CELL ARRANGEMENTS AND BELTS FOR PRODUCING

Description

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional Application No. 63/711,953, filed Oct. 25, 2024, the substance of which is incorporated herein by reference.

FIELD

The present disclosure generally relates to fibrous structures comprising discrete elements situated in patterns, and more specifically to fibrous structures comprising discrete elements situated in patterns that provide support to pillow regions. The present disclosure also generally relates to papermaking belts that are used in creating such fibrous structures and masks used to create structuring layers on such papermaking belts.

BACKGROUND

Fibrous structures, such as sanitary tissue products, are useful in everyday life in various ways. These products may be used as wiping implements for post-urinary and post-bowel movement cleaning (toilet tissue and wet wipes), for otorhinolaryngological discharges (facial tissue), and multi-functional absorbent and cleaning uses (paper towels). Retail consumers of such fibrous structures look for products with certain performance properties, for example softness, smoothness, strength, and absorbency. For fibrous structures provided in roll form (e.g., toilet tissue and paper towels), retail consumers also look for products with roll properties that indicate value and quality, such as higher roll bulk, greater roll firmness, and lower roll compressibility. However, many times the independent goals of superior product performance (e.g., performance properties and/or roll properties) are in contradiction to one another. Moreover, consumers limit the tasks they use fibrous tissue products for based on product feel, but often those products with high softness do not have superior strength or absorbency. For instance, the smoothness of a paper towel may depend on the wet-laid structure provided by the papermaking belt utilized during paper production and/or the emboss pattern applied during the paper converting process. But such papermaking-belt-provided structure and/or emboss may also be predominantly responsible for its strength and absorbent characteristics. Furthermore, the papermaking-belt-provided structure and/or emboss may be predominantly responsible for driving roll bulk, roll firmness, and lower roll compressibility. Accordingly, manufacturers continually seek to make new fibrous structures with a combination of good performance and desired roll properties through selection of material components, as well as selection of equipment and processes used in manufacturing the fibrous structures. Various knuckle and pillow patterns have been disclosed and marketed to achieve these desired properties. Applicants, however, have discovered knuckle and pillow patterns that create improved properties by using discrete knuckle (or discrete pillow) structures that distill key roll properties via strategic supporting structures while driving premium function. These inventive cell perimeters, knuckles, pillows, cell clusters, and cell patterns result in fibrous structures that have desired and improved properties. Cell clusters designed to support a central area may provide benefits to substrate compressive properties by reinforcing those areas prone to collapse. Substrate compressive properties may also be influenced by the arrangement of the clusters relative to one another and relative to any surrounding channels. These re-enforcing clusters and arrangements can drive improvement in compressive properties while maintaining or improving other parameters within the pattern that drive superior performance (e.g. softness, strength, and absorbency).

The discussion of shortcomings and needs existing in the field prior to the present disclosure is in no way an admission that such shortcomings and needs were recognized by those skilled in the art prior to the present disclosure.

SUMMARY

Various embodiments solve the above-mentioned problems and provide fibrous substrates that have desired aesthetics and properties, as well as methods and devices useful for producing such fibrous substrates themselves.

Various embodiments relate to a structure, such as a fibrous structure, a papermaking belt, a structuring layer, and a mask. The structure may comprise a plurality of cell clusters. At least some of the plurality of cell clusters may define a first para-cluster channel therebetween. At least a pair of the plurality of cell clusters may define a wedge-shaped cross channel therebetween. The wedge-shaped cross channel may comprise a narrow portion and a wide portion and the narrow portion of the wedge-shaped support may be supportively-adjacent to the first para-cluster channel.

Various embodiments relate to a structure, such as a fibrous structure, a papermaking belt, a structuring layer, and a mask. The structure may comprise a plurality of cell clusters. At least some of the plurality of cell clusters may define a first para-cluster channel therebetween. The first para-cluster channel may have a first side and a second side. A first cell cluster on the first side of the first para-cluster channel may comprise a first intra-cluster channel that is substantially perpendicular to and supportively-adjacent to a portion of the first para-cluster channel. A second cell cluster on the second side of the first para-cluster channel may comprise a second intra-cluster channel that is substantially perpendicular to and supportively-adjacent to the portion of the first para-cluster channel. The first intra-cluster channel and the second intra-cluster channel may be aligned or not aligned. Additionally or alternatively, the cells of the first cell cluster may be aligned or not aligned with the cells of the second cell cluster.

Various embodiments relate to a structure, such as a fibrous structure, a papermaking belt, a structuring layer, and a mask. The structure may comprise at least one cell cluster. The cell cluster may comprise a plurality of cells, each cell comprises a non-center-facing side and a center-facing side. The center-facing side of each cell in each cell cluster may face a centroid of the cell cluster. The non-center-facing side of each cell in each cell cluster may define a portion of a perimeter of the cell cluster. The at least one cell may exhibit a concavity ratio of about 0.8 to 1. The center-facing sides of the cells in each cell cluster may bound a supported area having an area of from greater than about 1.9 mm² to about 10 mm².

These and other features, aspects, and advantages of various embodiments will become better understood with reference to the following description, figures, and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The above-mentioned and other features and advantages of this disclosure, and the manner of attaining them, will become more apparent and the disclosure itself will be better understood by reference to the following description of non-limiting examples of the disclosure taken in conjunction with the accompanying drawings.

FIG. 1 is a representative papermaking belt of the kind useful to make the fibrous structures of the present disclosure.

FIG. 2 is a photograph of a portion of a paper towel product previously marketed by The Procter & Gamble Co.

FIG. 3 is a plan view of a portion of a mask pattern used to make the papermaking belt that may produce a paper towel like the one shown in FIG. 2.

FIG. 4 is a top view of a mask that may be used to produce a structuring layer on a papermaking belt like the one shown in FIG. 5.

FIG. 5 is an isometric view of a structuring layer on a papermaking belt that includes a plurality of conceptual cells in the form of knuckle-forming elements as well as pillow-forming regions therebetween.

FIG. 6 is an isometric view of a fibrous structure that may be produced with the papermaking belt shown in FIG. 5, the fibrous structure comprising conceptual cells in the form of higher-density knuckles as well as lower-density pillows therebetween.

FIG. 7 is a plan view of a conceptual cell.

FIG. 8 is a plan view of a cell cluster comprising a plurality of conceptual cells and showing orientations thereof.

FIG. 9 is a plan view of a cell cluster showing a radius about a centroid of the cluster within which all center-facing sides of the cluster must be positioned.

FIG. 10 is a plan view of a cell cluster comprising a plurality of conceptual cells surrounding a supported central area.

FIG. 11 is a plan view of a cell cluster comprising a plurality of conceptual cells and showing intra-cluster channels extending between the conceptual cells.

FIG. 12 is a plan view of a cell cluster having a supported central area having a circular shape and showing intra-cluster channels extending between the conceptual cells.

FIG. 13 is a plan view of a cell cluster having a supported central area having an octagonal shape and showing intra-cluster channels extending between the conceptual cells.

FIG. 14 is a plan view of a cell cluster having a supported central area having a circular shape and showing intra-cluster channels extending between the conceptual cells.

FIG. 15 is a plan view of a cell cluster having a supported central area having an octagonal shape and showing intra-cluster channels extending between the conceptual cells.

FIG. 16 is a plan view of a cell cluster having a supported central area having a square shape with corner radiuses and showing intra-cluster channels extending between the conceptual cells.

FIG. 17 is a plan view of a cell cluster having a supported central area having a square shape with corner radiuses and showing intra-cluster channels extending between the conceptual cells.

FIG. 18 is a plan view of a cell cluster having a supported central area having a square shape with corner radiuses and showing intra-cluster channels extending between the conceptual cells.

FIG. 19 is a plan view of a cell cluster having a supported central area having a square shape with corner radiuses and showing intra-cluster channels extending between the conceptual cells.

FIG. 20 is a plan view of a cell cluster having a supported central area having a hexagonal shape and showing intra-cluster channels extending between the conceptual cells.

FIG. 21 is a plan view of a cell cluster having a supported central area having a circular shape and showing intra-cluster channels extending between the conceptual cells.

FIG. 22 is a plan view of a cell cluster having a supported central area having a hexagonal shape and showing intra-cluster channels extending between the conceptual cells.

FIG. 23 is a plan view of a cell cluster having a supported central area having a circular shape and showing intra-cluster channels extending between the conceptual cells.

FIG. 24 is a plan view of a cell cluster having a supported central area having an oval shape and showing intra-cluster channels extending between the conceptual cells.

FIG. 25 is a plan view of a cell cluster having a supported central area having an oval shape and showing intra-cluster channels extending between the conceptual cells.

FIG. 26 is a plan view of a cell cluster having a supported central area having an oval shape and showing intra-cluster channels extending between the conceptual cells.

FIG. 27 is a plan view of a cell cluster having a supported central area having an oval shape and showing intra-cluster channels extending between the conceptual cells.

FIG. 28 is a plan view of a cell cluster having a supported central area having a circular shape and showing intra-cluster channels extending between the conceptual cells.

FIG. 29 is a plan view of a cell cluster having a supported central area having a circular shape and showing intra-cluster channels extending between the conceptual cells.

FIG. 30 is a plan view of a cell cluster having a supported central area having a circular shape and showing intra-cluster channels extending between the conceptual cells.

FIG. 31 is a plan view of a cell cluster having a supported central area having a circular shape and showing intra-cluster channels extending between the conceptual cells.

FIG. 32 is a plan view of a cell cluster having a supported central area having a circular shape and showing intra-cluster channels extending between the conceptual cells.

FIG. 33 is a plan view of a cell cluster having a supported central area having a circular shape and showing intra-cluster channels extending between the conceptual cells.

FIG. 34 is a plan view of a cell cluster with an outer perimeter having a square shape with radiused corners.

FIG. 35 is a plan view of a cell cluster with an outer perimeter having a square shape.

FIG. 36 is a plan view of a cell cluster with an outer perimeter having a hexagonal shape.

FIG. 37 is a plan view of a cell cluster with an outer perimeter having a circular shape.

FIG. 38 is a plan view of a channel-forming arrangement of cell clusters with an inter-cluster channel and a cross channel extending therebetween.

FIG. 39 is a plan view of a channel-forming arrangement of cell clusters with inter-cluster channels, a para-cluster channel, and cross channels extending therebetween.

FIG. 40 is a plan view of a channel-forming arrangement of cell clusters with a para-cluster channel extending therebetween, each cell cluster defining an intra-cluster channel supportively-adjacent to the para-cluster channel.

FIG. 41 is a plan view of a channel-forming arrangement of cell clusters with a para-cluster channel extending therebetween, each cell cluster defining an intra-cluster channel supportively-adjacent to the para-cluster channel, the cell clusters also defining cross channels supportively-adjacent to the para-cluster channel.

FIG. 42 is a plan view of a channel-forming arrangement of cell clusters with para-cluster channels extending therebetween and illustrating the width and spacing of the para-cluster channels.

FIG. 43 is a plan view of a pattern of cells.

FIG. 44 is a plan view of a cell cluster.

FIG. 45 is a plan view of a cell cluster.

FIG. 46 is Table 1 as discussed in the Examples.

FIG. 47 is Table 2 as discussed in the Examples.

It should be understood that the various embodiments are not limited to the examples illustrated in the figures.

DETAILED DESCRIPTION

Introduction and Definitions

This disclosure is written to describe the invention to a person having ordinary skill in the art, who will understand that this disclosure is not limited to the specific examples or embodiments described. The examples and embodiments are single instances of the invention which will make a much larger scope apparent to the person having ordinary skill in the art. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by the person having ordinary skill in the art. It is also to be understood that the terminology used herein is for the purpose of describing examples and embodiments only, and is not intended to be limiting, since the scope of the present disclosure will be limited only by the appended claims.

All the features disclosed in this specification (including any accompanying claims, abstract, and drawings) may be replaced by alternative features serving the same, equivalent, or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features. The examples and embodiments described herein are for illustrative purposes only and that various modifications or changes in light thereof will be suggested to the person having ordinary skill in the art and are to be included within the spirit and purview of this application. Many variations and modifications may be made to the embodiments of the disclosure without departing substantially from the spirit and principles of the disclosure. All such modifications and variations are intended to be included herein within the scope of this disclosure. For example, unless otherwise indicated, the present disclosure is not limited to particular materials, reagents, reaction materials, manufacturing processes, or the like, as such may vary. It is also to be understood that the terminology used herein is for purposes of describing particular embodiments only and is not intended to be limiting. It is also possible in the present disclosure that steps may be executed in different sequence where this is logically possible.

All numeric values are herein assumed to be modified by the term “about,” whether or not explicitly indicated. The term “about” generally refers to a range of numbers that one of skill in the art would consider equivalent to the recited value (for example, having the same function or result). In many instances, the term “about” may include numbers that are rounded to the nearest significant figure.

In everyday usage, indefinite articles (like “a” or “an”) precede countable nouns and noncountable nouns almost never take indefinite articles. It must be noted, therefore, that, as used in this specification and in the claims that follow, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a support” includes a plurality of supports. Particularly when a single countable noun is listed as an element in a claim, this specification will generally use a phrase such as “a single.” For example, “a single support.”

Where a range of values is provided, it is understood that each intervening value, to the tenth of the unit of the lower limit (unless the context clearly dictates otherwise), between the upper and lower limit of that range, and any other stated or intervening value in that stated range, is encompassed within the disclosure. The upper and lower limits of these smaller ranges may independently be included in the smaller ranges and are also encompassed within the disclosure, subject to any specifically excluded limit in the stated range. Where the stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included in the disclosure.

Fibrous structures such as sanitary tissue products, including paper towels, bath tissues and facial tissues are typically made in “wet-laid” papermaking processes. In such papermaking processes, a fiber slurry, usually wood pulp fibers, is deposited onto a forming wire and/or one or more papermaking belts such that a nascent fibrous structure is formed. After drying and/or bonding the fibers of the nascent fibrous structure together, a fibrous structure is formed. Further processing of the fibrous structure may then be carried out after the papermaking process. For example, the fibrous structure may be wound on the reel and/or ply-bonded and/or embossed. As further discussed herein, visually distinct features may be imparted to the fibrous structures in different ways. In a first method, the fibrous structures may have visually distinct features added during the papermaking process. In a second method, the fibrous structures may have visually distinct features added during the converting process (i.e., after the papermaking process). Some fibrous structure examples disclosed herein may have visually distinct features added only during the papermaking process, and some fibrous structure examples may have visually distinct features added both during the papermaking process and the converting process.

Regarding the first method, a wet-laid papermaking process may be designed such that the fibrous structure has visually distinct features “wet-formed” during the papermaking process. Any of the various forming wires and papermaking belts utilized may be designed to leave physical, three-dimensional features within the fibrous structure. Such three-dimensional features are well known in the art, particularly in the art of “through air drying” (TAD) papermaking processes, with such features often being referred to in terms of “knuckles” and “pillows.”

“Knuckles,” or “knuckle regions,” are typically relatively high-density regions that are wet-formed within the fibrous structure (extending from a pillow surface of the fibrous structure) and correspond to the knuckles of a papermaking belt, i.e., the filaments or resinous structures that are raised at a higher elevation than other portions of the belt. The knuckles of a papermaking belt may also be referred to as knuckle-forming elements.

“Relatively high density” as used herein means a portion of a fibrous structure having a density that is higher than a relatively low-density portion of the fibrous structure. Relatively high density may be about 0.5 g/cm³, whereas a relatively low density may be less than about 0.4 g/cm³. Likewise, “pillows,” or “pillow regions,” are typically relatively low-density regions that are wet-formed within the fibrous structure and correspond to the relatively open regions between or around the knuckles of the papermaking belt. These relatively open regions between or around the knuckle-forming elements of a paper-making belt may also be referred to as pillow-forming regions, pillow regions, or deflection conduit. The pillow regions may form a pillow surface of the fibrous structure from which the knuckle regions extend.

“Relatively low density” as used herein means a portion of a fibrous structure having a density that is lower than a relatively high-density portion of the fibrous structure.

Further, the knuckles and pillows wet-formed within a fibrous structure may exhibit a range of basis weights and/or densities relative to one another, as varying the size of the knuckles or pillows on a papermaking belt may alter such basis weights and/or densities. A fibrous structure (e.g., sanitary tissue products) made through a TAD papermaking process as detailed herein is known in the art as “TAD paper.”

In the description herein, the terms “knuckles” or “knuckle regions,” or the like may be used to reference either the raised portions of a papermaking belt or the densified, raised portions wet-formed within the fibrous structure made on the papermaking belt (i.e., the raised portions that extend from a surface of the fibrous structure), and the meaning should be clear from the context of the description herein. Likewise, “pillows” or “pillow regions” or the like may be used to reference either the portion of the papermaking belt between or around knuckles (also referred to herein and in the art as “deflection conduits” or “pockets”), or the relatively uncompressed regions wet-formed between or around the knuckles within the fibrous structure made on the papermaking belt, and the meaning should be clear from the context of the description herein. Knuckles or pillows may each be either continuous or discrete, as described herein.

A “structuring layer” refers to a patterned structure that may be integral with or affixed to a papermaking belt. The structuring layer may provide knuckle-forming elements that are elevated relative to a supporting layer upon which the structuring layer is affixed. The structuring layer may also provide pillow-forming regions in the spaces between the knuckle-forming elements.

A “mask” refers to a material, precisely patterned or shaped to selectively block or allow the passage of specific wavelengths or types of radiation. It enables the controlled exposure of radiation-sensitive materials or processes, resulting in the formation of desired patterns, structures, or features on the underlying substrate. The mask may comprise a plurality printed portions that may be spaced apart. The mask may be used in producing structuring layers on papermaking belts that would create fibrous structures that have discrete knuckles and continuous/substantially continuous pillows.

The term “discrete” as used herein with respect to knuckles and/or pillows means a portion of a papermaking belt or fibrous structure that is defined or surrounded by, or at least mostly defined or surrounded by, a continuous/substantially continuous knuckle or pillow. The term “continuous/substantially continuous” as used herein with respect to knuckles and/or pillows means a portion of a papermaking belt or fibrous structure network that fully, or at least mostly, defines or surrounds a discrete knuckle or pillow. Further, the substantially continuous member may be interrupted by macro patterns formed in the papermaking belt, as disclosed in U.S. Pat. No. 5,820,730 issued to Phan et al. on Oct. 13, 1998.

Knuckles and pillows in paper towels and bath tissue may be visible to the retail consumer of such products. The knuckles and pillows may be imparted to a fibrous structure from a papermaking belt at various stages of the papermaking process (i.e., at various consistencies and at various unit operations during the drying process) and the visual pattern generated by the pattern of knuckles and pillows may be designed for functional performance enhancement as well as to be visually appealing. Such patterns of knuckles and pillows may be made according to the methods and processes described in U.S. Pat. No. 6,610,173, issued to Lindsay et al. on Aug. 26, 2003, or U.S. Pat. No. 4,514,345 issued to Trokhan on Apr. 30, 1985, or U.S. Pat. No. 6,398,910 issued to Burazin et al. on Jun. 4, 2002, or US Pub. No. 2013/0199741; published in the name of Stage et al. on Aug. 8, 2013. The Lindsay, Trokhan, Burazin and Stage disclosures describe belts that are representative of papermaking belts made with cured resin on a woven reinforcing member, of which aspects of the present disclosure are an improvement. But in addition, the improvements detailed herein may be utilized as a fabric crepe belt as disclosed in U.S. Pat. No. 7,494,563, issued to Edwards et al. on Feb. 24, 2009 or U.S. Pat. No. 8,152,958, issued to Super et al. on Apr. 10, 2012, as well as belt crepe belts, as described in U.S. Pat. No. 8,293,072, issued to Super et al on Oct. 23, 2012. When utilized as a fabric crepe belt, a papermaking belt of the present disclosure may provide the relatively large, recessed pockets and sufficient knuckle dimensions to redistribute the fiber upon high impact creping in a creping nip between a backing roll and the fabric to form additional bulk in conventional wet-laid press processes. Likewise, when utilized as a belt in a belt crepe method, a papermaking belt of the present disclosure may provide the fiber enriched dome regions arranged in a repeating pattern corresponding to the pattern of the papermaking belt, as well as the interconnected plurality of surrounding areas to form additional bulk and local basis weight distribution in a conventional wet-laid process. In addition, the improvements detailed herein, including the formation of discrete cells comprising irregular cells arranged in substantially aligned rows, may be utilized as an uncreped through air dried (UCTAD) belt. UCTAD (un-creped through air drying) is a variation of the TAD process in which the sheet is not creped, but rather dried up to 99% solids using thermal drying, removed from the structured fabric, and then optionally calendered and reeled. U.S. Pat. No. 6,808,599 describes an uncreped through air dried process. U.S. Pat. No. 10,610,063 describes an uncreped through air dried product made using a belt. In addition, the improvements herein may be utilized as an ATMOS belt. The ATMOS process has been developed by the Voith company and marketed under the name ATMOS. The process/method and paper machine system has several variations, but all involve the use of a structured fabric in conjunction with a belt press. This process is described in numerous patent publications including U.S. Pat. Nos. 7,510,631, 7,686,923, 7,931,781, 8,075,739, and 8,092,652. In addition, the improvements herein may be utilized as an NTT belt. The NTT process has been developed by the Metso company and marketed under the name NTT. The NTT process includes an extended press nip where the sheet is transferred from a press felt onto a texturing belt. Examples of texturing belts used in the NTT process may be viewed in International Publication Number WO 2009/067079 A1 and US Patent Application Publication No. 2010/0065234 A1. As said, all such processes of this paragraph may be utilized to form the discrete cells of the present disclosure.

“Cell” may refer to an element on a papermaking belt or to an element of a fibrous structure. For example, “cell” may refer to a knuckle-forming element or a pillow-forming region of a structuring layer on a papermaking belt or a mask used to produce such a structuring layer. Additionally, “cell” may also refer to a knuckle or a pillow of a fibrous structure. Since the shape and orientation of elements on the papermaking belt are transferred to the fibrous structure, it is convenient to provide simplified illustrations of “cells” with the understanding that the cells shown may represent knuckle-forming elements, pillow-forming regions, knuckles, or pillows.

“Irregular” may refer to a characteristic of a feature or a pattern of features, such as a single cell or a group of cells. In this context, “irregular” indicates that cells are not uniform in shape, size, and/or arrangement. “Irregular” may mean that the individual cell or pattern of cells may lack symmetry, having no axis about which the cell or the pattern is mirrored.

Papermaking Belt

An example of a papermaking belt structure of the general type useful in the present disclosure and made according to the disclosure of U.S. Pat. No. 4,514,345 is shown in FIG. 1. As shown, the papermaking belt 10 may comprise a woven reinforcing member 11 formed by one or more woven filaments 12, as is known in the art of papermaking belts, for example resin coated papermaking belts. A structuring layer 20 may be affixed to or integral with the papermaking belt 10. The structuring layer 20 may comprise one or more knuckles or knuckle-forming elements 21. The knuckle-forming elements 21 may comprise cured resin elements 21a. The knuckle-forming elements 21 may be disposed on the woven reinforcing member 11. The knuckle-forming elements 21 may be spaced apart to define one or more pillow-forming regions 22. The specific papermaking belt 10 shown in FIG. 1 includes discrete knuckle-forming elements 21d and a continuous deflection conduit, or pillow-forming region 22c. The discrete knuckle-forming elements 21d may wet-form densified knuckles within the fibrous structure made thereon; and, likewise, the continuous deflection conduit, i.e. pillow-forming region 22c, may wet-form a continuous pillow region within the fibrous structure made thereon. The knuckle-forming elements 21 may be arranged in a pattern described with reference to an X-Y coordinate plane 60, having an x-axis 60x and a y-axis 60y, which may be defined relative to the papermaking belt 10, relative to the structuring layer 20, or relative to a fibrous structure 30 produced thereon. A distance between knuckle-forming elements 21 in at least one of the X or Y directions may vary according to the examples disclosed herein. For clarity, a fibrous structure's visually distinct knuckle(s) and pillow(s) that are wet-formed in a wet-laid papermaking process are different from, and independent of, any further structure added to the fibrous structure during later, optional, converting processes (e.g., one or more embossing processes).

Fibrous Structures

The fibrous structures of the present disclosure may be single-ply or multi-ply and may comprise cellulosic pulp fibers. Other naturally-occurring and/or non-naturally occurring fibers may also be present in the fibrous structures. In some examples, the fibrous structures may be wet-formed and through-air dried (TAD) in a TAD process, thus producing TAD paper. The fibrous structures may be marketed as single- or multi-ply sanitary tissue products.

The fibrous structures detailed herein will be described in the context of paper towels and bath tissue, and in the context of a papermaking belt comprising cured resin on a woven reinforcing member. However, the scope of disclosure is not limited to paper towels (scope also includes, for example, other sanitary tissues such as napkins and facial tissue) and includes other known processes that impart the knuckles and pillow patterns described herein, including, for example, the fabric crepe and belt crepe processes described above, and modified as described herein to produce the papermaking belts and paper as detailed herein.

In general, examples of the fibrous structures may be made in a process utilizing a papermaking belt that has a pattern of cured resin knuckle-forming elements on a woven reinforcing member of the type described in reference to FIG. 1. The resin pattern may be dictated by a patterned mask having opaque regions and transparent regions. The transparent regions may permit curing radiation to penetrate and to cure the resin, while the opaque regions may prevent the radiation from curing portions of the resin. Once curing is achieved and the patterned mask is removed, the uncured resin may be washed away to leave a pattern of cured resin that may be substantially identical to the mask pattern. The cured resin portions may be the knuckle-forming elements of the papermaking belt, and the areas between/around the cured resin portions may be the pillow-forming regions or deflection conduits of the belt. Thus, the mask pattern is replicated in the cured resin pattern of the papermaking belt, which may be essentially replicated again in the fibrous structure made on the papermaking belt. Therefore, in describing the fibrous structures' patterns of knuckles and pillows herein, a description of the patterned mask may serve as a proxy.

One skilled in the art will understand that the dimensions and appearance of the patterned mask are essentially identical to the dimensions and appearance of the papermaking belt made through utilization of the mask. One skilled in the art will further understand that the dimensions and appearance of the wet-laid fibrous structure made on the papermaking belt may also be essentially identical to the dimensions and appearance of the patterned mask. Further, in processes that use a papermaking belt that are not made from a mask, the dimensions and appearance of the papermaking belt may also be imparted to the fibrous structure, such that the dimensions of features of such papermaking belt may also be measured and characterized as a proxy for the dimensions and characteristics of the fibrous structure produced thereon. Creping on the paper machine may shrink or expand certain aspects of the dimensions, however the overall pattern will be substantially similar.

After completion of the papermaking process, a second way to provide visually distinct features to a fibrous structure is through embossing. Embossing is a well-known converting process in which at least one embossing roll having a plurality of discrete embossing elements extending radially outwardly from a surface thereof may be mated with a backing, or anvil, roll to form a nip in which the fibrous structure may pass such that the discrete embossing elements compress the fibrous structure to form relatively high density discrete elements (“embossed regions”) in the fibrous structure while leaving an uncompressed, or substantially uncompressed, relatively low density continuous, or substantially continuous, network (“non-embossed regions”) at least partially defining or surrounding the relatively high density discrete elements.

Embossed features in paper towels and bath tissues may be visible to the retail consumer of such products. Such patterns are well known in the art and may be made according to the methods and processes described in US Pub. No. US 2010-0028621 A1 in the name of Byrne et al. or US 2010-0297395 A1 in the name of Mellin, or U.S. Pat. No. 8,753,737 issued to McNeil et al. on Jun. 17, 2014. For clarity, such embossed features may originate during the converting process, and are different from, and independent of, the pillow and knuckle features that are wet-formed on a papermaking belt during a wet-laid papermaking process as described herein.

FIG. 2 illustrates a portion of a sheet on a roll 1 of fibrous substrate 30, such as a sanitary tissue or a paper towel, previously marketed by The Procter & Gamble Co. as BOUNTY® paper towels. While the actual papermaking belt and mask used to make the fibrous substrate 30 shown in FIG. 2 are not shown, it is to be appreciated that a papermaking belt of the general type shown in FIG. 1 was employed. As shown, fibrous substrate 30 exhibits a pattern of knuckles 31 which were formed by discrete cured resin knuckle-forming elements 21d on a papermaking belt 10.

The pattern of knuckles 31 and pillows 32 is considered the “wet-formed” background pattern, and the pattern of embossments 33 overlaid thereon is considered “dry-formed”. Thus, the pattern of knuckles and pillows and the embossments together give the paper towel its visual appearance. The previously marketed sanitary tissue products, an example of which is shown in FIG. 2, will be used to contrast the newly disclosed examples of fibrous structures detailed herein. Thus, the newly disclosed examples of fibrous structures detailed herein are an improvement over such previously marketed sanitary tissue products, with some of the improvements described below.

In one example, a fibrous structure of the present disclosure has a pattern of knuckles and pillows imparted to it by a papermaking belt having a corresponding pattern of knuckle-forming elements and pillow-forming regions that provides for superior product performance over known fibrous structures and is visually appealing to a retail consumer.

In another example, a fibrous structure of the present disclosure has a pattern of knuckles and pillows imparted to it by a papermaking belt having a corresponding pattern of knuckle-forming elements and pillow-forming regions, as well as an emboss pattern, which together provide for an overall visual appearance that is appealing to a retail consumer.

In another example, a fibrous structure of the present disclosure has a pattern of knuckles and pillows imparted to it by a papermaking belt having a corresponding pattern of knuckle-forming elements and pillow-forming regions, as well as an emboss pattern, which together provide for an overall visual appearance that is appealing to a retail consumer and exhibit superior product performance over known fibrous structures.

Conceptual Cells and Cell Patterns

Again, as used herein, the term “cell” may be used to represent a discrete element of a mask, a papermaking belt, a structuring layer on a papermaking belt, or a fibrous structure such as a sanitary tissue or a paper towel. Thus, FIG. 3 may be viewed as a representation of a structuring layer 20, a fibrous substrate 30, or mask 100 that may be used to produce a structuring layer 20. When viewed as a representation of a structuring layer 20 used to produce a fibrous substrate 30, the cells 40 may represent knuckle-forming regions or pillow-forming regions. When viewed as a representation of a fibrous substrate 30, the cells 40 may represent knuckles or pillows. When viewed as a mask, the cells may represent transparent portions or opaque portions.

The method of identifying one or more cells from a fibrous sample may be determined according to the Micro-CT Intensive Property Method herein. In FIG. 3, the schematic representation of cells 40 may be considered representations of a discrete element of one or more transparent portions of a mask, one or more knuckles on a papermaking belt, or one or more knuckles in a fibrous structure. But the examples detailed herein are not limited to one method of making, so the term “cell” may refer to a discrete feature such as a raised element, a dome-shaped element or knuckle formed by belt or fabric creping on a fibrous structure, for example. The term “cell” may also represent discrete transparent or opaque portions of a mask, a discrete deflection conduit in a papermaking belt, or a discrete relatively low density/basis weight portion of a fibrous structure.

Referring again to FIG. 2, a fibrous substrate 30 may exhibit a pattern of knuckles 31 which were formed by discrete cured resin knuckles 21d on a papermaking belt 10. These knuckles may correspond to the black areas, referred to as cells 40 of the mask 100 shown in FIG. 3. As more clearly seen in the mask of FIG. 3, the cell 40 shape and orientation are both constant and the cells are ordered in straight rows 51x, 51y. One set of rows 51x is oriented in a direction that is parallel to an X-axis of the mask 100 (i.e., in an X-direction) and one set of rows 51y is oriented in a direction that is parallel to an Y-axis of the mask 100 (i.e., in a Y-direction). In other words, all cells 40 of the mask/fibrous structure will be a member of a row 51x that is oriented in an X-direction and will also be a member of a row 51y that is oriented in a Y-direction.

Any portion of the pattern of FIG. 3 that is black may represent a transparent region of the mask, which permits radiative curing (such as via UV-light) of curable resin to form a knuckle on the papermaking belt. The inverse is also possible, in which black portions may represent opaque regions of the mask, which do not permit curing of a curable resin. This convention avoids unnecessary duplication of figures. After the mask is removed, the uncured resin is ultimately washed away to form a deflection conduit or a pillow-forming region on the papermaking belt. When a fibrous structure is made on the papermaking belt, the fibers will wet-form into the deflection conduit or pillow-forming region to form a relatively low-density pillow 22 within the fibrous structure. Again, it is to be appreciated, however, that FIG. 3 may also represent the inverse.

Generally, the fibrous structures illustrated herein either exhibit a structure of discrete pillows and a continuous/substantially continuous knuckle region, or a structure of discrete knuckles and a continuous/substantially continuous pillow region. However, for every example described or illustrated herein, the inverse of such structure is also contemplated. In other words, if a structure of discrete knuckles and a continuous/substantially continuous pillow region is shown, an inverse similar structure of continuous/substantially continuous knuckles and discrete pillows is also contemplated. Moreover, in regard to the papermaking belts, as may be understood by the description herein, the inverse relationship may be achieved by inverting the black and white (or, more generally, the opaque and transparent) portions of the mask used to make the belt that is used to make the fibrous structure. This inverse relation (black/white) may apply to all patterns of the present disclosure, although all fibrous structures/patterns of each category are not illustrated for brevity. Some specific papermaking belts and the process of making them are described in further detail below.

Masks, Structuring Layers on Papermaking Belts, and Fibrous Structures with Conceptual Cells

FIG. 4 is a top view of a mask 100 that may be used to produce a structuring layer 20 on a papermaking belt 10 (See FIG. 5, for example). The mask 100 may comprise conceptual cells 40 in the form of transparent portions 102 and/or in the form of opaque portions 104.

FIG. 5 is an isometric view of a structuring layer 20 on a papermaking belt 10 that includes a plurality of conceptual cells 40 in the form of knuckle-forming elements 21 as well as pillow-forming regions 22 therebetween. The knuckle-forming elements 21 correspond to the transparent portions 102 of the mask 100 shown in FIG. 4, indicating that these knuckle-forming elements 21 may have been formed by passing radiation through the transparent portions 102 to cure a resin on the papermaking belt 10. Uncured portions of the resin that were beneath the opaque portions 104 of the mask 100 may have been washed away to leave the pillow-forming regions 22.

FIG. 6 is an isometric view of a fibrous structure 30 that may be produced with the structuring layer 20 shown in FIG. 5, the fibrous structure 30 comprising conceptual cells 40 in the form of higher-density knuckles 31 as well as lower-density pillows 32 therebetween. It is to be understood that FIG. 6 is only a conceptual, schematic representation; the crisp edges and corners shown in FIG. 6 would typically be more rounded providing a smoother transition between the knuckles 31 and the pillows 32.

Elements of Conceptual Cells

FIG. 7 is a plan view of a conceptual cell 40. The conceptual cell 40 may represent a portion of a papermaking belt 10 such as a knuckle-forming element 21 or a pillow-forming region 22 of a structuring layer 20. The conceptual cell 40 may represent a knuckle 31 or a pillow 32 of a fibrous structure 30. The conceptual cell 40 may also represent a transparent portion 102 or an opaque portion 104 of a mask 100 that may be used to produce a structuring layer 20 on a papermaking belt 10. It is to be appreciated that throughout this disclosure reference to a cell 40 is intended to include an optional reference to any of a knuckle-forming element 21, a pillow-forming region 22, a knuckle 31, a pillow 32, a transparent portion 102, or an opaque portion 104, even if specific reference is omitted to any or all of these elements. A major coordinate plane 60 may be defined relative to the papermaking belt 10, the structuring layer 20, the mask 100, or the fibrous structure 30, as appropriate for the context. The major coordinate plane 60 may comprise an x-axis 60x and a y-axis 60y. The cell 40 may have a position 42 on the papermaking belt 10, the structuring layer 20, the mask 100, or the fibrous structure 30. The position 42 of the cell 40 may define its location on the major coordinate plane 60. The position 42 of the cell 40 may be at a centroid C of the cell 40 as defined by a perimeter 44 of the cell 40. The “centroid” of an irregularly shaped object is the point that represents the center of mass of the object. It is the point at which a cutout of the object would balance on a pin.

A minor coordinate system 41 may be centered on the position 42 of the cell 40 and, as will be discussed hereinafter, may be useful to compare the relative rotation of cells 40 relative to the major coordinate system 60 or relative to each other. The minor coordinate system 41 may comprise an x-axis 41x and a y-axis 41y. The cell 40 may be oriented at an angle 43 relative to the major coordinate system. The angle 43 may be measured between an axis of the minor coordinate system 41, such as y-axis 41y and an axis of the major coordinate system 60, such as y-axis 60y. The angle 43 may be about 0 degrees to about 180 degrees, 0 degrees to about 180 degrees, or about 15 degrees to about 165 degrees, or about 30 degrees to about 150 degrees, or about 45 degrees to about 135 degrees, or about 60 degrees to about 120 degrees, or about 75 degrees to about 105 degrees, or about 90 degrees.

The cell 40 may have a uniform (solid) or nonuniform (not solid) structure. For example, as shown in FIG. 7, the perimeter 44 of the cell 40 may surround a uniform structure. The uniform structure may be a knuckle-forming element 21 or a pillow-forming region 22 of a structuring layer 20 or a papermaking belt 10 or may be a transparent portion 102 or an opaque portion 104 of a mask 100 used to make a structuring layer 20. The uniform structure may be a knuckle 31 or a pillow 32 of a fibrous structure 30. On the other hand, as shown in the perimeter 44 of the cell 40 may surround a nonuniform structure. The nonuniform structure may comprise a knuckle-forming element 21 and a pillow-forming region 22 of a structuring layer 20 or papermaking belt 10 or may be a transparent portion 102 or an opaque portion 104 of a mask 100 used to make a structuring layer 104. The nonuniform structure may comprise a knuckle 31 and a pillow 32 of a fibrous structure 30.

The cell 40 may have a non-center facing side 45 and a center facing side 46. The meaning of the terms “non-center facing” and “center-facing” will become clearer in view of FIG. 8. The non-center facing side 45 may have a length 45L. The center-facing side 46 may have a length 46L. The non-center facing side 45 may comprise one or more curved segments 45c and/or one or more straight segments 45s. The center-facing side 46 may also comprise one or more curved segments 45c (Not shown in FIG. 8; See: FIGS. 11, 13, 16, 18, 20, 22, 23, 24, 25, 26, 27, 28, 29, 31, and 32) and/or one or more straight segments 45s. The non-center facing side 45 and the center-facing side 46 may optionally be separated or demarcated by one or more vertices 47. As used herein, a “vertex” or “vertices” (plural) is a point (or points) where two or more sides (or edges) of a shape meet along its perimeter, effectively serving as a corner or junction. In polygons, such as triangles, squares, or pentagons, each vertex marks the end of one side and the beginning of another, demarcating the sides of the shape.

Cell Cluster Characteristics

FIG. 8 is a plan view of a cell cluster 70 comprising a plurality of conceptual cells 40a, 40b, 40c, 40d having different positions and rotations relative to a major coordinate plane 60 that may be defined by a papermaking belt 10, a structuring layer 20, a mask 100, or a fibrous structure 30. The major coordinate plane 60 may comprise an x-axis 60x and a y-axis 60y.

The first cell 40a may have a first minor coordinate system 41a comprising a first x-axis 411x and a first y-axis 411y. The first cell 40a may be oriented at a first angle 43a relative to the major coordinate plane 60. The first angle 43a may be measured between an axis, such as the first y-axis 411y, and an axis, such as the y-axis 60y, of the major coordinate plane 60. The first cell 40a may comprise a non-center facing side 45a and a center-facing side 46a.

The second cell 40b may have a second minor coordinate system 41b comprising a second x-axis 412x and a second y-axis 412y. The second cell 40b may be oriented at a second angle 43b relative to the major coordinate plane 60. The second angle 43b may be measured between an axis, such as the second y-axis 412y, and an axis, such as the y-axis 60y, of the major coordinate plane 60. The second cell 40b may comprise a non-center facing side 45b and a center-facing side 46b. The third cell 40c may have a third minor coordinate system 41c comprising a third x-axis 413x and a third y-axis 413y. The third cell 40c may be oriented at a third angle 43c relative to the major coordinate plane 60. The third angle 43c may be measured between an axis, such as the third y-axis 413y, and an axis, such as the y-axis 60y, of the major coordinate plane 60. The third cell 40c may comprise a non-center facing side 45c and a center-facing side 46c.

The fourth cell 40d may have a fourth minor coordinate system 41d comprising a fourth x-axis 414x and a fourth y-axis 414y. The fourth cell 40d may be oriented at a fourth angle 43d relative to the major coordinate plane 60. The fourth angle 43d may be measured between an axis, such as the fourth y-axis 414y, and an axis, such as the y-axis 60y, of the major coordinate plane 60. The fourth cell 40d may comprise a non-center facing side 45d and a center-facing side 46d.

As shown the cells 40a, 40b, 40c, 40d have the same shapes and the same sizes. It is to be appreciated that other variations are possible, such as different shapes, different sizes or same angles and combinations therein.

The cell cluster 70 of conceptual cells 40a, 40b, 40c, 40d may comprise a minor coordinate system 71, having a y-axis 71y and an x-axis 71x. The minor coordinate system 71 may be positioned at a cluster centroid CC of the cell cluster 70. The cluster centroid CC may also define a position 72 of the cell cluster 70 relative to the major axis 60. The cell cluster 70 may be oriented at an angle 73 relative to the major coordinate plane 60. The angle 73 may be measured between an axis, such as the cell cluster y-axis 71y, and an axis, such as the y-axis 60y, of the major coordinate plane 60.

The cell cluster 70 may also have an outer perimeter 76, defined by the maximal extents of all the non-center facing surfaces 45 of cells 40 within the cell cluster 70 relative to the cluster centroid CC. For example, an outer perimeter 76 is defined for the cell cluster 70 shown in FIG. 8 by the maximal extents of non-center facing surfaces 45a, 45b, 45c, 45d relative to the cluster centroid CC. It is to be appreciated that in FIG. 8, the perimeter 76 is drawn slightly larger than the actual perimeter 76 for the sake of visibility. The actual perimeter 76 would overlap with the non-center facing surfaces 45a, 45b, 45c, 45d.

FIG. 9 is a plan view of a cell cluster 70 showing a cluster-qualifying radius 70r about a centroid CC of the cell cluster 70 within which all center-facing sides 46 of each cell 40 in the cell cluster 70 must be positioned. The cell cluster 70 may have a length 70L and a width 70W, that is perpendicular to the length 70L. The length 70L and the width 70W may be defined by maximum extents of non-center facing sides 45 of cells having a center-facing side 46 within the cluster-qualifying radius 70r. The cluster-qualifying radius 70r may be less than a width 70W of the cell cluster 70 and/or may be less than a length of the cell cluster 70. The cluster-qualifying radius 70r may help distinguish cells 40 that are part of a cell cluster 70 and adjacent cells 40 that are not part of the cell cluster 70. The cluster-qualifying radius 70r may be in a range of from about 0.75 mm (˜30 mils) to about 1.3 mm (˜50 mils), or about 2.5 mm (˜100 mils).

The length 70L and/or the width 70W of each cell cluster 70 may be from greater than about 2 mm to about 10 mm, or from about 3 mm to about 9 m, or from about 4 mm to about 8 mm, or from about 5 mm to about 7 mm.

Each cell cluster 70 comprises at least 2 cells. For example, each cell cluster 70 may comprise from 2 to 50 cells, or from 5 to 40 cells, or 10 to 30 cells.

The perimeter 76 of each cell cluster 70 may have a shape selected from an n-sided polygon, a circle, and an oval, wherein n is from 3 to 30, or from 4 to 20, or from 5 to 14, or from 6 to 10, or from 6 to 9, or 8.

Supported Central Area of a Cell Cluster

FIG. 10 is a plan view of a cell cluster 70 comprising a plurality of conceptual cells 40 surrounding a supported central area 74. The supported central area 74 may be a pillow region of a fibrous structure 30 that is supported by the surrounding cells 40, which may be knuckles. In that case, the surrounding knuckles may support the pillow region by preventing it from being distorted or collapsing. The supported central area 74 may have a shape 74s that is defined at least partially by the center-facing sides 46 of the cells 40 that make up the cell cluster 70. As shown in FIG. 10, the shape 74s is a square, because a square is the simplest shape that may be defined by all of the center-facing sides 46. The supported central area 74 may have a length 74W and a width 74L, which may be defined by the maximum extents of the supported central area 74 from the cluster centroid CC.

The supported central area 74 may have an area of from greater than about 1.9 mm² to about 10 mm², or from about 2 mm² to about 8 mm², or from about 4 mm² to about 6 mm². The supported area may have a shape selected from an n-sided polygon, a circle, and an oval, wherein n is from 3 to 30, or from 4 to 20, or from 5 to 14, or from 6 to 10, or from 6 to 9, or 8.

The supported area may have an aspect ratio of from about 1:1 to about 1:8, or from about 1:2 to about 1:7, or from about 1:3 to about 1:6, or from about 1:4 to about 1:5.

Intra-Cluster Channels

FIG. 11 is a plan view of a cell cluster 70 comprising a plurality of conceptual cells 40 showing intra-cluster channels 75 extending between the conceptual cells 40. The intra-cluster channels 75 may extend through the supported area 74 and may be defined at least partially by non-center facing sides 45 of the cells 40. It is to be appreciated that the intra-cell channels 75 shown in FIG. 11 have been drawn slightly smaller so that their boundaries are visible. The actual boundaries would partially overlap the non-center facing sides 45 of the cells 40. Each intra-cell channel 75 may have a length 75L and a width 75W.

Exemplary Cell Clusters

FIG. 12 is a plan view of a cell cluster 70 having a supported central area 74 having a shape 74s that is circular and showing intra-cluster channels 75 extending between the conceptual cells 40. The center-facing sides 46 comprise curved segments 46c and the simplest shape defined by all of the center-facing sides 46 is a circle.

FIG. 13 is a plan view of a cell cluster 70 having a supported central area 74 having a shape 74s that is octagonal and showing intra-cluster channels 75 extending between the conceptual cells 40. Each of the center-facing sides 46 may comprise straight segments 46s and the simplest shape defined by all of the center-facing sides 46 is an octagon.

FIG. 14 is a plan view of a cell cluster 70 having a supported central area 74 having a shape 74s that is circular and showing intra-cluster channels 75 extending between the conceptual cells 40. The center-facing sides 46 comprise curved segments 46c and the simplest shape defined by all of the center-facing sides 46 is a circle.

FIG. 15 is a plan view of a cell cluster 70 having a supported central area 74 having a shape 74s that is octagonal and showing intra-cluster channels 75 extending between the conceptual cells 40. Each of the center-facing sides 46 may comprise straight segments 46s and the simplest shape defined by all of the center-facing sides 46 is an octagon.

FIG. 16 is a plan view of a cell cluster 70 having a supported central area 74 having a shape 74s that is square with corner radiuses and showing intra-cluster channels 75 extending between the conceptual cells 40. The shape 74s may also be a square without corner radiuses.

FIG. 17 is a plan view of a cell cluster 70 having a supported central area 74 having a shape 74s that is square with corner radiuses and showing intra-cluster channels 75 extending between the conceptual cells 40. Each of the center-facing sides 46 may comprise straight segments 46s and a curved segment 46c and the simplest shape defined by all of the center-facing sides 46 is a square with corner radiuses.

FIG. 18 is a plan view of a cell cluster 70 having a supported central area 74 having a shape 74s that is square with corner radiuses and showing intra-cluster channels 75 extending between the conceptual cells 40. The shape 74s may also be a square without corner radiuses.

FIG. 19 is a plan view of a cell cluster 70 having a supported central area 74 having a shape 74s that is square with corner radiuses and showing intra-cluster channels 75 extending between the conceptual cells 40. Each of the center-facing sides 46 may comprise straight segments 46s and a curved segment 46c and the simplest shape defined by all of the center-facing sides 46 is a square with corner radiuses.

FIG. 20 is a plan view of a cell cluster 70 having a supported central area 74 having a shape 74s that is hexagonal and showing intra-cluster channels 75 extending between the conceptual cells 40. Each of the center-facing sides 46 may comprise straight segments 46s and the simplest shape defined by all of the center-facing sides 46 is a hexagon.

FIG. 21 is a plan view of a cell cluster 70 having a supported central area 74 having a shape 74s that is circular and showing intra-cluster channels 75 extending between the conceptual cells 40. The center-facing sides 46 comprise curved segments 46c and the simplest shape defined by all of the center-facing sides 46 is a circle.

FIG. 22 is a plan view of a cell cluster 70 having a supported central area 74 having a shape 74s that is hexagonal and showing intra-cluster channels 75 extending between the conceptual cells 40. Each of the center-facing sides 46 may comprise a straight segment 46s and the simplest shape defined by all of the center-facing sides 46 is a hexagon.

FIG. 23 is a plan view of a cell cluster 70 having a supported central area 74 having a shape 74s that is circular and showing intra-cluster channels 75 extending between the conceptual cells 40. The center-facing sides 46 comprise curved segments 46c and the simplest shape defined by all of the center-facing sides 46 is a circle.

FIG. 24 is a plan view of a cell cluster 70 having a supported central area 74 having a shape 74s that is oval and showing intra-cluster channels 75 extending between the conceptual cells 40. The center-facing sides 46 comprise curved segments 46c and the simplest shape defined by all of the center-facing sides 46 is an oval. As shown, the length 74L and the width 74W of the supported central area 74 may be different.

FIG. 25 is a plan view of a cell cluster 70 having a supported central area 74 having a shape 74s that is oval and showing intra-cluster channels 75 extending between the conceptual cells 40. The center-facing sides 46 comprise curved segments 46c and the simplest shape defined by all of the center-facing sides 46 is an oval.

FIG. 26 is a plan view of a cell cluster 70 having a supported central area 74 having a shape 74s that is oval and showing intra-cluster channels 75 extending between the conceptual cells 40. The center-facing sides 46 comprise curved segments 46c and the simplest shape defined by all of the center-facing sides 46 is an oval.

FIG. 27 is a plan view of a cell cluster 70 having a supported central area 74 having a shape 74s that is oval and showing intra-cluster channels 75 extending between the conceptual cells 40. The center-facing sides 46 comprise curved segments 46c and the simplest shape defined by all of the center-facing sides 46 is an oval.

FIG. 28 is a plan view of a cell cluster 70 having a supported central area 74 having a shape 74s that is circular and showing intra-cluster channels 75 extending between the conceptual cells 40. The center-facing sides 46 comprise curved segments 46c and the simplest shape defined by all of the center-facing sides 46 is an oval.

FIG. 29 is a plan view of a cell cluster 70 having a supported central area 74 having a shape 74s that is circular and showing intra-cluster channels 75 extending between the conceptual cells 40. The center-facing sides 46 comprise curved segments 46c and the simplest shape defined by all of the center-facing sides 46 is an oval.

FIG. 30 is a plan view of a cell cluster 70 having a supported central area 74 having a shape 74s that is circular and showing intra-cluster channels 75 extending between the conceptual cells 40. The center-facing sides 46 comprise curved segments 46c and the simplest shape defined by all of the center-facing sides 46 is an oval.

FIGS. 31, 32, and 33 demonstrate that the cells 40 that make up a cell cluster may have different shapes and sizes. FIG. 31 is a plan view of a cell cluster 70 having a supported central area 74 having a shape 74s that is circular and showing intra-cluster channels 75 extending between the conceptual cells 40. The center-facing sides 46 comprise curved segments 46c and the simplest shape defined by all of the center-facing sides 46 is an oval. FIG. 32 is a plan view of a cell cluster 70 having a supported central area 74 having a shape 74s that is circular and showing intra-cluster channels 75 extending between the conceptual cells 40. The center-facing sides 46 comprise curved segments 46c and the simplest shape defined by all of the center-facing sides 46 is an oval. FIG. 33 is a plan view of a cell cluster 70 having a supported central area 74 having a shape 74s that is circular and showing intra-cluster channels 75 extending between the conceptual cells 40. The center-facing sides 46 comprise curved segments 46c and the simplest shape defined by all of the center-facing sides 46 is an oval.

FIG. 34 is a plan view of a cell cluster 70 with an outer perimeter 76 having a shape 76s that is square with radiused corners 77. FIG. 35 is a plan view of a cell cluster 70 with an outer perimeter 76 having a shape 76s that is square. FIG. 36 is a plan view of a cell cluster 70 with an outer perimeter 76 having a shape 76s that is hexagonal. FIG. 37 is a plan view of a cell cluster 70 with an outer perimeter 76 having a shape 76s that is circular. It is to be appreciated that the size of the outer perimeter 76 shown in each of FIGS. 34, 35, 36, and 37 is exaggerated to be larger for visibility. The actual perimeter 76 would overlap with the non-center facing sides 45.

FIG. 44 is a plan view of a cell cluster 70 having a supported central area 74 having a shape 74s that is partially circular and showing intra-cluster channels 75 extending between the conceptual cells 40. The center-facing sides 46 comprise curved segments 46c and the simplest shape defined by all of the center-facing sides 46 is a partial circle. Some of the conceptual cells 40 shown in FIG. 44, do not have any vertices 47 demarcating a center-facing side 46 from a non-center-facing side 45.

FIG. 45 is a plan view of a cell cluster 70 having a supported central area 74 having a shape 74s that is partially circular and showing intra-cluster channels 75 extending between the conceptual cells 40. The center-facing sides 46 comprise curved segments 46c and the simplest shape defined by all of the center-facing sides 46 is a partial circle. Some of the conceptual cells 40 shown in FIG. 45, do not have any vertices 47 demarcating a center-facing side 46 from a non-center-facing side 45.

Inter-Cluster Channels

FIG. 38 is a plan view of a channel-forming arrangement 80 of cell clusters 70a, 70b with an inter-cluster channel 83 wedge-shaped cross channel extending therebetween. The first cell cluster 70a may include one or more intra-cluster channels 75a. The second cell cluster 70b may also include one or more intra-cluster channels 75b. An intra-cluster channel 75a of the first cell cluster 70a may align linearly or curvilinearly with an intra-cluster channel 75b of the second cell cluster 70b to form an inter-cluster channel 83 extend through both the first cell cluster 70a and the second cell cluster 70b. Generally, an inter-cluster channel 83 may have a linear or curvilinear shape and may at least partially overlap with an intra-cluster channel 75a of a first cell cluster 70a and an intra-cluster channel 75b of a second cell cluster 70b to provide a continuous channel therethrough. According to one aspect of the disclosure, the cells 40 that make up the cell clusters 70a, 70b may represent knuckles 31 of a fibrous structure 30 and the intra-cluster channels 75a, 75b, the wedge-shaped cross channel 82, and the inter-cluster channel 83 may be pillows 32 therebetween. Again, it is to be appreciated that this is only one example and that a cell 40 may refer to any of a knuckle-forming element 21, a pillow-forming region 22, a knuckle 31, a pillow 32, a transparent portion 102, or an opaque portion 104.

Cross Channels

Still referring to FIG. 38, the channel-forming arrangement 80 of cell clusters 70a, 70b also includes a cross channel 82. Unlike the inter-cluster channel 83, the cross channel 82 does not overlap with intra-cluster channels 75a, 75b. The inter-cluster channel 83 may extend through a cross channel 83, if one is present between the cell clusters 70a, 70b. The cross-channel 82 may have a wedge-like shape, in which case the cross channel 82 may be referred to as a wedge-shaped cross channel 82. A wedge-shaped cross channel 82 may occur when adjacent cell clusters are oriented at different angles. For example, the first cell cluster 70a may have a minor coordinate system 71a that is oriented at an angle 73a relative to a major coordinate system 60 of a papermaking belt 10, a structuring layer 20, a fibrous substrate 30, or a mask 100. Similarly, the second cell cluster 70b may have a minor coordinate system 71b that is oriented at an angle 73b relative to the major coordinate system 60. The orientations and relative positions of the first cell cluster 70a and the second cell cluster 70b may form a wedge-shaped cross channel 82 therebetween. The wedge-shaped cross channel 82 may have a narrow portion 82n and a wide portion 82w and an angle 82. Although most of the examples presented herewith illustrate wedge-shaped cross channels 82, it is to be appreciated the a cross channel 82 may be straight or curved or have any shape.

Para-Cluster Channels

FIG. 39 is a plan view of a channel-forming arrangement 80 of cell clusters 70a, 70b, 70c, 70d with inter-cluster channels 82a, 82b, wedge-shaped cross channels 82a, 82b, and a para-cluster channel 84 extending therebetween. A para-cluster channel 83 may have a linear or curvilinear shape and may extend between cell clusters 70a, 70b, 70c, 70d to provide a continuous channel therebetween. Unlike an inter-cluster channel 83, a para-cluster channel 84 does not connect intra-cluster channels 82, but rather extends substantially parallel to intra-cluster channels 82. One or more supported portions 85 of a para-cluster channel 84 may exist between wedge-shaped cross channels 82a, 82b. For example, as shown a supported portion 85 of the para-cluster channel 84 is shown between a wide portion 82w of a first wedge-shaped cross channel 82a and a narrow portion 82n of a second wedge-shaped cross channel 82b. The wide portion 82w of the first wedge-shaped cross channel 82a may be said to be “supportively adjacent” to the para-cluster channel 84 since it is immediately next to the para-cluster channel 84 with no intervening structures and since it supports a portion 85 of the para-cluster channel 84. Similarly, the narrow portion 82n of the second wedge-shaped cross channel 82b may be said to be “supportively adjacent” to the para-cluster channel 84 since it is immediately next to the para-cluster channel 84 with no intervening structures and since it supports a portion 85 of the para-cluster channel 84. The supported portion 85 is of particular importance when the cells 40 that make up the cell clusters 70a, 70b represent knuckles 31 of a fibrous structure 30 and the intra-cluster channels 75a, 75b, the wedge-shaped cross channel 82, and the inter-cluster channel 83 represent pillows 32 therebetween. In that case, the structures like the knuckles 31 and the wedge-shaped cross channels 82a, 82b may help to prevent the pillow 32 from collapsing or deforming. Again, it is to be appreciated that this is only one example and that a cell 40 may refer to any of a knuckle-forming element 21, a pillow-forming region 22, a knuckle 31, a pillow 32, a transparent portion 102, or an opaque portion 104.

Intra-cluster channels 75 may be substantially parallel to a para-cluster channel and may also be “supportively adjacent” to a para-cluster channel 84. For example, FIG. 40 is a plan view of a channel-forming arrangement 80 of cell clusters 70a, 70b with a para-cluster channel 84 extending therebetween, each cell cluster 70a, 70b defining an intra-cluster channel 75a, 75b supportively-adjacent to the para-cluster channel 84. Each intra-cluster channel 75a, 75b may be said to be “supportively adjacent” to the para-cluster channel 84 since it is immediately next to the para-cluster channel 84 with no intervening structures and since it supports a portion 85 of the para-cluster channel 84. The first intra-cluster channel 75a may be on a first side 841 of the para-cluster channel 84 and the second intra-cluster channel 75b may be on a second side 842 of the para-cluster channel 84. The first intra-cluster channel 75a and the second intra-cluster channel 75b may be aligned (not shown) or not aligned as shown.

FIG. 41 is a plan view of a channel-forming arrangement 80 of cell clusters 70a, 70b, 70c, 70d, 70e, 70f with a para-cluster channel 84 extending therebetween, each cell cluster defining an intra-cluster channel 75a, 75b, 75c, 74d, 75e, 75f supportively-adjacent to the para-cluster channel 84, the cell clusters also defining wedge-shaped cross channels 82a, 82b, 82c, 82d supportively-adjacent to the para-cluster channel 84. The intra-cluster channels 83a and 84b may both have a width 83w, which may be the same or different. Similarly, the para-cluster channel 84 may have a width 84w that may be the same or different than the width 83w of the intra-cluster channels 83. The para-cluster channel 84 and the intra-clusters may be substantially parallel to each other.

A ratio of the width 84w of a para-cluster channel to the width 83w of a intra-cluster channel may be from about 1.25 to about 5, or about 1.5 to about 4.75, or about 1.75 to about 4.5, or about 2 to about 4.25, or about 2.25 to about 4, or about 2.5 to about 3.75, or about 2.75 to about 3.5, or about 3 to about 3.25.

The first intra-cluster channel 75a and the second intra-cluster channel 75b are supportively adjacent to opposite sides of the para-cluster channel 84 and provide support to a portion 85a of the para-cluster channel 84. Similarly, the third intra-cluster channel 75c and the fourth intra-cluster channel 75d are supportively adjacent to opposite sides of the para-cluster channel 84 and provide support to a portion 85c of the para-cluster channel 84. Finally, the fifth intra-cluster channel 75e and the sixth intra-cluster channel 75f are supportively adjacent to opposite sides of the para-cluster channel 84 and provide support to a portion 85e of the para-cluster channel 84.

The first wedge-shaped cross channel 82a and the second wedge shaped channel 82b are supportively adjacent to opposite sides of the para-cluster channel 84 and provide support to a portion 85b of the para-cluster channel 84. Similarly, the third wedge-shaped cross channel 82c and the fourth wedge shaped channel 82d are supportively adjacent to opposite sides of the para-cluster channel 84 and provide support to a portion 85d of the para-cluster channel 84.

FIG. 42 is a plan view of a channel-forming arrangement 80 of cell clusters with para-cluster channels 84 extending therebetween and illustrating the width 84w and spacing 84s of the para-cluster channels 84.

The width 84w of a para-cluster channel may be from greater than about 55 mils to about 500 mils, or about 80 mils to about 475 mils, or about 105 mils to about 450 mils, or about 130 mils to about 425 mils, or about 155 mils to about 400 mils, or about 180 mils to about 375 mils, or about 205 mils to about 350 mils, or about 230 mils to about 325 mils, or about 255 mils to about 300 mils

The spacing 84s between para-cluster channels may be from greater than about 100 mils to about 1000 mils, or about 125 mils to about 975 mils, or about 150 mils to about 950 mils, or about 175 mils to about 925 mils, or about 200 mils to about 900 mils, or about 225 mils to about 875 mils, or about 250 mils to about 850 mils, or about 275 mils to about 825 mils, or about 300 mils to about 800 mils, or about 325 mils to about 775 mils, or about 350 mils to about 750 mils, or about 375 mils to about 725 mils, or about 400 mils to about 700 mils, or about 425 mils to about 675 mils, or about 450 mils to about 650 mils, or about 475 mils to about 625 mils, or about 500 mils to about 600 mils, or about 525 mils to about 575 mils.

Useful Pattern

FIG. 43 is a plan view of a pattern 50 of cells 40 comprising a plurality of cell clusters 70 separated by para-cluster channels 84 and wedge-shaped cross channels 82. As shown, the para-cluster channels 84 may have a curvilinear, flowing path that changes directions multiple times across the pattern 50. It is to be appreciated that many other configurations are contemplated and within the scope of this disclosure.

Properties of the Fibrous Structure

The fibrous structures detailed herein may comprise one or more plies, such as for example, 2-ply. The fibrous structures may also be embossed. Nonlimiting examples of the new fibrous structures as detailed herein, including those using the cell pattern of FIG. 43, may exhibit any or all of the following properties:

A basis weight of between about 30 g/m² and about 100 g/m², or between about 40 g/m² and about 65 g/m², or between about 45 g/m² and about 60 g/m², or between about 50 g/m² and about 58 g/m², or between about 50 g/m² and about 55 g/m², specifically reciting all 0.1 g/m² increments within the above-recited ranges and all ranges formed therein or thereby.

A TS7 value of less than about 40.00 dB V² rms, or less than about 20.00 dB V² rms, or less than about 19.50 dB V² rms, or less than about 19.00 dB V² rms, or less than about 18.50 dB V² rms, or less than about 18.00 dB V² rms, or less than about 17.50 dB V² rms, or between about 0.01 dB V² rms and about 20.00 dB V² rms, or between about 0.01 dB V² rms and about 19.50 dB V² rms, or between about 0.01 dB V² rms and about 19.00 dB V² rms, or between about 0.01 dB V² rms and about 18.50 dB V² rms, or between about 0.01 dB V² rms and about 18.00 dB V² rms, or between about 0.01 dB V² rms and about 17.50 dB V² rms, or between about 5.0 dB V² rms and about 20.00 dB V² rms, or between about 10.00 dB V² rms and about 20.00 dB V² rms, or between about 12.00 dB V² rms and about 20.00 dB V² rms, specifically reciting all 0.01 dB V² rms increments within the above-recited ranges and all ranges formed therein or thereby.

An SST value (absorbency rate) of greater than about 0.80 g/sec^0.5, greater than about 1.60 g/sec^0.5, or greater than about 1.65 g/sec^0.5, or greater than about 1.70 g/sec^0.5, or greater than about 1.75 g/sec^0.5, or greater than about 1.80 g/sec^0.5, or greater than about 1.82 g/sec^0.5, or greater than about 1.85 g/sec^0.5, or greater than about 1.88 g/sec^0.5, or greater than about 1.90 g/sec^0.5, or greater than about 1.95 g/sec^0.5, or greater than about 2.00 g/sec^0.5, or between about 1.60 g/sec^0.5 and about 2.50 g/sec^0.5, or between about 1.65 g/sec^0.5 and about 2.50 g/sec^0.5, or between about 1.70 g/sec^0.5 and about 2.40 g/sec^0.5, or between about 1.75 g/sec^0.5 and about 2.30 g/sec^0.5, or between about 1.80 g/sec^0.5 and about 2.20 g/sec^0.5, or between about 1.82 g/sec^0.5 and about 2.10 g/sec^0.5, or between about 1.85 g/sec^0.5 and about 2.00 g/sec^0.5, specifically reciting all 0.1 g/sec^0.5 increments within the above-recited ranges and all ranges formed therein or thereby.

A Plate Stiffness value of greater than about 8.0 N*mm, or greater than about 12.0 N*mm, or greater than about 12.5 N*mm, or greater than about 13.0 N*mm, or greater than about 13.5 N*mm, or greater than about 14 N*mm, or greater than about 14.5 N*mm, or greater than about 15 N*mm, or greater than about 15.5 N*mm, or greater than about 16 N*mm, or greater than about 16.5 N*mm, or greater than about 17 N*mm, or between about 12 N*mm and about 20 N*mm, or between about 12.5 N*mm and about 20 N*mm, or between about 13 N*mm and about 20 N*mm, or between about 13.5 N*mm and about 20 N*mm, or between about 14 N*mm between about 20 N*mm, or between about 14.5 N*mm and about 20 N*mm, or between about 15 N*mm and about 20 N*mm, or between about 15.5 N*mm and about 20 N*mm, or between about 16 N*mm and about 20 N*mm, or between about 16.5 N*mm and about 20 N*mm, or between about 17 N*mm and about 20 N*mm, specifically reciting all 0.1 N*mm increments within the above-recited ranges and all ranges formed therein or thereby.

A Resilient Bulk value of greater than about 60 cm³/g, or greater than about 85 cm³/g, or greater than about 90 cm³/g, or greater than about 95 cm³/g, or greater than about 100 cm³/g, or greater than about 102 cm³/g, or greater than about 105 cm³/g, or between about 85 cm³/g and about 110 cm³/g, or between about 90 cm³/g and about 110 cm³/g, or between about 95 cm³/g and about 110 cm³/g, or between about 100 cm³/g and about 110 cm³/g, specifically reciting all 1 cm³/g increments within the above-recited ranges and all ranges formed therein or thereby.

A Dry Caliper value of greater than about 26.0 mils, or greater than about 40 mils, or between about 26.0 mils and about 80.0 mils, or between 40.0 mils and 60.0 mils, specifically reciting all 0.10 mil increments within the above-recited ranges and all ranges formed therein or thereby.

A Wet Caliper value of greater than about 17.0 mils, or greater than about 26 mils, or between about 26.0 mils and about 70.0 mils, or between about 26.0 mils and about 40.0 mils, specifically reciting all 0.10 mil increments within the above-recited ranges and all ranges formed therein or thereby.

A Total Dry Tensile (Total Tensile) value of greater than about 1300 g/in, or greater than about 1700 g/in, or between about 1300 g/in and about 4000 g/in, or between about 1800 g/in and about 2800 g/in, specifically reciting all 10 g/in increments within the above-recited ranges and all ranges formed therein or thereby.

A CRT rate value of greater than about 0.30 g/sec, or greater than about 0.61 g/sec, or between about 0.30 g/sec and about 1.00 g/sec, or between about 0.61 g/sec and about 0.85 g/sec, specifically reciting all 0.05 g/sec increments within the above-recited ranges and all ranges formed therein or thereby.

CRT capacity value of greater than about 10.0 g/g, or greater than about 12.5 g/g, or between about 12.5 g/g and about 23.0 g/g, or between about 16.5 g/g and about 21.5 g/g, specifically reciting all 0.1 g/g increments within the above-recited ranges and all ranges formed therein or thereby.

Emtec TS750 value of greater than about 40 dB V² rms, or greater than about 50 dB V² rms, or between about 50 dB V² rms and about 100 dB V² rms, specifically reciting all 10 dB V² rms increments within the above-recited ranges and all ranges formed therein or thereby.

A Dry Compression (value at 1500 g force in mils) of greater than about 15 mils, or greater than about 25 mils, or greater than about 35 mils, or greater than about 45 mils, or greater than about 55 mils, or greater than 65 mils, or between about 15 mils and about 65 mils, or between about 25 mils and about 55 mils, or between about 35 mils and about 45 mils, specifically reciting all 5 mil increments within the above-recited ranges and all ranges formed therein or thereby.

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 23° C.±1.0° C. and a relative humidity of 50%±2% for a minimum of 2 hours prior to the test. The samples tested are “usable units.” “Usable units” as used herein means sheets, flats from roll stock, pre-converted flats, and/or single or multi-ply products. All tests are conducted in such conditioned room. Do not test samples that have defects such as wrinkles, tears, holes, and like. All instruments are calibrated according to manufacturer's specifications.

Basis Weight:

Basis weight of a fibrous structure and/or sanitary tissue product is measured on stacks of twelve usable units using a top loading analytical balance with a resolution of ±0.001 g. The balance is protected from air drafts and other disturbances using a draft shield. A precision cutting die, measuring 3.500 in ±0.0035 in by 3.500 in ±0.0035 in is used to prepare all samples.

With a precision cutting die, cut the samples into squares. Combine the cut squares to form a stack twelve samples thick. Measure the mass of the sample stack and record the result to the nearest 0.001 g.

The Basis Weight is calculated in lbs/3000 ft² or g/m² as follows:

Basis ⁢ Weight = ( Mass ⁢ of ⁢ stack ) / [ ( Area ⁢ of ⁢ 1 ⁢ square ⁢ in ⁢ stack ) × ( No . of ⁢ squares ⁢ in ⁢ stack ) ]

For example:

Basis ⁢ weight ⁢ ( lbs / 3000 ⁢ ft 2 ) = [ [ ⁠ Mass ⁢ of ⁢ stack ⁢ ( g ) / 453.6 ⁢ ( g / lbs ) ] /  [ 12.25 ( in 2 ) / 1 ⁢ 44 ⁢ ( in 2 / ft 2 ) × 12 ] × 3000 or , Basis ⁢ Weight ⁢ ( g / m 2 ) = Mass ⁢ of ⁢ stack ⁢ ( g ) / [ 79.032 ( cm 2 ) / 10 , TagBox[",", "NumberComma", Rule[SyntaxForm, "0"]] 000 ⁢ ( cm 2 / m 2 ) × 12 ] .

Report the numerical result to the nearest 0.1 lbs/3000 ft² or 0.1 g/m² or “gsm.” Sample dimensions can be changed or varied using a similar precision cutter as mentioned above, so as at least 100 square inches of sample area in stack.

Emtec Test Method:

T57 and T5750 values are measured using an EMTEC Tissue Softness Analyzer (“Emtec TSA”) (Emtec Electronic GmbH, Leipzig, Germany) interfaced with a computer running Emtec TSA software (version 3.19 or equivalent). According to Emtec, the T57 value correlates with the real material softness, while the T5750 value correlates with the felt smoothness/roughness of the material. The Emtec TSA comprises a rotor with vertical blades which rotate on the test sample at a defined and calibrated rotational speed (set by manufacturer) and contact force of 100 mN. Contact between the vertical blades and the test piece creates vibrations, which create sound that is recorded by a microphone within the instrument. The recorded sound file is then analyzed by the Emtec TSA software. The sample preparation, instrument operation and testing procedures are performed according the instrument manufacture's specifications.

Sample Preparation

Test samples are prepared by cutting square or circular samples from a finished product. Test samples are cut to a length and width (or diameter if circular) of no less than about 90 mm, and no greater than about 120 mm, in any of these dimensions, to ensure the sample can be clamped into the TSA instrument properly. Test samples are selected to avoid perforations, creases or folds within the testing region. Prepare 8 substantially similar replicate samples for testing. Equilibrate all samples at TAPPI standard temperature and relative humidity conditions (23° C.±2 C.° and 50%±2%) for at least 1 hour prior to conducting the TSA testing, which is also conducted under TAPPI conditions.

Testing Procedure

Calibrate the instrument according to the manufacturer's instructions using the 1-point calibration method with Emtec reference standards (“ref 2 samples”). If these reference samples are no longer available, use the appropriate reference samples provided by the manufacturer. Calibrate the instrument according to the manufacturer's recommendation and instruction, so that the results will be comparable to those obtained when using the 1-point calibration method with Emtec reference standards (“ref. 2 samples”).

Mount the test sample into the instrument and perform the test according to the manufacturer's instructions. When complete, the software displays values for T57 and T5750. Record each of these values to the nearest 0.01 dB V² rms. The test piece is then removed from the instrument and discarded. This testing is performed individually on the top surface (outer facing surface of a rolled product) of four of the replicate samples, and on the bottom surface (inner facing surface of a rolled product) of the other four replicate samples.

The four test result values for TS7 and TS750 from the top surface are averaged (using a simple numerical average); the same is done for the four test result values for TS7 and TS750 from the bottom surface. Report the individual average values of TS7 and TS750 for both the top and bottom surfaces on a particular test sample to the nearest 0.01 dB V² rms. Additionally, average together all eight test value results for TS7 and TS750, and report the overall average values for TS7 and TS750 on a particular test sample to the nearest 0.01 dB V² rms.

Dry Thick Compression and Recovery Test Method (Dry Compression);

Dry Thick Compression and Dry Thick Compressive Recovery are measured using a constant rate of extension tensile tester (a suitable instrument is the EJA Vantage, Thwing-Albert, West Berlin NJ, or equivalent) fitted with compression fixtures, a circular compression foot having an area of 1.0 in² and a circular anvil having an area of at least 4.9 in². The thickness (caliper in mils) is measured at varying pressure values ranging from 10-1500 gun² in both the compression and relaxation directions.

Four (4) samples are prepared by the cutting of a usable unit obtained from the outermost sheets of a finished product roll after removing at least the leading five sheets by unwinding and tearing off via the closest line of weakness, such that each cut sample is 2.5×2.5 inches, avoiding creases, folds, and obvious defects.

The compression foot and anvil surfaces are aligned parallel to each other, and the crosshead zeroed at the point where they are in contact with each other. The tensile tester is programmed to perform a compression cycle, immediately followed by an extension (recovery) cycle. Force and extension data are collected at a rate of 50 Hz, with a crosshead speed of 0.10 in/mm. Force data is converted to pressure (gun², or gsi). The compression cycle continues until a pressure of 1500 gsi is reached, at which point the crosshead stops and immediately begins the extension (recovery) cycle with the data collection and crosshead speed remaining the same.

The sample is placed flat on the anvil fixture, ensuring the sample is centered beneath the foot so that when contact is made the edges of the sample will be avoided. Start the tensile tester and data collection. Testing is repeated in like fashion for all four samples.

The thickness (mils) vs. pressure (g/in², or gsi) data is used to calculate the sample's compressibility, near-zero load caliper, and compressive modulus. A least-squares linear regressions is performed on the thickness vs. the logarithm (baselO) of the applied pressure data using nine discrete data points at pressures of 10, 25, 50, 75, 100, 125, 150, 200, 300 gsi and their respective thickness readings. Compressibility (m) equals the slope of the linear regression line, with units of mils/log (gsi). The higher the magnitude of the negative value the more “compressible” the sample is. Near-zero load caliper (b) equals the y-intercept of the linear regression line, with units of mils. This is the extrapolated thickness at log (1 gsi pressure). Compressive Modulus is calculated as the y-intercept divided by the negative slope (−b/m) with units of log (gsi). Dry Compression at 1500 gsi is the thickness of the sample at 1500 gsi.

Dry Thick Compression is Defined as:

Dry ⁢ Thick ⁢ Compression ⁢ ( mils · mils / log ⁢ ( gsi ) = - 1 ⁢ x ⁢ Near ⁢ Zero ⁢ Load ⁢ Caliper ⁢ ( b ) × Compressiblility ⁢ ( m )

Multiplication by −1 turns formula into a positive. Larger results represent thick products that compress when a pressure is applied. Calculate the arithmetic mean of the four replicate values and report Dry Thick Compression to the nearest integer value mils*mils/log (gsi).

Dry Thick Compressive Recovery is Defined as:

Dry ⁢ Thick ⁢ Compressive ⁢ Recovery ⁢ ( mils ⁢ mils / log ⁢ ( gsi ) = - 1 × Near ⁢ Zero ⁢ Load ⁢ Caliper ⁢ ( b ) × Recovered ⁢ Thickness ⁢ 10 ⁢ gsi ⁢ Compressibility ⁢ ( m ) × Compressed ⁢ Thickness ⁢ at ⁢ 10 ⁢ gsi

Multiplication by −1 turns formula into a positive. Larger results represent thick products that compress when a pressure is applied and maintain fraction recovery at 10 g/in². Compressed thickness at 10 g/in² is the thickness of the material at 10 g/in² pressure during the compressive portion of the test. Recovered thickness at 10 g/in² is the thickness of the material at 10 g/in² pressure during the recovery portion of the test. Calculate the arithmetic mean of the four replicate values and report Dry Thick Compressive Recovery to the nearest integer value mils*mils/log (gsi).

SST Absorbency Rate:

This test incorporates the Slope of the Square Root of Time (SST) Test Method. The SST method measures rate over a wide spectrum of time to capture a view of the product pick-up rate over the useful lifetime. In particular, the method measures the absorbency rate via the slope of the mass versus the square root of time from 2-15 seconds.

Overview

The absorption (wicking) of water by a fibrous sample is measured over time. A sample is placed horizontally in the instrument and is supported with minimal contact during testing (without allowing the sample to droop) by an open weave net structure that rests on a balance. The test is initiated when a tube connected to a water reservoir is raised and the meniscus makes contact with the center of the sample from beneath, at a small negative pressure. Absorption is controlled by the ability of the sample to pull the water from the instrument for approximately 20 seconds. Rate is determined as the slope of the regression line of the outputted weight vs sqrt (time) from 2 to 15 seconds

Apparatus

Conditioned Room—Temperature is controlled from 73° F.±+2° F. (23° C.±1° C.). Relative Humidity is controlled from 50%±2%

Sample Preparation—Product samples are cut using hydraulic/pneumatic precision cutter into 3.375 inch diameter circles.

Capacity Rate Tester (CRT)—The CRT is an absorbency tester capable of measuring capacity and rate. The CRT consists of a balance (0.001 g), on which rests on a woven grid (using nylon monofilament line having a 0.014″ diameter) placed over a small reservoir with a delivery tube in the center. This reservoir is filled by the action of solenoid valves, which help to connect the sample supply reservoir to an intermediate reservoir, the water level of which is monitored by an optical sensor. The CRT is run with a −2 mm water column, controlled by adjusting the height of water in the supply reservoir.

A diagram of the testing apparatus set up is shown in FIG. 14.

Software—Lab View based custom software specific to CRT Version 4.2 or later.

Water—Distilled water with conductivity <10 μS/cm (target <5 μS/cm)@ 25° C.

Sample Preparation

For this method, a usable unit is described as one finished product unit regardless of the number of plies. Condition all samples with packaging materials removed for a minimum of 2 hours prior to testing. Discard at least the first ten usable units from the roll. Remove two usable units and cut one 3.375-inch circular sample from the center of each usable unit for a total of 2 replicates for each test result. Do not test samples with defects such as wrinkles, tears, holes, etc. Replace with another usable unit which is free of such defects

Sample Testing

Pre-Test Set-Up

• • 1. The water height in the reservoir tank is set-2.0 mm below the top of the support rack (where the towel sample will be placed).
  • 2. The supply tube (8 mm I.D.) is centered with respect to the support net.
  • 3. Test samples are cut into circles of 3⅜″ diameter and equilibrated at Tappi environment conditions for a minimum of 2 hours.

Test Description

• • 1. After pressing the start button on the software application, the supply tube moves to 0.33 mm below the water height in the reserve tank. This creates a small meniscus of water above the supply tube to ensure test initiation. A valve between the tank and the supply tube closes, and the scale is zeroed.
  • 2. The software prompts you to “load a sample”. A sample is placed on the support net, centering it over the supply tube, and with the side facing the outside of the roll placed downward.
  • 3. Close the balance windows and press the “OK” button—the software records the dry weight of the circle.
  • 4. The software prompts you to “place cover on sample”. The plastic cover is placed on top of the sample, on top of the support net. The plastic cover has a center pin (which is flush with the outside rim) to ensure that the sample is in the proper position to establish hydraulic connection. Four other pins, 1 mm shorter in depth, are positioned 1.25-1.5 inches radially away from the center pin to ensure the sample is flat during the test. The sample cover rim should not contact the sheet. Close the top balance window and click “OK”.
  • 5. The software re-zeroes the scale and then moves the supply tube towards the sample. When the supply tube reaches its destination, which is 0.33 mm below the support net, the valve opens (i.e., the valve between the reserve tank and the supply tube), and hydraulic connection is established between the supply tube and the sample. Data acquisition occurs at a rate of 5 Hz and is started about 0.4 seconds before water contacts the sample.
  • 6. The test runs for at least 20 seconds. After this, the supply tube pulls away from the sample to break the hydraulic connection.
  • 7. The wet sample is removed from the support net. Residual water on the support net and cover are dried with a paper towel.
  • 8. Repeat until all samples are tested.
  • 9. After each test is run, a *.txt file is created (typically stored in the CRT/data/rate directory) with a file name as typed at the start of the test. The file contains all the test set-up parameters, dry sample weight, and cumulative water absorbed (g) vs. time (sec) data collected from the test.

Calculation of Rate of Uptake

Take the raw data file that includes time and weight data.

First, create a new time column that subtracts 0.4 seconds from the raw time data to adjust the raw time data to correspond to when initiation actually occurs (about 0.4 seconds after data collection begins).

Second, create a column of data that converts the adjusted time data to square root of time data (e.g., using a formula such as SQRT( ) within Excel).

Third, calculate the slope of the weight data vs the square root of time data (e.g., using the SLOPE( ) function within Excel, using the weight data as the y-data and the sqrt (time) data as the x-data, etc.). The slope should be calculated for the data points from 2 to 15 seconds, inclusive (or 1.41 to 3.87 in the sqrt (time) data column).

Calculation of Slope of the Square Root of Time (SST)

The start time of water contact with the sample is estimated to be 0.4 seconds after the start of hydraulic connection is established between the supply tube and the sample (CRT Time). This is because data acquisition begins while the tube is still moving towards the sample and incorporates the small delay in scale response. Thus, “time zero” is actually at 0.4 seconds in CRT Time as recorded in the *.txt file.

The slope of the square root of time (SST) from 2-15 seconds is calculated from the slope of a linear regression line from the square root of time between (and including) 2 to 15 seconds (x-axis) versus the cumulative grams of water absorbed. The units are g/sec^0.5.

Reporting Results

Report the average slope to the nearest 0.01 g/s^0.5.

Plate Stiffness Test Method:

As used herein, the “Plate Stiffness” test is a measure of stiffness of a flat sample as it is deformed downward into a hole beneath the sample. For the test, the sample is modeled as an infinite plate with thickness “t” that resides on a flat surface where it is centered over a hole with radius “R”. A central force “F” applied to the tissue directly over the center of the hole deflects the tissue down into the hole by a distance “w”. For a linear elastic material, the deflection can be predicted by:

w = 3 ⁢ F 4 ⁢ π ⁢ Et 3 ⁢ ( 1 - v ) ⁢ ( 3 + v ) ⁢ R 2

where “E” is the effective linear elastic modulus, “v” is the Poisson's ratio, “R” is the radius of the hole, and “t” is the thickness of the tissue, taken as the caliper in millimeters measured on a stack of 5 tissues under a load of about 0.29 psi. Taking Poisson's ratio as 0.1 (the solution is not highly sensitive to this parameter, so the inaccuracy due to the assumed value is likely to be minor), the previous equation can be rewritten for “w” to estimate the effective modulus as a function of the flexibility test results:

E ≈ 3 ⁢ R 2 4 ⁢ t 3 ⁢ F w

The test results are carried out using an MTS Alliance RT/1, Insight Renew, or similar model testing machine (MTS Systems Corp., Eden Prairie, Minn.), with a 50 newton load cell, and data acquisition rate of at least 25 force points per second. As a stack of five tissue sheets (created without any bending, pressing, or straining) at least 2.5-inches by 2.5 inches, but no more than 5.0 inches by 5.0 inches, oriented in the same direction, sits centered over a hole of radius 15.75 mm on a support plate, a blunt probe of 3.15 mm radius descends at a speed of 20 mm/min. For typical perforated rolled bath tissue, sample preparation consists of removing five (5) connected usable units, and carefully forming a 5 sheet stack, accordion style, by bending only at the perforation lines. When the probe tip descends to 1 mm below the plane of the support plate, the test is terminated. The maximum slope (using least squares regression) in grams of force/mm over any 0.5 mm span during the test is recorded (this maximum slope generally occurs at the end of the stroke). The load cell monitors the applied force and the position of the probe tip relative to the plane of the support plate is also monitored. The peak load is recorded, and “E” is estimated using the above equation.

The Plate Stiffness “S” per unit width can then be calculated as:

S = Et 3 12

and is expressed in units of Newtons*millimeters. The Testworks program uses the following formula to calculate stiffness (or can be calculated manually from the raw data output):

S = ( F w ) [ ( 3 + v ) ⁢ R 2 16 ⁢ π ]

wherein “F/w” is max slope (force divided by deflection), “v” is Poisson's ratio taken as 0.1, and “R” is the ring radius.

The same sample stack (as used above) is then flipped upside down and retested in the same manner as previously described. This test is run three more times (with different sample stacks). Thus, eight S values are calculated from four 5-sheet stacks of the same sample. The numerical average of these eight S values is reported as Plate Stiffness for the sample.

Dry Elongation, Tensile Strength, TEA and Modulus Test Methods:

Remove five (5) strips of four (4) usable units (also referred to as sheets) of fibrous structures and stack one on top of the other to form a long stack with the perforations between the sheets coincident. Identify sheets 1 and 3 for machine direction tensile measurements and sheets 2 and 4 for cross direction tensile measurements. Next, cut through the perforation line using a paper cutter (JDC-1-10 or JDC-1-12 with safety shield from Thwing-Albert Instrument Co. of Philadelphia, Pa.) to make 4 separate stacks. Make sure stacks 1 and 3 are still identified for machine direction testing and stacks 2 and 4 are identified for cross direction testing.

Cut two 1 inch (2.54 cm) wide strips in the machine direction from stacks 1 and 3. Cut two 1 inch (2.54 cm) wide strips in the cross direction from stacks 2 and 4. There are now four 1 inch (2.54 cm) wide strips for machine direction tensile testing and four 1 inch (2.54 cm) wide strips for cross direction tensile testing. For these finished product samples, all eight 1 inch (2.54 cm) wide strips are five usable units (sheets) thick.

For the actual measurement of the elongation, tensile strength, TEA and modulus, use a Thwing-Albert Intelect II Standard Tensile Tester (Thwing-Albert Instrument Co. of Philadelphia, Pa.). Insert the flat face clamps into the unit and calibrate the tester according to the instructions given in the operation manual of the Thwing-Albert Intelect II. Set the instrument crosshead speed to 4.00 in/min (10.16 cm/min) and the 1st and 2nd gauge lengths to 2.00 inches (5.08 cm). The break sensitivity is set to 20.0 grams and the sample width is set to 1.00 inch (2.54 cm) and the sample thickness is set to 0.3937 inch (1 cm). The energy units are set to TEA and the tangent modulus (Modulus) trap setting is set to 38.1 g.

Take one of the fibrous structure sample strips and place one end of it in one clamp of the tensile tester. Place the other end of the fibrous structure sample strip in the other clamp. Make sure the long dimension of the fibrous structure sample strip is running parallel to the sides of the tensile tester. Also make sure the fibrous structure sample strips are not overhanging to the either side of the two clamps. In addition, the pressure of each of the clamps must be in full contact with the fibrous structure sample strip.

After inserting the fibrous structure sample strip into the two clamps, the instrument tension can be monitored. If it shows a value of 5 grams or more, the fibrous structure sample strip is too taut. Conversely, if a period of 2-3 seconds passes after starting the test before any value is recorded, the fibrous structure sample strip is too slack.

Start the tensile tester as described in the tensile tester instrument manual. The test is complete after the crosshead automatically returns to its initial starting position. When the test is complete, read and record the following with units of measure:

• • Peak Load Tensile (Tensile Strength) (g/in)
  • Peak Elongation (Elongation) (%)
  • Peak TEA (TEA) (in-g/in²)
  • Tangent Modulus (Modulus) (at 15 g/cm)

Test each of the samples in the same manner, recording the above measured values from each test.

Calculations:

Geometric ⁢ Mean ⁢ ( GM ) ⁢ Dry ⁢ Elongation = Square ⁢ Root ⁢ of [ MD ⁢ Elongation ⁢ ( % ) × CD ⁢ Elongation ⁢ ( % ) ] Total ⁢ Dry ⁢ Tensile ⁢ ( TDT ) = Peak ⁢ Load ⁢ MD ⁢ Tensile ⁢ ( g / in ) + Peak ⁢ Load ⁢ CD ⁢ Tensile ⁢ ( g / in ) Dry ⁢ Tensile ⁢ Ratio = Peak ⁢ Load ⁢ MD ⁢ Tensile ⁢ ( g / in ) / Peak ⁢ Load ⁢ CD ⁢ Tensile ⁢ ( g / in ) Geometric ⁢ Mean ⁢ ( GM ) ⁢ Dry ⁢ Tensile = 
 [ Square ⁢ Root ⁢ of ⁢ ( Peak ⁢ Load ⁢ MD ⁢ Tensile ⁢ ( g / in ) × 
  Peak ⁢ Load ⁢ CD ⁢ Tensile ⁢ ( g / in ) ) ] Dry ⁢ TEA = MD ⁢ TEA ⁢ ( in - g / in 2 ) + CD ⁢ TEA ⁢ ( in - g / in 2 ) Geometric ⁢ Mean ⁢ ( GM ) ⁢ Dry ⁢ TEA = Square ⁢ Root ⁢ of [ MD ⁢ TEA ⁢ ( in - g / in 2 ) × CD ⁢ TEA ⁢ ( in - g / in 2 ) ] Dry ⁢ Modulus = MD ⁢ Modulus ⁢ ( at ⁢ 15 ⁢ g / cm ) + CD ⁢ Modulus ⁢ ( at ⁢ 15 ⁢ g / cm ) Geometric ⁢ Mean ⁢ ( GM ) ⁢ Dry ⁢ Modulus = Square ⁢ Root ⁢ of [ MD ⁢ Modulus ⁢ ( at ⁢ 15 ⁢ g / cm ) × CD ⁢ Modulus ⁢ ( at ⁢ 15 ⁢ g / cm ) ]

Flexural Rigidity:

This test is performed on 1 inch×6 inch (2.54 cm×15.24 cm) strips of a fibrous structure sample. A Cantilever Bending Tester such as described in ASTM Standard D 1388 (Model 5010, Instrument Marketing Services, Fairfield, NJ) is used and operated at a ramp angle of 41.5±0.5° and a sample slide speed of 0.5±0.2 in/second (1.3±0.5 cm/second). A minimum of n=16 tests are performed on each sample from n=8 sample strips.

No fibrous structure sample which is creased, bent, folded, perforated, or in any other way weakened should ever be tested using this test. A non-creased, non-bent, non-folded, non-perforated, and non-weakened in any other way fibrous structure sample should be used for testing under this test.

From one fibrous structure sample of about 4 inch×6 inch (10.16 cm×15.24 cm), carefully cut using a 1 inch (2.54 cm) JDC Cutter (available from Thwing-Albert Instrument Company, Philadelphia, PA) four (4) 1 inch (2.54 cm) wide by 6 inch (15.24 cm) long strips of the fibrous structure in the MD direction. From a second fibrous structure sample from the same sample set, carefully cut four (4) 1 inch (2.54 cm) wide by 6 inch (15.24 cm) long strips of the fibrous structure in the CD direction. It is important that the cut be exactly perpendicular to the long dimension of the strip. In cutting non-laminated two-ply fibrous structure strips, the strips should be cut individually. The strip should also be free of wrinkles or excessive mechanical manipulation which can impact flexibility. Mark the direction very lightly on one end of the strip, keeping the same surface of the sample up for all strips. Later, the strips will be turned over for testing, thus it is important that one surface of the strip be clearly identified, however, it makes no difference which surface of the sample is designated as the upper surface.

Using other portions of the fibrous structure (not the cut strips), determine the basis weight of the fibrous structure sample in lbs/3000 ft² and the caliper of the fibrous structure in mils (thousandths of an inch) using the standard procedures disclosed herein. Place the Cantilever Bending Tester level on a bench or table that is relatively free of vibration, excessive heat and most importantly air drafts. Adjust the platform of the Tester to horizontal as indicated by the leveling bubble and verify that the ramp angle is at 41.5±0.5°. Remove the sample slide bar from the top of the platform of the Tester. Place one of the strips on the horizontal platform using care to align the strip parallel with the movable sample slide. Align the strip exactly even with the vertical edge of the Tester wherein the angular ramp is attached or where the zero mark line is scribed on the Tester. Carefully place the sample slide bar back on top of the sample strip in the Tester. The sample slide bar must be carefully placed so that the strip is not wrinkled or moved from its initial position.

Move the strip and movable sample slide at a rate of approximately 0.5±0.2 in/second (1.3±0.5 cm/second) toward the end of the Tester to which the angular ramp is attached. This can be accomplished with either a manual or automatic Tester. Ensure that no slippage between the strip and movable sample slide occurs. As the sample slide bar and strip project over the edge of the Tester, the strip will begin to bend, or drape downward. Stop moving the sample slide bar the instant the leading edge of the strip falls level with the ramp edge. Read and record the overhang length from the linear scale to the nearest 0.5 mm. Record the distance the sample slide bar has moved in cm as overhang length. This test sequence is performed a total of eight (8) times for each fibrous structure in each direction (MD and CD). The first four strips are tested with the upper surface as the fibrous structure was cut facing up. The last four strips are inverted so that the upper surface as the fibrous structure was cut is facing down as the strip is placed on the horizontal platform of the Tester.

The average overhang length is determined by averaging the sixteen (16) readings obtained on a fibrous structure.

Overhang ⁢ Length ⁢ MD = Sum ⁢ of ⁢ 8 ⁢ MD ⁢ readings 8 Overhang ⁢ Length ⁢ CD = Sum ⁢ of ⁢ 8 ⁢ CD ⁢ readings 8 Bend ⁢ Length ⁢ MD = Overhang ⁢ Length ⁢ MD 2 Bend ⁢ Length ⁢ CD = Overhang ⁢ Length ⁢ CD 2 Bend ⁢ Length ⁢ Total = Overhang ⁢ Length ⁢ Total 2 Flexural ⁢ Rigidity = 0.1629 × W × C 3

wherein W is the basis weight of the fibrous structure in lbs/3000 ft²; C is the bending length (MD or CD or Total) in cm; and the constant 0.1629 is used to convert the basis weight from English to metric units. The results are expressed in mg-cm.

GM ⁢ Flexural ⁢ Rigidity = Square ⁢ root ⁢ of ⁢ ( MD ⁢ Flexural ⁢ Rigidity × CD ⁢ Flexural ⁢ Rigidity )

CRT Rate and Capacity

CRT Rate and Capacity values are generated by running the test procedure as defined in U.S. Patent Application No. US 2017-0183824.

Dry and Wet Caliper Test Methods

Dry and Wet Caliper values are generated by running the test procedure as defined in U.S. Pat. No. 7,744,723 and states, in relevant part:

Dry Caliper

Samples are conditioned at 23+/−1° C. and 50%+/−2% relative humidity for two hours prior to testing.

Dry Caliper of a sample of fibrous structure product is determined by cutting a sample of the fibrous structure product such that it is larger in size than a load foot loading surface where the load foot loading surface has a circular surface area of about 3.14 in 2. 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 14.7 g/cm² (about 0.21 psi). The caliper is the resulting gap between the flat surface and the load foot loading surface. Such measurements can be obtained on a VIR Electronic Thickness Tester Model II available from Thwing-Albert Instrument Company, Philadelphia, Pa. The caliper measurement is repeated and recorded at least five (5) times so that an average caliper can be calculated. The result is reported in mils.

Wet Caliper

Samples are conditioned at 23+/−1° C. and 50% relative humidity for two hours prior to testing.

Wet Caliper of a sample of fibrous structure product is determined by cutting a sample of the fibrous structure product such that it is larger in size than a load foot loading surface where the load foot loading surface has a circular surface area of about 3.14 in². Each sample is wetted by submerging the sample in a distilled water bath for 30 seconds. The caliper of the wet sample is measured within 30 seconds of removing the sample from the bath. The sample is then 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 14.7 g/cm² (about 0.21 psi). The caliper is the resulting gap between the flat surface and the load foot loading surface. Such measurements can be obtained on a VIR Electronic Thickness Tester Model II available from Thwing-Albert Instrument Company, Philadelphia, Pa. The caliper measurement is repeated and recorded at least five (5) times so that an average caliper can be calculated. The result is reported in mils.

Micro-CT Intensive Property Measurement Method:

The micro-CT intensive property measurement method measures the basis weight, thickness and density values within visually discernable zones or regions of a substrate sample. It is based on analysis of a 3D x-ray sample image obtained on a micro-CT instrument (a suitable instrument is the Scanco μCT 50 available from Scanco Medical AG, Switzerland, or equivalent). The micro-CT instrument is a cone beam microtomograph with a shielded cabinet. A maintenance free x-ray tube is used as the source with an adjustable diameter focal spot. The x-ray beam passes through the sample, where some of the x-rays are attenuated by the sample. The extent of attenuation correlates to the mass of material the x-rays have to pass through. The transmitted x-rays continue on to the digital detector array and generate a 2D projection image of the sample. A 3D image of the sample is generated by collecting several individual projection images of the sample as it is rotated, which are then reconstructed into a single 3D image. The instrument is interfaced with a computer running software to control the image acquisition and save the raw data. The 3D image is then analyzed using image analysis software (a suitable image analysis software is MATLAB available from The Mathworks, Inc., Natick, MA, or equivalent) to measure the basis weight, thickness and density intensive properties of regions within the sample.

Sample Preparation

To obtain a sample for measurement, lay a single layer of the dry substrate material out flat and die cut a circular piece with a diameter of 16 mm. If the sample being measured is a 2 (or more) ply finished product, carefully separate an individual ply of the finished product prior to die cutting. The sample weight is recorded. A sample may be cut from any location containing the region or cells to be analyzed. Regions, zones, or cells within different samples taken from the same substrate material can be analyzed and compared to each other. Care should be taken to avoid embossed regions, folds, wrinkles, or tears when selecting a location for sampling.

Image Acquisition

Set up and calibrate the micro-CT instrument according to the manufacturer's specifications. Place the sample into the appropriate holder, between two rings of low-density material, which have an inner diameter of 12 mm. This will allow the central portion of the sample to lay horizontal and be scanned without having any other materials directly adjacent to its upper and lower surfaces. Measurements should be taken in this region. The 3D image field of view is approximately 20 mm on each side in the xy-plane with a resolution of approximately 3400 by 3400 pixels, and with a sufficient number of 6 micron thick slices collected to fully include the z-direction of the sample. The reconstructed 3D image contains isotropic voxels of 6 microns. Images were acquired with the source at 45 kVp and 133 μA with no additional low energy filter. These current and voltage settings should be optimized to produce the maximum contrast in the projection data with sufficient x-ray penetration through the sample, but once optimized held constant for all substantially similar samples. A total of 1700 projections images are obtained with an integration time of 500 ms and 4 averages. The projection images are reconstructed into the 3D image and saved in 16-bit format to preserve the full detector output signal for analysis.

Image Processing

Load the 3D image into the image analysis software. The largest cross-sectional area of the sample should be nearly parallel with the x-y plane, with the z-axis being perpendicular. Threshold the 3D image at a value which separates, and removes, the background signal due to air, but maintains the signal from the sample fibers within the substrate.

Five 2D intensive property images are generated from the thresholded 3D image. The first is the Basis Weight Image, which is a projection image. Each x-y pixel in this image represents the summation of the intensity values along voxels in the z-direction. This results in a 2D image where each pixel now has a value equal to the cumulative signal through the entire sample.

The weight of the sample divided by the z-direction projected area of the punched sample provides the actual average basis weight of the sample. This correlates with the average signal intensity from the Basis Weight image described above, allowing it to be represented in units of g/m² (gsm).

The second intensive property 2D image is the Thickness Image. To generate this image the upper and lower surfaces of the sample are identified, and the distance between these surfaces is calculated giving the sample thickness. The upper surface of the sample is identified by starting at the uppermost z-direction slice and evaluating each slice going through the sample to locate the z-direction voxel for all pixel positions in the xy-plane where sample signal was first detected. The same procedure is followed for identifying the lower surface of the sample, except the z-direction voxels located are all the positions in the xy-plane where sample signal was last detected. Once the upper and lower surfaces have been identified they are smoothed with a 15×15 median filter to remove signal from stray fibers. The 2D Thickness Image is then generated by counting the number of voxels that exist between the upper and lower surfaces for each of the pixel positions in the xy-plane. This raw thickness value is then converted to actual distance, in microns, by multiplying the voxel count by the 6 μm slice thickness resolution.

The third intensive property 2D image is the Density Image (see for example FIG. 12). To generate this image, divide each xy-plane pixel value in the Basis Weight Image, in units of gsm, by the corresponding pixel in the Thickness Image, in units of microns. The units of the Density Image are grams per cubic centimeter (g/cc).

For each x-y location, the first and last occurrence of a thresholded voxel position in the z-direction is recorded. This provides two sets of points representing the Top Layer and Bottom

Layer of the sample. Each set of points are fit to a second-order polynomial to provide smooth top and bottom surfaces. These surfaces define fourth and fifth 2D intensive property images, the top-layer and bottom-layer of the sample. These surfaces are saved as images with the gray values of each pixel representing the z-value of the surface point.

Micro-CT Basis Weight. Thickness and Density Intensive Properties

This sub-section of the method may be used to measure zones or regions generally. Begin by identifying the zone or region to be analyzed. Next, identify the boundary of the identified region to be analyzed. The boundary of a region is identified by visual discernment of differences in intensive properties when compared to other regions within the sample. For example, a region boundary can be identified based by visually discerning a thickness difference when compared to another region in the sample. Any of the intensive properties can be used to discern region boundaries on either on the physical sample itself or any of the micro-CT intensive property images. Once the boundary of a zone or region has been identified draw the largest circular region of interest that can be inscribed within the region. From each of the first three intensive property images calculate the average basis weight, thickness, and density within the region of interest. Record these values as the region's micro-CT basis weight to the nearest 0.01 gsm, micro-CT thickness to the nearest 0.1 micron and micro-CT density to the nearest 0.0001 g/cc.

To calculate the percent difference between zones or regions may be calculated according to the “Percent (%) difference” definition above.

Concavity Ratio and Packing Fraction Measurements

As outlined above, five different types of 2D intensive property images are created. These images include: (1) a basis weight image, (2) a thickness image, (3) a density image, (4) a top-layer image, and (5) a bottom-layer image.

To measure discrete pillow and knuckle Concavity Ratio and Packing Fraction, begin by identifying the boundary of the selected discrete pillow or knuckle cells. The boundary of a cell is identified by visual discernment of differences in intensive properties when compared to other cells within the sample. For example, a cell boundary can be identified based by visually discerning a density difference when compared to another cell in the sample. Any of the intensive properties (basis weight, thickness, density, top-layer, and bottom-layer) can be used to discern cell boundaries on either the physical sample itself or any of the micro-CT 2D intensive property images.

Using the image analysis software, manually draw a line tracing the identified boundary of each individual whole and partial discrete knuckle or discrete pillow cell 1000 visible within the sample boundary 2400, and generate a new binary image containing only the closed filled in shapes of all the identified discrete cells (see for example FIG. 46). Analyze all the individual discrete cell shapes in the binary image and record the following measurements for each: 1) Area and 2) Convex Hull Area.

The Concavity Ratio is a measure of the presence and extent of concavity within the shapes of the discrete knuckle or pillow cells. Using the recorded measurements calculate the Concavity Ratio for each of the analyzed discrete cells as the ratio of the shape area to its convex hull area. Identify ten substantially similar replicate discrete knuckle or pillow cells and average together their individual Concavity Ratio values and report the average Concavity Ratio as a unitless value to the nearest 0.01. If ten replicate cells cannot be identified in a single sample, then a sufficient number of replicate samples are to be analyzed according to the described procedure. If the sample contains discrete knuckle or pillow cells of differing size or shape, identify ten substantially similar replicates of each of the different shapes and sizes, calculate an average Concavity Ratio for each and report the minimum average Concavity Ratio value.

The Packing Fraction is the fraction of the sample area filled by the discrete knuckle and pillow shapes. The Packing Fraction value for the sample is calculated by summing all the recorded whole and partial identified shape areas, regardless of shape or size, and dividing that total by the sample area within the sample boundary 1000. The Packing Fraction is reported as a unitless value to the nearest 0.01.

Aspects of the Disclosure

Various aspects relate to:

1. A structure selected from the group consisting of a fibrous structure, a papermaking belt, a structuring layer, and a mask, the structure comprising: a plurality of cell clusters, wherein at least some of the plurality of cell clusters define a first para-cluster channel therebetween; wherein at least a pair of the plurality of cell clusters define a wedge-shaped cross channel therebetween; wherein the wedge-shaped cross channel comprises a narrow portion and a wide portion; wherein the narrow portion of the wedge-shaped support is supportively-adjacent to the first para-cluster channel.

2 The structure of paragraph 1, wherein each cell cluster comprises a plurality of cells; wherein each cell in each cell cluster comprises a non-center-facing side and a center-facing side; wherein the center-facing side of each cell in each cell cluster faces a centroid of the cell cluster; wherein the non-center-facing side of each cell in each cell cluster defines a portion of a perimeter of the cell cluster.

3. The structure of any of paragraph 1 or 2, wherein the first para-cluster channel has a width of from greater than about 55 mils to about 500 mils.

4. The structure of any of paragraphs 1 to 3, wherein at least some of the plurality of cell clusters define a second para-cluster channel therebetween, and wherein a spacing between the first para-cluster channel and the second para-cluster channel from greater than about 100 mils to about 1000 mils.

5. The structure of any of paragraphs 1 to 4, wherein at least one cell cluster of the plurality of cell clusters comprises an intra-cluster channel.

6. The structure of paragraph 5, wherein the intra-cluster channel is substantially perpendicular to at least a portion of the first para-cluster channel.

7. The structure of paragraph 6, wherein the intra-cluster channel is supportively-adjacent to the first para-cluster channel.

8. The structure of any of paragraphs 1 to 7, wherein at least a pair of the plurality of cell clusters comprise intra-cluster channels.

9. The structure of paragraph 8, wherein the intra-cluster channels align to form an inter-cluster channel.

10. The structure of paragraph 9, wherein the inter-cluster channel is substantially parallel to the first para-cluster channel.

11. The structure of paragraph 10, wherein the para-cluster channel has a first width, wherein the inter-cluster channel has a second width, and wherein a ratio of the first width to the second width is greater than about 1.25.

12. The structure of paragraph 11, wherein the ratio is from about 1.25 to about 5.

13. A structure selected from the group consisting of a fibrous structure, a papermaking belt, a structuring layer, and a mask, the structure comprising: a plurality of cell clusters, wherein at least some of the plurality of cell clusters define a first para-cluster channel therebetween; wherein the first para-cluster channel has a first side and a second side; wherein a first cell cluster on the first side of the first para-cluster channel comprises a first intra-cluster channel that is substantially perpendicular to and supportively-adjacent to a portion of the first para-cluster channel; wherein a second cell cluster on the second side of the first para-cluster channel comprises a second intra-cluster channel that is substantially perpendicular to and supportively-adjacent to the portion of the first para-cluster channel; wherein the first intra-cluster channel and the second intra-cluster channel are not aligned.

14. The structure of paragraph 13, wherein each cell cluster comprises a plurality of cells; wherein each cell in each cell cluster comprises a non-center-facing side and a center-facing side; wherein the center-facing side of each cell in each cell cluster faces a centroid of the cell cluster; wherein the non-center-facing side of each cell in each cell cluster defines a portion of a perimeter of the cell cluster.

15 The structure of paragraph 13 or 14, wherein the first para-cluster channel has a width of from greater than about 55 mils to about 500 mils.

16. The structure of any of paragraphs 13 to 15, wherein at least some of the plurality of cell clusters define a second para-cluster channel therebetween, and wherein a spacing between the first para-cluster channel and the second para-cluster channel from greater than about 100 mils to about 1000 mils.

17. The structure of any of paragraphs 13 to 16, wherein at least a pair of the plurality of cell clusters comprise intra-cluster channels.

18. The structure of paragraph 17, wherein the intra-cluster channels align to form an inter-cluster channel.

19. The structure of paragraph 18, wherein the inter-cluster channel is substantially parallel to the first para-cluster channel.

20. The structure of paragraph 19, wherein the first para-cluster channel has a first width, wherein the inter-cluster channel has a second width, and wherein a ratio of the first width to the second width is greater than about 1.25.

21. The structure of paragraph 20, wherein the ratio is from about 1.25 to about 5.

22. A structure selected from the group consisting of a fibrous structure, a papermaking belt, a structuring layer, and a mask, the structure comprising: a plurality of cell clusters, wherein at least some of the plurality of cell clusters define a first para-cluster channel therebetween; wherein the first para-cluster channel has a first side and a second side; wherein a first cell cluster on the first side of the first para-cluster channel comprises a first intra-cluster channel that is substantially perpendicular to and supportively-adjacent to a portion of the first para-cluster channel; wherein a second cell cluster on the second side of the first para-cluster channel comprises a second intra-cluster channel that is substantially perpendicular to and supportively-adjacent to the portion of the first para-cluster channel; wherein the cells of the first cell cluster are not aligned with the cells of the second cell cluster.

23. The structure of paragraph 22, wherein each cell cluster comprises a plurality of cells; wherein each cell in each cell cluster comprises a non-center-facing side and a center-facing side; wherein the center-facing side of each cell in each cell cluster faces a centroid of the cell cluster; wherein the non-center-facing side of each cell in each cell cluster defines a portion of a perimeter of the cell cluster;

24. The structure of paragraph 22 or 23, wherein the first para-cluster channel has a width of from greater than about 55 mils to about 500 mils.

25. The structure of any of paragraphs 22 to 24, wherein at least some of the plurality of cell clusters define a second para-cluster channel therebetween, and wherein a spacing between the first para-cluster channel and the second para-cluster channel from greater than about 100 mils to about 1000 mils.

26. The structure of any of paragraphs 22 to 25, wherein at least a pair of the plurality of cell clusters comprise intra-cluster channels.

27. The structure of paragraph 26, wherein the intra-cluster channels align to form an inter-cluster channel.

28. The structure of paragraph 27, wherein the inter-cluster channel is substantially parallel to the first para-cluster channel.

29. The structure of paragraph 28, wherein the first para-cluster channel has a first width, wherein the inter-cluster channel has a second width, and wherein a ratio of the first width to the second width is greater than about 1.25.

30. The structure of paragraph 29, wherein the ratio is from about 1.25 to about 5.

31. A structure selected from the group consisting of a fibrous structure, a papermaking belt, a structuring layer, and a mask, the structure comprising: at least one cell cluster in which, the cell cluster comprises a plurality of cells; at least one cell comprises a non-center-facing side and a center-facing side; wherein the center-facing side faces a centroid of the cell cluster; wherein the non-center-facing side defines a portion of a perimeter of the cell cluster; wherein the at least one cell exhibits a concavity ratio of about 0.8 to 1; and wherein the center-facing sides of the cells in the cell cluster bound a supported area having an area of from greater than about 1.9 mm² to about 10 mm².

32. The structure of paragraph 31, wherein the width of each cell cluster in the at least one cell cluster is from greater than about 2 mm to about 10 mm; and wherein the length of each cell cluster is from greater than about 2 mm to about 10 mm.

33. The structure of paragraph 31 or 32, wherein each cell in the at least one cell cluster has substantially the same size and shape.

34. The structure of any of paragraphs 31 to 33, wherein each cell in the at least one cell cluster is equally spaced from the centroid of the cell cluster.

35. The structure of any of paragraphs 31 to 34, wherein the non-center-facing side comprises one or more selected from the group consisting of a straight segment, a curved segment, and combinations thereof.

36. The structure of any of paragraphs 31 to 35, wherein the center-facing side comprises one or more selected from the group consisting of a straight segment, a curved segment, and combinations thereof.

37. The structure of any of paragraphs 31 to 36, wherein the non-center-facing side has a length of from about 41 mils to about 100 mils.

38. The structure of any of paragraphs 31 to 37, wherein the center-facing side has a length of from about 10 mils to about 40 mils.

39. The structure of any of paragraphs 31 to 38, wherein the supported area has an aspect ratio of from about 1:1 to about 1:8.

40. The structure of any of paragraphs 31 to 39, wherein the supported area has a shape selected from the group consisting of a n-sided polygon, a circle, and an oval, wherein n is from 3 to 30.

41. The structure of any of paragraphs 31 to 40, wherein the supported area has a shape selected from the group consisting of a n-sided polygon, a circle, and an oval, wherein n is from 3 to 30.

42. The structure of any of paragraphs 31 to 41, wherein the perimeter of the cell cluster has a shape selected from the group consisting of a n-sided polygon, a circle, and an oval, wherein n is from 3 to 30.

43. The structure of any of paragraphs 31 to 42, wherein the perimeter of the cell cluster is an n-sided polygon, having radiused corners, wherein n is from 3 to 30.

44. The structure of any of paragraphs 31 to 43, wherein the supported central area is at least about 5% of the total area of the structure.

45. The structure of any of paragraphs 1 to 44, wherein the fibrous structure has a dry-to-wet caliper ratio less than about 1.4.

46. The structure of any of paragraphs 1 to 44, wherein the fibrous structure has a dry-to-wet caliper ratio less than about 1.35.

47. The structure of any of paragraphs 1 to 44, wherein the fibrous structure has a dry-to-wet caliper ratio less than about 1.3.

48. The structure of any of paragraphs 1 to 47, wherein the fibrous structure has a basis weight greater than about 37.5 lbs/3000 ft².

49. The structure of any of paragraphs 1 to 47, wherein the fibrous structure has a basis weight greater than about 38.0 lbs/3000 ft².

50. The structure of any of paragraphs 1 to 47, wherein the fibrous structure has a basis weight greater than about 38.5 lbs/3000 ft².

Examples

The following examples are put forth to provide those of ordinary skill in the art with a complete disclosure and description of how to perform the methods, how to make, and how to use the compositions and compounds disclosed and claimed herein. Efforts have been made to ensure accuracy with respect to numbers (e.g., amounts, temperature, etc.), but some errors and deviations should be accounted for. The purpose of the following examples is not to limit the scope of the various embodiments, but merely to provide examples illustrating specific embodiments.

Further nonlimiting examples of the new fibrous structures as detailed herein may have the properties as disclosed in the Table 1, shown in FIG. 46. Inventive Examples A, B, C, D, and E were made using the exemplary cell pattern as shown in FIG. 43 with a Supported Central Area of about 1.9-2.9 mm{circumflex over ( )}2, a cell cluster perimeter of about 12-16 mm, a para-cluster channel width of about 55-70 mils and an individual cell concavity ratio of 0.8-1.

Beyond the other advantages described for embodiments of the present disclosure, in order to improve perceived hand feel, it may be desirable for the fibrous structures detailed herein to have dry-to-wet caliper ratios less than about 1.4, 1.35, or 1.3, which may be combined with basis weights greater than about 37.5 lbs/3000 ft², 38 lbs/3000 ft², or 38.5 lbs/3000 ft². Particularly referencing Inventive Examples D and E, their characteristics may be accomplished, in part, by increasing forming wire speeds (greater than about 10%, 15%, or 20% versus Inventive Examples A-C) and/or by increased calendaring. Inventive Examples D and E may be perceived as thicker (which can contribute to improved hand feel) due, in part, to the combination of their dry-to-wet ratios, basis weights, and belt patterns.

Comparative Market samples were commercially obtained and tested as detailed herein and have the testing parameters outlined in Table 2, shown in FIG. 47.

Further Definitions and Cross-References

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 disclosure have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications may 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.