Abstract: The present invention is directed to products, such as paper and paperboard products, comprising a substrate containing cellulose and top ply comprising microfibrillated cellulose and inorganic particulate, to methods of making such paper and paperboard products, and associated uses of such paper and paperboard products. The microfibrillated cellulose and inorganic particulate material are applied at the stage when the wet substrate is in the process of being formed on the wire of a papermaking machine, thereby avoiding the additional cost of more extensive equipment and machinery as well as in separate drying of a coating. The microfibrillated cellulose facilitates the application of inorganic particulate onto the surface of a wet paper or paperboard substrate when applied thusly, by trapping the inorganic particulate on the surface of the substrate and by giving the composite sufficient strength and a suitable pore structure to make it suitable for printing and other end-use demands.

Abstract: A coated paperboard container includes a paperboard substrate and an aqueous barrier coating on the paperboard substrate. The coated paperboard container has a repulpability yield of 75% accepts or greater, a sidewall seam bond strength of 30 pounds per inch or greater, and a wet rigidity loss of 50% or less.

Abstract: A method for manufacturing a multi-layered paperboard is disclosed, which includes at least two fibrous layers, in which method at least one layer of the multi-layered paperboard is treated by applying an aqueous solution of a first strength component in dissolved form including anionic strength polymer and/or amphoteric strength polymer composition on a surface of layer, and an aqueous solution of a cationic second strength component in dissolved form is added to a fibre stock from which at least one of the fibrous layers joined together is formed.

Abstract: A repulpable paper strap includes a plurality of paper strings, and a binder that binds the paper strings together, the binder including a partially hydrolyzed polyvinyl alcohol and a fully hydrolyzed polyvinyl alcohol. Related methods of forming the repulpable paper strap is also provided.

Abstract: A method for forming a multi-ply fiber web in which least part of the sizing of the multi-ply fiber web is provided by applying sizing agent in the form of foam by a curtain type application device (C10, C20) in between at least two layers of the multi-ply fiber web in the forming section. The invention also relates to a forming section for a multi-ply fiber web having at least one twin-wire forming part formed between a wire (10) for the bottom layer and a wire (20) for the top layer of the multi-ply fiber web, where the layers are joined, and the treated layers combined. The forming section has a curtain type application device (C10, C20) for applying sizing agent in the form of foam in between two layers of the multi-ply fiber web in the forming section of a multi-ply fiber web production line.

Abstract: A method for making a packaging material includes jetting a first pulp stock onto a wire to form a strength layer precursor including water; and softwood fibers, the first pulp stock excluding a water soluble di-valent or multi-valent salt. A second pulp stock is jetted onto a second wire to form an image layer precursor including water; hardwood fibers; and a water soluble di-valent or multi-valent salt present in an amount ranging from about 5 lb per ton of total fibers in the second pulp stock to about 50 lb per ton of the total fibers in the second pulp stock. The image layer precursor and the strength layer precursor are placed in contact. Water is removed from the image and strength layer precursors. The image layer precursor and the strength layer precursor are dried to form the packaging material including an image layer and a strength layer.

Abstract: A multi-ply bath tissue includes a first ply providing a first surface of the bath tissue. The first ply includes first and second layers. The first layer forms the first surface and includes a temporary wet strength resin. The second layer is substantially free from a temporary wet strength resin. A second ply provides a second surface of the bath tissue. The second ply includes first and second layers. The first layer forms the second surface and includes a temporary wet strength resin. The second layer is substantially free from a temporary wet strength resin. The bath tissue is free from regenerated cellulosic microfibers.

Abstract: A method of manufacturing a film comprising microfibrillated cellulose, wherein the method comprises the steps of: providing a first suspension comprising microfibrillated cellulose, having a dry content of from 0.2 to 2.0%, wherein the first suspension has a first Schopper-Riegler (SR) value; forming a first web of said suspension; at least partly dewatering said first web; applying a second suspension comprising microfibrillated cellulose, and/or fines and/or fibers onto a surface of said formed and at least partially dried first web, wherein the second suspension has a second Schopper-Riegler value which is higher than said first Schopper-Riegler value, thereby forming a film.

Abstract: A method for manufacturing a film, wherein said film has a basis weight of less than 50 g/m2 and wherein the density of the film is higher than 750 kg/m2 comprising the steps of: providing a suspension comprising microfibrillated cellulose (MFC); forming a web of said suspension on a porous wire, microfibrillated cellulose (MFC); surface sizing said web, wherein the web, at the beginning of the surface sizing step, has a moisture content in the range of from 10 to 50 wt-%; drying said surface sized web to a final moisture content of between 0.1-20 wt-% to form said film.

Abstract: A multi-ply bath tissue includes a first ply providing a first surface of the bath tissue. The first ply includes first and second layers. The first layer forms the first surface and includes a temporary wet strength resin. The second layer is substantially free from a temporary wet strength resin. A second ply provides a second surface of the bath tissue. The second ply includes first and second layers. The first layer forms the second surface and includes a temporary wet strength resin. The second layer is substantially free from a temporary wet strength resin. The bath tissue is free from regenerated cellulosic microfibers.

Abstract: A multi-ply bath tissue includes a first ply forming a first surface of the bath tissue. The first ply includes first and second layers. A second ply forms a second surface of the bath tissue. The second ply includes first and second layers. At least one of the first and second layers of at least one of the first ply and the second ply includes a temporary wet strength resin. The bath tissue has a cross machine direction (CD) wet tensile strength of between about 50 grams to about 90 grams.

Abstract: A hydrophobically sized fibrous web layer, preparation of a fibrous web or a fiber-based coating, a multilayer board product having at least a middle layer formed of said fibrous web, as well as use of a heat-sensitive surfactant for said methods and products, whereby microfibrillated cellulose (MFC) and hydrophobic size are brought to a foam with water and the heat-sensitive surfactant, the foam is supplied to a forming fabric of a paper or board machine, dewatered by suction of air through the forming fabric, and dried to a web product. Alternatively the foam may be supplied onto a premade fibrous web and dried to form a coating layer. The hydrophilic functionality of the surfactant contained in the web may be destroyed by heating. Pulp of a greater fiber length, such as CTMP, may be included, to provide improved wet and dry tensile strength for the paper and board products.

Abstract: Wiping products, such as facial tissues, contain a temperature change composition that can provide a cooling sensation when contacted with the skin of a user. The temperature change composition is structured emulsion that may include a phase change material, a carrier, a surfactant, and a crystalline initiator. The phase change materials, in one embodiment, can have a relatively high heat of fusion. When undergoing a phase change, the temperature change composition absorbs heat and thereby provides a cooling feeling or cooling sensation to the skin of a user.

Abstract: A method for manufacturing cellulosic material includes: introducing cellulose fibers as cellulosic raw material to a system, conveying the cellulose fibers to an extruder comprising a mixing part and/or a refining part, dosing at least one chemical to the system before the extruder and/or in the extruder and performing a reaction between the cellulose fibers and the chemical(s) at least partly in the extruder, wherein the reaction is performed at a consistency of at least 40%, and/or dosing at least one chemical to the system before the extruder and/or in the extruder and mixing the cellulose fibers and the chemical(s) in the mixing part of the extruder, wherein the mixing step is performed at a consistency of at least 40%, and/or refining the introduced cellulose fibers at least partly in the refining part of the extruder, wherein the refining step is performed at a consistency of at least 5%.

Abstract: A multi-ply bath tissue includes a first ply forming a first surface of the bath tissue, the first ply including first and second layers, and a second ply forming a second surface of the bath tissue, the second ply including first and second layers. At least one of the first and second layers of at least one of the first ply and the second ply includes a temporary wet strength resin, at least another one of the first and second layers of at least one of the first ply and the second ply is free from a temporary wet strength resin. The bath tissue has a cross machine direction (CD) wet tensile strength of between about 50 grams to about 90 grams.

Abstract: A multi-ply bath tissue includes a first ply providing a first surface of the bath tissue. The first ply includes first and second layers. The first layer of the first ply forms the first surface. The first layer of the first ply includes a temporary wet strength resin. The second layer of the first ply is substantially free from a temporary wet strength resin. A second ply provides a second surface of the bath tissue. The second ply includes first and second layers. The first layer of the second ply forms the second surface. The first layer of the second ply includes a temporary wet strength resin. The second layer of the second ply is substantially free from a temporary wet strength resin. The bath tissue has a CD wet tensile strength of between about 55 grams to about 75 grams.

Abstract: A multi-ply bath tissue includes a first ply providing a first surface of the bath tissue. The first ply includes first and second layers. The first layer of the first ply forms the first surface. The first layer of the first ply includes a temporary wet strength resin. The second layer of the first ply is substantially free from a temporary wet strength resin. A second ply provides a second surface of the bath tissue.

Abstract: Wiping products, such as facial tissues, contain a temperature change composition that can provide a cooling sensation when contacted with the skin of a user. The temperature change composition, for instance, can contain one or more phase change agents that undergo a phase change at slightly elevated temperatures. The phase change agents, in one embodiment, can have a relatively high heat of fusion. When undergoing a phase change, the phase change agents absorb heat and thereby provide a cooling feeling to the skin of a user. In one embodiment, the phase change agent comprises a straight chain hydrocarbon. Hydrocarbons useful as phase change agents include an octadecane, a nonadecane, a heptonoate, or mixtures thereof.

Abstract: A multi-ply absorbent sheet of cellulosic fiber includes continuous outer surfaces, and an absorbent core between the outer surfaces. The absorbent core includes a non-woven fiber network comprising a plurality of pileated fiber enriched regions of a relatively high local basis weight interconnected by way of a plurality of lower local basis weight linking regions whose fiber orientation is biased along the direction between pileated fiber enriched regions, interconnected thereby, and a plurality of fiber-deprived cellules between the fiber enriched regions and the linking regions, also being characterized by a local basis weight lower than that of the fiber enriched regions.

Abstract: Wiping products, such as facial tissues, contain an interior temperature change composition and an exterior hydrophilic lotion composition that can provide a cooling sensation when contacted with the skin of a user. The temperature change composition, for instance, can contain one or more phase change agents that undergo a phase change at slightly elevated temperatures. The phase change agents, in one embodiment, can have a relatively high heat of fusion. When undergoing a phase change, the phase change agents absorb heat and thereby provide a cooling feeling to the skin of a user. The hydrophilic lotion composition may contain a carrier and a thermo-reversible gelling agent. The hydrophilic lotion composition maintains the temperature change composition within the tissue and helps to prevent skin irritation.

Abstract: A multi-ply bath tissue that is both soft and durable. The multi-ply bath tissue can include first and second plies, each of which includes two layers. A temporary wet strength resin is provided in the layers of the first and second plies that form the surfaces of the bath tissue. The bath tissue has an excellent combination of low wet abrasion and CD wet tensile, and softness that is demonstrably better than comparative products.

Abstract: A multi-ply bath tissue that is both soft and durable. The multi-ply bath tissue can include first and second plies, each of which includes two layers. A temporary wet strength resin is provided in the layers of the first and second plies that form the surfaces of the bath tissue. The bath tissue has an excellent combination of low wet abrasion and CD wet tensile, and softness that is demonstrably better than comparative products.

Abstract: The invention proposes an embossed sheet (10) comprising at least one ply (12) of tissue having an embossing pattern comprising at least one series of protuberances (18) formed projecting from one surface of the said ply (12) of tissue, and at least one ply joined to the said at least one ply (12) of tissue and located opposite the said surface of the ply (14) of water-soluble material, characterized in that the ply (14) of water-soluble material is joined to the said at least one ply (12) of tissue at the summits (18a) of at least part of the protuberances (18). The invention also proposes a method for manufacturing such a multi-ply sheet (10).

Abstract: A manufacturing method of a security paper material, in particular for labelling and packaging, comprising the steps of forming a paper sheet from a wet cellulose fiber pulp and providing the paper sheet with electronic chips; the chips are introduced into the paper sheet being formed during the transformation step of the pulp into paper and are deposited directly onto the wet pulp and at least partially embedded in the pulp. Optionally, an auxiliary paper sheet is coupled to the paper sheet provided with the chips so that the chips are incorporated between the two sheets.

Abstract: Flame retardant composite materials are provided which include at least one first paper which comprises carbon nanofibers and graphite oxide particles. The composite materials may further include at least one second paper which comprises carbon nanofibers. The composites may further include one or more structural material layers sandwiched between the first and second papers. Occupant structures are also provided with fire and smoke retardant surfaces composed of carbon nanofibers/graphite oxide particles papers at least partially surrounding occupants of the occupant structures.

Abstract: A paper includes a paper body containing pulp fibers, a low electric-resistance region provided in a layer inside the paper body and being lower than the paper body in electric resistivity, and magnetic bodies arranged inside the low electric-resistance region and having a large Barkhausen effect.

Abstract: The invention provides a three layered reprographic paper having improved strength, stiffness and curl resistance properties, and a method for making same. The paper has a central core layer made largely of cellulose and bulked with a bulking agent such as a diamide salt. A starch-based metered size press coating is pressed on both sides of the core layer, wherein the starch has a high solid content. The coating forms a three layered paper having an I-beam arrangement with high strength outer layers surrounding a low density core.

Abstract: The present invention relates to a process for producing a paper or paperboard product which process comprises the steps of providing a first headbox with a furnish comprising fibers, which furnish forms at least one layer of the paper or paperboard product, providing the headbox with a non-fibrous high consistency composition, which composition forms at least one additional layer of the paper or paperboard product and conducting the layers onto a wire forming a multilayer web which is further dewatered and dried forming the paper or paperboard product. The invention further relates to a paper or paperboard produced according to the process and a headbox used in the process.

Abstract: The invention proposes an embossed sheet (10) comprising at least one ply (12) of tissue having an embossing pattern comprising at least one series of protuberances (18) formed projecting from one surface of the said ply (12) of tissue, and at least one ply joined to the said at least one ply (12) of tissue and located opposite the said surface of the ply (14) of water-soluble material, characterized in that the ply (14) of water-soluble material is joined to the said at least one ply (12) of tissue at the summits (18a) of at least part of the protuberances (18). The invention also proposes a method for manufacturing such a multi-ply sheet (10).

Abstract: Wiping products, such as facial tissues, contain an interior temperature change composition and an exterior hydrophilic lotion composition that can provide a cooling sensation when contacted with the skin of a user. The temperature change composition, for instance, can contain one or more phase change agents that undergo a phase change at slightly elevated temperatures. The phase change agents, in one embodiment, can have a relatively high heat of fusion. When undergoing a phase change, the phase change agents absorb heat and thereby provide a cooling feeling to the skin of a user. The hydrophilic lotion composition may contain a carrier and a thermo-reversible gelling agent. The hydrophilic lotion composition maintains the temperature change composition within the tissue and helps to prevent skin irritation.

Abstract: A paper includes a paper body containing pulp fibers, a low electric-resistance region provided in a layer inside the paper body and being lower than the paper body in electric resistivity, and magnetic bodies arranged inside the low electric-resistance region and having a large Barkhausen effect.

Abstract: Fibers having a plurality of colored regions printed on front and rear sides of said fiber are disclosed, wherein the colors are visible only under ultra-violet light. The regions may be in the form of stripes or may be arranged in a pseudo-random pattern. The regions may be differently colored. Such fibers can be incorporated into paper products as a form of counterfeit protection.

Abstract: Fibers (2, 14) having a plurality of colored regions printed on front and rear sides of said fiber are disclosed, wherein the colors are visible only under ultra-violet light. The regions may be in the form of stripes (4, 6, 8, 10 and 12) or may be arranged is a pseudo-random pattern (16, 18, 20, 22, 24). The regions may be differently colored. Such fibers can be incorporated into paper products as a form of counterfeit protection.

Abstract: A fibrous sheet having a basis weight of between 20 and 1000 g/m2 that disintegrates in water, has 10% to 70% starch on the basis of the total weight of the dry fibrous sheet. The disintegration time in water, measured in accordance with standard NF Q34-020 applied to a specimen of the sheet of 9×8 cm2, is less than 50 seconds. A loss of strength of the sheet measured in accordance with a defined table test corresponds to a loss of strength of a specimen of said sheet forming an angle of at least 85°, after having being wetted with water for a duration of 6 seconds, and/or a residual wet strength of the sheet relative to its dry strength, as measured according to a defined ring crush test, is less than 1%. The fibrous sheet may be used for the manufacture of a water disintegrable core in a roll of tissue paper.

Abstract: The invention relates to a method of producing a laminate paper product comprising at least two layers, said method comprising (i) providing an aqueous suspension comprising cellulosic fibers (ii) adding to the suspension microfibrillar polysaccharide in an amount to yield from about 0.05 to about 50 wt % based on the weight of the cellulosic fibers (iii) dewatering the obtained suspension and forming a first layer having a density from about 150 to about 500 kg/m3 of said laminate paper product. The invention also relates to a method comprising (i) providing an aqueous suspension comprising cellulosic fibers (ii) adding to the suspension microfibrillar polysaccharide in an amount to yield from about 0.

Abstract: The present invention relates to a process for producing a paper or paperboard product which process comprises the steps of providing a first headbox with a furnish comprising fibres, which furnish forms at least one layer of the paper or paperboard product, providing the headbox with a non-fibrous high consistency composition, which composition forms at least one additional layer of the paper or paperboard product and conducting the layers onto a wire forming a multilayer web which is further dewatered and dried forming the paper or paperboard product. The invention further relates to a paper or paperboard produced according to the process and a headbox used in the process.

Abstract: Flame retardant composite materials are provided which include at least one first paper which comprises carbon nanofibers and graphite oxide particles. The composite materials may further include at least one second paper which comprises carbon nanofibers. The composites may further include one or more structural material layers sandwiched between the first and second papers. Occupant structures are also provided with fire and smoke retardant surfaces composed of carbon nanofibers/graphite oxide particles papers at least partially surrounding occupants of the occupant structures.

Abstract: The disclosure provides a method comprising contacting a fibrous polymeric material and a carbon material to form a mixture, contacting the mixture with a liquid to form a slurry, and then forming a layer comprising the slurry. Also disclosed are layers formed from the recited methods, electrodes comprising the layers, and electrical devices comprising the layers and/or electrodes.

Abstract: Tissues are provided as multi-ply tissue products having greater tactile sensation and resiliency in hand. Improved tissues may have a thickened and reduced density middle layer. The tissues may serve as applicators for chemical agents to be released during use of the tissue. A tissue having an improved tactile impression to the consumer, with enhanced resilience and high external bulk is disclosed. In one embodiment, a multi-ply structure having at least three plies is desirable. A middle or intermediate ply is comprised an increased thickness and a greater bulk is employed. In general, the exterior plies of the tissue are smooth and desirable to the consumer.

Abstract: Tissue products are disclosed containing an additive composition. The additive composition, for instance, comprises an aqueous dispersion containing an olefin polymer, an ethylene-carboxylic acid copolymer, or mixtures thereof. The olefin polymer may comprise an interpolymer of ethylene and octene, while the ethylene-carboxylic acid copolymer may comprise ethylene-acrylic acid copolymer. The additive composition may also contain a dispersing agent, such as a fatty acid. The additive composition may be incorporated into the tissue web by being combined with the fibers that are used to form the web. Alternatively, the additive composition may be topically applied to the web after the web has been formed. After the additive composition is applied to the web or otherwise incorporated into the tissue web, the tissue web is embossed. During embossing, the additive composition forms well defined embossments in the web that are water resistant.

Abstract: Multi-ply tissue products are disclosed. The multi-ply tissue products contain tissue webs that have raised areas and depressed areas. The tissue webs may be constructed so as to be relatively non-compressive and may have a resilient three-dimensional structure. During production, in one embodiment, the tissue webs may be produced without being subjected to any substantial compression, such as a calendering process. Although not necessary in all applications, in one embodiment, the tissue webs may be combined such that the depressed areas contact each other to form the multi-ply product. The tissue webs, for instance, may comprise a through-air dried web in which the raised areas and the depressed areas are molded into the web. Tissue products made according to the present invention have enhanced absorption characteristics. For instance, the tissue products can have an interply absorbency of greater than about 3 g/g after 30 seconds.

Abstract: The present invention provides for a tissue product comprising one or more tissue plies and having a total tensile value of less than about 1300 grams per inch, a Bulk300 of greater than about 13.5 cm3/g, and a caliper stability of greater than about 50%. The present invention also provides for a tissue product comprising at least three plies. The tissue product has a total tensile value of less than about 1300 grams per inch, a Bulk300 greater than about 11 cm3/g, and a caliper stability greater than 50%. The present invention further provides for a tissue product comprising as least two plies. The tissue product has a total tensile value of less than about 1300 grams per inch, a Bulk300 of greater than about 7.0 cm3/g, and a caliper stability of greater than about 83%.

Abstract: Tissues are provided as multi-ply tissue products having greater tactile sensation and resiliency in hand. Improved tissues may have a thickened and reduced density middle layer. The tissues may serve as applicators for chemical agents to be released during use of the tissue. A tissue having an improved tactile impression to the consumer, with enhanced resilience and high external bulk is disclosed. In one embodiment, a multi-ply structure having at least three plies is desirable. A middle or intermediate ply is comprised an increased thickness and a greater bulk is employed. In general, the exterior plies of the tissue are smooth and desirable to the consumer.

Abstract: The invention relates to a method of producing a laminate paper product comprising at least two layers, said method comprising (i) providing an aqueous suspension comprising cellulosic fibers (ii) adding to the suspension microfibrillar polysaccharide in an amount to yield from about 0.05 to about 50 wt % based on the weight of the cellulosic fibers (iii) dewatering the obtained suspension and forming a first layer having a density from about 150 to about 500 kg/m3 of said laminate paper product. The invention also relates to a method comprising (i) providing an aqueous suspension comprising cellulosic fibers (ii) adding to the suspension microfibrillar polysaccharide in an amount to yield from about 0.

Abstract: Tissues are provided as multi-ply tissue products having greater tactile sensation and resiliency in hand. Improved tissues may have a thickened and reduced density middle layer. The tissues may serve as applicators for chemical agents to be released during use of the tissue. A tissue having an improved tactile impression to the consumer, with enhanced resilience and high external bulk is disclosed. In one embodiment, a multi-ply structure having at least three plies is desirable. A middle or intermediate ply is comprised an increased thickness and a greater bulk is employed. In general, the exterior plies of the tissue are smooth and desirable to the consumer.

Abstract: The invention provides a three layered reprographic paper having improved strength, stiffness and curl resistance properties, and a method for making same. The paper has a central core layer made largely of cellulose and bulked with a bulking agent such as a diamide salt. A starch-based metered size press coating is pressed on both sides of the core layer, wherein the starch has a high solid content. The coating forms a three layered paper having an I-beam arrangement with high strength outer layers surrounding a low density core.

Abstract: A paper adhesive composition includes a cationic non-crosslinked acidified solution of a polyamidoamine with the repeating units wherein n?1; m=1 or 2; X?m is chloride, bromide, iodide, sulfate, bisulfate, nitrate, oxalate, alkyl carboxylate, aryl carboxylate, hydrogen phosphate, dihydrogen phosphate, alkyl sulfonate, aryl sulfonate, or a combination comprising at least one of the foregoing anions; R1 is a divalent aliphatic, cycloaliphatic, or araliphatic group having from 1 to 24 carbon atoms; R2 is hydrogen or a monovalent aliphatic, cycloaliphatic, or araliphatic group having from 1 to 24 carbon atoms; and R3 is a divalent hydrocarbon radical derived from a dibasic carboxylic acid.

Abstract: The present invention provides a method of manufacturing an article comprising a fiber layer and at least one electronic chip, the fiber layer being formed by depositing fibers on a surface immersed in a dispersion of fiber material. The method includes the following step: Using an elongate flexible support to bring the electronic chip into contact with the fiber layer that is being formed.

Abstract: Method of producing a nonwoven material, includes forming a web of continuous filaments on a forming member (12) and applying a wet- or foam formed fiber dispersion containing natural fibers and/or synthetic staple fibers on top of the continuous filaments. A fibrous web is thus formed containing continuous filaments and natural fibers and/or synthetic staple fibers, this web subsequently being hydroentangled to form a nonwoven material. Moisture is applied to the web of continuous filaments under a low pressure before laying the wet- or foam formed fiber dispersion on the web of continuous filaments, avoiding any substantial bonding between the filaments in the web.

Abstract: The present invention discloses a process and a method providing a high bulk tissue which is both strong and soft. Specifically, it has been discovered that certain low pressure printing technologies may be used to deliver a bonding material to the surface of a high bulk paper web such as an uncreped, through-dried web. The bonding material may be applied to the web either before, during or after the web is softened with a mechanical straining process which will decrease the web bulk by no more than 20% of the initial bulk in order to increase the web softness. The web may be softened by any of a variety of mechanical straining processes such as, for instance, microcreping, microstraining, rush transfer, or other low-compressive softening methods. The cured bonding material on the web may not only increase the bulk of the web when dry and wet, but also increase the wet resiliency and the wet strength of the web.