MX2014009018A

MX2014009018A - Fibrous structures and methods for making same.

Info

Publication number: MX2014009018A
Application number: MX2014009018A
Authority: MX
Inventors: David William Cabell; John Gerhard Michael; Hassan Eroglu
Original assignee: Procter & Gamble
Priority date: 2012-02-22
Filing date: 2013-02-21
Publication date: 2014-08-29
Also published as: EP2817454B1; EP2817454A1; WO2013126492A8; WO2013126492A1; JP2015511278A; CA2865269A1; RU2014128490A; CN104254647A; US20130216809A1; CA2865269C; BR112014020483A2; AU2013222507A1

Abstract

Fibrous structures containing a plurality of solid additives and a plurality of filaments are provided.

Description

FIBROUS STRUCTURES AND METHODS TO MANUFACTURE THEM FIELD OF THE INVENTION The present invention relates to fibrous structures, more particularly, to fibrous structures comprising a plurality of solid additives and a plurality of filaments, and, even more particularly, to fibrous structures comprising a plurality of solid additives and a plurality of filaments of starch, as well as methods to manufacture these fibrous structures.

BACKGROUND OF THE INVENTION Fibrous structures comprising solid additives, such as pulp fibers, and filaments, such as starch filaments, are known in the art. These fibrous structures have been manufactured by the use of filament sources, such as blow-melt matrices. Conventionally, blow-melt matrices have been oriented in the same manner with each other with respect to the machine direction of the fibrous structure that is manufactured with the filaments provided by those melt-blow matrices. For example, the melt blow molds have been oriented at an angle of 90 ° with respect to the machine direction. The problem of manufacturing fibrous structures with filament sources, such as melt-blow matrices, with an orientation, e.g. eg, 90 ° angle with respect to the machine direction, is that each layer of filaments within the fibrous structure provided by each filament source presents the same orientation between layers of filaments and sources of filaments, as illustrated in the Figure 1. Figure 1 shows a fibrous structure 10 comprising three layers 12 of filaments 14, wherein each layer 12 is produced by a filament source oriented at an angle of 90 ° with respect to the machine direction, which gives as a result, each layer 12 of filaments 14 has an orientation in the machine direction. As a result of the above, the fibrous structure 10, which contains solid additives 16 (eg, pulp fibers) and three layers 12 of filaments 14 having the same orientation, has a tensile ratio greater than 2, as measured by according to the dry tensile strength method described in the present invention. The impact of these layers of filaments having the same orientation can be accentuated because the fibrous structure is manufactured at speeds greater than 1.01 m / s (200 ft / min) and / or because the fibrous structure has a width greater than 50.8 cm (20 in.) In addition to the above, the manufacture of fibrous structures, without solid additives, is already known in the art. eg, without pulp fibers, from thermoplastic polymer filaments provided by spunbond matrices and / or blow-melt matrices oriented at different angles with respect to the machine direction of the fibrous structure.

Accordingly, there is a need to obtain a fibrous structure comprising a plurality of solid additives, e.g. g., pulp fibers, and a plurality of filaments, e.g. eg, filaments of starch, wherein the filaments are present in the fibrous structure in two or more different layers on the basis of their orientation in each layer, as well as methods for manufacturing those fibrous structures.

BRIEF DESCRIPTION OF THE INVENTION The present invention satisfies the need described above by providing novel fibrous structures comprising a plurality of solid additives, e.g. g., pulp fibers, and a plurality of filaments, e.g. eg, filaments of starch.

In an example of the present invention, there is provided a fibrous structure comprising a plurality of solid additives and a plurality of filaments, wherein the filaments are present in the fibrous structure in two or more different layers of filaments on the basis of their orientation in each layer.

In another example of the present invention, there is provided a fibrous structure comprising a plurality of filaments comprising one or more polysaccharides, wherein the fibrous structure has a tensile ratio of 2 or less, measured according to the method of resistance to the dry traction described in the present description.

In another example of the present invention, a single or multi-sheet paper health product comprising a fibrous structure according to the present invention is provided.

In yet another example of the present invention, a method for manufacturing a fibrous structure is provided; The method comprises the steps of: to. providing a plurality of filaments from a filament source; Y b. collecting the filaments in a collection device to form a fibrous structure, such that the fibrous structure has a tensile ratio of 2 or less, measured according to the Traction Ratio Test Method described in the present invention.

In still another example of the present invention, a method for manufacturing a fibrous structure is provided; The method comprises the steps of: to. providing first filaments from a first filament source; b. providing second filaments from a second filament source; c. optionally, providing additional filaments from additional filament sources; d. provide solid additives from a source of solid additives; Y and. collecting the first and second filaments (and any other additional filament) and the solid additives to form a fibrous structure, wherein the first filament source is oriented at a first angle with respect to the machine direction of the fibrous structure, and the second filament source is oriented at a second angle with respect to the machine direction, other than the first angle.

Accordingly, the present invention provides fibrous structures and methods for manufacturing fibrous structures that meet the needs described above.

BRIEF DESCRIPTION OF THE FIGURES Figure 1 is a schematic representation of a fibrous structure of the previous matter; Figure 2 is a schematic representation of an example of a fibrous structure in accordance with the present invention; Figure 3 is a photograph of a filament layer of a fibrous structure produced with a filament source oriented at an angle of 90 ° with respect to the machine direction of the fibrous structure; Figure 4 is a photograph of a filament layer of a fibrous structure produced with a filament source oriented at an angle of about 40 ° with respect to the machine direction of the fibrous structure; Figure 5 is a schematic representation of an example of fibrous structure according to the present invention; Figure 6 is a cross-sectional view of the fibrous structure of Figure 5 taken along line 6-6; Figure 7 is a schematic representation of an example of a method for making a fibrous structure in accordance with the present invention; Figure 8 is a schematic representation of an example of a process portion for manufacturing a fibrous structure in accordance with the present invention; Figure 9 is a schematic representation of an example blow-melt matrix according to the present invention.

Figure 10A is a schematic representation of a barrel example of a twin screw extruder according to the present invention; Y Figure 10B is a schematic representation of a screw configuration and mixing element for the twin screw extruder of Figure 10A.

DETAILED DESCRIPTION OF THE INVENTION Definitions As used in the present description, "fibrous structure" means a structure comprising one or more filaments, e.g. eg, a plurality of filaments, and one or more solid additives, such as, a plurality of pulp fibers. In one example, a fibrous structure according to the present invention is an association of solid filaments and additives that together form a structure capable of performing a function.

Non-limiting examples of processes for manufacturing fibrous structures according to the present invention include the known wet, solution and dry filament spinning processes typically referred to as non-woven fabrics processes. In one example, the filament spinning process is a melt blown process, wherein the filaments are provided from a meltblown matrix (a source of filaments). Further processing of the fibrous structure can be performed in such a way that a fibrous structure is formed. For example, the finished fibrous structure is a fibrous structure that is wound onto a coil at the end of a fibrous structure manufacturing process. The finished fibrous structure can subsequently be converted into a finished product, for example, a sanitary product of raster paper.

As used in the present invention, "filament" means an elongated particle having a length that greatly exceeds its average diameter, that is, an average length-to-diameter ratio of at least about 10. In one example, the filament in a single filament for a thread, which is a strand of filaments braided together by their length. In one example, a filament exhibits a length equal to or greater than 5.08 cm and / or equal to or greater than 7.62 cm and / or equal to or greater than 10.16 cm and / or equal to or greater than 15.24 cm.

Typically, the filaments are considered continuous or substantially continuous, especially with respect to the fibrous structure in which they are present. The filaments are relatively longer than the fibers. Non-limiting examples of filaments include filaments blown and / or spunbond. Non-limiting examples of polymers that can be spun into filaments include natural polymers such as starch, starch derivatives, cellulose such as rayon and / or lyocell; and derivatives of cellulose, hemicellulose, hemicellulose derivatives and synthetic polymers including, but not limited to, thermoplastic polymer filaments such as polyesters, nylons, polyolefins such as polypropylene filaments, polyethylene filaments and biodegradable thermoplastic fibers such as filaments of polylactic acid, polyhydroxyalkanoate filaments, polyesteramide filaments and polycaprolactone filaments.

The filaments of the present invention can be single component and / or multi component. For example, the filaments may comprise bicomponent filaments. The bicomponent filaments can have any configuration, such as side by side, sheath and core, islets and the like.

As used in the present description, "solid additive" means a solid particulate, such as a powder, granule and / or fiber.

As used in the present description, "fiber" refers to an elongate particulate, as described above, exhibiting a length of less than 5.08 cm and / or less than 3.81 cm and / or less than 2.54 cm.

Typically, the fibers are considered discontinuous, especially with respect to the fibrous structure in which they are present. Non-limiting examples of fibers include pulp fibers such as wood pulp fibers and shortened fibers synthetics such as polypropylene, polyethylene, polyester, copolymers thereof, rayon, glass fibers and polyvinyl alcohol fibers.

The staple fibers can be produced by spinning filament tow and then cutting the tow into segments smaller than 5.08 cm and producing discontinuous fibers.

In an example of the present invention, a fiber can be a fiber of natural origin, which means that it is obtained from a source of natural origin, such as a vegetable source, for example, a tree and / or a plant. Said fibers are typically used in papermaking and are often referred to as papermaking fibers. Papermaking fibers useful in the present invention include cellulosic fibers, known as wood pulp fibers. Some wood pulps useful in the present invention are chemical pulps, for example, Kraft, sulphite and sulfate pulps, as well as mechanical pulps including, for example, crushed wood, thermomechanical pulps and chemically modified thermomechanical pulps. However, chemical pulps may be preferred as they impart a superior tactile feel of softness to the sheets of fabric fabricated therefrom. Pulps derived from deciduous trees (hereinafter referred to as "hardwood") and conifers (hereinafter referred to as "softwood") can be used. The hardwood and softwood fibers can be blended or alternatively deposited in layers to provide a stratified web. In addition, fibers derived from recycled paper, which may contain any or all of the fiber categories mentioned above, as well as other non-fibrous polymers, such as fillers, softening agents, wet strength agents, are applicable in the present invention. dry, and adhesives used to facilitate the production of original paper.

Additionally, of the various wood pulp fibers, other cellulosic fibers such as cotton, rayon, lyocell, and bagasse fibers may be used in the fibrous structures of the present invention.

In another example, the fibrous structure may comprise solid additives comprising trichomes and / or hair of the seeds.

As used in the present description, "filament layer" means a plurality of filaments that form at least part of a fibrous structure, wherein the filaments of the layer extend along a common primary direction. In other words, the filaments of the layer have orientation in the common primary direction. For example, the filaments of a layer may have an orientation in the machine direction. In another example, the filaments of one layer may have a different orientation of the machine direction, e.g. eg, an orientation along an angle between the machine direction and the direction transverse to the machine. In one example, one or more layers of filaments may be combined, such as deposited on one another, to form a fibrous structure in accordance with the present invention. Additionally, the fibrous structure may comprise two or more different filament layers. For example, as illustrated in Figure 2, a fibrous structure 10 may comprise a first layer 18 of filaments 14 having an orientation in the machine direction and a second layer 20 of filaments 14 having a different orientation from the orientation in the direction of machine presented by the first layer 18.

As used in the present description, "orientation" with respect to the orientation of the filaments within a filament layer means that the filaments within a layer extend along a common primary direction. Obviously, there are some filaments that extend in a secondary direction within a layer, but the vast majority of the filaments in a layer extend in a primary direction common, and that common primary direction establishes the orientation of the filaments within a layer. As illustrated in Figure 3, a filament layer has an orientation in the machine direction. In Figure 4, a filament layer has an angular orientation with respect to the machine direction of the layer. In another example, the angle of a filament source (with respect to the machine direction of a fibrous structure being manufactured), such as a meltblown matrix, provides the filaments of the filament layer produced from the Source of filaments with a defined orientation. Therefore, if two or more filament layers are produced from two or more filament sources (eg, melt blow matrices) oriented at different angles (eg, within the range of 0 to 90 ° positive or negative from the MD) with respect to the machine direction, the filaments within the two or more layers will present different predetermined orientations.

In order to measure the angle of orientation of a filament source, such as a melt blow mold, the smallest angle is measured with respect to the machine direction and is considered as the orientation angle of the filament source. . If the orientation angles of a filament source are equal with respect to the machine direction, the orientation angle is 90 °.

As used in the present description, "non-woven fabric substrate" means a weft comprising one or more layers of filaments of the present invention.

As used in the present description, "sanitary paper product" means a fibrous structure useful as an implement for cleaning after urination and defecation (toilet paper), for otorhinolaryngological discharges (disposable handkerchiefs), and for multifunctional absorbent uses. and cleaning (absorbent towels). The toilet paper product can be rolled several times on itself, around of a core or without a core, to form a roll of toilet paper product.

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

The sanitary paper products of the present invention may have a basis weight of between about 10 g / m2 to about 120 g / m2 and / or from about 15 g / m2 to about 1 10 g / m2 and / or about 20 g / m2 to approximately 100 g / m2 and / or from approximately 30 to 90 g / m2. Additionally, the paper sanitary product of the present invention may have a basis weight of between about 40 g / m2 to about 120 g / m2 and / or from about 50 g / m2 to about 1 10 g / m2 and / or about 55 g / m2 to approximately 105 g / m2 and / or from approximately 60 to 100 g / m2.

The tissue paper health products of the present invention may have a density of less than about 0.60 g / cm3 and / or less than about 0.30 g / cm3 and / or less than about 0.20 g / cm3 and / or less than about 0.10 g / cm3. cm3 and / or less than about 0.07 g / cm3 and / or less than about 0.05 g / cm3 and / or from about 0.01 g / cm3 to about 0.20 g / cm3 and / or from about 0.02 g / cm3 to about 0.10 g / cm3. cm3.

The sanitary paper products of the present invention can be presented in the form of rolls of sanitary paper product. The rolls of sanitary paper product may comprise a plurality of connected, but perforated sheets of fibrous structure, which may be dispensed separately from the adjacent sheets.

The sanitary paper products of the present invention can comprising additives such as softening agents, temporary wet strength agents, permanent wet strength agents, bulk softening agents, lotions, silicones, wetting agents, latexes, patterned latexes and other types of additives suitable for inclusion in and / or or about sanitary paper products.

As used herein, "lightweight" means a weft material, such as a web comprising filaments, which is used to superimpose solid additives within the fibrous structures of the present invention, such that the solid additives they are located between the weft material and another layer of filaments within the fibrous structures In one example, the light weave comprises a weft material having a basis weight less than 10 g / m2 and / or less than 7 g / m2 and / or less than 5 g / m2 and / or less than 3 g / m2, and the remaining (s) layer (s) of filaments of the fibrous structure of the present invention have (n) a further basis weight of 10 g / m2 and / or greater than 15 g / m2 and / or greater than 20 g / m2 and / or approximately 120 g / m2.

As used herein, "hydroxyl polymer" includes any hydroxyl-containing polymer from which the filaments of the present invention can be manufactured. In one example, the hydroxyl polymer of the present invention includes more than 10%, and / or more than 20%, and / or more than 25% hydroxyl entities by weight. In another example, the hydroxyl that is inside the hydroxyl-containing polymer does not form part of a larger functional group such as a carboxylic acid group.

As used in the present description, "non-thermoplastic" means, with respect to a filament in its entirety and / or a polymer within a filament, that the filament and / or the polymer does not exhibit a melting point and / or a dot. of softening that allows it to flow under pressure in the absence of a plasticizer, such as water, glycerin, sorbitol, urea and the like.

As used in the present description, 'thermoplastic' means, with respect to a filament as a whole and / or a polymer within a filament, that the filament and / or polymer exhibits a melting point and / or softening point a certain temperature that allows it to flow under pressure.

"That does not contain cellulose", as used in the present description, means that an amount of less than 5% and / or less than 3% and / or less than 1% and / or less than 0.1% and / or is present. 0% by weight of cellulosic polymer, polymer derived from cellulose and / or cellulose copolymer in the fibrous element. In an example, "not containing cellulose" means that an amount of less than 5% and / or less than 3% and / or less than 1% and / or less than 0.1% and / or 0% by weight is present. , of cellulosic polymer in the fibrous element.

As used in the present description with respect to filaments, "associated", "association" and / or "associating" means to combine filaments, in direct contact or in indirect contact, so as to form a fibrous structure. In one example, the associated filaments could be joined, for example, by adhesives and / or thermal bonds. In another example, the filaments could associate with each other by depositing in the same fibrous structure manufacturing web.

"Weight average molecular weight", as used in the present description, means the weight average molecular weight as determined by means of gel permeation chromatography according to the protocol found in the publication Colloids and Surfaces A. Physico Chemical & Engineering Aspects, Vol. 162, 2000, p. 107-121.

As used in the present description, "basis weight" is the weight per unit area indicated in g / m2.

As used in the present description, "machine address" or "MD" (for its acronym in English) refers to the direction parallel to the flow of the fibrous structure through a machine to manufacture fibrous structures, such as a paper machine and / or equipment for the manufacture of fibrous structure products.

As used in the present description, "machine transverse direction" or "CD" refers to the direction perpendicular to the machine direction in the same plane of the fibrous structure or tissue paper hygienic product comprising the fibrous structure .

"Sheet" or "sheets", as used in the present description, means an individual fibrous structure optionally to be placed in a face-to-face relationship substantially contiguous with other sheets, forming a fibrous structure of multiple sheets. In addition, it is contemplated that a single fibrous structure can effectively form two "sheets" or multiple "sheets", for example, when folded on itself.

As used herein, "nozzle head" means a plate comprising one or more filament-forming nozzles from which filaments of a molten composition may flow. In one example, the nozzle head comprises a plurality of filament forming nozzles arranged in one or more rows and / or columns. This nozzle head is known as a multi-row nozzle head.

As used in the present description, "adjacent to each other", in relation to two or more adjoining nozzle heads, means that one surface of a nozzle head is in contact with a surface of another nozzle head.

As used in the present description, "stitching" means the line of contact between two adjoining nozzle heads.

As used in the present description, "seam opening of the filament forming nozzle" means one or more apertures of filament forming nozzles closer to the seam formed by two adjacent nozzle heads.

As used in the present description, the articles "a" and "ones" when used in the present description, for example "an anionic surfactant" or "a fiber" are understood to mean one or more of the material claimed or describes All percentages and proportions are calculated by weight, unless indicated otherwise. All percentages and proportions are calculated based on the total composition unless otherwise indicated.

Unless otherwise specified, all levels of the component or composition are expressed in reference to the active level of that component or composition, and are exclusive of impurities, for example, residual solvents or by-products, which may be present. in commercially available sources.

Filaments In one example, the fibrous structure of the present invention comprises filaments comprising a hydroxyl polymer. In another example, the fibrous structure could comprise starch and / or filaments derived from starch. The starch filaments may further comprise polyvinyl alcohol and / or other polymers.

The filaments of the present invention can be produced from a polymeric melt composition comprising a hydroxyl polymer, such as an uncrosslinked starch, a crosslinking system comprising a crosslinking agent, such as an imidazolidinone, and water. The polymeric melt composition may further comprise a surfactant, such as a sulfosuccinate surfactant. A non-limiting example of a suitable sulfosuccinate surfactant includes Aerosol® AOT (a sodium dioctyl sulfosuccinate) and / or Aerosol® MA-80 (a sodium dihexylsulfosuccinate), which is commercially available from Cytec Industries, Woodland Park, NJ.

In one example, 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 about 90% and / or about 80% by weight of the hydroxyl polymer filament, such as starch, which can be crosslinked. In one example, the filament comprises an ethoxylated starch and a starch diluted with acid, which may be crosslinked.

Additionally, of the hydroxyl polymer, the filament may comprise polyvinyl alcohol at a level of 0% and / or 0.5% and / or 1% and / or from 3% to about 15% and / or to about 12% and / or about 10% and / or about 7% by weight of the filament.

The filaments may comprise a surfactant, such as a sulfosuccinate surfactant, at a level of 0% and / or of about 0.1% and / or from about 0.3% to about 2% and / or about 1.5% and / or about 1.1% and / or about 0.7% by weight of the filament.

The filaments may further comprise a polymer selected from the group consisting of: polyacrylamine and its derivatives; polyacrylic acid, polymethacrylic acid and its esters; polyethyleneimine; copolymers made from mixtures of monomers of the aforementioned polymers; and mixtures thereof at a level of 0% and / or about 0.01% and / or about 0.05% and / or about 0.5% and / or about 0.3% and / or about 0.2% by weight of the filament.

These polymers can have an average molecular weight greater than 500,000 g / mol. In one example, the filament comprises polyacrylamine.

The filaments may further comprise a crosslinking agent, such as an imidazolidinone, which may be crosslinked (crosslinking of the hydroxyl polymer present in the filaments) at a level of about 0.5% and / or about 1% and / 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% by weight of the filament. In addition to the crosslinking agent, the filament may comprise a crosslinking facilitator as auxiliary to the crosslinking agent at a level of 0% and / or of approximately 0.3% and / or approximately 0.5% and / or approximately 2% and / or about 1.7% and / or about 1.5% by weight of the filament.

The filament may further comprise several additional ingredients, such as propylene glycol, sorbitol, glycerin and mixtures thereof.

Polymers The filaments of the present invention that associate to form the fibrous structures of the present invention could contain different types of polymers, such as hydroxyl polymers, non-thermoplastic polymers, thermoplastic polymers and mixtures thereof.

Non-limiting examples of hydroxyl polymers in accordance with the present invention include polyols, such as polyvinyl alcohol, polyvinyl alcohol derivatives, polyvinyl alcohol copolymers, starch, starch derivatives, starch copolymers, chitosan, chitosan derivatives, copolymers of chitosan, cellulose, cellulose derivatives, such as cellulose ester and ester derivatives, cellulose copolymers, hemicellulose, hemicellulose derivatives, hemicellulose copolymers, gums, arabinans, galactans, proteins and other polysaccharides, and mixtures thereof.

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

In another example, a hydroxyl polymer of the present invention is a non-thermoplastic polymer.

The hydroxyl polymer could have a weight average molecular weight of from about 10,000 g / mol to about 40,000,000 g / mol and / or greater than about 100,000 g / mol and / or greater than about 1,000,000 g / mol and / or greater than about 3,000,000 g / mol and / or greater than about 3,000,000 g / mol to about 40,000,000 g / mol. The hydroxyl polymers with higher and lower molecular weight could be used in combination with hydroxyl polymers having a certain desired weight average molecular weight.

Some well-known modifications of hydroxyl polymers, for example, natural starches, include chemical modifications or enzymatic modifications. For example, the natural starch can be diluted with acid, hydroxyethylated, hydroxypropylated or oxidized. Additionally, the hydroxyl polymer may comprise a hydroxyl polymer of corn starch.

The polyvinyl alcohols of the present invention can be grafted with other monomers to modify their properties. A wide variety of monomers has been successfully grafted into polyvinyl alcohols. Non-limiting examples of these 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 acrylate esters . Polyvinyl alcohols comprise the various products of hydrolysis formed from polyvinyl acetate. In one example, the hydrolysis level of the polyvinyl alcohols is greater than 70% and / or greater than 88% and / or greater than 95% and / or approximately 99%.

As used in the present description, "polysaccharides" refers to natural polysaccharides and derivatives of modified polysaccharides and / or polysaccharides. Some suitable examples of polysaccharides include, but are not limited to, starches, starch derivatives, chitosan, chitosan derivatives, cellulose, cellulose derivatives, hemicellulose, hemicellulose derivatives, gums, arabinans, galactans and mixtures thereof. The polysaccharides could exhibit a weight average molecular weight of from about 10,000 to about 40,000,000 g / mol and / or greater than about 100,000 and / or greater than about 1,000,000 and / or greater than about 3,000,000 and / or greater than about 3,000,000 to approximately 40,000,000.

Non-cellulosic hydroxyl polymers and / or non-cellulosic derivatives and / or non-cellulosic copolymers, such as non-cellulosic polysaccharides, may be selected from the group consisting of: starches, starch derivatives, chitosan, chitosan derivatives, hemicellulose, derivatives of hemicellulose, gums, arabinans, galactanas and mixtures thereof.

In one example, the filaments of the present invention do not have water insoluble thermoplastic polymers.

Solid additives The solid additives of the present invention can be applied to a surface of a filament layer in a solid form. In other words, the solid additives of the present invention can be distributed directly on a surface of a layer of filaments without being in liquid phase, that is, without the solid additive melting and without suspending the solid additive in a liquid carrier or carrier. Thus, the solid additive of the present invention does not require a liquid phase or a liquid carrier or carrier for the purpose of being distributed on a surface of a filament layer. The solid additive of the present invention can be distributed by a gas or gas combinations. In one example, in simple terms, a solid additive is an additive that does not take the shape of the container when placed inside it.

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

The solid additives of the present invention may have different geometries or cross-sectional areas including round, elliptical, star-shaped, rectangular, three-lobed and other eccentric eccentricities.

In one example, the solid additive may show a particle size of less than 6 mm or less than 5.5 mm or less than 5 mm or less than 4.5 mm or less than 4 mm or less than 2 mm in its maximum dimension.

The solid additive of the present invention may have 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 less than 5/1 to about 1/1. . A particle is not a fiber as defined in the present invention.

The solid additives could be present in the fibrous structures of the present invention at a level greater than about 1 and / or greater than about 2 and / or greater than about 4 and / or about 20 and / or about 15 and / or about 10. g / m2. In one example, a fibrous structure of the present invention comprises from about 2 to about 10 and / or from about 5 to about 10 g / m2 of solid additives.

In one example, solid additives are present in the fibrous structures of the present invention at a level greater than 5% and / or greater than 10% and / or greater than 20% at about 50% and / or at about 40% and / oa approximately 30% by weight.

In one example, solid additives 14 comprise fibers, for example, wood pulp fibers. The wood pulp fibers could be softwood pulp fibers and / or hardwood pulp fibers. In one example, the wood pulp fibers comprise eucalyptus pulp fibers. In another example, the wood pulp fibers comprise South coniferous kraft pulp (SSK) fibers.

The solid additives can be chemically treated, e.g. eg, chemically treated pulp fiber. In one example, the solid additives comprise softening agents and / or have the surfaces treated with softening agents. Non-limiting examples of suitable softening agents include silicones and / or quaternary ammonium compounds, such as PROSOFT® available from Hercules Incorporated. In one example, the solid additives comprise wood pulp treated with a quaternary ammonium compound softening agent, for example, available from Georgia-Pacific Corporation. An advantage of applying a softening agent only to the solid additives versus applying it to the entire fibrous structure and / or the non-woven substrate and / or the bonding material, ensures that the softening agent softens those components of the whole of the fibrous structure that need to be smoothed compared to the other components of the entire fibrous structure.

Nonwoven substrate The nonwoven fabric substrate of the present invention comprises one or more layers of filaments. Two or more layers of filaments that make up the nonwoven fabric substrate can have the same or different orientations. In one example, the nonwoven fabric substrate comprises two or more layers of filaments having different orientations.

In one example, the non-woven fabric substrate comprises a plurality of filaments comprising a hydroxyl polymer. The hydroxyl polymer could be selected from the group consisting of polysaccharides, derivatives thereof, polyvinyl alcohol, derivatives thereof, and mixtures thereof. In one example, the hydroxyl polymer comprises a starch and / or a starch derivative. The nonwoven substrate 12 could exhibit a basis weight greater than about 10 g / m2 and / or greater than about 14 g / m2 and / or greater than about 20 g / m2 and / or greater than about 25 g / m2 and / or greater than about 30 g / m2 and / or greater than about 35 g / m2 and / or greater than about 40 g / m2 and / or less than about 100 g / m2 and / or less than about 90 g / m2 and / or less than about 80 g / m2.

Fibrous structures As illustrated in Figures 5 and 6, in one example, the fibrous structure 10 of the present invention comprises a nonwoven fabric substrate 26 comprising one or more layers of filaments, a plurality of solid additives 16, such as pulp, which are located between the non-woven fabric substrate 26 and a lightweight fabric 28, which is bonded to the non-woven fabric substrate 26 at one or more attachment locations 30. The attachment site 30 is where at least a portion of the Lightweight fabric 28 and a portion of the non-woven fabric substrate 26 are connected to each other, such as through a thermal bond or a bond created by applying the lightweight fabric 28 and the non-woven fabric substrate 26 at high pressure. so as to produce a glaze effect ("pressure bonding").

In one example, the solid additives 16 could be evenly distributed on a surface 32 of the non-woven substrate 26.

In one example, lightweight fabric 28 comprises one or more layers of filaments of the present invention. In one example, lightweight fabric 28 consists of a single layer of filaments of the present invention. Lightweight fabric 28 and nonwoven fabric substrate 26 may comprise filaments having the same composition, e.g. eg, filaments containing hydroxyl polymer, such as starch filaments. The lightweight fabric 28 could be found in the fibrous structure of the present invention at a basis weight greater than 0.1 and / or greater than 0.3 and / or greater than 0.5 and / or greater than 1 and / or greater than 2 g / m2 and / or less than 10 and / or less than 7 and / or less than 5 and / or less than 4 g / m2. In one example, lightweight fabric 28 may be present in the fibrous structure of the present invention with a basis weight of from about 0.1 to about 4 g / m2.

One objective of the lightweight fabric 28 is to reduce the lint produced by the fibrous structure 10 by preventing the solid additives 16 from disassociating from the fibrous structure 10. The lightweight fabric 28 could also provide additional strength properties to the fibrous structure 10.

As shown in Figures 5 and 6, the binding sites 30 could comprise a plurality of different binding sites. The different binding sites may be present in the form of a repeated, non-random pattern. One or more attachment sites 30 could comprise a thermal bond and / or a pressure joint.

In one example, the fibrous structure of the present invention comprises a plurality of filaments, such as filaments containing hydroxyl polymer, wherein the filaments are present in the fibrous structure in two or more different layers of filaments on the basis of their orientation in each layer.

The fibrous structures of the present invention, unexpectedly, exhibit a tensile ratio (MD tensile / tensile on CD) less than 2 or less and / or less than 1.7 and / or less than 1.5 and / or less than 1.3 and / or less. 1.1 and / or greater than 0.7 and / or greater than 0.9, measured in accordance with the dry tensile strength method described in the present disclosure. In one example, the fibrous structures of the present invention have an average tensile ratio of about 0.9 to about 1.1, measured according to the dry tensile strength method described in the present disclosure.

Table 1 below shows examples of tensile ratios for fibrous structures of the present invention and comparative fibrous structures.

Table 1 The fibrous structure of the present invention could comprise a surface softening agent. The surface softening agent could be applied to a surface of the fibrous structure. The softening agent could comprise a silicone and / or a quaternary ammonium compound.

The fibrous structure of the present invention can comprise engravings, in such a way that the fibrous structure is engraved.

In one example, the fibrous structure comprises a nonwoven fabric substrate having a plurality of solid additives on both opposite surfaces of the nonwoven fabric substrate located between the surfaces of the nonwoven fabric substrate and one or more lightweight fabrics that are bonded together. to each surface of the non-woven fabric substrate. The solid additives may be different or the same, be present in the same or different levels and be uniformly distributed on the opposite surfaces of the non-woven fabric substrate. The lightweight fabric may be different or the same, be present in equal or different levels and be bonded to the opposite surfaces of the non-woven fabric substrate in one or more attachment sites.

In another example, the fibrous structure of the present invention may comprise a sheet within the multi-sheet sanitary paper product.

In another example, a sanitary paper product is provided comprising two or more sheets of the fibrous structure in accordance with the present invention. In one example, two or more sheets of the fibrous structure according to the present invention combine to form a multi-sheet sanitary paper product. The two or more sheets may be combined so that the solid additives are adjacent to at least one outer surface and / or each of the outer surfaces of a multi-sheet sanitary paper product.

Methods for making fibrous structures Figures 7 and 8 illustrate an example of a method for making a fibrous structure of the present invention. As illustrated in Figures 7 and 8, method 34 comprises the steps of: to. providing first filaments 36 from a first source 38 of filaments, which form a first layer 40 of filaments; b. providing second filaments 42 from a second source 44 of filaments, which form a second layer 46 of filaments; c. providing third filaments 48 from a third source 50 of filaments, which form a third layer 52 of filaments; d. providing solid additives 16 from a source 54 of solid additives; and. providing filament quarters 56 from a fourth source 58 of filaments, which form a fourth layer 60 of filaments; and f. collecting the first, second, third and fourth filaments 36, 42, 48, 56 and the solid additives 16 to form a fibrous structure 10, wherein the first filament source 38 is oriented at a first angle a with respect to the direction of fibrous structure machine 10; the second filament source 44 is oriented at a second angle β with respect to a machine direction different from the first angle a; the third source 50 is oriented at a third angle d with respect to a machine direction different from the first angle a and the second angle β, and where the fourth source 58 is oriented at a fourth angle e with respect to a different machine direction of the second angle ß and the third angle d.

The first, second and third layer 40, 46, 52 of filaments are collected in a collection device 62, which may be a band or fabric. The collection device 62 may be a patterned web that imparts a pattern, such as a repeated, non-random pattern to the fibrous structure 10 during the manufacturing process of the fibrous structure. The first, second and third layer 40, 46, 52 of filaments are collected (eg, one on top of the other) in the collection device 62 to form a multi-layer nonwoven fabric substrate 26 on which the layers are deposited. solid additives 16. The fourth filament layer 60 can then deposit on the solid additives 16 to form a lightweight fabric 28.

The first angle a and the fourth angle e may have the same angle, p. eg, 90 ° with respect to the machine direction.

The second angle ß and the third angle d can be the same angle, positive or negative one with respect to the other. For example, the second angle ß can be -40 ° with respect to the machine direction, and the third angle d can be + 40 ° with respect to the machine direction.

In one example, at least one of the first, second and third angles a, β, d is less than 90 ° with respect to the machine direction. In another example, the first angle a and / or the fourth angle e are approximately 90 ° with respect to the machine direction. In yet another example, the second angle ß and / or the third angle d is from about ± 10 ° to about ± 80 ° and / or from about ± 30 ° to about ± 60 ° with respect 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 can be formed on a non-woven fabric substrate 28 before being used in the process for manufacturing a fibrous structure described above. In this case, the non-woven fabric substrate 28 is likely to be in a matrix roll that can be unwound in the manufacturing process of the fibrous structure, and the solid additive 16 could be deposited directly onto a surface 32 of the non-woven fabric substrate 28.

In one example, the step of providing a plurality of solid additives 16 on the nonwoven fabric substrate 26 may comprise air laying of the solid additives 16 by means of an air laying former. A non-limiting example of a suitable air-laying former is available from Dan-Web of Aarhus, Denmark.

In one example, the step of providing fourth filaments 56, so that the filaments come into contact with the solid additives 16, comprises the step of depositing fourth filaments 56 so that at least one portion (in one example, all or substantially all the all) of the solid additives 16 come into contact with the fourth filaments 56, and thus the solid additives are located between the fourth layer 60 of filaments and the nonwoven fabric substrate 26. Once the fourth layer 60 of filaments is instead, the fibrous structure 10 may be subjected to a joining step that attaches the fourth filament layer 60 (in this case, the gauze 28) to the nonwoven fabric substrate 26. This joining step may comprise a bonding operation. thermal The thermal bonding operation may comprise passing the fibrous structure 10 through a grip point formed by the thermal bonding rolls 64, 66. At least one of the thermal bonding rolls 64, 66 may comprise a pattern which results in binding sites 30 formed in the fibrous structure 10.

In addition to a joining operation, the fibrous structure can be subjected to other post-processing operations, such as engraving, forming of tufts, passing through gear rolls, which includes passing the fibrous structure through a grip point formed between two coupled gear rolls, operations for imparting moisture, generation of ends with free fibers and surface treatment to form a fibrous structure finished In one example, the fibrous structure is passed by gear rollers, which consists in passing the fibrous structure through a gripping point formed by at least one pair of gear rollers. In one example, the fibrous structure is passed through gear rollers, so as to create ends with free fibers in the fibrous structure. The gear rollers may be passed before or after two or more fibrous structures are combined to form a multi-sheet sanitary paper product. If they are passed afterwards, the multi-sheet toilet paper product is passed through a nip formed by at least one pair of gear rollers.

The method for making a fibrous structure of the present invention may consist of coupling in closed form (wherein the fibrous structure is screwed twisted in a roll prior to a conversion operation) or directly coupling (where the fibrous structure is not twists in a twisted form on a roll before a conversion operation) with a conversion operation to engrave, print, deform, surface treat, or other post-training operation known to those skilled in the art. For the purposes of the present invention, the direct coupling means that the fibrous structure can proceed directly to a conversion operation instead of, for example, intricately wound onto a roll and then unscrewed to proceed to a conversion operation.

In one example, one or more sheets of the fibrous structure according to the present invention can be combined with another sheet of the fibrous structure, which, furthermore, can be a fibrous structure according to the present invention, to form a multi-sheet sanitary paper product having a tensile ratio of 2 or less and / or less than 1.7 and / or less than 1.5 and / or less than 1.3 and / or less than 1.1 and / or greater than 0.7 and / or greater than 0.9, measured according to the dry tensile strength method described in the present description. In one example, the multi-sheet sanitary paper product may be formed by combining two or more sheets of the fibrous structure in accordance with the present invention. In another example, two or more sheets of the fibrous structure according to the present invention can be combined to form a multi-sheet sanitary paper product, such that the solid additives present in the sheets of fibrous structure are adjacent to the surfaces. exteriors of the multi-sheet sanitary paper product.

The process of the present invention may include the preparation of individual rolls of fibrous structure and / or paper health products that comprise fibrous structures that are suitable for consumer use.

In one example, the filament sources comprise meltblown matrices that produce filaments from a polymeric melt composition according to the present invention. In one example, as illustrated in Figure 9, the blow-melt matrix 68 may comprise at least one filament-forming orifice 70, and / or 2 or more and / or 3 or more rows of filament-forming orifices 70 a from which the filaments are spun. At least one row of the filament-forming orifices 70 contains 2 or more and / or 3 or more and / or 10 or more filament-forming orifices 70. In addition to the filament-forming orifices 70, the melt-blow matrix 68 comprises fluid-releasing orifices 72, such as gas-releasing orifices, in one example, air-releasing orifices, which attenuate filaments that are formed from filament-forming orifices 70. One or more fluid-releasing orifices may be associated 72 with a filament forming orifice 70, so that the fluid exiting the fluid-releasing orifice 72 is parallel or substantially parallel (instead of angled as in a sharp edge matrix) to an outer surface of a filament exiting the filament-forming orifice 70. In one example, the fluid exiting the releasing orifice of fluid 72 is brought into contact with the outer surface of a filament formed from a filament-forming hole 70 at an angle less than 30 ° and / or less than 20 ° and / or less than 10 ° and / or less than 5th and / or approximately 0o. One or more fluid-releasing orifices 72 may be disposed about a filament-forming orifice 70. In one example, one or more fluid-releasing orifices 72 are associated with a single filament-forming orifice 70., such that the fluid exiting from those one or more fluid-releasing orifices 72 is brought into contact with the outer surface of a single filament that is formed from the single filament-forming orifice 70. In one example, the orifice fluid releaser 72 allows a fluid, such as a gas, e.g., air, to contact the outer surface of a filament formed from a filament forming hole 70, instead of coming into contact with an inner surface of a filament, like what happens when a hollow filament is formed.

Synthesis of the polymer melting composition The polymeric melt composition of the present invention can be prepared by the use of a screw extruder such as a twin screw extruder with slotted cylinder.

A barrel 74 of a Baker APV twin screw extruder (Peterborough, England) of 40: 1, 48 mm is schematically illustrated in Figure 10A. Barrel 74 is separated into eight zones identified as zones 1-8. The barrel 74 contains the extrusion screw and the mixing elements illustrated schematically in Figure 10B, and acts as a containment vessel during the extrusion process. In zone 1 there is a solids feed port 76 and also a liquid feed port 78.

In zone 7 a vent conduit 80 is included to cool and reduce the liquid content, such as water, of the mixture before exiting the extruder. An optional vent stuffer, commercially available from APV Baker, may be used to prevent the polymer melt composition from leaving through vent 80. The flow of the polymer melt composition through barrel 74 is from zone 1. that comes out of barrel 74 in zone 8.

A screw configuration and mixing element for the twin screw extruder is schematically illustrated in Figure 10B. The twin screw extruder comprises a plurality of double screws (TLS) (designated A and B), vanes (designated C) and double inverted thread screws (RTLS) (designated D) installed in series, as illustrated in Table 2 below.

Table 2 The screw elements (A-B) are characterized by the number of continuous spindles and the passage of these. A spindle is a blade (at a given helix angle) that wraps around the core of the screw. The number of spindles indicates the number of blades that wrap the core at a given point in the length of the screw. By increasing the number of spindles the volumetric capacity of the screw is reduced and the capacity of pressure generation of the screw is increased.

The pitch of the screw is the distance necessary for a blade to complete a revolution of the core. It is expressed as the number of diameters of a screw per one full revolution of a blade. By decreasing the pitch of the screw the pressure generated by it increases and its volumetric capacity is reduced.

The length of a screw is reported as the length ratio of the element divided by the diameter of the same.

In this example, TLS and RTLS are used. The type of screw A is a TLS with a step of 1.0 and variable length relationships. The type of screw B is a TLS with a step of 0.5 and variable length ratios.

The double lug palettes C, which serve as mixing elements, are also included in series with the TLS and RTLS screw elements to improve mixing. The blade C has a length ratio of 1/4. To control the flow and the corresponding mixing time, various configurations of double lug pallets and inverted thread elements D are used, as well as single and double screws threaded in the opposite direction. Screw D is an RTLS with a pitch of 0.5 and a length ratio of 0.5.

In zone 1, the hydroxyl polymer is fed into the solids feed port at a rate of 230 grams / minute through the use of a weight loss feeder K-Tron (Pitman, NJ). This hydroxyl polymer is combined within the extruder (zone 1) with water, an external plasticizer, added to the liquid fed at a rate of 146 grams / minute through the use of a Milton Roy diaphragm pump (Ivyland, PA) [ pump head 7.2 l / h (1.9 gallons per hour)] to form a slurry of hydroxyl polymer / water. This slurry then goes down the barrel of the extruder and cooks. Table 3 below describes the corresponding temperature, pressure and function of each zone of the extruder.

Table 3 After the slurry has left the extruder, part of the melt-processed hydroxyl polymer is discharged, and another part (100 g) is fed to a Zenith® equipment, type PEP II (Sanford NC) and pumped to a static mixer SMX style (Koch-Glitsch, Woodridge, Illinois). The static mixer is used to combine additives, such as in the case of a crosslinking agent, a crosslinking facilitator, an external plasticizer such as water, with the hydroxyl polymer melt processed. The additives are pumped into the static mixer by means of PREP 100 HPLC pumps (Chrom Tech, Apple Valley MN). These pumps provide an addition capacity of low volume and high pressure. The polymeric fusion composition of the present invention is ready to be processed by a processing operation of polymers.

Filament synthesis A non-limiting example of a process for producing filaments is to process a polymeric melt composition of the present invention with polymers.

As used herein, "polymer processing" refers to any operation and / or process in which, from a polymer melt composition, a filament comprising a processed hydroxyl polymer is formed. Non-limiting examples of polymer processing operations include extrusion, molding and fiber spinning. Extrusion and molding (by casting or blowing) typically produce films, canvases and extrusions of various profiles. The molding may include injection molding, blow molding and compression molding. Fiber spinning may include spunbonding, blow melt, spinning yarn, continuous filament formation and / or tow fiber formation. As used herein, the term "processed hydroxyl polymers" refers to any hydroxyl polymer that has been exposed to a melt processing operation and to a polymer processing operation subsequent thereto.

Next, an example of a process for producing a filament of the present invention from a polymeric fusion composition of the present invention follows.

A polymeric fusion composition is prepared in accordance with the synthesis of a polymeric fusion composition described above. The polymeric melt composition present in the double-screw extruder is pumped to a meltblown matrix by means of a suitable pump, eg, Zenith, © type PEP II, with a capacity of 10 cubic centimeters per revolution ( cc / rev), manufactured by Parker Hannifin Corporation, Zenith Pumps division, of Sanford, NC, USA. UU The hydroxyl polymer, such as starch, flowing to the meltblown matrix is controlled by adjusting the number of revolutions per minute (rpm) of the pump. The tubes that connect the extruder, the pump, the blow-melt matrix and, optionally, a mixer are heated with electricity and controlled with a thermostat at 65 ° C.

The meltblown matrix has several rows of circular extrusion nozzles spaced apart at a pitch P of about 24,000 mm. The nozzles are arranged in a stepped grid having a spacing of approximately 2,489 mm inside the rows and a spacing of 2,159 mm between the rows. The nozzles 200 have an inner diameter of approximately 0.254 mm and an individual outer diameter of approximately 0.813 mm. Each individual nozzle is surrounded by an annular hole formed in an orifice plate having a thickness of approximately 1.9 mm. A configuration of a plurality of holes in the orifice plate corresponds to a pattern of extrusion nozzles in the meltblown matrix. Once the orifice plate is combined with the melt blow molds, the resulting area for air flow is about 36 percent. The plate is fixed so that the filaments that are extruded through the extrusion nozzles are surrounded and attenuated by humidified air streams, generally cylindrical, supplied through the holes in the orifice plate. Extrusion nozzles may extend from a distance of about 1.5 mm to about 4 mm and, more specifically, from about 2 mm to about 3 mm, beyond the outer surface of the orifice plate. A plurality of peripheral layer air holes are formed by connecting the extrusion nozzles to two outer rows on each side of the plurality of extrusion nozzles, seen in plan, so that each air hole in the peripheral layer comprises a hole annular described above. Additionally, each of the other rows and columns of the remaining extrusion nozzles are blocked, which increases the spacing between the active extrusion nozzles.

The attenuation air for attenuating the filaments that are produced through the extrusion nozzles can be provided by heating compressed air with a heater with electrical resistance, e.g. eg, a heater manufactured by Chromalox, Division of Emerson Electric, of Pittsburgh, PA, USA. UU An appropriate amount of steam is added at an absolute pressure of about 240 to about 420 kilopascals (kPa) controlled by a balloon valve to saturate or practically saturate the hot air to the conditions of the electrically heated and thermostatically controlled supply tube. The condensate is removed in an electrically heated separator controlled by a thermostat. The absolute pressure of the attenuation air is about 130 kPa to about 310 kPa measured in the controlled supply tube. The filaments that are extruded from the extrusion nozzles have a moisture content of about 20% and / or from about 25% to about 50% and / or about 55% by weight. The filaments are dried by a drying air stream with a temperature of about 149 ° C to about 315 ° C which comes from an electric resistance heater, is supplied through drying nozzles and is discharged at an angle, generally, perpendicular to the general orientation of the filaments that are being extruded. The moisture content of the filaments is reduced from about 45% to about 15% (ie, from a consistency of about 55% to about 85%), and the fibers are collected in a collection device, e.g. eg, a as a mobile porous band.

The parameters of the process for manufacturing the filaments of the present invention are set forth in Table 4.

Shows Units: Value Air flow rate of attenuation g / min 9000 Attenuation air temperature ° C 65 Flow rate of attenuation current g / min 1800 Gauge pressure of attenuation kPa 213 Gauge pressure of attenuation in the supply pipe kPa 14 Attenuation output temperature ° C 65 Speed of the solution pump revs / min 12 Solution flow g / min / hole 0.18 Drying air flow rate g / min 17000 Type of air duct Slots Dimension of air duct MM 356 x 127 Speed through the static tube Pitot m / s 65 Drying air temperature in heater ° C 260 Position of the dry pipe from the pipe MM 80 Duct line angle relative to grade 0 fibers Spacing between the drying ducts MM 205 Distance between the matrix and the MM 610 forming box Length of the forming box in machine direction MM 635 Width of the forming box in cross direction MM 380 Flow rate of the forming box g / min 41000 Table 4 A crosslinking system by a crosslinking agent, such as an imidazolidinone, can crosslink the hydroxyl polymers together to provide the filament with wet strength, with or without subjecting it to a curing step. The crosslinking occurs so that the polymer melt composition can be supplied through the extrusion nozzles and produce filaments. In other words, the crosslinking system does not prematurely crosslink the hydroxyl polymers in the polymer melt composition, which would clog the extrusion nozzles, and the filaments could not be produced.

The filaments of the present invention do not include coatings or other surface treatments that are applied to a pre-existing form, such as a coating on a fiber, film or foam. However, in one embodiment of the present invention, the surface of a filament according to the present invention can be coated or treated with the crosslinking system of the present invention.

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

Additionally, the filaments can be further cured at room temperature for days, either after curing them at a temperature above room temperature or instead of curing them at a temperature above room temperature.

The filaments of the present invention can include filaments spunbond and / or spunbond, hollow filaments, shaped filaments, such as multi-lobed filaments and multicomponent filaments, especially bicomponents. The configuration of multicomponent filaments, especially bicomponents, can be parallel, sheath-core, segmented sectors, bead or islets or any combination of these. The sheath can be discontinuous or continuous around the nucleus. The weight ratio of the sheath to the core can be about 5:95 to about 95: 5. The filaments of the present invention may have different geometries including round, elliptical, profiled, rectangular and other rare shapes.

Non-limiting example of a fibrous structure Example 1 - Fibrous structure comprising starch filaments / wood pulp fibers A polymeric fusion composition comprising 7.5% of Mowiol 10-98 commercially available from Kuraray Co. (polyvinyl alcohol), 19% Ethylex 2035 commercially available from Tate & Lyle (ethoxylated starch), 19% CPI 050820-156 commercially available from Com Products International (starch diluted with acid), 0.5% sulfosuccinate surfactant, such as Aerosol AOT, commercially available from Cytec Industries, 0.25% Hyperfloc NF221 available commercially available from Hychem, Inc. (polyacrylamine), 3.25% imidazolidinone crosslinking agent (DHEU), and 0.5% ammonium chloride available from Aldrich (crosslinking facilitator). The molten composition is cooked and extruded from a co-rotating twin screw extruder at approximately 50% solids (50% H20), as described above.

The polymeric melt composition is then pumped to a series of blow-melt nozzle heads at different angles with respect to the machine direction to provide a plurality of filaments from each spinneret. The filaments of each nozzle head are attenuated with a stream of saturated air to form a layer of filaments that are collected on one another to form a nonwoven fabric substrate. The filaments of two or more of the Filament layers have different orientations with respect to the machine direction. The formed nonwoven fabric substrate has a basis weight of about 10 g / m2 to about 120 g / m2, as described above. The filaments are dried by cction drying before being deposited on a web to form the non-woven fabric substrate. These filaments formed by melting and extrusion are virtually continuous filaments.

If two or more nozzle heads are used to form a filament source, such as two or more adjoining nozzle heads together, the nozzle head assembly can be formed by abutting a first nozzle head with a second nozzle head., so that the maximum distance between the seam opening of the filament-forming nozzle in the first nozzle head and the seam opening of the filament-forming nozzle in the second nozzle head is less than 9 mm and / or less than 7 mm and / or less than 5 mm. In addition to the adjoining nozzle heads, an air plate is used in the set of these nozzle heads to cover the seam formed by the adjoining nozzle heads. The purpose of the air plates is to produce an air flow that prevents the filaments produced by the row units from colliding with the adjacent filaments, which could cause the filaments and / or heads of the row units to be linked .

Wood pulp fibers, Southern Kraft softwood (SSK) commercially available from Georgia Pacific as crushed pulp, are disintegrated with a crusher and transported with a blower to an air laying former commercially available from Dan-Web. The wood pulp fibers are deposited on a surface of a non-woven fabric substrate with solid additives.

The additional polymeric melt composition is pumped to a head of additional blow-melt nozzles which is oriented at an angle of approximately 90 ° with respect to the machine direction to produce an additional filament layer (which is a lightweight fabric), which is deposited on the wood pulp fibers for locating these wood pulp fibers between the nonwoven fabric substrate and the light fabric to form a fibrous structure. The lightweight fabric typically has a basis weight of about 0.1 g / m2 to about 10 g / m2.

The fibrous structure is then subjected to a binding process, wherein the binding sites are formed between the nonwoven substrate and the lightweight tissue, so that the wood pulp fibers are located between the nonwoven substrate and the lightweight tissue to form a finished fibrous structure. The joining process can be used to impart a pattern to the finished fibrous structure, and / or the finished fibrous structure can be engraved. The fibrous structure can be subjected to humidification during the manufacturing process of the fibrous structure, e.g. eg, before joining and / or engraving.

The finished fibrous structure is subsequently wound twisted around a core to produce a sanitary paper product.

The fibrous structure, the finished fibrous structure and / or the sanitary paper product incorporating the finished fibrous structure has a tensile ratio of 2 or less.

Test methods Unless otherwise specified, all of the tests described in the present invention, including those described in the Definitions section and the following test methods, are carried out with samples that were conditioned in an air-conditioned room. ± temperature of 23 ° C ± 1.0 ° C and a relative humidity of 50% ± 2% for a minimum of 2 hours before the test. The Tested samples are "usable units". "Usable units", as used in the present description, means sheets, flat surfaces of the raw material roll, preconverted flat surfaces and / or single-leaf or multi-leaf products. All the tests were carried out in the same environmental conditions and in said conditioned room. Samples that have defects such as wrinkles, tears, holes and the like are not tested. Conditioned samples as described in the present description are considered dry samples (such as "dry filaments") for testing purposes. All instruments are calibrated according to the manufacturer's specifications.

Basis weight test method The basis weight of a fibrous structure is measured in stacks of twelve usable units with the use of an upper load analytical balance with a resolution of ± 0.001 g. The balance is protected from drafts and other disturbances with the use of a surge protector. A precision cutting matrix measuring 8.9 cm ± 0.0089 cm by 8.9 cm ± 0.0089 cm (3,500 in. + 0.0035 in. By 3,500 in. ± 0.0035 in.) Is used to prepare all samples.

With a precision cut matrix, the samples are cut into squares. The cut squares combine to form a stack with a thickness of twelve samples. The mass of the sample pile is measured and the result is recorded up to the nearest 0.001 g.

The basis weight is calculated in pounds / 3000 ft2 or g / m2 as follows: Base weight = (mass of the stack) / [(area of 1 square in the stack) x (number of squares in the stack)] For example Base weight (pounds / 3000 ft2) = [[pile mass (g) / 453.6 (g / pounds)] / [12.25 (inches2) / 144 (inches2 / ft2) x 12]] x 3000 or Base weight (g / m2) = pile mass (g) / [79,032 (cm2) / 10,000 (cm2 / m2) x 12] The result is reported up to 0.1 pounds / 3000 ft2 or 0.1 g / m2 closer. The dimensions of the samples can be modified or varied with the use of a precision cutter similar to the one mentioned above, so that there are at least 645.16 square centimeters (100 square inches) of sample area in the pile.

Test method of dry tensile strength The tensile strength is determined at a constant rate of extension of the tensile tester with a computer interface (a suitable instrument is the EJA Vantage of Thwing-Albert Instrument Co. Wet Berlin, NJ) with a load cell for which the measured forces are within 10% to 90% of the cell boundary. Movable (upper) and fixed (lower) pneumatic clamps are fitted with smooth-faced, stainless steel fasteners with a suitable design for testing sheet material 2.54 cm (1 in) wide (Thwing-Albert item # 733GC ). An air pressure of approximately 60 psi is supplied to the jaws.

Eight usable units of fibrous structures are divided into two stacks of four usable units each. The usable units in each stack are oriented consistently with respect to the machine direction (MD) and the cross direction (CD). One of the batteries is assigned for tests on the MD and the other for tests on the CD. With a 2.54 cm (one inch) precision cutter (Thwing-Albert JDC-1 -10 or similar), take a stack on CD and cut a stack of 2.54 cm ± 0.025 cm (1.00 inch ± 0.01 inch) strips ) wide by 3 - 4 inches long (longitudinal dimension on CD). In the same way, the remaining MD stack (the longitudinal dimension of the MD strip) is cut to achieve a total of 8 samples, four CD strips and four MD strips. Each strip to be tested has the thickness of a usable unit, and it will be treated as a sample unit for the test.

The traction meter is programmed to perform an extension test, the strength and extension data are collected at a pick up speed of 20 Hz as the crosshead is raised at a speed of 5.08 cm / min (2.00 inches / min) until the sample breaks. The sensitivity to break is set at 80%, that is, the test ends when the measured force drops to 20% of the maximum peak force, after which the crosshead is returned to its original position.

The reference length is set at 2.54 cm (.00 inch). The crosshead and the load cell are set to zero. The sample is inserted into the open top and bottom fasteners so that at least 1.3 cm (0.5 in) of the length of the sample is contained in each fastener. Align the sample vertically inside the upper and lower clamps and then close the upper clamp. Check that the sample is aligned, and close the lower fastener. The sample should be fairly straight between the fasteners with a force not greater than 5.0 g in the load cell. The traction meter and the information collection are started. The tests are repeated similarly for the four samples on CD and four on MD.

The software is programmed to calculate the following data from the strength curves (g) according to the extension (inch) prepared: The tensile strength is the maximum peak force (g) divided by the sample width (1 inch) and reported as g / inch at the nearest 0.0038 N / cm (1 g / inch).

The tensile strength (g / inch) is calculated for the four sample units in CD and the four sample units in MC. An average is calculated for each parameter separately for the samples on CD and MD.

Calculations: Tensile ratio = tensile strength in MD (g / inch) / tensile strength in CD (g / inch) The dimensions and values described in the present description should not be understood as strictly limited to the exact numerical values mentioned. Instead, unless otherwise specified, each of these dimensions will refer to both the aforementioned value and a functionally equivalent range comprising that value. For example, a dimension described as "40 mm" refers to "approximately 40 mm." All documents mentioned in the present description, including any cross reference or patent or related application, are incorporated in the present description in their entirety as a reference, unless expressly excluded or limited in any other way. The mention of any document is not an admission that it constitutes a prior matter with respect to any invention described or claimed herein or that by itself, or in any combination with any other reference or references, teach, suggest or describe said invention. In addition, to the extent that any meaning or definition of a term in this document contradicts any meaning or definition of the same term in a document incorporated by reference, the meaning or definition assigned to that term in this document shall govern.

Although particular embodiments of the present invention have been illustrated and described, it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention. Therefore, the appended claims are intended to cover all those modifications and changes that fall within the scope of this invention.

Claims

1. A fibrous structure comprising a plurality of filaments comprising one or more polysaccharides, further characterized in that the fibrous structure has a tensile ratio of 2 or less, measured in accordance with the dry tensile strength method described in the present invention .

2. The fibrous structure according to claim 1, further characterized in that at least one of one or more polysaccharides is selected from the group consisting of: starch, starch derivatives, starch copolymers, chitosan, chitosan derivatives, chitosan copolymers, cellulose , cellulose derivatives, cellulose copolymers, hemicellulose, hemicellulose derivatives, hemicellulose copolymers and mixtures thereof, preferably, wherein at least one or more polysaccharides is selected from the group consisting of: starch, starch derivatives, starch copolymers and mixtures thereof, more preferably, wherein at least one polysaccharide comprises ethoxylated starch or starch diluted with acid.

3. The fibrous structure according to claim 1 or 2, further characterized in that at least one of the filaments comprises a hydroxyl polymer selected from the group consisting of: polyvinyl alcohol, polyvinyl alcohol derivatives, polyvinyl alcohol copolymers, gums, arabinans, galactanas, proteins and mixtures of these.

4. The fibrous structure according to any of the preceding claims, further characterized in that at least one of the filaments comprises a polymer selected from the group consisting of: polyacrylamine and its derivatives; polyacrylic acid, polymethacrylic acid, and their esters; polyethyleneimine; copolymers made from mixtures of polymer monomers aforementioned; and mixtures thereof, preferably, wherein the polymer has an average molecular weight greater than 500,000 g / mol, more preferably, wherein the polymer comprises polyacrylamine.

5. The fibrous structure according to any of the preceding claims, further characterized in that at least one of the filaments comprises a surfactant, preferably, wherein the surfactant comprises a sulfosuccinate surfactant.

6. The fibrous structure according to any of the preceding claims, further characterized in that the fibrous structure exhibits a basis weight of 10 g / m2 to 120 g / m2.

7. The fibrous structure according to any of the preceding claims, further characterized in that the fibrous structure further comprises one or more solid additives.

8. The fibrous structure according to any of the preceding claims, further characterized in that at least one of the one or more solid additives comprises a fiber, preferably, wherein the fiber comprises a pulp fiber, more preferably, wherein the fiber of pulp is selected from the group consisting of hardwood pulp fibers, softwood pulp fibers and mixtures thereof, even more preferably, wherein the pulp fiber comprises a fiber of eucalyptus pulp or a treated pulp fiber chemically

9. The fibrous structure according to any of the preceding claims, further characterized in that one or more of the solid additives are present on a surface of the fibrous structure.

10. The fibrous structure according to claim 9, characterized in addition, because the fibrous structure further comprises a light weave connected to the surface of the fibrous structure, such that the solid additives are located between the light weave and the surface of the fibrous structure, more preferably, where the material of light weave is attached to the surface of the fibrous structure at one or more binding sites, even more preferably, wherein one or more bonding sites comprises a thermal bond or a pressure bond.

11. The fibrous structure according to claim 10, further characterized in that the lightweight material is bonded to the surface of the fibrous structure by a plurality of different bonding sites.

12. The fibrous structure according to any of the preceding claims, further characterized in that the fibrous structure is engraved.

13. The fibrous structure according to any of the preceding claims, further characterized in that the fibrous structure has a density of less than 0.60 g / cm 3.

14. A single or multi-sheet sanitary paper product comprising a fibrous structure according to the preceding claims.

15. A method for manufacturing a fibrous structure according to any of the preceding claims; The method comprises the steps of: to. providing a plurality of filaments from a filament source; Y b. collecting the filaments in a collection device to form a fibrous structure, such that the fibrous structure has a tensile ratio of 2 or less, measured in accordance with the tensile test method described in the present description, preferably , characterized further because the method comprises the steps of: c. providing a plurality of solid additives from a solid additive source, such that the solid additives are collected on a surface of the fibrous structure, more preferably, further characterized in that the method further comprises the steps of: d. provide a light fabric of material; Y and. attaching the light weave of material to the surface of the fibrous structure, such that the solid additives are located between the light weave material and the surface of the fibrous structure.