Lotioned Fibrous Structures and Methods for Making Same

The present invention relates to fibrous structures, more particularly to fibrous structures having a surface comprising a novel surface pattern comprising a continuous knuckle region and a plurality of discrete pillow regions such that the fibrous structures and/or sanitary tissue products comprising such fibrous structures, for example bath tissue products, exhibit improved lotion properties, such as lotion transfer to increase the amount of lotion delivered to a user's skin and to provide better skin health, compared to known fibrous structures and/or sanitary tissue products comprising such known fibrous structures, and better sheet control during the making of such fibrous structures, methods for making same, and molding members, for example patterned molding members, such as patterned resin-containing belts, used in such methods.

Certain consumers of fibrous structures, for example sanitary tissue products, such as bath tissue products, continue to desire improved lotion transfer from their fibrous structures. Previous attempts to deliver improve lotion transfer from fibrous structures, for example sanitary tissue products, such as bath tissue products, have employed fibrous structures that have a surface comprising a surface pattern comprising a continuous pillow and discrete knuckles. Examples of such prior art fibrous structures are shown in Prior Art.

As shown in Prior Art, one prior art fibrous structure, which was “fabric side out” (“FSO”), comprises a surface pattern on its surfacecomprising a continuous knuckle region, which is represented by the black (darker) continuous network, imparted by the continuous knuckle network, which is represented by the white continuous network of Prior Art. Discrete pillow regions, which are represented by the white regions in Prior Art, are dispersed within the continuous knuckle regionas shown in Prior Art. The discrete pillow regionsare imparted by the discrete pillows, represented by the black regions of the molding memberof Prior Art. The discrete pillowscomprise deflection conduitsinto which portions of a prior art fibrous structure ply being made on the molding memberdeflect. As shown in Prior Art, in one example, the molding membercomprises a reinforcing elementupon which a continuous knuckle networkformed by a continuous network of resinthat defines a non-random, repeating pattern of discrete pillowsnot groups of discrete pillows. The prior art fibrous structuremade on such a molding memberof Prior Artwould exhibit sheet control negatives including necking (narrowing of the sheet width during papermaking of the prior art fibrous structure.

Accordingly, the problem faced by formulators is how to make a fibrous structure that exhibits improved lotion transfer and better sheet control and/or less necking (more sheet width stability and/or less sheet width narrowing) compared to known fibrous structures.

Accordingly, there exists a need for a fibrous structure that exhibits improved lotion transfer and better sheet control during papermaking of the fibrous structure than known fibrous structures and/or sanitary tissue products comprising such fibrous structures, for example bath tissue products, methods for making same, and molding members used in such methods.

The present invention fulfills the need described above by providing fibrous structures, for example sanitary tissue products, such as bath tissue products, that exhibit improved lotion transfer compared to known prior art fibrous structures and/or sanitary tissue products comprising such known prior art fibrous structures, and/or better sheet control, including less necking (less or no narrowing of the fibrous structure's width in the CD during the making of such fibrous structures), methods for making same, and molding members, for example patterned molding members, such as patterned resin-containing belts, used in such methods to impart a surface pattern of a continuous knuckle region and a plurality of discrete pillow regions to a surface of the fibrous structures.

One solution to the problem set forth above is achieved by making the fibrous structures, for example sanitary tissue products or at least one fibrous structure ply employed in the sanitary tissue products on molding members, for example patterned molding members that impart a surface pattern, for example a three-dimensional (3D) pattern to surfaces of the fibrous structures and/or sanitary tissue products and/or fibrous structure plies made thereon, wherein the molding members are designed such that the resulting fibrous structures and/or sanitary tissue products, for example bath tissue products, made using the molding members provide improved lotion transfer than known prior art fibrous structures, for example known prior art sanitary tissue products. In order to achieve the benefits of the fibrous structures of the present invention, one or more of the following properties/characteristics need to be present in the surface pattern: 1) the surface pattern comprises a continuous knuckle region and a plurality of discrete pillow regions dispersed within the continuous knuckle region; 2) the surface pattern comprises a repeat unit defined by two or more groups of two or more discrete pillow regions; 3) the surface pattern comprises at least two groups of two or more discrete pillow regions that are non-parallelly juxtaposed; 4) the surface pattern comprises two or more discrete pillow regions that are non-parallelly juxtaposed; 5) the surface pattern comprises at least two discrete pillow regions that are non-parallelly juxtaposed, especially when the at least two discrete pillow regions are present in different groups of two or more discrete pillow regions; 6) the surface pattern comprises at least one and/or a plurality and/or all discrete pillow region(s) wherein an individual discrete pillow region exhibits a discrete pillow region length of greater than 2 mm as measured according to the Micro-CT Intensive Property Measurement Test Method described herein; 7) the surface pattern comprises at least one and/or a plurality and/or all discrete pillow region(s) wherein an individual discrete pillow region exhibits a discrete pillow region length to discrete pillow region width ratio of greater than 1.3 as measured according to the Micro-CT Intensive Property Measurement Test Method described herein; 8) the surface pattern comprises at least one and/or a plurality and/or all discrete pillow region(s) wherein an individual discrete pillow region exhibits a perimeter of greater than 5 mm as measured according to the Micro-CT Intensive Property Measurement Test Method described herein; 9) the surface pattern comprises at least one and/or a plurality and/or all discrete pillow region(s) wherein an individual discrete pillow region exhibits a discrete pillow region perimeter to average knuckle region width of greater than 21 as measured according to the Micro-CT Intensive Property Measurement Test Method described herein; 10) the surface pattern comprises at least one and/or a plurality and/or all discrete pillow region(s) wherein an individual discrete pillow region exhibits a discrete pillow region length to average knuckle region width of greater than 6.5 as measured according to the Micro-CT Intensive Property Measurement Test Method described herein; 11) the surface pattern comprising a continuous knuckle region and a plurality of discrete pillow regions such that the fibrous structure is void of nubs; 12) the surface pattern comprises a continuous knuckle region that exhibits a substantially uniform knuckle region width, for example the knuckle region width of the continuous knuckle region exhibits a relative standard deviation of less than 25% as measured according to the Micro-CT Intensive Property Measurement Test Method described herein; 13) the surface pattern comprises at least one and/or a plurality and/or all discrete pillow region(s) wherein an individual discrete pillow region exhibits a substantially uniform discrete pillow region width, for example the discrete pillow region width of the discrete pillow region exhibits a relative standard deviation of less than 25% as measured according to the Micro-CT Intensive Property Measurement Test Method described herein; 14) the surface pattern comprises minimal and/or no discrete pillow regions having a shape that includes a curvature, especially if the discrete pillow region(s) are oriented in two or more different directions in the x-y plane of the surface of the fibrous structure; and 15) the surface pattern exhibits multi-axiality, for example biaxiality, in other words the surface pattern is a biaxial surface pattern, for example based on the discrete pillow regions and/or the groups of two or more discrete pillow regions.

Non-limiting examples of such molding members for use in the present invention include patterned felts, patterned forming wires, patterned rolls, patterned fabrics, and patterned belts utilized in conventional wet-pressed papermaking processes, air-laid papermaking processes, and/or wet-laid papermaking processes that produce surface patterned, for example 3D patterned fibrous structures and/or 3D patterned sanitary tissue products and/or 3D patterned fibrous structure plies employed in sanitary tissue products. Other non-limiting examples of such molding members include through-air-drying fabrics and through-air-drying belts utilized in through-air-drying papermaking processes that produce through-air-dried fibrous structures and/or sanitary tissue products, for example 3D patterned through-air dried fibrous structures and/or 3D patterned through-air-dried sanitary tissue products and/or 3D patterned through-air-dried fibrous structure plies employed in sanitary tissue products.

In one example of the present invention, a fibrous structure, for example a sanitary tissue product, comprising a plurality of fibrous elements and a lotion present on at least one surface of the fibrous structure such that the fibrous structure falls above a line having the following equation y=2.8202x graphed on a plot of Lotion Add-on Level (lbs/3000 ft) to Lotion Transfer (μg/cm) where the x-axis is Lotion Add-on Level (lbs/3000 ft) and the y-axis is Lotion Transfer (μg/cm) is provided.

In another example of the present invention, a fibrous structure, for example a sanitary tissue product, comprising a plurality of fibrous elements and a lotion present on at least one surface of the fibrous structure such that the fibrous exhibits a lotion transfer of greater than 7.4 and/or greater than 7.6 and/or greater than 7.8 and/or greater than 8.0 and/or greater than 8.5 and/or greater than 9.0 and/or greater than 9.4 and/or greater than 10.0 and/or greater than 10.5 and/or greater than 11.0 and/or greater than 11.1 and/or greater than 7.4 to 15.0 and/or greater than 7.6 to 15.0 and/or greater than 8.0 to 13.0 and/or greater than 9.0 to 11.0 ug/cmas measured according to the Lotion Transfer Test Method is provided.

In another example of the present invention, a fibrous structure, for example a sanitary tissue product, comprising a plurality of fibrous elements and a lotion present on at least one surface of the fibrous structure such that the fibrous structure falls above a line having the following equation y=0.0163x graphed on a plot of Lotion on Sheet (ug/cm) to Lotion Transfer (μg/cm) where the x-axis is Lotion on Sheet (μg/cm) and the y-axis is Lotion Transfer (μg/cm) is provided.

In another example of the present invention, a method for making a fibrous structure according to the present invention, wherein the method comprises the step of contacting a molding member with a fibrous structure comprising a plurality of pulp fibers such that a surface pattern is imparted to the fibrous structure to form a patterned, for example 3D patterned, fibrous structure ply, which can then form or be incorporated into a single-or multi-ply sanitary tissue product, for example a single- or multi-ply bath tissue product is provided.

In another example of the present invention, a molding member, for example a patterned molding member, such as a through-air-drying fabric, comprising a pattern that is capable of imparting a surface pattern according to the present invention to a fibrous structure during a fibrous structure making process, for example a papermaking process is provided.

It has been found that the orientation of the fibrous structure, specifically converting the fibrous structure such that its uncreped surface (the surface that has not contacted the dryer and/or Yankee and thus has not been creped off the dryer and/or Yankee) (low density discrete pillow region side out (“FSO”) thus forming the consumer contacting surface rather than the high density continuous knuckle region side out (wire side out “WSO”) improves surface mobility. Not wishing to be bound by theory, it is believed that one of the reasons for the improved surface mobility when the orientation of the fibrous structure is uncreped surface (low density discrete pillow region surface) side out (“FSO”) is the fact that the lower density pillows are on the surface of the fibrous structure. When the fibrous structure undergoes compressive force with the lower density pillows on the surface of the fibrous structure, the fibrous structure will have increased “cushiness”. At the same time, having the low density pillows on the surface of the fibrous structure creates better surface mobility, because a strain imparted on the surface of the fibrous structure will move through the discrete pillow region more easily than through a continuous knuckle region, providing less stress on the surface of the fibrous structure due to the lower density of the discrete pillow region.

In yet another example of the present invention, a single- or multi-ply sanitary tissue product comprising a fibrous structure according to the present invention is provided.

In still yet another example of the present invention, a roll of sanitary tissue product comprising a single-or multi-ply sanitary tissue product according to the present invention is provided.

In even yet another example of the present invention, a package comprising one or more rolls of sanitary tissue product according to the present invention is provided.

Accordingly, the present invention provides fibrous structures, for example sanitary tissue products, such as bath tissue products, that provide improved lotion transfer and/or exhibit better sheet control during the fibrous structure making, for example papermaking, processes, methods for making such fibrous structures, molding members used therein, methods for making such molding members, rolls of sanitary tissue products and packages comprising one or more rolls of sanitary tissue products.

“Sanitary tissue product” as used herein means a soft, low density (i.e. <about 0.15 g/cm) article comprising one or more fibrous structure plies according to the present invention, wherein the sanitary tissue product is useful as a wiping implement for post-urinary and post-bowel movement cleaning (toilet tissue), for otorhinolaryngological discharges (facial tissue), and multi-functional absorbent and cleaning uses (absorbent towels). The sanitary tissue product may be convolutedly wound upon itself about a core or without a core to form a sanitary tissue product roll.

The sanitary tissue products and/or fibrous structures of the present invention may exhibit a basis weight of greater than 15 g/mto about 120 g/mand/or from about 15 g/mto about 110 g/mand/or from about 20 g/mto about 100 g/mand/or from about 30 to 90 g/m. In addition, the sanitary tissue products and/or fibrous structures of the present invention may exhibit a basis weight between about 40 g/mto about 120 g/mand/or from about 50 g/mto about 110 g/mand/or from about 55 g/mto about 105 g/mand/or from about 60 to 100 g/m.

The sanitary tissue products of the present invention may exhibit a sum of MD and CD dry tensile strength of greater than about 59 g/cm (150 g/in) and/or from about 78 g/cm to about 394 g/cm and/or from about 98 g/cm to about 335 g/cm. In addition, the sanitary tissue product of the present invention may exhibit a sum of MD and CD dry tensile strength of greater than about 196 g/cm and/or from about 196 g/cm to about 394 g/cm and/or from about 216 g/cm to about 335 g/cm and/or from about 236 g/cm to about 315 g/cm. In one example, the sanitary tissue product exhibits a sum of MD and CD dry tensile strength of less than about 394 g/cm and/or less than about 335 g/cm.

In another example, the sanitary tissue products of the present invention may exhibit a sum of MD and CD dry tensile strength of greater than about 196 g/cm and/or greater than about 236 g/cm and/or greater than about 276 g/cm and/or greater than about 315 g/cm and/or greater than about 354 g/cm and/or greater than about 394 g/cm and/or from about 315 g/cm to about 1968 g/cm and/or from about 354 g/cm to about 1181 g/cm and/or from about 354 g/cm to about 984 g/cm and/or from about 394 g/cm to about 787 g/cm.

The sanitary tissue products of the present invention may exhibit an initial sum of MD and CD wet tensile strength of less than about 78 g/cm and/or less than about 59 g/cm and/or less than about 39 g/cm and/or less than about 29 g/cm.

The sanitary tissue products of the present invention may exhibit an initial sum of MD and CD wet tensile strength of greater than about 118 g/cm and/or greater than about 157 g/cm and/or greater than about 196 g/cm and/or greater than about 236 g/cm and/or greater than about 276 g/cm and/or greater than about 315 g/cm and/or greater than about 354 g/cm and/or greater than about 394 g/cm and/or from about 118 g/cm to about 1968 g/cm and/or from about 157 g/cm to about 1181 g/cm and/or from about 196 g/cm to about 984 g/cm and/or from about 196 g/cm to about 787 g/cm and/or from about 196 g/cm to about 591 g/cm.

The sanitary tissue products of the present invention may exhibit a density (based on measuring caliper at 95 g/in) of less than about 0.60 g/cmand/or less than about 0.30 g/cmand/or less than about 0.20 g/cmand/or less than about 0.10 g/cmand/or less than about 0.07 g/cmand/or less than about 0.05 g/cmand/or from about 0.01 g/cmto about 0.20 g/cmand/or from about 0.02 g/cmto about 0.10 g/cm.

The sanitary tissue products of the present invention may be in the form of sanitary tissue product rolls. Such sanitary tissue product rolls may comprise a plurality of connected, but perforated sheets of fibrous structure, that are separably dispensable from adjacent sheets.

In another example, the sanitary tissue products may be in the form of discrete sheets that are stacked within and dispensed from a container, such as a box.

The fibrous structures and/or sanitary tissue products of the present invention may comprise additives such as surface softening agents, for example silicones, quaternary ammonium compounds, aminosilicones, lotions, and mixtures thereof, temporary wet strength agents, permanent wet strength agents, bulk softening agents, wetting agents, latexes, especially surface-pattern-applied latexes, dry strength agents such as carboxymethylcellulose and starch, and other types of additives suitable for inclusion in and/or on sanitary tissue products.

“Fibrous structure” as used herein means a structure that comprises a plurality of fibers, for example pulp fibers. In one example, the fibrous structure may comprise a plurality of wood pulp fibers. In another example, the fibrous structure may comprise a plurality of non-wood pulp fibers, for example plant fibers, synthetic staple fibers, and mixtures thereof. In still another example, in addition to pulp fibers, the fibrous structure may comprise a plurality of filaments, such as polymeric filaments, for example thermoplastic filaments such as polyolefin filaments (i.e., polypropylene filaments), such as in the form of a co-formed fibrous structure where the pulp fibers and filaments are commingled together. In one example, a fibrous structure according to the present invention means an orderly arrangement of fibers alone and with filaments within a structure in order to perform a function. Non-limiting examples of fibrous structures of the present invention include paper.

Non-limiting examples of processes for making fibrous structures include known wet-laid papermaking processes, for example conventional wet-pressed papermaking processes and through-air-dried papermaking processes, and air-laid papermaking processes. Such processes typically include steps of preparing a fiber composition in the form of a suspension in a medium, either wet, more specifically aqueous medium, or dry, more specifically gaseous, i.e. with air as medium. The aqueous medium used for wet-laid processes is oftentimes referred to as a fiber slurry. The fibrous slurry is then used to deposit a plurality of fibers onto a forming wire, fabric, or belt such that an embryonic fibrous structure is formed, after which drying and/or bonding the fibers together results in a fibrous structure. Further processing the fibrous structure may be carried out such that a finished fibrous structure is formed. For example, in typical papermaking processes, the finished fibrous structure is the fibrous structure that is wound on the reel at the end of papermaking, often referred to as a parent roll, and may subsequently be converted into a finished product, e.g. a single-or multi-ply sanitary tissue product.

The fibrous structures of the present invention may be homogeneous or may be layered. If layered, the fibrous structures may comprise at least two and/or at least three and/or at least four and/or at least five layers of fiber and/or filament compositions.

In one example, the fibrous structure of the present invention consists essentially of fibers, for example pulp fibers, such as cellulosic pulp fibers and more particularly wood pulp fibers.

In another example, the fibrous structure of the present invention comprises fibers and is void of filaments.

“Co-formed fibrous structure” as used herein means that the fibrous structure comprises a mixture of at least two different materials wherein at least one of the materials comprises a filament, such as a polypropylene filament, and at least one other material, different from the first material, comprises a solid additive, such as a fiber and/or a particulate. In one example, a co-formed fibrous structure comprises solid additives, such as fibers, such as wood pulp fibers, and filaments, such as polypropylene filaments.

“Fibrous elements” as used herein means a fiber and/or a filament.

“Fiber” and/or “Filament” as used herein means an elongate particulate having an apparent length greatly exceeding its apparent width, i.e. a length to diameter ratio of at least about 10. In one example, a “fiber” is an elongate particulate as described above that exhibits a length of less than 5.08 cm (2 in.) and a “filament” is an elongate particulate as described above that exhibits a length of greater than or equal to 5.08 cm (2 in.).

Fibers are typically considered discontinuous in nature. Non-limiting examples of fibers include pulp fibers, such as wood pulp fibers, and synthetic staple fibers such as polyester fibers.

Filaments are typically considered continuous or substantially continuous in nature. Filaments are relatively longer than fibers. Non-limiting examples of filaments include meltblown and/or spunbond filaments. Non-limiting examples of materials that can be spun into filaments include synthetic polymers including, but not limited to thermoplastic polymer filaments, such as polyesters, nylons, polyolefins such as polypropylene filaments, polyethylene filaments, and biodegradable or compostable thermoplastic fibers such as polylactic acid filaments, polyhydroxyalkanoate filaments, polyesteramide filaments, and polycaprolactone filaments. The filaments may be monocomponent or multicomponent, such as bicomponent filaments.

In one example of the present invention, “fiber” refers to papermaking fibers. Papermaking fibers useful in the present invention include cellulosic fibers commonly known as wood pulp fibers. Applicable wood pulps include chemical pulps, such as Kraft, sulfite, and sulfate pulps, as well as mechanical pulps including, for example, groundwood, thermomechanical pulp and chemically modified thermomechanical pulp. Chemical pulps, however, may be preferred since they impart a superior tactile sense of softness to tissue sheets made therefrom. Pulps derived from both deciduous trees (hereinafter, also referred to as “hardwood”) and coniferous trees (hereinafter, also referred to as “softwood”) may be utilized. The hardwood and softwood fibers can be blended, or alternatively, can be deposited in layers to provide a stratified fibrous structure. U.S. Pat. Nos. 4,300,981 and 3,994,771 are incorporated herein by reference for the purpose of disclosing layering of hardwood and softwood fibers. Also applicable to the present invention are fibers derived from recycled paper, which may contain any or all of the above categories as well as other non-fibrous materials such as fillers and adhesives used to facilitate the original papermaking.

In one example, the wood pulp fibers are selected from the group consisting of hardwood pulp fibers, softwood pulp fibers, and mixtures thereof. The hardwood pulp fibers may be selected from the group consisting of: tropical hardwood pulp fibers, northern hardwood pulp fibers, and mixtures thereof. The tropical hardwood pulp fibers may be selected from the group consisting of: eucalyptus fibers, acacia fibers, and mixtures thereof. The northern hardwood pulp fibers may be selected from the group consisting of: cedar fibers, maple fibers, and mixtures thereof.

In addition to the various wood pulp fibers, other cellulosic fibers such as cotton linters, rayon, lyocell, trichomes, seed hairs, and bagasse can be used in this invention. Other sources of cellulose in the form of fibers or capable of being spun into fibers include grasses and grain sources.

“Trichome” or “trichome fiber” as used herein means an epidermal attachment of a varying shape, structure and/or function of a non-seed portion of a plant. In one example, a trichome is an outgrowth of the epidermis of a non-seed portion of a plant. The outgrowth may extend from an epidermal cell. In one embodiment, the outgrowth is a trichome fiber. The outgrowth may be a hairlike or bristlelike outgrowth from the epidermis of a plant.

Trichome fibers are different from seed hair fibers in that they are not attached to seed portions of a plant. For example, trichome fibers, unlike seed hair fibers, are not attached to a seed or a seed pod epidermis. Cotton, kapok, milkweed, and coconut coir are non-limiting examples of seed hair fibers.

Further, trichome fibers are different from nonwood bast and/or core fibers in that they are not attached to the bast, also known as phloem, or the core, also known as xylem portions of a nonwood dicotyledonous plant stem. Non-limiting examples of plants which have been used to yield nonwood bast fibers and/or nonwood core fibers include kenaf, jute, flax, ramie and hemp.

Further trichome fibers are different from monocotyledonous plant derived fibers such as those derived from cereal straws (wheat, rye, barley, oat, etc.), stalks (corn, cotton, sorghum,etc.), canes (bamboo, bagasse, etc.), grasses (esparto, lemon, sabai, switchgrass, etc), since such monocotyledonous plant derived fibers are not attached to an epidermis of a plant.

Further, trichome fibers are different from leaf fibers in that they do not originate from within the leaf structure. Sisal and abaca are sometimes liberated as leaf fibers.

Finally, trichome fibers are different from wood pulp fibers since wood pulp fibers are not outgrowths from the epidermis of a plant; namely, a tree. Wood pulp fibers rather originate from the secondary xylem portion of the tree stem.

In one example, the fibers may comprise monocotyledonous plant derived fibers such as those derived from cereal straws (wheat, rye, barley, oat, etc), stalks (corn, cotton, sorghum,etc.), canes (bamboo, bagasse, etc.), grasses (esparto, lemon, sabai, switchgrass, etc) and mixtures thereof.

“Basis Weight” as used herein is the weight per unit area of a sample reported in lbs/3000 ftor g/m(gsm) and is measured according to the Basis Weight Test Method described herein.

“Machine Direction” or “MD” as used herein means the direction parallel to the flow of the fibrous structure through the fibrous structure making machine and/or sanitary tissue product manufacturing equipment.