WO2024144943A1 - Method and apparatus for web treatment - Google Patents

Abstract

A web treatment apparatus for applying a fluid additive to a web is provided. The web treatment apparatus includes a rotating fluid application roll having an internal pressurized fluid manifold for applying an additive to a web moving across the fluid application roll.

Description

METHOD AND APPARATUS FOR WEB TREATMENT

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Patent Application No. 63/478,135, filed December 31, 2022, which is incorporated herein by reference in its entirety.

BACKGROUND

[0002] Absorbent tissue products, such as paper towels, facial tissues, bath tissues, and the like, are often treated with additives during manufacturing to improve consumer-desired material properties and/or improve attributes enhancing processability. For example, tissue webs are often treated with additive compositions to enhance tissue appearance, strength, softness, or other product attributes. However, existing methods and apparatuses for applying additive compositions are typically large and highly complex.

[0003] Conventional dual rotogravure systems, for example, are capable of applying additive compositions to tissue webs. However, dual rotogravure systems have large footprints, high capital costs, and complex components requiring significant maintenance. Alternative web treatment methods have limited precision. For example, rotary atomization systems and hydraulic spray bars are less complex than dual rotogravure systems but have limited precision and a low turndown ratio. Accordingly, there remains a need for apparatuses and methods for treating tissue webs that are smaller, simpler, and more efficient, while maintaining sufficient precision and throughput capability.

SUMMARY

[0004] Some of the aspects of the present disclosure relate to a web treatment apparatus for applying a fluid additive to a web, the web treatment apparatus including a rotatable fluid application roll having a plurality of openings and configured for supporting the web, a fluid manifold disposed inside the rotatable fluid application roll and adjacent an inner surface of the rotatable fluid application roll. [0005] In some aspects, in addition, or in the alternative, to any preceding aspects, the fluid manifold is configured to output the fluid additive through the openings of the rotatable fluid application roll and onto the web.

[0006] In some aspects, in addition, or in the alternative, to any preceding aspects, the fluid manifold is a pressurized fluid manifold.

[0007] In some aspects, in addition, or in the alternative, to any preceding aspects, the rotatable fluid application roll comprises cylinder defining a hollow open core volume.

[0008] In some aspects, in addition, or in the alternative, to any preceding aspects, the fluid manifold is disposed in the hollow core volume.

[0009] In some aspects, in addition, or in the alternative, to any preceding aspects, the rotatable fluid application roll is a sintered cylinder and the plurality of openings comprise pores defined in sintered cylinder.

[0010] In some aspects, in addition, or in the alternative, to any preceding aspects, the rotatable fluid application roll is a cast cylinder and the plurality of openings comprise holes defined in the cast cylinder.

[0011] In some aspects, in addition, or in the alternative, to any preceding aspects, the rotatable fluid application roll and fluid manifold define a fluid application zone where the fluid additive exits the rotatable fluid application roll.

[0012] In some aspects, in addition, or in the alternative, to any preceding aspects, the web treatment apparatus further includes a pump configured to pump the fluid additive through the fluid manifold and maintain positive fluid pressure in the fluid application zone.

[0013] In some aspects, in addition, or in the alternative, to any preceding aspects, the fluid manifold includes a plurality of ports for transferring fluid from the fluid manifold through the rotatable fluid application roll.

[0014] In some aspects, in addition, or in the alternative, to any preceding aspects, the web treatment apparatus further includes a vacuum device configured to apply negative pressure to the rotatable fluid application roll’s hollow core volume.

[0015] In some aspects, in addition, or in the alternative, to any preceding aspects, the rotatable fluid application roll rotates about a central longitudinal axis. [0016] In some aspects, in addition, or in the alternative, to any preceding aspects, the web treatment apparatus further includes a drive shaft coupled to an end of the rotatable fluid application roll and configured for rotating the rotatable fluid application roll about the central longitudinal axis.

[0017] In some aspects, in addition, or in the alternative, to any preceding aspects, the fluid additive comprises a softening agent.

[0018] In some aspects, in addition, or in the alternative, to any preceding aspects, the web treatment apparatus further includes a housing and wherein the rotatable fluid application roll is disposed within the housing.

[0019] In some aspects, in addition, or in the alternative, to any preceding aspects, the housing includes an inlet opening and an outlet opening such that the web moves into the housing via the inlet and out of the housing via the outlet.

[0020] Additional aspects of the disclosure will be set forth, in pail, in the detailed description, figures, and claims which follow, and in part will be derived from the detailed description or can be learned by practice of the disclosure. It is to be understood that both the foregoing general description and the following detailed description arc exemplary and explanatory only and are not restrictive of the disclosure as disclosed.

BRIEF DESCRIPTION OF DRAWINGS

[0021] Various objects, aspects, features, and advantages of the disclosure will become more apparent and better understood by referring to the detailed description taken in conjunction with the accompanying drawings, in which like reference characters identify corresponding elements throughout. In the drawings, like reference numbers generally indicate identical, functionally similar, and/or structurally similar elements.

[0022] FIG. 1 is a schematic of a web treatment device according to one implementation.

[0023] FIG. 2 is a cross-sectional schematic of the web treatment device of FIG. 1.

[0024] FIG. 3 is a longitudinal cross-sectional view of the web treatment device of

FIG. 1.

[0025] FIG. 4 is a cross-sectional schematic of a web treatment device according to another implementation. [0026] FIG. 5 is a schematic of a web treatment device having a mesh surface according to another implementation.

DETAILED DESCRIPTION

[0027] Reference now will be made in detail to various implementations of the disclosure, one or more examples of which are set forth below. Each example is provided by way of explanation and not limitation. In view of the disclosure, it will be apparent to those skilled in the art that various modifications and variations may be made to the various implementations described herein without departing from the scope or spirit of the disclosure.

[0028] As used herein, forms of the words “comprise,” “have,” and “include” are legally equivalent and open-ended. Therefore, additional non-recited elements, functions, steps or limitations may be present in addition to the recited elements, functions, steps, or limitations.

[0029] As used herein, the terms “web” or “sheet-material” means a flexible substrate, which is useful for household chores, cleaning, personal care, health care, food wrapping, and cosmetic application or removal. Non-limiting examples of web materials for use with the apparatuses and methods disclosed herein include nonwoven substrates, woven substrates, hydro-entangled substrates, air-entangled substrates, paper substrates comprising cellulose (such as tissue paper, toilet paper, or paper towels), waxed paper substrates, coform substrates comprising cellulose fibers and polymer fibers, wet substrates such as wet wipes, moist cleaning wipes, moist toilet paper wipes, baby wipes, film, or plastic substrates (such as those used to wrap food), shop towels, and metal substrates such as aluminum foil. Furthermore, laminated or plied together substrates of two or more layers of any of the preceding substrates are also suitable.

[0030] It is to be understood by one of ordinary skill in the art that the present discussion is a description of example implementations only and is not intended as limiting the broader aspects of the present disclosure, which broader aspects are embodied in the exemplary construction. [0031] Various implementations disclosed herein are directed to a web treatment apparatus for applying treatment fluids (e.g., fluid additive(s)) to a web. The applied additive(s) may be selected for the purpose of improving consumer-desired material properties of the web and/or to improve attributes enhancing web processability. As examples, various additive formulations may be applied to enhance appearance, strength, softness, or other web attributes. The fluid additives may comprise softening agents, medicated fluids, scents, and the like.

[0032] Generally, the web treatment apparatus includes a rotating fluid application roll having an internal pressurized fluid manifold for applying an additive to a web moving across the fluid application roll. In certain implementations, the internal pressurized fluid manifold is held in a stationary position within the fluid application roll. Additionally, the fluid application roll includes openings (e.g., pores) that permit fluid additive to flow out of the internal pressurized fluid manifold and through the fluid application roll. The internal pressurized fluid manifold is oriented such that fluid additive exiting the manifold travels through the fluid application roll at a location where the moving web contacts the fluid application roll, thereby merging the fluid additive with the web.

Web Treatment Apparatus

[0033] FIG. 1 shows a web treatment apparatus 100 for applying a fluid additive to a web 110 (e.g., a tissue web suitable being converted into commercial tissue products). As shown in FIG. 1, the web treatment apparatus 100 generally includes a fluid application roll 120 and an internal pressurized fluid manifold 150.

[0034] In the illustrated implementation, the fluid application roll 120 is an elongated, hollow cylinder defining an inner surface 122 and an outer surface 124, which extend between a first end 126 and a second end 128. The interior of the fluid application roll 120 defines an inner core volume 140 (e.g., the inner volume substantially bounded by the inner surface 122). The fluid application roll 120 also defines a longitudinal axis 125, which extends longitudinally through the center of the of the fluid application roll 120 and about which the fluid application roll 120 rotates (as described in greater detail herein).

[0035] In various implementations, the fluid application roll 120 is constructed from a material of sufficient strength that it is capable of functioning without internal bracing. For example, in one embodiment, the fluid application roll 120 is formed from stainless steel. Additionally, various implementations of the fluid application roll 120 define a plurality of openings 130 extending through the thickness of the fluid application roll 120 (e.g., from the inner surface 122 to the outer surface 124). The openings 130 permit fluid (e.g., fluid additive) to flow through thickness of the fluid application roll 120.

[0036] In certain implementations, the openings 130 are pores extending through thickness of the fluid application roll 120. In such implementations, the fluid application roll 120 may be, for example, sintered using techniques that define a porous roll body.

[0037] In certain implementations, the openings 130 are holes extending through the thickness of the fluid application roll 120. In such implementations, the fluid application roll 120 may be formed, for example, from a metal material that is then drilled to define the plurality of openings 130.

[0038] In certain implementations, the openings are 130 are apertures extending through an open material network. In such implementations, the fluid application roll 120 may be formed, for example, from a rigid skeleton covered with a mesh material (e.g., a metal mesh where apertures defined by the mesh comprise the openings 130). For example, FIG. 5 depicts a web treatment apparatus 500 in which the outer surface 124 of the fluid application roll 120 is defined by a mesh material having a plurality of openings 130.

[0039] As shown in FIG. 1, the pressurized fluid manifold 150 is disposed within the core volume 140 of the fluid application roll 120 and adjacent to the fluid application roll’s inner surface 122. As discussed in greater detail herein, the web treatment apparatus 100 is configured such that the pressurized fluid manifold 150 is held in a fixed position while the fluid application roll 120 is configured to rotate about its longitudinal axis 125. In other words, during operation of the web treatment apparatus 100, the fluid application roll 120 rotates around the stationary internal pressurized fluid manifold 150.

[0040] In the illustrated implementation of FIG. 1, the pressurized fluid manifold 150 extends longitudinally within the fluid application roll’s core volume 140 from the first roll end 126 to the second roll end 128. Generally, the pressurized fluid manifold 150 is configured to receive fluid (e.g., fluid additive) under pressure and direct the fluid out of the pressurized fluid manifold 150 and through the fluid application roll 120. [0041] FIG. 2 shows a cross-sectional view of the web treatment apparatus 100. As shown in FIG. 2, the pressurized fluid manifold 150 includes ports 152 defined through a surface of the pressurized fluid manifold 150 that is adjacent the inner surface 122 of the fluid application roll 120 (i.e., the radially outward surface of the pressurized fluid manifold 150). As indicated by the directional arrows in FIG. 2 (exiting the pressurized fluid manifold 150), the ports 152 allow pressurized fluid to exit the pressurized fluid manifold 150 and travel through the openings 130 of the fluid application roll 120 (e.g., as the fluid application roll 120 rotates about the longitudinal axis 125 and around the stationary pressurized fluid manifold 150).

[0042] In various embodiments, the fluid application manifold’s ports 152 may comprise a plurality of openings in the surface of the fluid application manifold 150 that is adjacent to the inner surface 122 of the fluid application roll 120. For example, in certain embodiments, the ports 152 are holes punched through the fluid application manifold 150.

[0043] As shown in FIG. 1, the area of the fluid application manifold 150 that is adjacent to the inner surface 122 of the fluid application roll 120 and which includes the ports 152 defines a fluid application zone 154. As described in greater detail herein, the fluid application zone 154 comprises the area over which fluid (e.g., fluid additive) exits the pressurized fluid manifold 150, travels through the fluid application roll 120, and is applied to the web 110 moving over the fluid application roll 120.

[0044] FIG. 3 depicts a longitudinal cross-sectional view of the web treatment apparatus 100 (the web 110 is not depicted in FIG. 3). As shown in FIG. 3, the pressurized fluid manifold 150 extends through the fluid application roll’s core volume 140. In the illustrated implementation, the fluid application roll 120 is supported at its first end 126 by roller supports 184. In various implementations, the roller supports 184 (e.g., bearings) support the fluid application roll 120 in a substantially horizontal position (e.g., such that the fluid application roll’s longitudinal axis 125 is horizontal) and permit the fluid application roll 120 to rotate about its longitudinal axis 125. The fluid application roll’s second end 128 is mated to a drive shaft 180 (e.g., powered by a motor) via a drive shaft coupler 182. As indicated in FIG. 3, the drive shaft 180 is configured to rotate the fluid application roll 120 about the longitudinal axis 125 (e.g., in a rotational direction “w” shown in FIG. 3). In this way, the fluid application roll 120 is configured to rotate around the stationary pressurized fluid manifold 150. [0045] As is further depicted in FIGS. 1 and 3, various implementations of the web treatment apparatus 100 further include a fluid source 160 (e.g., containing a treatment fluid or additive fluid configured for application to a web). The fluid source 160 is in fluid communication with the pressurized fluid manifold 150 via a fluid conduit 164, which allows fluid to travel from the fluid source 160 to the pressurized fluid manifold 150. A fluid pump 166 is disposed on the fluid conduit 164 between the fluid source 160 and the pressurized fluid manifold 150. The fluid pump 166 is configured to move fluid under pressure from the fluid source 160 along the fluid conduit 164 and into the pressurized fluid manifold 150, thereby maintaining fluid within the fluid manifold 150 under pressure. In this way, fluid can be driven under pressure through the pressurized fluid manifold 150, through the fluid application roll 120, and onto a moving web 110.

[0046] In some implementations, the fluid application roll’s core volume 140 is maintained under vacuum. For example, as shown in the implementation of FIG. 3, the web treatment apparatus 100 includes a vacuum device 170 in communication with a vacuum manifold 174 via a vacuum conduit 172. As shown in FIG. 3, the vacuum manifold 174 is positioned such that it is in communication with the fluid application roll’s core volume 140. In various implementations, the vacuum device 170 is configured to generate a negative pressure, thereby maintaining the core volume 140 under vacuum. In such implementations, fluid is driven out of the pressurized fluid manifold 150 and through the openings 130 of the fluid application roll 120 when the openings are 130 are in the fluid application zone 154 (e.g., under pressure from the pressurized fluid manifold 150). However, when the openings 130 a e not aligned with the fluid application zone 154 (e.g., as the fluid application roll 120 rotates), negative pressure from the vacuum device 170 can retain fluid in the openings 130 (e.g., preventing fluid from exiting the openings 130 as the fluid application roll 120 rotates).

[0047] In other implementations, the web treatment apparatus 100 does not include a vacuum device 170. In such implementations, the openings 130 of the fluid application roll 120 may be configured to hold the fluid in the roll 120 via capillary pressure over a range of speeds to mitigate slinging (e.g., such that the fluid only discharges under the positive pressure of the pressurized fluid manifold 150). [0048] In other implementations, the web treatment apparatus 100 may be positioned with a housing. For example, FIG. 4 depicts a web treatment device 400 that further includes a housing 470 defining an interior volume 472. As shown in FIG. 4, web treatment apparatus’ fluid application roll 120 (and pressurized fluid manifold 150) are disposed in the housing’s interior volume 472. As can be appreciated from FIG. 4, the housing 470 may be configured to contain the web treatment device 400 such that any overspray of treatment fluid may is contained within the housing 470 (and prevented from reaching other operational components).

[0049] As is further depicted in FIG. 4, the housing 470 also defines an inlet opening 474 and an outlet opening 476 through which the web 110 can move as it passes over the fluid application roll 120. In particular, as the web 110 enters the housing 470 through the inlet opening 474, it passes through sealing member 478. The sealing member 478 is configured to prevent excess treatment fluid from exiting the housing 470 during operation of the web treatment apparatus 400. After the web 110 is treated with treatment fluid (via the fluid application roll 120), the web 110 exits the housing 470 at the outlet 476. The outlet 476 includes an outlet sealing member 480 which is substantially similar to the sealing member 476. In various implementations the sealing members 478, 480 may be rubber seals (e.g., configured with a spring to ensure adequate pressure between opposing sides of the sealing member). In some implementations, the sealing members may include a lubricant (e.g., a silicon emulsion lubricant).

Method of Using Web Treatment Apparatus

[0050] A method of use and operation of the web treatment apparatus 100 will now be described according to various implementations. As shown in FIGS. 1 and 2, the web 110 is directed over outer surface 124 of the fluid application roll 120 such that, as the fluid application roll 120 rotates about its longitudinal axis 125, the web 110 moves generally in the direction of the fluid application roll’s rotation.

[0051] As the web 110 moves across the fluid application roll 120, fluid additive is pumped from the fluid source 160 to the pressurized fluid manifold 150 (e.g., such that the pressurized fluid manifold 150 is full of fluid additive maintained under pressure). While the web 110 is moving, the fluid pump 166 causes a positive pressure within the pressurized fluid manifold 150 that directs the fluid additive out of the pressurized fluid manifold through the manifold’s ports 152 (depicted in FIGS. 1-3).

[0052] Under positive pressure from the pressurized fluid manifold 150, fluid additive is expelled from the pressurized fluid manifold 150 and travels through the openings 130 in the fluid application roll 120 (e.g., from the inner surface 122 through the fluid application roll 120 and exiting from the outer surface 124). The fluid additive exits the fluid application roll 120 in the fluid application zone 154, evenly distributing fluid additive on the portion of the web 110 in the fluid application zone 154 at any given time. Thus, as the web 110 moves past the fluid application zone 154, a fluid receiving surface 112 of the web 110 is treated with fluid additive (the fluid receiving surface 112 being opposite a second web surface 114).

[0053] As can be appreciated from the description herein, various implementations of the web treatment apparatus 100 provide a compact and efficient process for post-treatment of web surfaces. In particular, the web treatment apparatus 100 is self-cleaning, highly efficient, enables a wide turn down ratio, and enables simplified environmental containment for the treatment process. Compared to conventional rotogravure processes, for example, the web treatment apparatus 100 has a smaller footprint, does not require an intensive filtering process, and has a lower cost of equipment. The web treatment apparatus 100 is also operable without the need for recirculation or liquid filtration. Furthermore, the type of post-treatment additive applied may be easily switched, reducing changeover time. Indeed, the combination of a porous roll with an internal fluid application manifold (e.g., further combined with use of capillary and/or differential pressure) enables a more efficient and targeted application of fluid additive than current methods.

[0054] Furthermore, in implementations of the web treatment apparatus 100 having a vacuum device 170, the vacuum device 170 (via the vacuum manifold 174) maintains the core volume 140 of the fluid application roll 120 under negative pressure. This negative pressure helps prevent the fluid additive from being discharged on components other than the web 110. Additionally, in certain implementations (with or without a vacuum device 170), the openings 130 of the fluid application roll 120 may be configured to hold the fluid in the roll 120 via capillary pressure over a range of speeds to mitigate slinging (e.g., such that the fluid only discharges under the positive pressure of the pressurized fluid manifold 150). In this way, the web treatment apparatus 100 provides clean and efficient application of the fluid additive to the web 110.

[0055] Additionally, various implementations of the web treatment apparatus 100 may be configured for providing zoned or patterned application of the fluid additive to the web 110. This may be accomplished for example by configuring the pressurized fluid manifold 150 and/or the fluid application roll 120 to apply fluid additive to the web 110 in particular zones or regions.

[0056] A number of example implementations are provided herein. However, it is understood that various modifications can be made without departing from the spirit and scope of the disclosure herein. As used in the specification, and in the appended claims, the singular forms “a,” “an,” “the” include plural referents unless the context clearly dictates otherwise. The term “comprising” and variations thereof as used herein is used synonymously with the term “including” and variations thereof and are open, non-limiting terms. Although the terms “comprising” and “including” have been used herein to describe various implementations, the terms “consisting essentially of’ and “consisting of’ can be used in place of “comprising” and “including” to provide for more specific implementations and are also disclosed.

[0057] Disclosed are materials, systems, devices, methods, compositions, and components that can be used for, can be used in conjunction with, can be used in preparation for, or are products of the disclosed methods, systems, and devices. These and other components are disclosed herein, and it is understood that when combinations, subsets, interactions, groups, etc. of these components are disclosed that while specific reference of each various individual and collective combinations and permutations of these components may not be explicitly disclosed, each is specifically contemplated and described herein. For example, if a device is disclosed and discussed each and every combination and permutation of the device are disclosed herein, and the modifications that are possible are specifically contemplated unless specifically indicated to the contrary. Likewise, any subset or combination of these is also specifically contemplated and disclosed. This concept applies to all aspects of this disclosure including, but not limited to, steps in methods using the disclosed systems or devices. Thus, if there are a variety of additional steps that can be performed, it is understood that each of these additional steps can be performed with any specific method steps or combination of method steps of the disclosed methods, and that each such combination or subset of combinations is specifically contemplated and should be considered disclosed.

Claims

1. A web treatment apparatus for applying a fluid additive to a web, the web treatment apparatus comprising: a rotatable fluid application roll having a plurality of openings and configured for supporting the web; and a fluid manifold disposed inside the rotatable fluid application roll and adjacent an inner surface of the rotatable fluid application roll; wherein the fluid manifold is configured to output the fluid additive through the openings of the rotatable fluid application roll and onto the web.

2. The web treatment apparatus of claim 1, wherein the fluid manifold is a pressurized fluid manifold.

3. The web treatment apparatus of claim 1, wherein the rotatable fluid application roll comprises cylinder defining a hollow open core volume.

4. The web treatment apparatus of claim 3, wherein the fluid manifold is disposed in the hollow core volume.

5. The web treatment apparatus of claim 3, wherein the rotatable fluid application roll is a sintered cylinder and the plurality of openings comprise pores defined in the sintered cylinder.

6. The web treatment apparatus of claim 3, wherein the rotatable fluid application roll is a cast cylinder and the plurality of openings comprise holes defined in the cast cylinder.

7. The web treatment apparatus of claim 1, wherein the rotatable fluid application roll and the fluid manifold define a fluid application zone where the fluid additive exits the rotatable fluid application roll.

8. The web treatment apparatus of claim 7, further comprising a pump configured to pump the fluid additive through the fluid manifold and maintain positive fluid pressure in the fluid application zone.

9. The web treatment apparatus of claim 1, wherein the fluid manifold includes a plurality of ports for transferring fluid from the fluid manifold through the rotatable fluid application roll.

10. The web treatment apparatus of claim 3, further comprising a vacuum device configured to apply negative pressure to the hollow core volume of the rotatable fluid application roll.

11. The web treatment apparatus of claim 1, wherein the rotatable fluid application roll rotates about a central longitudinal axis.

12. The web treatment apparatus of claim 1, further comprising a drive shaft coupled to an end of the rotatable fluid application roll and configured for rotating the rotatable fluid application roll about a central longitudinal axis.

13. The web treatment apparatus of claim 1, wherein the fluid additive comprises a softening agent.

14. The web treatment apparatus of claim 1, further comprising a housing and wherein the rotatable fluid application roll is disposed within the housing.

15. The web treatment apparatus of claim 14, wherein the housing includes an inlet opening and an outlet opening such that the web moves into the housing via the inlet and out of the housing via the outlet.