Multi-zone absorbent substrate and absorbent articles incorporating same

Abstract

Multi-zone nonwoven materials are disclosed that have an excellent combination of absorbency, fluid handling characteristics, and web handling characteristics. The nonwoven materials can be made through a foam forming process. The fiber components selected for each zone of the nonwoven material produces nonwoven materials with a relatively high toughness in combination with a relatively high peak load for improved processability.

Description

[0001] MULTI-ZONE ABSORBENT SUBSTRATE AND ABSORBENT ARTICLES INCORPORATING SAME

[0002] RELATED APPLICATIONS

[0003] The present application is based upon and claims priority to United States Provisional Patent Application Serial No. 63 / 697,091, having a filing date of September 20, 2024, and which is incorporated herein by reference.

[0004] BACKGROUND

[0005] Many different types of nonwoven materials exist that are designed to have different functions. In many embodiments, the nonwoven materials are designed to have liquid handling properties.

[0006] These nonwoven materials can be used in absorbent articles to absorb fluids.

[0007] Absorbent articles, also referred to as personal care products, such as diapers, diaper pants, training pants, adult incontinence products, and feminine care products can include a variety of substrates. For example, absorbent articles can include an absorbent structure, nonwoven materials, and films. These layers are positioned relative to each other so that fluids coming into contact with the absorbent article are quickly drawn into the absorbent structure and contained in order to give the wearer a dry feel.

[0008] Absorbent structures can contain a superabsorbent material. Superabsorbent materials can be configured in the form of particles including fibers and are commonly utilized in substrates for increased absorbent capacity.

[0009] Many current absorbent structures, particularly air-formed or airlaid structures, can bunch and twist during use due to movement and the presence of body fluids, such as menses, when incorporated into an absorbent article, such as a feminine care product. The absorbent structures, for instance, can deform irreversibly and provide a negative consumer experience. In addition, the permeability of the absorbent structure can decrease as the absorbent structure absorbs bodily fluids leading to a potential leakage risk. In addition, many absorbent structures incorporated into absorbent articles, such as feminine care products, can form a large stain area during use, which can also cause a negative consumer experience.

[0010] In view of the above, a need exists for an absorbent structure design that enables the effective transport and retention of fluids. The absorbent structure should also be soft, flexible, and thin. Unfortunately, when actions or components are incorporated into the absorbent structure in order to improve the absorbency characteristics of the product at lower basis weights, the designed absorbent structure is not capable of being incorporated into a commercial manufacturing line. In particular, such structures have a tendency to break or fail during the assembly process. In view of the above, a need currently exists for an absorbent structure that not only has excellent absorbency or fluid handling characteristics, but also has excellent web handling characteristics that allow the absorbent structure to be processed on a commercial machine or line to make absorbent products.

[0011] SUMMARY

[0012] The present disclosure is generally directed to a multi-zone liquid absorbent substrate that has excellent absorbency properties in combination with excellent physical strength properties. The present disclosure is also directed to all different types of absorbent articles incorporating the liquid absorbent substrate, particularly feminine pads. The substrates can be made through a foam forming process. The absorbent substrates made according to the present disclosure are not only multi-zone structures but also contain particular types of materials and components in each zone that leads to a substrate not only having excellent absorbency and fluid handling properties but also is capable of being wound into a roll and then unwound into a commercial manufacturing process without causing breaks or any other disruptions during the formation of absorbent articles.

[0013] In one aspect, for instance, the present disclosure is directed to a nonwoven material comprising an intake zone, a transfer zone, and an absorbent zone positioned between the intake zone and the transfer zone. In accordance with the present disclosure, the nonwoven material displays a toughness of at least 2 in*lbf, such as at least about 5 in*lbf and displays a peak load of at least 2,300 gf, such as at least about 3500 gf. Each of the three zones contain selected fibers so as to provide strength in combination with absorbency and fluid handling properties. The nonwoven material can be a foam formed material and can be constructed such that fibers in the intake zone mix with fibers in the absorbent zone and that fibers in the absorbent zone mix with fibers in the transfer zone.

[0014] The intake zone, in one aspect, can have a basis weight of from about 10 gsm to about 85 gsm, such as from about 40 gsm to about 85 gsm, such as from about 55 gsm to about 80 gsm. The absorbent zone can have a basis weight of from about 60 gsm to about 180 gsm, such as from about 80 gsm to about 155 gsm. The transfer zone, on the other hand, can have a basis weight of from about 10 gsm to about 40 gsm, such as from about 10 gsm to about 25 gsm, such as from about 20 gsm to about 30 gsm, such as from about 12 gsm to about 18 gsm. The above basis weights, however, represent specific embodiments and nonwoven materials can be made in accordance with the present disclosure having a thinner structure with less basis weight or can have a greater basis weight. In general, the total basis weight of the nonwoven material can be from about 100 gsm to about 800 gsm, such as from about 100 gsm to about 500 gsm, such as from about 130 gsm to about 300 gsm, such as from about 140 gsm to about 275 gsm, such as from about 140 gsm to about 200 gsm. In one aspect, the intake zone and the transfer zone can have a similar fiber composition and / or similar basis weight. For instance, the intake zone and the transfer zone can both contain binder fibers, synthetic polymer fibers, and crosslinked pulp fibers. In one aspect, for instance, the intake zone and the transfer zone can contain binder fibers in an amount from about 10% by weight to about 40% by weight, such as from about 10% by weight to about 30% by weight, such as from about 15% by weight to about 25% by weight, can contain synthetic polymer fibers in an amount from about 40% by weight to about 60% by weight, such as in an amount from about 45% by weight to about 55% by weight, and can contain crosslinked pulp fibers in an amount from about 20% by weight to about 40% by weight, such as in an amount from about 25% by weight to about 35% by weight. In one aspect, the basis weight of the intake zone can be within about 5 gsm of the basis weight of the transfer zone.

[0015] Matching the fiber composition of the intake zone and the transfer zone has been found to unexpectedly and dramatically improve the toughness and peak load of the overall nonwoven material. For example, nonwoven materials made according to the present disclosure can display a toughness of greater than about 2.5 in*lbf, such as greater than about 3 in*lbf, such as greater than about 3.5 in*lbf, such as greater than about 4 in*lbf, such as greater than about 4.5 in*lbf, such as greater than about 5 in*lbf, and less than about 15 in*lbf. The nonwoven material can display a peak load of greater than about 2,500 gf, such as greater than about 3,000 gf, such as greater than about 3,500 gf, and less than about 5,000 gf. Even when displaying the above strength properties, the nonwoven material of the present disclosure can also display an elongation of greater than about 5%, such as greater than about 7%, such as greater than about 10%.

[0016] The absorbent article or absorbent structure made in accordance with the present disclosure can also display excellent fluid handling properties in combination with being extremely flexible and thin. For example, the absorbent article or absorbent structure, when tested according to the Intake Test, can display a second intake time of less than about 140 seconds, such as less than about 120 seconds, such as less than about 100 seconds, such as less than about 90 seconds, such as less than about 80 seconds, such as less than about 75 seconds, and greater than about 25 seconds; and can display a rewet of less than about 3.5 g, such as less than about 3 g, such as less than about 2.8 g, such as less than about 2.5 g, such as less than about 2.3 g, and greater than about 0.5 g.

[0017] The absorbent article or absorbent structure can display a retention capacity of greater than about 25 grams, such as greater than about 27 grams, such as greater than about 30 grams, such as greater than about 33 grams, and less than about 80 grams.

[0018] When tested according to the Horizontal Side Compression Test, the absorbent article can display an energy after three cycles of less than about 1000 gfcm, such as less than about 700 gfcm, such as less than about 650 gfcrn, such as less than about 600 gfcrn, and greater than about 200 gf crn; and can display a width recovery of greater than about 70%, such as greater than about 73%, such as greater than about 75%, such as greater than about 76%, and less than about 99%.

[0019] The absorbent zone, in one aspect, contains binder fibers, crosslinked pulp fibers, bleached chemithermomechanical pulp fibers, and a superabsorbent material. The absorbent zone can contain the superabsorbent material in an amount greater than about 20% by weight, such as in an amount greater than about 25% by weight, such as in an amount greater than about 28% by weight. The absorbent zone can contain the superabsorbent material in an amount less than about 40% by weight, such as in an amount less than about 38% by weight, such as in an amount less than about 35% by weight.

[0020] In one aspect, the absorbent zone can contain binder fibers in an amount from about 10% by weight to about 40% by weight, such as from about 10% by weight to about 30% by weight based upon the total amount of fibers present in the zone. The absorbent zone can contain crosslinked pulp fibers in an amount from about 15% by weight to about 35% by weight based upon the total amount of fibers contained in the zone and can contain bleached chemithermomechanical pulp fibers in an amount from about 45% by weight to about 65% by weight based upon the total fibers present in the zone. Although bleached chemithermomechanical pulp fibers can be present in the absorbent zone, in one aspect, bleached chemithermomechanical pulp fibers are not present or only contained in relatively low amounts in the intake zone and transfer zone. For example, the intake zone and the transfer zone can contain bleached chemithermomechanical pulp fibers in an amount less than about 3% by weight, such as in an amount less than about 2% by weight, such as in an amount less than about 1 % by weight, such as in an amount less than about 0.5% by weight.

[0021] The absorbent zone can have a basis weight of greater than about 60 gsm, such as greater than about 65 gsm, such as greater than about 70 gsm, such as greater than about 75 gsm, and less than about 180 gsm, such as less than about 155 gsm in one embodiment. The basis weight ratio between the intake zone and the absorbent zone can be from about 10:90 to about 45:55, such as from about 35:65 to about 45:55. The basis weight ratio between the transfer zone and the absorbent zone can be from about 1 :20 to about 1 :1 .5.

[0022] In another aspect, the nonwoven material of the present disclosure comprises a multi-zone structure having an intake zone. The intake zone comprises from about 10% by weight to about 40% by weight binder fibers, comprises from about 40% by weight to about 60% by weight synthetic polymer fibers, and contains from about 20% by weight to about 40% by weight crosslinked pulp. The intake zone can be positioned adjacent to an absorbent zone. The absorbent zone can comprise a plurality of fibers including from about 10% by weight to about 30% by weight binder fibers based on the total amount of fibers present in the zone, can contain from about 15% by weight to about 35% by weight crosslinked pulp fibers based upon the total amount of fibers contained in the zone, and can contain from about 45% by weight to about 65% by weight bleached chemithermomechanical pulp fibers based upon the total amount of fibers contained in the zone. The absorbent zone can further comprise a superabsorbent material present in the zone in an amount from about 20% by weight to about 40% by weight. The absorbent zone can be positioned adjacent to a transfer zone such that the absorbent zone is positioned between the intake zone and the transfer zone. The transfer zone can contain from about 10% by weight to about 40% by weight binder fibers, can contain from about 40% by weight to about 60% by weight synthetic polymer fibers, and can contain from about 20% by weight to about 40% by weight crosslinked pulp fibers.

[0023] Each zone can also contain various other components and ingredients. For instance, in one aspect, at least one of the zones contains a wet strength agent. For instance, at least two of the zones or all three of the zones can contain the wet strength agent. The wet strength agent can be present in the zones in an amount of less than 1% by weight, such as in an amount less than about 0.5% by weight, such as in an amount less than about 0.1 % by weight.

[0024] The present disclosure is also directed to absorbent articles incorporating the multi-zone substrate as described above. The absorbent article, for instance, can include a fluid permeable liner, an outer cover, and an absorbent core comprising the nonwoven material of the present disclosure positioned between the liner and the outer cover. In one aspect, the absorbent article can comprise a diaper or child’s pant, including a training pant. Alternatively, the absorbent article can comprise an adult incontinence product. In one particular embodiment, the absorbent article can comprise a feminine care product, such as a feminine care pad.

[0025] Other features and aspects of the present disclosure are discussed in greater detail below. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] A full and enabling disclosure of the present disclosure is set forth more particularly in the remainder of the specification, including reference to the accompanying figures, in which:

[0027] FIG. 1 is a side plan view of an exemplary multi-zone absorbent material including three zones according to one embodiment of the present disclosure;

[0028] FIG. 2 is a process schematic of an exemplary apparatus and associated method for forming a multi-zone absorbent material;

[0029] FIG. 3 is a detailed view of the headbox, headbox inputs, and resultant slurry from the headbox of FIG. 2;

[0030] FIG. 4 is a side plan view of an alternative apparatus and associated method that can be used for forming a multi-zone absorbent material; FIG. 5 is a plan view of one embodiment of an absorbent article made in accordance with the present disclosure;

[0031] FIG. 6 is a graphical representation of some of the results obtained in the Examples below;

[0032] FIG. 7 is a graphical representation of some of the results obtained in the Examples below;

[0033] FIG. 8 is a graphical representation of some of the results obtained in the Examples below;

[0034] FIG. 9 is a graphical representation of some of the results obtained in the Examples below;

[0035] FIG. 10 is a graphical representation of some of the results obtained in the Examples below;

[0036] FIG. 11 is a graphical representation of some of the results obtained in the Examples below; and

[0037] FIG. 12 is a graphical representation of some of the results obtained in the Examples below;

[0038] Repeat use of reference characters in the present specification and drawings is intended to represent the same or analogous features or elements of the present invention.

[0039] DEFINITIONS

[0040] As used herein, the term “foam formed product” means a product formed from a suspension including a mixture of a solid, a liquid, and dispersed gas bubbles.

[0041] As used herein, the term “foam forming process” means a process for manufacturing a product involving a suspension including a mixture of a solid, a liquid, and dispersed gas bubbles.

[0042] As used herein, the term “foaming fluid” means any one or more known fluids compatible with the other components in the foam forming process. Suitable foaming fluids include, but are not limited to, water.

[0043] As used herein, the term “foam half life” means the time elapsed until the half of the initial frothed foam mass reverts to liquid water.

[0044] As used herein, the term “zone” refers to a structure that provides an area of a substrate in a height direction of the substrate that is comprised of similar components and structure. There may be some mixing of fiber between adjacent zones.

[0045] As used herein, the term "nonwoven web" means a web having a structure of individual fibers or threads which are interlaid, but not in an identifiable manner as in a knitted web.

[0046] As used herein, unless expressly indicated otherwise, when used in relation to material compositions the terms "percent", “%”, "weight percent", or "percent by weight" each refer to the quantity by weight of a component as a percentage of the total except as whether expressly noted otherwise.

[0047] The term “absorbent article" refers herein to an article intended and / or adapted to be placed against or in proximity to the body (i.e., contiguous with the body) of the wearer to absorb and contain various liquid, solid, and semi-solid exudates discharged from the body. Examples include, but are not limited to, diapers, diaper pants, training pants, youth pants, swim pants, feminine hygiene products, including, but not limited to, menstrual pads or pants, incontinence products, medical garments, surgical pads and bandages, and so forth.

[0048] The term "superabsorbent material" as used herein refers to water-swellable, water-insoluble organic or inorganic materials including superabsorbent polymers and superabsorbent polymer compositions capable, under the most favorable conditions, of absorbing at least about 10 times their weight, or at least about 15 times their weight, or at least about 25 times their weight in an aqueous solution containing 0.9 weight percent sodium chloride.

[0049] The term "machine direction" as used herein refers to the direction of travel of the forming surface onto which fibers are deposited during formation of a nonwoven web.

[0050] The term "cross-machine direction" as used herein refers to the direction which is perpendicular to both the machine direction and the height direction defined above.

[0051] The term "pulp" as used herein refers to fibers from natural sources such as woody and non- woody plants. Woody plants include, for example, deciduous and coniferous trees. Non-woody plants include, for example, cotton, flax, esparto grass, milkweed, straw, jute, hemp, and bagasse. Pulp fibers can include hardwood fibers, softwood fibers, and mixtures thereof.

[0052] The term "average fiber length" as used herein refers to an average length of fibers, fiber bundles and / or fiber-like materials determined by measurement utilizing microscopic techniques. A sample of at least 20 randomly selected fibers is separated from a liquid suspension of fibers. The fibers are set up on a microscope slide prepared to suspend the fibers in water. A tinting dye is added to the suspended fibers to color cellulose-containing fibers so they may be distinguished or separated from synthetic fibers. The slide is placed under a Fisher Stereomaster II Microscope— S19642 / S19643 Series. Measurements of 20 fibers in the sample are made at 20X linear magnification utilizing a 0-20 mils scale and an average length, minimum and maximum length, and a deviation or coefficient of variation are calculated. In some cases, the average fiber length will be calculated as a weighted average length of fibers (e.g . , fibers, fiber bundles, fiber-like materials) determined by equipment such as, for example, a Kajaani fiber analyzer Model No. FS-200, available from Kajaani Oy Electronics, Kajaani, Finland. According to a standard test procedure, a sample is treated with a macerating liquid to ensure that no fiber bundles or shives are present. Each sample is disintegrated into hot water and diluted to an approximately 0.001% suspension. Individual test samples are drawn in approximately 50 to 100 ml portions from the dilute suspension when tested using the standard Kajaani fiber analysis test procedure. The weighted average fiber length may be an arithmetic average, a length weighted average or a weight weighted average and may be expressed by the following equation: where k=maximum fiber length

[0053] XFfiber length npnumber of fibers having length xi n=total number of fibers measured.

[0054] One characteristic of the average fiber length data measured by the Kajaani fiber analyzer is that it does not discriminate between different types of fibers. Thus, the average length represents an average based on lengths of all different types, if any, of fibers in the sample.

[0055] As used herein the term "staple fibers" means discontinuous fibers made from synthetic polymers or regenerated cellulose, such as polypropylene, polyester, post consumer recycle (PCR) fibers, polyester, nylon, viscose, rayon, and the like, and those not hydrophilic may be treated to be hydrophilic. Staple fibers may be cut fibers or the like. Staple fibers can have cross-sections that are round, bicomponent, multicomponent, shaped, hollow, or the like.

[0056] The term “plied” or “bonded” or “coupled” refers herein to the joining, adhering, connecting, attaching, or the like, of two elements. Two elements will be considered plied, bonded or coupled together when they are joined, adhered, connected, attached, or the like, directly to one another or indirectly to one another, such as when each is directly bonded to intermediate elements. The plying, bonding or coupling of one element to another can occur via continuous or intermittent bonds.

[0057] As used herein, “binder fibers” are fibers that can bond to other fibers in a substrate using chemical, mechanical, or thermal means. The binder fibers may comprise thermally bondable fibers that, when heated, form thermal bonds with other fibers at their point of intersection. In one aspect, the binder fibers include a surface polymer having a lower melting temperature. For instance, the binder fibers can be made from a polymer, such as a polyolefin, having a melting temperature of less than 200°C, such as less than 180°C, such as less than 160°C, such as less than 140°C, such as less than 120°C, such as less than 100°C, and greater than 80°C, such as greater than 90°C. In one aspect, the binder fibers comprise conjugate fibers, such as bicomponent fibers. The conjugate fibers can have a core and sheath structure, including a core polymer surrounded by a sheath polymer. The core polymer can have a higher melting temperature than the sheath polymer. The core polymer can be selected for its strength and high melting point and the sheath polymer can be made from a polymer selected for its lower melting temperature. The core polymer, for instance, can have a melting temperature higher than the sheath polymer. In this manner, the sheath polymer, when subjected to heat, melts and bonds to other fibers within the web at intersecting points. The core polymer, however, allows the bicomponent binder fiber to retain its shape and provide strength.

[0058] As used herein, “synthetic polymer fibers” refers to fibers made from polymers that are not binder fibers. Synthetic polymer fibers can include polyester fibers, such as fibers made from a polyethylene terephthalate polymer. Other polymer synthetic fibers include polyolefin fibers, such as polyethylene fibers, polypropylene fibers, and fibers made from copolymers of the above.

[0059] As used herein, the tensile properties of nonwoven materials including “toughness” and “peak load” were determined in substantial accordance with ASTM Standard D-5034.

[0060] Specifically, a nonwoven web sample was cut or otherwise provided with size dimensions that measured 25 millimeters (width)*127 millimeters (length). A constant-rate-of-extension type of tensile tester was employed. The tensile testing system was a Sintech Tensile Tester, which is available from Sintech Corp, of Cary, N.C. The tensile tester was equipped with TESTWORKS 4.08B software from MTS Corporation to support the testing. An appropriate load cell was selected so that the tested value fell within the range of 10-90% of the full scale load. The sample was held between grips having a front and back face measuring 25.4 millimetersx76 millimeters. The grip faces were rubberized, and the longer dimension of the grip was perpendicular to the direction of pull. The grip pressure was pneumatically maintained at a pressure of 40 pounds per square inch. The tensile test was run at a 300-millimeter per minute rate with a gauge length of 10.16 centimeters and a break sensitivity of 40%.

[0061] Five samples were tested by applying the test load along the machine-direction. The peak load, peak elongation (i.e. % strain at peak load) and the toughness (energy to peak) were measured. The results of the five samples were averaged.

[0062] As used herein, the Intake Test Method including rewet is as follows. The test is described in US Patent Application 2014 / 0121625, which is incorporated herein by reference, with reference to Figures 46 and 46A. US Patent Application 2014 / 0121625 also describes the preparation of a menses stimulant as may be used in this test. The prepared absorbent composites are laid flat on the testing surface The top of the absorbent composite is then insulted with a first 2 mL gush of room temperature menses simulant (24 mL / min), followed by a 2 minute, 55 second pause, followed by a 3 mL trickle (0.3 mL / min), and then a second 2 mL gush (24 mL / min). As shown in Figures 46 and 46A of US Patent Application 2014 / 0121625 the menses simulant is administered through a cannula in a rate block that is placed at the center crotch of the test product. The rate block is made of a nonelectrostatic material called Ertalyte. This material allows simulant to pass along its surface without attracting it. The opening is oval shaped and measures 60 mm long (L3)x 13 mm wide (W3) with its ends consisting of 4-mm diameter half circles. As shown in FIG. 46 and FIG. 46A, the cannula is inserted through a small center hole offset in the top of the rate block to allow the cannula to be at an angle with respect to the oval opening and to allow the fluid to be applied through the center of the rate block oval opening.

[0063] The first and second Intake values are measured with a stopwatch during the first and second 2 mL gush, respectively. The stopwatch is started when the gush starts and is stopped when the fluid from the gush is completely absorbed by the absorbent composite. Rewet values are determined after complete penetration of the second 2 mL gush. To measure rewet values, two pieces of blotting paper (Verigood grade, white, 300 g / m2, 48.26 by 60.96 cm stock, 250 sheets per ream, Georgia-Pacific Corp, part number 411-01-12, or equivalent) are placed to cover the insulted absorbent composite. A foot that covers the absorbent composite is lowered against the blotter paper to create a pressure load of 1 .0 psi for 3 minutes and the amount of fluid transferred to the blotting paper is determined gravimetrically. The pressure used in this test has been shown to correlate well with the pressure applied to feminine hygiene pads during use.

[0064] As used herein, thickness measurements utilize a standard bulk tester with clear, cast acrylic foot that provides 0.05psi.

[0065] As used herein, the Horizontal Side Compression Test is performed as follows with reference to Figures 7A and 7B of WO 2023 / 164126 which is incorporated herein by reference. During the test, the absorbent material is compressed horizontally. The test is designed to compress an absorbent product in the crotch area to measure the resiliency, flexibility or stiffness, and width recovery of the crotch area of the product.

[0066] The test protocol has 10 compression cycles of a dry product followed by 10 compression cycles of wet product. A relevant test fluid, saline or defibrinated swine blood, is applied to the product following the dry compression cycles. This test is performed with the product in a horizontal position to represent the typical user position of active wear. Additionally, a horizontal placement facilitates the ability to insult the products with the test fluids without needing to remove the test sample from the apparatus.

[0067] The product may be tested with or without flaps and / or with or without wings. Test outputs include energy, resiliency, and width recovery.

[0068] A CRE (Constant Rate of Extension) type of tensile tester with data acquisition unit and data acquisition program capable of collecting data such as Instron 3343 system with Bluehill program or MTS Insight 1 EL system with TestWorks 4.0 is used during the test. The product being tested is oriented horizontally in the test jaws.

[0069] Unless otherwise indicated, defibrinated swine blood @ 35% red blood cells is used which is available from Cocalico Biologicals, Inc. The product should be conditioned for 4 hours in TAPPI conditions prior to testing. The center point and insult location of each product should be marked. For incontinence and menstrual pads, measure the length of the entire product and divide by 2. This value will represent the center point. Put a vertical mark at the center point. The center point will be the insult location.

[0070] The Test is conducted by warming up the tensile tester according to the manufacturer's manual. Next, verify the appropriate load cell is in the tensile tester, which should be selected from either a 50 Newton or 100 Newton maximum, depending on the peak force value of the sample being tested, such that the majority of peak load values fall between 5-95% of the load cell's full scale value. For purposes of the samples tested herein, a 100 Newton load cell is used. In this test, both edges of the absorbent material are clamped between top and bottom grips of the tensile tester with the center of the sample aligned with the center of the grips and the sample centered between the grips. The computer is turned on and the software menu selection is followed. The load cell for the tensile tester is calibrated according to the manufacturer's instructions. The test conditions are as follows.

[0071] Cross Head Speed 508 + / - 5mm / min

[0072] Gauge Length 90mm (initial compression plate separation distance)

[0073] End Compression Distance 30mm

[0074] Load Unit Newton

[0075] Full Scale Load 100 Newton (use an appropriate load cell for the product being tested so that the test value falls between 5% and 95% of the full-scale load)

[0076] Sample materials can be placed in product form by using the absorbent product sample.

[0077] Ensure the lanyard thread is in and remains in the wheel guides, one in the front and two wheel guides in the back of the tester (see Figures 7A and 7B from WO 2023 / 164126). A piece of masking tape can be placed close to one of the back wheels of the tester without touching the lanyard to prevent the lanyard moving out of the wheel when the crosshead returns to its start position. Two hanging weights are attached to the wheel guide at the far back of the testing unit. Orient the weights up-side down to shorten the hook length such that the weights do not touch the frame.

[0078] With the lanyard attached to a hook below the load cell, adjust the crosshead so the resultant force exerted by the lanyard is less than 0.5 grams. Measure and then record the initial width of the specimen in the mid-crotch area. Then, zero the crosshead channel and start the test run.

[0079] At the end of the 10thcycle in the dry condition, the test will pause with fixture open at the initial plate compression separation distance. Add a single insult of test fluid at the insult location (5 mL). Run 10 more cycles. At the conclusion of all cycles, measure and record the final width of the specimen in the midcrotch area. A data report is generated that provides the cycle 1 energy, cycle 10 energy and cycle 20 energy (gf*cm). The width recovery % is measured as final width at end of all cycles divided by the initial width, multiplied by 100.

[0080] As used herein, the Retention Capacity Test is as follows. This test is used to determine the amount of defibri n ated swine blood testing fluid absorbed and retained by an absorbent product. The weight in grams of defibrinated blood absorbed by the product is recorded. Defibrinated Swine Blood with Gentamicin, 35% Hematocrit (% red blood cells) available from Cocalico Biologicals is used in the test. The products to be tested are weighed prior to testing and placed on mesh screens into saturation containers so the products are body-side up. The containers are placed on a rocker and an adequate amount of defibrinated swine blood is added so that it just covers the product. More swine blood may be added throughout the soaking time, if necessary, to ensure the pad is fully covered. The rocker is turned on so that it rocks very slowly and gently, and the fluid moves freely to both ends of the container. The product is allowed to saturate with the blood for 30 minutes followed by removal from the saturation container and excess fluid allowed to drip for five minutes. The product is then transferred to a vacuum box and placed on a screen with the body-side facing the screen and a vacuum of 0.5 psi is applied and the product held for 5 minutes. Excess free fluid is drained from the product and the product is then weighed. The difference in weight between the weight of the product after the test and the dry product before the test is recorded as retention capacity of the product.

[0081] DETAILED DESCRIPTION

[0082] It is to be understood by one of ordinary skill in the art that the present discussion is a description of exemplary embodiments only and is not intended as limiting the broader aspects of the present disclosure.

[0083] The present disclosure is directed to methods and systems that can produce nonwoven substrates. While the present disclosure provides examples of substrates manufactured through foam-forming, it is contemplated that the methods and apparatuses described herein may be utilized to benefit wet-laid and / or air-laid manufacturing processes.

[0084] Each example is provided by way of explanation and is not meant as a limitation. For example, features illustrated or described as part of one embodiment or figure can be used on another embodiment or figure to yield yet another embodiment. It is intended that the present disclosure include such modifications and variations.

[0085] When introducing elements of the present disclosure or the preferred embodiment(s) thereof, the articles “a”, “an", “the” and “said” are intended to mean that there are one or more of the elements. The terms "comprising”, “including” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. As used herein, the terminology of “first,” “second,” “third”, etc. does not designate a specified order, but is used as a means to differentiate between different occurrences when referring to various features in the present disclosure. Many modifications and variations of the present disclosure can be made without departing from the spirit and scope thereof. Therefore, the exemplary embodiments described herein should not be used to limit the scope of the invention.

[0086] In general, the present disclosure is directed to nonwoven materials comprising multi-zone substrates, particularly multi-zone substrates having excellent fluid handling properties including the ability to absorb large amounts of fluids. In one aspect, the multi-zone substrate can be made using a foam forming process which has been found to produce various advantages and benefits.

[0087] Multi-zone substrates made according to the present disclosure not only have good fluid absorbency characteristics, but also have excellent strength properties. In this manner, the substrates are easy to handle and manipulate. For instance, the multi-zone substrates made according to the present disclosure can be formed and then wound into a roll for later feeding to a process for producing absorbent articles. More particularly, nonwoven materials made according to the present disclosure include a multi-zone structure having particular components contained in each zone in order to produce an overall product having a relatively high toughness and peak load. It was discovered that increasing toughness and peak load dramatically improved the runnability of the nonwoven material in a commercial processing line.

[0088] Nonwoven materials made according to the present disclosure generally contain at least three zones. The nonwoven materials, for instance, can include an intake zone that is designed to be placed adjacent to the wearer, an absorbent zone for absorbing and retaining bodily fluids, and a transfer zone. The transfer zone can form a bottom exterior zone and may be designed to prevent superabsorbent material from escaping the nonwoven material from the absorbent zone. In one aspect, the intake zone and the transfer zone are constructed from the same fibers in relatively the same amounts which has been found to unexpectedly increase toughness and peak load.

[0089] In addition to having excellent strength properties, the nonwoven material made according to the present disclosure also has excellent absorbency and fluid handling properties. In particular, the nonwoven material can have increased permeability in combination with increased inter-fiber bonding at fiber crossover points which increases the ability to draw in bodily fluids, such as menses, from a bodyside liner of an absorbent article and to transfer the bodily fluids to the absorbent zone for maintaining a dry environment for the wearer. The blend of fibers used to make the different zones has also been found to provide excellent resiliency thereby creating z-directional resilience which in turn increases the permeability and decreases the x and y distribution which can help decrease the area and intensity of any stain developed by the product. The nonwoven material also can be produced with relatively high void volume which promotes bodily fluid intake and provides additional capacity for insult. More particularly, the combination of a capillary gradient and a wettability gradient helps pull fluids into the absorbent zone in an efficient manner. All of these benefits can be obtained, in one embodiment, at a reduced mass. For instance, the transfer zone can have a relatively low basis weight, such as less than about 85 gsm, such as less than about 80 gsm. It is believed that one or more of these benefits are enhanced through a foam forming process.

[0090] As described above, by selecting the materials contained in each zone of the multi-zone substrate and by controlling the amount of the components contained in each zone, multi-zone substrates made according to the present disclosure can have an excellent balance of absorbency and strength. For example, nonwoven materials made according to the present disclosure can display a toughness of at least 2 in*lbf. The toughness, for instance, can be greater than about 2.5 in*lbf, such as greater than about 3 in*lbf, such as greater than about 3.5 in*lbf, such as greater than about 4 in*lbf, such as greater than about 4.5 in*lbf, such as greater than about 5 in*lbf. The toughness is generally less than about 15 in*lbf.

[0091] The nonwoven materials of the present disclosure can have enhanced toughness in conjunction with excellent peak load properties. For instance, the nonwoven material can display a peak load of greater than about 2300 gf, such as greater than about 2400 gf, such as greater than about 2500 gf, such as greater than about 2600 gf, such as greater than about 2700 gf, such as greater than about 2800 gf. The peak load is generally less than about 8,000 gf, such as less than about 15,000 gf. Nonwoven materials made according to the present disclosure can be processed at very high speeds without experiencing any web breaks. For instance, the materials can be processed at speeds greater than about 500 ft / min, such as greater than about 1 ,000 ft / min.

[0092] In one aspect, the absorbent substrate incorporated into products of the present disclosure are relatively thin while having excellent absorbency and strength properties. For instance, the absorbent substrate or absorbent article can have a thickness of less than about 8 mm, such as less than about 6 mm, such as less than about 5 mm, such as less than about 4 mm, such as less than about 3.5 mm, such as less than about 3 mm, such as less than about 2.8 mm, such as less than about 2.3 mm, such as less than about 2 mm, and greater than about 0.5 mm, such as greater than about 1 mm.

[0093] Even at the above thicknesses, when tested according to the Intake Test, the absorbent substrate or article can display a second intake time of less than about 140 seconds, such as less than about 120 seconds, such as less than about 100 seconds, such as less than about 90 seconds, such as less than about 80 seconds, such as less than about 75 seconds, and greater than about 25 seconds; and can display a rewet of less than about 3.5 g, such as less than about 3 g, such as less than about 2.8 g, such as less than about 2.5 g, such as less than about 2.3 g, and greater than about 0.5 g.

[0094] The absorbent article or absorbent structure can display a retention capacity of greater than about 25 grams, such as greater than about 27 grams, such as greater than about 30 grams, such as greater than about 33 grams, and less than about 80 grams.

[0095] In addition to having excellent fluid handling properties, the absorbent article can be very flexible. When tested according to the Horizontal Side Compression Test, the absorbent article can display an energy after three cycles of less than about 1000 gfcm, such as less than about 700 gfcm, such as less than about 650 gfcm, such as less than about 600 gfcm, and greater than about 200 gfcm; and can display a width recovery of greater than about 70%, such as greater than about 73%, such as greater than about 75%, such as greater than about 76%, and less than about 99%.

[0096] Referring to FIG. 1 , for exemplary purposes, one example of a nonwoven material 10 made in accordance with the present disclosure is shown. FIG. 1 illustrates a three-zone embodiment. In particular, the nonwoven material 10 includes an intake zone 12 positioned adjacent to an absorbent zone 13. An interface 15 is located between the intake zone 12 and the absorbent zone 13. The nonwoven material 10 further includes a transfer zone 17. As shown, the absorbent zone 13 is positioned between the intake zone 12 and the transfer zone 17. An interface 19 is located between the absorbent zone 13 and the transfer zone 17. In one aspect, some of the materials or fibers contained in the intake zone 12 can mix with some of the materials or fibers contained in the absorbent zone 13 along the interface 15. Similarly, some of the fibers or materials contained in the absorbent zone 13 can mix with some of the fibers or materials contained in the transfer zone 17 at the interface 19. The interfaces 15 and 19 can provide the benefit of having some fiber distribution between adjacent zones for providing enhanced stabilization properties.

[0097] The intake zone 12 and the transfer zone 17 can serve as containment zones for the absorbent zone 13. In particular, the intake zone 12 and the transfer zone 17 can be configured to be relatively thin and have a low basis weight while providing enough strength for handling and converting and while adding minimal stiffness. The absorbent zone 13 can contain a superabsorbent material that is prevented from contacting a user or wearer due to the presence of the intake zone 12 and the transfer zone 17. In this manner, the intake zone 12 and the transfer zone 17 can improve the feel and comfort of the nonwoven material 10 by reducing any gritty feel that may occur when there is contact with superabsorbent materials. The intake zone 12 and the transfer zone 17 can also prevent superabsorbent materials from escaping making the nonwoven material easier to handle and process. In this manner, the absorbent zone 13 can contain relatively high amounts of superabsorbent materials without any drawbacks.

[0098] The intake zone 12 can be a top zone that is configured to face a wearer when the nonwoven material 10 is incorporated into an absorbent article. In one aspect, the intake zone 12 can be designed to quickly allow fluids including menses to be absorbed by the absorbent zone 13. For example, in one embodiment, the intake zone 12 can be a low density zone with high permeability characteristics.

[0099] In one aspect, the intake zone 12 can contain a mixture of binder fibers, synthetic polymer fibers, and crosslinked pulp fibers.

[0100] Binder fibers that can be incorporated into the intake zone 12 include mono-component fibers and multi-component fibers. The multi-component fibers, for instance, can include a core polymer surrounded by a sheath polymer. The sheath polymer can be comprised of a low melting thermoplastic polymer such as polyethylene. In one aspect, the binder fibers comprise bicomponent fibers containing a core polymer made from a polyester polymer or a polypropylene polymer. For example, the core polymer can be a polyethylene terephthalate polymer. The sheath polymer, on the other hand, can have a lower melting temperature than the core polymer and can comprise a polyolefin, such as polyethylene.

[0101] The binder fibers can have any suitable size and length. For instance, the binder fibers can have a length of between about 0.5 mm to about 50 mm, such as from about 0.75 mm to about 30 mm. In one aspect, the binder fibers have a length of from about 1 mm to about 25 mm. The binder fibers can have a size of from about 0.1 denier to about 5 denier. For instance, the size can be less than about 3 denier, such as less than about 2 denier, and greater than about 0.7 denier, such as greater than about 1 denier.

[0102] In one aspect, the intake zone 12 can contain binder fibers in an amount from about 10% by weight to about 40% by weight, including all increments of 1% therebetween. For example, the intake zone 12 can contain binder fibers in an amount greater than about 13% by weight, such as in an amount greater than about 15% by weight, such as in an amount greater than about 18% by weight The binder fibers can generally be present in an amount less than about 30% by weight, such as less than about 28% by weight, such as in an amount less than about 25% by weight, such as in an amount less than about 23% by weight.

[0103] In addition to containing binder fibers, the intake zone 12 can contain various other materials, including other fibers. In one aspect, for instance, the intake zone 12 can contain synthetic polymer fibers. The synthetic polymer fibers, for instance, can be made from a polymer material and can be non-absorbent. As described above, in one aspect, the nonwoven material 10 can be produced using a foam forming process in which the fibers and other materials are suspended in a foam and then deposited onto a forming surface to form the multi-zone structure. Of advantage, the foam forming process can accommodate all different types of materials and fibers including polymer synthetic fibers. For example, the polymer synthetic fibers can have a bending stiffness that is substantially unimpacted by the presence of the forming fluid.

[0104] Examples of synthetic polymer fibers include polyolefin, polyester (PET), polyamide, polylactic acid, or other fiber forming polymers. Polyolefin fibers, such as polyethylene (PE) and polypropylene (PP), and polyethylene terephthalate fibers are particularly well suited for use in the present disclosure. In some embodiments, non-absorbent fibers can be recycled fibers, compostable fibers, and / or marine degradable fibers. In this regard, due to its very low levels of absorbency to water, water resistant fibers do not experience a significant change in bending stiffness upon contacting an aqueous fluid and therefore are capable of maintaining an open composite structure upon wetting. The fiber diameter of a fiber can contribute to enhanced bending stiffness. For example, a PET fiber has a higher bending stiffness than a polyolefin fiber whether in dry or wet states. The higher the fiber denier, the higher the bending stiffness a fiber exhibits. Water resistant fibers desirably have a water retention value (WRV) less than about 1 and still more desirably between about 0 and about 0.5. In certain aspects, it is desirable that the fibers, or at least a portion thereof, include non-absorbent fibers.

[0105] The synthetic and / or water resistant fibers can have fiber length greater than about 0 2 mm including, for example, having an average fiber size between about 0.5 mm and about 50 mm or between about 0.75 and about 30 mm or even between about 1 mm and about 25 mm.

[0106] In some embodiments, the synthetic and / or water resistant fibers can have a crimped structure to enhance bulk generation capability of the foam formed fibrous substrate. For example, a PET crimped staple fiber may be able to generate a higher caliper (or result in a low sheet density) in comparison to a PET straight staple fiber with the same fiber diameter and fiber length.

[0107] For exemplary purposes, the intake zone 12 can contain synthetic polymer fibers generally in an amount from about 40% by weight to about 60% by weight, including all increments of 1 % by weight therebetween. For instance, the polymer synthetic fibers can be present in the intake zone 12 in an amount greater than about 42% by weight, such as in an amount greater than about 45% by weight, such as in an amount greater than about 48% by weight. The polymer synthetic fibers can be present in the intake zone 12 in an amount less than about 58% by weight, such as in an amount less than about 55% by weight, such as in an amount less than about 53% by weight.

[0108] In addition to or instead of polymer synthetic fibers, the intake zone 12 can also contain cellulose fibers. Various different types of cellulose fibers can be incorporated into the intake zone 12. In one aspect, for instance, the intake zone 12 contains crosslinked pulp fibers. Crosslinked cellulosic or pulp fibers can provide increased bulk and resiliency as well as improved softness. For exemplary purposes only, the intake zone 12 can contain crosslinked cellulose fibers generally in an amount from about 20% by weight to about 40% by weight, including all increments of 1% by weight therebetween. For instance, the crosslinked cellulose fibers can be present in the intake zone 12 in an amount greater than about 22% by weight, such as in an amount greater than about 25% by weight, such as in an amount greater than about 27% by weight. The cellulose fibers can be present in the intake zone 12 in an amount less than about 38% by weight, such as in an amount less than about 35% by weight, such as in an amount less than about 33% by weight.

[0109] In one aspect, the intake zone 12 can have a relatively low basis weight in comparison to many past airlaid products. For instance, the basis weight of the intake zone 12 can be less than about 85 gsm, such as less than about 80 gsm, such as less than about 75 gsm, such as less than about 70 gsm, and greater than about 10 gsm, such as greater than about 20 gsm, such as greater than about 30 gsm, such as greater than about 45 gsm, such as greater than about 50 gsm, such as greater than about 55 gsm, such as greater than about 60 gsm.

[0110] The absorbent zone 13 contained in the nonwoven material 10 is generally configured to absorb fluids, particularly liquids, and includes absorbent material. The absorbent material can include absorbent particles including fibers and / or other absorbent components. The absorbent zone 13 can contain a superabsorbent material in combination with a plurality of fibers. The fibers can include a blend of binder fibers, crosslinked pulp fibers and bleached chemithermomechanical pulp fibers.

[0111] Various different superabsorbent materials (SAM) can be incorporated into the absorbent zone 13. SAM is commonly provided in a particulate form and, in certain aspects, can comprise polymers of unsaturated carboxylic acids or derivatives thereof. In some forms, however, SAM can be configured in fiber form. These polymers are often rendered water insoluble, but water swellable, by crosslinking the polymer with a di- or polyfunctional internal crosslinking agent. These internally crosslinked polymers are at least partially neutralized and commonly contain pendant anionic carboxyl groups on the polymer backbone that enable the polymer to absorb aqueous fluids, such as body fluids Typically, the SAM particles are subjected to a post-treatment to crosslink the pendant anionic carboxyl groups on the surface of the particle. SAMs are manufactured by known polymerization techniques, desirably by polymerization in aqueous solution by gel polymerization. The products of this polymerization process are aqueous polymer gels, i.e., SAM hydrogels that are reduced in size to small particles by mechanical forces, then dried using drying procedures and apparatus known in the art. The drying process is followed by pulverization of the resulting SAM particles to the desired particle size. Examples of superabsorbent materials include, but are not limited to, those described in US7396584 Azad et al, US7935860 Dodge et al, US2005 / 5245393 to Azad et al, US2014 / 09606 to Bergam et al, W02008 / 027488 to Chang et al. and so forth.

[0112] In some embodiments involving SAM, the SAM may be treated by a water-soluble protective coating having a rate of dissolution selected such that the component is not substantially exposed to the aqueous liquid carrier until the highly-expanded foam has been formed and drying operations initiated that can remove the coating. Alternatively, in order to prevent or limit premature expansion during processing, the SAM may be introduced into the process at low temperatures.

[0113] Superabsorbent materials can be contained in the absorbent zone 13 in an amount from about 20% to 40% by weight, including all increments of 1 % by weight therebetween. The absorbent zone 13, for example, can contain superabsorbent materials in an amount greater than about 22% by weight, such as in an amount greater than about 25% by weight, such as in an amount greater than about 28% by weight. In various embodiments, the superabsorbent materials can be contained in the absorbent zone 13 in an amount less than about 38% by weight, such as in an amount less than about 35% by weight, such as in an amount less than about 33% by weight.

[0114] In addition to superabsorbent materials, the absorbent zone 13 can also contain various other fibers including binder fibers. For instance, binder fibers can be present in the absorbent zone 13 in an amount from about 10% by weight to about 30% by weight including all increments of 1 wt.% therebetween. For example, binder fibers can be present in the absorbent zone 13 in an amount greater than about 12% by weight, such as in an amount greater than about 15% by weight, such as in an amount greater than about 18% by weight, and in an amount less than about 28% by weight, such as in an amount less than about 25% by weight, such as in an amount less than about 23% by weight. The above weight percentages are based upon the total amount of fibers present in the absorbent zone 13.

[0115] The absorbent zone 13 can also contain various different types of cellulose fibers. For example, the absorbent zone 13 can contain crosslinked pulp fibers and bleached chemithermomechanical pulp fibers. The crosslinked pulp fibers can be contained in the absorbent zone 13 generally in an amount from about 15% by weight to about 35% by weight based upon the total amount of fibers contained in the absorbent zone 13. The crosslinked pulp fibers, for instance, can be present in the absorbent zone 13 in an amount greater than about 17% by weight, such as in an amount greater than about 20% by weight, such as in an amount greater than about 22% by weight, and in an amount less than about 33% by weight, such as in an amount less than about 30% by weight, such as in an amount less than about 28% by weight, based upon the total amount of fibers contained in the absorbent zone 13. Bleached chemithermomechanical pulp fibers can be present in the absorbent zone 13 in an amount greater than the crosslinked pulp fibers and in an amount greater than the binder fibers. The bleached chemithermomechanical pulp fibers, for instance, can be present in the absorbent zone 13 in an amount from about 45% by weight to about 65% by weight based upon the total amount of fibers present in the absorbent zone 13. The bleached chemithermomechanical pulp fibers, for instance, can be present in the absorbent zone 13 in an amount greater than about 47% by weight, such as in an amount greater than about 50% by weight, such as in an amount greater than about 52% by weight, and in an amount less than about 63% by weight, such as in an amount less than about 60% by weight, such as in an amount less than about 58% by weight, based upon the total amount of fibers contained in the absorbent zone 13.

[0116] The basis weight of the absorbent zone 13 can be from about 60 gsm to about 180 gsm, including all increments of 1 gsm therebetween. For instance, the basis weight of the absorbent zone 13 can be greater than about 65 gsm, such as greater than about 70 gsm, such as greater than about 75 gsm, such as greater than about 80 gsm, such as greater than about 85 gsm, such as greater than about 90 gsm, such as greater than about 95 gsm. The basis weight of the absorbent zone 13 can be less than about 170 gsm, such as less than about 160 gsm, such as less than about 150 gsm, such as less than about 140 gsm. The basis weight ratio between the intake zone and the absorbent zone can be between about 10:90 to about 45:55, such as from about 35:65 to about 45:55.

[0117] As shown in FIG. 1, the nonwoven material 10 further includes a transfer zone 17. In accordance with the present disclosure, the transfer zone can contain generally the same fibers in generally the same amount as the fiber furnish used to produce the intake zone 12. It was discovered that matching the fiber furnish between the intake zone 12 and the transfer zone 17 can dramatically improve toughness and peak load characteristics. For instance, the transfer zone 17 can contain binder fibers in an amount from about 10% by weight to about 40% by weight, can contain synthetic polymer fibers in an amount from about 40% by weight to about 60% by weight, and can contain crosslinked pulp fibers in an amount from about 20% by weight to about 40% by weight. Similar to the intake zone 12, for instance, the transfer zone 17 can contain binder fibers in an amount greater than about 12% by weight, such as in an amount greater than about 15% by weight, such as in an amount greater than about 17% by weight, and in an amount less than about 30% by weight, such as in an amount less than about 28% by weight, such as in an amount less than about 25% by weight, such as in an amount less than about 23% by weight, can contain synthetic polymer fibers in an amount greater than about 42% by weight, such as in an amount greater than about 45% by weight, such as in an amount greater than about 47% by weight, and in an amount less than about 58% by weight, such as in an amount less than about 55% by weight, such as in an amount less than about 53% by weight, and can contain crosslinked pulp fibers in an amount greater than about 22% by weight, such as in an amount greater than about 25% by weight, such as in an amount greater than about 27% by weight, and in an amount less than about 38% by weight, such as in an amount less than about 35% by weight, such as in an amount less than about 33% by weight.

[0118] The transfer zone 17 as shown in FIG. 1 can generally have a relatively low basis weight. For instance, the transfer zone 17 can have a basis weight of less than about 40 gsm, such as less than about 30 gsm, such as less than about 25 gsm, such as less than about 20 gsm, such as less than about 18 gsm. The basis weight of the transfer zone 17 can be greater than about 5 gsm, such as greater than about 10 gsm, such as greater than about 12 gsm. In one aspect, the transfer zone can have a basis weight of from about 12 gsm to about 40 gsm, such as from about 20 gsm to about 40 gsm, such as from about 20 gsm to about 30 gsm.

[0119] In one aspect, the transfer zone and the intake zone can have about the same basis weight. For example, the basis weight of the transfer zone can be within about 10 gsm, such as within about 5 gsm, such as within about 3 gsm of the basis weight of the intake zone. When having about the same basis weight and the same fiber furnish, the intake zone and transfer zone can be interchangeable.

[0120] In addition to the materials described above to form the different zones in the nonwoven material or multi-zone substrate, the multi-zone substrate can also contain various other additives and components. For example, wet strength additives can be added during formation of the substrate in order to help improve the relative strength of the multi-zone substrate.

[0121] Such strength additives suitable for use with paper making fibers and the manufacture of paper tissue are known in the art. Temporary wet strength additives may be cationic, nonionic or anionic. Examples of such temporary wet strength additives include PAREZ™ 631 NC and PAREZ(R) 725 temporary wet strength resins that are cationic glyoxylated polyacrylamides available from Cytec Industries, located at West Paterson, N.J. These and similar resins are described in US3556932 to Coscia et al. and US3556933 to Williams et al. Additional examples of temporary wet strength additives include dialdehyde starches and other aldehyde containing polymers such as those described in US6224714 to Schroeder et al.; US6274667 to Shannon et al.; US6287418 to Schroeder et al.; and US6365667to Shannon et al., and so forth.

[0122] Permanent wet strength agents comprising cationic oligomeric or polymeric resins may also be used in the present disclosure. Polyamide-polyamine-epichlorohydrin type resins such as KYMENE 557H sold by Solenis are the most widely used permanent wet-strength agents and are suitable for use in the present disclosure. Such materials have been described in the following US3700623 to Keim; US3772076 to Keim; US3855158 to Petrovich et al.; US3899388to Petrovich et al.; US4129528 to Petrovich et al.; US4147586 to Petrovich et al.; US4222921 to van Eenam and so forth. Other cationic resins include polyethylenimine resins and aminoplast resins obtained by reaction of formaldehyde with melamine or urea. Permanent and temporary wet strength resins may be used together in the manufacture of composite cellulosic products of the present disclosure. Further, dry strength resins may also optionally be applied to the composite cellulosic webs of the present disclosure. Such materials may include, but are not limited to, modified starches and other polysaccharides such as cationic, amphoteric, and anionic starches and guar and locust bean gums, modified polyacrylamides, carboxymethylcellulose, sugars, polyvinyl alcohol, chitosan, and the like.

[0123] When a wet strength additive is used, it is preferable to select an additive that is compatible with the foam agent used for the foam process. For example, when a strength additive is a cationic resin, due to incompatibility between a cationic and an anionic substance, a cationic surfactant is preferably used as a foam agent, or vice versa. A non-ionic surfactant is usually compatible with any cationic and anionic strength additives.

[0124] One or more wet strength additives can be incorporated into only one of the zones of the nonwoven material 10. For instance, a wet strength additive can be incorporated into the intake zone, can be incorporated into the absorbent zone, and / or can be incorporated into the transfer zone. In one embodiment, at least one wet strength additive is incorporated into all three zones.

[0125] If used, such wet strength additives can comprise between about 0.01 and about 5% of the dry weight of cellulose fibers contained in the multi-zone substrate. In certain embodiments, the strength additives can comprise between about 0.05% and about 2% of the dry weight of cellulose fibers or even between about 0.1% and about 1 % of the dry weight of cellulose fibers.

[0126] Still other additional components may be added to multi-zone substrate materials. For materials that are formed utilizing foam forming processes, other additional components should be reviewed as to ensure they do not significantly interfere with the formation of the foam, the hydrogen bonding as between the cellulosic fibers or other desired properties of the material. As examples, additional additives may include one or more pigments, opacifying agents, anti-microbial agents, pH modifiers, skin benefit agents, odor absorbing agents, fragrances, thermally expandable microspheres, surfactants or hydrophilic agents, foam particles (such as, pulverized foam particles), and so forth as desired to impart or improve one or more physical or aesthetic attributes. In certain embodiments, the multi-zone substrate may include skin benefit agents such as, for example, antioxidants, astringents, conditioners, emollients, deodorants, external analgesics, film formers, humectants, hydrotropes, pH modifiers, surface modifiers, skin protectants, and so forth.

[0127] Nonwoven materials, as described herein can be preferably formed through a foam forming process. FIG. 2 provides a schematic of an exemplary apparatus 11 that can be used as part of a foam forming process to manufacture a nonwoven material 10 that is a foam formed product. The apparatus 11 of FIG. 2 can include a first tank 14 configured for holding a first fluid supply 16. In some embodiments, the first fluid supply 16 can be a foam. The first fluid supply 16 can include a fluid provided by a supply of fluid 18. In some embodiments, the first fluid supply 16 can include a plurality fibers provided by a supply of fibers 20, and preferably includes at least some absorbent fibers. However, in other embodiments, the first fluid supply 16 can be free from a plurality of fibers altogether. The first fluid supply 16 can also include a surfactant provided by a supply of surfactant 22. In some embodiments, the first tank 14 can include a mixer 24, as will be discussed in more detail below. The mixer 24 can mix (e.g., agitate) the first fluid supply 16 to mix the fluid, fibers (if present), and surfactant with air, or some other gas, to create a foam. The mixer 24 can also mix the foam with fibers (if present) to create a foam suspension of fibers in which the foam holds and separates the fibers to facilitate a distribution of the fibers within the foam (e.g., as an artifact of the mixing process in the first tank 14). Uniform fiber distribution can promote desirable absorbent material 10 including, for example, strength and the visual appearance of quality.

[0128] The apparatus 11 can also include a second tank 26 configured for holding a second fluid supply 28. In some embodiments, the second fluid supply 28 can be a foam. The second fluid supply 28 can include a fluid provided by a supply of fluid 30 and a surfactant provided by a supply of surfactant 32. In some preferred embodiments, such as depicted in FIG. 2, the second fluid supply 28 is free from fibers. In other embodiments, the second fluid supply 28 can include a plurality of fibers in addition to or as an alternative to the fibers being present in the first fluid supply 16. In some embodiments, the second tank 26 can include a mixer 34. The mixer 34 can mix the second fluid supply 28 to mix the fluid and surfactant with air, or some other gas, to create a foam.

[0129] In some embodiments, the apparatus 11 can also include a third tank 31 configured for holding a third fluid supply 33. In some embodiments, the third fluid supply 33 can be a foam. The third fluid supply 33 can include a fluid provided by a supply of fluid 35 and a plurality of fibers provided by a supply of fibers 37, and preferably includes at least some synthetic fibers. The third fluid supply 33 can also include a surfactant provided by a supply of surfactant 39. In some embodiments, the third tank 31 can include a mixer 41. The mixer 41 can mix the third fluid supply 33 to mix the fluid and surfactant with air, or some other gas, to create a foam.

[0130] In some embodiments, the apparatus 11 can also include a fourth tank 66 configured for holding a fourth fluid supply 68. In some embodiments, the fourth fluid supply 68 can be a foam. The fourth fluid supply 68 can include a fluid provided by a supply of fluid 69 and a plurality of fibers provided by a supply of fibers 70. The fourth fluid supply 68 can also include a surfactant provided by a supply of surfactant 71. In some embodiments, the fourth tank 66 can include a mixer 72. The mixer 72 can mix the fourth fluid supply 68 to mix the fluid and surfactant with air, or some other gas, to create a foam.

[0131] In tanks 14, 26, 31 , 66 the first fluid supply 16, the second fluid supply 28, the third fluid supply 33, and the fourth fluid supply 68, respectively, can be acted upon to form a foam. In some embodiments, the foaming fluid and other components are acted upon so as to form a porous foam having an air content greater than about 50% by volume and desirably an air content greater than about 60% by volume. In certain aspects, the highly-expanded foam is formed having an air content of between about 60% and about 95% and in further aspects between about 65% and about 85%. In certain embodiments, the foam may be acted upon to introduce air bubbles such that the ratio of expansion (volume of air to other components in the expanded stable foam) is greater than 1 :1 and in certain embodiments the ratio of another components can be between about 1.1 :1 and about 20:1 or between about 1.2:1 and about 15:1 or between about 1.5:1 and about 10:1 or even between about 2:1 and about 5:1.

[0132] The foam can be generated by one or more means known in the art. Examples of suitable methods include, without limitation, aggressive mechanical agitation such as by mixers 24, 34, 41 , 72 injection of compressed air, and so forth. Mixing the components through the use of a high-shear, high-speed mixer is particularly well suited for use in the formation of the desired highly-porous foams. Various high-shear mixers are known in the art and believed suitable for use with the present disclosure. High-shear mixers typically employ a tank holding the foam precursor and / or one or more pipes through which the foam precursor is directed. The high-shear mixers may use a series of screens and / or rotors to work the precursor and cause aggressive mixing of the components and air. In a particular embodiment, the first tank 14, the second tank 26, the third tank 31 , and / or the fourth tank 66 is provided having therein one or more rotors or impellers and associated stators. The rotors or impellors are rotated at high speeds in order to cause flow and shear. Air may, for example, be introduced into the tank at various positions or simply drawn in by the action of the mixers 24, 34, 41 , 72. While the specific mixer design may influence the speeds necessary to achieve the desired mixing and shear, in certain embodiments suitable rotor speeds may be greater than about 500 rpm and, for example, be between about 1000 rpm and about 6000 rpm or between about 2000 rpm and about 4000 rpm. In other embodiments, suitable rotor speeds may be less than 500 rpm.

[0133] In addition, it is noted the foaming process can be accomplished in a single foam generation step or in sequential foam generation steps for the first tank 14, the second tank 26, the third tank 31 , and / or the fourth tank 66. For example, in one embodiment, all of the components of the first fluid supply 16 in the first tank 14 (e.g., the supply of the fluid 18, fibers 20, and surfactant 22) may be mixed together to form a slurry from which a foam is formed. Alternatively, one or more of the individual components may be added to the foaming fluid, an initial mixture formed (e.g. a dispersion or foam), after which the remaining components may be added to the initially foamed slurry and then all of the components acted upon to form the final foam. In this regard, the fluid 18 and surfactant 22 may be initially mixed and acted upon to form an initial foam prior to the addition of any solids. Fibers, if desired, may then be added to the water / surfactant foam and then further acted upon to form the final foam. As a further alternative, the fluid 18 and fibers 20, such as a high density cellulose pulp sheet, may be aggressively mixed at a higher consistency to form an initial dispersion after which the foaming surfactant 22, additional water and other components, such as synthetic fibers, are added to form a second mixture which is then mixed and acted upon to form the foam.

[0134] The foam density of the foam forming the first fluid supply 16 in the first tank 14, the foam forming the second fluid supply 28 in the second tank 26, the third fluid supply 33 in the third tank 31, and / or the fourth fluid supply 68 in the fourth tank 66 can vary depending upon the particular application and various factors, such as the fiber stock used. In some implementations, for example, the foam density of the foam can be greater than about 100 g / L, such as greater than about 250 g / L, such as greater than about 300 g / L. The foam density is generally less than about 800 g / L, such as less than about 500 g / L, such as less than about 400 g / L, such as less than about 350 g / L. In some implementations, for example, a lower density foam is used having a foam density of generally less than about 350 g / L, such as less than about 340 g / L, such as less than about 330 g / L.

[0135] The apparatus 11 can also include a first pump 36, a second pump 38, third pump 43, and fourth pump 73. The first pump 36 can be in fluid communication with the first fluid supply 16 and can be configured for pumping the first fluid supply 16 to transfer the first fluid supply 16. The second pump 38 can be in fluid communication with the second fluid supply 28 and can be configured for pumping the second fluid supply 28 to transfer the second fluid supply 28. The third pump 43 can be in fluid communication with the third fluid supply 33 and can be configured for pumping the third fluid supply 33 to transfer the third fluid supply 33. The fourth pump 73 can be in fluid communication with the fourth fluid supply 68 and can be configured for pumping the fourth fluid supply 68 to transfer the fourth fluid supply 68. In some embodiments, the first pump 36, the second pump 38, the third pump 43, and / or the fourth pump 73 can be a progressive cavity pump or a centrifugal pump, however, it is contemplated that other suitable types of pumps can be used.

[0136] As depicted in FIG. 2, the apparatus 11 can also include a component feed system 40. The component feed system 40 can be used to deliver a supply of component 44, if one is desired for the multi-zone substrate 10, by delivering the component 44 to one or more fluid supply 16, 28, 33, 68 or directly to the headbox 80. One exemplary component feed system 40 that can be used can include a component supply area 42 for receiving a supply of a component. The component feed system 40 can also include an outlet conduit 46. The component feed system 40 can also include a hopper 48. The hopper 48 can be coupled to the component supply area 42 and can be utilized for refiling the supply of the component 44 to the component supply area 42.

[0137] In some embodiments, the component feed system 40 can include a bulk solids pump. Some examples of bulk solids pumps that may be used herein can include systems that utilize screws / augers, belts, vibratory trays, rotating discs, or other known systems for handling and discharging the supply of the component 44. Other types of feeders can be used for the component feed system 40, such as, for example, an ingredient feeder, such as those manufactured by Christy Machine & Conveyor, Fremont, Ohio. The component feed system 40 can also be configured as a conveyor system in some embodiments.

[0138] In some embodiments, the component feed system 40 can also include a pressure control system 50. In some embodiments, the pressure control system 50 can include a housing 52. The housing 52 can form a pressurized seal volume around the component feed system 40. In other embodiments, the pressure control system 50 can be formed as an integral part to the structure component feed system 40 itself, such that a separate housing 52 surrounding the component feed system 40 may not be required. The pressure control system 50 can also include a bleed orifice 54 in some embodiments.

[0139] The supply of the component 44 can be in the form of a particulate and / or a fiber and / or a powder. In one embodiment as described herein, the supply of the component 44 can be superabsorbent material (SAM) in particulate form. In some embodiments, SAM can be in the form of a fiber. Of course, other types of components, as previously discussed, are also contemplated as being utilized in the apparatus 11 and methods for forming an absorbent material 10 as described herein. The component feed system 40 as described herein can be particularly beneficial for a supply of component 44 that is most suitably maintained in a dry environment with minimal of exposure to fluid or foam utilized in the apparatus 11 and methods described herein.

[0140] The apparatus 11 can also include a first mixing junction 56 and a second mixing junction 58. In preferred embodiments, the first mixing junction 56 can be an eductor (also commonly referred to as a jet pump). The first mixing junction 56 can be in fluid communication with the outlet conduit 46 of the component feed system 40 and in fluid communication with the second fluid supply 28. The first mixing junction 56 can include a first inlet 60 and a second inlet 62. The first inlet 60 can be in fluid communication with the supply of the component 44 via the outlet conduit 46. The second inlet 62 can be in fluid communication with the second fluid supply 28. The first mixing junction 56 can also include a discharge 64. In preferred embodiments, the first mixing junction 56 can be configured as a co-axial eductor with the axis of the first inlet 60 being co-axial with the axis of the outlet conduit 46 that provides the supply of the component 44. The first mixing junction 56 can also be configured such that the discharge axis of the discharge 64 is co-axial with the outlet axis of the outlet conduit 46. As such, the first mixing junction 56 can be configured such that the axis of the first inlet 60 can be co-axial with the axis of the discharge 64 of the first mixing junction 56. The second inlet 62 providing the second fluid supply 28 to the first mixing junction 56 can be set up to enter the first mixing junction 56 on a side of the first mixing junction 56.

[0141] When configured as an eductor, the first mixing junction 56 can mix the supply of the component 44 from the component feed system 40 with the second fluid supply 28. By transferring the second fluid supply 28 into the first mixing junction 56 at the second inlet 62 and through the first mixing junction 56, the second fluid supply 28 provides a motive pressure to the supply of the component 44. The motive pressure can create a vacuum on the supply of the component 44 and the component feed system 40 to help draw the supply of the component 44 to mix and be entrained in the second fluid supply 28. In some embodiments, the motive pressure can create a vacuum on the supply of the component 44 of less than 1 ,5in Hg, however, in other embodiments, the motive pressure could create a vacuum on the supply of the component 44 of 5in . Hg or more, or 10in Hg or more.

[0142] The pressure control system 50 can help manage proper distribution and entrainment of the supply of the component 44 to the second fluid supply 28. For example, when the second fluid supply 28 creates a motive pressure on the component feed system 40, the vacuum pulling on the supply of the component 44 may cause additional air to be entrained in the second fluid supply 28. In some circumstances, entraining additional air in the second fluid supply 28 may be desired, however, in other circumstances, it may be desirable to control the gas content of the second fluid supply 28 while inputting the supply of the component 44 to the second fluid supply 28 at the first mixing junction 56. For example, in some circumstances where the second fluid supply 28 is a foam, the amount of gas content in the foam may be desired to be kept relatively fixed as the foam passes through the first mixing junction 56. Thus, the pressure control system 50 can control the pressure on the component feed system 40 to help counteract the motive pressure on the supply of the component 44 and the component feed system 40 created by the second fluid supply 28.

[0143] In some embodiments, the pressure control system 50 can include sealing off the component feed system 40. For example, as discussed above, the pressure control system 50 can include a housing 52 to provide a seal on the component feed system 40. Sealing the component feed system 40 can help to prevent additional air entrainment in the second fluid supply 28 when the supply of the component 44 is introduced into the second fluid supply 28 in the first mixing junction 56. However, in some embodiments, it may be beneficial to also include additional capability to the pressure control system 50. For example, in some embodiments, the pressure control system 50 can include a bleed orifice 54. The bleed orifice 54 can be configured to bleed-in pressure, such as atmospheric air pressure, to provide additional pressure control of the component feed system 40. It has been discovered that by providing a bleed-in orifice 54 to provide some bleed-in of atmospheric air pressure to the component feed system 40, back-splashing of the second fluid supply 28 in the first mixing junction 56 can be reduced or eliminated. Reducing back-splashing of the second fluid supply 28 in the first mixing junction 56 can help prevent the component feed system 40 from becoming clogged or needing to be cleaned, especially where the component feed system 40 may be delivering a dry component, such as particulate SAM.

[0144] Additionally or alternatively, the pressure control system 50 can be configured to provide additional positive pressure to prevent back-filling of the component feed system 40 in some circumstances, such as if a downstream obstruction occurs in the apparatus 11 beyond the first mixing junction 56. In such a case of an obstruction creating an increased pressure, the second fluid supply 28 may have a desire to back-fill the component feed system 40. Back-filling of fluid into the component feed system 40 can be detrimental to processing, especially where the supply of the component 44 is a component best kept in dry conditions, such as SAM. A pressure control system 50 configured to be able to provide positive pressure to the component feed system 40 can help prevent such back-filling of the component feed system 40.

[0145] It is also contemplated that other additional aspects of a pressure control system 50 could be utilized to maintain the pressure to a suitable level for the component feed system 40, including, but not limited to, supplying vacuum to the component feed system 40 in addition to or alternative to the air bleed-in at the bleed orifice 54 and / or the positive pressure described above.

[0146] The first mixing junction 56 can also provide pressure control on the transfer of the second fluid supply 28 including the component 44 as it exits the discharge 64 of the first mixing junction 56 as compared to when the second fluid supply 28 enters the first mixing junction 56. The second fluid supply 28 can be transferred at a second fluid pressure prior to the first mixing junction 56. The second fluid supply 28 including the component from the supply of the component 44 can exit the discharge 64 of the first mixing junction 56 at a discharge pressure. The pressure difference between the second fluid pressure prior to the first mixing junction 56 and the discharge pressure can be controlled. In some embodiments, this pressure difference can be controlled by varying the flow rate of the second fluid supply 28 or through the positioning of the outlet conduit 46 in the first mixing junction 56. In some embodiments, it is preferable to control the pressure difference between the second fluid pressure prior to the first mixing junction 56 and the discharge pressure to be less than or equal to 5 pounds per square inch.

[0147] It is to be noted that while a single outlet conduit 46 of the component feed system 40 and a single first mixing junction 56 is illustrated in FIG. 2, it is contemplated that the outlet conduit 46 can be split into two or more conduits to feed two or more first mixing junctions 56 for mixing the supply of the component 44 with the second fluid supply 28. In such a configuration, the second fluid supply 28 can include as many conduits as there are first mixing junctions 56. By having more than one outlet conduit 46 and more than one first mixing junction 56 to mix the supply of the component 44 with the second fluid supply 28, a greater flow rate of the second fluid supply 28 including the component from the supply of the component 44 can be achieved.

[0148] Referring to FIG. 2, the apparatus 11 can include a second mixing junction 58 in some embodiments. The second mixing junction 58 can provide the functionality of mixing the second fluid supply 28 including the component from the supply of the component 44 with the first fluid supply 16. As the second fluid supply 28 including the component from the supply of the component 44 exits the discharge 64 of the first mixing junction 56 it can be transferred to the second mixing junction 58. The first fluid supply 16 can be delivered to the second mixing junction 58 by the first pump 36. The second mixing junction 58 can mix the first fluid supply 16 and any of its components (e.g. , fluid 18, fibers 20, surfactant 22) with the second fluid supply 28 and any of its components (e.g., fluid 30, surfactant 32) and the component from the supply of the component 44 to deliver the mixture of the first fluid supply 16, the second fluid supply 28, and the component 44 to a headbox 80.

[0149] Alternatively, in some embodiments, a second mixing junction 58 can be omitted from the apparatus 11 and the second fluid supply 28 including the component from the supply of the component 44 can be delivered to headbox 80.

[0150] As illustrated in FIGS. 2 and 3, the headbox 80 can include one or more z-directional dividers 78a, 78b for separating different inputs to the headbox 80 in forming different zones of the nonwoven material 10. The third fluid supply 33 and any of its components (e.g., fluid 35, fibers 37, surfactant 39) can be delivered to the inlet 81 of the headbox 80 via the third pump 43 and can be delivered above the first z-directional divider 78a in a first z-directional zone 85a of the headbox 80. The output of the second mixing junction 58 including the mixture of the first fluid supply 16 and any of its components (e.g., fluid 18, fibers 20, surfactant 22), the second fluid supply 28 and any of its components (e.g., fluid 30, surfactant 32), and the component 44 can be delivered to the inlet 81 of the headbox 80 below the first z-directional divider 78a and above the second z-directional divider 78b in a second z- directional zone 85b of the headbox 80. The fourth fluid supply 68 and any of its components (e.g., fluid 69, fibers 70, surfactant 71) can be delivered to the inlet 81 of the headbox 80 via the fourth pump 73 and can be delivered below the second z-directional divider 78b in a third z-directional zone 85c of the headbox 80. Such a configuration of two z-directional dividers 78a, 78b can be beneficial for forming a three-zone substrate 10, such as described above and illustrated in FIG. 1.

[0151] The headbox 80 can provide a resultant slurry 76 to a forming surface 94. The forming surface 94 can be a foraminous sheet, such as a woven belt or screen, or any other suitable surface for accepting the resultant slurry 76.

[0152] The apparatus 11 can also include a dewatering system 96 that can be configured to remove liquid from the resultant slurry 76 (e.g. , forming fluid) on the forming surface 94. In some embodiments, the dewatering system 96 can be configured to provide a vacuum to the resultant slurry 76 to pull liquid from the resultant slurry 76, and in doing so, can turn the resultant slurry 76 including the plurality of fibers 20 and the component 44, if present, into an multi-zone substrate 10. In some embodiments, the dewatering system 96 can begin dewatering on fibers and / or components as they are still within the headbox 80.

[0153] Dewatering systems 96 drawing liquid from the resultant slurry 76 can also unintentionally draw components 44 (such as particulate SAM) through the forming surface 94, and / or cause components 44 to become lodged in the forming surface 94. Not only can this cause substrates 10 to be formed that do not include intended amounts of the component 44, but components 44 becoming lodged in the forming surface 94 and / or being drawn through the forming surface 94 can cause processing issues, including, but not limited to, reduced dewatering and / or increased demands for drying of the resultant slurry 76, machine down-time for cleaning, and increased complexity for dewatered liquid by including such components 44. Forming a multi-zone substrate 10 including components 44 in a fluid, such as foam forming, can exacerbate the problem of component 44 movement in the resultant slurry 76 in comparison to dry forming techniques, such as air-laid formation techniques or adhesive-based techniques.

[0154] Forming a transfer zone 17 as part of the substrate 10 that is directly against the forming surface 94 can help protect the components 44 of the substrate 12 (such as SAM in the absorbent zone 13). The transfer zone 17 can protect the components 44 of the substrate 10 from the forming surface to help ensure the components 44 remain in the substrate 10, or at least reduce the possibility for the components 44 to become lodged in the forming surface 94 or be drawn through the forming surface 94. Additionally, the transfer zone 17 can help retain components 44 within the absorbent material 10 as it is potentially transported for further processing and / or use in other products in which the multi-zone substrate 10 may be incorporated within, such as personal care absorbent articles. Forming the transfer zone 17 inline as a composite with the absorbent zone 13 where at least some fibers of the transfer zone 17 are mixed with at least some of the fibers of the absorbent zone 13 at the interface 19, eliminates the need for additional processing to form a composite absorbent substrate 10, such as the use of adhesive to couple a separate transfer zone 17 to an absorbent zone 13. Eliminating adhesive can result in reduced processing equipment and raw material cost and can also lead to improved fluid handling properties of the absorbent substrate 10. Additionally, forming a transfer zone 17 as part of the substrate 10 can also provide improved integrity and tensile strength for the absorbent material 10 providing enhanced processing capability of the substrate 10.

[0155] While the apparatus 11 and method described in FIG. 2 is one exemplary embodiment for forming a multi-zone substrate 10, an alternative embodiment of an apparatus 111 and method of forming an multi-zone substrate 10 is depicted in FIG. 4. The apparatus 111 of FIG. 4 can be used as part of a similar foam forming process as described above with respect to FIG. 2, however, the headbox 180 is a vertical twin former as is known in the art. The headbox 180 can include first and second foraminous elements 119, 121. The first and second foraminous elements 119, 121 can help define an interior volume of the headbox 180. The headbox 180 can include a first divider 178a and a second divider 178b that can provide first, second, and third z-directional zones 185a, 185b, 185c within the headbox 180 similar to the discussion above with the headbox 80 in FIG. 3, but the zones 185a, 185b, 185c in FIG. 4 are in a vertical orientation with respect to one another due to the vertical orientation of the headbox 180. The apparatus 111 can include a dewatering system 196 that can include a series of vacuum elements 197 disposed adjacent each foraminous element 119, 121.

[0156] In some embodiments, a first supply of fibers 20 can be supplied to the headbox 180, and in some embodiments, the first supply of fibers 20 can be in a foam. The supply of the fibers 20 can include at least some absorbent fibers. The supply of the component 44 can also be supplied directly to the headbox 180, and in some embodiments, the supply of the component 44 may be in a foam. The supply of the fibers 20 and component 44 can be delivered to the second z-directional zone 185b of the headbox 180. It is to be noted that in some embodiments, the second z-directional zone 185b of the headbox 180 may only be provided with the supply of the component 44 and not a supply of fibers 20. In some embodiments, a second supply of fibers 123 can be provided to the headbox 180, and in some embodiments, can be in a foam. The second supply of fibers 123 can be provided to the first z- directional zone 185a of the headbox 180. In some embodiments, a third supply of fibers 125 can be provided to the headbox 180, and in some embodiments, can be in a foam. The third supply of fibers 125 can be provided to the third z-directional zone 185c of the headbox 180. The fibers 20, 123, 125 and component 44 can be processed through the headbox 180 in a machine direction 185 towards the outlet 182 of the headbox 180 to provide an absorbent material 10, similar to the apparatus 11 described in FIG. 2. The apparatuses 11 , 111 as described herein can also include a drying system 98 to further dry and / or cure the absorbent material 10. The drying system 98 can apply heat to the absorbent material 10, such as by providing heated air in a through-air drying system.

[0157] In some embodiments, the apparatus 11 , 111 can include a winding system 99 (as shown in FIG. 2) that can be configured to wind the absorbent material 10 in a roll fashion. In other embodiments, the apparatus 11 , 111 can festoon the absorbent material 10 or collect the absorbent material 10 in any other suitable configuration, such as spooling.

[0158] As described above, the foam forming processes as described herein can include a foaming fluid. In some embodiments, the foaming fluid can comprise between about 85% to about 99.99% of the foam (by weight). In some embodiments, the foaming fluid used to make the foam can comprise at least about 85% of the foam (by weight). In certain embodiments, the foaming fluid can comprise between about 90% and about 99.9% % of the foam (by weight). In certain other embodiments, the foaming fluid can comprise between about 93% and 99.5% of the foam or even between about 95% and about 99.0% of the foam (by weight). In preferred embodiments, the foaming fluid can be water, however, it is contemplated that other processes may utilize other foaming fluids.

[0159] The foam forming processes as described herein can utilize one or more surfactants. The fibers and surfactant, together with the foaming liquid and any additional components, can form a stable dispersion capable of substantially retaining a high degree of porosity for longer than the drying process. In this regard, the surfactant is selected so as to provide a foam having a foam half life of at least 2 minutes, more desirably at least 5 minutes, and most desirably at least 10 minutes. A foam half life can be a function of surfactant types, surfactant concentrations, foam compositions / solid level and mixing power / air content in a foam. The foaming surfactant used in the foam can be selected from one or more known in the art that are capable of providing the desired degree of foam stability. In this regard, the foaming surfactant can be selected from anionic, cationic, nonionic and amphoteric surfactants provided they, alone or in combination with other components, provide the necessary foam stability, or foam half life. As will be appreciated, more than one surfactant can be used, including different types of surfactants, as long as they are compatible, and more than one surfactant of the same type. For example, a combination of a cationic surfactant and a nonionic surfactant or a combination of an anionic surfactant and a nonionic surfactant may be used in some embodiments due to their compatibilities. However, in some embodiments, a combination of a cationic surfactant and an anionic surfactant may not be satisfactory to combine due to incompatibilities between the surfactants. In one aspect, a primary surfactant may be used to produce a foam and a secondary surfactant can be applied to the nonwoven material during processing. Anionic surfactants believed suitable for use with the present disclosure include, without limitation, anionic sulfate surfactants, alkyl ether sulfonates, alkylaryl sulfonates, or mixtures or combinations thereof. Examples of alkylaryl sulfonates include, without limitation, alkyl benzene sulfonic acids and their salts, dialkylbenzene disulfonic acids and their salts, dialkylbenzene sulfonic acids and their salts, alkylphenol sulfonic acids / condensed alkylphenol sulfonic acids and their salts, or mixture or combinations thereof. Examples of additional anionic surfactants believed suitable for use in the present disclosure include alkali metal sulforicinates, sulfonated glyceryl esters of fatty acids such as sulfonated monoglycerides of coconut oil acids, salts of sulfonated monovalent alcohol esters such as sodium oleylisethianate, metal soaps of fatty acids, amides of amino sulfonic acids such as the sodium salt of oleyl methyl tauride, sulfonated products of fatty acids nitriles such as palmitonitrile sulfonate, alkali metal alkyl sulfates such as sodium lauryl sulfate, ammonium lauryl sulfate or triethanolamine lauryl sulfate, ether sulfates having alkyl groups of 8 or more carbon atoms such as sodium lauryl ether sulfate, ammonium lauryl ether sulfate, sodium alkyl aryl ether sulfates, and ammonium alkyl aryl ether sulfates, sulphuric esters of polyoxyethylene alkyl ether, sodium salts, potassium salts, and amine salts of alkylnapthylsulfonic acid. Certain phosphate surfactants including phosphate esters such as sodium lauryl phosphate esters or those available from the Dow Chemical Company under the tradename TRITON are also believed suitable for use herewith. A particularly desired anionic surfactant is sodium dodecyl sulfate (SDS).

[0160] Cationic surfactants are also believed suitable for use with the present disclosure for manufacturing some embodiments of substrates. In some embodiments, such as those including superabsorbent material, cationic surfactants may be less preferable to use due to potential interaction between the cationic surfactant(s) and the superabsorbent material, which may be anionic. Foaming cationic surfactants include, without limitation, monocarbyl ammonium salts, dicarbyl ammonium salts, tricarbyl ammonium salts, monocarbyl phosphonium salts, dicarbyl phosphonium salts, tricarbyl phosphonium salts, carbylcarboxy salts, quaternary ammonium salts, imidazolines, ethoxylated amines, quaternary phospholipids and so forth. Examples of additional cationic surfactants include various fatty acid amines and amides and their derivatives, and the salts of the fatty acid amines and amides. Examples of aliphatic fatty acid amines include dodecylamine acetate, octadecylamine acetate, and acetates of the amines of tallow fatty acids, homologues of aromatic amines having fatty acids such as dodecylanalin, fatty amides derived from aliphatic diamines such as undecylimidazoline, fatty amides derived from aliphatic diamines such as undecylimidazoline, fatty amides derived from disubstituted amines such as oleylaminodiethylamine, derivatives of ethylene diamine, quaternary ammonium compounds and their salts which are exemplified by tallow trimethyl ammonium chloride, dioctadecyldimethyl ammonium chloride, didodecyldimethyl ammonium chloride, dihexadecyl ammonium chloride, alkyltrimethylammonium hydroxides, dioctadecyldimethylammonium hydroxide, tallow trimethylammonium hydroxide, trimethylammonium hydroxide, methylpolyoxyethylene cocoammonium chloride, and dipalmityl hydroxyethylammonium methosulfate, amide derivatives of amino alcohols such as beta-hydroxylethylstearylamide, and amine salts of long chain fatty acids. Further examples of cationic surfactants believed suitable for use with the present disclosure include benzalkonium chloride, benzethonium chloride, cetrimonium bromide, distearyldimethylammonium chloride, tetramethylammonium hydroxide, and so forth.

[0161] Nonionic surfactants believed suitable for use in the present disclosure include, without limitation, condensates of ethylene oxide with a long chain fatty alcohol or fatty acid, condensates of ethylene oxide with an amine or an amide, condensation products of ethylene and propylene oxides, fatty acid alkylol amide and fatty amine oxides. Various additional examples of non-ionic surfactants include stearyl alcohol, sorbitan monostearate, octyl glucoside, octaethylene glycol monododecyl ether, lauryl glucoside, cetyl alcohol, cocamide MEA, monolaurin, polyoxyalkylene alkyl ethers such as polyethylene glycol long chain (12-14C) alkyl ether, polyoxyalkylene sorbitan ethers, polyoxyalkylene alkoxylate esters, polyoxyalkylene alkylphenol ethers, ethylene glycol propylene glycol copolymers, polyvinyl alcohol, alkylpolysaccharides, polyethylene glycol sorbitan monooleate, octylphenol ethylene oxide, and so forth. Non-ionic surfactants may be preferable when foam forming absorbent materials 10 with SAM. If there is residual ionic surfactant, the increase in ionic strength in the insult can reduce SAM swelling for use of the absorbent materials 10 in personal care absorbent articles.

[0162] The foaming surfactant can be used in varying amounts as necessary to achieve the desired foam stability and air-content in the foam. In certain embodiments, the foaming surfactant can comprise between about 0.005% and about 5% of the foam (by weight). In certain embodiments the foaming surfactant can comprise between about 0.05% and about 3% of the foam or even between about 0.05% and about 2% of the foam (by weight).

[0163] As noted above, the apparatus 11 , 111 and methods described herein can include providing a fibers from a supply of fibers 20, 37, 70, 123, 125. In some embodiments, the fibers can be suspending in a fluid supply 16, 28, 33, 68 that can be a foam. The foam suspension of fibers can provide one or more supply of fibers. As described above, fibers utilized herein can include cellulose fibers and / or synthetic fibers. In some embodiments, a fiber supply 20, 37, 70, 123, 125 can include only cellulose fibers or only synthetic fibers. In other embodiments, a fiber supply 20, 37, 70, 123, 125 can include a mixture of cellulose fibers and synthetic fibers. Some fibers being utilized herein can be absorbent, whereas other fibers utilized herein can be non-absorbent. Non-absorbent fibers can provide features for the substrates that are formed from the methods and apparatuses described herein, such as improved intake or distribution of fluids. In some embodiments, a fluid supply 16, 28, 33, 68 can include binder fibers (as described above) that can be provided along with or independent of the supply of the fibers 20, 37, 70, 123, 125 or the supply of the component 44.

[0164] Binder fibers, when used, may be added proportionally to the other components to achieve the desired fiber ratios and structure while maintaining the total solids content of the foam below the amounts stated above. As an example, in some embodiments, binder fibers can comprise between about 0% and about 50% of the total fiber weight, and more preferably, between about 5% to about 40% of the total fiber weight in some embodiments.

[0165] In some embodiments, if a fluid supply 16, 28, 33, 68 is configured as a foam the foam may optionally also include one or more foam stabilizers known in the art and that are compatible with the components of the foam and further do not interfere with the hydrogen bonding as between the cellulosic fibers. Foam stabilizing agents believed suitable for use in the present disclosure, without limitation, one or more zwitterionic compounds, amine oxides, alkylated polyalkylene oxides, or mixture or combinations thereof. Specific examples of foam stabilizers includes, without limitation, cocoamine oxide, isononyldimethylamine oxide, n-dodecyldimethylamine oxide, and so forth.

[0166] In some embodiments, if utilized, the foam stabilizer can comprise between about 0.01 % and about 2 % of the foam (by weight). In certain embodiments, the foam stabilizer can comprise between about 0.05% and 1% of the foam or even between about 0.1 and about 0.5% of the foam (by weight).

[0167] As mentioned above, foam forming processes can include adding one or more components 44 as additional additives that will be incorporated into the absorbent material 10, such as SAM. In some embodiments incorporating SAM, the SAM can comprise between about 0% and about 40% of the foam (by weight). In certain embodiments, SAM can comprise between about 1% and about 30% of the foam (by weight) or even between about 10% and about 30% of the foam (by weight).

[0168] If used, wet and dry strength additives can comprise between about 0.01 and about 5% of the dry weight of cellulose fibers. In certain embodiments, the strength additives can comprise between about 0.05% and about 2% of the dry weight of cellulose fibers or even between about 0.1 % and about 1 % of the dry weight of cellulose fibers.

[0169] When employed, miscellaneous components that may also be used in the absorbent material (as described above, such as, pigments, anti-microbial agents, etc.) can desirably comprise less than about 2% of the foam (by weight) and still more desirably less than about 1% of the foam (by weight) and even less than about 0.5% of the foam (by weight).

[0170] In some embodiments, the solids content, including the fibers or particulates contained herein, desirably comprise no more than about 40% of the foam. In certain embodiments the cellulosic fibers can comprise between about 0.1% and about 5% of the foam or between about 0.2 and about 4% of the foam or even between about 0.5% and about 2% of the foam.

[0171] The methods and apparatuses 11 , 111 as described herein can be beneficial for forming one or more nonwoven materials 10. The nonwoven materials 10 as described herein can be useful as components of personal care products. For example, in one embodiment, the nonwoven material 10 as described herein can be an absorbent composite for personal care absorbent articles. The nonwoven materials 10 as described herein may also be beneficial for using in other products, such as, but not limited to facial tissues, bath tissues, wipes, and wipers.

[0172] The nonwoven substrate made in accordance with the present disclosure can be incorporated into all different types of absorbent articles. The absorbent article, for instance, can be a diaper, a child training pant, or other child absorbent pant. The absorbent article can also be an adult incontinence product. The absorbent article can include a fluid permeable liner and an outer cover. The nonwoven material of the present disclosure can form an absorbent core positioned between the fluid permeable liner and the outer cover. In one embodiment, a surge layer can be placed in between the absorbent core and the fluid permeable liner for directing and channeling fluids into the absorbent core in a fast and efficient manner.

[0173] In one particular embodiment, the nonwoven material of the present disclosure can be incorporated into a feminine hygiene product.

[0174] Referring to Fig. 7, for instance, one particular embodiment of a feminine care absorbent article 200 is shown. More particularly, the article 200 includes a topsheet 226, a baffle 228, and an absorbent member 233 positioned between the topsheet 226 and the baffle 228. The topsheet 226 defines a body-facing surface of the absorbent article 200. The absorbent member 233 is positioned inwardly from the outer periphery of the absorbent article 200 and includes a body-facing side positioned adjacent the topsheet 226 and a garment-facing surface positioned adjacent the baffle 228. Typically, the topsheet 226 and the baffle 228 are joined by adhesive bonding, ultrasonic bonding, or any other suitable joining method known in the art, the sealed edges defining an overall sealed peripheral edge 299 of the article 200 The article 200 may take on various geometries but will generally have opposite lateral sides and longitudinal ends.

[0175] The topsheet 226 helps provide comfort and conformability, and also helps direct bodily exudates away from the body toward the absorbent member 230. Typically, the topsheet 226 and the baffle 228 have peripheral margins 299 that extend outwardly beyond the terminal, peripheral edges of the absorbent member 230, and the extending margins are joined together to partially or entirely, surround or enclose the absorbent core. The topsheet 226 contacts the body of the user and is liquid- permeable. The topsheet 226 may be formed from one or multiple layers of materials. The liquid- permeable topsheet 226 has an outwardly facing surface that may contact the body of the wearer and receive fluids from the body. The topsheet 226 may define an inner region positioned between laterally spaced first and second outer regions. The inner and outer regions may be formed from a single section of material, or from multiple sections. Such multi-section topsheet configurations are known in the art and described in more detail, for instance, in U.S. Patent No. 5,415,640 to Kirby, et al. Whether having one or multiple sections, the topsheet 226 may be made from any liquid-permeable material known in the art. For example, the topsheet 226 can be constructed of any woven or nonwoven material that is easily penetrated by bodily exudates. Examples of suitable materials include rayon, bonded carded webs of polyester, polypropylene, polyethylene, nylon, or other heat- bondable fibers, polyolefins, such as copolymers of polypropylene and polyethylene, linear low-density polyethylene, and aliphatic esters such as polylactic acid. Finely perforated film webs and net material can also be used. A specific example of a suitable topsheet material is a bonded carded web made of polypropylene and polyethylene, such as that used as topsheet stock for KOTEX® pantiliners. U.S. Patent Nos. 4,801 ,494 to Datta, et al. and 4,908,026 to Sukiennik, et al. describe various other topsheet materials that may be used in the present invention. Such materials typically have a basis weight of less than about 100 gsm, and in some embodiments, from about 10 gsm to about 40 gsm.

[0176] The baffle 228 is generally liquid-impermeable and designed to face the inner surface, i.e. , the crotch portion of an undergarment (not shown). The baffle 228 may permit a passage of air or vapor out of the absorbent article 200, while still blocking the passage of liquids. Any liquid-impermeable material may generally be utilized to form the baffle 228. For example, one suitable material that may be utilized is a microporous polymeric film, such as polyethylene or polypropylene. In particular embodiments, a polyethylene film is utilized that has a thickness in the range of about 0.2 mils to about 5.0 mils, and particularly between about 0.5 to about 3.0 mils. A specific example of a baffle material is a polyethylene film such as that used in KOTEX® pantiliners.

[0177] A nonwoven material 233 or an absorbent structure made in accordance with the present disclosure is incorporated into the feminine care absorbent article 200. In particular, the absorbent structure 233 is positioned between the topsheet 226 and the baffle 228 for absorbing and retaining body exudates, including menses.

[0178] The topsheet 226 may be maintained in secured relation with the absorbent structure 230 by bonding all or a portion of the adjacent surfaces to one another. A variety of bonding mechanisms known to one of skill in the art may be utilized to achieve any such secured relation. Examples of such mechanisms include, but are not limited to, the application of adhesives in a variety of patterns between the two adjoining surfaces, entangling at least portions of the adjacent surface of the absorbent with portions of the adjacent surface of the cover, or fusing at least portions of the adjacent surface of the cover to portions of the adjacent surface of the absorbent (e.g., ultrasonically fusing). If desired, the feminine care absorbent article 200 may also include laterally extending wing portions 242 that may be integrally connected to side regions along the intermediate portion of the article. For example, the wing portions 242 may be separately provided members that are subsequently attached or otherwise operatively joined to the intermediate portion of the article. In other configurations, the wing portions may be unitarily formed with one or more components of the article. As representatively shown in FIG. 7, for example, either or both wing portions 242 may be formed from a corresponding, operative extension of the material employed to form the baffle 228. Alternatively, either or both wing portions 242 may be formed from a corresponding, operative extension of the material employed to form the topsheet 226, or formed from a corresponding, operative combination of the topsheet and baffle materials.

[0179] The present disclosure may be better understood with reference to the following examples.

[0180] Example No. 1

[0181] In the example below, various different multi-zone nonwoven materials were produced and tested for strength and toughness. All of the samples below were produced using a foam-forming process. The following multi-zone substrates were produced:

[0182] The superabsorbent material (SAM) was commercially available SXM 5660 manufactured by Evonik. The binder fibers used had a polyethylene / PET sheath / core structure. The crosslinked pulp fiber used was obtained from International Paper. A wet strength agent was incorporated into each of the zones. The wet strength agent was Kymene 920 obtained from Solenis. The first zone contained the wet strength agent in an amount of 0.8% by weight based on the weight of crosslinked pulp fibers present. The second zone contained the wet strength agent in the amount of 0.2% by weight based upon the weight of the crosslinked pulp fibers and the bleached chemithermomechanical pulp fibers present. Each of the above samples were tested for toughness and peak load. The samples were produced in rolls and also fed to a processing line for producing absorbent articles and tested for breaks. The following results were obtained:

[0183] As shown above, samples produced where the intake zone and the transfer zone were made from the same fiber furnish displayed greater strength properties and were easily processed without breaks. In Sample Nos. 11 and 12 above, the fiber composition of the intake and transfer layers were identical, and the basis weights of the intake and transfer layers were also identical. These samples are insensitive to flipping a product manufacturing process (e.g. the intake and transfer layers are reversible). Sample No. 12 displayed better SAM particle retention and better handling.

[0184] Example No. 2 In the example below, various different multi-zone nonwoven materials (or absorbent articles containing the materials) were produced and tested for strength and fluid control properties. Similar to Example No. 1 , all of the absorbent substrate samples were produced using a foam-forming process. The multi-zone substrates were formed from the following furnish:

[0185] Top and Bottom Layer: 20% by weight bicomponent binder fibers, 1 .3 dtex, 6 mm; 50% by weight polyester fibers, 13 dtex, 6 mm; 30% by weight crosslinked pulp fibers

[0186] Middle Layer: 35% by weight SAM, 65% by weight fiber (20% by weight bicomponent binder fibers, 1 .3 dtex, 6 mm; 25% by weight crosslinked pulp fibers; 55% by weight bleached chemithermomechanical pulp fibers)

[0187] Substrates were produced having basis weights from 80 gsm to 200 gsm in increments of 20 gsm.

[0188] The results of the tests are shown graphically in Figures 6 through 12. As shown, the substrates displayed excellent strength and liquid handling properties at lower basis weights.

[0189] From the results of the Retention Capacity Test, the Absorbent Efficiency of each sample was calculated. The Absorbent Efficiency is calculated by dividing the Retention Capacity by the Basis Weight and multiplying by the Thickness. The units are gfiuid(m3 / gmateriai). The following results were obtained:

[0190] As shown above, the absorbent structures displayed excellent Absorbent Efficiency characteristics at low basis weights and thicknesses. At basis weights below 250 gsm and / or below 200 gsm, the abosorbent structures displayed an Absorbent Efficiency of greater than about 0.00025 gf(m3 / gm), such as greater than about 0.00028 gf(m3 / gm), such as greater than about 0.0003 gf(m3 / gm), such as greater than about 0.00035 gf(m3 / gm), such as greater than about 0.0004 gf(m3 / gm), such as greater than about 0.00045 gf(m3 / gm), such as greater than about 0.0005 gf(m3 / gm), and less than about 0.001 gf(m3 / gm).

[0191] These and other modifications and variations to the present invention may be practiced by those of ordinary skill in the art, without departing from the spirit and scope of the present invention, which is more particularly set forth in the appended claims. In addition, it should be understood that aspects of the various embodiments may be interchanged both in whole or in part. Furthermore, those of ordinary skill in the art will appreciate that the foregoing description is by way of example only and is not intended to limit the invention so further described in such appended claims.

Claims

1. What Is Claimed:1 . An absorbent article comprising: a liquid permeable liner; a multi-zone absorbent structure comprising an intake zone facing the liquid permeable liner and an absorbent zone, the intake zone comprising binder fibers and crosslinked pulp fibers, the absorbent zone comprising a superabsorbent material, the absorbent structure having a basis weight of from about 80 gsm to about 250 gsm; and wherein when tested according to the Horizontal Side Compression Test, the absorbent article displays an energy after three cycles of less than about 1000 gTcm, and displays a width recovery of greater than about 70%; and wherein, when tested according to the Intake Test, the absorbent article displays a second intake time of less than about 140 seconds, and displays a rewet of less than about 3.5 g.

2. An absorbent article as defined in claim 1 , wherein the absorbent structure displays a toughness of at least about 2 in*lbf and displays a peak load of at least about 2,300 gf.

3. An absorbent article as defined in claim 1 , wherein when tested according to the Horizontal Side Compression Test, the absorbent article displays an energy after three cycles of less than about 650 gfcm, and displays a width recovery of greater than about 73%.4 An absorbent article as defined in claim 1 , wherein when tested according to the Horizontal Side Compression Test, the absorbent article displays an energy after three cycles of less than about 600 gf cm, and displays a width recovery of greater than about 73%.

5. An absorbent article as defined in claim 1 , wherein, when tested according to the Intake Test, the absorbent article displays a second intake time of less than about 100 seconds, and displays a rewet of less than about 3 g.

6. An absorbent article as defined in claim 1 , wherein, when tested according to the Intake Test, the absorbent article displays a second intake time of less than about 90 seconds, and displays a rewet of less than about 2.8 g.7 An absorbent article as defined in claim 1 , wherein, when tested according to the Intake Test, the absorbent article displays a second intake time of less than about 80 seconds, and displays a rewet of less than about 2.5 g.

8. An absorbent article as defined in claim 1 , wherein the absorbent structure displays a toughness of at least about 5 in*lbf and displays a peak load of at least about 3,500 gf.

9. An absorbent article as defined in claim 1 , wherein the absorbent structure further comprises a transfer zone, the absorbent zone being positioned between the intake zone and the transfer zone, and wherein the intake zone, the absorbent zone, and the transfer zone all containfibers, and wherein at least some of the fibers of the intake zone are mixed with at least some of the fibers of the absorbent zone, and wherein at least some of the fibers of the absorbent zone are mixed with at least some of the absorbent fibers of the transfer zone.

10. An absorbent article as defined in claim 9, wherein the intake zone has a basis weight of from about 10 gsm to about 85 gsm, the absorbent zone has a basis weight of from about 60 gsm to about 180 gsm, and the transfer zone has a basis weight of from about 10 gsm to about 40 gsm.

11. An absorbent article as defined in claim 9, wherein the intake zone has a basis weight of from about 55 gsm to about 80 gsm, the absorbent zone has a basis weight of from about 80 gsm to about 155 gsm, and the transfer zone has a basis weight of from about 12 gsm to about 30 gsm.

12. An absorbent article as defined in claim 9, wherein the intake zone and the transfer zone both contain binder fibers, synthetic polymer fibers, and crosslinked pulp fibers.

13. An absorbent article as defined in claim 12, wherein the intake zone and the transfer zone contain the binder fibers in an amount from about 10% by weight to about 40% by weight, contain synthetic polymer fibers in an amount from about 40% by weight to about 60% by weight, and contain the crosslinked pulp fibers in an amount from about 20% by weight to about 40% by weight.

14. An absorbent article as defined in claim 1 , wherein the absorbent zone contains binder fibers, crosslinked pulp fibers, bleached chemithermomechanical pulp fibers, and a superabsorbent material.

15. An absorbent article as defined in claim 14, wherein the absorbent zone contains the binder fibers in an amount from about 10% to about 30% by weight based on the total weight of fibers present in the zone, contains crosslinked pulp fibers in an amount from about 15% by weight to about 35% by weight based upon the total weight of fibers contained in the zone, and contains bleached chemithermomechanical pulp in an amount from about 45% by weight to about 65% by weight based upon the total fibers present in the zone, and wherein the absorbent zone contains the superabsorbent material in an amount from about 20% by weight to about 45% by weight.

16. An absorbent article as defined in claim 9, wherein the intake zone and the transfer zone contain the same fibers in the same weight percentages..

17. An absorbent article as defined in claim 1 , wherein the absorbent structure has a thickness of less than about 3 mm and displays an Absorbent Efficiency of greater than about 0.00025 gf(m3 / gm).

18. An absorbent article as defined in claim 1 , wherein the absorbent structure has a thickness of less than about 2.8 mm and displays an Absorbent Efficiency of greater than about 0.00035 gf(m3 / gm).

19. An absorbent article as defined in claim 1 , wherein the absorbent structure has been foam formed.

20. An absorbent article comprising: a liquid permeable liner; a multi-zone absorbent structure comprising:(a) an intake zone containing from about 10% by weight to about 40% by weight binder fibers, containing from about 40% by weight to about 60% by weight synthetic polymer fibers, and containing between about 20% by weight to about 40% by weight crosslinked pulp fibers;(b) an absorbent zone comprising a plurality of fibers combined with a superabsorbent material, the plurality of fibers including from about 10% by weight to about 30% by weight binder fibers based upon the total fibers present, between about 15% by weight to about 35% by weight crosslinked pulp fibers based upon the total fibers present, and between about 45% by weight to about 65% by weight bleached chemithermomechanical pulp fibers based upon the total fibers present, the superabsorbent material comprising about 20% by weight to about 45% by weight of the absorbent zone; and(c) a transfer zone, the absorbent zone being disposed between the intake zone and the transfer zone, the transfer zone containing about 10% by weight to about 40% by weight binder fibers, containing from about 40% by weight to about 60% by weight synthetic polymer fibers, and containing from about 20% by weight to about 40% by weight crosslinked pulp fibers.21 . An absorbent article as defined in claim 20, wherein the absorbent structure displays a toughness of at least 5 in*lbf and displays a peak load of at least about 3,000 gf; wherein when tested according to the Horizontal Side Compression Test, the absorbent article displays an energy after three cycles of less than about 650 gf'cm, and displays a width recovery of greater than about 73%; and wherein, when tested according to the Intake Test, the absorbent article displays a second intake time of less than about 90 seconds, and displays a rewet of less than about 2.8 g.

22. An absorbent article as defined in claim 21 , wherein the absorbent structure has a basis weight of from about 120 gsm to about 180 gsm.

23. An absorbent article as defined in claim 20, wherein the absorbent article comprises a feminine hygiene product.

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