Textile structure product including layers each having different levels of cellulose nanoparticles - Patent Application 20070123333

Abstract

To provide novel fiber structures that further optimize the physical product performance of textiles without sacrificing other performance properties such as softness, permeability, printability, ink absorption, barrier properties, absorbency, and paper machine / nonwoven machine reliability. A fibrous structure having at least two layers is disclosed. Each of the at least two layers comprises a blend of structural fibers selected from the group consisting of softwood fibers, non-wood fibers, natural non-cellulose fibers, man-made cellulose or non-cellulose fibers, hardwood fibers, recycled fibers, and mixtures thereof. Each of the at least two layers is arranged in an opposing relationship. The second layer of the at least two layers comprises about 0.05 weight percent to about 20 weight percent cellulose nanoparticles of the second layer.

Description

[Technical field]

[0001] The present disclosure relates to a paper web product comprising cellulose nanoparticles. More specifically, the product is a layered paper fiber structure in which the layers have non-uniform levels of cellulose nanoparticles. The use of selected non-uniform levels of cellulose nanoparticles provides product designers with additional freedom in optimizing the user performance benefits of the manufactured product. [Background technology]

[0002] Paper products such as fine paper, printing paper, paperboard, cement / fiber composites, facial tissue, paper towels, bath tissue, napkins, and other similar products are engineered to provide a balance of several important properties specific to each product type. For example, tissue products should have good bulk, good absorbency, soft feel, and good strength and durability. In another example, fine printing paper should have high smoothness, optimal whiteness, and good printability / ink retention.

[0003] Unfortunately, the balance of performance attributes is generally contained within a limited formulation space or box. Within a product type, when steps are taken to increase one property of the product, other properties of the product are often adversely affected. For example, product designers of tissue products have for many years attempted to balance lower levels of softwood fibers in their paper structures while attempting to obtain sufficient strength and at the same time minimizing the adverse effects on softness, sheet bulk, or absorbency that typically result from the refining of higher levels of these softwood fibers.

[0004] In another example, in multi-use fibrous sheets, particularly those used for paper toweling, napkins and handkerchiefs, increased softwood content, increased refining and cationic / anionic polymer additions have been required to achieve strength targets required for durability requirements, however, all of these effects can adversely affect sheet feel and product absorbency.

[0005] In yet another example of printing paper used for commercial or office printing or personal handwriting, there remains a need to increase strength without a corresponding decrease in ink penetration / absorption. This need increases as environmental benefits drive higher percentages of recycled pulp and / or higher levels of filler in fine paper products. Higher percentages of recycled pulp, especially pulp that has been repeatedly recycled, result in fiber degradation and, as a result, lower strength and quality of the paper product produced. Traditionally, this strength loss has been compensated for by a large increase in synthetic strength additives and resins, which in turn often results in a lower ink absorption in the product. Similarly, higher levels of filler are also compensated for by a large increase in synthetic strength additives and / or increased refining levels, which in turn often results in a lower bulk and / or lower performance paper structure with increased print pick.

[0006] There remains a continuing, and in fact a growing, need to be able to develop printing paper products that have high strength and impermeability while maintaining cost and ink absorbency.

[0007] In other paper segments, there is also a need for more environmentally friendly and compostable barrier properties. Today, these barrier properties can only be achieved using chemical and other non-organic barrier coatings. The targeted use of cellulose nanoparticles within certain product layers can create structures that meet the needs of the product while using a higher percentage of recyclables, compostables, and can have a higher percentage of natural materials.

[0008] Similarly, paperboard products are also affected by increasing levels of recycled pulp. For example, board products used for food storage may experience a loss of strength if the fibers have lower strength, but also a higher permeability of the paper structure. This increase in packaging permeability may result in a loss of antimicrobial protection of the product, resulting in a shorter product shelf life. Traditionally, this is compensated for by an increase in expensive synthetic additives, or by thicker, less permeable plastic coatings that hinder recyclability and compostability.

[0009] Thus, there remains a need for novel fibrous structures that further optimize the physical product performance of textiles without sacrificing other performance properties such as softness, permeability, printability, ink absorption, barrier properties, absorbency, and paper machine / nonwoven machine reliability. Those skilled in the art will recognize that all fibrous sheet making processes can benefit from the selective addition of cellulose nanoparticles, and non-limiting examples of such structures are structures and products made on conventional papermaking assets, conventional dry creped tissue machines, differential density or structured tissue papermaking processes, and air-laid paper machine assets. Summary of the Invention

[0010] The present disclosure provides a fibrous structure comprising at least two layers. Each of the at least two layers comprises a mixture of structural fibers selected from the group consisting of softwood fibers, non-wood fibers, natural non-cellulosic fibers, man-made cellulose or non-cellulosic fibers, hardwood fibers, recycled fibers, and mixtures thereof. Each of the at least two layers is disposed in a facing relationship. A second layer of the at least two layers comprises about 0.05 weight percent to about 20 weight percent of cellulose nanoparticles of the second layer.

[0011] The present disclosure also provides a fibrous structure having a surface layer comprising high aspect ratio nanofilaments.

[0012] The present disclosure further provides a fibrous structure comprising at least two plies arranged in contact in a facing relationship having a longitudinal grain and a transverse and coplanar longitudinal grain, each of the at least two plies comprising a mixture of structural fibers selected from the group consisting of softwood fibers, non-wood fibers, natural non-cellulosic fibers, man-made cellulose or non-cellulosic fibers, hardwood fibers, recycled fibers, and mixtures thereof, a first of the at least two plies comprising a first layer comprising about 0.05 weight percent to about 20 weight percent of cellulose nanoparticles of the first layer. [Brief description of the drawings]

[0013] [Figure 1] FIG. 2 is an illustrative cross-sectional view of a two-layer embodiment of a fibrous substrate of the present disclosure. [Diagram 2] FIG. 2 is an illustrative cross-sectional view of a three-layer embodiment of a fibrous substrate according to the present disclosure, where the outer layer of the substrate comprises cellulose nanoparticles. [Diagram 3] FIG. 2 is an illustrative cross-sectional view of a three-layer embodiment of a fibrous substrate according to the present disclosure, where the inner layer of the substrate comprises cellulose nanoparticles. [Figure 4] FIG. 2 is an illustrative cross-sectional view of a two-layer embodiment of a fibrous substrate fabricated on an illustrated forming wire according to the present disclosure, where a first layer comprising cellulose nanoparticles is the layer formed on the forming wire surface. [Diagram 5] FIG. 2 is an illustrative cross-sectional view of a two-layer embodiment of a fibrous substrate fabricated on an illustrated forming wire according to the present disclosure, where the first layer comprising cellulose nanoparticles is a layer formed without contact with the forming wire. [Figure 6] 1 is an illustrative cross-sectional view of a two-layer embodiment of a fibrous substrate made with a process including two parallel forming wires according to the present disclosure. [Figure 7] FIG. 2 is an illustrative cross-sectional view of a two-layer embodiment of a fibrous substrate according to the present disclosure, in which the first layer comprising high aspect ratio cellulose nanofilaments is the concentrated layer and therefore the thinner layer. [Figure 8]FIG. 2 is an illustrative cross-sectional view of a three-layer embodiment of a fibrous substrate fabricated on an illustrated forming wire according to the present disclosure, where a first layer comprising cellulose nanoparticles is the layer formed on the forming wire surface. [Figure 9] 1 is an illustrative cross-sectional view of a three-layer embodiment of a fibrous substrate made with a process including two parallel forming wires according to the present disclosure. [Figure 10] FIG. 1 is an illustrative cross-sectional view of a three-layer embodiment of a fibrous substrate according to the present disclosure, in which a first layer comprising cellulose nanoparticles is the concentrated layer, and therefore the thinner layer, and is shown in opposing relationship to the second and third layers of the substrate. [Figure 11] 1 is an exemplary flow diagram of a typical paper machine. [Figure 12] 12A-12E are illustrative flow diagrams of a typical converting operation suitable for combining two separate layered plies of fibrous material. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Despite many papers on the use of cellulose nanoparticles in fibrous structures, cellulose nanoparticle terminology is still not unified and inconsistent terms are used to describe cellulose particles. The term "cellulose nanoparticles" as used herein refers to cellulose particles with at least one dimension being nanoscale. Cellulose nanoparticles include, but are not limited to, microfibrillated cellulose (MFC), nanofibrillated cellulose (NFC), algal cellulose particles (AC), bacterial cellulose particles (BC), and high aspect ratio cellulose nanofilaments (CNF).

[0015] The present disclosure relates to a fibrous substrate 100 that includes at least two layers. A first of the layers 110 and a second of the layers 120 are disposed in contact in a facing relationship. Each of the first and second layers is formed of a plurality of overlapping fibers and other constituents as required for the end use of the particular substrate, and the first layer includes a plurality of cellulose nanoparticles 150. The layers of the paper web substrate 100 are formed of a plurality of overlapping fibers selected from the group consisting of softwood fibers, non-wood fibers, natural non-cellulose fibers, man-made cellulose or non-cellulose fibers, hardwood fibers, and mixtures thereof, fillers, active ingredients, and combinations thereof. Preferably, the first layer of the paper web substrate includes at least about 0.05 weight percent nanoparticles, and the second layer does not include directly added cellulose nanoparticles. In another embodiment, it is envisioned that at least two layers each contain cellulose nanoparticles, but the composition of the cellulose nanoparticles in the layers is different, each having at least about 0.05 weight percent cellulose nanoparticles.

[0016] As used herein, "paper web substrate" traditionally refers to any wet-formed or dry-laid fibrous structure product that includes, but is not necessarily, cellulose fibers. Paper web substrate embodiments may include, but are not limited to, tissue products such as sanitary tissue products, toweling products such as absorbent towels, paperboard grades, paper packaging substrates, papers used in high pressure laminate constructions, papers used for printing and writing, and fibrous substrates used in airlaid nonwoven products. Other embodiments of paper web substrates contemplated in this disclosure also include, but are not limited to, initial dry-laid webs such as those used in airlaid fabrication processes that include a loosely bonded "fluffy" structure of desired fibers.

[0017] "Fiber structure" as used herein means a structure that includes one or more fiber layers. In one example, a fiber structure according to the present disclosure means an ordered arrangement of fibers within a structure to perform a function. Non-limiting examples of fiber structures of the present disclosure may include paper substrates of all forms, nonwoven substrates, and composites (including reinforced plastics and reinforced cements).

[0018] As used herein, "conversion operations" refers to additional processing steps in which the fibrous structure is coated, combined, embossed, cut, or otherwise treated to create a product better suited for the task it was designed to perform. These operations may occur either immediately after the web is formed on the paper machine, or after it has been run through separate processes and machines.

[0019] Non-limiting examples of processes for making fibrous web structures include the known wet-laid and air-laid (also known as nonwoven) papermaking processes. Those skilled in the art will recognize that such processes typically include a step for preparing a fibrous composition in the form of a suspension in a medium, either wet, more specifically an aqueous medium, or dry, more specifically a gaseous or air-based medium. The aqueous medium used in the wet process is often called a fiber slurry. The fiber suspension is then used to deposit a plurality of fibers onto a forming wire or belt so that an initial fibrous structure is formed, and then the fibers are dried and / or bonded together to result in a fibrous structure. The fibrous structure may be further processed to form a final fibrous structure. For example, in a papermaking process, finishing may include localized treatments, either on-line or off-line, to create an intermediate structure, and / or one or more plies may be combined to create a final substrate. In many fibrous web making processes, the final fibrous structure may be wound or sheeted and subsequently converted into a final product through additional "converting operations".

[0020] Figure 11 shows a non-limiting example of a wet paper machine. In a typical paper machine, there are at least five distinct operating sections: The forming section, commonly called the wet end, takes the aqueous solution of fibers and other constituents and creates the embryonic web (in a drylay paper machine, the fibers are dispersed in air before creating the embryonic web). The press section removes a significant amount of residual water through a system of nips formed by rolls pressing against each other, assisted by press felts which support the sheet and absorb the forced out water. The dryer section of a papermaking machine, as the name suggests, dries the paper, either by a series of internal steam-heated cylinders that evaporate the water, or by other external means that dry the web. (In a drylay papermaking machine, the press and dryer sections are replaced by a bonding and curing process, where heat and / or chemicals are used to treat the web to create the final structure.) · The finishing section is where the paper is smoothed and or coated / treated to provide specific surface or structural changes such as coating, sizing, surface modification and / or calendaring under high load and pressure. In the reeling section, the paper coming out of the paper machine is wound onto spools for further processing.

[0021] There may also be a coating section to modify the surface properties with a coating, a non-limiting example of a coating is kaolin clay.

[0022] The papermaking process can be adapted to allow the addition of any number of specialty materials or chemicals to provide special functionality to the finished paper. Sizing agents such as resins, glues, or starches can be added to the web to modify its properties by improving the paper's water resistance, reducing its ability to fluff, reducing abrasiveness, improving its print properties and surface bond strength. These sizing agents may be applied at the wet end (internal sizing), or at the dry end (surface sizing), or both. At the dry end, the sizing is usually applied with a size press. The size press may be a roll applicator (flooded nip) or a nozzle applicator. It is usually located before the last dryer section. Some papermakers also use a "coater" to apply a coating of pigments such as calcium carbonate or china clay, usually suspended in a binder of cooked starch and styrene butadiene latex. The coating creates a very smooth bright surface with the best print quality. Some papermakers may also use calendering or supercalendering to enhance surface structure, improve printability, and / or alter sheet stiffness.

[0023] Those skilled in the art will recognize that the process of making fibrous webs is highly adaptable and customizable to allow for the creation of structures for various end uses by varying either the base materials and / or unit operations to better create the desired structure. A non-limiting example of this customization is the addition of creping blades and larger dryer rolls (Yankees) to some types of tissue machines. Another non-limiting example is the use of dry fiberization (i.e., hammer mills to "fluff" dry fibrous webs) equipment, and air delivery systems to create dry / airlaid structures.

[0024] In a traditional papermaking machine forming section or wet end, a dilute aqueous mixture of fibers and other product materials is fed to a headbox before being deposited onto the wire. The purpose of the headbox is to create turbulence, prevent the fibers from clumping together, and create a uniform basis weight material across the papermaking machine. The headbox may contain one or more layers, which may have the same or different aqueous solutions fed to them. From the headbox, the aqueous slurry is deposited onto a moving wire or fabric loop. The slurry is then optionally dewatered to create the desired structure.

[0025] Again, one skilled in the art will recognize that paper machines can be modified depending on the desired paper feed material, basis weight, and sheet construction. One non-limiting modification is the addition of a second headbox, which is added to the wet end to lay a different fiber blend on top of the partially formed base layer. The secondary headbox is usually located at the point where the base sheet is completely drained. It is not considered a separate ply because the action of water works to mix the fibers of the top and bottom layers. Secondary headboxes are common in the production of linerboard.

[0026] Another non-limiting example of a forming / wet end section modification is the addition of a second wire above the drainage table. The bottom and top wires meet, resulting in some drainage from both sides of the sheet. The top wire improves formation and also provides more drainage, helping the machine to increase speed and produce a particular paper grade at an economical rate. Twin wire machines or gap formers use two vertical wires in the forming section, which increases the dewatering rate of the fiber slurry while also giving a uniform two-sidedness.

[0027] Tissue products "Tissue" or "towel" paper products refer to products made with paper tissue or toweling techniques, including, but not limited to, conventional felt-pressed or conventional wet-pressed tissue paper, pattern densified tissue paper, through-air-drying paper with or without creping. For example, the papermaking process of the present disclosure can utilize adhesive creping, wet-creping, double creping, embossing, wet-pressing, air-pressing, through-air-drying, through-air-drying with creping, through-air-drying without creping, and other steps in forming the paper web. Some examples of such techniques are disclosed in U.S. Patent Nos. 4,529,480, 5,048,589, 5,399,412, 5,129,988, 5,494,554, 5,607,511, 6,398,916, 7,744,726, and 8,388,803, all of which are incorporated herein in a manner consistent with this disclosure. When forming a multi-ply tissue product, the separate plies can be made from the same or different processes, as desired.

[0028] For example, in one embodiment, the tissue web may be a creped through-air-dried web formed using processes known in the art. In other embodiments, the base web is formed by a non-creped through-air-dried process. Related non-creped through-air-dried tissue processes are described, for example, in U.S. Patent Nos. 5,656,132 and 6,017,417, both of which are incorporated herein by reference in a manner consistent with this disclosure.

[0029] Tissue embodiments of fibrous structures according to the present disclosure may be in the form of through-air dried fibrous structures, differential density fibrous structures, differential basis weight fibrous structures, wet-laid fibrous structures, airlaid fibrous structures, creped or uncreped fibrous structures, pattern densified or non-pattern densified fibrous structures, compressed or uncompressed fibrous structures, double recreped fibrous structures, as are known in the art, as exemplified in U.S. Pat. Nos. 3,301,746, 3,974,025, 4,191,609, 4,637,859, 6,398,906, and 8,388,803.

[0030] Airlaid Process "Air-laying" is a well-known process by which fibrous nonwoven layers can be formed. In the air-laying process, individual fibers or bundles of fibers, having typical lengths ranging from about 0.5 to about 52 millimeters (mm), are separated and entrained in an air supply and then deposited on a forming screen, usually with the assistance of a vacuum supply. The randomly deposited fibers are then bonded together, for example, using hot air that activates a binder component or latex adhesive. Air-laying is taught, for example, in U.S. Pat. Nos. 4,640,810, 4,494,278, 5,527,171, 4,375,448, or other similar methods. Webs produced by these methods may subsequently be bonded together by heat fusing, latex bonding, or a combination thereof to form webs of sufficient tensile strength, which are well known in the art. The webs produced in this document are best exemplified by, but not limited to, the DANWEB process.

[0031] Airlaid nonwovens are particularly well suited for use as wet wipes. Airlaid nonwovens may have a basis weight ranging from about 30 to about 350 grams per square meter (gsm) with staple fibers of about 0.5 to 10 denier and about 6 to 15 millimeters in length. Wet wipe substrates may generally have a dry fiber density of about 0.025 g / cc to about 0.2 g / cc.

[0032] "Layer" as used herein means that portion of a ply having some thickness and containing natural or artificial fibers, fillers, and / or other necessary additives. The layers may be supplied from different sources. For example, different furnishes may be supplied from the same or different headboxes to a single ply structure having multiple separate layers of intermingled fibers. Each furnish may contain any combination of natural or synthetic fibers as discussed above. Also, without wishing to be limited by theory, it is believed that the layers are not completely separate, but rather that at the boundary between the two layers, there is some intermixing of the components between the different layers.

[0033] Because the layers are constructed into a single fibrous structure, they are arranged in a face-to-face relationship, i.e., each length-by-width face of one layer is adjacent to a parallel face of another layer.

[0034] As used herein, a "ply" is a fibrous substrate containing one or more layers. The plies may be processed through a conversion process and embossed, laminated, or bonded together to create a final fibrous structure. The fibrous structure of the present disclosure contemplates one or more plies arranged in a facing relationship relative to each other. Specifically, a fibrous structure containing two plies may have a first ply having one or more layers and a second ply having one or more layers, each engaged in a facing relationship. Each ply may be formed from multiple layers each including overlapping fibers. However, each ply may include different components, creating a fibrous structure having a structure including non-uniform layers. The first ply of the at least two plies may include multiple cellulose nanoparticles and / or other fibers. The second ply of the at least two plies may be essentially nanoparticle-free or may contain the same or different amount of cellulose nanoparticles as the first ply.

[0035] "Fiber" as used herein means an elongated physical structure whose apparent length is significantly greater than its apparent diameter, i.e., having a length to diameter ratio of at least about 10 and less than 200. Fibers having non-circular cross-sections and / or tubular shapes are common; the "diameter" in this case can be considered to be the diameter of a circle having a cross-sectional area equal to that of the fiber. More specifically, as used herein, "fiber" refers to fibers that make up fibrous structures. The present disclosure contemplates the use of various fibrous structure making fibers (also referred to herein as "structural fibers"), such as, for example, softwood fibers, non-wood fibers, natural non-cellulosic fibers, man-made cellulose or non-cellulosic fibers, hardwood fibers, recycled fibers, or any suitable fibers, and mixtures thereof. The fibers can be natural or man-made fibers, and further the fibers can be virgin or recycled fibers. Man-made fibers can include both those composed of cellulosic materials and those composed of non-cellulosic materials. These fibers can be created / manufactured by any of the processes known to those skilled in the art. Additionally, fibers contemplated by this disclosure include non-wood fibers, hardwood fibers, softwood fibers, and man-made fibers, recycled fibers, and combinations thereof.

[0036] Recycled fibers may be added to the furnish in any amount. Recycled fibers contemplated in this disclosure include both pre-consumer and post-consumer sources. Although any suitable recycled fiber may be used, recycled fibers having relatively low levels of groundwood pulp may be used.

[0037] The term "cellulose nanoparticles" as used herein refers to cellulose particles with at least one dimension being nanoscale. Cellulose nanoparticles include, but are not limited to, microfibrillated cellulose (MFC), nanofibrillated cellulose (NFC), algal cellulose particles (AC), bacterial cellulose particles (BC), and high aspect ratio cellulose nanofilaments (CNF). "Cellulose nanoparticles" as used in this disclosure may be derived from either softwood and / or hardwood and therefore may contain fibrous elements of softwood or hardwood.

[0038] Microfibrillated cellulose (MFC) is defined herein as a fibrous material composed of cellulose fibrils that are very thin, with diameters of about 5-100 nm, with an average of about 20 nm, and fibril lengths of about 20 nm-200 μm, but typically 100 nm-100 μm.

[0039] Nanofibrillated cellulose (NFC) is a specific class of MFC with fiber dimensions at the lower end of the fibril size range mentioned above. In MFC, individual microfibrils are partially or completely separated from each other. Fibers that are fibrillated and have microfibrils on their surface, and microfibrils that are separated and in the aqueous phase of the slurry are included in the definition of MFC. The cellulose nanoparticles in the present disclosure can be made from any process known to those skilled in the art. The processes used to create cellulose nanoparticles include, but are not limited to, chemical fiber processing, including improved refinement equipment, homogenizer, ultrasonic fiber processing, and enzyme fiber modification.

[0040] The components of microfibrillated cellulose are: [Table 1] See Gary Chinga-Carrasco, “Cellulose fibres, nanofibrils and microfibrils: The morphological sequence of MFC components from a plant physiology and fibre technology point of view”, Table 1, Nanoscale Res Lett. 2011; 6(1): 417, published online June 13, 2011.

[0041] "High aspect ratio cellulose nanofilaments" are another subset of MFCs, with unique dimensions. High aspect ratio means that the fiber length divided by the fiber width is at least in the range of about 200 to about 5000, or about 600 to about 1000. These cellulose nanofilaments have an average width in the nanometer range, for example, an average width in the range of about 30 nm to about 500 nm, and an average length in the micrometer range or beyond, for example, an average length of about 6 μm to about 2.5 mm. The cellulose nanofilaments may have an average thickness in the range of about 20 nm to about 600 nm, or about 30 nm to about 500 nm. Such cellulose nanoparticles can be obtained, for example, from mechanical processes. Exemplary processes are described in U.S. Patent Application Publication Nos. 2013 / 0017394 and 2015 / 0057442.

[0042] Those skilled in the art will recognize that cellulose nanoparticles are difficult to obtain as a homogenous material or "pure form," and thus nanoparticle materials contain many times mixtures of material lengths as a result of the mechanical or chemical processes by which they are produced. For example, exemplary cellulose nanoparticles have at least about 40% by weight, or at least about 75% by weight, or at least about 90% by weight of the cellulose nanoparticles in the purified mixture with an average particle length of greater than 6 μm and a diameter of about 30-500 nm.

[0043] Another envisioned use of cellulose nanoparticles possible in the embodiments contemplated in this disclosure is to include either pure cellulose nanoparticles and / or mixtures of cellulose nanoparticles with other refined products in a small percentage in virgin or recycled pulp streams before being transported to the papermaking site. In this way, a virgin fiber source can be enriched through cellulose nanoparticle addition, and then cellulose nanoparticles can be added to the papermaking process without introducing a new fiber input stream. By dosing nanoparticles with cellulose at the pulp manufacturing facility, it would be possible to produce what could be called a "super pulp" with properties that are only possible with the inclusion of cellulose nanoparticles. Thus, many different methods for cellulose nanoparticle addition are contemplated in this disclosure, including the direct inclusion of pure cellulose nanoparticles, including but not limited to mixtures of cellulose nanoparticles with other refined by-products with nanoparticle content greater than 50%, and cellulose nanoparticles are added by inclusion in virgin or recycled fibers before being included at the paper mill.

[0044] The phrase "fibrillated cellulose fibers" as used herein refers to cellulose fibers that have been subjected to a mechanical or chemical treatment during which individual cellulose filaments or bundles of cellulose filaments are liberated from the fiber body but remain attached to the fiber at one end, creating a larger bond area and increased fiber-fiber contact. The extent of the treatment determines the number of cellulose nanoparticles released from the fiber.

[0045] Algal cellulose particles (AC) are microfibrils extracted from the cell walls of various algae by acid hydrolysis and / or mechanical purification. The resulting microfibrils are microns in length and have a high aspect ratio.

[0046] Bacterial cellulose particles (BC) are microfibrils secreted by various bacteria isolated from bacterial bodies and growth media. The resulting microfibrils are microns in length and have a high aspect ratio.

[0047] Those skilled in the art will recognize that the fibers of the fibrous structures contemplated in this disclosure may include fibers created from multiple sources and base materials. "Fibrillated man-made non-cellulosic fibers" are contemplated, along with "synthetic polymer fibers" and similar terminology, which refer to non-cellulosic fibers made from synthetic polymers, such as polyester, nylon, and polyolefins. Split-type fiber preparations to create splittable fibers are generally known in the context of thermoplastic fibers, where the fibers have segments formed from different polymers. See U.S. Patent Nos. 5,759,926, 5,895,710, and U.S. Patent Application Publication No. 2003 / 0203695.

[0048] Splittable fibers produced and utilized in connection with the present disclosure may have a split pie shape, an islands-in-the-sea configuration, a side-by-side configuration, a hollow configuration, etc. See U.S. Patent No. 4,735,849 and U.S. Patent Application Publication No. US2002 / 0168912, Figures 2-9. Splittable fibers are suitably disintegrated prior to incorporation into the furnish, as discussed below.

[0049] During the preparation of some fibers for wet papermaking operations, softwood fiber pulps and some hardwood fiber pulps are optionally subjected to mechanical or chemical processing, whereby the fibers are compressed, subjected to high shear, and / or chemically treated to make the fibers softer and create increased fiber-to-fiber bonded area through fiber fibrillation, fiber swelling, and / or increased fiber flexibility. Those skilled in the art will recognize that there are three major products of pulp fiber refining: 1) a percentage of the fibers are not affected at all by the refining intensity and consistency, 2) a significant percentage of the fibers are fibrillated, which strips the fiber cell walls and exposes the microfibrils that remain attached to the original fiber, and 3) a percentage of the fibers and microfibrils are cut or mechanically broken into very small pieces (<74 microns long), this fraction being referred to as the fine fiber fraction. These fines can be either primary (those present in the natural wood source) or secondary (those created during the refining process).

[0050] The fibrous substrate 100 of the present disclosure can include at least one layer including nanoparticles 150. The second layer 110 can include a plurality of cellulose nanoparticles. The second layer 110 can include at least about 0.05 percent by weight of the second layer, or between about 0.05 percent and about 20 percent by weight, or between about 0.1 percent and about 5 percent by weight of the nanoparticles.

[0051] The first layer 120 of the at least two layers 120 may be free of cellulose nanoparticles. Specifically, the first layer 120 may not contain directly added cellulose nanoparticles. The first layer 120 may not contain intentionally or purposefully added cellulose nanoparticles. "Intentionally" and / or "intentionally" as used herein means a voluntary, deliberate act with a specific intention to add cellulose nanoparticles to the first layer 120. Such a first layer 120 without intentionally added cellulose nanoparticles may be observed in that the first layer 120 may contain less than about 0.50 weight percent, or less than about 0.25 weight percent, or less than about 0.10 weight percent, or less than about 0.05 weight percent of the first layer 120 cellulose nanoparticles.

[0052] One skilled in the art can envision that the first layer 120 also contains nanoparticles, either in the same or significantly different loading as the second layer 110. In particular, the first layer 120 may contain more or less cellulose nanoparticles, depending on the desired characteristics of the final product. The first layer 120 may include more than about 0.05 percent, or more than about 0.10 percent, of cellulose nanoparticles.

[0053] By layering fibrous structured products to vary the levels of cellulose nanoparticle concentration throughout the thickness of the structure, formulation options for achieving higher performing paper products are dramatically expanded.

[0054] "Weight per unit area" as used herein means lbs / 3000ft 2 or g / m 2 The weight per unit area of ​​the sample is reported in gsm. Fibrous web-based tissue embodiments of the present disclosure have a weight per unit area of ​​about 5 g / m 2 ~Approx. 150g / m 2 , preferably about 10 g / m 2 ~Approx. 120g / m 2 , more preferably about 20 g / m 2 ~about 100g / m 2The paper embodiment of the fibrous web structure of the present disclosure may exhibit a basis weight of about 25 g / m 2 ~Approx. 350g / m 2 , preferably about 50 g / m 2 ~about 300g / m 2 , more preferably about 75 g / m 2 ~about 250g / m 2 The paperboard embodiment of the fibrous web structure of the present disclosure may exhibit a basis weight of about 300 g / m 2 ~about 1000g / m 2 , preferably about 400 g / m 2 ~about 800g / m 2 , more preferably about 400 g / m 2 ~about 600g / m 2 The weight of the item may be indicated.

[0055] The weight of land is determined by the area (m 2 ), and by weighing the sample(s) of fibrous structure and / or paper product comprising such fibrous structure according to the present disclosure on a top-loading balance having a minimum resolution of 0.01 g. The balance is protected from air currents and other disturbances using a draft shield. The weight is recorded when the balance reading is constant. The average weight (g) and the average area (m) of the samples are then measured. 2 ) is calculated. 2 ) is the average weight (g) divided by the average area (m 2 ) is calculated by dividing it by

[0056] FIG. 1 illustrates a cross-sectional view of an exemplary embodiment of a fibrous structure or ply 100 of the present disclosure, including a second layer 110 and a first layer 120. In some embodiments, the second layer 110 may include a specific mixture of fibers, fillers, active ingredients, other fibers, and combinations thereof selected from the group consisting of softwood fibers, non-wood fibers, natural non-cellulose fibers, man-made cellulose or non-cellulose fibers, hardwood fibers, recycled fibers, and mixtures thereof. In some embodiments, the first layer 120 may also contain a specific mixture of fibers, fillers, active ingredients, other fibers, and combinations thereof selected from the group consisting of softwood fibers, non-wood fibers, natural non-cellulose fibers, man-made cellulose or non-cellulose fibers, hardwood fibers, and mixtures thereof. The second layer 110 may include at least about 0.05% (i.e., greater than about 0.05%), or between about 0.05% and about 20%, or between about 0.1% and about 5% nanoparticles by weight of the second layer 110.

[0057] 2 shows a cross-sectional view of an exemplary embodiment of a fibrous structure or ply 100 of the present disclosure, including a second layer 110, a first layer 120, and a third layer 130 disposed proximate the outer surface of the fibrous structure. Each of the three layers (110, 120, and 130) may include a particular mixture of softwood fibers, non-wood fibers, natural non-cellulosic fibers, man-made cellulose or non-cellulosic fibers, hardwood fibers, recycled fibers, and mixtures thereof, fillers, active ingredients, other fibers, and combinations thereof. In one embodiment, the second layer 110 may include greater than about 0.05%, or between about 0.05% and about 20%, or between about 0.1% and about 5% nanoparticles by weight of the second layer 110.

[0058] 3 shows a cross-sectional view of an exemplary embodiment of a fibrous structure or ply 100 of the present disclosure, including a second layer 110, a first layer 120, and a third layer 130, each as one of the inner layers of the fibrous structure. In some embodiments, each layer (110, 120, 130) of the fibrous structure may include a particular mixture of softwood fibers, non-wood fibers, natural non-cellulosic fibers, man-made cellulose or non-cellulosic fibers, hardwood fibers, recycled fibers, and mixtures thereof, fillers, active ingredients, other fibers, and combinations thereof. In one embodiment, the second layer 110 may include greater than about 0.05%, or between about 0.05% and about 20%, or between about 0.1% and about 5% nanoparticles by weight of the second layer 110.

[0059] 4 shows a cross-sectional view of an exemplary embodiment of a fibrous structure or ply 100 of the present disclosure, including a first layer 120 and a second layer 110, where the structure is formed with the second layer 110 formed directly on the forming belt / fabric / wire 200 of a paper machine or nonwoven machine. The first layer 120 and / or the second layer 110 may include certain mixtures of softwood fibers, non-wood fibers, natural non-cellulosic fibers, man-made cellulose or non-cellulosic fibers, hardwood fibers, recycled fibers, and mixtures thereof, fillers, active ingredients, other fibers, and combinations thereof. In one embodiment, the second layer 110 may include greater than about 0.05%, or between about 0.05% and about 20%, or between about 0.1% and about 5% nanoparticles by weight of the second layer 110.

[0060] 5 shows a cross-sectional view of an exemplary embodiment of a fibrous structure or ply 100 of the present disclosure, including a second layer 110 and a first layer 120, where the structure is formed with the second layer 110 formed in a layer away from the forming belt / fabric / wire 200 of a papermaking machine. The first layer 110 and / or the second layer 120 may include certain mixtures of softwood fibers, non-wood fibers, natural non-cellulosic fibers, man-made cellulose or non-cellulosic fibers, hardwood fibers, recycled fibers, and mixtures thereof, fillers, active ingredients, other fibers, and combinations thereof. In one embodiment, the second layer 110 may include greater than about 0.05%, or between about 0.05% and about 20%, or between about 0.1% and about 5% nanoparticles by weight of the second layer 110.

[0061] 6 shows a cross-sectional view of an exemplary embodiment of a fibrous structure or ply 100 of the present disclosure, where the fibrous structure 100 includes a first layer 120 and a second layer 110 formed in a double belt / wire making process, where both the first layer 120 and the second layer 120 are formed in contact with one of the two forming belts / fabrics 200 and 210 of a paper machine / nonwoven machine. In some embodiments, the first layer 120 and / or the second layer 110 may include certain mixtures of softwood fibers, non-wood fibers, natural non-cellulosic fibers, man-made cellulose or non-cellulosic fibers, hardwood fibers, recycled fibers, and mixtures thereof, fillers, active ingredients, other fibers, and combinations thereof. In one embodiment, the second layer 110 may include greater than about 0.05%, or between about 0.05% and about 20%, or between about 0.1% and about 5% nanoparticles by weight of the second layer 110.

[0062] FIG. 7 shows a cross-sectional view of an exemplary embodiment of a fibrous structure or ply 100 of the present disclosure, including a first layer 110 and a second layer 120, where the second layer 110 is a high concentration of high aspect ratio cellulose nanofilaments. Such structures may be produced by directly adding a high concentration of high aspect ratio cellulose nanofilaments, such as in a headbox, spraying, coating, gravure application, or other direct application process. In some embodiments, the second layer 120 may contain a particular mixture of softwood fibers, recycled material fibers, hardwood fibers, man-made cellulose or non-cellulose fibers, fillers, and / or active ingredients, and / or other fibers. As shown in FIG. 7, the second layer 120 includes at least about 40.0% (greater than about 40.0%), or greater than 50.0%, or between about 55.0% and about 100% high aspect ratio cellulose nanofilaments 150 by weight of the second layer 110.

[0063] 8 shows a cross-sectional view of an exemplary embodiment of a fibrous web structure or ply 100 of the present disclosure, including a first layer 120, a second layer 110, and a third layer 130, where the structure is formed with the second layer 110 formed directly on a forming belt / fabric 200 of a papermaking machine. In some embodiments, the first layer 120, the second layer 110, and / or the third layer 130 may include certain mixtures of softwood fibers, non-wood fibers, natural non-cellulosic fibers, man-made cellulose or non-cellulosic fibers, hardwood fibers, recycled fibers, and mixtures thereof, fillers, active ingredients, other fibers, and combinations thereof. In one embodiment, the second layer 110 may include greater than about 0.05%, or between about 0.05% and about 20%, or between about 0.1% and about 5% nanoparticles by weight of the fibrous structure. One skilled in the art can envision the second layer 110 being formed either on the wire side (150) or on the opposite side of the fiber structure (130). In yet another embodiment, the first layer 110 can include greater than about 0.05% by weight of the second layer 110, or between about 0.05% and about 20% by weight, or between about 0.1% and about 5% by weight of nanoparticles.

[0064] 9 shows a cross-sectional view of an exemplary embodiment of a fibrous structure or ply 100 of the present disclosure, including a first layer 120, a second layer 110, and a third layer 130, formed in a dual belt / wire making process, where the fibrous structure 100 is formed in contact with one of a papermaking machine's two forming belts / fabrics 200 and 210. In some embodiments, the first layer 120, the second layer 110, and the third layer 130 may include certain mixtures of softwood fibers, non-wood fibers, natural non-cellulosic fibers, man-made cellulose or non-cellulosic fibers, hardwood fibers, recycled fibers, and mixtures thereof, fillers, active ingredients, other fibers, and combinations thereof. In one embodiment, the second layer 110 may include greater than about 0.05% nanoparticles by weight of the second layer 110, or between about 0.05% and about 20%, or between about 0.1% and about 5% nanoparticles by weight of the second layer 110.

[0065] 10 shows a cross-sectional view of an exemplary embodiment of a fibrous structure or ply 100 of the present disclosure, including a second layer 110, a first layer 120, and a third layer 130, where the second layer 110 has a high concentration of high aspect ratio cellulose nanofilaments. Such a fibrous structure 100 may be produced by directly adding a high concentration of cellulose nanoparticles and / or high aspect ratio cellulose nanofilaments, such as in a headbox, spraying, coating, gravure application, or other direct application process. The first layer 120 and the third layer 130 may contain a particular mixture of softwood fibers, recycled material fibers, hardwood fibers, man-made cellulose or non-cellulose fibers, fillers, and / or active ingredients, and / or other fibers. In one embodiment shown in FIG. 10, the second layer 110 comprises at least about 40.0% (greater than about 40.0%) by weight of the second layer 110, or greater than about 50.0% by weight, or between about 55.0% and about 100% by weight of the second layer 110, cellulose nanoparticles and / or cellulose nanofilaments and / or high aspect ratio cellulose nanofilaments 150.

[0066] FIG. 12A shows a cross-sectional view of an exemplary embodiment of a fiber structure 100A of the present disclosure, including a first ply 210 and a second ply 220, where the first ply 210 has a layered, similar or different concentration of cellulose nanoparticles as the second ply. The two plies, each with three layers, once combined, create a different structure and function than a single ply structure. In some embodiments, each ply may also contain layers that may contain a particular mixture of softwood fibers, recycled material fibers, hardwood fibers, man-made cellulose or non-cellulose fibers, fillers, and / or active ingredients, and / or other fibers. In one embodiment shown in FIG. 12A, the first ply 210 may include three layers. Layer #1 contains at least about 40.0% (greater than about 40.0%), or greater than 50.0%, or between about 55.0% and about 100% cellulose nanoparticles 150 by weight of layer #1. Similarly, the second ply 220 includes three layers, with layer #1 containing at least about 40.0% (greater than about 40.0%), or greater than 50.0%, or about 55.0% to about 100% cellulose nanoparticles 150 by weight of the first layer of ply 220. In addition, the first ply 210 may further include a second layer (e.g., layer #2). The second layer may not contain intentionally added cellulose nanoparticles.

[0067] Another embodiment envisioned is a combination of layered and non-layered plies to create a final fibrous structure. Those skilled in the art can also recognize that layered plies contain at least one layer containing a particular mixture of softwood fibers, recycled material fibers, hardwood fibers, man-made cellulose or non-cellulose fibers, fillers, and / or active ingredients, and / or other fibers. In one embodiment, the first ply includes at least two layers. Layer #1 contains at least about .05% (more than about .05%), or 0.05% to about 20.0% cellulose nanoparticles by weight of layer #1. The second ply is a homogenous fibrous structure containing 0.05% to 20% cellulose nanoparticles by weight of the ply. In another embodiment, the second homogenous fibrous ply may contain less than 0.05% cellulose nanoparticles.

[0068] In yet another embodiment, the first ply may contain nanoparticles in at least one layer, and the nanoparticles may be loaded in different layers at the same or different loadings. Those skilled in the art can envision many structures that can be created by independently varying the furnish composition of each ply, each layer in ply 1, and the content of cellulose nanoparticles in each layer of the ply, and the number of plies combined to create the final structure. In addition to combining homogeneous plies with or without cellulose nanoparticles, those skilled in the art can further envision that the method of applying cellulose nanoparticles in a separate layer of ply 1 allows the compounder to further optimize the attributes of the final product. In many applications, the nanoparticle loading may be 0.05-20% by weight of the layer in ply 1 or homogeneous ply 2, although surface layers containing more than 40% nanoparticles by weight of the surface layer are also envisioned.

[0069] Those skilled in the art can also recognize that there may be a myriad of structures that can be created by independently varying the furnish composition of the layers within each ply, the content of cellulose nanoparticles in each layer of the ply, and the number of plies combined to create the final structure. Those skilled in the art can further envision that the method of applying the cellulose nanoparticles in separate layers allows the formulator to optimize the attributes of the final product. Non-limiting samples of example structures envisioned are shown in Figures 12B, 12C, 12D, and 12E. Nanoparticles are envisioned to be present in at least one layer in at least one ply, and may be placed in different layers at the same or different loadings. In many applications, the nanoparticle loading may be 0.05-20% of the layer in which it is incorporated. In other applications, the nanoparticle loading may contain less than 0.05% of the layer in which it is incorporated.

[0070] Optional Ingredients - Chemical Papermaking Additives If desired, various chemical additive compositions may be optionally used to further enhance consumer desired benefits such as softness, low lint, absorbency, sheet flexibility, and temporary and / or permanent wet strength additives. Those skilled in the art will recognize that different materials may be added to the papermaking / nonwoven process depending on the papermaking / nonwoven process and end use of the product, non-limiting examples include, but are not limited to, mineral additives, optical brighteners, sizing agents, coatings, debonders, silicone softening additives, non-silicone softening additives, strength additives, absorbency additives, biocides, retention aids, and aesthetic additives.

[0071] Mineral Additives Many fiber-based products contain mineral additives called fillers. A non-limiting example is a paper product that may contain a primarily cellulose fiber web and a defined amount of mineral and / or organic fillers. Fillers, as the name suggests, are used to fill the spaces enclosed by the cellulose fibers of the web. Fillers also improve certain paper properties, including opacity, whiteness, and printability. Other additives, such as pigments, dyes, starches, sizing agents, and strength-enhancing polymers, may also be used to form paper with desired end-product properties. Traditionally, minerals such as kaolin clay (hydrated aluminum silicate), chalk, ground limestone or marble (calcium carbonate), talc (hydrated magnesium silicate), gypsum (calcium sulfate), diatomaceous earth (silicon dioxide), and titanium dioxide have been used as fillers. Most other fillers are inorganic materials produced synthetically from minerals (e.g., titanium dioxide, synthetic silica, barium sulfate) or by regeneration after purification (e.g., limestone-lime-precipitated calcium carbonate). Fillers used to form paper products using methods developed prior to this disclosure decrease the strength properties of the product, such as breaking length in kilometers (tensile strength / basis weight x 102, per TAPPI method T494) as the percentage of filler used to make such products increases. Depending on the desired properties of the desired paper product, fillers can be incorporated in any amount from 0% to about 75%, preferably from about 5% to about 60.0%, more preferably from about 10% to about 50.0%, and even more preferably from about 20% to about 40%, by weight on a dry fiber basis of the paper web structure. Fillers can be incorporated in a single layer sheet or in any layer of a multi-layer web product.

[0072] Strength additives - The process of the present application also includes adding strength additives to the papermaking furnish. Generally, the strength additives may be applied in various amounts depending on the desired properties of the web. Strength additives useful in the present disclosure include, but are not limited to, cationic water-soluble resins. These resins impart wet strength to the paper sheet and are well known in the papermaking art. Such resins include, but are not limited to, polyamide epichlorohydrin (PAE), urea-formaldehyde resins, melamine formaldehyde resins, polyacrylamide resins, dialdehyde starch, and mixtures thereof.

[0073] In some embodiments, other strength agents may be utilized to further improve the strength of the fibrous web product. The list of optional chemical components is intended to be merely exemplary in nature and is not meant to limit the scope of the present disclosure. Other materials are also contemplated as long as they do not interfere with or negate the advantages of the present disclosure.

[0074] The fibrous structure may include at least two plies arranged in contact in a facing relationship. Each of the at least two plies may include at least two layers all arranged in a facing relationship. Each of the at least two layers in each ply may include structural fibers selected from the group consisting of softwood fibers, non-wood fibers, man-made cellulose or non-cellulose fibers, hardwood fibers, recycled fibers, and mixtures thereof. Each multi-layer ply may include a surface layer comprising cellulose nanoparticles. The fibrous structure may bond the plies such that the surface layer of each ply becomes the surface layer of the fibrous structure as discussed above. The surface layer may comprise more than about 40 weight percent of the cellulose nanoparticles of the surface layer. The cellulose nanoparticles may be applied to the surface layer of the first ply by the process described above before placing the first ply in contact in a facing engagement with a surface of a second ply of the at least two plies. Additionally, the cellulose nanoparticles may be applied to create a surface layer comprising cellulose nanofilaments.

[0075] Any dimension and / or value disclosed herein should not be understood to be strictly limited to the exact numerical value recited. Instead, unless otherwise specified, each such dimension and / or value is intended to mean both the recited dimension and / or value, as well as a functionally equivalent range surrounding that dimension and / or value. For example, a dimension disclosed as "40 mm" is intended to mean "about 40 mm."

[0076] All documents cited herein, including cross-referenced or related patents or applications, and patent applications or patents to which this application claims priority or benefit, are incorporated herein by reference in their entirety unless expressly excluded or otherwise limited. The citation of a document is not an admission that it is prior art to any invention disclosed or claimed herein, or that it alone, or in combination with other reference(s), teaches, suggests, or discloses such invention. Furthermore, to the extent that a meaning or definition of a term in this document conflicts with a 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.

[0077] While particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended in the appended claims to cover all such changes and modifications that are within the scope of this invention. Preferred embodiments of the present invention are described below. [1] A fibrous structure comprising at least two layers, each of the at least two layers comprising a blend of structural fibers selected from the group consisting of softwood fibers, non-wood fibers, natural non-cellulosic fibers, man-made cellulose or non-cellulosic fibers, hardwood fibers, recycled fibers, and mixtures thereof, arranged in facing relationship, and a second layer of the at least two layers comprising between about 0.05 weight percent and about 20 weight percent cellulose nanoparticles of the second layer. [2] The fiber structure described in [1], wherein a first layer of the at least two layers contains about 0.05 weight percent to about 20 weight percent cellulose nanoparticles of the second layer. [3] The fiber structure described in [2], wherein the first layer contains cellulose nanoparticles of a weight different from the weight of the cellulose nanoparticles disposed in the second layer. [4] The fiber structure described in [1], wherein a first layer of the at least two layers does not contain intentionally added cellulose nanoparticles. [5] The fibrous structure of [1], wherein a first layer of the at least two layers is formed in contact with a forming surface of a papermaking machine during manufacture. [6] The fiber structure described in [1], wherein the second layer contains about 0.1 weight percent to about 5 weight percent of the cellulose nanoparticles of the second layer. [7] The fiber structure described in [1], wherein the cellulose nanoparticles include high aspect ratio nanofilaments. [8] A fiber structure comprising a surface layer comprising high aspect ratio nanofilaments. [9] The fiber structure described in [8], wherein the surface layer comprises at least about 40 weight percent of the high aspect ratio nanofilaments of the surface layer.

[10] The fiber structure described in [8], wherein the surface layer comprises more than about 50 weight percent of the high aspect ratio nanofilaments of the surface layer.

[11] A fibrous structure comprising at least two plies arranged in contact with each other in an opposed relationship having a longitudinal grain and a transverse and coplanar longitudinal grain, each of the at least two plies comprising a mixture of structural fibers selected from the group consisting of softwood fibers, non-wood fibers, natural non-cellulosic fibers, man-made cellulose or non-cellulosic fibers, hardwood fibers, recycled fibers, and mixtures thereof, wherein a first of the at least two plies comprises a first layer, the first layer comprising between about 0.05 weight percent and about 20 weight percent of cellulose nanoparticles of the first layer.

[12] The fiber structure of

[11] , wherein the first ply further comprises a second layer, the second layer not containing intentionally added cellulose nanoparticles.

[13] The fiber structure of

[11] , wherein the first ply includes a second layer, the second layer including a weight of cellulose nanoparticles different from a weight of cellulose nanoparticles disposed in the first layer.

[14] The fiber structure of

[11] , wherein the first ply includes a second layer, the second layer including cellulose nanoparticles in a weight amount equal to the weight of the cellulose nanoparticles disposed in the first layer.

[15] The fiber structure of

[11] , further comprising a second ply, the second ply comprising a first layer, the first layer of the second ply comprising about 0.05 weight percent to about 20 weight percent cellulose nanoparticles of the second layer of the second ply.

[16] The fiber structure of

[15] , wherein the second ply includes a second layer, the second layer of the second ply including a weight of cellulose nanoparticles different from a weight of cellulose nanoparticles disposed in the first layer of the second ply.

[17] The fiber structure of

[15] , wherein the second ply further comprises a second layer, and the second layer of the second ply does not contain intentionally added cellulose nanoparticles.

[18] The fiber structure of

[15] , wherein the second ply includes a second layer, the second layer of the second ply including a weight of cellulose nanoparticles different from a weight of cellulose nanoparticles disposed in the first layer of the second ply.

[19] The fiber structure of

[15] , wherein the second ply includes a second layer, the second layer of the second ply including a weight of cellulose nanoparticles equal to a weight of cellulose nanoparticles disposed in the first layer of the second ply.

Claims

1. A textile structure having wales and crosses, the cross grain of the textile structure is perpendicular to and coplanar with the longitudinal grain of the textile structure; the fibrous structure includes a first ply and a second ply disposed in contacting facing relationship; each of the first ply and the second ply comprises a mixture of structural fibers selected from the group consisting of softwood fibers, non-wood fibers, natural non-cellulosic fibers, man-made cellulose or non-cellulosic fibers, hardwood fibers, recycled fibers, and mixtures thereof; the first ply comprises a first layer and a second layer, the first layer of the first ply comprising cellulose nanoparticles in an amount between 0.05 weight percent and 20 weight percent of the first layer; the second layer of the first ply comprises a weight of the cellulose nanoparticles different from a weight of the cellulose nanoparticles disposed in the first layer of the first ply; Textile structures.

2. 10. The fibrous structure of claim 1, wherein the first ply further comprises a third layer that is free of intentionally added cellulose nanoparticles.

3. 2. The fibrous structure of claim 1, wherein the first ply further comprises a third layer comprising cellulose nanoparticles in a weight amount equal to a weight amount of the cellulose nanoparticles disposed in the first layer of the first ply.

4. 2. The fibrous structure of claim 1, wherein the second ply of the fibrous structure comprises a first layer and a second layer, and the first layer of the second ply comprises the cellulose nanoparticles in an amount of 0.05 weight percent to 20 weight percent of the first layer of the second ply.

5. 5. The fibrous structure of claim 4, wherein the second layer of the second ply comprises the cellulose nanoparticles in a weight different than a weight of the cellulose nanoparticles disposed in the first layer of the second ply.

6. 5. The fibrous structure of claim 4, wherein the second layer of the second ply is free of intentionally added cellulose nanoparticles.

7. 5. The fibrous structure of claim 4, wherein the second layer of the second ply comprises the cellulose nanoparticles in a weight different than a weight of the cellulose nanoparticles disposed in the first layer of the second ply.

8. 5. The fibrous structure of claim 4, wherein the second layer of the second ply comprises a weight of the cellulose nanoparticles equal to a weight of the cellulose nanoparticles disposed in the first layer of the second ply.

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