US20150176219A1

US20150176219A1 - Sanitary Tissue Products Comprising a Surface Pattern

Info

Publication number: US20150176219A1
Application number: US14/576,242
Authority: US
Inventors: Lynne Cheryl Hannen; Andre Mellin; Devin William Baldridge
Original assignee: Procter and Gamble Co
Current assignee: Procter and Gamble Co
Priority date: 2013-12-20
Filing date: 2014-12-19
Publication date: 2015-06-25
Also published as: CA2875801A1

Abstract

Sanitary tissue products having a surface pattern for better wet properties and/or cleaning properties.

Description

FIELD OF THE INVENTION

The present invention relates to surface patterns utilized on sanitary tissue products, and more particularly to sanitary tissue products comprising surface patterns, for example a 3D patterns, which can be formed for example by embossing the sanitary tissue product or fibrous structure employed therein with the surface pattern and/or molding the surface pattern into the sanitary tissue products and/or fibrous structures, such as by wet molding and dry molding onto a molding member comprising the surface pattern.

BACKGROUND OF THE INVENTION

Surface patterns having repeating design elements have been used on sanitary tissue products for many years. Most surface patterns have been created by embossing a pattern into a surface of the sanitary tissue product. Some have been created by wet forming, such as molding an embryonic fibrous structure onto a belt comprising a three-dimensional resin pattern that gets imparted to a surface of a fibrous structure and ultimately the sanitary tissue product formed from the fibrous structure.
In the past, as shown in prior art FIGS. 1 and 2, an example of a sanitary tissue product 10 comprises a surface pattern 12 on a surface 14 of the sanitary tissue product 10. The surface pattern 12 comprised a set of lines 16 comprising a plurality of discrete depressions 18, such as dots and/or dashes, which may be embossments and/or may be wet formed. The discrete depressions 18 were of generally the same size long the length of the lines 16. Further, the set of lines 16 were arranged such that a node 20 was formed between the lines 16. A single or double rhombus element 22 was positioned within the node 20.
Consumers of sanitary tissue products, for example paper towels, that comprised surface patterns such as those shown in FIGS. 1 and 2, still desired sanitary tissue products that convey better wet properties and/or wet usage and/or better cleaning, such as soil removal and/or soil dislodging, than prior sanitary tissue products.
Therefore, the problem faced by formulators is how to make a sanitary tissue product, for example a paper towel, having a surface pattern that conveys better wet properties and/or wet usage and/or better cleaning, such as soil removal and/or soil dislodging, than known surface patterns on sanitary tissue products.
Accordingly, there is a need for a sanitary tissue product comprising a surface pattern that conveys better wet properties (i.e., the paper towel does not fail as readily when insulted with water compared to known sanitary tissue products) and/or wet usage and/or better cleaning, such as soil removal and/or soil dislodging, than existing sanitary tissue products.

SUMMARY OF THE INVENTION

The present invention fulfills the need described above by providing a novel surface pattern on a sanitary tissue product's surface.
The solution to the problem described above is to make a surface pattern that comprises a set of lines of a plurality of variable-sized discrete depressions, for example dot depressions of varying sizes, with and/or without a geometric shape, such as a rhombus element, positioned between the set of lines, wherein the variable-sized discrete depressions are arranged in a periodic sequence based on the size of the discrete depressions such that the surface pattern that conveys better wet properties and/or wet usage and/or better cleaning, such as soil removal and/or soil dislodging, than known surface patterns on sanitary tissue products.
In one example of the present invention, a sanitary tissue product comprising a surface pattern having a repeating design element, wherein the repeating design element contains a first geometric shape, for example a first rhombus element, having a larger dimension and a smaller dimension such that it exhibits an aspect ratio of greater than 1.25, wherein the first geometric shape is positioned between a first set of two lines formed by a plurality of variable-sized discrete depressions, wherein the variable-sized discrete depressions are arranged in a periodic sequence based on the size of the discrete depressions, wherein the two lines are symmetrical to one another along the rhombus element's largest dimension, is provided.
In still another example of the present invention, a method for making a sanitary tissue product of the present invention, the method comprising the step of imparting, for example by embossing and/or molding, a surface pattern according to the present invention to a surface of a fibrous structure and/or sanitary tissue product, is provided.
Accordingly, the present invention provides a sanitary tissue product comprising a surface pattern according to the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic representation of a prior art surface pattern;

FIG. 2 is an image a sanitary tissue product comprising the prior art surface pattern of FIG. 1;

FIG. 3 is a schematic representation of an example of a repeating design element of a surface pattern according to the present invention;

FIG. 4 is a schematic representation of another example of a repeating design element of a surface pattern according to the present invention;

FIG. 5 is a schematic representation of another example of a repeating design element of a surface pattern according to the present invention;

FIG. 6 is a schematic representation of an example of a sanitary tissue product comprising a surface pattern according to the present invention;

FIG. 7 is a schematic representation of an example of a sanitary tissue product comprising a surface pattern according to the present invention;

FIG. 8 is a schematic representation of an example of a sanitary tissue product comprising a surface pattern according to the present invention; and

FIG. 9 is a schematic representation of an example of a sanitary tissue product comprising a surface pattern according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Definitions

“Sanitary tissue product” as used herein means a soft, low density (i.e. <about 0.15 g/cm³) sanitary tissue product useful as a wiping implement for post-urinary and post-bowel movement cleaning (toilet tissue), for otorhinolaryngological discharges (facial tissue), multi-functional absorbent and cleaning uses (absorbent towels also referred to as paper towels) and wet and dry wipes. The sanitary tissue product may be convolutedly wound upon itself about a core or without a core to form a sanitary tissue product roll. Alternatively, the sanitary tissue product may be in the form of discrete sheets.
The sanitary tissue products and/or fibrous structures of the present invention may exhibit a basis weight of greater than 15 g/m²(9.2 lbs/3000 ft²) to about 120 g/m²(73.8 lbs/3000 ft²) and/or from about 15 g/m²(9.2 lbs/3000 ft²) to about 110 g/m²(67.7 lbs/3000 ft²) and/or from about 20 g/m²(12.3 lbs/3000 ft²) to about 100 g/m²(61.5 lbs/3000 ft²) and/or from about 30 (18.5 lbs/3000 ft²) to 90 g/m²(55.4 lbs/3000 ft²). In addition, the sanitary tissue products and/or fibrous structures of the present invention may exhibit a basis weight between about 40 g/m²(24.6 lbs/3000 ft²) to about 120 g/m²(73.8 lbs/3000 ft²) and/or from about 50 g/m²(30.8 lbs/3000 ft²) to about 110 g/m²(67.7 lbs/3000 ft²) and/or from about 55 g/m²(33.8 lbs/3000 ft²) to about 105 g/m²(64.6 lbs/3000 ft²) and/or from about 60 (36.9 lbs/3000 ft²) to 100 g/m²(61.5 lbs/3000 ft²).
The sanitary tissue products of the present invention may exhibit a density of less than about 0.60 g/cm³and/or less than about 0.30 g/cm³and/or less than about 0.20 g/cm³and/or less than about 0.10 g/cm³and/or less than about 0.07 g/cm³and/or less than about 0.05 g/cm³and/or from about 0.01 g/cm³to about 0.20 g/cm³and/or from about 0.02 g/cm³to about 0.10 g/cm³.
The sanitary tissue products of the present invention may be in the form of sanitary tissue product rolls. Such sanitary tissue product rolls may comprise a plurality of connected, but perforated sheets of fibrous structure, that are separably dispensable from adjacent sheets.
The sanitary tissue products of the present invention may comprise additives such as softening agents such as silicones and quaternary ammonium compounds, temporary wet strength agents, permanent wet strength agents, bulk softening agents, lotions, silicones, wetting agents, latexes, especially surface-pattern-applied latexes, dry strength agents such as carboxymethylcellulose and starch, and other types of additives suitable for inclusion in and/or on sanitary tissue products.
“Fibrous structure” as used herein means a structure that comprises one or more filaments and/or fibers. In one example, a fibrous structure according to the present invention means an orderly arrangement of filaments and/or fibers within a structure in order to perform a function. Non-limiting examples of fibrous structures of the present invention include paper, fabrics (including woven, knitted, and non-woven), and absorbent pads (for example for diapers or feminine hygiene products).
Non-limiting examples of processes for making fibrous structures include known wet-laid papermaking processes and air-laid papermaking processes. Such processes typically include steps of preparing a fiber composition in the form of a suspension in a medium, either wet, more specifically aqueous medium, or dry, more specifically gaseous, i.e. with air as medium. The aqueous medium used for wet-laid processes is oftentimes referred to as a fiber slurry. The fibrous slurry is then used to deposit a plurality of fibers onto a forming wire or belt such that an embryonic fibrous structure is formed, after which drying and/or bonding the fibers together results in a fibrous structure. Further processing the fibrous structure may be carried out such that a finished fibrous structure is formed. For example, in typical papermaking processes, the finished fibrous structure is the fibrous structure that is wound on the reel at the end of papermaking, and may subsequently be converted into a finished product, e.g. a sanitary tissue product.
The fibrous structures of the present invention may be homogeneous or may be layered. If layered, the fibrous structures may comprise at least two and/or at least three and/or at least four and/or at least five layers.
The fibrous structures of the present invention may be co-formed fibrous structures.
“Co-formed fibrous structure” as used herein means that the fibrous structure comprises a mixture of at least two different materials wherein at least one of the materials comprises a filament, such as a polypropylene filament, and at least one other material, different from the first material, comprises a solid additive, such as a fiber and/or a particulate. In one example, a co-formed fibrous structure comprises solid additives, such as fibers, such as wood pulp fibers, and filaments, such as polypropylene filaments.
“Solid additive” as used herein means a fiber and/or a particulate.
“Particulate” as used herein means a granular substance or powder.
“Fiber” and/or “Filament” as used herein means an elongate particulate having an apparent length greatly exceeding its apparent width, i.e. a length to diameter ratio of at least about 10. In one example, a “fiber” is an elongate particulate as described above that exhibits a length of less than 5.08 cm (2 in.) and a “filament” is an elongate particulate as described above that exhibits a length of greater than or equal to 5.08 cm (2 in.).
Fibers are typically considered discontinuous in nature. Non-limiting examples of fibers include wood pulp fibers and synthetic staple fibers such as polyester fibers.
Filaments are typically considered continuous or substantially continuous in nature. Filaments are relatively longer than fibers. Non-limiting examples of filaments include meltblown and/or spunbond filaments. Non-limiting examples of materials that can be spun into filaments include natural polymers, such as starch, starch derivatives, cellulose and cellulose derivatives, hemicellulose, hemicellulose derivatives, and synthetic polymers including, but not limited to polyvinyl alcohol filaments and/or polyvinyl alcohol derivative filaments, and thermoplastic polymer filaments, such as polyesters, nylons, polyolefins such as polypropylene filaments, polyethylene filaments, and biodegradable or compostable thermoplastic fibers such as polylactic acid filaments, polyhydroxyalkanoate filaments and polycaprolactone filaments. The filaments may be monocomponent or multicomponent, such as bicomponent filaments.
In one example of the present invention, “fiber” refers to papermaking fibers. Papermaking fibers useful in the present invention include cellulosic fibers commonly known as wood pulp fibers. Applicable wood pulps include chemical pulps, such as Kraft, sulfite, and sulfate pulps, as well as mechanical pulps including, for example, groundwood, thermomechanical pulp and chemically modified thermomechanical pulp. Chemical pulps, however, may be preferred since they impart a superior tactile sense of softness to tissue sheets made therefrom. Pulps derived from both deciduous trees (hereinafter, also referred to as “hardwood”) and coniferous trees (hereinafter, also referred to as “softwood”) may be utilized. The hardwood and softwood fibers can be blended, or alternatively, can be deposited in layers to provide a stratified web. U.S. Pat. No. 4,300,981 and U.S. Pat. No. 3,994,771 are incorporated herein by reference for the purpose of disclosing layering of hardwood and softwood fibers. Also applicable to the present invention are fibers derived from recycled paper, which may contain any or all of the above categories as well as other non-fibrous materials such as fillers and adhesives used to facilitate the original papermaking. Non-limiting examples of suitable hardwood pulp fibers include eucalyptus and acacia. Non-limiting examples of suitable softwood pulp fibers include Southern Softwood Kraft (SSK) and Northern Softwood Kraft (NSK).
In addition to the various wood pulp fibers, other cellulosic fibers such as cotton linters, rayon, lyocell and bagasse can be used in this invention. Other sources of cellulose in the form of fibers or capable of being spun into fibers include grasses and grain sources.
In addition, trichomes, such as from “lamb's ear” plants, and seed hairs can also be utilized in the fibrous structures and/or sanitary tissue products of the present invention.
“Basis Weight” as used herein is the weight per unit area of a sample reported in lbs/3000 ft²or g/m²and is measured according to the Basis Weight Test Method described herein.
“Caliper” as used herein means the macroscopic thickness of a fibrous structure. Caliper is measured according to the Caliper Test Method described herein.
“Density” as used herein is calculated as the quotient of the Basis Weight expressed in grams per square meter divided by the Caliper expressed in microns.
“Machine Direction” or “MD” as used herein means the direction parallel to the flow of the fibrous structure through the fibrous structure making machine and/or sanitary tissue product manufacturing equipment.
“Cross Machine Direction” or “CD” as used herein means the direction parallel to the width of the fibrous structure making machine and/or sanitary tissue product manufacturing equipment and perpendicular to the machine direction.
“Ply” as used herein means an individual, integral fibrous structure.
“Plies” as used herein means two or more individual, integral fibrous structures disposed in a substantially contiguous, face-to-face relationship with one another, forming a multi-ply sanitary tissue product. It is also contemplated that an individual, integral fibrous structure can effectively form a multi-ply sanitary tissue product, for example, by being folded on itself.
“Textured surface pattern” with respect to a sanitary tissue product in accordance with the present invention means herein a pattern of protrusions and/or depressions that is present on at least one surface of the sanitary tissue product. For example, the surface pattern may comprise embossments.
“Embossed” as used herein with respect to a sanitary tissue product means a sanitary tissue product that has been subjected to a process which converts a smooth surfaced fibrous structure to a decorative surface by replicating a design on one or more emboss rolls, which form a nip through which the fibrous structure passes. Embossed does not include creping, microcreping, printing or other processes that may impart a texture and/or decorative pattern to a fibrous structure.
“Line depression” as used herein means a depression in the surface of a sanitary tissue product that comprises a continuous line that has an aspect ratio of greater than 1.5:1 and/or greater than 1.75:1 and/or greater than 2:1 and/or greater than 5:1. In one example, the line depression exhibits a length of at least 2 mm and/or at least 4 mm and/or at least 6 mm and/or at least 1 cm to about 10.16 cm and/or to about 8 cm and/or to about 6 cm and/or to about 4 cm.
The line depressions of the present invention may be formed by line embossing and/or wet forming, such as by wet molding and/or by using a through-air-drying fabric and/or by using an imprinted through-air-drying fabric and/or by using a belt comprising a patterned resin.
In one example, the line depression is a discrete element. In another example, the line depression defines the perimeter of a shape, such as a circle, ellipse, rectangle, or other rhombuses and/or triangles.
“Dot depression” as used herein means a depression that exhibits an aspect ratio of about 1:1. Non-limiting examples of dot depressions are depressions that are shaped like circles, squares, ellipses, rectangles (dashes) and/or other rhombuses and/or triangles.
“Water-resistant” as it refers to a surface pattern or part thereof means that a pattern retains its structure and/or integrity after being saturated by water and the pattern is still visible to a consumer. In one example, the depressions may be water-resistant.

Surface Patterns

FIG. 3 shows an example of a repeating design element 24 of a surface pattern 12 of the present invention that can be imparted to a surface 14 fibrous structures and/or sanitary tissue products comprising such fibrous structures of the present invention. The surface pattern 12 comprises a repeating design element 24. The repeating design element 24 comprises a first set of lines 26 formed by a plurality of variable-sized discrete depressions 28. The variable-sized discrete depressions 28 are shown as dot depressions, but any suitable geometric shapes, such as dashes, triangles, ellipses, stars, and the like, may be used. The variable-sized discrete depressions 28 are arranged in a periodic sequence along the length of one of the lines 26 based on the size of the discrete depressions 28. Periodic sequence as used herein means that a line 26 of variable-sized discrete depressions 28 is formed by line segments that contain an arrangement of variable-sized discrete depressions 28 that are sequential within one line segment, for example as follows:
Extra Large—Large—Medium—Small—Extra Small—Small—Medium—Large—Extra Large

Example 1

Extra Small—Small—Medium—Large—Extra Large—Large—Medium—Small—Extra Small

Example 2

Large—Medium—Small—Medium—Large—Medium—Small—Medium—Large

Example 3

For a given size of discrete depression, for example Extra Large in Example 2 above, one or more discrete depressions 28 may be present in that position.
In one example, a line 26 of variable-sized discrete depressions 28 may comprise one or more inflection points 30 along the length of the line 26 and/or line set where the direction of the line 26 changes. The inflection point 30 may actually be a discrete depression 28 and/or a plurality of discrete depressions 28 and/or even a space between two adjacent discrete depressions 28. In Example 3 above, the inflection points may be at the small discrete depressions, for example at a minimum-sized discrete depression within the line. In another example, the inflection point may be at the largest discrete depression, for example the maximum-sized discrete depression within the line.
As shown in FIG. 3, the two lines 26 of the first set may be asymptotic to one another. In another example, the two lines 26 may be symmetrical to one another. In one case, the two lines 26 of the first set are mirror images of one another including the sizes and arrangements of their discrete depressions 28.
In one example, a geometric shape 32, such as a rhombus element, may be positioned between the two lines 26 of the first set. The two lines 26 of the first set may be oriented and/or arranged such that a node 20 is formed (by the combination of) between the two lines 26 of the first set. The geometric shape 32 may be positioned within the node 20.
The geometric shape 32 comprises a largest dimension A and a smallest dimension B such that the geometric shape 32 exhibits an aspect ratio of greater than 1.25 and/or greater than 1.3 and/or greater than 1.4 and/or greater than 1.5 and/or less than 3 and/or less than 2.5 and/or less than 2 and/or less than 1.9. In one example, the aspect ratio is from about 1.6 to about 1.8 and/or from about 1.7 to about 1.8. The two lines 26 of the first set may be symmetrical along the geometric shape's largest dimension A. The geometric shape 32 may comprise line embossments and/or line moldings.
The two lines 26 of the first set may be curvilinear, such as sinusoidal.
As shown in FIG. 4, the node 20 may comprise a two or more geometric shapes 32, such as a double rhombus element, for example an inner rhombus element. In one example, the aspect ratios of the two or more geometric shapes 32 are similar, for example both greater than 1.25 and/or greater than 1.3 and/or greater than 1.4 and/or greater than 1.5 and/or less than 3 and/or less than 2.5 and/or less than 2 and/or less than 1.9. Further, the largest dimensions of the two or more geometric shapes 32 may be along the same axis.
In one example, the rhombus element comprises an inner rhombus element having a larger dimension and smaller dimension that are different from the rhombus element's larger and smaller dimensions. In another example, the inner rhombus element exhibits a larger dimension and smaller dimension such that the inner rhombus element exhibits an aspect ratio of greater than 1.25. In even another example, the inner rhombus element's larger dimension is parallel to the rhombus element's larger dimension.
As shown in FIG. 5, in another example of the repeating design element 24, the repeating design element comprises a first set of lines 26 and a second set of lines 34. The second set of lines 34, like the first set of lines 26, may be formed by a plurality of variable-sized discrete depressions 28, in one example, embossments, with all the same characteristics and arrangements (i.e., periodic sequence) as were described above for the discrete depressions 28 of the lines 26 of the first set. In one example, the periodic sequence of the plurality of variable-sized discrete depressions 28 of the second set of lines 34 is different from the periodic sequence of the plurality of variable-sized discrete depressions 28 of the first set of lines 26. In one example, this difference in periodic sequence positions the smallest (minimum-sized discrete depression 28A of a line 26 of the first set in the same corresponding position within its line as the maximum-sized discrete depression 28B of a line 34 of the second set.
The lines 34 of the second set may be asymptotic to one another. Further, the lines 34 of the second set are spaced apart, for example substantially equally distanced from one another, from the lines 26 of the first set along the length of the lines 26, 34. The lines 34 of the second set may be symmetrical to one another, for example along the geometric shape's largest dimension A. In one case, the two lines 34 of the second set are minor images of one another including the sizes and arrangements of their discrete depressions 28.
In one example, a first set of lines are equally distanced from the rhombus element's vertices in the rhombus element's smaller dimension.
The second set of lines 34 may form a node 36 that contains the node 20 of the first set of lines 26.
The lines 34 of the second set may be curvilinear, such as sinusoidal.
In one example, the node 20 may comprise a text, such as a trademark, for example “Bounty” instead of a geometric shape 32.
In one example, the lines 26 of the first set and the lines 34 of the second set are substantially parallel to the cross machine direction of the fibrous structure and/or sanitary tissue product.
In addition to the first and second set of lines 26, 34, the repeating design element 24 of the surface pattern 12 may comprise one or more additional sets of lines (not shown), which may be formed from a plurality of discrete depressions, for example like the first and second set of lines.

Sanitary Tissue Products

As shown in FIGS. 6-9, examples of sanitary tissue products 10 of the present invention, such as paper towels, comprising a surface pattern 12 according to the present invention.
The surface pattern 12 may be an emboss pattern, imparted by passing a fibrous structure and/or sanitary tissue product made from a fibrous structure through an embossing nip comprising at least one patterned embossing roll patterned to impart a surface pattern according to the present invention, and/or a water-resistant pattern (i.e., wet-molded pattern), such as a patterned through-air-drying belt that is patterned to impart a surface pattern according to the present invention, typically imparted during the fibrous structure-making process.
In one example, the surface pattern 12 of the sanitary tissue product 10 aids in the removal and/or dislodging soil more effectively than known sanitary tissue products and/or the perception of removal and/or dislodging of soil more effectively than known sanitary tissue products.
The sanitary tissue products comprising a surface pattern of the present invention may be perceived by consumers of sanitary tissue products as being able to provide better cleaning of soil compared to sanitary tissue products comprising surface patterns not within the scope of the present invention.

Methods for Making Sanitary Tissue Products

The sanitary tissue products, for example paper towel products, of the present invention may be made by any suitable process known in the art so long as a surface pattern according to the present invention is imparted to a surface of the sanitary tissue products. The method may be a sanitary tissue product making process that uses a cylindrical dryer such as a Yankee (a Yankee-process) or it may be a Yankeeless process as is used to make substantially uniform density (not differential density) and/or uncreped sanitary tissue products.
The sanitary tissue products of the present invention may be made using a molding member. A “molding member” is a structural element that can be used as a support for an embryonic web comprising a plurality of cellulosic fibers and a plurality of synthetic fibers, as well as a forming unit to form, or “mold,” a desired microscopical geometry of the sanitary tissue product of the present invention. The molding member may comprise any element that has fluid-permeable areas and the ability to impart a microscopical three-dimensional pattern to the structure being produced thereon, and includes, without limitation, single-layer and multi-layer structures comprising a stationary plate, a belt, a woven fabric (including Jacquard-type and the like woven patterns), a band, and a roll. In one example, the molding member is a deflection member. The molding member may comprise a surface pattern according to the present invention that is imparted to the sanitary tissue product during the sanitary tissue product making process.
A “reinforcing element” is a desirable (but not necessary) element in some embodiments of the molding member, serving primarily to provide or facilitate integrity, stability, and durability of the molding member comprising, for example, a resinous material. The reinforcing element can be fluid-permeable or partially fluid-permeable, may have a variety of embodiments and weave patterns, and may comprise a variety of materials, such as, for example, a plurality of interwoven yarns (including Jacquard-type and the like woven patterns), a felt, a plastic, other suitable synthetic material, or any combination thereof.
In one example of a method for making a sanitary tissue product of the present invention, the method comprises the step of contacting an embryonic fibrous web with a deflection member (molding member) such that at least one portion of the embryonic fibrous web is deflected out-of-plane of another portion of the embryonic fibrous web. The phrase “out-of-plane” as used herein means that the sanitary tissue product comprises a protuberance, such as a dome and/or line, or a cavity that extends away from the plane of the sanitary tissue product. The molding member may comprise a through-air-drying belt, which comprises a resinous framework that imparts the surface pattern of the present invention to a surface of the sanitary tissue product and/or one or more fibrous structure making up the sanitary tissue product.
In another example the sanitary tissue product and/or fibrous structure used to make the sanitary tissue product may be subjected to an embossing operation that embosses the surface pattern of the present invention on a surface of the sanitary tissue product, for example paper towel, and/or fibrous structure. The embossing process creates out-of-plane deformation such that protuberances, such as a domes and/or lines, or corresponding cavities (based on what surface is viewed) that extend away from the plane of the sanitary tissue product and/or fibrous structure.
In another example of a method for making a sanitary tissue product of the present invention, the method comprises the steps of:

- (a) providing a fibrous furnish comprising fibers, for example pulp fibers, such as wood pulp fibers;
- (b) depositing the fibrous furnish onto a foraminous member to form an embryonic fibrous web;
- (c) associating the embryonic fibrous web with a molding member comprising a surface pattern such that the surface pattern;
- (d) drying said embryonic fibrous web such that that the surface pattern is imparted to the dried fibrous structure to form a molded fibrous structure; and
- (e) forming a sanitary tissue product from the molded fibrous structure.

In another example of a method for making a sanitary tissue product of the present invention, the method comprises the steps of:

- (a) providing a fibrous furnish comprising fibers, for example pulp fibers, such as wood pulp fibers;
- (b) depositing the fibrous furnish onto a foraminous member to form an embryonic fibrous web; and
- (c) drying said embryonic fibrous web such that that a dried fibrous structure formed;
- (d) subjecting the dried fibrous structure to an embossing operation such that a surface pattern according to the present invention is imparted to a surface of the dried fibrous structure to form an embossed fibrous structure; and
- (e) forming a sanitary tissue product from the embossed fibrous structure.

- (a) providing a fibrous structure; and
- (b) imparting a surface pattern to the fibrous structure to produce the sanitary tissue product.

In another example, the step of imparting a surface pattern to a sanitary tissue product and/or fibrous structure comprises contacting a molding member comprising a surface pattern according to the present invention with a sanitary tissue product and/or fibrous structure such that the surface pattern is imparted to the sanitary tissue product and/or fibrous structure. The molding member may be a patterned through-air-drying belt that comprises a surface pattern.
In another example, the step of imparting a surface pattern to a sanitary tissue product and/or fibrous structure comprises passing a sanitary tissue product and/or fibrous structure through an embossing nip formed by at least one embossing roll comprising a surface pattern according to the present invention such that the surface pattern is imparted to the sanitary tissue product and/or fibrous structure.

NON-LIMITING EXAMPLES

Example 1

Examples of articles of manufacture, specifically fibrous structures; namely, paper towels for use in the comparative and inventive examples below are produced utilizing a cellulosic pulp fiber furnish consisting of about 55% refined softwood furnish consisting of about 44% Northern Bleached Softwood Kraft (Bowater), 44% Northern Bleached Softwood Kraft (Celgar) and 12% Southern Bleached Softwood Kraft (Alabama River Softwood, Weyerhaeuser); about 30% of unrefined hardwood Eucalyptus Bleached Kraft consisting of about 80% (Fibria) and 20% NBHK (Aspen) (Peace River); and about 15% of an unrefined furnish consisting of a blend of about 27% Northern Bleached Softwood Kraft (Bowater), 27% Northern Bleached Softwood Kraft (Celgar), 42% Eucalyptus Bleached Kraft (Fibria) and 7% Southern Bleached Kraft (Alabama River Softwood, Weyerhaeuser). The 55% refined softwood is refined as needed to maintain target wet burst at the reel. Any furnish preparation and refining methodology common to the papermaking industry can be utilized.
A 3% active solution Kymene 5221 is added to the refined softwood line prior to an in-line static mixer and 1% active solution of Wickit 1285, an ethoxylated fatty alcohol available from Ashland Inc. is added to the unrefined Eucalyptus Bleached Kraft (Fibria) hardwood furnish. The addition levels are 21 and 1 lbs active/ton of paper, respectively.
The refined softwood and unrefined hardwood and unrefined NBSK/SSK/Eucalyptus bleached kraft/NDHK thick stocks are then blended into a single thick stock line followed by addition of 1% active carboxymethylcellulose (CMC-Finnfix) solution at 7 lbs active/ton of paper towel, and optionally, a softening agent may be added.
The thick stock is then diluted with white water at the inlet of a fan pump to a consistency of about 0.15% based on total weight of softwood, hardwood and simulated broke fiber. The diluted fiber slurry is directed to a non layered configuration headbox such that the wet web formed onto a Fourdrinier wire (foraminous wire). Optionally, a fines retention/drainage aid may be added to the outlet of the fan pump.
Dewatering occurs through the Fourdrinier wire and is assisted by deflector and vacuum boxes. The Fourdrinier wire is of a 5-shed, satin weave configuration having 87 machine-direction and 76 cross-direction monofilaments per inch, respectively. The speed of the Fourdrinier wire is about 750 fpm (feet per minute).
The embryonic wet web is transferred from the Fourdrinier wire at a fiber consistency of about 24% at the point of transfer, to a belt, such as a patterned belt through-air-drying resin carrying fabric. In the present case, the speed of the patterned through-air-drying fabric is approximately the same as the speed of the Fourdrinier wire. In another case, the embryonic wet web may be transferred to a patterned belt and/or fabric that is traveling slower, for example about 20% slower than the speed of the Fourdrinier wire (for example a wet molding process).
Further de-watering is accomplished by vacuum assisted drainage until the web has a fiber consistency of about 30%.
While remaining in contact with the patterned belt, the web is pre-dried by air blow-through pre-dryers to a fiber consistency of about 65% by weight.
After the pre-dryers, the semi-dry web is transferred to a Yankee dryer and adhered to the surface of the Yankee dryer with a sprayed creping adhesive. The creping adhesive is an aqueous dispersion with the actives consisting of about 75% polyvinyl alcohol, and about 25% CREPETROL® R6390. Optionally a crepe aid consisting of CREPETROL® A3025 may be applied. CREPETROL® R6390 and CREPETROL® A3025 are commercially available from Ashland Inc. (formerly Hercules Inc.). The creping adhesive diluted to about 0.15% adhesive solids and delivered to the Yankee surface at a rate of about 2# adhesive solids based on the dry weight of the web. The fiber consistency is increased to about 97% before the web is dry creped from the Yankee with a doctor blade.
In the present case, the doctor blade has a bevel angle of about 45° and is positioned with respect to the Yankee dryer to provide an impact angle of about 101° and the reel is run at a speed that is about 15% faster than the speed of the Yankee. In another case, the doctor blade may have a bevel angle of about 25° and be positioned with respect to the Yankee dryer to provide an impact angle of about 81° and the reel is run at a speed that is about 10% slower than the speed of the Yankee. The Yankee dryer is operated at a temperature of about 177° C. and a speed of about 800 fpm. The fibrous structure is wound in a roll using a surface driven reel drum having a surface speed of about 656 feet per minute.
One parent roll of the fibrous structure may be unwound and embossed with a surface texture as shown in FIGS. 3 to 9 and combined with another parent roll of the fibrous structure not embossed to form a two-ply paper towel product having a basis weight of about 45 to 54 g/m².

Test Methods

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 73° F.±4° F. (about 23° C.±2.2° C.) and a relative humidity of 50%±10% for 2 hours prior to the test. All plastic and paper board packaging materials must be carefully removed from the paper samples prior to testing. Discard any damaged product. All tests are conducted in such conditioned room.

Basis Weight Test Method

Basis weight of a sanitary tissue product sample is measured by selecting twelve (12) usable units (also referred to as sheets) of the sanitary tissue product and making two stacks of six (6) usable units each. Perforation must be aligned on the same side when stacking the usable units. A precision cutter is used to cut each stack into exactly 8.89 cm×8.89 cm (3.5 in.×3.5 in.) 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 g. 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 Basis Weight is calculated as follows:
$\underset{(lbs / 3000 {ft}^{2})}{Basis Weight} = \frac{Weight of basis weight pad (g) \times 3000 {ft}^{2}}{\begin{matrix} 453.6 g / lbs \times 12 (usable units) \times \\ [12.25 {in}^{2} (Area of basis weight pad) / 144 {in}^{2}] \end{matrix}}$ $\underset{(g / m^{2})}{Basis Weight} = \frac{Weight of basis weight pad (g) \times 10, 000 {cm}^{2} / m^{2}}{79.0321 {cm}^{2} (Area of basis weight pad) \times 12 (usable units)}$

Caliper Test Method

Caliper of a sanitary tissue product is measured by cutting five (5) samples of sanitary tissue product such that each cut sample is larger in size than a load foot loading surface of a VIR Electronic Thickness Tester Model II available from Thwing-Albert Instrument Company, Philadelphia, Pa. Typically, the load foot loading surface has a circular surface area of about 3.14 in². The sample is confined between a horizontal flat surface and the load foot loading surface. The load foot loading surface applies a confining pressure to the sample of 15.5 g/cm². The caliper of each sample is the resulting gap between the flat surface and the load foot loading surface. The caliper is calculated as the average caliper of the five samples. The result is reported in millimeters (mm).
The dimensions and values disclosed herein are not to be understood as being strictly limited to the exact numerical values recited. Instead, unless otherwise specified, each such dimension is intended to mean both the recited value and a functionally equivalent range surrounding that value. For example, a dimension disclosed as “40 mm” is intended to mean “about 40 mm.”
Every document cited herein, including any cross referenced or related patent or application and any patent application or patent to which this application claims priority or benefit thereof, is hereby incorporated herein by reference in its entirety unless expressly excluded or otherwise limited. The citation of any document is not an admission that it is prior art with respect to any invention disclosed or claimed herein or that it alone, or in any combination with any other reference or references, teaches, suggests or discloses any such invention. Further, to the extent that any meaning or definition of a term in this document conflicts with any meaning or definition of the same term in a document incorporated by reference, the meaning or definition assigned to that term in this document shall govern.
While particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.

Claims

What is claimed is:

1. A sanitary tissue product comprising a surface pattern having a repeating design element, wherein the repeating design element contains a first rhombus element having larger dimension and smaller dimension such that it exhibits an aspect ratio of greater than 1.25, wherein the first rhombus element is positioned between a first set of two lines formed by a plurality of variable-sized discrete depressions, wherein the variable-sized discrete depressions are arranged in a periodic sequence based on size of the discrete depressions, wherein the two lines are symmetrical to one another along the rhombus element's largest dimension.

2. The sanitary tissue product according to claim 1 wherein the two lines of the first set are curvilinear such that the combination of the two lines of the first set forms a first node within which the rhombus element is positioned.

3. The sanitary tissue product according to claim 1 wherein at least one line of the first set comprises one or more inflection points along the length of the line of the first set.

4. The sanitary tissue product according to claim 3 wherein at least one of the inflection points comprises a minimum-sized discrete depression within the at least one line of the first set.

5. The sanitary tissue product according to claim 3 wherein at least one of the inflection points comprises a maximum-sized discrete depression within the at least one line of the first set.

6. The sanitary tissue product according to claim 1 wherein the two lines of the first set are asymptotic to one another.

7. The sanitary tissue product according to claim 1 wherein the repeating design element further comprises a second set of two lines formed by a plurality of variable-sized discrete depressions, wherein the variable-sized discrete depressions are arranged in a periodic sequence based on size of the discrete depressions, wherein the two lines of the second set are symmetrical to one another along the rhombus element's largest dimension.

8. The sanitary tissue product according to claim 7 wherein the two lines of the second set are curvilinear such that the combination of the two lines of the second set forms a second node within which the first node formed by the combination of the two lines of the first set is positioned.

9. The sanitary tissue product according to claim 7 wherein at least one line of the second set comprises one or more inflection points along the length of the line of the second set.

10. The sanitary tissue product according to claim 7 wherein the two lines of the second set of two lines are asymptotic to one another.

11. The sanitary tissue product according to claim 7 wherein the lines of the first set of two lines exhibit a periodic sequence that is different from the lines of the second set of two lines.

12. The sanitary tissue product according to claim 7 wherein the first and second set of lines are equally distanced from one another.

13. The sanitary tissue product according to claim 7 wherein at least one line of the first set comprises at least one inflection point comprising a minimum-sized discrete depression and at least one line of the second set comprises at least one inflection point comprising a maximum-sized discrete depression, wherein the minimum-sized discrete depression of the line of the first set is at a corresponding position within its line as is the maximum-sized discrete depression of the line of the second set.

14. The sanitary tissue product according to claim 1 wherein the first set of lines are equally distanced from the rhombus element's vertices in the rhombus element's smaller dimension.

15. The sanitary tissue product according to claim 1 wherein the rhombus element comprises an inner rhombus element having a larger dimension and smaller dimension that are different from the rhombus element's larger and smaller dimensions.

16. The sanitary tissue product according to claim 15 wherein the inner rhombus element exhibits a larger dimension and smaller dimension such that the inner rhombus element exhibits an aspect ratio of greater than 1.25.

17. The sanitary tissue product according to claim 15 wherein the inner rhombus element's larger dimension is parallel to the rhombus element's larger dimension.

18. The sanitary tissue product according to claim 1 wherein the discrete depressions are embossments.

19. The sanitary tissue product according to claim 1 wherein the discrete depressions are wet formed.

20. The sanitary tissue product according to claim 1 wherein the sanitary tissue product is a paper towel.