JP2015511278A - Fibrous structure and method for producing the same - Google Patents

Abstract

A fibrous structure containing a plurality of solid additives and a plurality of filaments is provided.

Description

  The present invention relates to a fibrous structure, more specifically a fibrous structure comprising a plurality of solid additives and a plurality of filaments, and even more specifically a fiber comprising a plurality of solid additives and a plurality of starch filaments. The present invention relates to a fibrous structure and a method for producing such a fibrous structure.

  Fibrous structures comprising solid additives such as pulp fibers and filaments such as starch filaments are known in the art. Such fibrous structures have been manufactured using filament sources such as melt blow dies. Traditionally, meltblowing dies have been oriented in the same way in the machine direction of the fibrous structure produced by the filaments supplied by such meltblowing dies. For example, meltblowing dies have been oriented at an angle of 90 ° to the machine direction. The problem of manufacturing fibrous structures with filament sources oriented in the same direction, eg, at an angle of 90 ° to the machine direction, such as meltblown dies, is the fibrous structure supplied by each filament source Each filament layer in the body has the same orientation as each other filament layer from each other filament source, as shown in FIG. FIG. 1 shows a fibrous structure 10 comprising three layers 12 of filaments 14, each layer 12 being manufactured with a filament source oriented at an angle of 90 ° to the machine direction, whereby each layer 12 of filaments 14. Indicates the orientation in the machine direction. As a result, a fibrous structure 10 containing three layers 12 of solid additives 16 (eg, pulp fibers) and filaments 14 exhibiting similar orientation was measured according to the dry tensile strength test method described herein. Sometimes an average tensile ratio greater than 2 is indicated. The effect of the filament layer exhibiting similar orientation is due to fibrous structures made at speeds greater than 1.01 m / sec (200 ft / min) and / or greater than 20 inches wide. Depending on the fibrous structure, it can be significant.

  In addition to the above, there is no solid additive, for example, no pulp fibers, from thermoplastic polymer filaments produced by spunbond dies and / or meltblown dies oriented at an angle different from the machine direction of the fiber structure It is known in the art to produce fibrous structures.

  Thus, a fibrous structure comprising a plurality of solid additives (eg, pulp fibers) and a plurality of filaments (eg, starch filaments), wherein the filaments are in two or more layers based on the orientation of the filaments themselves in each layer. There is a need for fibrous structures that exist in different layers of fibrous structures, as well as methods for making such fibrous structures.

  The present invention satisfies the above needs by providing a novel fibrous structure comprising a plurality of solid additives (eg, pulp fibers) and a plurality of filaments (eg, starch filaments).

  In one example of the present invention, a fibrous structure is provided that includes a plurality of solid additives and a plurality of filaments, wherein the filaments are based on the orientation of the filaments themselves in each layer, and the fibrous properties of two or more different filament layers. Present in the structure.

  In another example of the present invention, a fibrous structure comprising a plurality of filaments comprising one or more polysaccharides is provided, wherein the fibrous structure is a dry tensile strength test method as described herein. Shows a tensile ratio of 2 or less.

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

In yet another example of the present invention, a method for producing a fibrous structure,
a. Supplying a plurality of filaments from a filament source; and b. And a step of recovering the filament with a recovery device to form the fibrous structure so that the fibrous structure exhibits a tensile ratio of 2 or less when measured according to the tensile ratio test method described in the present specification. Is provided.

In still another embodiment of the present invention, there is provided a method for manufacturing a fibrous structure,
a. Supplying a first filament from a first source of filaments;
b. Supplying a second filament from a second source of filaments;
c. Optionally supplying additional filaments from an additional source of filaments;
d. Supplying a solid additive from a source of solid additive; and e. Recovering the first and second filaments (and any additional filaments) and solid additives to form a fibrous structure, wherein the first source of filaments is the fibrous structure machine A forming step is provided, wherein the second source of filaments is oriented at a first angle relative to the direction and oriented at a second angle relative to the machine direction that is different from the first angle.

  Accordingly, the present invention provides a fibrous structure and a method for producing a fibrous structure that satisfies the above needs.

It is the schematic of the conventional fibrous structure. 1 is a schematic view of an embodiment of a fibrous structure according to the present invention. FIG. 4 is an image of a filament layer of a fibrous structure produced by a filament source oriented at an angle of 90 ° with respect to the machine direction of the fibrous structure. FIG. 4 is an image of a filament layer of a fibrous structure produced by a filament source oriented at an angle of about 40 ° relative to the machine direction of the fibrous structure. 1 is a schematic view of an embodiment of a fibrous structure according to the present invention. FIG. 6 is a cross-sectional view of the fibrous structure of FIG. 5 taken along line 6-6. 1 is a schematic view of an embodiment of a method for producing a fibrous structure according to the present invention. 1 is a schematic view of a part of a manufacturing process of a fibrous structure according to the present invention. 1 is a schematic view of an embodiment of a melt blow die according to the present invention. It is the schematic of an example of the barrel of the twin-screw extruder by this invention. FIG. 10B is a schematic diagram of the screw and mixing component configurations for the twin screw extruder of FIG. 10A.

Definitions of Terms As used herein, a “fibrous structure” is a structure that includes one or more filaments (eg, a plurality of filaments) and one or more solid additives (such as a plurality of pulp fibers). Means. In one embodiment, the fibrous structure according to the present invention is a composite of filament and solid additive that together form a functionable structure.

  Non-limiting examples of manufacturing processes for fibrous structures according to the present invention include the known wet, solution and dry filament spinning processes typically referred to as nonwoven processing methods. In one example, the filament spinning process is a meltblowing process in which filaments are provided from a meltblowing die (filament source). Further processing of the fibrous structure can be performed such that the final fibrous structure is formed. For example, the final fibrous structure is a fibrous structure that is wound on a reel at the end of the fibrous structure manufacturing process. The final fibrous structure can then be converted into a final product such as a sanitary tissue product.

  As used herein, “filament” means an elongated microparticle whose length is significantly greater than its average diameter, ie, the ratio of length to average diameter is at least about 10. In one embodiment, the filament is a single filament rather than a spun yarn that is a filament strand twisted along the length of the filament. In one example, the filament exhibits a length of 5.08 cm or more and / or 7.62 cm or more and / or 10.16 cm or more and / or 15.24 cm or more.

  Filaments are typically considered to be continuous or substantially continuous in nature, particularly in fibrous structures where filaments are present. Filaments are relatively longer than fibers. Non-limiting examples of filaments include meltblown and / or spunbond filaments. Non-limiting examples of polymers that can be spun into filaments include natural polymers such as starch, starch derivatives, cellulose (eg, rayon and / or lyocell), cellulose derivatives, hemicellulose, and hemicellulose derivatives, and heat. Plastic polymer filaments such as polyester, nylon, polyolefins (eg, polypropylene filaments and polyethylene filaments), and biodegradable thermoplastic fibers such as polylactic acid filaments, polyhydroxyalkanoate filaments, polyesteramide filaments, and polycaprolactone filaments Synthetic polymers that are not limited to these.

  The filaments of the present invention may be single component and / or multicomponent. For example, the filament may comprise a bicomponent filament. The bicomponent filament may be in any form such as side-by-side, core and sheath, or sea-island type.

  As used herein, “solid additive” means solid particles such as powders, granules, and / or fibers.

  As used herein, “fiber” means elongated microparticles as described above that exhibit a length of less than 5.08 cm and / or less than 3.81 cm and / or less than 2.54 cm.

  The fibers are typically considered to be discontinuous in nature, especially in fibrous structures. Non-limiting examples of fibers include pulp fibers such as wood pulp fibers, and synthetic staple fibers such as polypropylene, polyethylene, polyester, copolymers thereof, rayon, glass fibers, and polyvinyl alcohol fibers.

  Staple fibers can be produced by spinning filament tows and then cutting the tows into segments of less than 5.08 cm to produce fibers.

  In one embodiment of the present invention, the fiber may be a natural material fiber, meaning that it is obtained from a natural material resource such as a plant resource (eg, a tree and / or plant). Such fibers are typically used in papermaking and are often referred to as papermaking fibers. Papermaking fibers useful in the present invention include cellulose fibers commonly known as wood pulp fibers. Applicable wood pulp includes, in addition to chemical pulp such as Kraft pulp, sulfite pulp, and sulfate pulp, for example, machines such as groundwood pulp, thermomechanical pulp, and chemically modified thermomechanical pulp. Pulp. However, chemical pulp may be preferred because it gives the tissue sheet produced from this excellent flexibility that can be touched. Pulp derived from both deciduous trees (hereinafter also referred to as “hardwood”) and conifers (hereinafter also referred to as “coniferous”) can be used. Hardwood and coniferous fibers can be blended or can be deposited in multiple layers to provide a layered web. Recycled paper-derived fibers are also applicable to the present invention, in addition to any or all of the above types of fibers, fillers, softeners, wet and dry strength improvements used to promote original papermaking Agents, as well as other non-fibrous polymers such as adhesives may be included.

  In addition to various wood pulp fibers, other cellulosic fibers such as cotton linters, rayon, lyocell, and bagasse fibers can be used in the fibrous structure of the present invention.

  In another example, the fibrous structure includes a solid additive that includes trichomes and / or seed hairs.

  As used herein, “filament layer” means a plurality of filaments that form at least a portion of a fibrous structure in which the filaments of the layer extend along a common main direction. In other words, the filaments of the layers exhibit a common main orientation. For example, the filaments of the layer exhibit a machine direction orientation. In another example, the filaments of the layer may exhibit an orientation different from the machine direction, for example, an orientation along an angle between the machine direction and the cross machine direction. In one embodiment, one or more filament layers can be integrated together, such as by deposition, to form a fibrous structure according to the present invention. In addition, the fibrous structure can include two or more different filament layers. For example, as seen in FIG. 2, the fibrous structure 10 includes a first layer 18 of filaments 14 that exhibits a machine direction orientation and a filament 14 that exhibits an orientation different from the machine direction orientation exhibited by the first layer 18. Of the second layer 20.

  As used herein with respect to the orientation of filaments within a filament layer, “orientation” means that the filaments within the layer extend along a common major direction. Although some filaments in the layer extend in the second direction, it is clear that most filaments in the layer extend in a common main direction and the common main direction can establish the orientation of the filaments in the layer. is there. As can be seen in FIG. 3, the filament layer exhibits a machine direction orientation. In FIG. 4, the filament layer is angled with respect to the machine direction of the layer. In another example, the angle of a filament source, such as a meltblowing die (relative to the machine direction of the fibrous structure to be fabricated) provides filaments in a filament layer produced from a filament source having a predetermined orientation. . Thus, two or more layers of filaments are produced from two or more filament sources (eg, melt blow dies) oriented at different angles to the machine direction (eg, within the range of 0 ° to ± 90 ° from MD) If so, filaments in two or more layers will exhibit different orientations by default.

  For purposes of measuring the orientation angle of a filament source, such as a meltblowing die, a smaller angle relative to the machine direction is measured and is considered as the orientation angle of the filament source. If the orientation angle of the filament source coincides with the machine direction, the orientation of the angle is 90 °.

  As used herein, “nonwoven substrate” means a web comprising one or more filament layers of the present invention.

  As used herein, “sanitary tissue product” refers to wipes for wiping after urination and after defecation (toilet paper), wipes for excrement from otolaryngology (tissue paper), and multifunctional It means a fibrous structure useful as a wiping tool (absorbent towel) for absorbing and wiping. The sanitary tissue product may be wound on itself around the core or without the core so as to form a roll of sanitary tissue product.

  In one embodiment, the sanitary tissue product of the present invention comprises one or more fibrous structures according to the present invention.

The sanitary tissue product of the present invention has about 10 g / m ² to about 120 g / m ² , and / or about 15 g / m ² to about 110 g / m ² , and / or about 20 g / m ² to about 100 g / m ² , And / or a basis weight of about 30-90 g / m ² . In addition, the sanitary tissue product of the present invention can have from about 40 g / m ² to about 120 g / m ² , and / or from about 50 g / m ² to about 110 g / m ² , and / or from about 55 g / m ² to about 105 g / m. ² and / or a basis weight of about 60-100 g / m ² .

The density of the sanitary tissue product of the present invention is less than about 0.60 g / cm and / or less than about 0.30 g / cm ³ and / or less than about 0.20 g / cm ³ and / or about 0.10 g / cm. less than cm ^3, and / or less than about 0.07 g / cm ^3, and / or from about 0.05 g / cm less than ^3, and / or from about 0.01 g / cm ³ ~ about 0.20 g / cm ^3, and / or It may be from about 0.02 g / cm ³ to about 0.10 g / cm ³ .

  The sanitary tissue product of the present invention may be in the form of a roll of sanitary tissue product. Such a roll of sanitary tissue product may comprise a plurality of sheets of fibrous structures connected but perforated that can be removed from adjacent sheets.

  The sanitary tissue product of the present invention comprises additives such as softeners, temporary wet strength improvers, permanent wet strength improvers, bulk softeners, lotions, silicones, wetting agents, latex, patterned latex, and sanitary tissue Other types of additives suitable for inclusion in and / or on the product can be included.

As used herein, a “scrim” refers to a solid additive within the fibrous structure of the present invention such that the solid additive is disposed between the web material and another filament layer within the fibrous structure. By web material, such as web, containing filaments used to lay. In one embodiment, the scrim comprises a web material exhibiting a basis weight of less than 10 g / m ² and / or less than 7 g / m ² and / or less than 5 g / m ² and / or less than 3 g / m ² , layer remaining filaments of the fibrous structure shows a basis weight of 10 g / ^{m 2} ultrasonic and / or 15 g / ^{m 2} ultrasonic and / or 20 g / ^{m 2} ultrasonic and / or to about 120 g / ^{m 2.}

  As used herein, a “hydroxy polymer” includes any hydroxy-containing polymer from which the filaments of the present invention can be made. In one example, the hydroxy polymer of the present invention comprises more than 10% by weight and / or more than 20% by weight and / or more than 25% by weight hydroxyl moieties. In another example, the hydroxy-containing polymer is not part of a larger functional group, such as a carboxylic acid group.

  As used herein with respect to filaments as a whole filament and / or as a polymer within the filament, “non-thermoplastic” means that the filament and / or polymer is in the absence of a plasticizer such as water, glycerin, sorbitol, urea, etc. Means that under pressure, the filaments and / or polymers do not exhibit a melting point and / or softening point at which they can flow.

  “Thermoplastic” as used herein with respect to filaments as a whole filament and / or as a polymer within a filament causes the filament and / or polymer to flow under pressure in the absence of a plasticizer at a particular temperature. It is meant to indicate the melting point and / or softening point that becomes possible.

  As used herein, “non-cellulose containing” refers to less than 5% by weight and / or less than 3% by weight and / or less than 1% by weight and / or less than 0.1% by weight within the fiber component. , And / or 0% by weight of cellulose polymer, cellulose derivative polymer, and / or cellulose copolymer. In one example, “non-cellulose-containing” is less than 5% by weight and / or less than 3% by weight and / or less than 1% by weight and / or less than 0.1% by weight and / or 0% by weight. It means that the cellulose polymer is present in the fiber component.

  As used herein for filaments, “Associated”, “Associated”, “Association” and / or “Associating” are fibrous It means combining the filaments either directly or indirectly so that a structure is formed. In one example, the combined filaments can be joined together, for example, by adhesives and / or thermal bonds. In another example, the filaments can be composited together by being deposited on the same fibrous structure manufacturing belt.

  As used herein, “weight average molecular weight” refers to “Colloids and Surfaces A. Physico Chemical & Engineering Aspects”, 162, 2000, pages 107-121. Mean weight average molecular weight determined using gel permeation chromatography according to the protocol found.

  As used herein, “basis weight” is the weight per unit area of a sample, recorded in g / m.

  As used herein, “machine direction” or “MD” is parallel to the direction in which the fibrous structure flows through a fibrous structure making device, such as a papermaking device, and / or a sanitary tissue product making machine. Means direction.

  As used herein, “cross-machine direction” or “CD” means the direction perpendicular to the machine direction in the same plane of the fibrous structure and / or sanitary tissue product comprising the fibrous structure. To do.

  As used herein, a “ply” or “multi-ply” is an individual fibrous property that is arbitrarily placed in a substantially continuous face-to-face relationship with other layers to form a multilayer fibrous structure. Means a structure. It is also contemplated that a single fibrous structure can effectively form a two “ply” or multiple “plies”, eg, by folding on itself.

  As used herein, “spinneret” means a plate that includes one or more filament forming nozzles capable of discharging filaments of a molten composition. In one embodiment, the spinneret includes a plurality of filament forming nozzles arranged in one or more rows and / or columns. Such a spinneret is called a multiple row spinneret.

  As used herein with respect to two or more spinnerets adjacent to each other, “adjacent to each other” means that one spinneret surface is in contact with another spinneret surface.

  As used herein, “seam” means a line portion in contact between two adjacent spinnerets.

  As used herein, “seam filament forming nozzle opening” means one or more filament forming nozzle openings that are closest in distance to the seam formed by two spinnerets.

  As used herein, the articles “a” and “an” are used herein, for example, “an anionic surfactant” or “a fiber”. It is understood to mean that there is one or more of the claimed or described substance.

  All percentages and ratios are calculated by weight unless otherwise indicated. All percentages and ratios are calculated based on the total composition unless otherwise indicated.

  Unless otherwise stated, all component or composition concentrations relate to the activity level of the component or composition and exclude impurities that may be present in commercial sources, such as residual solvents or by-products. Is done.

Filament In one example, the fibrous structure of the present invention comprises a filament comprising a hydroxy polymer. In another example, the fibrous structure can include starch and / or starch-derived filaments. The starch filament may further comprise polyvinyl alcohol and / or other polymers.

  The filaments of the present invention can also be made from a polymer melt composition comprising a hydroxy polymer such as uncrosslinked starch, a crosslinking system comprising a crosslinking agent such as imidazolidinone, and water. The polymer melt composition may also include a surfactant, such as a sulfosuccinate surfactant. Non-limiting examples of suitable sulfosuccinate surfactants include Aerosol® AOT (dioctyl sodium sulfosuccinate) and / or Aerosol® MA-commercially available from Cytec Industries (Woodland Park, NJ). 80 (sodium dihexyl sulfosuccinate).

  In one embodiment, the filaments of the present invention comprise more than 25% and / or more than 40% and / or more than 50% and / or more than 60% and / or more than 70% to about 95% and / or to about 90% and And / or to about 80% hydroxy polymer filaments such as starch that may be in a crosslinked state. In one example, the filament comprises ethoxylated starch that can be in a crosslinked state and starch diluted with acid.

  In addition to the hydroxy polymer, the filament may comprise 0% and / or 0.5% and / or 1% and / or 3% to about 15% and / or about 12% by weight of the filament and Polyvinyl alcohol can also be included at about 10% by weight and / or about 7% by weight.

  The filament may contain a surfactant, such as a sulfosuccinate-based surfactant, at 0% and / or about 0.1% and / or from about 0.3% to about 2% and / or by weight of the filament. About 1.5 wt% and / or about 1.1 wt% and / or about 0.7 wt% may also be included.

  The filament may be selected from the group consisting of polyacrylamide and derivatives thereof; polyacrylic acid, polymethacrylic acid, and esters thereof; polyethyleneimine; a copolymer made from a monomer mixture of the polymer; and a mixture thereof, 0% by weight and / or about 0.01% by weight and / or about 0.05% by weight and / or about 0.5% by weight and / or about 0.3% by weight and / or about It may be included at about 0.2% by weight. Such polymers can exhibit a weight average molecular weight greater than 500,000 g / mol. In one example, the filament comprises polyacrylamide.

  The filaments may be in a cross-linked state with a cross-linking agent such as imidazolidinone (cross-linking the hydroxy polymer present in the filaments) to about 0.5% and / or about 1% by weight of the weight of the filament and / or Or about 2% and / or about 3% and / or about 10% and / or about 7% and / or about 5.5% and / or about 4.5% It can also be included. In addition to the cross-linking agent, the filament may contain a cross-linking accelerator that aids the cross-linking agent, 0% and / or about 0.3% and / or about 0.5% and / or about 2% by weight of the filament. % And / or about 1.7 wt% and / or about 1.5 wt%.

  The filament may also include a variety of other ingredients such as propylene glycol, sorbitol, glycerin, and mixtures thereof.

Polymers The filaments of the invention that when combined form the fibrous structure of the invention may contain various types of polymers such as hydroxy polymers, non-thermoplastic polymers, thermoplastic polymers, and mixtures thereof. .

  Non-limiting examples of hydroxyl polymers according to the invention include polyols such as polyvinyl alcohol, polyvinyl alcohol derivatives, polyvinyl alcohol copolymers, starch, starch derivatives, starch copolymers, chitosan, chitosan derivatives, chitosan copolymers, cellulose, cellulose derivatives. For example, cellulose ether and ester derivatives, cellulose copolymers, hemicellulose, hemicellulose derivatives, hemicellulose copolymers, gums, arabinans, galactans, proteins and various other polysaccharides, and mixtures thereof.

  In one example, the hydroxy polymer of the present invention is a polysaccharide.

  In other embodiments, the hydroxy polymer of the present invention is a non-thermoplastic polymer.

  The hydroxyl polymer can be from about 10,000 g / mol to about 40,000,000 g / mol, and / or more than about 100,000 g / mol, and / or more than about 1,000,000 g / mol, and / or Alternatively, a weight average molecular weight greater than about 3,000,000 g / mol and / or greater than about 3,000,000 g / mol and up to about 40,000,000 g / mol may be exhibited. Higher and lower molecular weight hydroxy polymers may be used in conjunction with hydroxyl polymers having a weight average molecular weight within a particular desired range.

  Well known modifications of hydroxyl polymers such as natural starch include chemical and / or enzymatic modifications. For example, native starch can be partially degraded by acid, hydroxyethylated, hydroxypropylated, and / or oxidized. Further, the hydroxy polymer may comprise dent corn starch hydroxy polymer.

  The polyvinyl alcohol herein can be grafted with other monomers to modify its properties. A wide range of monomers have been successfully grafted to polyvinyl alcohol. Non-limiting examples of such monomers include vinyl acetate, styrene, acrylamide, acrylic acid, 2-hydroxyethyl methacrylate, acrylonitrile, 1,3-butadiene, methyl methacrylate, methacrylic acid, vinylidene chloride, vinyl chloride, vinylamine and various Examples include acrylate esters. Polyvinyl alcohol includes a variety of hydrolysates formed from polyvinyl acetate. In one example, the degree of hydrolysis of polyvinyl alcohol is greater than 70% and / or greater than 88% and / or greater than 95% and / or greater than about 99%.

  As used herein, “polysaccharide” means natural polysaccharides and polysaccharide derivatives or modified polysaccharides. Suitable polysaccharides include, but are not limited to starch, starch derivatives, chitosan, chitosan derivatives, cellulose, cellulose derivatives, hemicellulose, hemicellulose derivatives, gums, arabinans, galactans, and mixtures thereof. The water-soluble polysaccharide is from about 10,000 g / mol to about 40,000,000 g / mol, and / or more than about 100,000 g / mol, and / or more than about 1,000,000 g / mol, and A weight average molecular weight greater than about 3,000,000 g / mol and / or greater than about 3,000,000 g / mol and up to about 40,000,000 g / mol may be exhibited.

  Non-cellulosic copolymer hydroxypolymers such as non-cellulose and / or non-cellulose derivatives and / or non-cellulose polysaccharides are from starch, starch derivatives, chitosan, chitosan derivatives, hemicelluloses, hemicellulose derivatives, gums, arabinans, galactans, and mixtures thereof. Can be selected from the group consisting of

  In one example, a filament of the present invention without a thermoplastic water-insoluble polymer.

Solid additive The solid additive of this invention is applicable to the filament layer surface of a solid form. In other words, the solid additive of the present invention has no liquid phase, i.e., without melting the solid additive, and without suspending the solid additive in a liquid excipient or base. It can be delivered directly to the filament layer surface. As such, the solid additive of the present invention does not require a liquid phase or liquid excipient or base to deliver to the surface of the filament layer. The solid additive of the present invention can also be delivered via a gas or gas mixture. For clarity, in one embodiment, the solid additive is an additive that does not take the shape of a container when placed inside the container.

  In one embodiment, one or more solid additives may be present on the surface of the fibrous structure of the present invention.

  The solid additives of the present invention may have different geometries and / or cross-sectional areas containing spheres, ovals, stars, rectangles, trilobes, and various other eccentric shapes.

  In one embodiment, the solid additive is a particle of less than 6 mm and / or less than 5.5 mm and / or less than 5 mm and / or less than 4.5 mm and / or less than 4 mm and / or less than 2 mm of the maximum dimension of the solid additive. Can show shape.

  The solid additive of the present invention may exhibit an aspect ratio of less than about 25/1 and / or less than about 15/1 and / or less than about 10/1 and / or 5/1 to less than about 1/1. The particles are not fibers as defined herein.

Solid additives may be present in the fibrous structures of the present invention in greater than about 1 and / or greater than about 2 and / or greater than about 4 and / or to about 20 and / or to about 15 and / or to about 10 g / m. You may make it exist at about ² . In one example, the fibrous structure of the present invention comprises about 2 to about 10 and / or about 5 to about 10 g / m ² of solid additive.

  In one example, the solid additive is in the fibrous structure of the present invention greater than 5%, and / or greater than 10%, and / or greater than 20% to about 50%, and / or greater than about 40%. And / or present to the extent of greater than about 30%.

  In one example, the solid additive 14 includes fibers, such as wood pulp fibers. The wood pulp fibers may be softwood pulp fibers and / or hardwood pulp fibers. In one embodiment, the wood pulp fibers are Eucalyptus pulp fibers. In another example, the wood pulp fiber comprises Southern Softwood Kraft (SSK) pulp fiber.

  The solid additive may be, for example, chemically treated, for example, chemically treated pulp fiber. In one example, the solid additive includes a softener and / or the surface is treated with the softener. Non-limiting examples of suitable softeners include silicones and / or quaternary ammonium compounds, such as PROSOFT® available from Hercules Incorporated. In one example, the solid additive includes, by way of example, wood pulp treated with a quaternary ammonium compound softening agent available from Georgia-Pacific Corporation. One advantage of adding a softening agent only to a solid additive compared to applying a softening agent and / or joining materials throughout a fibrous structure and / or nonwoven substrate is: Compared to other components including the entire fibrous structure that does not need to be softened, the constituent elements of the entire fibrous structure that need to be softened are reliably softened by the softening agent.

Nonwoven fabric substrate The nonwoven fabric substrate of the present invention comprises one or more filament layers. Two or more filament layers made from a nonwoven substrate can have the same or different orientations. In one example, the nonwoven substrate includes two or more filament layers that exhibit different orientations.

In one example, the nonwoven substrate includes a plurality of filaments comprising a hydroxy polymer. The hydroxy polymer may be selected from the group consisting of polysaccharides, derivatives thereof, polyvinyl alcohol, derivatives thereof, and mixtures thereof. In one example, the hydroxy polymer comprises starch and / or starch derivatives. The nonwoven substrate 12 may be greater than about 10 g / m ² and / or greater than about 14 g / m ² and / or greater than about 20 g / m ² and / or greater than about 25 g / m ² and / or greater than about 30 g / m ² and / or Alternatively, a basis weight of greater than about 35 g / m ² and / or greater than about 40 g / m ² and / or less than about 100 g / m ² and / or less than about 90 g / m ² and / or about 80 g / m ² may be exhibited.

Fibrous Structure As shown in FIGS. 5 and 6, in one embodiment, the fibrous structure 10 of the present invention includes one or more filament layers, one or more joining sites for the nonwoven substrate 26 and the nonwoven substrate 26. 30 includes a nonwoven substrate 26 comprising a plurality of solid additives 16 such as pulp fibers disposed between a scrim 28 joined at 30. The bonding site 30 is at least a portion of the scrim 28, either through thermal bonding or through bonding produced by applying high pressure to both the scrim 28 and the nonwoven substrate 26 so that a glass transition effect (“pressure bonding”) occurs. And it is a site | part which connects a part of nonwoven fabric base material 26 mutually.

  In one example, the solid additive 16 can be uniformly distributed on the surface 32 of the nonwoven substrate 26.

In one embodiment, scrim 28 includes one or more filament layers of the present invention. In one embodiment, scrim 28 comprises a filament monolayer of the present invention. The scrim 28 and the nonwoven substrate 26 can also include filaments having similar compositions, such as hydroxy polymer-containing filaments, such as starch filaments. The scrim 28 is greater than 0.1 and / or greater than 0.3 and / or greater than 0.5 and / or greater than 1 and / or less than 2 g / m ² and / or less than 10 and / or less than 7 and / or less than 5. And / or can be present in the fibrous structure of the present invention at a basis weight of less than 4 g / m ² . In one example, the scrim 28 can be present in the fibrous structure of the present invention at a basis weight of about 0.1 to about 4 g / m ² .

  One purpose of the scrim 28 is to reduce lint produced by the fibrous structure 10 by preventing the solid additive 16 from separating from the fibrous structure 10. The scrim 28 can provide additional strength characteristics to the fibrous structure 10.

  As seen in FIGS. 5 and 6, the junction site 30 may include a plurality of separate junction sites. Separate junction sites can also exist in the form of non-random repeating patterns. One or more bonding sites 30 may include thermal bonding and / or pressure bonding.

  In one embodiment, the fibrous structure of the present invention comprises a plurality of filaments, such as hydroxy polymer-containing filaments, wherein the filaments are two or more different filament layers based on the orientation of the filament itself in each layer of the fibrous structure. Present in.

  Unexpectedly, the fibrous structure of the present invention has 2 or less and / or less than 1.7 and / or less than 1.5 and / or when measured according to the dry tensile strength test method described herein. Or an average tensile ratio (MD tensile strength / CD tensile strength) of less than 1.3 and / or greater than 1.1 and / or greater than 0.7 and / or greater than 0.9. In one example, the fibrous structure of the present invention exhibits an average tensile ratio of about 0.9 to about 1.1 as measured according to the dry tensile strength test method described herein.

  Table 1 below shows examples of the tensile ratio of the fibrous structure of the present invention and the comparative fibrous structure.

  The fibrous structure of the present invention may contain a surface softening agent. The surface softening agent can also be applied to the surface of the fibrous structure. The softening agent can also include silicone and / or quaternary ammonium compounds.

  The fibrous structure of the present invention may include embossing so that the fibrous structure is in an embossed state.

  In one example, the fibrous structure is bonded to each nonwoven substrate surface with a nonwoven substrate having a plurality of solid additives present on both sides of the nonwoven substrate disposed between the nonwoven substrate surfaces. One or more scrims. The solid additives can be different or the same, can be present in different or the same degree, and can be evenly distributed on the opposite surface of the nonwoven substrate. The scrims can be different or the same, can be present in different or the same degree, and can be joined to one or more joining sites on the opposite side of the nonwoven substrate.

  In another example, the fibrous structure of the present invention can include a single ply within a multi-ply sanitary tissue product.

  In another example, a multi-ply sanitary tissue product is provided that includes two or more plies of fibrous structure according to the present invention. In one embodiment, two or more plies of a fibrous structure according to the present invention are integrated to form a multilayer sanitary tissue product. The two or more plies can be integrated such that the solid additive is adjacent to at least one outer surface and / or each outer surface of the multi-ply sanitary tissue product.

Manufacturing Method of Fibrous Structure FIGS. 7 and 8 illustrate an example of the manufacturing method of the fibrous structure of the present invention. As seen in FIGS. 7 and 8, the method 34 comprises:
a. Supplying a first filament 36 from a first filament supply source 38 to form a first filament layer 40;
b. Supplying a second filament 42 from a second filament supply source 44 to form a second filament layer 46;
c. Supplying a third filament 48 from a third filament supply source 50 to form a third filament layer 52;
d. Supplying the solid additive 16 from a source 54 of solid additive; and e. Supplying a fourth filament 56 from a fourth filament supply source 58 to form a fourth filament layer 60; and f. Recovering the first, second, third, and fourth filaments 36, 42, 48, 56 and the solid additive 16 to provide the fibrous structure 10, the first source of filaments 38 is oriented at a first angle α relative to the machine direction of the fibrous structure 10, and the second source 44 of filaments is oriented at a second angle β that is different from the first angle α relative to the machine direction. The third source 50 is oriented at a third angle δ different from the first angle α and the second angle β with respect to the machine direction, and the fourth source 58 is second with respect to the machine direction. Orienting at a fourth angle ε different from the third angle δ and the third angle δ.

  The first, second, and third filament layers 40, 46, 52 are collected by a collection device 62, which can be a belt or a fabric. The collection device 62 may be a belt patterned to impart a pattern such as a non-random type or a repetitive pattern to the fibrous structure 10 during the fibrous structure manufacturing process. The first, second, and third filament layers 40, 46, 52 are recovered by a recovery device 62 (eg, recovering one layer on top of another layer) and depositing the solid additive 16. A nonwoven fabric base 26 is formed. Next, the fourth filament layer 60 may be deposited on the solid additive 16 to form the scrim 28.

  The first angle α and the fourth angle ε may be the same angle, for example, 90 ° with respect to the machine direction.

  The second angle β and the third angle δ may be the same angle that is just positive and negative with respect to each other. For example, the second angle β may be −40 ° with respect to the machine direction and the third angle δ may be + 40 ° with respect to the machine direction.

  In one embodiment, at least one of the first, second, and third angles α, β, δ is less than 90 ° with respect to the machine direction. In another example, the first angle α and / or the fourth angle ε is about 90 ° with respect to the machine direction. In yet another example, the second angle β and / or the third angle δ is from about ± 10 ° to about ± 80 ° and / or from about ± 30 ° to about ± 60 ° relative to the machine direction. And / or about ± 40 ° with respect to the machine direction.

  In one example, the first, second, and third filament layers 40, 46, 52 may be formed on the nonwoven substrate 28 prior to use in the fibrous structure manufacturing process described above. In this case, the nonwoven substrate 28 is similar to the parent roll that can be unwound in the fibrous structure manufacturing process, and the solid additive 16 can be deposited directly on the surface 32 of the nonwoven substrate 28.

  In one example, supplying the plurality of solid additives 16 onto the nonwoven substrate 26 may include airlaid the solid additives 16 using an airlaid device. A non-limiting example of a suitable airlaid device is available from Dan-Web (Aarhus, Denmark).

  In one embodiment, supplying the fourth filament 56 such that the filament is in contact with the solid additive 16 is such that at least a portion (all or substantially all in one example) of the solid additive 16 is caused by the fourth filament 56. Contacting and depositing the fourth filament 56 such that the solid additive 16 is disposed between the fourth filament layer 60 of filaments and the nonwoven substrate 26. If the fourth filament layer 60 of the filament is disposed at a predetermined position, the fourth filament layer 60 (in this case, the scrim 28) is joined to the nonwoven fabric substrate 26 in the filamentous fibrous structure 10. It can be performed. This joining process may include a thermal joining operation. The thermal bonding operation may include passing the fibrous structure 10 through a nip formed by the thermal bonding rolls 64, 66. At least one of the thermal bonding rolls 64, 66 may include a pattern that has been converted to a bonding site 30 formed in the fibrous structure 10.

  In addition to performing a joining operation, the fibrous structure is passed through a nip formed between two engaging gear rolls, humidified, free fiber ends are created, and surface treatment is performed to produce the final fibrous structure. Other post-treatments can also be performed on the fibrous structure, including embossing, tufting, gear roll processing, including forming. In one embodiment, the fibrous structure can be subjected to gear roll processing by passing the fibrous structure through a nip formed by at least a pair of gear rolls. In one example, the fibrous structure is gear rolled so that free fiber ends are produced in the fibrous structure. Gear roll processing may be performed before or after two or more fibrous structures are integrated to form a multi-ply sanitary tissue product. When gear roll processing is performed later, the multi-ply sanitary tissue product is passed through a nip formed by at least a pair of gear rolls.

  The manufacturing method of the fibrous structure of the present invention may be intimately coupled with a conversion operation to perform embossing, printing, deformation, surface treatment, or other post-forming operations known to those skilled in the art ( In this case, the fibrous structure may be rolled into a roll before proceeding to the conversion operation, or may be directly connected (in this case, the fibrous structure is Do not roll into a ring). For the purposes of the present invention, direct connection means that the fibrous structure can proceed directly to the conversion work, for example, after being wound around the roll in a convoluted manner and then unwound to proceed to the conversion work. Means.

  In one embodiment, one or more plies of a fibrous structure according to the present invention may be integrated with another fibrous structure ply, which may also be a fibrous structure according to the present invention. 2 or less and / or less than 1.7 and / or less than 1.5 and / or less than 1.3 and / or more than 1.1 and / or more than 0.7 when measured according to the dry tensile strength described in And / or a multi-ply sanitary tissue product exhibiting a tensile ratio of 0.9 can also be formed. In one example, a multi-ply sanitary tissue product can also be formed by joining two or more plies of a fibrous structure according to the present invention. In another example, two or more plies of a fibrous structure according to the present invention are integrated so that a solid additive present in the fibrous structure ply is adjacent to each outer surface of a multi-ply sanitary tissue product. A multi-ply sanitary tissue product can also be formed.

  The method of the present invention may comprise the steps of producing a fibrous structure suitable for use by consumers and / or individual rolls of sanitary tissue products comprising such fibrous structure.

  In one embodiment, the filament source includes a meltblowing die that produces filaments from a polymer melt composition according to the present invention. In one embodiment, as seen in FIG. 9, the meltblowing die 68 includes at least one filament forming hole 70 for spinning filaments and / or two or more rows and / or three or more rows of filament forming holes 70. obtain. At least one row of filament formation holes 70 contains two or more and / or three or more and / or ten or more filament formation holes 70. In addition to the filament formation hole 70, the meltblowing die 68 includes a fluid discharge hole 72, such as a gas discharge hole (in one embodiment, an air discharge hole that narrows the filament formed from the filament formation hole 70). One or more fluid discharge holes 72 are associated with the filament formation holes so that the fluid discharged from the fluid discharge holes 72 is angled with respect to the outer surface of the filament exiting the filament formation holes 70 (like a knife edge die). (But not parallel) or parallel. In one embodiment, the fluid discharged from the fluid discharge holes 72 is less than 30 ° and / or less than 20 ° and / or less than 10 ° and / or 5 ° on the outer surface of the filament formed from the filament forming hole 70 and / or Or contact at an angle of about 0 °. One or more fluid discharge holes 72 may be disposed around the filament formation hole 70. In one embodiment, one or more fluid discharge holes 72 are associated with a single filament formation hole 70 so that fluid discharged from the one or more fluid discharge holes 72 is the single filament formation hole 70. In contact with the outer surface of a single filament formed from 70. In one embodiment, fluid discharge holes 72 allow a fluid, such as a gas, such as air, to be formed from filament forming holes 70 rather than contacting the inner surface of the filaments as occurs when forming hollow filaments. Allow contact with the outer surface of the filament.

Synthesis of Polymer Melt Composition The polymer melt composition of the present invention can be produced by a screw extruder such as a vented twin screw extruder.

APV Baker (Peterborough, England) 40 : outlining barrel 74 in FIG. 10A of 1,48Mm ^2-screw extruder. Barrel 74 is divided into eight regions shown as regions 1-8. Barrel 74 surrounds the extrusion screw and mixing components outlined in FIG. 10B and is provided as a containment vessel during the extrusion process. A solid supply port 76 is disposed in region 1 and a liquid supply port 78 is disposed in region 1. Vent 80 is included in region 7 to cool and reduce the components of the mixture prior to exiting the extruder, for example a liquid such as water. A commercially available bent stuffer from APV Baker can be employed if desired to prevent the polymer melt composition from being discharged from the vent 80. The polymer melt composition stream through barrel 74 flows from region 1 and exits barrel 74 at region 8.

  The configuration of the screw and mixing components of the twin screw extruder is outlined in FIG. 10B. As shown in Table 2 below, the twin screw extruder has a plurality of double screw (TLS) (indicated as A and B), paddle (indicated as C), and reverse double screw (RTLS) (indicated as D). ) Are arranged in series.

  The screw component (A-B) is characterized by the number of consecutive leads and the pitch of these leads. The lead is a flight (with a predetermined helix angle) that surrounds the core of the screw component. The number of leads means the number of flights surrounding the core at a predetermined position along the length of the screw. Increasing the number of leads decreases the screw volume and increases the pressure generating capacity of the screw.

  The pitch of the screw is the distance required for one flight to complete one turn of the core. This is expressed as the number of screw component diameters per flight turn completed. Decreasing the screw pitch increases the pressure generated by the screw and reduces the screw volume.

  The length of the screw component is recorded as the ratio of the component length divided by the component diameter.

  This example uses TLS and RTLS. The A-type screw component is a TLS with 1.0 pitch and varying length ratio. The B-type screw component is a TLS with 0.5 pitch and varying length ratio.

  Also included is a Bilobal paddle, C, which is provided as a mixing component in series with the TLS and RTLS screw components for the purpose of enhancing mixing. Paddle C has a length ratio of 1/4. For the purpose of controlling the flow and the corresponding mixing time, various shapes of double-leaf paddles and counter-rotating screw components D (single and double-screws screwed in opposite directions) are used. Screw component D is an RTLS with 0.5 pitch and 0.5 length ratio.

  In region 1, hydroxy polymer is fed to the solid feed port using a K-Tron (Pitman, NJ) loss-in-weight feeder at a rate of 230 g / min. A Milton Roy (Ivyland, PA) diaphragm pump (7.2 L (1.9 gallons) / hour pump head) was used inside the extruder (zone 1) at a liquid feed rate of 146 g / min. Water, an external plasticizer and this hydroxy polymer are kneaded to form a hydroxy polymer / water slurry. Next, this slurry is fed into the barrel of an extruder and heat-treated. Table 3 below lists the temperature, pressure, and function corresponding to each area of the extruder.

  After the slurry is discharged from the extruder, some melt-processed hydroxy polymer is discarded, and the other part (100 g) is fed to PEP Type II Zenith® (Sanford NC), SMX static mixer Pump to (Koch-Glitsch, Woodridge, Illinois). Using a static mixer, additives such as crosslinkers, crosslink accelerators, external plasticizers (eg, water) are mixed with the melt processed hydroxypolymer. The additive is pumped to the static mixer by a PREP 100 HPLC pump (Chrom Tech, Apple Valley MN). These pumps provide additional performance at high pressure and low capacity. The polymer melt composition of the present invention can be processed at any time by a polymer processing operation.

Filament Synthesis A non-limiting example of a process for making filaments by polymer processing the polymer melt composition of the present invention. As used herein, “polymer processing” refers to any operation and / or process in which filaments containing a processed hydroxy polymer are formed from a polymer melt composition. Non-limiting examples of polymer processing operations include extrusion, molding and / or spinning. Extrusion and molding (either cast or blow molding) typically produces films, sheets, and extruded bodies of various properties. Molding can include injection molding, blow molding, and / or compression molding. Spinning can include spunbonding, meltblowing, rotary spinning, continuous filament manufacturing and / or tow fiber manufacturing. As used herein, “processed hydroxy polymer” means any hydroxy polymer that has undergone a polymer processing operation after a melt processing operation.

  An example of a process for producing the filament of the present invention from the polymer melt composition of the present invention is shown below.

The polymer melt composition is produced according to the polymer melt composition synthesis method described above. Using a suitable pump, such as a Zenith® PEPII type manufactured by Parker Hannifin Corporation (Zenith Pumps Department (Sanford, NC, USA)) and having a capacity of 10 cm ³ (cc / rev) per revolution, The polymer melt composition present in the twin screw extruder is pumped to a meltblowing die. The flow of hydroxy polymer, such as starch, to the meltblowing die is controlled by adjusting the number of revolutions per minute (rpm) of the pump. The extruder, pump, melt blow die, and optionally pipes connected to the mixer are electrically heated and controlled at 65 ° C. by a thermostat.

  The meltblowing die has a plurality of rows of circular extrusion nozzles spaced from each other at a pitch P of about 2.489 mm. The nozzles are arranged in a staggered grid, spaced approximately 2.489 mm within the rows and 2.159 mm between the rows. The nozzles 200 each have an inner diameter of about 0.254 mm and each have an outer diameter of about 0.813 mm. Each nozzle is surrounded by an annular opening formed in a perforated plate having a thickness of about 1.9 mm. The pattern of the plurality of openings in the perforated plate matches the pattern of the extrusion nozzle in the melt blow die. When the perforated plate is combined with a meltblowing die, the area obtained for air flow is about 36%. The plate is fixed so that the filaments extruded through the extrusion nozzle are surrounded by a generally cylindrical humidified air stream fed through the aperture of the perforated plate and become thinner. The extrusion nozzle can extend the outer surface of the perforated plate over a distance of about 1.5 mm to about 4 mm, and more specifically about 2 mm to about 3 mm. The two outer rows of extrusion nozzles on both sides of the plurality of extrusion nozzles are fitted together so that they are visible in a plane, and each of the boundary layer air openings is provided with the annular openings described above. An air opening is formed. In addition, all other rows of extrusion nozzles and all other columns are blocked, increasing the spacing between available extrusion nozzles.

  Filament reduction to heat compressed air with an electrical resistance heating device, for example a heating device manufactured by Chromalox (Emerson Electric division (Pittsburgh, PA, USA)) and to reduce the filament produced by the extrusion nozzle Converted air can be provided. Add a proper amount of steam with an absolute pressure of about 240 to about 420 kilopascals (kPa) controlled by a globe valve, saturate or almost saturate the heated air under the conditions of the transportation pipe controlled electrically and using a thermostat. Let The condensed water is removed in a separator that is electrically heated and thermostatically controlled. The reduced air has an absolute pressure measured from about 130 kPa to about 310 kPa in the controlled discharge tube. The filaments extruded from the extrusion nozzle have a moisture content of about 20% and / or about 25% to about 50% and / or about 55% by weight. The filaments are dried by a dry air stream having a temperature of about 149 ° C. to about 315 ° C. that is fed through a drying nozzle by an electrical resistance heating device and discharged at an angle approximately perpendicular to the general orientation of the filament being extruded. The The filaments are dried to about 45% moisture content to about 15% moisture content (ie, consistently about 55% to consistently about 85%) and collected, for example, in a collection device such as a mobile small hole belt Is done.

  The process parameters for producing the filaments of the present invention are shown in Table 4 below.

  A cross-linking system with a cross-linking agent such as imidazolidinone can cross-link the hydroxy polymer together with or without a curing step to provide a filament having wet strength. Crosslinking occurs so that the polymer melt composition can be fed through an extrusion nozzle to produce a filament. In other words, the crosslinking system does not crosslink the hydroxy polymer in the polymer melt composition at an early stage, so the extrusion nozzle is clogged and no filaments are produced.

  The filaments of the present invention do not contain coatings and / or other surface treatments in a pre-existing manner, such as coatings on fibers, films or foams. However, in one embodiment of the invention, the filaments according to the invention can be coated and / or surface treated with the crosslinking system of the invention.

  In one example, the filaments produced by the polymer processing operation are about 110 ° C. to about 215 ° C. and / or about 110 ° C. to about 200 ° C. and / or about 120 ° C. to about 195 ° C. and / or about 130 ° C. to about 130 ° C. Over a period of about 0.01 and / or 1 and / or 5 and / or 15 seconds to about 60 minutes and / or about 20 seconds to about 45 minutes and / or about 30 seconds to about 30 minutes at a curing temperature of 185 ° C. Can be cured. Alternative curing methods may include radiation techniques such as UV, electron beam, IR and other methods of increasing temperature.

  Furthermore, the filaments can be cured at room temperature for several days either after being cured at a temperature above room temperature or instead of being cured at a temperature above room temperature.

  The filaments of the present invention may contain melt-spun and / or spunbond filaments, hollow filaments, shaped filaments, such as bifilament filaments and composite filaments, especially bicomponent filaments. Composite filaments, particularly bicomponent filaments, can be in the form of side-by-side, sheath-core, chopped pie, ribbon, sea-island, or any combination thereof. The sheath may be continuous or discontinuous around the core. The weight ratio of sheath to core can be from about 5:95 to about 95: 5. The filaments of the present invention can have different geometric shapes including circular, oval, star, rectangular, and various other variations.

Non-limiting Examples of Fibrous Structures Example 1-Fibrous structures comprising starch filaments / wood pulp fibers Kuraray Co. 7.5% Mowol 10-98 (polyvinyl alcohol) commercially available from 19% Ethylex 2035 (ethoxylated starch) commercially available from Tate & Lyle, 19% CPI 050820 (thinned with acid) commercially available from Corn Products International -156, 0.5% sulfosuccinate surfactants such as Aerosol AOT, commercially available from Cytec Industries, Hychem, Inc. Polymer melt composition comprising 0.25% Hyperfloc NF221 (polyacrylamide), 3.25% imidazolidinone crosslinking agent (DHEU), and 0.5% ammonium chloride (crosslinking accelerator) available from Aldrich, commercially available from Prepare things. The molten composition is heated and extruded with a co-rotating twin screw extruder at about 50% solids (50% H ₂ O) as described above.

The polymer melt composition is then extruded into a series of meltblown spinnerets oriented at different angles with respect to the machine direction, providing a plurality of filaments from each spinneret. The diameter of the filament derived from each spinneret is reduced by a saturated air flow, the filament is collected on another filament, and a filament layer is formed to form a nonwoven fabric substrate. Two or more filaments of the filament layer exhibit different orientations relative to the machine direction. The formed nonwoven substrate exhibits a basis weight of from about 10 g / m < ² > to about 120 g / m < ² > as described herein above. The filaments are dried by convection drying and then deposited on the belt to form a nonwoven substrate. These meltblown filaments are essentially continuous filaments.

  When using two or more spinnerets to make a filament source, two or more spinnerets are adjacent together, then a seam filament forming nozzle opening in the first spinneret, and a second spinneret The spinneret assembly can also be made by adjoining the first spinneret to the second spinneret such that the maximum distance between the seam filament forming nozzle openings at is less than 9 mm and / or less than 7 mm and / or less than 5 mm. . In addition to adjoining the spinneret, an air plate is used in the spinneret assembly to cover the seam formed by the adjacent spinneret. The purpose of the air plate, which is the airflow, is to avoid that the filaments produced by the spinneret assembly collide with neighboring filaments, so that the filaments and / or discharge fibers from the spinneret assembly can cause rope formation. Because.

  Commercially available wood pulp fibers available as roll-milled pulp from Georgia Pacific, namely Southern Softwood Kraft (SKK), are crushed by a hammer mill and conveyed by a blower to a commercially available airlaid device from Dan-Web. Wood pulp fibers are deposited as a solid additive on the nonwoven substrate surface.

The additional polymer melt composition is extruded into a further meltblown spinneret oriented at an angle of about 90 ° to the machine direction to produce an additional filament layer (scrim). This additional filament layer is deposited on the wood pulp fibers to form a fibrous structure in which the wood pulp fibers are disposed between the nonwoven substrate and the scrim. The scrim typically exhibits a basis weight of from about 0.1 g / m ² to about 10 g / m ² .

  Next, the fibrous structure is joined and joined between the nonwoven substrate and the scrim so that the wood pulp fibers are placed between the nonwoven substrate and the scrim to form the final fibrous structure. Form a site. A joining process can be used to impart a pattern to the final fibrous structure and / or to emboss the final fibrous structure. During the fibrous structure manufacturing process, the fibrous structure can be humidified, for example, prior to joining and / or embossing.

  The final fibrous structure is then wound around the core in a convoluted manner to produce a sanitary tissue product.

  Fibrous structures, final fibrous structures, and / or sanitary tissue products incorporating final fibrous structures exhibit a tensile ratio of 2 or less.

Test Methods Unless otherwise specified, all tests described herein, including those described in the definition section, and the test methods described below, will be approximately 23 hours over at least 2 hours prior to testing. Perform on a sample conditioned in a room adjusted to a temperature of ± 1.0 ° C. and 50% ± 2% relative humidity. Samples to be tested are “usable units”. As used herein, “usable unit” means a sheet, flat material from roll stock, pre-converted flat material, and / or single-ply or multi-ply products. All tests are performed under the same environmental conditions and in such conditioned rooms. Samples with defects such as wrinkles, tears, and holes are not tested. Samples prepared as described herein are considered dry samples (eg, “dry filaments”) for testing purposes. All devices are inspected according to the manufacturer's instructions.

Basis Weight Test Method The basis weight of a fibrous structure in which 12 usable units are stacked is measured using a top chemical balance with a resolution of ± 0.001 g. The scale is protected from airflow and other obstructions using a draft shield. 8.9 cm ± 0.0089 cm x 8.9 cm ± 0.0089 cm (3.500 inches ± 0.0035 inches x 3.500 inches ± 0.0035 inches) prepare.

  Cut the sample into squares with a precision punching die. A laminated body having a thickness of 12 samples is formed by combining the cut out squares. Measure the mass of the sample stack and round off to the nearest 0.001 g and record the result.

The basis weight is lbs / 3000 ft ² or g / m ² and has the following formula:
Basis weight = (laminate mass) / [(area of one square sample in the laminate) × (number of laminated square samples)].

For example,
Basis weight (lbs / 3000 ft ² ) = [[laminate mass (g) /453.6 (g / lbs)] / [12.25 (in ² ) / 144 (in ² / ft ² ) × 12]] × 3000
Or basis weight (g / m ² ) = laminate mass (g) / [79.032 (cm ² ) / 10,000 (cm ² / m ² ) × 12]

Results are recorded rounded to the nearest 0.1 lbs / 3000 ft ² or 0.1 g / m ² . Using a precision stamping machine similar as described above, the sample area in the stack can be changed or changing the size of the sample so as to be at least 645.16cm 2 ⁽¹⁰⁰ square inches).

Dry Tensile Strength Test Method An extensible tensile tester with a computer interface using a load cell whose measured force is in the range of 10% to 90% of the load cell limit (the preferred device is the Thwing-Albert Instrument). Tensile strength is measured using Co (Wet Berlin, NJ), which is an EJB Vantage) at a constant speed. Smooth with suitable design for testing both movable (upper) and fixed (lower) pneumatic grippers on 2.54 cm (1 inch) wide sheet material (Thwing-Albert part number # 733GC) Attach to a stainless steel plated gripper. Supply air pressure of about 60 psi to the gripper.

  The eight usable units of the fibrous structure are divided into two laminates each consisting of four usable units. The usable units in each laminate are consistently oriented with respect to the machine direction (MD) and the cross machine direction (CD). One of the laminates is designated for MD testing and the other for CD testing. A 2.54 cm (1 inch) precision punching machine (Thwing-Albert JDC-1-10 or similar) is used, the CD laminate is used, and the strip laminate is 2.54 cm ± 0.025 cm (1.00 inch). ± 0.01 inch) width × 3-4 inch length (length of CD) is cut once. In the same way, the remaining laminate in the MD direction is cut (with the length dimension of the strip in the MD direction) to obtain a total of 8 samples, namely 4 CDs and 4 MD strips. Each strip to be tested is of usable unit thickness and is treated as a sample unit for testing.

  The tensile tester is programmed to raise the crosshead at a speed of 5.08 cm / min (2.00 inches / min) and pull while collecting force and extension data at a 20 Hz acquisition rate until the sample breaks. Conduct the test. The break sensitivity is set to 80%, i.e., when the measured force drops 20% of the maximum peak force, the test is terminated, after which the crosshead returns to its original position.

  The gauge length is set to 2.54 cm (1.00 inch). Zero crosshead and load cell. Insert the specimen into the open upper and lower jaws so that at least 1.3 cm (0.5 inch) of the specimen length is accommodated in each jaw. After aligning the specimens vertically in the upper and lower grips, tighten the upper grips. Make sure the specimens are aligned and tighten the lower grip. The specimen should be straight between the grips so that the load cell has a force of less than 5.0 g. Start the tensile tester and start data collection. The test is repeated in a similar manner for all 4 CD specimens and 4 MD specimens.

The software is programmed and calculated from the constructed force (g) vs. extension (inch) curve as follows:
Tensile strength is the maximum peak force (g) divided by the sample width (1 inch) and is rounded to the nearest 0.0038 N / cm (1 g / inch) and recorded as g / inch.

  Tensile strength (g / inch) is calculated for 4 CD unit samples and 4 MD unit samples. The average value of each parameter is calculated separately for CD and MD samples.

Calculation:
Tensile ratio = MD tensile strength (g / inch) / CD tensile strength (g / inch)

  The dimensions and values disclosed herein are not to be understood as being strictly limited to the exact numerical values recited. Rather, unless otherwise specified, each such dimension is intended to mean both the recited value and a functionally equivalent range surrounding that value. For example, a dimension disclosed as “40 mm” is intended to mean “about 40 mm”.

  All references cited herein, including any cross-references or related patents or related applications, are hereby incorporated by reference in their entirety, unless expressly excluded or otherwise limited. Citation of any document is not an admission that such document is prior art to all inventions disclosed or claimed in this application, and such document alone or in all other references. And no reference to, teaching, suggestion or disclosure of any such invention in any combination thereof. Further, in this document, the meaning assigned to a term in this document if the scope of any meaning or definition of the term contradicts any meaning or definition of a similar term in a document incorporated by reference. Or it shall conform to the definition.

  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. Accordingly, it is intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.

Claims (15)

  A fibrous structure comprising a plurality of filaments comprising one or more polysaccharides, wherein the fibrous structure exhibits a tensile ratio of 2 or less when measured according to the dry tensile strength test method described herein.   At least one of the one or more polysaccharides is starch, starch derivative, starch copolymer, chitosan, chitosan derivative, chitosan copolymer, cellulose, cellulose derivative, cellulose copolymer, hemicellulose, hemicellulose derivative, hemicellulose copolymer, and mixtures thereof Preferably, at least one of the one or more polysaccharides is selected from the group consisting of starch, starch derivatives, starch copolymers, and mixtures thereof, more preferably the at least one The fibrous structure of claim 1 wherein the polysaccharide comprises ethoxylated starch or starch diluted with acid.   The said at least one filament further comprises a hydroxy polymer selected from the group consisting of polyvinyl alcohol, polyvinyl alcohol derivatives, polyvinyl alcohol copolymers, gums, arabinans, galactans, proteins, and mixtures thereof. Fibrous structure.   The at least one filament is selected from the group consisting of polyacrylamide and derivatives thereof; polyacrylic acid, polymethacrylic acid, and esters thereof; polyethyleneimine; a copolymer made from a monomer mixture of the polymer; and mixtures thereof The fiber according to any one of claims 1 to 3, further comprising a polymer, preferably wherein the polymer exhibits a weight average molecular weight of greater than 500,000 g / mol, more preferably the polymer comprises polyacrylamide. Sex structure.   The fibrous structure according to any one of claims 1 to 4, wherein the at least one filament further comprises a surfactant, and preferably the surfactant further comprises a sulfosuccinate surfactant. The fibrous structure exhibits ^a basis weight of ^{10g / m 2 ~120g / m 2} , the fibrous structure according to any one of claims 1 to 5.   The fibrous structure according to any one of claims 1 to 6, wherein the fibrous structure further comprises one or more solid additives.   At least one of the one or more solid additives comprises fibers, preferably the fibers comprise pulp fibers, more preferably the pulp fibers comprise hardwood pulp fibers, softwood pulp fibers, and mixtures thereof. The fibrous structure according to any one of claims 1 to 7, wherein the fibrous fibers are selected from the group consisting of, and even more preferably, the pulp fibers comprise Eucalyptus pulp fibers or chemically treated pulp fibers.   The fibrous structure of claim 7, wherein one or more of the solid additives are present on the surface of the fibrous structure.   The fibrous structure further comprises a scrim coupled to the surface of the fibrous structure such that the solid additive is disposed between the scrim and the surface of the fibrous structure, more preferably The scrim material is bonded to the surface at one or more bonding sites of the fibrous structure, and even more preferably, the one or more bonding sites include thermal bonding or pressure bonding. Fibrous structure.   The fibrous structure of claim 10, wherein the scrim material is joined to the surface of the fibrous structure by a plurality of separate joining sites.   The fibrous structure according to any one of claims 1 to 11, wherein the fibrous structure is embossed. It said fibrous structure exhibits a density of less than 0.60 g / cm ^3, the fibrous structure according to any one of claims 1 to 12.   A monolayer or multilayer sanitary tissue product comprising the fibrous structure according to any one of claims 1-13. It is a manufacturing method of the fibrous structure according to any one of claims 1 to 14,
a. Supplying a plurality of filaments from a filament source; and b. Collecting the filament with a collection device and forming the fibrous structure such that the fibrous structure exhibits a tensile ratio of 2 or less when measured according to the tensile ratio test method described herein; Preferably, the method further comprises:
c. Supplying a plurality of solid additives from a solid additive source such that solid additives are recovered on the surface of the fibrous structure, more preferably, the method further comprises:
d. Providing a scrim of material; and e. Joining the scrim of the material to the surface of the fibrous structure such that the solid additive is disposed between the scrim material and the fibrous structure.

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