Tissue embossing processes and products

Abstract

The embossing process involves a pre-straining step that deforms and alters the physical properties of the tissue ply prior to embossing. The pre-straining step may be carried out by passing the web through a first nip formed between a first backing roll and an embossing roll having a plurality of first embossing elements arranged in a first embossing pattern disposed thereon. After the web has been pre-strained, and while it is supported by the plurality of first embossing elements, an aqueous composition, such as water, may be applied to the pre-strained web. In certain instances, the aqueous composition may be applied in a selective manner such that only those portions of the web supported by the plurality of first embossing elements are wetted. Thereafter the wetted tissue web is passed through a second nip to impart an embossing pattern thereon.

Description

[0001] TISSUE EMBOSSING PROCESSES AND PRODUCTS

[0002] BACKGROUND

[0003] It is well known in the art to emboss bond multiple plies of lightweight cellulosic material to form tissue products such as bath tissues, facial tissues, paper towels, industrial wipers, foodservice wipers, napkins, medical pads, and other similar products. The embossed tissue products may comprise one, two, three or more plies. Embossing not only plies multiple tissue plies together but may also impart the tissue product with an aesthetically pleasing pattern. Examples of apparatus and methods for embossing multi-ply paper products are disclosed, for example, in U. S. Patent Nos. 6,733,866, 7,871,692 and 8,287,986 and U. S. Publication No. 2012 / 0156447.

[0004] Embossing may also be used to alter or improve certain tissue product properties such as sheet bulk and perceived softness. For example, tissue products manufactured using conventional creped wet press technology can be embossed subsequent to creping to improve bulk and perceived softness. Embossing often increases the surface area of the sheets by introducing a plurality of protuberances and thereby enhances the bulk and handfeel of the product. Examples of apparatus and methods for embossing multi-ply paper products to improve handfeel and bulk are disclosed, for example, in U. S. Publication Nos. 2005 / 0103456, 2018 / 0142422 and 2018 / 0135254.

[0005] To further enhance the bulk and handfeel of the embossed tissue product, embossing and lamination may be carried out by heating one or more of the tissue plies during the embossing and lamination process. For example, U. S. Publication No. 2020 / 0324506 describes an embossing and lamination process that utilizes a wetting unit and a hot paper micro-embossing device. The individual paper plies are wetted and hot micro-embossed and then fed to a traditional embossing and glue lamination device, comprising two pairs of rubber / steel rolls and a glue dispenser. In another example, U. S. Publication No. 2020 / 0384718 discloses an embossing and lamination assembly having a heating means for heating one of the steel embossing rolls to a temperature between about 100° C and 200° C. The heated steel embossing abuts the adhesive delivery assembly on one side and the marrying roll on another such that adhesive is added to the heated, embossed sheet before being plied at the marrying roll.

[0006] While heating the tissue during the embossing process may enhance the bulk and handfeel of the resulting tissue product, the process may require the addition of water to the entirety of the tissue web to be effective. Rewetting the entire tissue web after it has been dried is problematic as it may require an additional drying step before the web is converted into a tissue product. Additionally, rewetting may cause excessive elongation and rupture of the wetted web as it passes through the embossing nip.As such the rewetting step must be carefully controlled adding cost and complexity to the embossing process.

[0007] Thus, there remains a need in the art for an embossing process that can produce tissue products having an aesthetically pleasing embossing pattern while also improved bulk and handfeel of the tissue product. Additionally, there remains a need in the art for an embossing process that is compatible with existing embossing and lamination processes that does not cause excessive elongation of the tissue or otherwise impede the embossing and lamination process.

[0008] SUMMARY

[0009] The present invention provides a novel embossing process and embossed tissue products produced thereby. The novel process comprises pre-straining the tissue web by passing the web through a first nip formed between a first backing roll and an embossing roll having a plurality of first embossing elements arranged in a first embossing pattern disposed thereon. Generally, pre-straining of the web involves subjecting the web to a mechanical deformation prior to a subsequent converting or processing step, such as embossing, so that the web experiences a defined amount of tensile, compressive, or bending strain. The pre-strain may exceed the elastic limit of at least a portion of the fiber network forming the web, thereby inducing partial or full plastic deformation, altering the modulus of the web, or otherwise modifying the web’s mechanical response to further deformation. In certain instances, the web may be considered pre-strained when the imparted deformation produces measurable changes in fiber configuration, web extensibility, stiffness, or localized strain capacity relative to an unstrained reference web.

[0010] After the web has been pre-strained, and while it is supported by the plurality of first embossing elements, an aqueous composition, such as water, is applied to the pre-strained web. In certain instances, the aqueous composition may be applied in a selective manner such that only those portions of the web supported by the plurality of first embossing elements are wetted. Thereafter the wetted tissue web is passed through a second nip formed, such as a nip formed between the embossing roll and a second backing roll, to further strain the wetted tissue web and impart an embossing pattern thereon.

[0011] Accordingly, in certain aspects the invention provides a process for manufacturing an embossed multi-ply tissue product in which a first tissue ply is conveyed into contact with an embossing roll bearing a plurality of male embossing elements. As the ply engages the outer surface of the embossing roll, the embossing elements mechanically deform the ply, thereby producing a pre-strained tissue substrate. An aqueous composition is then applied to the pre-strained ply to increase its moisture content relative toits initial state, producing a wetted ply with enhanced deformability. The wetted, pre-strained ply is subsequently conveyed into an embossing nip formed between the embossing roll and a counter roll, enabling controlled embossing under conditions that improve pattern definition, ply bonding, or other product attributes.

[0012] In other aspects the invention provides an embossing process in which only a portion of the prestrained tissue web is wetted prior to being passed through a second nip and embossed. That is, only the portion of the web that has been pre-strained and in registration with one or more embossing elements is wetted. In such instances the area of the tissue web that is wetted may only a portion of the total tissue web surface area, such from 2% to 30% of the total surface area of the web, such as from about 2% to about 20% of the total surface area of the web, such as from about 5% to about 15% of the total surface area of the web. In this manner only a relatively small percentage of the web is wetted and reduce or element the need for subsequent drying of the web. Further, once the web is wetted, the same wetted portion may be embossed by passing the wetted web through a second nip.

[0013] In certain instances by pre-straining the web and wetting before embossing, the resulting embossed tissue product has improved product physical properties such as improved bulk and handfeel. Further, in certain aspects, because only a selective or relatively small percentage of the web is wetted, the process does not require subsequent drying of the web and allows form more precise control over the amount of aqueous composition that is applied.

[0014] In other aspects, the present invention provides a method for making an embossed multi-ply tissue product in which two or more plies of tissue are bonded to one another to form a multi-ply tissue. For example, the process may comprise providing a first ply of tissue and providing a second ply of tissue. The first ply is pre-strained by passing the first ply through a first nip formed between a first backing roll and an embossing roll having a plurality of first embossing elements arranged in a first embossing pattern disposed thereon. After the first ply has been pre-strained and while it is supported by the plurality of first embossing elements an aqueous composition, such as water, is applied the web as it is supported by the plurality of first embossing elements. The add-on amount of aqueous composition may range from about 1% to about 5%, based upon the bone-dry weight of the first tissue ply. Thereafter the wetted first tissue ply is passed through a second nip formed between the embossing roll and a second backing roll to further strain the wetted first tissue ply and impart an embossing pattern thereon. The embossed first tissue ply may then be combined with a second tissue ply by passing both plies through a third nip, such as a ply bonding nip formed between the embossing roll and a marrying roll.In certain aspects the aqueous composition may be applied to the surface pre-strained tissue ply by rotogravure printing, flexographic printing, spraying, slot coating, blade coating or foam coating. In certain preferred aspects the aqueous composition is added to the tissue ply immediately prior to embossing such that the wetted tissue ply does not have sufficient time to dry before being conveyed through the second nip.

[0015] In still other aspects the present invention provides an apparatus for the manufacture of an embossed and laminated multi-poly tissue product, the apparatus comprising an applicator for applying an aqueous composition to a pre-strained tissue web, an embossing station and, optionally, a lamination station for laminating an embossed tissue ply to a second tissue ply. Preferably the applicator is configured for applying an aqueous composition to a first and / or a second tissue ply prior to conveying the first and / or second ply to the embossing station. Preferably the applicator comprises one or more wetting units configured to wet the first and / or second tissue plies.

[0016] DESCRIPTION OF THE DRAWINGS

[0017] Fig. 1 is a schematic illustration of an embossing apparatus for manufacturing an embossed, single-ply tissue product.

[0018] Fig. 2 is a schematic illustration of an embossing and lamination apparatus for manufacturing an embossed, multi-ply tissue product.

[0019] Fig. 3 is a detailed view of a wetted and strained tissue web.

[0020] Fig. 4 is a schematic illustration of an embossing and lamination apparatus for manufacturing an embossed, multi-ply tissue product.

[0021] Fig. 5 is a schematic illustration of an embossing and lamination apparatus for manufacturing an embossed, multi-ply tissue product.

[0022] DEFINITIONS

[0023] As used herein, the term "aqueous composition” generally refers to a composition that is predominately water, more specifically a composition comprising at least about 97 wt% water and being substantially free from an adhesive. In certain preferred instances the aqueous composition is free from adhesive. In certain instances, the aqueous composition comprises at least about 98 wt% water, such as at least about 99 wt% water, such as at least about 99.5 wt% water.

[0024] As used herein the term “machine direction” or “MD” generally refers to the direction in which a tissue web or product is produced. The term “cross-machine direction” or “CD” refers to the direction perpendicular to the machine direction.As used herein the term "basesheet” refers to a tissue web formed by any one of the papermaking processes described herein that has not been subjected to further processing, such as embossing, calendering, treatment with an aqueous composition, perforating, plying, folding, or rolling into individual rolled products.

[0025] As used herein the term "tissue product” refers to products made from basesheets and includes, bath tissues, facial tissues, paper towels, industrial wipers, foodservice wipers, napkins, medical pads, and other similar products.

[0026] As used herein the term "ply” refers to a discrete tissue web used to form a tissue product. Individual plies may be arranged in juxtaposition to each other. In a preferred embodiment, tissue products prepared according to the present invention comprise two or more plies arranged in facing relation to one another.

[0027] As used herein, the term "layer” refers to a plurality of strata of fibers, chemical treatments, or the like, within a ply. A "layered tissue web” generally refers to a tissue web formed from two or more layers of aqueous papermaking furnish. In certain instances, the aqueous papermaking furnish forming two or more of the layers comprises different fiber types.

[0028] As used herein, the term "decor embossing pattern” generally refers to a visually preservable pattern disposed on at least one of the outer most surfaces of the tissue product which is formed by one or more embossments which are imparted to the tissue product by embossing. As an example, the height of the embossments forming a decor embossing pattern may range from about 0.2 mm to about 1 mm, such as from about 0.4 mm to about 0.8 mm, such as from about 0.4 mm to about 0.7 mm. This corresponds to embossing tips (engraving) on the cylinder having an engraving height ranging from about 0.2 mm to about 2.2 mm, such as from about 0.5 mm to about 2.0 mm, such as from about 1.0 mm to about 2.0 mm.

[0029] As used herein, the term "pattern” refers to any non-random repeating design, figure, or motif. Generally, the fabrics described herein may comprise decorative patterns comprising a plurality of line elements and / or a plurality of recesses. However, it is not necessary that the line elements form recognizable shapes, and a repeating design of the line elements and / or recesses is considered to constitute a decorative pattern.

[0030] As used herein, the term “surface” when used in reference to basesheet, a tissue ply or a tissue product, means that portion of the sheet, ply or product that is exposed to the external environment. In other words, the surface of a sheet, ply or product is that portion of the sheet, ply or product that is not contacted by another sheet, ply or product.As used herein, the term "user contacting surface” as used herein means that portion of the sheet, ply or product that is brought into contact with the user in-use. For example, it may be the surface of a tissue product that contacts the user's skin when a user wipes their skin with the product. In the case of an embossed sheet, ply or product prepared according to the present invention it may be the case that the embossed areas may not form a portion of the user contacting surface as they may have lower surfaces that lie below the upper most product surface which contacts the user in-use.

[0031] As used herein the term “basis weight” generally refers to the conditioned weight per unit area of a tissue and is generally expressed as grams per square meter (gsm) and is measured as described in the Test Methods section below. While the basis weights of tissue products prepared according to the present invention may vary, in certain embodiments the products have a total basis weight of at least about 20 gsm, such as at least about 30 gsm, such as at least about 35 gsm, such as at least about 40 gsm, such as at least about 45 gsm. In certain instances, the basis weight of the product may range from about 20 gsm to about 70 gsm, such as from about 30 gsm to about 65 gsm, such as about 40 gsm to about 60 gsm. In certain instances, the multi-ply embossed tissue products may comprise two, three or four tissue plies where the basis weight of each individual tissue plie is less than about 25 gsm, such as from about 10 gsm to about 25 gsm, such as from about 10 gsm to about 20 gsm.

[0032] As used herein, the term “caliper” refers to the thickness of a tissue product, web, sheet, or ply, typically having units of microns (pm) and is measured as described in the Test Methods section below.

[0033] As used herein, the term “sheet bulk” refers to the quotient of the caliper (pm) divided by the basis weight (gsm) and having units of cubic centimeters per gram (cc / g). Tissue products prepared according to the present invention may, in certain embodiments, have a sheet bulk of about 6.0 cc / g or greater, such as about 8.0 cc / g or greater, such as about 10.0 cc / g or greater, such as from about 6.0 to about 14.0 cc / g.

[0034] As used herein, the term “geometric mean slope” (GM Slope) generally refers to the square root of the product of machine direction slope and cross-machine direction slope. GM Slope generally is expressed in units of kg. Finished tissue products prepared according to the present disclosure generally have a GM slope of about 10 kg or less. In other aspects, the GM slope can be about 5.0 kg to about 10.0 kg or from about 8.0 kg to about 10.0 kg.

[0035] As used herein, the term “geometric mean tensile” (GMT) refers to the square root of the product of the machine direction tensile strength and the cross-machine direction tensile strength of the web. The GMT of tissue products prepared according to the present invention may vary, however, in certain instances the GMT may be about 800 g / 3" or greater, such as about 900 g / 3” or greater, such as about 1,000 g / 3” or greater, such as about 1,100 g / 3” or greater, such as about 1,200 g / 3” or greater, such asabout 1,300 g / 3” or greater, such as about 1,400 g / 3” or greater, such as about 1,600 g / 3” or greater such as from about 800 to about 1,700 g / 3”.

[0036] As used herein, the term " Stiffness Index" refers to the quotient of the geometric mean tensile slope, defined as the square root of the product of the MD and CD slopes (having units of kg), divided by the average geometric mean tensile strength (having units of grams per three inches) multiplied by 1000. While the Stiffness Index may vary, finished tissue products prepared according to the present disclosure generally have a Stiffness Index of about 10 or less, such as from about 7.0 to about 10.0, such as from about 8.0 to about 10.0.

[0037] Ranges can be expressed herein as from “about” one particular value and / or to “about” another particular value. When such a range is expressed, another aspect includes from the one particular value and / or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent "about,” it will be understood that the particular value forms another aspect. It should be further understood that the endpoints of each of the ranges are significant both in relation to the other endpoint and independently of the other endpoint.

[0038] Similarly, when values are expressed as approximations, by use of the antecedent “about,” it will be understood that the particular value forms another aspect. It will be further understood that the endpoints of each of the ranges are significant both in relation to the other endpoint and independently of the other endpoint. Unless stated otherwise, the term “about” means within 5% (e.g., within 2% or 1 %) of the particular value modified by the term “about.”

[0039] Throughout this disclosure, various aspects of the disclosure can be presented in a range format. It should be understood that the description in range format is merely for convenience and brevity and should not be construed as an inflexible limitation on the scope of the disclosure. Accordingly, the description of a range should be considered to have specifically disclosed all the possible subranges as well as individual numerical values within that range. For example, a description of a range such as from 1 to 6 should be considered to have specifically disclosed subranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as individual numbers within that range, for example, 1, 2, 2.7, 3, 4, 5, 5.3, 6 and any whole and partial increments therebetween. This applies regardless of the breadth of the range.

[0040] All percentages and ratios are calculated by weight unless otherwise indicated. All percentages and ratios are calculated based on the total composition unless otherwise indicated.

[0041] Unless otherwise noted, all component or composition levels are in reference to the active portion of that component or composition, and are exclusive of impurities, for example, residual solventsor by-products, which may be present in commercially available sources of such components or compositions.

[0042] DESCRIPTION

[0043] It has now been discovered that embossed tissue products may be prepared in a simple, efficient process that combines pre-straining of the tissue web, wetting of the pre-strained tissue web and embossing into a single unit operation. The resulting embossed tissue products may have one more improved physical properties compared to conventionally embossed tissue products. For example, the clarity of the decor embossing pattern may be improved by pre-straining and wetting the tissue web prior to embossing. In other instances, the bulk and / or handfeel may be improved by pre-straining and wetting the tissue web prior to embossing.

[0044] Accordingly, in one particularly preferred embodiment, the products of the present invention are embossed by an embossing apparatus comprising a means for applying an aqueous composition to a tissue webs while it is supported by a plurality of embossing elements and prior to the web entering an embossing nip, which may be formed between the embossing roll which supports the wetted tissue web and an opposed counter roll. This process is not only efficient means of carrying out straining, wetting and embossing in a single unit but may reduce product stiffness, increase the caliper of the embossed tissue product, even at lower embossing nip loads, while preserving the integrity of the tissue web and reducing tensile degradation In still other instances the process may yield embossed tissue products having improved decor embossing pattern clarity and improved ply attachment.

[0045] Individual tissue plies, also referred to herein as a basesheet or a web, may be any fibrous web suitable for embossing, including paper, tissue, nonwovens, films, laminates, combinations thereof and the like. In the case of tissue basesheet, which for purposes herein means basesheets intended for use as facial tissue, bath tissue, table napkins and paper towels, can be layered or nonlayered, creped or uncreped, wet pressed or through-air dried, single-ply or two-ply or multi-ply, and can comprise natural and / or synthetic fibers.

[0046] The tissue products produced as described may comprise, one, two, three or four tissue plies, where the individual plies may be made by well-known wet-laid papermaking processes such as, for example, creped wet pressed, modified wet pressed, creped through-air dried (CTAD) or uncreped through-air dried (UCTAD). For example, creped tissue webs may be formed using either a wet pressed or a modified wet pressed process such as those disclosed in U. S. Pat. Nos. 3,953,638, 5,324,575 and 6,080,279, the disclosures of which are incorporated herein in a manner consistent with the instant application. In these processes the embryonic tissue web is transferred to a Yankee dryer, whichcompletes the drying process, and then creped from the Yankee surface using a doctor blade or other suitable device.

[0047] In other instances, the tissue basesheet may be manufactured by a through-air dried process known in the art. In such processes the embryonic web is noncompressively dried. For example, textured tissue plies may be formed by either creped or uncreped through-air dried processes. Particularly preferred are uncreped through-air dried webs, such as those described in U. S. Pat. No. 5,779,860, the contents of which are incorporated herein in a manner consistent with the present disclosure.

[0048] In still other instances individual tissue plies may be manufactured by a process including the step of using pressure, vacuum, or air flow through the wet web (or a combination of these) to conform the wet web into a shaped fabric and subsequently drying the shaped sheet using a Yankee dryer, or series of steam heated dryers, or some other means, including but not limited to tissue made using the ATMOS process developed by Voith or the NTT process developed by Metso; or fabric creped tissue, made using a process including the step of transferring the wet web from a carrying surface (belt, fabric, felt, or roll) moving at one speed to a fabric moving at a slower speed (at least 5 percent slower) and subsequently drying the sheet. Those skilled in the art will recognize that these processes are not mutually exclusive, e.g., an uncreped TAD process may include a fabric crepe step in the process.

[0049] The embossing process of the present invention is particularly useful in the processing of individual plies having a basis weight ranging from about 10 gsm to about 35 gsm, such as from about 12 gsm to about 30 gsm.

[0050] The embossed tissue products prepared according to the present invention may have a basis weight of at least about 20 gsm, such as at least about 30 gsm, such as at least about 35 gsm, such as at least about 40 gsm, such as at least about 45 gsm. In certain instances, the product basis weight may range from about 20 gsm to about 70 gsm, such as from about 30 gsm to about 65 gsm, such as about 40 gsm to about 60 gsm In certain instances, the multi-ply embossed tissue products may comprise two, three or four tissue plies where the basis weight of each individual tissue plie is less than about 25 gsm, such as from about 10 gsm to about 25 gsm, such as from about 10 gsm to about 20 gsm.

[0051] The embossed tissue products prepared according to the present invention may have a geometric mean tensile (GMT) of about 800 g / 3” or greater, such as about 900 g / 3” or greater, such as about 1,000 g / 3" or greater, such as about 1,100 g / 3” or greater, such as about 1,200 g / 3” or greater, such as about 1,300 g / 3” or greater, such as about 1,400 g / 3” or greater, such as about 1,600 g / 3” or greater. In certain instances, the GMT may range from about 800 g / 3” to about 1,700 g / 3”, such as from about 900 g / 3” to about 1,600 g / 3”, such as from about 1,000 g / 3” to about 1,500 g / 3”. In certaininstances, the multi-ply embossed tissue products may comprise two, three, or four tissue plies where the GMT of each individual tissue plie is less than about 600 g / 3", such as from about 200 g / 3” to about 425 g / 3”, such as from about 350 g / 3’’ to about 550 g / 3”.

[0052] At the foregoing tensile strengths, the tissue products may have a Stiffness Index of about 10.0 or less, such as from about 7.0 to about 10.0, such as from about 8.0 to about 10.0. For example, the present invention provides multi-ply rolled bath tissue products comprising two or more embossed tissue plies laminated to one another where the product has a GMT from about 1,000 g / 3” to about 1,500 g / 3” and a Stiffness Index from about 8.0 to about 10.0.

[0053] In other instances, the multi-ply embossed tissue products of the present invention may have a sheet bulk greater than about 6.0 cc / g, such as from about 6.0 to about 14.0 cc / g. In certain instances, at the foregoing sheet bulks, the tissue products may have a sheet caliper greater than about 300 m, such as greater than about 400 pm, such as greater than about 500 pm, such as greater than about 600 pm, such as from about 300 to about 1,000 pm.

[0054] In certain preferred embodiments the products of the present invention may comprise multi-ply products where at least one of the plies is embossed and the two or more tissue plies are bonded together along a plurality of bonded areas. In certain instances, the bonded areas may correspond to the embossments disposed on the one or more tissue plies. The embossed area, relative to the total area of the ply surface, and in-turn the bonded area, may range from about 2% to about 50%, such as from about 2% to about 30%, such as form about 2% to about 20%. The amount of surface area occupied by the decor embossing pattern may be by delineating the perimeter of the decor embossing pattern, which may be known by those of skill in the art as the “footprint" subtended by the periphery of embossing pattern.

[0055] In certain instances, it may be desirable to reduce the total embossed area, without sacrificing ply attachment, such that the total embossed surface area ranges from about 2% to about 20%, such as from about 2% to about 10%, such as from about 3% to about 8%, yet having a ply attachment strength of at least about 6 gf, such as from about 6 gf to about 12 gf. Without desiring to be bound by theory, providing a tissue product having an embossed area less than about 20% and still more preferably less than about 10% and a decor embossing pattern comprising open, curvilinear elements, particularly a curvilinear line element formed from a plurality of dot emboss elements communicates to the consumer that the product is soft and cushiony while providing good ply attachment, even without the use of an adhesive.

[0056] The tissue products may be converted into rolled tissue products, such as rolled bath tissue products, comprising a multi-ply embossed tissue web spirally wound about a core. Such rolled tissueproducts may comprise a plurality of connected, but perforated, tissue sheets that may be separated from adjacent sheets by a user.

[0057] The embossed tissue products of the present invention may be converted into finished tissue products for use by user using well known processing machines (converting machines) which include operations such as unwinding the base tissue sheets, calendering, printing, embossing, lamination of individual plies, as well as cutting, perforation and folding.

[0058] Prior to converting, it is generally preferred that the tissue ply, or plies, are embossed by the embossing process described herein. The embossing process is generally carried out in the nip between an embossing roll, also referred to herein as a patterned roll, and an anvil roll, also referred to herein as a counter roll or backing roll. The embossing roll can have protrusions, referred to as embossing elements, on its circumferential surface leading to embossments in the resulting embossed tissue ply.

[0059] The present invention provides an embossing process that it is preceded by a process that strains the tissue ply prior to embossing the ply and imparting an embossing pattern thereon. The straining process generates additional product thickness by straining the ply beyond its elastic yield point, preferably without rupturing or otherwise fracturing the ply. Straining of the ply may be carried out by the same embossing roll used to impart an embossing pattern to the ply. The surface of the embossing roll may have a plurality of specially designed protuberances. When the ply is contacted with the specifically designed protuberances the ply is deformed and strain is impart to the ply thereby altering its properties.

[0060] The exact geometry of the protuberances and the extent to which the emboss rolls are loaded together (engaged with one another at a depth of engagement), change the amount of strain which is imparted to the ply, and therefore the amount of modification to the material properties. Wetting or heating of the ply may also be employed to further strain the ply and impact the properties of the resulting embossed tissue product.

[0061] The magnitude of strain imparted to the tissue ply as it engages the embossing protuberances is influenced by several interrelated geometric factors, including the height, shape, and sidewall angle of the protuberances, the pitch or spacing between adjacent protuberances, and the relative size and distribution of the individual embossing elements. These variables collectively determine the degree of mechanical interference experienced by the ply as it is driven into the embossing pattern. The present method, which introduces a controlled pre-strain into the ply prior to embossing, has been found to significantly modify the material response of the ply and the performance attributes of the resulting tissue product. This effect is especially pronounced when the geometry of the embossing elements, combinedwith the interference between opposing emboss rolls, produces localized strains of sufficient magnitude to induce permanent deformation of the fibers within the ply.

[0062] In some embodiments, the imposed strain exceeds the elastic limit of the fiber network, resulting in localized structural failure. Such localized failure occurs when the strain at a discrete region of the ply surpasses the maximum strain capacity corresponding to the modulus of the ply material. When this threshold is exceeded, the fiber network undergoes irreversible plastic deformation, micro-fracturing, or other permanent structural changes that alter the mechanical properties, bulk, and tactile characteristics of the finished tissue.

[0063] For purposes of design and process control, the strain imparted to the ply— assuming relative slippage occurs between the sheet and the contacting embossing protuberances— may fall within a calculated range of approximately 20% to about 50%, such as from about 20% to about 45%, or from about 20% to about 40%. Strain levels within these ranges have been found sufficient to induce the desired degree of fiber deformation or localized failure while maintaining overall ply integrity during continuous processing.

[0064] The degree of strain may be estimated based upon the shape of the embossing elements and the anticipated deformation of the web as it is brought into contact with the elements, or it may be measured by analyzing an actual image of the deformed sheet. In certain instances, a strain-analysis algorithm (e.g., digital image correlation, edge-tracking, or vector-field deformation software) may be used to quantify mechanical strain. The algorithm compares pre-emboss and in-nip images to calculate displacement fields. Strain components may be calculated by measuring the axial strain (ex) along the machine direction; transverse strain (ey) across the cross-machine direction and shear strain (yxy) in regions undergoing angular distortion, where the local strain at a point is equal to:

[0065] AL

[0066] ε = ΔL / Lo

[0067] where Lois the initial spacing between markers and AL is the measured change in spacing during deformation. Strain values may range from approximately 20% to 50% depending on protuberance geometry, roll interference, and degree of sheet slippage.

[0068] The design of the emboss roll elements / protuberances can take many shapes to accomplish the desired imparted strain intent. Circular or discrete dot protuberances when clustered together in a repeating pattern, generate a repeatable strain profile in the fibrous structure ply when the emboss rolls are run to a proper interference.Line elements (protuberances) can also be used in the present process. Line elements combined with circular or non-line elements can also be used. A pattern of elements may use both line elements and circular elements. This combination of line elements and circular elements yields more variation in localized stress to the fibrous structure ply since the geometry is more variable.

[0069] One process for producing an embossed and laminated tissue product according to the present invention is illustrated in FIG. 1. In the illustrated embodiment, a first tissue ply 100 is conveyed through a first nip 120 formed between a backing roll 110 and patterned embossing roll 112. As the ply 100 passes through the nip 120 it is pre-strained as it conforms to the embossing elements which protrude from the surface of the embossing roll 112. A series of applicator rolls 150, 152 deliver an aqueous solution to the pre-strained ply 101 as it is supported by the embossing roll 112 thereby wetting the prestrained ply 120. The now wet and pre-strained ply 103 continues to be conveyed to a second nip 122 formed between the embossing roll 112 and a second backing roll 114. The wet and pre-strained ply 103 is embossed as it passes through the second nip 122. The embossed tissue ply 103 may then be subject to further converting to yield an embossed single-ply tissue product.

[0070] With reference now to FIG. 2, a process for producing an embossed multi-ply product is illustrated. In the illustrated embodiment, a first tissue ply 100 is conveyed through a first nip 120 formed between a backing roll 110 and patterned embossing roll 112. As the ply 100 passes through the nip 120 it is pre-strained as it conforms to the embossing elements which protrude from the surface of the embossing roll 112. A series of applicator rolls 150, 152 deliver an aqueous solution to the pre-strained ply 101 as it is supported by the embossing roll 112 thereby wetting the pre-strained ply 120. The now wet and pre-strained ply 103 continues to be conveyed to a second nip 122 formed between the embossing roll 112 and a second backing roll 114. The wet and pre-strained ply 103 is embossed as it passes through the second nip 122.

[0071] A second ply 105 is conveyed through a third nip 126 formed between a second patterned roll 114 and backing roll 116 to yield an embossed second ply 107. The embossed second ply 107 continues to be conveyed to a fourth nip 124 formed between the embossing roll 102 and a marrying roll 118. The embossed first ply 103 and the embossed second ply 107 are joined together as they pass through the fourth nip 124 to yield an embossed multiply product, which may be subject to further converting.

[0072] With reference now to FIG. 3, the pre-straining and selective wetting of the web may be seen. Pre-straining of the web 120 occurs as it conforms to the embossing element 150. Once the web is prestained it may be wetted while still supported by, and in contact with, the embossing element 150. In this manner an aqueous solution 160 is only the portion of the portion of the web 120 that is supported by the embossing element 150Turning now to FIG. 4, another process for producing a multi-ply embossed tissue product is illustrated. A first tissue ply 201 is unwound from a first parent roll 200 and conveyed to a first embossing unit. The first embossing unit comprises a first backing roll 211 and a first embossing roll 212, which are urged together to form a first nip 210 through which the first tissue ply 201 passes to pre-strain the first ply 201 as it conforms to the plurality of embossing elements 216. In certain instances, the plurality of embossing elements 216 may extend from the surface 219 of the embossing roll 212 a height, generally measured from a plane normal to the surface of the embossing roll, of less than about 1.00 mm and more preferably less than about 0.80 mm, such as from about 0.50 to about 1.00 mm. In certain preferred embodiments the embossing elements 216 may be arranged to form a decor embossing pattern.

[0073] Once a pre-strained ply 205 emerges from the first nip 210 the pre-strained ply 205 encounters a wetting unit 250, which comprises an aqueous composition 251 disposed in a reservoir and an applicator roll 252. An aqueous composition 251 is transferred to the applicator roll 252 and applied to the distal ends 232 of the pre-strained ply 205 which are formed by virtue of first ply contacting and being strained by the plurality of embossing elements 216.

[0074] The pre-strained and wetted ply continues to be conveyed through a first embossing nip 210 formed between the embossing roll 212 and a marrying roll 240. Generally, a force or pressure is applied to one or both rolls, 211, 240 such that the rolls 211, 240 are urged against one another causing the first pre-strained and wetted ply to conform about the embossing elements 216 causing the web to be imparted with a plurality of embossments.

[0075] In the embodiment illustrated in FIG. 4, the aqueous composition 251 is contained within a bath 250 and is initially applied to the applicator roll 252 via one or more rolls. The applicator roll 252 may comprise any suitable roll or surface capable of transferring an aqueous composition onto the surface of the tissue ply. The applicator roll, for instance, may be substantially smooth, such as a chrome plated steel roll, a ceramic roll, or a rubber-coated roll. In one embodiment, the applicator roll comprises an anilox roll that may be engraved and textured. For instance, the applicator roll may comprise a gravure roll having a surface covered with recessed cells that hold the aqueous composition due to capillary action.

[0076] The manner in which the aqueous composition is applied to the applicator roll can vary depending upon the particular application method. In the embodiment illustrated in FIG. 1, for instance, the aqueous composition 251 is contained in a bath 250 and transferred to the applicator roll 252 via a series of counter rotating rolls. In an alternative embodiment, the process may include a flooded nipbetween an applicator roll and a counter rotating roll. A pool of the aqueous composition is maintained within the flooded nip for application to the applicator roll.

[0077] In other embodiments, the applicator roll may be at least partially enclosed within a chamber. The aqueous composition can be applied to the applicator roll within the chamber by flowing the composition onto the roll, by extruding the composition onto the roll, or by spraying the composition onto the roll. If desired, one or more blades may be placed adjacent to the applicator roll for maintaining the proper amount of aqueous composition on the applicator roll prior to contact with the patterned roll.

[0078] In certain embodiments the applicator may comprise a metering roll comprising a plurality of individual cells, such as a gravure roll, and a transfer roll. The metering roll is in fluid communication with a reservoir, such as a chamber doctor blade reservoir, which is supplied with the aqueous composition. Upon axial rotation, the metering roll acquires the aqueous composition from the reservoir, which may precisely fill in the individual cells of the metering roll. The metering roll then transfers a particular quantity of the aqueous composition to the transfer roll. The transfer roll then transfers the aqueous composition tissue ply.

[0079] Generally, the applicator unit is configured to apply the aqueous composition to only a portion of the tissue ply surface. For example, in certain instances the applicator may be configured such that only the strained portion of the tissue ply is treated. The strained portion generally corresponds to the portion of the web in contact with the one or more embossing elements. Further, the aqueous composition may be applied in a pattern or may be applied randomly.

[0080] The applicator unit may be configured to provide a controlled amount of aqueous composition the tissue ply such that the basis weight of the tissue ply is increased in the range from about 1% to about 5% of the basis weight of the tissue ply, such as from about 2% to about 3%. Preferably the wetted tissue ply is sufficiently wetted such that it does not dry before passing through the embossing nip formed between the embossing roll and backing roll.

[0081] In certain instances, it may be desirable to heat the aqueous composition prior to wetting of the tissue ply. In this manner the temperature of the aqueous composition being applied to the tissue ply may be about 50°C or greater, such as about 55°C or greater, such as about 60°C or greater, such as about 65°C or greater, such as about 70°C or greater. In certain instances, the temperature of the aqueous composition may range from about 50°C to about 80°C, such as from about 60°C to about 75°C, about 65°C to about 70°C. The aqueous composition can be heated using any suitable heating device, such as an infrared heater, an electrical resistance heater, a gas heater or the like.With continued reference to FIG. 1, the aqueous composition 251 is transferred from the surface the applicator roll 252 to the surface of the pre-strained ply 205, particularly the distal ends 232 as they are supported by, and in contact with, the first elements 216. The amount of aqueous composition applied to the patterned roll 252 and subsequently the embossed tissue ply 205 may depend upon various factors, including the roll speeds, the viscosity of the aqueous composition, the application rate, and any particular pattern present on the applicator roll 252.

[0082] To form a two-ply tissue product, a second parent roll 202 is unwound and the second tissue ply 204 passed into a second embossing nip 215 formed between a second backing roll 217 and a second embossing roll 213. The second backing roll 217 generally has a smooth outer surface, which may be deformable. In certain instances, the second backing roll 217 has an outer covering comprising a natural or synthetic rubber and may have a hardness greater than about 40 Shore (A), such as from about 40 to about 100 Shore (A).

[0083] The second embossing roll 213 generally comprises a plurality of protuberances 222 extending from its peripheral surface 221. The protuberances are generally in the form of a second embossing pattern. In certain embodiments the protuberances may be in the form of a micro-embossing pattern, which may be comprised of truncated-pyramid shaped protuberances or the like. A pattern of this type may have a density of at least 10 protuberances / cm2, such as at least 15 protuberances / cm2, such as from about 30 to about 90 protuberances / cm2.

[0084] As the second ply 204 passes through the second embossing nip 215 it is imparted with a plurality of emboss elements 231, which may be arranged to form a pattern. The embossed second ply 224 is then conveyed and brought into facing relation with the embossed first ply 205 using a marrying roll 240, as will be described in more detail below. While in certain instances the second engraved embossing roll 213 and impression roll 217 may be arranged relatively close to the first pair of rolls 211, 212 and the marrying roll 240, this is not necessary as the present method does not relying upon registration of the first and second embossing patterns with one another. In this manner, the present method differs from so called nested method embossing, such as that described in U. S. Publ. No.

[0085] 20120156447, where the embossing elements of the first embossing roll and the embossing elements of the second embossing roll are arranged such that the embossed elements of the first embossed ply and the embossed elements of the second embossed ply fit into each other similar to a gearing system.

[0086] After the embossed second ply 224 leaves the second embossing nip 215 it is brought into facing relationship with the first ply 205. The two plies 205, 224 are conveyed through the nip 242 formed between the first embossing roll 212 and a marrying roll 240, which may be a steel roll having asubstantially smooth outer surface. The first and second embossed plies 205, 224 are joined together as they pass through the ply bonding nip 242 to form a multi-ply tissue product 280.

[0087] While the aqueous composition may be applied by a series of applicator rolls, as illustrated in FIG. 1, the invention is not so limited. Other means of wetting the pre-strained web may be used such as coaters, rollers or spray applicators or the like can be used. For example, the aqueous composition may be applied to the surface pre-strained tissue ply by rotogravure printing, flexographic printing, spraying, slot coating, blade coating or foam coating. In any case the aqueous composition may be applied continuously or may be applied intermittently such as longitudinal strips or areas. Further, the moistening means can be positioned in various ways so long as it is positioned after the web has been pre-strained and upstream the embossing nip, although it would also be possible to position them at the embossing nip.

[0088] An alternate process for wetting the pre-strained tissue ply is illustrated in FIG. 5. In the illustrated embodiment the first ply 201 is pre-strained by passing the ply 201 though a first nip 210 formed between a counter roll 211 and an embossing roll 212. As the pre-strained ply emerges from the first nip 210 it is treated with an aqueous composition 160 emitted from a spray unit 155, resulting in a wetted and pre-strained web.

[0089] In the illustrated embodiment the aqueous composition 125 is not applied in a pattern, but rather the entirety of the pre-strained ply surface facing the spray unit 110 may be wetted. In such embodiments, the add-on amount of aqueous composition may range from about 1 wt% to about 5 wt%, based upon the bone-dry weight of the first tissue ply. Thereafter the wetted first tissue ply is passed through a second nip 242 formed between the embossing roll 212 and a second backing roll 240 to further strain the wetted first tissue ply and impart an embossing pattern thereon. The wetted and prestrained tissue ply may be combined with a second tissue ply 204 as it passes through the second nip 242 by simultaneously conveying a second ply 204 though the second nip 242. In this manner a two-ply tissue product 280 may be produced.

[0090] The aqueous composition can be applied by a single device of multiple devices may be configured to apply the aqueous composition to the tissue ply. The one or more application devices may apply the same aqueous composition or may be configured to apply different aqueous compositions. In those instances where the process employs a single device it may be configured to apply two or more different aqueous compositions by providing the device with two or more chambers capable of separately delivering the different compositions.

[0091] Moistening of the pre-strained ply can take place preferably with any aqueous composition, such as water, which as noted above may be heated in certain embodiments. In certain instances, theaqueous composition may comprise an adhesive material, while in other instances, it may be devoid of adhesive materials. For example, the liquid can simply be water. In this way, any seepage of the liquid through the structure of the cellulose fibers forming the ply does not cause glue to be left on the surfaces of the mechanical members of the device, such as the embossing roller, simplifying management of the systems, reducing maintenance costs, increasing productivity and quality of the finished product.

[0092] In certain embodiments the aqueous composition may comprise water and one or more additives, such as, for example, an ink or a dye. The addition of a dye may enable the aqueous composition to not only to facilitate wetting of the pre-strained web and improve embossing, but also to obtain patterns visible in the finished tissue product. In this manner the finished product may be imparted with a colored embossing pattern that may be more discernible and desirable to a consumer.

[0093] Where the more than one plies are processed, the wetted tissue ply may be the first or the second tissue ply. In other instances, both a first and a second tissue ply may be wetted prior to being embossed. The same aqueous composition may be configured to treat both the first and the second tissue ply or the separate applicator units may be used to treat the first and the second tissue plies with different aqueous compositions. Regardless of the type of applicator and whether there are one or more applicators are used, the aqueous composition is applied after the web has been pre-strained and while it is in contact with at least a portion of the plurality of male embossing elements. Further, it is generally preferred that the wetted ply does not have sufficient time to dry before embossments are imparted to the web by passing through the second nip.

[0094] TEST METHODS

[0095] Unless otherwise specified, all tests described herein including those described under the Definitions section and the following test methods are conducted on samples that have been conditioned in a conditioned room at a temperature of 23°C±1 °C. and a relative humidity of 50% ±2% for a minimum of 2 hours prior to the test. All plastic and paper board packaging articles of manufacture must be carefully removed from the paper samples prior to testing. The samples tested are “usable units.” “Usable units” as used herein means sheets, flats from roll stock, pre-converted flats, and / or single or multi-ply products. Except where noted all tests are conducted in such conditioned room, all tests are conducted under the same environmental conditions and in such conditioned room. Discard any damaged product. Do not test samples that have defects such as wrinkles, tears, holes, and like. Samples conditioned as described herein are considered dry samples for testing purposes. All instruments are calibrated according to manufacturer's specifications.Basis

[0096] For dry tissue samples, such as embossed tissue products prepared according to the present invention, basis weight is measured by first conditioning the sample as described above. Thereafter, the basis weight of conditioned sample is measured by selecting twelve (12) products (also referred to as sheets) of the sample and making two (2) stacks of sx (6) sheets. In the event the sample consists of perforated sheets of bath or towel tissue, the perforations must be aligned on the same side when stacking the usable units. A precision cutter is used to cut each stack into exactly 10.16 × 10.16 cm (4.0 × 4.0 inch) squares. The two stacks of cut squares are combined to make a basis weight pad of twelve (12) squares thick. The basis weight pad is then weighed on a top loading balance with a minimum resolution of 0.01 grams. The top loading balance must be protected from air drafts and other disturbances using a draft shield. Weights are recorded when the readings on the top loading balance become constant. The mass of the sample (grams) per unit area (square meters) is calculated and reported as the basis weight, having units of grams per square meter (gsm).

[0097] For treated tissue products tissue products prepared according to the present invention, which may have not been subjected to drying after application of an aqueous composition, basis weight is measured as-is. Samples are collected and stored in a sealable bag until testing. Samples are removed from the sealed bag and thereafter stacked, cut and the weight measured as described above.

[0098] Caliper is measured in accordance with TAPPI test methods Test Method T 580 pm-12 " Thickness (caliper) of towel, tissue, napkin and facial products.” The micrometer used for carrying out caliper measurements is an Emveco 200-A Tissue Caliper Tester (Emveco, Inc., Newberg, OR). The micrometer has a load of 2 kilo-Pascals, a pressure foot area of 2,500 square millimeters, a pressure foot diameter of 56.42 millimeters, a dwell time of 3 seconds and a lowering rate of 0.8 millimeters per second.

[0099] Tensile

[0100] Tensile testing is conducted on a tensile testing machine maintaining a constant rate of elongation and the width of each specimen tested is 3 inches. Testing is conducted under TAPPI conditions. Prior to testing samples are conditioned and then cut a 3 ± 0.05 inches (76.2 ± 1.3 mm) wide strip in either the machine direction (MD) or cross-machine direction (CD) orientation using a JDC Precision Sample Cutter (Thwing-Albert Instrument Company, Philadelphia, PA, Model No. JDC 3-10, Serial No. 37333) or equivalent. The instrument used for measuring tensile strengths was an MTS Systems Sintech 11S, Serial No. 6233. The data acquisition software was MTS TestWorks® forWindows Ver. 3.10 (MTS Systems Corp., Research Triangle Park, NC). The load cell was selected from either a 50 Newton or 100 Newton maximum, depending on the strength of the sample being tested, such that the majority of peak load values fall between 10 to 90 percent of the load cell's full-scale value. The gauge length between jaws was 4 ± 0.04 inches (101.6 ± 1 mm) for facial tissue and towels and 2 ± 0.02 inches (50.8 ± 0.5 mm) for bath tissue. The crosshead speed was 10 ± 0.4 inches / min (254 ±1 mm / min), and the break sensitivity was set at 65 percent. The sample was placed in the jaws of the instrument, centered both vertically and horizontally. The test was then started and ended when the specimen broke. The peak load was recorded as either the " MD tensile strength" or the " CD tensile strength" of the specimen depending on direction of the sample being tested. Ten representative specimens were tested for each product or sheet and the arithmetic average of all individual specimen tests was recorded as the appropriate MD or CD tensile strength having units of grams per three inches (g / 3”). Tensile energy absorbed (TEA) and slope are also calculated by the tensile tester. TEA is reported in units of g’cm / cm2and slope is recorded in units of kilograms (kg). Both TEA and Slope are directionally dependent and thus MD and CD directions are measured independently.

[0101] All products were tested in their product forms without separating into individual plies. For example, a 2-ply product was tested as two plies and recorded as such. In the tensile properties of basesheets were measured, the number of plies used varied depending on the intended end use. For example, if the basesheet was intended to be used for 2-ply product, two plies of basesheet were combined and tested.

Claims

We claim:

1. A method of manufacturing an embossed multi-ply tissue product comprising the steps of: a. conveying a first tissue ply having a first surface;b. providing an embossing unit comprising a first embossing roll having an outer surface and a plurality of male embossing elements disposed thereon and arranged to form a first embossing pattern;c. providing a second counter roll in opposition to the first embossing roll thereby forming an embossing nip therebetween;d. contacting a first tissue ply with the outer surface of the first embossing roll and causing the first tissue ply to be deformed by at least a portion of the plurality of male embossing elements disposed thereon to yield a pre-strained first tissue ply;e. applying an aqueous composition to the pre-strained first tissue ply to yield a wetted tissue ply having moisture content greater than the moisture content of the first tissue ply;f. conveying the wetted tissue ply into the embossing nip.

2. The method of claim 1 further comprising the step of providing a first counter roll in opposition to the first embossing roll wherein the first embossing roll and first counter roll are arranged to form a first nip therebetween and the first embossing roll and second counter roll are arranged to form a second nip therebetween.

3. The method of any one of the foregoing claims wherein the basis weight of the wetted first tissue ply is from about 1% to about 10% greater than the first tissue ply.

4. The method of any one of the foregoing claims wherein the aqueous composition comprises at least about 99 wt% water.

5. The method of any one of the foregoing claims wherein the aqueous composition is heated to at least 70°C.

6. The method of any one of the foregoing claims wherein the step of applying an aqueous composition is carried out by spray applicator positioned to apply the aqueous composition before the first ply is conveyed into the first embossing nip.

7. The method of any one of the foregoing claims wherein the spray applicator comprises a nozzle and a reservoir for receiving and storing the aqueous composition.

8. The method of any one of the foregoing claims wherein the amount of aqueous composition applied to the first tissue ply ranges from about 2 wt% to about 3 wt% based upon the dry weight of the first tissue ply.

9. The method of any one of the foregoing claims wherein the aqueous composition is applied to at least about 90% of the surface area of the first tissue ply.

10. The method of any one of the foregoing claims wherein the aqueous composition is applied in a pattern.

11. The method of any one of the foregoing claims wherein the first tissue ply is not dried before being conveyed through the second nip.

12. A method of making an embossed multi-ply tissue product, comprising:a. providing a first tissue ply and a second tissue ply;b. pre-straining the first tissue ply by passing the first tissue ply through a first nip formed between a first backing roll and an embossing roll, the embossing roll having a plurality of first embossing elements arranged in a first embossing pattern on an outer surface thereof;c. while the first tissue ply is supported on the plurality of first embossing elements, applying an aqueous composition to the first tissue ply to provide a wetted first tissue ply having a moisture content greater than that of the first tissue ply prior to step (c); d. passing the wetted first tissue ply through a second nip formed between the embossing roll and a second backing roll to further strain the wetted first tissue ply and impart the first embossing pattern thereto, thereby producing an embossed first tissue ply; and e. bonding the embossed first tissue ply to the second tissue ply by passing the embossed first tissue ply and the second tissue ply through a third nip comprising the embossing roll and a marrying roll, thereby forming a multi-ply tissue.

13. The method of claim 12, wherein the aqueous composition comprises water.

14. The method of claim 12, wherein an add-on amount of the aqueous composition applied in step (c) is from about 1% to about 5% based on a bone-dry weight of the first tissue ply.

15. The method of claim 12, wherein the pre-straining in step (b) is effected by deforming the first tissue ply about tips of the first embossing elements.

16. The method of claim 12, wherein the pre-straining in step (b) produces a calculated local strain of from about 20% to about 50%.

17. The method of claim 12, wherein the first embossing pattern comprises male protuberances having a tip radius, height, sidewall angle, and pitch selected to induce permanent deformation in discrete regions of the first tissue ply.

18. The method of claim 12, wherein the aqueous composition is applied by at least one of spraying, slot-die coating, contact applicator, or misting while the first tissue ply is supported on the first embossing elements.

19. The method of claim 12, wherein the second nip in step (d) is configured to provide a roll-to-roll interference sufficient to impart the first embossing pattern.

20. The method of claim 12, wherein bonding in step (e) is accomplished adhesive application.

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