrate), or a portion of the substrate being unintentionally coated more than once - multiple doses of wash coat are applied - which can harmfully increase the back pressure of the substrate. In some situations, the wash coat can be completely drawn through the substrate body and emerge from the lower surface. This can lead to waste of the wash coat and potentially blockage of the passage openings on the lower surface of the substrate.

[0011] Alternatively or additionally, problems can exist in properly sealing the substrate body to prevent loss of the wash coat down the sides of the substrate body. This can be a particular problem when grooves or notches extend to the side walls of the substrate body. Soiling of the side walls of the substrate by the wash coat can also lead to visual degradation of the substrate, for example obscuring visual identification marks that can be provided on the side walls of the substrate, such as tracking barcodes.

[0012] Alternatively or additionally, even when the substrate has a planar upper surface, there can be problems in achieving spreading the wash coat further across the upper surface of several substrates. For example, for a given substrate, there can be a viscosity threshold where absorption into the passage of the wash coat is too rapid and it does not spread sufficiently or evenly across the entire upper surface. This can lead to an increase in the amount of wash coat entering directly into the passage directly below the wash coat discharge orifice, and thus can lead to a wash coat profile with undulations. SUMMARY OF THE INVENTION

[0013] In a first aspect, the present disclosure provides a method of coating a substrate with a wash coat, the method comprising: - engaging the substrate with a headset of a substrate coating apparatus to position an upper surface of the substrate below a wash coat shower head of the substrate coating apparatus; - disposing a partition between the wash coat shower head and the upper surface of the substrate, the partition being provided with a plurality of holes and being disposed within the headset so as to maintain a first gap between a lower surface of the partition and the upper surface of the substrate; - discharging a wash coat from the wash coat shower head onto an upper surface of the partition; and - introducing the wash coat through the holes of the partition onto and into the upper surface of the substrate, at least in part by applying a suction force to a 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 wash coat; a wash coat shower head for discharging the wash coat towards an upper surface of a substrate; a conduit for fluidly connecting the source of wash coat to the wash coat shower head for supplying the wash coat to the wash coat shower head; A head set for engaging with a substrate so as to place an upper surface of the substrate below a wash coat shower head, a vacuum generator for sucking the wash coat discharged from the wash coat shower head through the substrate, and The head set includes a partition having a plurality of holes, and the partition is disposed between the wash coat shower head and the upper surface of the substrate when the substrate is engaged with the head set 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 including the substrate coating apparatus and the substrate of the above aspect, wherein the upper surface of the substrate is non-planar and, optionally, the upper surface of the substrate extends up to a side wall of the substrate, thereby defining a gap in the side wall, for example, having a shape such as a groove or a notch.

[0016] In a fourth aspect, the present disclosure provides a partition configured to be used in a substrate coating apparatus, the partition including a disk-shaped body, the disk-shaped body having a thickness of 5 to 15 mm, optionally 7.5 to 12.5 mm, and optionally 10 mm between an upper surface and a lower surface of the disk-shaped body, the partition including more than 500 holes, optionally more than 1000 holes, optionally more than 1500 holes, and optionally more than 2000 holes, each hole having a diameter of 1 to 3 mm, optionally 2 mm, and an aperture ratio of the partition defined as a percentage of a total area of an upper surface of the partition formed by the holes being 35 to 55%, optionally 40 to 50%, and optionally about 45%.

[0017] Advantageously, in any of the above aspects, the use of the partition having a plurality of holes assists in preventing the wash coat from accumulating, for example, in grooves or notches on the upper surface when the upper surface of the substrate is non-planar. This has been found to result in a reduction in the adverse effect on the wash coat profile and a reduction in the pull-through of the wash coat from the lower surface of the substrate.

[0018] In particular, in any of the above aspects, advantageously, the suction force can be applied within a specific limited time during which the wash coat is being discharged onto the upper surface of the partition. For example, this limited time can be 5 seconds, preferably 3 seconds, more preferably 1 second. This can advantageously limit or prevent the wash coat from reaching the upper surface of the substrate before the suction force is applied. In this way, the wash coat in contact with the upper surface of the substrate can be immediately sucked into the substrate body by the applied suction force, so that the accumulation or pooling of the wash coat in any grooves or notches on the upper surface can be prevented or at least substantially reduced.

[0019] In addition, in any of the above aspects, maintaining a first gap between the lower surface of the partition and the upper surface of the substrate advantageously minimizes and / or assists in preventing the wash coat from bridging between the partition and the substrate before or after the 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. · The partition can be arranged in a fixed relationship within the headset. · The first gap can be 2 to 7 mm, optionally 5 mm. Thus, the first gap can be optimized not only to minimize or prevent the wash coat from connecting, but also to control and / or limit further spread of the wash coat. For example, the configuration of the wash coat shower head can be selected to achieve a desired initial distribution on the upper surface of the wash coat partition. Thus, it may be desirable that the first gap does not become too large, otherwise the wash coat may be subject to further unwanted disturbances, such as mixing of separate streams, splashing, bouncing, etc. Thus, a first gap of 2 to 7 mm has been found to be most effective. · The partition can be disc-shaped and can have 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. It has been found advantageous to limit the thickness of the partition to 5 to 15 mm in order to minimize additional backpressure in the substrate coating system. · The partition can be arranged within the headset to maintain a second gap of 80 to 130 mm between the lower surface of the wash coat shower head and the upper surface of the partition. A distance of 80 to 130 mm has been found to optimize the distribution of the wash coat on the upper surface of the partition when deposited by the wash coat shower head. · The partition can comprise more than 500 holes, optionally more than 1000 holes, optionally more than 1500 holes, optionally more than 2000 holes. Each hole can be 1 to 3 mm in diameter, optionally 2 mm in diameter. The aperture ratio of the partition, defined as the percentage of the total area of the upper surface of the partition constituted by the holes, can be 35 to 55%, optionally 40 to 50%, optionally about 45%. Thus, advantageously, the partition can be optimized to minimize or prevent the leaching of the wash coat onto the upper surface of the substrate through the partition until suction is applied, while at the same time limiting additional backpressure in the system and providing a good distribution of the wash coat across the entire partition and thus across the entire upper surface of the substrate. · The headset may further include a headset seal, and the partition may be disposed above the headset seal within the headset. · As described above, the upper surface of the substrate may be non-planar. · Additionally, the upper surface of the substrate may extend to the side wall of the substrate, thereby defining a gap in the side wall, for example, having a shape such as a groove or a notch. · The substrate may be selected from a through-flow substrate (e.g., a monolithic through-flow substrate) or a filter substrate (e.g., a wall-flow filter substrate). · The washcoat may include a catalyst coating. The catalyst coating may be 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 combination of a selective catalytic reduction catalyst and an ammonia slip catalyst (SCR / ASC), or a passive NOx adsorber (PNA). · The washcoat may have a viscosity of 3 to 9000 cP.

[0021] In a fifth aspect, the present disclosure provides a method for coating a substrate with a washcoat, the method comprising - engaging the substrate with a headset of a substrate coating apparatus to place an upper surface of the substrate below a washcoat shower head of the substrate coating apparatus; - discharging the washcoat from the washcoat shower head toward the upper surface of the substrate; and - applying a suction force to a lower surface of the substrate to draw the washcoat through 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 includes a peripheral portion extending around the headset and a cantilever portion extending downward from the peripheral portion and engaging the side wall of the substrate.

[0022] In a sixth aspect, the present disclosure provides a substrate coating apparatus, the substrate coating apparatus comprising A source of wash coat, A wash coat shower head for discharging the wash coat toward the upper surface of the substrate, A conduit for fluidly connecting the source of wash coat to the wash coat shower head to supply the wash coat to the wash coat shower head, A head set for engaging the substrate so as to dispose the upper surface of the substrate below the wash coat shower head, A vacuum generator for sucking the wash coat discharged from the wash coat shower head through the substrate, and The head set includes a head set seal for engaging the substrate, the head set seal including a peripheral portion extending around the head set and a cantilever portion extending downward from the peripheral portion and configured to engage the side wall of the substrate.

[0023] In a seventh aspect, the present disclosure provides a head set seal for engaging a substrate, the head set seal including a peripheral portion for extending around the head set and a cantilever portion extending from the peripheral portion and configured to engage the side wall 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 include an annular portion, optionally a circular portion or an elliptical portion, extending around the entire circumference of the head set. · The cantilever portion may be arcuate in shape. · The cantilever portion may have an arc length that is 105% to 300% of the arc length of the gap in the side wall, optionally 105% to 200% of the arc length of the gap in the side wall. · The cantilever portion may be for a central angle of 45° to 120°, optionally 65° to 75°, optionally 45° to 90°. · The cantilever portion can extend at an angle of 0 to 15°, optionally at an angle of 0 to 10°, and optionally at an angle of about 3° with respect to a plane perpendicular to the peripheral portion, with respect to a plane perpendicular to the peripheral portion. · By engaging the substrate with the headset, the cantilever portion of the headset seal can flex substantially radially. · The lower edge of the cantilever portion can project freely, and thus can be capable of flexing substantially radially. · The cantilever portion can engage a region of the sidewall of the substrate that has a height at least 5 mm higher than the depth of the gap in the sidewall of the substrate. · The cantilever portion can extend downward 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, optionally at least 40 mm below the face rim of the peripheral portion. · The peripheral portion and the cantilever portion can be integrally formed or can be separate. The peripheral portion and the cantilever portion can be formed of different materials. · At least the cantilever portion can be formed of a flexible material. · The cantilever portion can have a Shore hardness of 35A to 45A, optionally 40A. · The headset can include a rigid headset frame that supports the peripheral portion of the headset seal, and the cantilever portion of the headset seal can extend below the lower surface of the rigid headset frame. · The lower edge of the cantilever portion can project freely from the rigid headset frame. · The upper surface of the substrate can be non-planar. · The upper surface of the substrate can extend to the sidewall of the substrate, thereby defining a gap in the sidewall, for example, in the form of a groove or notch, and the cantilever portion can fill the gap to prevent the wash coat from leaking from the gap and running down the sidewall of the substrate. · The substrate can be selected from a through-flow substrate (e.g., a monolithic through-flow substrate) or a filter substrate (e.g., a wall-flow filter substrate). · The wash coat may be provided with a catalyst coating. The catalyst coating may be 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 combination of a selective catalytic reduction catalyst and an 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, the substrate coating apparatus may be provided with a partition according to the second aspect and a headset seal according to the sixth aspect.

[0026] In this specification, all references to viscosity refer to the viscosity of the fluid when measured using a Brookfield rotational viscometer fitted with a Small Sample Adaptor and a link suspended spindle, with the temperature of the sample controlled at 25°C. Such viscometers are available from Brookfield Engineering Laboratories, Inc., Middleboro, MA, USA.

[0027] All measurements were made at a shear rate of 14 s -1 As is common general knowledge to those skilled in the art, the spindle, rotational speed, and viscometer model were selected depending on the viscosity of the fluid to ensure that the percent viscometer torque had a minimum measured value greater than 10% and a maximum measured value less than 100%. However, if this is not possible, the percent viscometer torque may have a minimum measured value greater than 0% and a maximum measured value less than 100%. For the measurement of viscosity in this specification, the following spindles were used. The viscosity range of 3 to 100 cP was measured using spindle SC4-18 at 10.6 rpm in an LV viscometer. The viscosity range of 100 to 500 cP was measured using spindle SC4-28 at 50 rpm in an LV viscometer. The viscosity range of 500 to 9000 cP was measured using spindle SC4-28 at 50 rpm with an RV viscometer.

Brief Description of the Drawings

[0028] Henceforth, aspects and embodiments of the present disclosure will be described merely by way of example with reference to the accompanying drawings.

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Mode for Carrying Out 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 mixtures of two or more catalysts, and the like.

[0030] As used herein, the term "about" includes the specified value. For example, "about 45%" includes about 45% and also 45% within the meaning thereof.

[0031] One of ordinary skill in the art will recognize that one or more features of one aspect or embodiment of the present disclosure can 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 wash coat.

[0033] The substrate coating apparatus 1 can include a deposition machine 2 having a housing 40 that houses an apparatus for activating a dispensing mechanism. As shown, the dispensing mechanism can include a piston 41 that is axially movable within a bore 42 so as to discharge fluid from an outlet 43 and direct it toward a conduit 35 disposed downstream of the deposition machine 2.

[0034] The substrate coating apparatus 1 may further include a hopper 3 that defines a hopper reservoir 30 having an outlet 31 connected to the outlet 43 of the depositor 2 via a diaphragm valve 32. The hopper 3 can be filled with a wash coat that is formulated and pre-mixed elsewhere. The wash coat may be pumped into the hopper reservoir 30 or may be supplied under gravity through a suitable conduit into the hopper reservoir 30.

[0035] The outlet 43 of the depositor 2 is in fluid connection with a conduit 35, which may then extend to be in fluid communication with a metering valve 4. The wash coat shower head 5 may be connected to the lower surface of the metering valve 4 with the wash coat shower head 5 positioned above the substrate 10.

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

[0037] FIG. 2 shows an enlarged portion of the substrate coating apparatus 1 of FIG. 1 and shows in more detail how the substrate 10 can be positioned relative to the wash coat shower head 5 and the headset 6.

[0038] FIGS. 1 and 2 show a substrate 10 of a 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 substantially circular cross-sectional shape. The substrate body 11 can be positioned to extend between the headset 6 and the pallet insert 8 such that the upper surface 12 of the substrate body 11 is at the top and the lower surface 13 of the substrate body 11 is at the bottom. The upper surface 12 and the lower surface 13 are planar and orthogonal to the longitudinal axis of the substrate body 11.

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

[0040] The wash coat shower head 5 may be disposed above the headset 6, and preferably may be aligned with the headset 6 and the substrate 10, whereby the central longitudinal direction x of the wash coat shower head 5 coincides with the central longitudinal axes of both the headset 6 and the substrate body 11, as shown in FIG. 2.

[0041] The wash coat shower head 5 may include a shower head housing 21 to which a shower head plate 23 can be coupled using bolts 26 on the lower side. The adapter plate 27 can also be coupled to the upper side of the shower head housing 21 using bolts 28.

[0042] The shower head housing 21 may include a centrally disposed opening that defines an inlet 22 to a shower head cavity 24 defined between the shower head housing 21 and the shower head plate 23. The axis of the inlet 22 may coincide with the longitudinal axis x. The adapter plate 27 may also include a centrally disposed opening sized to receive the central portion 20 of the shower head housing 21 and coincide with the longitudinal axis x. The metering valve 4 may be in fluid communication with and retained at the inlet 22 of the shower head housing 21.

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

[0044] In use, the diaphragm valve 32 is opened and the wash coat is suctioned from the hopper reservoir 30 into the bore 42 by the movement of the piston to the right (as seen in FIG. 1). Next, the diaphragm valve 32 is closed and then the injection portion of the wash coat is moved through the conduit 35 by the action of the piston 41 of the depositor 2 moving to the left (as seen in FIG. 1). The wash coat passes through the metering valve 4 and the inlet 22 and enters the shower head cavity 24. Then, the wash coat passes through the nozzle opening 25 and falls to contact the upper surface 12 of the substrate 10. Then, the wash coat flows down through the passage of the substrate 10. The suction of the wash coat through the substrate 10 is driven at least in part by the suction force applied to the lower surface 13 of the substrate 10 by the vacuum cone 7.

[0045] FIG. 3 shows a substrate 110 having a substrate body 111 with an upper surface 112, a lower surface 113, and a side wall 108. The upper edge portion 107 extends around the upper surface 112. The illustrated substrate 110 has a generally cylindrical shape with a single cylindrical side wall 108. However, the substrate 110 can take other forms, such as an elliptical shape, a square having one or more, for example four, side walls, or a rectangular upper surface.

[0046] The upper surface 112 is provided with grooves or notches 114, hereinafter simply referred to as "grooves 114" for simplicity. The grooves 114 can take numerous shapes or forms and can be of various lengths. The grooves 114 can be shaped and sized to fully or partially receive another component, such as a sensor of the discharge control system.

[0047] The grooves 114 result in a non-planar upper surface 112. The grooves 114 can extend across the entire diameter of the upper surface 112. Alternatively, as shown in FIG. 3, the grooves 114 can extend across a portion of the diameter of the upper surface 112. The grooves 114 can extend to the side wall 108 at one or both of their ends so as to define one or more gaps 109 in the side wall 108 and one or more breaks in the upper edge portion 107. As shown in FIG. 3, a single gap 109 is provided.

[0048] The groove 114 can have various cross-sectional shapes when cut perpendicular to its length. The groove 114 in FIG. 3 has a semi-circular cross-sectional shape. However, depending on the shape of the component housed by the groove 114, other shapes can be used. The gap 109 can have a shape substantially the same as the shape of the groove 114.

[0049] FIG. 4 shows an aspect of a particular disclosure, and a portion of the substrate coating apparatus 100 according to the disclosure is improved to advantageously coat a substrate having a non-planar upper surface and / or lower surface as compared to the coating apparatus 1. The substrate coating apparatus 100 is described as merely an example for coating the substrate 110 in FIG. 3. However, this is not limiting, and it will be understood that the substrate coating apparatus 100 can 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 in FIGS. 1 and 2 are referred to by like reference numerals, such as 1 and 101, 10 and 110, and will not be described in further detail. The reference is made with respect to the above description.

[0051] However, the headset seal 115 of the substrate coating apparatus 101 is different from the headset seal 15 of the substrate coating apparatus 1 shown in FIG. 2.

[0052] In particular, as shown in FIGS. 5 to 8, the headset seal 115 includes a peripheral portion 116 for extending around the headset 106 and a cantilever portion 117 extending from the peripheral portion 116 and configured to engage the side wall 108 of the substrate 110.

[0053] As shown in FIGS. 6 and 7, the peripheral portion may preferably be circular or elliptical in shape and includes an annular portion that extends around the entire circumference of the headset 106 when mounted therein. The peripheral portion 116 may define a central opening 120 surrounded by an inner edge portion 121. The inner edge portion 121 may be perpendicular to the surface of the peripheral portion 116. Alternatively, the inner edge portion 121 may be provided with a shoulder, chamfer, or taper as desired.

[0054] The cantilever portion 117 may be disposed on or adjacent to the inner edge portion 121 of the peripheral portion 116. The cantilever portion 117 may be arcuate in shape. This may be particularly beneficial when the side wall 108 of the base material 110 is cylindrical. The cantilever portion 117 may be for a central angle of 45 to 120°, optionally 65 to 75°, optionally 45 to 90°. The cantilever 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 side wall 108, optionally 105 to 200% of the arc length of the gap 109 in the side wall 108.

[0055] The cantilever portion 117 may extend downward at least 20 mm below the lower surface of the peripheral portion 116, optionally at least 30 mm below the lower surface of the peripheral portion 116, optionally at least 40 mm below the surface rim of the peripheral portion 116.

[0056] As seen in FIGS. 6 and 8, the cantilever portion 117 may have a depth of 2.5 to 5.0 mm in the radial direction.

[0057] As most clearly shown in FIG. 8, the cantilever portion 117 may extend at an angle of 0 to 15° with respect to a plane perpendicular to the peripheral portion 116, optionally at an angle of 0 to 10° with respect to a plane perpendicular to the peripheral portion 116, optionally at an angle of about 3° with respect to a plane perpendicular to the peripheral portion 116.

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

[0059] The peripheral portion 116 and the cantilever portion 117 can be formed of different materials, for example, materials co-molded differently. However, it may preferably be formed from a single material.

[0060] At least the cantilever portion 117 can be formed of a flexible material. The peripheral portion 116 and / or the cantilever portion 117 can be formed from a material having a Shore hardness of 35A to 45A, optionally 40A. The peripheral portion 116 and / or the cantilever portion 117 can be formed from rubber, an 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, the headset seal 115 is mounted within the headset 106. The peripheral portion 116 can extend around the entire circumference of the outer periphery of the headset 106. The cantilever portion 117 is shown extending downward from the peripheral portion 116. The lower edge 123 of the cantilever portion 117 can project freely from the frame with the headset, and thus can be substantially radially flexible as most clearly shown in the photograph of FIG. 9 (FIG. 9 also shows features of the partition 200 described further below).

[0062] By engaging the base member 110 with the headset 106, - the base member 110 can be engaged with the headset 106 and lifted - the cantilever portion 117 of the headset seal 115 can be substantially radially flexed to accommodate the passage of the base member 110. Both the flexibility of the cantilever portion 117 and the limited arc length of the cantilever portion 117 can assist in a more facile and reliable engagement between the base member 110 and the headset 106 while lifting the base member. Thus, some tolerance to lateral misalignment between the base member 110 and the headset 106 can be tolerated and adjusted by flexing the cantilever portion 117.

[0063] Additionally or alternatively, angling the cantilever portion 117 at an angle of 0 to 15° with respect to a plane perpendicular to the peripheral portion 116 can also assist in a more facile and reliable engagement between the substrate 110 and the headset 106 while the substrate is being lifted. Thus, some tolerance to lateral misalignment between the substrate 110 and the headset 106 can be allowed and adjusted by angling the cantilever portion 117.

[0064] In FIG. 4, the groove 114 is shown engaging with the substrate 110 within the headset 106. The peripheral portion 116 can engage sealingly with the upper edge 107 of the substrate 110. This engagement can be with the inner edge 121 of the peripheral portion 116.

[0065] The cantilever portion 117 can engage with the region of the sidewall 108 of the substrate 110. As shown in FIG. 4, preferably, the cantilever portion 117 fills the gap 109 to prevent the wash coat from leaking out of the gap 109 and running down the sidewall 108 of the substrate. The cantilever portion 117 can have a height that is at least 5 mm higher than the depth of the gap 109 in the sidewall 108 of the substrate 110.

[0066] As described above, the cantilever portion 117 can have an arc length that is 105 to 300%, optionally 105 to 200% of the arc length of the gap 109 in the sidewall 108. In this way, i.e., the cantilever portion 117 still fills the gap 109 and is of sufficient length to seal completely, some tolerance to angular misalignment of the substrate 110 can be achieved.

[0067] During operation of the substrate coating apparatus 101, a suction force is applied to the lower surface of the substrate 110 using a vacuum cone. Advantageously, the flexibility and / or relative thinness of the cantilever portion 117 enables the cantilever portion to be “sucked” to engage more firmly with the sidewall 108 by the suction force. This enhances the reliability of the seal between the cantilever portion 117 and the substrate 110.

[0068] During the operation of the device shown in FIG. 4, similar to the substrate coating device 1, the wash coat passes through the metering valve 104 and the inlet 122 and enters the shower head cavity 124. Then, the wash coat passes through the nozzle opening 125, falls, and contacts the upper surface 112 of the substrate 110. Then, the wash coat flows down through the passage of the substrate 110. The suction of the wash coat through the substrate 110 is driven at least in part by the suction force applied to the lower surface 113 of the substrate 110 by the vacuum cone 7. During this process, some wash coat accumulates and can collect in the groove 114. The wash coat can flow along the groove 114. However, the seal provided by the cantilever portion 117 above the gap 109 prevents or substantially reduces any leakage of the wash coat from the gap 109 and the descent of the side wall 108.

[0069] FIG. 10 shows an aspect of a particular disclosure, and a substrate coating device is provided with a partition 200 interposed between a wash coat shower head and the upper surface of a substrate. Hereinafter, the partition 200 will be described as part of the substrate coating device 101 shown in FIGS. 4-9 as merely an example. The partition 200 can be used in other substrate coating devices. However, as described above, particularly beneficial effects can be achieved when the partition 200 is used in combination with the headset seal 115 having the cantilever portion 117.

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

[0071] The partition 200 can have a thickness of 5-15 mm, optionally 7.5-12.5 mm, and optionally 10 mm between the upper surface 204 and the lower surface 203 of the partition 200.

[0072] The partition 200 can include more than 500 holes 202, optionally more than 1000 holes 202, optionally more than 1500 holes 202, and optionally more than 2000 holes 202. Each of the holes 202 can have a diameter of 1 to 3 mm, optionally 2 mm. The holes 202 can be arranged in a regular pattern or randomly.

[0073] The aperture ratio of the partition 200, defined as the percentage of the total area of the upper surface 204 of the partition 200 constituted by the holes 202, can be 35 to 55%, optionally 40 to 50%, and optionally about 45%.

[0074] The partition 200 can be disposed between the wash coat shower head 105 and the upper surface 112 of the substrate 110 when the substrate 110 is engaged with the headset 106 so as to maintain a first gap between the lower surface 203 of the partition 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 partition 200 can be disposed within the headset 106 so as to maintain a second gap between the lower surface of the wash coat shower head 105 and the upper surface 204 of the partition. The second gap can be 80 to 130 mm.

[0076] Preferably, the partition 200 is fixedly disposed within the headset 106 so as to be held stationary with respect to the housing of the headset 106.

[0077] The partition 200 can be formed from metal, plastic, or other rigid materials. Non-limiting examples of suitable materials include polyvinyl chloride (PVC), acetal, nylon 66, and Accura25.

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

[0079] In use, a substrate coating apparatus 101 incorporating a partition 200 can be used in a method of coating a substrate 110 by wash coating, the method comprising: - engaging the substrate 110 with a headset 106 and disposing the upper surface 112 of the substrate 110 below a wash coat shower head 105 of the substrate coating apparatus 101; - disposing a partition 200 between the wash coat shower head 105 and the upper surface 112 of the substrate 110, the partition 200 being disposed within the headset 106 so as to maintain a first gap between the lower surface 203 of the partition 200 and the upper surface 112 of the substrate 110; - discharging a wash coat from the wash coat shower head 105 onto the upper surface 204 of the partition 200; - passing the wash coat through the holes 202 of the partition 200 and onto and into the upper surface 112 of the substrate 110, at least in part by applying a suction force to the lower surface 113 of the substrate 110.

[0080] Example FIG. 14 shows a side view of a substrate 110 to which a wash coat has been 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 a partition 200 according to the present disclosure. As can be seen from the figure, during coating, the wash coat 150 leaks from the gap 109 at the end of the groove 114 of the substrate and runs down the side wall 108 of the substrate 110. Such leakage in this case results in waste of the wash coat, contamination of the side wall 108 of the substrate 110, and may also lead to obscuring of visual identification markings 151 that may be provided on the side wall 108 of the substrate.

[0081] FIG. 15 shows a plan view of a substrate 110 to which a wash coat has been applied using a type of substrate coating apparatus 1 that does not involve the use of the headset seal 115 or the partition 200 as shown in FIGS. 1 and 2, i.e., according to the present disclosure. As can be seen from the figure, during coating, an extra wash coat 150 that was not sufficiently sucked into the passage by vacuum has accumulated in a part of the groove 114. This can result in waste of the wash coat and blockage of some of the passages, and - during use, it can result in an increase in back pressure.

[0082] FIGS. 16 and 17 show a side view of a cut substrate 110 after coating with a wash coat and a bottom view of the substrate 110 after coating but before cutting, respectively. The wash coat is applied using a type of substrate coating apparatus 1 that does not involve the use of the headset seal 115 or the partition 200 as shown in FIGS. 1 and 2, i.e., according to the present disclosure. As can be seen from FIG. 16, the generated wash coat profile is very undulating, with a first portion 152a of the profile where the substrate 110 is one step higher than the second portion 152b. In fact, in this embodiment, the wash coat within the second portion 152b of the profile reaches completely up to the lower surface 113 of the substrate 110, resulting in a "pull-through" of the wash coat. This can also be seen in FIG. 17, where the "pull-through" region is indicated by darker spots. One will notice that the second portion 152b of the wash coat profile is aligned with the groove 114, i.e., the wash coat has "pulled through" the passage directly below the groove 114. This can result in waste of the wash coat and further potential blockage of the passage openings in the lower surface 113 of the substrate 110.

[0083] Comparative examples were carried out for the examples of FIGS. 14 to 17, but a wash coat was applied using the substrate coating apparatus 100 of the present disclosure including the headset seal 115 and the partition 200. The substrate was cut after being coated with the wash coat, and the side surface and the end surface were analyzed. A wash coat profile was generated using the substrate coating apparatus 100 of the present disclosure including the headset seal 115 and the partition 200, which was found to be significantly more uniform than that shown in FIG. 16, and the "pull-through" of the wash coat of the type shown in FIG. 17 was completely prevented. In particular, the use of the substrate coating apparatus 100 of the present disclosure made it possible to obtain an average coating depth across the profile that met the predetermined coat depth requirements. Also, there was no retention of the wash coat in the grooves of the substrate of the type shown in FIG. 15, and the channels of the substrate were not blocked by the wash coat. Also, unlike the example shown in FIG. 14, there was no wash coat or only a very small amount of wash coat on the side surface of the substrate.

[0084] Further aspects and embodiments of the present disclosure are described in the following sections. Item A1. A method of coating a substrate with a wash coat, the method comprising - engaging the substrate with a headset of a substrate coating apparatus and placing an upper surface of the substrate below a wash coat shower head of the substrate coating apparatus; - disposing a partition between the wash coat shower head and the upper surface of the substrate, the partition being provided with a plurality of holes and being disposed in the headset so as to maintain a first gap between a lower surface of the partition and the upper surface of the substrate; - discharging a wash coat from the wash coat shower head onto an upper surface of the partition; and - introducing the wash coat through the holes of the partition onto and into the upper surface of the substrate, at least in part by applying a suction force to a lower surface of the substrate. Item A2. The method according to item A1, wherein the partition is arranged in a fixed relationship within the headset. Item A3. The method according to item A1 or A2, wherein the first gap is 2 - 7 mm, optionally 5 mm. Item A4. The method according to any one of items A1 - A3, wherein the partition is disc-shaped and has a thickness of 5 - 15 mm, optionally 7.5 - 12.5 mm, optionally 10 mm between the upper surface and the lower surface of the partition. Item A5. The method according to any one of items A1 - A4, wherein the partition is arranged within the headset so as to maintain a second gap of 80 - 130 mm between the lower surface of the washcoat shower head and the upper surface of the partition. Item A6. The method according to any one of items A1 - A5, wherein the partition has more than 500 holes, optionally more than 1000 holes, optionally more than 1500 holes, optionally more than 2000 holes. Item A7. The method according to any one of items A1 - A6, wherein each hole has a diameter of 1 - 3 mm, optionally 2 mm. Item A8. The method according to any one of items A1 - A7, wherein the aperture ratio of the partition, defined as the percentage of the total area of the upper surface of the partition formed by the holes, is 35 - 55%, optionally 40 - 50%, optionally approximately 45%. Item A9. The method according to any one of items A1 - A8, wherein the headset further comprises a headset seal and the partition is arranged within the headset above the headset seal. Item A10. The method according to any one of items A1 - A9, wherein the upper surface of the substrate is non-planar. Item A11. The method according to any one of items A1 - A10, wherein the upper surface of the substrate extends to the side wall of the substrate, thereby defining a gap in the side wall, for example, in the form of a groove or notch. Item A12. The method according to any one of items A1 - A11, wherein the substrate is selected from a flow-through substrate (e.g., a monolithic flow-through substrate) or a filter substrate (e.g., a wall-flow filter substrate). Item A13. The method according to any one of Items A1 to A12, wherein the wash coat comprises a catalyst 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 combination of a selective catalytic reduction catalyst and an ammonia slip catalyst (SCR / ASC), or a passive NOx adsorber (PNA). Item A14. The method according to any one of Items A1 to A13, wherein the wash coat 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, 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 apparatus, comprising a source of wash coat, a wash coat shower head for discharging the wash coat toward the upper surface of the substrate, a conduit for fluidly connecting the source of wash coat to the wash coat shower head to supply the wash coat to the wash coat shower head, a headset for engaging the substrate so as to dispose the upper surface of the substrate below the wash coat shower head, a vacuum generator for sucking the wash coat discharged from the wash coat shower head through the substrate, and the headset comprises a partition having a plurality of holes, and the partition is disposed between the wash coat shower head and the upper surface of the substrate when the substrate is engaged with the headset so as to maintain a first gap between the 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 disposed in the headset so as to be held stationary with respect 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. The substrate coating apparatus according to any one of items A16 to A18, wherein the partition is in the shape of a disc and has a thickness of 5 to 15 mm, optionally 7.5 to 12.5 mm, optionally 10 mm between the upper surface and the lower surface of the partition. Item A20. The substrate coating apparatus according to any one of items A16 to A19, wherein the partition is arranged in the head set so as to maintain a second gap of 80 to 130 mm between the lower surface of the wash coat shower head and the upper surface of the partition. Item A21. The substrate coating apparatus according to any one of items A16 to A20, wherein the partition has 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 each of the holes has a diameter of 1 to 3 mm, optionally 2 mm. Item A23. The substrate coating apparatus according to any one of items A16 to A22, wherein the aperture ratio of the partition, defined as the percentage of the total area of the upper surface of the partition formed by the 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 head set further comprises a head set seal, and the partition is disposed in the head set above the head set 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 the 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 extends to the side wall of the substrate, thereby defining a gap in the side wall, for example, having a groove or notch. Item A27. The substrate coating system according to item A26, further comprising the features of item B31 or B32. Item A28. A partition configured to be used in a substrate coating apparatus, the partition comprising a disk-shaped body, The disk-shaped body has a thickness of 5 to 15 mm, optionally 7.5 to 12.5 mm, and optionally 10 mm between the upper surface and the lower surface of the body, The partition has more than 500 holes, optionally more than 1000 holes, optionally more than 1500 holes, and optionally more than 2000 holes, Each of the holes has a diameter of 1 to 3 mm, optionally 2 mm, The partition, defined as the percentage of the total area of the upper surface of the partition constituted by the holes, has an aperture ratio of 35 to 55%, optionally 40 to 50%, and optionally about 45%. Item B1. A method for coating a substrate with a wash coat, the method comprising: - Engaging the substrate with a headset of a substrate coating apparatus and placing the upper surface of the substrate below a wash coat shower head of the substrate coating apparatus; - Discharging a wash coat from the wash coat shower head toward the upper surface of the substrate; - Applying a suction force to the lower surface of the substrate to suck the wash coat through 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 comprising a peripheral portion extending around the headset and a cantilever portion extending downward from the peripheral portion and engaging the side wall of the substrate. Item B2. The method according to Item 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-planar. Item B4. The method according to any one of Items B1 to B3, wherein the cantilever portion has an arc shape. Item B5. Optionally, the upper surface of the substrate extends to the side wall of the substrate, thereby defining a gap in the side wall, for example, having a groove or notch, and the cantilever portion fills the gap to prevent the wash coat from leaking from the gap and the side wall of the substrate from sagging, according to any one of Items B1 to B4. Item B6. The method according to Item B5, wherein the cantilever portion has an arc length that is 105% to 300% of the arc length of the gap in the side wall, optionally 105% to 200% of the arc length of the gap in the side wall. Item B7. The method according to any one of Items B1 to B6, wherein the cantilever portion is for a central angle of 45° to 120°, optionally 65° to 75°, optionally 45° to 90°. Item B8. The method according to any one of Items B1 to B7, wherein the cantilever portion extends at an angle of 0° to 15° with respect to a plane perpendicular to the peripheral portion, optionally at an angle of 0° to 10° with respect to a plane perpendicular to the peripheral portion, optionally at an angle of about 3° with respect to a plane perpendicular to the peripheral portion. Item B9. The method according to any one of Items B1 to B8, wherein by engaging the substrate with the headset, the cantilever portion of the headset seal deflects substantially radially. Item B10. The method according to any one of Items B1 to B9, wherein the lower edge of the cantilever portion protrudes freely and thus can deflect substantially radially. Item B11. The method according to any one of Items B1 to B10, wherein the cantilever portion has a height that is at least 5 mm higher than the depth of the gap in the side wall of the substrate and engages the area of the side wall of the substrate. Item B12. The method according to any one of Items B1 to B11, wherein the cantilever portion extends downward by 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, 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 (e.g., a monolithic flow-through substrate) or a filter substrate (e.g., a wall-flow filter substrate). Item B14. The method according to any one of Items B1 to B13, wherein the washcoat comprises a catalyst 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 combination of a selective catalytic reduction catalyst and an 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 apparatus, a source of washcoat, a washcoat shower head for discharging the washcoat toward the upper surface of the substrate, a conduit for fluidly connecting the source of washcoat to the washcoat shower head to supply the washcoat to the washcoat shower head, a headset for engaging the substrate so as to dispose the upper surface of the substrate below the washcoat shower head, and a vacuum generator for sucking the washcoat discharged from the washcoat shower head through the substrate. The substrate coating apparatus, comprising a headset seal for engaging the substrate, the headset seal comprising a peripheral portion extending around the headset and a cantilever portion extending downward from the peripheral portion and configured to engage the side wall of the substrate. Item B18. The substrate coating apparatus according to Item 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 B19. The substrate coating apparatus according to Item B16 or B17, wherein the cantilever portion engages a region of the side wall of the substrate and has a height that is at least 5 mm higher than the depth of the gap in the side wall of the substrate. Item B19. The cantilever portion extends downward 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, optionally at least 40 mm below the face rim of the peripheral portion, and is a substrate coating apparatus according to any one of Items B16 to B18. Item B20. The cantilever portion extends at an angle of 0 to 15° with respect to a plane perpendicular to the peripheral portion, optionally at an angle of 0 to 10° with respect to a plane perpendicular to the peripheral portion, and optionally at an angle of about 3° with respect to a plane perpendicular to the peripheral portion, and is a substrate coating apparatus according to any one of Items B16 to B19. Item B21. The headset includes a rigid headset frame that supports the peripheral portion of the headset seal, and the cantilever portion of the headset seal extends below the lower surface of the rigid headset frame, and is a substrate coating apparatus according to any one of Items B16 to B20. Item B22. The lower edge of the cantilever portion projects freely from the rigid headset frame, and is a substrate coating apparatus according to any one of Items B16 to B21. Item B23. The cantilever portion has an arc shape, and is a substrate coating apparatus according to any one of Items B16 to B22. Item B24. The cantilever portion is for a central angle of 45 to 120°, optionally 65 to 75°, and optionally 45 to 90°, and is a substrate coating apparatus according to any one of Items B16 to B23. Item B25. The cantilever portion has a depth of 2.5 to 5.0 mm in the radial direction, and is a substrate coating apparatus according to any one of Items B16 to B24. Item B26. The peripheral portion and the cantilever portion are integrally formed, and is a substrate coating apparatus according to any one of Items B16 to B25. Item B27. The peripheral portion and the cantilever portion are separate, and is a substrate coating apparatus according to any one of Items B15 to B24. Item B28. The peripheral portion and the cantilever portion are formed of different materials, and is a substrate coating apparatus according to any one of Items B16 to B27. 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-planar. Item B32. The substrate coating system according to Item B31, wherein the upper surface of the substrate extends to the side wall of the substrate, thereby defining a gap in the side wall, for example, a groove or a notch. Item B33. The substrate coating system according to Item B31 or B32, further comprising the features according to Item A26 or A27. Item B34. A headset seal for engaging with a substrate, comprising a peripheral portion extending around the headset and a cantilever portion extending from the peripheral portion and configured to engage with the side wall of the substrate. Item B35. The headset seal according to Item B34, wherein the cantilever portion has an arc shape. Item B36. The headset seal according to Item B34 or B35, wherein the cantilever portion has a central angle of 45 to 120°, optionally 65 to 75°, optionally 45 to 90°. Item B37. The 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 cantilever portion has a Shore hardness of 35A to 45A, optionally 40A, of the headset seal according to any one of Items B34 to B40.

Claims

**Claim 1** A method of coating a substrate with a wash coat, the method comprising: - engaging the substrate with a headset of a substrate coating apparatus and positioning an upper surface of the substrate below a wash coat shower head of the substrate coating apparatus; - discharging a wash coat from the wash coat shower head toward the upper surface of the substrate; - applying a suction force to a lower surface of the substrate to suck the wash coat through the substrate; and 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 downward from the peripheral portion and engaging a sidewall of the substrate. **Claim 2** The method of claim 1, wherein the cantilever portion is arcuate in shape. **Claim 3** The upper surface of the substrate extends to the sidewall of the substrate, thereby defining a gap in the sidewall, such as a groove or notch, and the cantilever portion fills the gap to prevent the wash coat from leaking from the gap and flowing down the sidewall of the substrate. The method according to claim 1 or 2. **Claim 4** The method according to any one of claims 1 to 3, wherein the cantilever portion extends at an angle of 0 to 15°, optionally at an angle of 0 to 10°, and optionally at an angle of about 3° with respect to a plane perpendicular to the peripheral portion. **Claim 5** The method according to any one of claims 1 to 4, wherein when the substrate is engaged with the headset, the cantilever portion of the headset seal flexes substantially radially. **Claim 6** A substrate coating apparatus, comprising: a source of wash coat; a wash coat shower head for discharging the wash coat toward an upper surface of a substrate; a conduit fluidly connecting the source of the wash coat to the wash coat shower head for supplying the wash coat to the wash coat shower head; a headset for engaging the substrate so as to position the upper surface of the substrate below the wash coat shower head; A vacuum generator for sucking the wash coat discharged from the wash coat shower head through the substrate. The head set includes a head set seal for engaging with the substrate. The head set seal includes a peripheral portion extending around the head set, and a cantilever portion extending downward from the peripheral portion and configured to engage with the side wall of the substrate. A substrate coating apparatus. **Claim 7** The head set includes a rigid head set frame for supporting the peripheral portion of the head set seal. The cantilever portion of the head set seal extends below the lower surface of the rigid head set frame. Optionally, the lower edge of the cantilever portion freely protrudes from the rigid head set frame. The substrate coating apparatus according to claim 6. **Claim 8** The substrate coating apparatus according to claim 6 or 7, wherein the cantilever portion has an arc shape. **Claim 9** The substrate coating apparatus according to any one of claims 6 to 8, wherein the cantilever portion has a central angle of 45 to 120°, optionally 45 to 90°, and optionally 65 to 75°. **Claim 10** A substrate coating system comprising the substrate coating apparatus according to any one of claims 6 to 9 and a substrate, wherein the upper surface of the substrate is non-planar. **Claim 11** The substrate coating system according to claim 10, wherein the upper surface of the substrate extends to the side wall of the substrate, thereby defining a gap in the side wall, for example, a groove or a notch. **Claim 12** A head set seal for engaging with a substrate, comprising a peripheral portion for extending around the head set and a cantilever portion extending from the peripheral portion and configured to engage with the side wall of the substrate. **Claim 13** The head set seal according to claim 12, wherein the cantilever portion has an arc shape. **Claim 14** The head set seal according to claim 12 or 13, wherein the cantilever portion has a central angle of 45 to 120°, optionally 45 to 90°, and optionally 65 to 75°.

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