EP4676732A1

EP4676732A1 - Tissue products with three-dimensional embossing design

Info

Publication number: EP4676732A1
Application number: EP23925605.0A
Authority: EP
Inventors: Massimo CAGNONE; Gabriel F. BOTERO OSPINA
Original assignee: Kimberly Clark Worldwide Inc; Kimberly Clark Corp
Current assignee: Kimberly Clark Worldwide Inc; Kimberly Clark Corp
Priority date: 2023-03-03
Filing date: 2023-03-03
Publication date: 2026-01-14
Also published as: AU2023435807A1; WO2024186306A1; MX2025010119A; KR20250156772A

Abstract

A decorative tissue product is disclosed formed from multiple tissue plies. An embossing pattern is incorporated into at least one of the plies. The embossing pattern creates raised areas on opposite sides of the tissue ply. The embossing design includes billow areas that extend from an exterior surface of the tissue product for forming pillow-like areas. Discontinuous and discrete protrusions are formed in the opposite surface of the tissue ply for assisting in the formation of the billow areas and for attachment to an opposite ply. In one aspect, the internal space of the tissue product remains open for enhancing thickness and softness.

Description

TISSUE PRODUCTS WITH THREE-DIMENSIONAL EMBOSSING DESIGN

BACKGROUND

Consumer tissue products such as facial tissue, bath tissue and paper wipers are generally used to absorb liquids and fluids. Such paper products are predominantly formed of cellulosic papermaking fibers by manufacturing techniques designed specifically to produce several important properties. For example, the products should have good bulk, a soft feel, and should be highly absorbent. Further, the products should also have a pleasant aesthetic appearance and should be resilient against delamination in the environment in which they are used.

In the past, many attempts have been made to enhance certain physical properties of such products. For instance, to enhance the aesthetic appearance, a decorative paper product has been created by embossing a pattern onto one or both sides of the paper web during manufacturing. This standard mechanical embossing resulted in the deformation or breaking of fibers in an attempt to physically press the pattern into the web. In some applications, the resulting embossed patterns were not well-defined and faded as the paper product aged. Also, embossing patterns into tissue webs typically reduce the strength of the web.

In some embodiments, those skilled in the art have used embossing to: increase the thickness of the tissue product, particularly bath tissue. For instance, embossing patterns have been used in order to increase the thickness of multi-ply products in order to improve softness, tactile feel, and roll bulk.

Although patterned tissue products are well known and a wide variety of patterns have been employed, consumers continue to demand visually unique and appealing patterned tissue products. Accordingly, there remains a need for a tissue product, particularly a multi-ply tissue product, having a pattern disposed on a surface of the product that provides consumers with a perception of softness and comfort while also being visually appealing.

SUMMARY

The present disclosure is generally directed to an embossed tissue product The embossed tissue product includes at least two plies. An embossed pattern is formed into at least one of the plies. The embossed pattern produces billow areas or "pillows" on an exterior surface of the product while also producing an open network of passages between adjacent plies. In this manner, the resulting tissue product not only has aesthetic appeal but is also soft to the touch.

In one aspect, for instance, the present disclosure is directed to a tissue product comprising at least a first tissue ply and a second tissue ply. Each ply includes a first surface and a second and opposite surface. An embossing design is formed into the first surface of the first tissue ply. The embossing design includes a pair of spaced apart discontinuous line elements that form protrusions on the second surface of the first tissue ply. The embossing design further includes at least one billow area positioned between the pair of spaced apart discontinuous line elements that extends from the first surface of the first tissue ply (i.e. in an opposite direction than the protrusions). The second surface of the first tissue ply is adhered to the first surface of the second tissue ply by a discontinuous adhesive that is registered with the protrusions on the second surface.

In one aspect, the embossing design includes a plurality of billow areas. The: billow areas converging in order to form enclosed "pillows" on the first surface of the first tissue ply. The spaced apart discontinuous line elements are separate and discrete embossing elements in relation to the billow areas. In one aspect, the protrusions formed by the discontinuous line elements are separated from the billow areas by a plane that is parallel with the first tissue ply and wherein the billow areas comprise raised cells positioned above the plane while the protrusions form an open structure below the plane.

The embossing design can have: an embossing depth that extends from the top of the billow areas on the first surface of the first tissue ply to a top of the protrusions formed by the discontinuous line elements on the second surface of the first tissue ply. The billow areas can have a depth that is greater than about 40%, such as greater than about 45%, such as greater than about 50%, such as greater than about 55%, and less than about 75%, such as less than about 70%, such as less than about 65%, such as less than about 60%. of the embossing depth of the embossing design. In one aspect, the embossing depth can be greater than about 0.6 mm, such as greater than about 0.7 mm, such as greater than about 0.8 mm, and less than about 2 mm, such as less than about 1.5 mm, such as less than about 1.2 mm. The embossing depth, however, can vary based on the product being formed: and can be greater or lesser than the range above.

In one aspect, the embossing design further comprises a pair of spaced apart continuous line elements. The pair of spaced apart discontinuous line elements can be positioned between the pair of continuous line elements. The pair of spaced apart continuous line elements can form raised line elements on the second surface of the first tissue ply. The raised line elements can have the same height as the protrusions formed by the discontinuous line elements or can have a height that is less than the height of the protrusions formed by the discontinuous line elements. The height of the protrusions and the height of the line elements can be measured from the second surface of the first tissue ply. The continuous line elements can be, in one embodiment, parallel or substantially parallel with the discontinuous line elements.

The pair of spaced apart discontinuous line elements can have any suitable shape. The spaced apart discontinuous line elements can be horizontal, vertical or diagonal across the surface of the tissue ply. In one aspect, the discontinuous line elements can be relatively straight. Alternatively, the discontinuous line elements can have a wave pattern. In one aspect, each pair of discontinuous line elements can have a different shape and can converge towards each other without ever intersecting,

The second tissue ply attached to the first tissue ply can be non-embossed and can be a planar sheet. Alternatively, the second ply can be embossed with a pattern.

In one aspect, the first tissue ply and the second tissue ply each contain at least: about 50% by weight pulp fibers, such as softwood fibers, hardwood fibers, or combinations thereof. Each tissue ply can have a bulk of greater than about 5 cc/g, such as greater than about 7 cc/g, such as greater than about 9 cc/g. In one aspect, the embossed tissue product of the present disclosure can be spirally wound into a roll. In one particular embodiment, the tissue product can be a bath tissue.

The present disclosure is also directed to a method for producing a tissue product and to a tissue product made by the method. The method includes passing a first tissue ply having a first surface and a second and opposite surface through a first nip between an engraved roll and an impression roll in order to emboss an embossing design into the first tissue ply. The engraved roll can comprise a pair of spaced apart raised, discontinuous line embossing elements and valley embossing elements positioned between the spaced apart discontinuous line embossing elements. The pair of spaced apart discontinuous line embossing elements can form protrusions on the second surface of the first tissue ply, while the valley embossing elements can form corresponding billow areas that extend from the first surface of the first tissue ply. The embossed first tissue ply can be Contacted with an adhesive applicator for applying adhesive to the protrusions formed by the spaced apart discontinuous embossing elements. The first tissue ply and a second tissue ply can be passed through a second nip formed by a marrying roll to adhere the second tissue ply to the first tissue ply where the protrusions are: located.

Other features and aspects of the present disclosure are discussed in greater detail below.

BRIEF DESCRIPTION OF THE DRAWINGS

A full and enabling disclosure of the present disclosure is set forth more particularly in the remainder of the specification, including reference to the accompanying figures, in which:

Figure 1 is a plan view of one embodiment of a tissue product made in accordance with the present disclosure;

Figure 2 is a schematic illustration of an apparatus and process for embossing a tissue product in accordance with the present disclosure;

Figure 3 is a cross-sectional view of one embodiment of an embossing pattern that may be used to produce tissue products in accordance with the present disclosure; Figure 4 is a cross-sectional view illustrating a tissue ply being embossed in accordance with the present disclosure; and

Figure 5 is a cross-sectional view of the tissue product illustrated in Figure 1.

Repeat use of reference characters in the present specification and drawings is intended to represent the same or analogous features or elements of the present invention.

DEFINITIONS

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 “Fibrous Structure” refers to a structure comprising a plurality of elongated particulate having a: length to diameter ratio greater than about 10 such as, for example, papermaking fibers and more particularly pulp fibers, including both wood and non-wood pulp fibers, and synthetic staple fibers, A non-limiting example of a fibrous structure is a tissue web comprising pulp fibers.

As used herein the term "Tissue Web" or “Tissue Ply" refers to a fibrous structure provided in sheet form and being suitable for forming a tissue product.

As used herein the term "Tissue Product” refers to products made from tissue webs and includes, bath tissues, facial tissues, paper towels, industrial wipers, foodservice wipers, napkins, medical pads, and other similar products. Tissue products may comprise one, two, three or more plies.

As used herein the term "Pattern" generally refers to the arrangement of one or more design elements. Within a given pattern the design elements may be the same or may be different, further the design elements may be the: same relative size or may be different sizes. For example, in one embodiment, a single design element may be repeated in a pattern, but the size of the design element may be different from one design element to the next within the pattern.

As used herein, the term "Embossing Pattern or Design" generally refers to a decorative Shape disposed across at least one dimension of a fibrous structure surface, the pattern may comprise a line element, discrete elements or other shapes. The embossing pattern comprises a portion of the fibrous structure lying out of plane with the surface plane of the fibrous structure. In general, the embossing pattern results from embossing the fibrous structure resulting in protrusions having a z- directional elevation on one side of the fibrous structure and raised areas on the opposite side of the fibrous structure.

As used herein the term "Line Element” refers to an element, such as an embossing element, in the shape of a line, which may be continuous ordiscontinuous, such as discrete or interrupted. The line element may be of any suitable shape Such as straight, bent, kinked, curled, curvilinear, serpentine, sinusoidal, and mixtures thereof that may form a regular or irregular, periodic or nonperiodic lattice work of structures wherein the line element exhibits a length along its path of at least 10 mm. in one example, the line element may comprise a plurality of discrete elements, such as dots and/or dashes for example, that are oriented together to form a line element.

As used herein the term "Continuous Element" refers to an element, such as an embossing element, disposed on a fibrous structure that extends without interruption throughout one dimension of the fibrous structure.

As used herein the term "Discrete Element" refers to an element, such as an embossing element, disposed On a fibrous structure that does not extend continuously in any dimension of the fibrous structure.

As used herein the term "Basis Weight" (BW) generally refers to the bone dry weight per unit area of a tissue and is generally expressed as grams per square meter (gsm), Basis weight is measured using TAPPI test method T-220. While basis weight may be varied, tissue products prepared according to the present invention generally have a basis weight greater than about 10 gsm, such as from about 10 to about 80 gsm and more preferably from about 30 to about 60 gsm.

As used herein, the term “caliper" is the representative thickness of a single sheet (caliper of tissue products comprising two or more plies is the thickness of a single sheet of tissue product comprising all plies) measured in accordance with TAPPI test method T402 using a ProGage 500 Thickness Tester (Thwing-Albert Instrument Company, West Berlin, NJ.). The micrometer has an anvil diameter of 2.22 inches (56.4 mm) and an anvil pressure of 132 grams per square inch (per 6,45 square centimeters) (2.0 kPa). The caliper of a tissue product may vary depending on a variety of manufacturing processes and the number of plies in the product, however, tissue products prepared according to the present invention generally have a caliper greater than about 100 μm, more preferably greater than about 200 μm and still more preferably greater than about 300 μm, such as from about 100 to about 1 ,000 μm.

As used herein the term “Sheet Bulk” refers to the quotient of the caliper (generally having units of μm) divided by the bone dry basis weight (generally having units of gsm). The resulting sheet bulk is expressed in cubic Centimeters per gram (cc/g), While sheet bulk may vary depending on any one of a number of factors, tissue products prepared according to the present invention may have a sheet bulk greater than about 5.0 cc/g, more preferably greater than about 10.0 cc/g and still more preferably greater than about 12.0 cc/g, such as from about 5.0 to about 20.0 cc/g.

DETAILED DESCRIPTION

It is to be understood by one of ordinary skill in the art that the present discussion is a description of exemplary embodiments only and is not intended as limiting the broader aspects of the present disclosure.

In general, the present disclosure is directed to a tissue product including an embossing design that provides a three-dimensional, aesthetically pleasing effect. The embossing design can be incorporated into any suitable tissue product, such as a bath tissue. Once applied to a tissue product, the embossing design increases the thickness of the product, can improve cleaning, can have a softer feel, and can have: the appearance of a premium high qualify product.

The embossing design of the present disclosure includes raised areas that extend from one surface of a tissue ply and raised areas that extend from an opposite surface of the tissue ply. On one side of the tissue ply, billow areas or "pillows” are formed that not only have aesthetic appeal but can also provide softness and a cushioning effect. The embossments: oh the other side of the tissue ply, on the other hand, provide a means for attaching the embossed ply to an adjacent ply and also create an open structure between the first tissue ply and the second tissue ply. Ultimately, a multi-ply tissue product is formed that has a z-direction of expansion that provides numerous advantages and benefits.

Improved properties and characteristics of tissue products are created in accordance with the present disclosure using an embossing design that causes raised areas to form on opposite sides of a tissue ply. Once attached to an adjacent tissue ply, the resulting tissue product has a unique pattern that provides the product not only with a distinctive look that is appealing to consumers, but also with, in one aspect, an enhanced thickness and tactile feel that are also highly desirable.

As will be described in greater detail below, in one aspect, in order to produce tissue products made in accordance with the present disclosure, a tissue ply is embossed by an engraved roll that applies an embossing pattern to the tissue ply. The engraved roll can be used in an embossing process that includes an adhesive lamination step that adhesively laminates the embossed tissue ply to an adjacent tissue ply. The adhesive can be applied selectively and intermittently for adhering the two plies together. For example, in one embodiment, the adhesive can be coordinated with protrusions on the embossed ply that is then used to adhere the two plies together in a manner that produces internal free space.

Referring to FIGS. 1 and 5, for instance, one embodiment of a tissue product made in accordance with the present disclosure is shown. The embodiment illustrated in FIGS. 1 and 5 is merely exemplary and the teachings of the present disclosure can be applied to many different patterns for creating all different types of look. FIG. 1 illustrates a perspective view of the embossing design from a surface of the tissue product while FIG. 5 is a cross-section of the design.

Referring to FIGS. 1 and 5, a multi-ply tissue product 10 made in accordance with the present disclosure is shown. In FIG. 1, the surface of a top tissue ply 12 is illustrated. An embossing design in accordance with the present disclosure has been formed into the surface of the top ply 12. The: embossing design includes repeating elements. Further, the embossing design illustrated in FIG. 1 includes two different embossing patterns.

As shown, the first pattern of the embossing design includes pairs of spaced apart discontinuous line elements 14. Positioned between each pair of discontinuous line elements 14 are billow areas 16. The billow areas 16 extend outwardly from the surface of the tissue ply 12 and form pillow-like structures. As shown in FIG. 1, for instance, the. spaced apart line elements 14can converge which creates cells for the billow areas 16.

Optionally, the embossing design can further include pairs of continuous line elements 18, As shown, the line elements 18 border the spaced apart discontinuous line elements 14. In other words, the discontinuous line elements 14 are positioned between the pair of spaced apart continuous line elements 18. In addition, in one aspect, the discontinuous line elements can be parallel or have the same shape as the continuous line elements 18.

As will be explained in greater detail below, the billow areas 16 form raised areas on the exterior surface of the tissue ply 12. The discontinuous line elements 14 and the continuous line elements 18, on the other hand , form raised areas that extend Into the interior of the tissue product. For example, as shown in FIG. 5, the tissue ply 12 includes a planar surface 20. The billow areas 16 extend outwardly from the plane 20. The discontinuous line elements 14, on the other hand, form protrusions 22 that extend in an opposite direction from the billow areas 16. Similarly, the continuous line elements 18 form continuous embossed lines that also extend in a direction opposite the billow areas 16.

As shown in FIG. 5, the first tissue ply 12 is laminated to a second tissue ply 24 to form the tissue product 10. In one aspect, the first tissue ply 12 is adhered to the second tissue ply 24 by a discontinuous adhesive pattern that is registered with the protrusions 22. As shown in FIG. 5, for instance, an adhesive 26 can be applied to the protrusions 22 for attaching the two plies together, In this embodiment, the embossing design and discontinuous application of the adhesive produces a tissue product 10 with an open interior space that allows for air flow and enhanced thickness. For instance, when the adhesive 26 is only applied to the protrusions 22, air can flow around the protrusions as shown in FIG. 1 and can flow between the two plies. For example, in one embodiment, the embossing design can be constructed so that there are no closed cells formed between the two tissue plies when the first ply 12 is laminated to the second ply 24.

As shown in FIG. 5, the second tissue ply 24 can generally have a planar structure. For example, the second ply 24 can comprise a non-embossed tissue ply. Alternatively, the second ply 24 can also include an embossing design. In one aspect, for instance, the same embossing design can be embossed into the second ply 24 such that the protrusions from one ply are adhered to the protrusions of an opposite ply.

Referring back to FIG. 1, the embossing design illustrated on the tissue product 10 can also include non-embossed areas 28, The non-embossed areas 28 are located between adjacent pairs of continuous: line elements 18. In the embodiment illustrated in FIG. 1 , the discontinuous line elements 14, the continuous line elements 18, and the non-embossed areas 28 have a wave-like shape. In addition, the pattern includes converging and diverging areas in order to provide a three-dimensional appearance. The converging and diverging wave pattern also helps shape and develop the billow areas 16. As shown in FIG. 1, the billow areas 16 are positioned between non-embossed areas 28 providing the product with a unique pattern of expanded areas in the z-directlon followed by planar areas.

The tissue product 10 of the present: disclosure can include multiple embossing designs in order to further enhance the appearance. For example, as shown in FIG. 1, the tissue product 10 includes a second embossing design comprised of discrete shapes 30. In the embodiment illustrated, the discrete shapes are in the form of puppies. Any suitable aesthetic design can be incorporated into the embossing pattern. In addition, brand names, logos, and the like can also be incorporated into the embossing design that become visible to the user.

Referring to FIGS. 2-4, one embodiment of a process for producing tissue products in accordance with the present disclosure is shown. Referring to FIG. 2, a first tissue ply 12 is conveyed past a series of idler rollers 122 towards a nip 124 that is located: between an engraved: roll 126 and an impression roll 128. The engraved roll 126 rotates in a counterclockwise direction while the: impression roll 128 rotates in a clockwise direction. The first tissue ply 12 forms the top ply in the resulting multi-ply tissue product 10 as shown in FIG. 1.

The engraved roll 126 is generally a hard and non-deformable roil, such as a steel roll. The impression roll 128 may be a substantially smooth roll and can be a smooth roll having a covering, or made of, natural or Synthetic rubber. The natural or synthetic rubber, for instance, can be polybutadiene or copolymers of ethylene and propylene or the like. In one aspect, the impression roll 128 has a hardness of greater than about 40 Shore A, such as from about 40 Shore A to about 100 Shore A including all increments of 1 Shore A therebetween. For example, in one aspect, the hardness of the impression roll 128 can be from about 40 Shore A to about 80 Shore A.

The impression roll 128 and the engraved roll 126 are urged together to form the nip 124 through which the first tissue ply 12 passes to impose an embossed design on the web. The engraved roll 126 comprises various embossing elements that include raised areas and cavities or depressions that together form the embossing design as shown in FIG. 1. Referring to FIG. 3, an enlarged cross-section of the engraved roll 126 is shown. As illustrated, the embossing design includes a pair of spaced apart discontinuous line embossing elements 32 and 34. As shown in FIG. 1 , the embossing elements 32 and 34 form the discontinuous line elements 14. More particularly, the embossing elements 32 and 34 form protrusions on the opposite side of the tissue ply as the tissue ply is brought into contact with the engraved roll 126. The discontinuous line embossing elements 32 and 34 can have any suitable shape. For instance, the top surface of the embossing elements 32 and 34 can be circular, elliptical, ovals, dashes, bars, squares, triangles, and the like. In one aspect, the top surface of the embossing elements 32 and 34 are circular.

The discontinuous line embossing elements 32 and 34 can have the same shape or can have a different shape. In the embodiment illustrated in FIG. 3, for instance, the embossing element 34 has a dimension, such as a width or diameter, that is smaller than the embossing element 32. The embossing elements 32 and 34, however, can have the same height 42.

The engraved roll 126 can also optionally include continuous line embossing elements 36 and 38. As shown, the discontinuous line embossing elements 32 and 34 are positioned between the continuous line embossing elements 36 and 38. The continuous line embossing elements 36 and 38 form embossing lines into a tissue ply contacted with the engraved roll 126, The continuous line elements form raised areas on a surface of the tissue ply opposite the surface that contacts the embossing roll 126.

The continuous line embossing elements 36 and 38 can generally have the same dimensions or can have different dimensions. The continuous line embossing elements 36 and 38 have a height that is the same or less than the height of the discontinuous line embossing elements 32 and 34. in accordance with the present disclosure, the embossing design as shown in FIG. 3 further includes valley embossing elements 40 that extend below the plane 44 of the engraved roll 126. The valley embossing elements 40 form raised areas on the same side of the tissue ply that contacts the engraved roll 126. Thus, embossments created by the valley embossing elements 40 extend in ah opposite direction from the embossments formed by the discontinuous line embossing elements 32 and 34 and the continuous line embossing elements 36 and 38. The valley embossing elements 40 form the billow areas 16 as shown in FIG. 1 , For example, in one embodiment, the valley embossing elements 40 converge to form discrete cells within the surface of the engraved roll 126. Ultimately, the valley embossing elements 40 form pillow-like extensions on the exterior surface of the tissue product 10.

As shown in FIG. 3, in one aspect, the valley embossing elements 40 are separate and: distinct embossing elements in comparison to the discontinuous line embossing elements 32 and 34. In particular, the valley embossing elements 40 can be spaced and positioned between the pair of opposing discontinuous line embossing elements 32 and 34. For example, in one aspect, as shown in FIG. 3, the valley embossing elements do not share common walls with the pair of spaced apart discontinuous line embossing elements 32 and 34. This arrangement can help better form the billow areas on the exterior surface of the tissue product and allow for more dramatic pillow-like areas to form.

As shown in FIG. 3, the embossing design on the engraved roll 126 has an embossing height 46. The embossing height 46 extends from a top surface of the discontinuous line embossing elements: 32 and 34 to the bottom surface of the valley embossing elements 40. The overall height or depth of the embossing design can be generally greater than about 0,6 mm, such as greater than about 0,7 mm, such as greater than about 0.8 mm, and less than about 2 mm, such as less than about 1.5 mm, such as less than about 1 ,2 mm. The above dimensions, however, are merely exemplary. These: dimensions can be increased or decreased depending upon the tissue web being embossed and the product being formed. For instance, the embossing height or depth can be increased if applied to a tissue product with a greater basis weight.

In general, the depth of the valley embossing elements is at least about 40% of the embossing depth 46. More particularly, the depth of the valley embossing elements 40 measured from the plane 44 is greater than about 45%, such as greater than about 50%, such as greater than about 55%, and generally less than about 75%, such as less than about 70%, such as less than about 65%, such as less than about 60% of the total embossing depth 46.

Referring back to FIG. 2, typically the engraved roll 126 will include many more embossing elements than that shown in the figure. Further, as described above, the engraved roll 126 can include additional embossing patterns. For instance, the engraved roil 126 can include a second embossing pattern, a third embossing pattern, and/or a fourth embossing pattern that operate in conjunction with the embossing pattern illustrated in FIG. 3. For example, as shown in FIG. 1, a second embossing pattern can incorporate discrete shapes 30 that become visible on the product.

With continued reference to FIG. 2, force or pressure, is applied to one or both of the rolls 126 and 128 such that the rolls are urged against one another to form the nip 124. The pressure causes the impression roll 128 to deform about the embossing elements 32, 34, 36, 38 and 40 such that when the tissue ply 12 is pressed about the embossing elements 32, 34, 36, 38 and 40, an embossing design is formed into the tissue ply 12 such that raised billow areas 16 form on one side of the tissue ply 12 and discontinuous line elements 14 and continuous line elements 18 form on an opposite side of the tissue ply.

To form a two-ply tissue product, a second tissue ply 24 is conveyed around an idler roller 142 and then pressed into a nip 144 located between a substantially smooth roll 146 which may be made of rubber and a marrying roll 148, which may be a steel roll. The second tissue ply 24 is adapted to form the bottom ply in the resulting multi-ply tissue product 10. As it is conveyed, the second tissue ply 24 passes through a second nip 150 created between the engraved roll 126 and the marrying roll 148 where it is brought into contact with the first tissue ply 12, which now bears the embossing design as a result of being embossed by the engraved roll 126. The first and second plies 12 and 24 are joined together as they pass through the nip 150 to form a: multi-ply tissue product 10.

As shown in FIG. 2, in certain embodiments, after the first tissue ply 12 passes through the nip 124 between the engraved roll 126 and the impression roll 128, an adhesive unit 152 can apply an adhesive to the distal ends of protrusions on the opposite surface of the tissue ply 1.2 that is in contact with the engraved roll 126. In one aspect, the adhesive unit 152 is positioned and configured only to apply adhesive to the spaced apart discontinuous line elements 14 on the first tissue ply 12 Alternatively, the adhesive unit 152 can also apply adhesive to the distal ends of the continuous line elements 18. In one embodiment, however, the height of the continuous line elements 18 is less than the height of the spaced apart discontinuous line elements 14 for avoiding application of the adhesive.

The embossed first tissue ply 12 with the applied adhesive then advances further to the nip 150 between the engraved roll 126 and the marrying roll 148. At this point, the hon-embossed second ply 24 is attached to the embossed first ply 12 and both plies are then conveyed around the marrying roll 148 to form the two-ply tissue product 10 which is Subsequently spirally wound into a roll (not shown).

Through the above process, a tissue product 10 can be formed as Shown in FIG. 1. The tissue product 10 can comprise a two-ply tissue product in which the first ply 12 is the embossed ply that forms the top of the product. The second ply 12, on the other hand, can be a non-embossed ply that remains relatively planar and forms the bottom surface of the product.

Referring to FIG. 4, the nip 124 is shown in greater detail formed between the engraved roll 126 and the impression roll 128. FIG. 4 shows the first tissue ply 12 being embossed within the nip 124 which is then subsequently joined to the second tissue ply 24. The engraved roll 126 includes the embossing elements 32, 34, 36, 38 and 40 which then forms the continuous line elements 18, the discontinuous line elements 14 and the billow areas 16 in the first tissue ply 12.

In certain embodiments, to improve processability and one or more physical properties, one or more of the fibrous plies may be subjected to preconditioning to impart moisture and/or heat to the tissue plies prior to entering an embossing nip. For example, preconditioning mechanisms may be positioned upstream of the nip located between the engraved roll and the impression role to introduce moisture and/or heat to the first tissue ply prior to embossing. Methods and arrangements for applying moisture and heat (e.g., steam) to tissue webs are known to skilled artisans, and can be employed and fall within the scope of the present invention. By way of example, steam can be applied to either or both sides of a web prior to embossing.

In general, any suitable tissue web can be embossed in accordance with the present disclosure and incorporated into the tissue product 10. Bath tissue, facial tissue, paper towels, industrial wipers, and the like can be formed in accordance with the present disclosure. The tissue product 10 can be packaged as individual sheets contained in a dispenser or can be offered to consumers in the form of a spirally wound roll. Tissue products and the tissue plies incorporated into the product can generally have a bulk density of greater than about 3 cc/g, such as greater than about 5 cc/g, such as greater than about 6 cc/g, such as greater than about 7 cc/g, such as greater than about 8 cc/g, such as greater than about 9 cc/g, such as greater than about 10 cc/g, and generally less than about 20 cc/g.

Fibers suitable for making tissue webs comprise any natural or synthetic cellulosic fibers including, but not limited to nonwoody fibers, such as cotton, abaca, kenaf, sabai grass, flax, esparto grass, straw, jute hemp, bagasse, milkweed floss fibers, and pineapple leaf fibers; and woody or pulp fibers such as those obtained from deciduous and coniferous trees, including softwood fibers, such as northern and southern softwood kraft fibers; hardwood fibers, such as eucalyptus, maple, birch, and aspen. Pulp fibers can be prepared in high-yield or low-yield forms and can be pulped in any known method, including kraft, sulfite, high-yield pulping methods and other known pulping methods. Fibers prepared from organosolv pulping methods can also be used, including the fibers and methods disclosed in U.S. Pat. No. 4,793,898, issued Dec. 27, 1988 to Laamanen et al.; U.S. Pat. No. 4,594,130, issued Jun. 10, 1986 to Chang et al.; and U.S. Pat. No. 3,585,104. Useful fibers can also be produced by anthraquinone pulping, exemplified by U.S. Pat. No. 5,595,628 issued Jan. 21, 1997, to Gordon et al.

A portion of the fibers, such as up to 50% or less by dry weight, or from about 5% to about 30% by dry weight, can be synthetic fibers such as rayon, polyolefin fibers, polyester fibers, bicomponeht sheath-core fibers, multi-component binder fibers, and the like, An exemplary polyethylene fiber is Pulpex®, available from Hercules, Inc. (Wilmington, Del.). Any known bleaching method can be used. Synthetic cellulose fiber types include rayon in all its varieties and other fibers derived from viscose or chemically-modified cellulose.

Chemically treated natural cellulosic fibers can be used such as mercerized pulps, chemically stiffened or crosslinked fibers, or sulfonated fibers. For good mechanical properties in using papermaking fibers, it can be desirable that the fibers be relatively undamaged and largely unrefined or only lightly refined. While recycled fibers can be used, virgin fibers are generally useful for their mechanical properties and lack of contaminants. Mercerized fibers, regenerated cellulosic fibers, cellulose produced by microbes, rayon, and other cellulosic material or cellulosic derivatives can be used. Suitable papermaking fibers can also include recycled fibers, virgin fibers, or mixes thereof. In certain embodiments capable of high bulk and good compressive properties, the fibers can have a Canadian Standard Freeness of at least 200, more specifically at least 300, more specifically still at least 400, and most specifically at least 500.

Other papermaking fibers that can be used in the present disclosure include paper broke or recycled fibers and high yield fibers. High yield pulp fibers are those papermaking fibers produced by pulping processes providing a yield of about 65% or greater, more specifically about 75% or greater, and still more specifically about 75% to about 95%. Yield is the resulting amount of processed fibers expressed as a percentage of the initial wood mass. Such pulping processes include bleached chemithermomechanical pulp (BCTMP), chemithermomechanical pulp (CTMP), pressure/pressure thermomechanical pulp (PTMP), thermomechanical pulp (IMP), thermomechahical chemical pulp (TMCP), high yield sulfite pulps, and high yield Kraft pulps, all of which leave the resulting fibers with high levels of lignin. High yield fibers are Well known for their stiffness in both dry and wet States relative to typical chemically pulped fibers.

In general, any process capable of forming a paper web can also be utilized in the present disclosure. For example, a papermaking process of the present disclosure can utilize creping, wet creping, double creping, embossing, wet pressing, air pressing, through-air drying, creped through-air drying, uncreped through-air drying, hydroentangling, air laying, as well as other steps known in the art.

The tissue web may be formed from a fiber furnish containing pulp fibers in an amount of at least about 50% by weight, such as at least: about 60% by weight, such: as at least about 70% by weight, such as at least about 80% by weight, such as at least about 90% by weight, such as 100% by weight.

The tissue web can also be formed without a substantial amount of inner fiber-to-fiber bond strength. In this regard, the fiber furnish used to form the base web can be treated with a chemical debonding agent. The debonding agent can be added to the fiber slurry during the pulping process or can be added directly to the headbox. Suitable debonding agents that may be used in the present disclosure include cationic debonding agents such as fatty dialkyl quaternary amine salts, mono fatty alkyl tertiary amine salts, primary amine salts, imidazoline quaternary salts, silicone quaternary salt and unsaturated fatty alkyl amine salts. Other suitable debonding agents are disclosed in U.S. Pat. No, 5,529,665 to Kaun which is incorporated herein by reference. In particular, Kaun discloses the use of cationic silicone compositions as debonding agents. In one embodiment, the debonding agent used in the process of the present disclosure is an organic quaternary ammonium chloride and, particularly, a silicone-based amine salt of a quaternary ammonium chloride, For example, the debonding agent can be PROSOFT® TQ1003, marketed by the Hercules Corporation, The debonding agent can be added to the fiber Slurry in an amount of from about 1 kg per metric tonne to about 10 kg per metric tonne of fibers present within the slurry.

In an alternative embodiment, the debonding agent can be an imidazoline-based agent. The imidazoline-based debonding agent can be obtained, for instance, from the Witco Corporation. The imidazoline-based debonding agent can be added in an amount of between 2.0 to about 15 kg per metric tonne.

In one embodiment, the debonding agent can be added to the fiber furnish according to a process as disclosed in PCT Application having an International Publication No. WO 99/34057 filed on Dec. 17, 1998 or in PCT Published Application having an International Publication No. WO 00/66835 filed on Apr. 28, 2000, which are both incorporated herein by reference. In the above publications, a process is disclosed in which a chemical additive, such as a debonding agent, is adsorbed onto cellulosic papermaking fibers at high levels. The process includes the steps of treating a fiber slurry with an excess of the chemical additive, allowing sufficient residence time for adsorption to occur, filtering the slurry to remove unadsorbed chemical additives, and redispersing the filtered pulp with fresh water prior to forming a nonwoven web.

Optional chemical additives may also be added to the aqueous papermaking furnish or to the formed embryonic web to impart additional benefits to the product and process and are not antagonistic to the intended benefits of the invention. The following materials are included as examples of additional chemicals that may be applied to the web along with the additive composition of the present invention. The chemicals are included as examples and are not intended to limit the scope of the invention. Such chemicals may be added at any point in the papermaking process, including being added simultaneously with the additive composition in the pulp making process, wherein said additive or additives are blended directly with the additive composition.

Additional types of chemicals that may be added to the paper web include, but is not limited to, absorbency aids usually in the form of cationic, anionic, or non-ionic surfactants, humectants and plasticizers such as low molecular weight polyethylene glycols and polyhydroxy compounds such as glycerin and propylene glycol. Materials that supply skin health benefits such as mineral oil, aloe extract, vitamin e, silicone, lotions in general and the like may also be incorporated into the finished products.

In general, the products of the present invention can be used in conjunction with any known materials and chemicals that are not antagonistic to its intended use. Examples of such materials include but are not limited to odor control agents, such as odor absorbents, activated carbon fibers and particles, baby powder, baking soda, chelating agents, zeolites, perfumes or other odor-masking agents, cyclodextrin compounds, oxidizers, and the like. Superabsorbent particles, synthetic fibers, or films may also be employed. Additional options include cationic dyes, optical brighteners, humectants, emollients, and the like.

Tissue webs that may be treated in accordance with the present disclosure may include a single homogenous layer of fibers or may include a stratified or layered construction. For instance, the tissue web ply may include two or three layers of fibers.

The basis weight of tissue webs made in accordance with the present disclosure can vary depending upon the final product. For example, the process may be used to produce bath tissues, facial tissues, paper towels, industrial wipers, and the like. In general, the basis weight of the tissue products may vary from about 10 gsm to about 110 gsm, such as from about 20 gsm to about 90 gsm. For bath tissue and facial tissues, for instance, the basis weight may range from about 10 gsm to about 40 gsm, For paper towels, on the other hand, the basis weight may range from about 25 gsm to about 80 gsm.

In multiple ply products, the basis weight of each tissue web present in the product can also vary. In general, the total basis weight of a multiple ply product will generally be the same as indicated above, such as from about 20 gsm to about 110 gsm. Thus, the basis weight of each ply can be from about 10 gsm to about 60 gsm, such as from about 20 gsm to about 40 gsm.

These and other modifications and variations to the present invention may be practiced by those of ordinary skill in the art, without departing from the spirit and scope of the present invention, which is more: particularly set forth in the appended claims. In addition, it should be understood that aspects of the various embodiments may be interchanged both in whole or in part. Furthermore, those of ordinary skill in the art will appreciate that the foregoing description is by way of example only and is not intended to limit the invention so further described in such appended claims.

Claims

What Is Claimed:

1. A tissue product comprising: a first tissue ply including a first surface and a second and opposite surface; a second tissue ply including a first surface and a second and opposite surface; an embossing design formed into the first tissue ply, the embossing design including a pair of spaced apart discontinuous line elements that form protrusions on the second surface of the first tissue ply and at least one billow area positioned between the pair of spaced apart discontinuous line elements, the at least one billow area forming a raised area on the first Surface of the first tissue ply; and wherein the second surface of the first tissue ply is adhered to the first surface of the second tissue ply by a discontinuous adhesive registered with the protrusions on the second surface of the first tissue ply,

2. A tissue product as defined in claim 1 , wherein the billow areas converge in order to form enclosed areas on the first surface of the first tissue ply.

3. A tissue product as defined in any of the preceding claims, further comprising a pair of spaced apart continuous line elements, the pair of spaced apart discontinuous line elements being positioned between the pair of spaced apart continuous line elements.

4. A tissue product as defined in claim 3, wherein the pair of spaced apart continuous line elements form raised continuous line elements on the second surface of the first tissue ply. .

5. A tissue product as defined in claim 4, wherein the raised continuous line elements have about the same height as the protrusions formed by the discontinuous line elements.

6. A tissue product: as defined in claim 4, wherein the protrusions formed by the discontinuous line elements have a height extending from the second surface of the first tissue ply that is greater than a height of the raised continuous line elements.

7. A tissue product as defined in any of the preceding claims, wherein the embossing design has an embossing depth that extends from a top of the billow areas to a fop of the protrusions formed by the discontinuous line elements, the billow areas having a height that is greater than about 40%, such as greater than about 45%, such as greater than about 50%, such as greater than about 55%, and less than about 70%, such as less than about 65% of the embossing depth of the: embossing design.

8. A tissue product as defined in claim 7, wherein the embossing design has an embossing depth of greater than about 0.6 mm, such as greater than about 0.7 mm, such as greater than about 0.8 mm, and less than about 2 mm, such as less than about 1.5 mm, such as less than about 1.2 mm.

9. A tissue product as defined in any of the preceding claims, wherein the second tissue ply is a non-embossed sheet.

10. A tissue product as defined in claim 3 or 4, wherein the spaced apart discontinuous line elements are substantially parallel with the Spaced apart continuous line elements.

11. A tissue product as defined in any of the preceding claims, wherein the spaced apart discontinuous line elements form a wave pattern on the first tissue ply.

12. A tissue product as defined in any of the preceding claims, wherein the spaced apart: discontinuous line elements are separate and discrete embossing elements in relation to the billow areas.

13. A tissue product as defined in any of the preceding claims, Wherein the protrusions formed by the discontinuous line elements are separate from the billow areas by a plane that is parallel with the first tissue ply, the billow areas forming cells above the plane, the protrusions formed by the discontinuous line elements forming an open structure below the plane.

14. A tissue product as defined in any of the preceding claims, wherein the spaced apart discontinuous line elements never intersect.

15. A tissue product as defined in any of the preceding claims, wherein the first tissue ply and the second tissue ply each Comprise at least 50% by weight pulp fibers, each ply having a bulk of greater than about 5 cc/g, such as greater than about 7 cc/g, such as greater than about 9 cc/g.

16. A tissue product as defined in any of the preceding claims, wherein the first tissue ply and second tissue ply are spirally wound into a roll.

17. A tissue product as defined in any of the preceding claims, wherein the tissue product comprises a bath tissue.

18. A tissue product made by a process comprising: passing a first tissue ply having a first surface and a second and opposite surface through a first nip between an engraved roll and an impression roll in order to emboss an embossing design into the first tissue ply, the engraved roll comprising a pair of spaced apart raised, discontinuous line embossing elements and valley embossing elements positioned between the spaced apart discontinuous line embossing elements; contacting the embossed first tissue ply with an adhesive applicator for applying adhesive to protrusions formed by the spaced apart discontinuous embossing elements; and passing the first tissue ply and a second tissue ply through a second nip formed by a marrying roll to adhere the second tissue ply to the first tissue ply where the protrusions are located.

19. A tissue product as defined in claim 18, wherein the engraved roll includes an embossing depth that extends from the valley embossing elements to a top of the spaced apart discontinuous line embossing elements, the valley embossing elements having a depth that is greater than about 40%, such as greater than about 45%, such as greater than about 50%, such as greater than about 55%, and less than about 70%, such as less than about 65%, such as less than about 60% of the embossing depth.

20. A tissue product as defined in claim 18, wherein the spaced apart discontinuous line embossing elements: do not share a common wall with the valley embossing elements.