Adhesive absorbent article having front and crotch channels

Abstract

An adhesive absorbent article 20 is provided that includes a crotchway 26 having a crotchway bond strength and a frontway 56 that has no bond or a frontway bond strength that is weaker than the crotchway bond strength. The frontway at least partially overlaps a landing zone 44 on which the rear ear belt 42 can releasably fasten. During use, the frontway can delaminate to reduce stress on the landing zone and avoid accidental disengagement of the belt 42.

Description

Technical Field

[0001] This invention relates to personal hygiene absorbent articles for absorbing bodily excretions such as urine and feces. Background Technology

[0002] Absorbent products for personal hygiene, such as diapers, are designed to absorb and contain bodily waste, especially large amounts of urine. Diapers generally fall into two categories: adhesive-backed and trouser-style. Adhesive-backed diapers include a pair of fastening straps on the back of the garment, which are fastened to the landing area material at the front to form a closed garment. The garment is typically applied to the wearer by first laying it down and opening it so that its inside is facing up. The wearer then positions their buttocks toward the center of that inside of the garment. The front half and lateral sides of the garment are then folded over the wearer's legs and crotch, and the garment is closed around the wearer's legs and waist by fastening the straps to the landing area material. Trouser-style diapers, on the other hand, have pre-sealed side seams and are worn like underwear by sliding along the wearer's legs through pre-formed leg openings to the crotch.

[0003] Absorbent products such as diapers typically consist of a liquid-permeable topsheet facing the wearer, a liquid-impermeable bottomsheet facing the clothing, and an absorbent core for absorbing fluid outflow between these two layers. The absorbent core typically comprises layers of absorbent material sandwiched between an upper base layer and a lower base layer. The lower and upper base layers are typically sealed along the longitudinal edges of the core and may have openings or seals at their front and rear edges. The upper and lower base layers are typically low-basic-weight nonwoven fabrics or thin sheets of paper and may be collectively referred to as the core wrapper.

[0004] As is known in the art, absorbent materials typically contain superabsorbent polymers (SAPs). SAPs are usually in small particle form and can be blended with cellulose fibers. SAPs typically comprise 40% to 70% of the absorbent material by weight, with the remainder being cellulose fibers. Recently, so-called wood pulp-free or non-permeable felt-free absorbent cores (where the absorbent material does not contain cellulose fibers) have been commercially available. In these non-permeable felt-free cores, SAP particles can be encapsulated in pockets, see, for example, US5,433,715 (Tanzer et al.), WO2012 / 052172 (Van Malderen); or secured by a fiber network of adhesive fibers, see, for example, US2008 / 312617 (Hundorf et al.).

[0005] Absorbent cores comprising channels in the absorbent layer that are substantially free of absorbent material have been proposed. These channels can help guide fluid to longer areas of the absorbent core in a more efficient manner than diffusion, or help the core conform to a desired shape during use. Various channel configurations have been proposed in the prior art. Channels formed without an adhesive portion between the upper and lower substrate layers disappear rapidly as the absorbent material swells and fills the channel, or even earlier due to the wearer's movement. Adhesive channels have also been proposed, in which the upper substrate layer of the core is bonded to the lower substrate layer of the core through the channel. Adhesive permanent channels can remain in place even after the absorbent core has absorbed a significant amount of fluid. The upper and lower substrate layers can be bonded in the channel using known bonding techniques such as adhesive bonding, mechanical bonding, thermal bonding, or ultrasonic bonding. Examples of such bonded channels are disclosed, for example, in WO2012 / 170778A1, WO2012 / 170779A1 (both inventors are Rosati et al.), and WO2014 / 93129 (Roe et al.). The advantages of such bonded channels include improved fit during use, less core sagging, and better fluid distribution. Channels with temporary adhesive portions that gradually open during use to release more space for SAP swelling have also been proposed, such as those disclosed in WO2014 / 200794 (Bianchi et al.). These temporary channels advantageously release more volume for the absorbent material to swell as the absorbent core is loaded, while maintaining the beneficial effect of permanent channels under lower loads. WO2019 / 083767A1 (Bianchi) discloses absorbent articles comprising channels located at different locations within the absorbent core and having different adhesive strengths to allow for gradual and controlled opening of the channels.

[0006] This invention relates to absorbent articles comprising a crotch channel and a front channel in their absorbent core. It has been found that a front channel extending relatively close to the front edge of the article provides the following advantages: keeping the diaper close to the wearer's front when the strap is not optimally fastened to the landing area, and preventing the front edge of the article from flipping or folding. It has also been found that this front channel reduces the core protrusion at the front of the article and maintains sufficient longitudinal stiffness when the absorbent material swells. However, in this configuration where the front channel is positioned close to the front edge of the absorbent article, the front channel at least partially overlaps with the landing area, where the fastening strap is fastened during use. It has been found that as the core swells, the three-dimensional peak and valley profile conforms to the shape of the front channel, with the landing area material deforming in a similar manner. When the absorbent material swells to relatively high loads, this induces stress on the landing area, which can thus inadvertently release the fastening strap. This invention addresses these problems. Summary of the Invention

[0007] The invention relates in a first aspect to an adhesive absorbent article, and in a second aspect to a method for preparing such an article, as indicated in the claims. The absorbent core of the article includes an absorbent material layer disposed between an upper substrate layer and a lower substrate layer. The absorbent material layer includes at least one crotch channel primarily disposed in the crotch area of ​​the article and at least one front channel primarily disposed in the front area of ​​the article, the front channel at least partially overlapping the landing area.

[0008] According to the present invention, when the upper and lower base layers are bonded to each other through the crotch channel, the front channel is less firmly bonded or even substantially unbonded, such that when the absorbent material swells after absorbing the fluid, the absorbent material can more easily cause the upper base layer to delaminate from the lower base layer in the front channel.

[0009] This invention significantly reduces the stress caused by the swollen absorbent material in the landing zone where the front channel exists, thereby mitigating the problem of the aforementioned band accidentally loosening from the landing zone. On the other hand, the crotch channel has a higher crotch channel bond strength than the front channel. Therefore, the crotch channels can perform their functions, such as distributing fluid in the longitudinal direction of the absorbent layer over a large absorbent load range.

[0010] Further advantageous aspects of the invention are disclosed in the following description and claims. Specifically, the crotch channel and the front channel may each be provided as a pair of channels symmetrically arranged with respect to the longitudinal axis of the article. The front channel may be separated from the crotch channel by a separation zone containing absorbent material. Optionally, the front channel and the crotch channel do not reach any edge of the absorbent material layer and are therefore completely contained within the absorbent material layer. The absorbent material may be a mixture of cellulose fibers and SAP particles, or alternatively, the absorbent material may consist substantially of SAP particles without cellulose fibers. This aspect and various other aspects of the invention are described in the following description and appended claims. Attached Figure Description

[0011] Figure 1 A top view of an exemplary adhesive diaper that has been flattened out, facing the wearer, with some layers partially removed;

[0012] Figure 2 It shows Figure 1 A partial exploded view of an adhesive diaper;

[0013] Figure 3 It shows Figure 1 A schematic transverse section of a diaper in the crotch passage area;

[0014] Figure 4a It shows Figure 1 A schematic transverse section of a diaper in the area of ​​the front channel, where the front channel is bonded;

[0015] Figure 4b It shows Figure 1 An alternative schematic transverse section of the diaper in the area of ​​the front channel, wherein the front channel is not bonded;

[0016] Figure 5 This is a top view of an exemplary absorbent core shown separately in the previous figures, with the upper base layer of the core partially removed;

[0017] Figure 6 This is a top view of an alternative core with a shaped absorbent layer;

[0018] Figure 7 This is a top view of an alternative core with a straight channel;

[0019] Figure 8 It is a top view of an alternative core having an X-shaped crotch passage;

[0020] Figures 9 to 12 This demonstrates how to perform the static peel force time test, which is further described in this paper.

[0021] For ease of discussion, the absorbent core and articles of the invention will be discussed with reference to these figures and the reference numerals in the figures; however, unless specifically indicated, these are not intended to limit the scope of the claims.

[0022] As used herein, the terms “comprising” or “including” are open-ended terms; each specifies the presence of a subsequent feature, such as a component, but does not exclude the presence of other features, such as elements, steps, or components, known in the art or disclosed herein. These terms based on the verb “comprising” should be interpreted to cover the narrower term “substantially constitutes”, which excludes any unmentioned elements, steps, or components that significantly affect the manner in which said feature performs its function; and the broader term “consisting of”, which excludes any unspecified elements, steps, or components. Any preferred or exemplary embodiments described below do not limit the scope of the claims unless expressly stated otherwise. The words “usually,” “often,” “preferably,” “advantageously,” “specifically,” “optionally,” etc., also define the feature, and they are not intended to limit the scope of the claims unless expressly stated otherwise. Detailed Implementation

[0023] General description of absorbent article 20

[0024] An exemplary absorbent article according to the invention, in the form of an adhesive baby diaper 20, is shown in Figure 1 See Figure 4. Figure 1 This is a top plan view of an exemplary diaper in a flat position, with multiple portions of the structure cut off to show the diaper's construction more clearly. Figure 2As an exploded view, it shows Figure 1 The different layers of the diaper. Figure 3 Figure 4 shows the routes respectively. Figure 1 The diagram shows cross-sectional views of diaper 20 taken along lines 3-3 and 4-4. Diaper 20 is shown for illustrative purposes only and is not restrictive unless specifically stated otherwise. In the following description, the terms "diaper" and "absorbent article" are used interchangeably.

[0025] like Figure 1 As shown, the absorbent article 20 includes a front edge 10, a rear edge 12, and two longitudinally extending side (lateral) edges 13 and 14. The front edge 10 is the edge of the article intended to be positioned towards the front of the user when worn, and the rear edge 12 is the opposite edge. When the article is viewed from the wearer-facing side in a flat configuration, the absorbent article is hypothetically divided by a longitudinal axis 80 that extends longitudinally from the middle of the front edge 10 to the middle of the rear edge 12, dividing the article into two substantially symmetrical halves relative to this axis, as shown. Figure 1 As exemplarily shown. If some portions of an article are under tension due to elastic components, the article can typically be flattened by using clamps along the periphery of the article and / or the adhesive surface, allowing the article to be pulled taut to become substantially flat. Unless otherwise specified, the dimensions and areas disclosed herein apply to absorbent articles and absorbent cores in this flattened configuration.

[0026] The article has a length L measured along the longitudinal axis 80 from the middle of the front edge 12 to the middle of the rear edge 10. The absorbent article may also be hypothetically divided by a transverse axis 90. The transverse axis 90 is perpendicular to the longitudinal axis 80 and intersects the longitudinal axis at half the length L. The intersection of the longitudinal axis 80 and the transverse axis 90 is defined herein as the center point C of the article. The article may further hypothetically be divided along the longitudinal axis into three zones of equal length (one-third of L): a front zone 62 extending one-third of L from the front edge 10 toward the crotch area, a crotch area 63 located in the middle one-third of the diaper, and a rear zone 64 extending the remaining one-third of L from the crotch area of ​​the article toward the rear edge 12. When the article is in this flat state, all three zones have equal lengths measured along the longitudinal axis. The front zone, crotch area, rear zone, and the longitudinal and transverse axes are hypothetically defined herein, meaning they are not actually present in a real diaper, but are used to describe the positions of various components of the invention relative to each other and the diaper.

[0027] The absorbent article 20 includes a liquid-permeable top sheet 24, a liquid-impermeable bottom sheet 25, and an absorbent core 28 located between the top sheet and the bottom sheet. The absorbent core includes absorbent material 60 sandwiched between an upper base layer 16 and a lower base layer 16'. The upper and lower base layers together are referred to as the core wrapper. Viewed from a plane formed by the longitudinal axis and the transverse axis, the absorbent material layer 60 has a rectangular or shaped profile. The absorbent material layer 60 includes at least one crotch channel 26 and at least one front channel 56. The crotch channel 26 is mainly disposed in the crotch area of ​​the article (which may extend into the front and / or rear areas of the article), and the front channel 56 is mainly disposed in the front area of ​​the article. The crotch channel 56 includes an adhesive portion 27 between the upper and lower base layers, while the front channel has no adhesive portion or only an adhesive portion 57 weaker than that of the crotch channel. The front channel and the crotch channel, as well as their respective adhesive portions, will be discussed in more detail below. The front channel and the crotch channel are each preferably configured as a pair of channels symmetrically arranged with respect to the longitudinal axis. A pair of channels may or may not be connected to each other along a longitudinal axis, and the pair may form, for example, a U-shape, a V-shape, or an X-shape. As used herein, unless otherwise specifically indicated, the term “channel” or “at least one channel” means “one or more channels, specifically at least one pair of channels”.

[0028] The product of this invention is an adhesive product, such as in Figure 1 As exemplarily shown in a diaper, the adhesive article includes a pair of fastening straps 42 disposed on the rear area of ​​the article and a landing area 44 disposed on the front area of ​​the article. The landing area is typically a discrete piece of material (typically nonwoven) attached to the outer surface of the substrate. If such a layer is present, the landing area may also be integral with the nonwoven outer cover of the substrate; however, this would increase the overall price of the substrate compared to a discrete landing area.

[0029] The wearer-facing side of the garment is primarily formed by the top piece 24. Detergent (not shown) is typically present directly on the top piece in longitudinally extending strips. Other typical diaper components are also shown in these figures, such as the elasticated liner hoop 32 (also called the outer hoop) and the upright blocking leg hoop 34 (also called the inner hoop, which is also typically elastic). For clarity, only one elastic strand 33, 35 is shown for each type of hoop, but typically each hoop may include 1 to 4 elastic strands.

[0030] The absorbent article may also include one or more collection layers and / or dispensing layers 52 between the top sheet and the absorbent core. The collection layer 52 may be disposed directly beneath the top sheet, wherein a dispensing layer (not shown) optionally exists between the collection layer 52 and the absorbent core 28. Any collection layer or dispensing layer may also optionally include channels (not shown) free of collection or dispensing material. Different components of the article are typically attached to adjacent components by any known means, such as adhesive bonding; for example, the top sheet may be attached to the collection layer, and the collection layer may be attached to the upper substrate layer of the absorbent core by spiral adhesives or trough coatings known in the art. For simplicity, these attachments are not shown in the figures.

[0031] These and other components will be discussed in more detail below. Absorbent products may also include other typical components not shown in the figures, such as a rear elastic waist structure, a front elastic waist structure, a transverse barrier band, a wetting indicator mark located between the substrate and the absorbent core that changes color upon contact with urine, etc.

[0032] Fastening systems 42, 44

[0033] The absorbent article includes a pair of fastening straps 42 on the rear region of the article, which are fastenable to a landing area 44 on the front region of the article to form a closed article with a waist opening and two leg openings. This fastening system provides lateral tension around the absorbent article to hold it around the wearer's waist. The fastening straps 42 can be attached to stretchable back flaps 40 disposed on each side of the rear region of the article. The back flaps 40 can be attached to a base structure of the article, as known in the art, for example as disclosed in WO2006 / 138,725A2 (Lam et al.).

[0034] The fastening system can be based on any typical construction known in the art. Fastening systems typically include interlocking fasteners, such as those known in hook-and-loop systems. The fastening band 42 typically includes a "hook" portion 42a, where the "loop" is part of the landing area material, which typically comprises a nonwoven material with suitably shaped fibers. Other known fastening systems that include interlocking fasteners are tabs and slots, buckles, buttons, latches, and / or hermaphroditic fastening components. Any known fastening device is generally acceptable. The fastening system is preferably re-tightenable, allowing the user to readjust the band's tightness. The fasteners are typically releasably attached to the landing area.

[0035] Landing zone 44 is provided on the front waist area of ​​the article, wherein the fastening band 42 engages with the landing zone when the article is worn on the wearer. Although the landing zone is typically a discrete single material, it is not excluded that the landing zone may include, for example, two separate portions provided on each side of the longitudinal axis and separated by gaps to engage the left and right fastening bands respectively.

[0036] Some exemplary fastening systems are disclosed in US3,848,594, US4,662,875, US4,846,815, US4,894,060, US4,946,527, US5,151,092, and US5,221,274 (Buell). An exemplary interlocking fastening system is disclosed in US6,432,098. Fastening systems may also provide means for retaining articles in a disposal configuration, such as those disclosed in US4,963,140 (Robertson et al.).

[0037] General description of absorber core 28

[0038] According to the first exemplary absorber core 28 of the present invention, Figure 5 Zhongyu Figure 1 The remaining parts of the product 20 shown are presented separately. The location of the landing area 44 is... Figure 5 Other Figures 6 to 8 The text is indicated by dashed lines. As used herein, the term "absorbent core" or "core" refers to a component of an absorbent article comprising a layer 60 of absorbent material sandwiched between an upper substrate layer 16 and a lower substrate layer 16', wherein the upper and lower substrate layers together are referred to as the core envelope. As used herein, the term "absorbent core" does not include a top sheet, bottom sheet, or dispensing / collecting layer. The absorbent core typically has a majority of the absorbent capacity of all components of the absorbent article and comprises all or at least a majority of the superabsorbent polymer (SAP) in the article. Therefore, the core typically consists essentially of or is composed of the core envelope, absorbent material, and optionally an adhesive. The terms "glue" and "adhesive" are used interchangeably. The absorbent material may consist of a blend of SAP particles and cellulose fibers, but the invention is also applicable to other absorbent materials, for example, consisting of 100% SAP particles and / or containing no cellulose fibers. The terms "absorbent core" and "core" are used interchangeably herein.

[0039] The absorbent core can typically be thin and conformable, allowing it to be placed on flat and curved surfaces, for example, on the curved surface of a rotating drum during its fabrication. Figure 5 It shows Figure 1The top view of the absorbent core of the article shown in Figure 4. An upper substrate layer 16 forms the top side of the core, and a lower substrate layer 16' forms the bottom side of the absorbent core. The upper and lower substrate layers can be formed from two separate substrates, but can also have a single substrate forming both the upper and lower substrate layers of the core wrapper. The absorbent core typically includes a front edge 280, a rear edge 282, and two longitudinally extending side edges 284, 286 extending between the front and rear edges. The front edge of the core 280 is the edge toward or intended to be toward the front edge 10 of the absorbent article. Typically, the absorbent material can advantageously be distributed in a slightly higher amount toward the crotch and front areas than toward the rear areas, since higher absorbency is typically required toward the front half of the article. Typically, the front edge 280 and the rear edge 282 are shorter than the longitudinally extending side edges 284, 286. The upper substrate layer 16 of the core wrapper is optionally more hydrophilic than the lower substrate layer 16'.

[0040] The absorbent material can also be formed in the cross-direction. In an absorbent core comprising a pair of crotch channels, the basis weight of the absorbent material can be shaped such that the basis weight of the absorbent material between the crotch channels differs from the basis weight of the absorbent material between the corresponding longitudinal edges of each channel and the core. Depending on the longitudinal position considered, this basis weight can be higher or lower, or both, as taught in WO2017 / 189150 A1 (Bianchi et al.). As indicated in this application, for an absorbent core including a pair of crotch channels, a central absorbent region comprising absorbent material and disposed between the first crotch channel and the second crotch channel, and a first lateral absorbent region and a second lateral absorbent region respectively disposed outwardly on each side of the crotch channel, are characterized in that, for at least a first transverse segment of a core having a first length of at least 10 mm in the longitudinal direction, the basis weight of the absorbent material in the central absorbent region is higher than the basis weight of the absorbent material in each of the lateral absorbent regions; and for at least a second transverse segment of a core having a second length of at least 10 mm in the longitudinal direction, the basis weight of the absorbent material in the central absorbent region is lower than the basis weight of the absorbent material in each of the lateral absorbent regions.

[0041] On the other hand, it is advantageous that the basis weight of the absorbent material remains constant in the transverse direction in the region where the front channels exist (e.g., for a pair of front channels, this means that the basis weight of the absorbent material is the same between the front channels and between the longitudinal edges of each channel and the corresponding absorbent layer). Maintaining a constant basis weight in the front channel region helps prevent the channels from delaminating under swelling pressure before producing an overly rigid three-dimensional structure that could affect the functionality of the band. However, the basis weight of the absorbent material can also be shaped in the transverse direction across the machine in the region where the front channels are located.

[0042] The total area occupied by the absorbent core is defined by the core wrapping and is generally rectangular, with a core width W' in the transverse direction and a core length L' in the longitudinal direction (as measured from edge to edge), including the area of ​​the core wrapping that does not encapsulate absorbent material, specifically located at the front seal 280' and rear seal 282' when present. The core wrapping is typically sealed longitudinally at its rear and front edges and optionally transversely. If the core is not rectangular, the maximum dimensions measured in the transverse and longitudinal directions can be used to report the width and length of the core, respectively. The width and length of the core may vary depending on the intended use. For baby diapers and toddler diapers, the width W' may, for example, range from 40 mm to 200 mm, and the length L may range from 100 mm to 600 mm. Adult incontinence products may have higher maximum dimensions. The absorbent core may be symmetrical with respect to the longitudinal axis 80. When the core is incorporated into an article, the longitudinal axis of the core generally overlaps with the longitudinal axis of the absorbent article, and therefore these two longitudinal axes are named with the same reference numeral 80 in the figures.

[0043] The absorbent material can be any conventional absorbent material used in absorbent articles. The absorbent material can be a blend of cellulose fibers and superabsorbent polymer (SAP) particles, also known as absorbent gelling material (AGM), see, for example, US 5,151,092 (Buell). The absorbent material may specifically contain 30% to 75% by weight of SAP particles, specifically 40% to 70% by weight of SAP particles, or 45% to 65% by weight of SAP particles relative to the total weight of the absorbent material. The remainder of the absorbent material is typically cellulose fibers. Thus, the absorbent material may contain 25% to 70% by weight of cellulose fibers. Synthetic fibers may also be included in the absorbent core, but are not generally considered absorbent materials. The absorbent material may also contain higher amounts of SAP, up to 75%, 80%, or more by weight of the absorbent material, blended with cellulose or other fibers. As is known in the art, the absorbent core may also consist substantially of SAP as the absorbent material without cellulose fibers (so-called "felt-free" core). For example, WO2008 / 155699 (Hundorf) discloses an absorbent core with a patterned layer of SAP, the patterned layer of which is fixed by depositing a web of fibrous thermoplastic adhesive material onto the SAP layer.

[0044] Suitable SAPs can be any water-insoluble, water-swellable polymer capable of absorbing large volumes of fluid, as is known in the art. The term “superabsorbent polymer” refers herein to absorbent materials that are typically cross-linked polymeric materials capable of absorbing at least 10 times their own weight in a 0.9% saline solution containing water when measured using a centrifugal retention capacity (CRC) test (EDANA method WSP 241.2.R3(12)). Specifically, the SAP may have a CRC value of more than 20 g / g, or more than 24 g / g, or 20 g / g to 50 g / g, or 20 g / g to 40 g / g, or 24 g / g to 30 g / g.

[0045] The absorbent material layer 60 can be as follows: Figure 5 The shape shown is roughly rectangular, but other shapes are also possible. The absorbent layer can be shaped such that the longitudinal edges 284, 286 of the core have segments in the crotch area that taper relative to the front and rear areas, as shown. Figure 6 The shaped absorption layer 60' is shown in the figure. Figure 7 The diagram shows an alternatively shaped absorbent layer with a front region larger than the rear region. Small-sized baby diapers may also include notches on the front edge of the absorbent material layer to accommodate the presence of umbilical cord remnants.

[0046] The absorbent core is not limited to a specific thickness / caliper. Typically, the thickness of the core (dry, i.e., before use), measured at the center point (C) where the longitudinal and transverse axes of the article intersect, can range from 2.0 mm to 10.0 mm, specifically from 3.0 mm to 7.0 mm, as measured at 2.07 kPa (0.30 psi) with a flat, round support with a diameter of 17.0 mm (±0.2 mm).

[0047] The absorbent material can be deposited on the layer using either the upper or lower substrate as the deposition substrate, and then another layer can be applied or folded over the thus deposited absorbent layer. Alternatively, the absorbent material can be deposited as a first absorbent layer and a second absorbent layer on the upper substrate 16 and the lower substrate 16', respectively, and then the two absorbent layers are brought into face-to-face contact and sandwiched together to form a monolithic layer. This configuration is used, for example, in certain absorbent cores without breathable felt, such as those disclosed in WO2008 / 155699 (Hundorf et al.).

[0048] The absorbent cores of the present invention are not limited to any particular process for their preparation, and can be made more conventionally by air-forming a mixture of cellulose fibers and superabsorbent particles onto a conventional air-forming rotary drum with protrusions matched to the shape of the desired channels, such that substantially no absorbent material is deposited in these regions. For improved rotary drums with protrusions to create regions with different basis weights, see, for example, WO2004 / 011,723, Venturino et al. The shape of the protrusions can be configured to suit the preparation of any desired channel shape.

[0049] Crotch passage 26 and front passage 56

[0050] The absorbent core 28 includes at least one crotch channel 26 and at least one front channel 56 within the absorbent material layer 60. The channels are areas substantially free of absorbent material. "Substantially free" means that trace amounts of absorbent material may be present due to unintentional contamination of the channels caused by the high-speed manufacturing process. Unless otherwise explicitly stated, the singular form of the word "channel" as used herein refers to "one or more, specifically at least one pair of channels," and it should be understood that a pair of channels will include one channel on one side of the longitudinal axis and another symmetrically positioned on the opposite side of the longitudinal axis.

[0051] The crotch channel 26 is primarily located in the crotch area 63 of the article. The crotch channel may advantageously extend into the front area 62 and rear area 64 of the article, or at least into the front area, or at least into the rear area. These longitudinally extending channels are considered to provide better wet fit of the absorbent article and efficient utilization of the absorbent material. "Primarily located in the crotch area" means that the length of the crotch channel in the crotch area is greater than in the front or rear area of ​​the article. All lengths referred to herein are measured by projection onto the longitudinal axis 80 (or any other imaginary line parallel to the longitudinal axis). At least 40% of the length of the crotch channel may be located in the crotch area, specifically at least 50% of the length of the crotch channel. For example, the crotch channel may be configured such that at least 50% of its length is located in the crotch area, and 25% or less in the rear and front areas, respectively.

[0052] The front channel 56 is primarily present in the front region 62 of the article. "Primarily present" means that at least 50% of the length of the front channel is in the front region of the article, specifically at least 60% and at most 100% (100% of the front channel is completely present in the front region and does not extend into the crotch region). The front channel 56 at least partially overlaps with the landing area 44 in the vertical direction. According to the invention, the front channel extends relatively far toward the front edge of the article, such that the front channel at least partially overlaps with the landing area 44 (in the vertical direction).

[0053] The sum of the projections of all channels in the absorber core onto the longitudinal axis equals the sum of the lengths of all channels present in the core; however, in cases where two channels are positioned at overlapping locations on the longitudinal axis, no overlap is double-counted. For example, in Figure 5 In the core, the cumulative length of the channels is L56 + L26 (the length of the crotch channel plus the length of the front channel). The cumulative projected length of all channels in the core divided by the core length L' and expressed as a percentage is advantageously between 30% and 95%, preferably between 50% and 90%, and specifically between 60% and 90%.

[0054] According to the present invention, the crotch passage 26 includes an adhesive portion 27 between the upper base layer 16 and the lower base layer 16' of the core wrapper, for example as... Figure 3 As shown. The adhesive portion 27 provides structural integrity of the crotch channel in both dry and wet states. Any known bonding technique known in the art can be used to provide this adhesive portion, particularly selected from adhesive bonding, thermal bonding, mechanical bonding, ultrasonic bonding, or any combination thereof. The core adhesive (not shown) can be applied, for example, typically by slot glue application or any other method, at least in the channel regions on the upper and / or lower substrate layers of the core wrapper, and then pressure is applied in the channel regions to provide good adhesive bonding in these regions while the adhesive is still in its open state (for hot melt adhesives). Exemplary patent disclosures of such adhesive bonding processes can be found in breathable felt or absorbent cores without breathable felt in WO2012 / 170,798A1 (Jackels et al.), EP2,905,000 (Jackels et al.), and EP2,905,001 (Armstrong-Ostle et al.).

[0055] Other bonding methods, such as thermal bonding, mechanical bonding, and ultrasonic bonding, can also be used as supplementary or alternative bonding. For example, in the crotch passage, adhesive bonding can be strengthened by thermal bonding, mechanical bonding, or ultrasonic bonding. Such thermal bonding, mechanical bonding, or ultrasonic bonding can be applied to the passage area through the outside of the core wrapping, see, for example, WO95 / 11652 (Tanzer et al.), which discloses auxiliary bonding including water-resistant adhesives or thermal bonding portions.

[0056] Typically, the crotch channel adhesive portion 27 can have the same profile and shape as the channel 26 containing the adhesive portion but without absorbent material, wherein the adhesive portion is slightly smaller to allow for tolerance margins (e.g., a difference of a few mm), as some deviation from optimal registration may occur during high-speed processes. Compared to adhesive portions located in areas containing a non-negligible amount of absorbent material, it is desirable that the channel adhesive portions 27 can be fabricated more efficiently and effectively (if they are located in macroscopic areas without absorbent material (excluding, of course, accidental contamination)). Typical channel widths range from 2 mm to 20 mm, specifically from 4 mm to 12 mm.

[0057] The absorbent core also includes at least one front channel 56, wherein the adhesion between the upper base layer 16 and the lower base layer 16' of the core wrapper is not as strong as that of the crotch channel. These two layers may also not have a significant adhesive portion extending through the front channel. An unbonded channel can be obtained, for example, by not providing an adhesive, or, if an adhesive is present, by not intentionally pressing the base layers together while the adhesive is still tacky, or by not providing any other bonding method in the region of the front channel, such that the top and bottom sides of the core wrapper in these regions will not adhere to each other. This is illustrated, for example, with respect to the front channel 56'. Figure 4b middle.

[0058] These front channels, with little or no adhesive, provide initial rapid fluid distribution in the front region of the core in which they are located. However, these front channels are not as permanent as the crotch channels, and once the absorbent layer absorbs fluid and swells, the upper and lower base layers in these front channels can delaminate due to the swelling pressure of the absorbent material, and thus immediately or gradually release the additional volume that can be filled by the expanding absorbent material.

[0059] Non-permanent bonding can be provided by an inner core adhesive (also known as an auxiliary adhesive), which is typically present on the inner surface of the upper and / or lower substrate layers forming the core package. Such inner core adhesives are commonly used to partially fix the absorbent material within the core package. The inner core adhesive is typically applied extensively on at least one side of the core package by grooving in longitudinal strips or spiraling in a manner known in the art. In some cores without a breathable felt, the SAP particles are also secured using an additional network of adhesive fibers. Therefore, in cases where adhesive is present within the core package, it may be difficult or less easy to avoid applying any adhesive in relatively narrow areas corresponding to the deposition region of the anterior channel. However, if the adhesive is provided at a relatively low basis weight, and / or if no pressure or only minimal pressure is applied between the two sides of the core package during core preparation (in these areas), these adhesives will provide no channel bonding or only weak bonding. Hot melt adhesives typically cool within seconds and lose their adhesive properties after this open time. This means that if no pressure is applied or only minimal pressure is applied directly to the channel area after application, auxiliary adhesives or fiber network hot melt adhesives will produce no bond or only a much weaker bond compared to if stronger pressure is applied, for example, milliseconds after application. Alternatively or additionally, more of the same or different adhesives (the supplementary adhesives herein) may be applied to the area of ​​the crotch channel, but not to the anterior channel, thereby providing a stronger bond in the crotch channel compared to the anterior channel. Alternatively or additionally, in addition to either of the structural adhesives previously shown in both types of channels, supplementary adhesives such as thermal bonding or ultrasonic bonding may be used.

[0060] In summary, a relatively strong adhesive is intentionally provided between the upper and lower layers of the core for the crotch channel, for example, by using a first bonding method specifically for these channels, such as an inner core adhesive, and additional bonding methods such as additional pressure application, supplementary adhesive, thermal bonding, ultrasonic bonding, or mechanical bonding (such as embossing). On the other hand, the front channel, such as... Figure 4a The diagram shows a weaker adhesive portion 57 or as shown. Figure 4b The diagram shows no adhesive portions. If a weaker adhesive portion 57 is present in the front channel, this adhesive portion may, for example, include the same first adhesive method as the crotch channel, but not the additional adhesive method of the crotch channel adhesive portion. Therefore, if the front channel adhesive portion 57 is present, the front channel adhesive portion will be more prone to delamination than the crotch channel adhesive portion 27. During use, the front channel adhesive portion 57 will therefore delaminate faster than the crotch channel adhesive portion 27. The crotch channel adhesive portions can even be substantially permanent, such that they generally do not release during prolonged wear of the article.

[0061] The strength of the bond between the upper and lower base layers in the channel can be characterized by its static peel force time. In general, this parameter measures the time, in minutes, required for delamination to occur on a 1-inch (2.54 cm) wide sample, with a 150 g weight attached to one side of the sample. Therefore, the static peel force time of the crotch channel is higher than that of the anterior channel. Specifically, the static peel force time of the crotch channel can be higher than 50 minutes, or higher than 60 minutes, or higher than 70 minutes, while the static peel force time of the anterior channel is less than 50 minutes, specifically less than 40 minutes or less than 30 minutes. The crotch channel can have a static peel force time that is at least 20 minutes, at least 30 minutes, or at least 40 minutes higher than that of the anterior channel.

[0062] Crotch passages and anterior passages can generally be formed in roughly the same way, the difference being the bonding step used for the crotch passage, which is absent or much weaker for the anterior passage. In this document, when the term “passage” is used without further indication, it refers to any or all crotch passages and / or anterior passages, unless it is obvious from the context that it refers to a particular type of passage.

[0063] Advantageously, to prevent lateral leakage, all or at least some of the channels do not extend into any periphery of the absorbent material layer. In other words, at least one of each type of channel can advantageously be completely contained within the deposition area formed by the absorbent material. The channels in the core can specifically terminate at a distance of at least 5 mm from any outer edge of the absorbent layer. The crotch channel and the front channel can be separated from each other by a separation zone or buffer zone containing absorbent material. Figures 5 to 8 As shown, the minimum distance d between the front channel and the crotch channel can be, for example, at least 5 mm, specifically 5 mm to 20 mm. Maintaining a certain distance between the absorbent material and the front channel helps to prevent fluid collected in the crotch channel from being immediately conducted into the front channel, causing these front channels to disappear prematurely at the first flow of contaminated liquid.

[0064] On the other hand, when projected onto the longitudinal axis, the longitudinal positions of the front channel and the crotch channel can overlap, or be spaced apart by a distance l, which ranges from 0 mm to less than 20 mm, or 0 mm to less than 10 mm, or 0 mm to less than 5 mm. In this way, the front channel can begin at approximately the same longitudinal position where the crotch channel terminates, such that the absorbent core includes a channel from the front region of the article to at least the crotch region and preferably to the rear region without significant interruption. This continuity provides a beneficial effect on the channel's extension length of the absorbent core. The front channel and the crotch channel can also partially overlap in the longitudinal direction. These distances l and d can also be higher, especially if a relatively short crotch channel is used, such as... Figure 7 and Figure 8 As shown.

[0065] The front and crotch channels can be configured accordingly as one or more pairs of channels arranged symmetrically with respect to the longitudinal axis, such that the crotch channels are mirror images of each other with respect to the longitudinal axis, and similarly, the front channels are also mirror images of each other with respect to the longitudinal axis. This generally provides better fit and fluid distribution compared to cases where the channels are arranged randomly or asymmetrically. Any pair of channels can be joined together along the longitudinal axis, for example at their front and / or rear ends or at their center, to form, for example... Figure 8 The X-shaped channel, or another symmetrical shape such as U-shaped or V-shaped.

[0066] The crotch and front channels typically extend longitudinally, meaning that each channel extends at least as much in the longitudinal direction as it extends in the transverse direction. The crotch channel typically extends further in the longitudinal direction than the front channel, for example, at least twice as much in the longitudinal direction as the front channel (as measured previously after projection onto the longitudinal axis). At least some channels may have a width of at least 2 mm, or at least 3 mm, or at least 4 mm, up to, for example, 20 mm, or 16 mm or 12 mm along at least a portion of their length. The width of each channel may be constant over substantially the entire length of the channel or may vary along its length. For example, the channels may be straight and longitudinally oriented, with the width gradually decreasing or increasing from the front to the rear of the article. The width of the channels may be the same or different between different channels.

[0067] exist Figure 5 The exemplary core shown separately in the top view has a pair of crotch channels 26 and a pair of front channels 56. Of course, absorbent cores according to the invention may include more or fewer channels than those shown in the example. The absorbent core may also include a pair of channels, for example, in the rear region 64 of the article of manufacture.

[0068] Figure 5 The channels are curved. Some or all of the front channel and the crotch channel may be concave towards the longitudinal axis 80, as inverted brackets (especially at least the crotch channel 26). Either of the channels may have an arcuate portion, and the angle between the tangent of the arcuate portion and the longitudinal axis is greater than or equal to 20 degrees. Channels with such arcuate portions are disclosed, for example, in WO2014 / 093130A1 (Roe et al.). Of course, different shapes and orientations of the front channel and / or the crotch channel are possible. For example, at least one of the front channels and / or at least one of the crotch channels, or both channels, may be straight and parallel to the longitudinal axis, as in... Figure 7As exemplarily illustrated. The channel may also be partially or entirely straight and inclined relative to the longitudinal axis. The channel may have other shapes or orientations as described above. For example, the channel may be branched or U-shaped and / or form a pocket toward the rear of the article, especially for bonded crotch channels, as exemplarily disclosed in WO2014 / 093129A (Roe et al.). Channels that extend longitudinally in part and coincide with the longitudinal axis of the article may or may not be present; however, such channels may create a fold line in the middle of the article, which may cause the article to fold downward, potentially resulting in some loss of contact.

[0069] When existing in one or more symmetrical pairs relative to a longitudinal axis, the channels in each pair are spaced apart from each other on a portion of their longitudinal dimension or along their entire longitudinal dimension. At some points or along the entire length of the channels, the spacing may be, for example, at least 5 mm, or at least 10 mm, or at least 16 mm, as measured laterally. Some channels existing in a pair may also join at their bases to form a U-shape or V-shape, or may join towards their center to form a cross or X-shape, for example... Figure 8 shown.

[0070] Upper basal layer 16 and lower basal layer 16'

[0071] The absorbent core 28 includes an upper substrate layer 16 and a lower substrate layer 16' forming a core envelope sandwiching absorbent material in between. Various core envelope configurations are possible. The core envelope may specifically include two separate substrates 16, 16', as shown, which respectively form the top and bottom sides of the core envelope. Having two different substrates allows for easier deposition of the core adhesive on the inner surfaces of the top and bottom sides of the core envelope before combining these substrates to form the core envelope. The two substrates may be attached in a C-shaped wrap configuration or a sandwich configuration using two longitudinal seals 284', 286', and optionally a front seal 280' and a rear seal 282'. However, this core envelope configuration does not limit the invention, as any conventional core envelope configuration may also be used, such as a single substrate on which absorbent material is deposited and the remainder of the substrate is folded over the deposited absorbent material to form the other side of the core. This single substrate configuration can then be longitudinally sealed using a single longitudinal edge seal. The core package may also include two substrates arranged face-to-face (sandwich) with longitudinal side seals along their longitudinal sides.

[0072] The core-encapsulating material can be any material suitable for receiving and containing absorbent material. Typical substrate materials used to prepare conventional cores can be used, specifically paper, tissue paper, film, woven or nonwoven fabric, or any laminate of these materials. The core-encapsulating material can be specifically formed from a nonwoven fiber web, such as carded nonwoven fabric, spunbond nonwoven fabric (“S”), or meltblown nonwoven fabric (“M”), and laminates of any of these. For example, spun melt polypropylene nonwoven fabric is suitable, particularly nonwoven fabrics having a laminated web SMS or SMMS or SSMMS structure and a basis weight range of about 5 gsm to 15 gsm. Suitable materials are disclosed, for example, in US7,744,576, US2011 / 0268,932A1, US2011 / 0,319,848A1, and US2011 / 0,250,413A1. Nonwoven materials are typically made of synthetic fibers, such as PE fibers, PET fibers, and specifically PP fibers. The core encapsulation may also be at least partially formed from a component of the article that serves a function other than simply acting as a substrate for absorbing material. For example, a substrate may form the bottom side of the core encapsulation, and / or a distribution layer or top sheet may form the top side. However, the core encapsulation is typically made from one or more substrates whose sole or primary function is to receive and encapsulate the absorbent material, as previously described.

[0073] As used herein, the term "nonwoven layer" or "nonwoven fiber web" generally refers to an artificial sheet, fiber web, or layer formed by bonding or felting oriented or randomly oriented fibers together through friction and / or gluing and / or adhesion, or by wet abrasion, excluding paper and products of yarns or filaments bound together by weaving, braiding, tufting, or stitching, whether or not they have been additionally stitched. These fibers may be of natural or synthetic origin and may be short fibers, continuous filaments, or fibers formed in situ. Commercially available fibers have diameters ranging from less than about 0.001 mm to greater than about 0.2 mm and come in several different forms, such as short fibers (known as chemical short fibers or chopped fibers), continuous monofilaments (filaments or monofilaments), untwisted continuous filament bundles (tows), and twisted continuous filament bundles (yarns). Nonwoven fiber webs can be formed by a variety of methods, such as meltblown, spunbond, solution spinning, electrospinning, carding, and air-jet spinning. The basis weight of nonwoven fiber webs is usually expressed in grams per square meter (g / m²). 2 (or gsm) indicates.

[0074] like Figure 3As shown in Figure 4, the upper substrate layer 16 can substantially form the entire top side of the core wrapper, and the lower substrate layer 16' can substantially form the entire bottom side of the core wrapper, but this is not excluded from the possibility of the opposite. "Substantially forming the entire surface" means that (if present) outwardly extending flaps of another substrate that have been longitudinally folded can also form part of the surface under consideration. The first layer 16 may include two side flaps that extend laterally along the length of the core and are folded inward to each side edge 284, 286 of the absorbent core, and the flaps may be attached to the outer surface of the second substrate 16', for example, by using an adhesive seal along each C-shaped wrapper seal. Typically, one or two continuous or semi-continuous lines of adhesive may be applied along the length of the flaps to bond the inner surface of the flaps to the outer surface of the other substrate. Of course, an inverted configuration can also be used for the bottom substrate, thereby forming flaps on the top substrate.

[0075] The core may also include so-called sandwich seals, wherein a lower substrate layer and an upper substrate layer are bonded to each other face-to-face along one edge of the core, wherein the inner surface of each substrate is bonded to the inner surface of the other substrate. These sandwich seals can be formed, for example, using hot melt adhesive applied in the form of a series of strips along a direction perpendicular to the front and rear edges 280, 282 of the core. However, these end seals 280', 282' are optional, as many absorbent cores are open at the front and rear ends. Longitudinal edges can also be bonded using such sandwich seals.

[0076] The key structural features of the invention have been described in detail, and the following sections provide further details of some of the typical components present in absorbent articles. Of course, unless otherwise specified, the materials described below are optional and non-limiting.

[0077] Core adhesive

[0078] It is advantageous to have an inner core adhesive between the upper and lower substrate layers of the core. The inner core adhesive improves the adhesion of the absorbent material to the upper and / or lower substrate layers. The inner core adhesive can also form an adhesive portion 27, at least partially, between the substrate in the crotch channel and optionally the anterior channel. The inner core adhesive may also create a weaker adhesive portion 57 in the anterior channel (if these anterior channels have any adhesive portions). The two sides of the core wrapper can be locally pressed together in the region of the crotch channel while the adhesive is still hot and fluid to increase the strength of the adhesive bond in these regions.

[0079] The core adhesive can be applied to the inner surface of the upper and / or lower substrates on an area corresponding at least partially (e.g., at least 50% and up to 100%) to the deposition area of ​​the absorbent material, to at least partially fix the absorbent material. The core adhesive can be applied according to any known technique before the absorbent material is deposited on the nonwoven fabric, specifically as a series of longitudinally extending adhesive grooves, as known in the art, or alternatively by other non-contact application methods, such as spiral adhesive application. The core adhesive can thus be specifically present between the inner surfaces of the absorbent material and the bottom side of the core wrapper, and / or between the inner surfaces of the absorbent material and the top side of the core wrapper. An example of this method of partially covering the deposition area with core adhesive (also called auxiliary adhesive) to fix the absorbent material and thereby form a channel bond is disclosed, for example, in EP2,886,092 (Stelzig et al.). Fiber thermoplastic materials can also be present within the core wrapper to help fix the AGM particles, especially if the core does not contain cellulose fibers.

[0080] Top film 24

[0081] The topsheet typically forms the majority of the wearer's contact surface of the article and is the first layer that comes into contact with bodily fluids. The topsheet is preferably soft, gentle to the touch, and non-irritating to the wearer's skin. Furthermore, at least a portion of the topsheet is liquid-permeable, allowing liquids to easily penetrate its thickness. Any known topsheet can be used in this invention. Suitable topsheets can be made from a wide range of materials. Most topsheets are nonwoven materials or open-cell molded films, but other materials are also possible, such as porous foams, honeycomb foams, and woven materials. Typical diaper topsheets have a basis weight of about 10 gsm to about 28 gsm, specifically between about 12 gsm and about 18 gsm, but higher basis weights are possible if a wearer-contact surface with, for example, a very soft feel is desired.

[0082] The nonwoven topsheet can be made of natural fibers (e.g., wood or cotton fibers), synthetic fibers or filaments (e.g., polyester or polypropylene or bicomponent PE / PP fibers or mixtures thereof), or a combination of natural and synthetic fibers. If the topsheet includes nonwoven fibers, the fibers can be spunbonded, carded, wet-laid, melt-blown, hydroentangled, or otherwise processed as is known in the art. Specifically, the topsheet can be a spunbond PP nonwoven fabric. A suitable topsheet comprising a fiber web of short-fiber-length polypropylene fibers is manufactured by Veratec, Inc., a division of International Paper Company (Walpole, MA), under the name P-8.

[0083] The top plate may be of the type including multiple holes. At least some of the holes may have a diameter in the range of 1 mm.2 Up to 20mm 2 The area, and specifically, the top sheet can include an average of 1 to 20 holes / cm². 2 The porosity (the surface area of ​​all pores divided by the total surface area of ​​the top sheet, measured when the top sheet is relaxed, i.e., with just enough tension to smooth out any wrinkles) is advantageously in the range of 10% to 45%, specifically 25% to 40%, and more specifically 30% to 35%. Typically, the total area of ​​pores on the diaper surface can be between approximately 10 cm². 2 and about 50cm 2 Between, specifically between approximately 15cm 2 and 35cm 2 The area between. An example of an open top plate is disclosed in US 6,632,504 (Gillespie et al.).

[0084] Suitable colored nonwoven topsheets with a basis weight of 12 to 18 gsm and including multiple bonding points are also disclosed in WO 2011 / 163582 (Rinnert et al.). Each of the bonding points has a thickness of 2 mm. 2 Up to 5mm 2 The surface area of ​​the plurality of bonding points is 10 to 25% of the total surface area of ​​the top sheet.

[0085] Suitable shaped membrane topsheets are described in US 3,929,135, US 4,324,246, US 4,342,314, US 4,463,045, and US 5,006,394. Other suitable topsheets can be prepared according to US 4,609,518 and US 4,629,643. These shaped membranes can be obtained “DRI-WEAVE” from Procter & Gamble Company, Cincinnati, Ohio, and “CLIFF-T” from Tredegar Corporation, headquartered in Richmond, VA. Topsheets can also have a three-dimensional appearance and feel, or additional smaller three-dimensional layers may be present on top of the topsheet. Such additional three-dimensional layers can be used, for example, particularly to receive low-viscosity effluents such as the feces of young infants. Examples of such fluid-woven bilayer three-dimensional materials and processes for obtaining them have been disclosed, for example, in US2014 / 0,121,623A1, US2014 / 0,121,621A1, US2014 / 0,121,624A1, and US2014 / 0,121,625A1.

[0086] The top sheet may also be treated with a wetting agent to make it more hydrophilic. The wetting agent may be a surfactant as known in the art. Other possible treatments include, for example, special coatings with nanoparticles, as described, for example, in US 6,645,569, US 6,863,933, US 2003 / 148684 and US 2005 / 008839 (Cramer et al.) and US 7,112,621 (Rohrbaugh et al.). Any portion of the top sheet may also be coated with a detergent, as known in the art. Examples of suitable detergents include those described in US 5,607,760, US 5,609,587, US 5,643,588, US 5,968,025 and US 6,716,441. The top sheet may also include or be treated with an antimicrobial agent, some examples of which are disclosed in WO 95 / 24173. In addition, the top sheet, bottom sheet, or any portion thereof may be embossed and / or textured to provide a more fabric-like appearance.

[0087] Film 25

[0088] The backing sheet can be any backing sheet known in the art for absorbent articles. The backing sheet can be positioned directly adjacent to the absorbent core, facing the garment surface. The backing sheet prevents or at least inhibits soiling of articles such as sheets and underwear by absorbed and contained effluent. The backing sheet is typically impermeable to liquids (e.g., urine) or at least substantially impermeable. The backing sheet can be, for example, or comprise a plastic film, such as a thermoplastic film having a thickness of about 0.012 mm to about 0.051 mm. Those films typically have a basis weight as low as possible to save material costs, typically 10 gsm to 30 gsm, specifically less than 20 gsm. A low-basis-weight nonwoven fabric with coverage can be attached to the outer surface of the film to provide a softer feel.

[0089] Suitable film materials include breathable materials that allow vapors to escape from the absorbent article while still preventing or at least inhibiting effluent from permeating the film. Exemplary breathable materials may include materials such as: woven fiber webs; nonwoven fiber webs; composite materials such as membrane-coated nonwoven fiber webs; microporous membranes such as those manufactured by Mitsui Toatsu Co. (Japan) under the name ESPOIR NO and those manufactured by Tredegar Corporation (Richmond, VA) and sold under the name EXAIRE; and monolayer membranes such as those manufactured by Clopay Corporation (Cincinnati, OH) under the name HYTREL blend P18-3097.

[0090] The membrane may include at least about 10% by weight of filler particles, such as filler particles comprising calcium carbonate, such that the membrane has been stretched longitudinally to, for example, at least about 150%, with ruptures formed at the locations where the filler particles are positioned. The membrane may be biaxially stretched at least about 150% in both the longitudinal and transverse directions to cause ruptures at the locations where the filler particles are positioned. The breathable membrane typically has a “water vapor transfer rate” (WVTR) exceeding 300 g / m² / 24h. WVTR can be measured using the Desiccant Method as described in ASTM E96 / E96M – 14.

[0091] For example, US 6,075,179 discloses a suitable multilayer film comprising: a core layer made of an extrudable thermoplastic polymer, the core layer having a first outer surface and a second outer surface, a first skin layer attached to the first outer surface of the core layer to form a multilayer film, the multilayer film defining a total thickness. The first skin layer defines a first skin thickness and accounts for less than about 10 percent of the total thickness. The total thickness does not exceed about 30 micrometers, and the multilayer film is a liquid barrier and has a WVTR of at least 300 g / m² / 24 hours.

[0092] The film may further include a nonwoven fabric on its outermost surface to improve softness. Exemplary laminates including a breathable membrane and nonwoven layers are disclosed, for example, in WO2014 / 022,362A1, WO2014 / 022,652A1, and US5,837,352. The nonwoven web may specifically include a laminate of spunbond nonwoven web and / or a laminate of spunbond nonwoven web and meltblown nonwoven web. The laminate may also have a water vapor transport rate of at least 300 g / m² / 24 h. For example, US5,843,056 discloses a composite film that is substantially impermeable to liquids but permeable to vapors.

[0093] Anterior earpiece 46 and posterior earpiece 40

[0094] Absorbent articles typically include a front ear flap 46 and a back ear flap 40, as is known in the field of adhesive diapers. The ear flaps can be integral parts of the basic structure, for example, formed as side flaps from a top flap and / or a bottom flap. Alternatively, as... Figure 1 As shown, they can be separate elements attached by adhesive and / or heat embossing. The back ear flap 40 is preferably stretchable to facilitate attachment of the fastening strap 42 to the landing area 44 and to hold the adhesive diaper in place around the wearer's waist. The front ear flap 46 may optionally be elastic or stretchable to provide a more comfortable and conformal fit.

[0095] Barrier leg clamp 34 and bushing clamp 32

[0096] The absorbent article may also include a hoop member 30 that improves the fit of the article around the wearer's leg. Such hoops typically include a blocking leg hoop 34 and a bushing hoop 32. Hoop 30 may include a sheet of material, typically nonwoven, partially bonded to the article on one side and partially protruding away from the top sheet on the other side and thus standing upright from the plane defined by the top sheet, such as, for example… Figure 3 As shown. Both parts of the hoop can advantageously be elastic. The protruding portion of the hoop component is referred to herein as the blocking leg hoop 34, and can provide improved restraint of liquids and other bodily exudates near the joint of the wearer's torso and legs. The blocking leg hoop 34 extends at least partially on opposite sides of the longitudinal axis between the front and rear edges of the absorbent article, and is present at least adjacent to the center point C of the article.

[0097] The barrier leg cuff 34 may be defined by a proximal edge 37 and a free end edge 38 that are engaged to the rest of the article (typically the top piece), and is intended to contact the wearer's skin and form a seal. The barrier leg cuff 34 may be engaged with the base structure of the article at the proximal edge 37 by an adhesive portion, said adhesive portion being made by, for example, adhesive bonding, fusion bonding, or a combination of known bonding methods, such as those disclosed in WO2014 / 168,810A1 (Bianchi et al.). The adhesive portion at the proximal edge 37 may be continuous or discontinuous.

[0098] The barrier leg cuff 34 may be integrated with (i.e. formed by) the top or bottom sheet, or more typically formed from a separate material bonded to the rest of the article. Typically, the material of the barrier leg cuff may extend the entire length of the diaper, but is “adhesively bonded” to the top sheet towards the front and rear edges of the article, such that in these sections, the barrier leg cuff material remains flush with the top sheet. Each barrier leg cuff 34 may include one, two, or more elastic threads 35 near its free end edge 38 to provide a better seal.

[0099] In addition to the barrier leg cuffs 34, the article may also include a liner cuff 32, which is formed in the same plane as the base structure of the absorbent article, specifically at least partially enclosing between the top and bottom sheets, and typically positioned further laterally outward relative to the barrier leg cuffs 34. The liner cuffs 32 provide a better seal around the wearer's thighs. Typically, each liner cuff 32 will include one or more elastic bands or elastic elements 33, which are included in the base structure of the diaper, for example, between the top and bottom sheets in the leg opening area. Typically, the barrier leg cuffs 34 are positioned further inward than the liner cuffs 32. The barrier leg cuffs are therefore also referred to as the inner cuffs, and the liner cuffs as the outer cuffs.

[0100] For example, US 3,860,003 describes a disposable diaper providing a retractable leg opening having side wings and one or more elastic members to provide an elastic leg cuff (liner cuff). US 4,808,178 (Aziz) and US 4,909,803 (Aziz) describe disposable diapers with “upright” elastic flaps (barrier leg cuffs) that improve restraint on the leg area. US 4,695,278 (Lawson) and US 4,795,454 (Dragoo) describe disposable diapers with a double cuff, the double cuff comprising a liner cuff and a barrier leg cuff. All or part of the barrier leg cuff and / or liner cuff may be detergent-treated.

[0101] Collection layer 52

[0102] The absorbent article may advantageously include a collection layer 52 (sometimes referred to as a second top sheet) that functions to rapidly collect fluid away from the top sheet to provide good dryness for the wearer. The collection layer is typically placed directly below the top sheet. Optionally, a distribution layer (not shown) may be present, at least partially disposed below the collection layer 52. The collection layer may typically be or include a nonwoven material, such as SMS or SMMS material (including a spunbond layer, a meltblown layer, and another spunbond layer), but many other alternative materials are also known in the art and can be used interchangeably, specifically carded nonwoven fabrics. Nonwoven materials have the advantage of being manufactured outside of conversion processing lines and stored and used in rolls. Nonwoven materials may be latex-bonded. An exemplary upper collection layer is disclosed in US7,786,341. Carded resin-bonded nonwoven fabrics may be used, particularly when the fibers used are solid or round and hollow PET staple fibers (50 / 50 or 40 / 60 mixtures of 6-denier and 9-denier fibers). An exemplary binder is butadiene / styrene latex. Other available nonwovens are described in US6,645,569 (Cramer et al.), US6,863,933 (Cramer et al.), US7,112,621 (Rohrbaugh et al.), US2003 / 148684 (Cramer et al.), and US2005 / 008839 (Cramer et al.). The collecting layer can be stabilized by a latex binder such as styrene-butadiene latex binder (SB latex). Methods for obtaining such a lattice are known, for example, EP 149880 (Kwok) and US 2003 / 0105190 (Diehl et al.). The binder typically exists in the collecting layer in an amount ranging from about 12% to about 50%, for example, about 30%, based on the total weight of the collecting layer. SB latex can be traded under the name GENFLO. ™Obtained from 3160 (OMNOVA Solutions Inc.; Akron, Ohio).

[0103] Another typical collection layer can be a bonded carded fiber web, specifically a ventilated bonded carded fiber web (“TABCW”). A “bonded carded fiber web” refers to a fiber web made from short fibers fed through a combing or carding unit that breaks and aligns the short fibers longitudinally to form a generally longitudinally oriented fibrous nonwoven fiber web. This fiber web is then drawn through a heated drum, thereby creating a bonded portion throughout the fabric without applying specific pressure (ventilated bonding process). TABCW materials provide a low-density, loose, ventilated bonded carded fiber web. The fiber web may, for example, have a specific basis weight level of about 15 gsm to about 120 gsm (grams per square meter), specifically about 30 gsm to about 80 gsm. TABCW materials may, for example, comprise short fibers of about 3 to about 10 denier. Examples of such TABCWs are disclosed in WO2000 / 71067 (KIMDOO-HONG et al.). TABCW can be purchased directly from all common suppliers of nonwoven fiber webs used in absorbent products, such as Fitesa Ltd or Fiberweb Technical Nonwovens.

[0104] In addition to the first collection layer described above, another collection layer (not shown) may be used. For example, a tissue layer may be placed between the first collection layer and the distribution layer. Compared to the collection layer described above, the tissue may have enhanced capillary distribution characteristics. The tissue and the first collection layer may have the same size or may have different sizes; for example, the tissue layer may extend into the rear of the absorbent article compared to the first collection layer. An example of hydrophilic tissue is a 13 to 15 gsm high wet strength tissue made from cellulose fibers obtained from the supplier Havisx.

[0105] Distribution layer

[0106] The article may include another intermediate layer (not shown) located between the top sheet and the absorbent core, which will be referred to herein as a distribution layer. The function of the distribution layer is to distribute intruding fluid liquids onto a larger surface area within the article, allowing for more efficient use of the core's absorbency capacity. This distribution layer may have a smaller surface area than the area occupied by the absorbent core and typically does not extend beyond the edges of the core's occupied area. The distribution layer is typically made of a fibrous material, which may be based on synthetic fibers or cellulose fibers. The distribution layer may also include channels that at least partially or completely match the location and shape of all or any of the channels in the absorbent core. The same considerations regarding the shape, location, and orientation of the channels in the absorbent core are equally applicable to the channels in the distribution layer, and therefore will not be repeated herein.

[0107] The distribution layer can therefore be a fiber layer having a density of at least 50 g / m². 2 Specifically, 50g / m 2 Up to 300g / m 2 And advantageously at least 100g / m 2 The average basis weight is calculated as follows: the weight of the fiber divided by the distribution area in which the fiber is present (including the channel area in the distribution layer). The distribution layer may have a relatively low density. The density of this layer may vary depending on the compression of the article, but is typically in the range of 0.03 g / cm³ measured at 0.30 psi (2.07 kPa). 3 Up to 0.25 g / cm 3 Specifically, 0.05 g / cm 3 Up to 0.15 g / cm 3 For this purpose, the density of the intermediate layer is measured at the center point C of the article.

[0108] The fibrous material can be manufactured by air-forming the fibers on a rotary drum comprising several molds, each mold having the depth characteristics required for the desired fibrous material configuration. The resulting distribution layer can then be directly demolded onto another part of the article, such as a nonwoven carrier layer, and then integrated with the remainder of the article. Other layers, such as a collection layer 52, may be present between the distribution layer and either the top sheet or the absorbent core. When the nonwoven collection layer 52 is present in the article, the distribution layer may, for example, be deposited on the collection layer, and the two layers are further bonded to the absorbent core and the remainder of the article, as is known in the art.

[0109] The distribution layer is typically a fiber layer. The distribution layer can be a nonwoven material comprising fibers bonded together, giving the layer strong integrity and allowing it to be manipulated independently of the substrate. Alternatively, the distribution layer can be another type of fiber layer, specifically comprising or consisting of loose fibers with little or no interfiber bonding, deposited on a supporting substrate at varying basis weights to form an irregular distribution. A typical example of a distribution / intermediate material comprises or consists of cross-linked cellulose fibers. The distribution / intermediate layer may, for example, comprise at least 50% by weight of cross-linked cellulose fibers. Cross-linked cellulose fibers can be pleated, twisted, or crimped, or combinations thereof (including pleated, twisted, and crimped). This type of material has been used in the past as part of a collection system in disposable diapers, for example, US 2008 / 0312622 A1 (Hundorf). Cross-linked cellulose fibers provide high elasticity and therefore high resistance to compression under product packaging or use conditions (e.g., at the weight of an infant).

[0110] Exemplary chemically cross-linked cellulose fibers suitable for distribution layers are disclosed in US5,549,791, US5,137,537, WO95 / 34329, or US2007 / 118087. Distribution layers comprising cross-linked cellulose fibers may include other fibers, but the layer may include at least 50%, or 60%, or 70%, or 80%, or 90%, or even up to 100% cross-linked cellulose fibers (including cross-linking agents) by weight of the layer. Although the distribution material may comprise cellulose fibers, specifically cross-linked cellulose fibers, other materials are also possible.

[0111] Lower Acquisition and Distribution Layer (ADS)

[0112] The absorbent article may include a lower collection and distribution layer, referred to herein as the "lower ADS". The lower ADS serves as a temporary reservoir for liquids that have flowed through the absorbent material layer, since the liquid has not been absorbed by the absorbent material sufficiently quickly. The lower ADS is disposed between the absorbent material layer and a fluid-impermeable substrate. The lower ADS may be a single layer, thus also serving the function of the lower base layer 16', or the lower ADS may include several layers, such as a standard low-basicity lower base layer 16' and at least one additional bulking layer disposed between the lower base layer 16' and the substrate.

[0113] The lower ADS preferably comprises a relatively bulky material layer, thereby providing sufficient void volume to capture and retain fluid permeating through the absorbent material layer. The lower ADS may include, for example, a mask layer material disclosed in WO2019 / 241,009A1 (P&G, Tally, et al.). The bulky layer typically does not contain superabsorbent polymers. Simultaneously, the bulky layer preferably provides flexibility and does not have excessively high flexural stiffness. Such layers may in particular be jet-sprayed mesh, ventilated bonded nonwovens, or crimped spunbond nonwovens.

[0114] The bulky layer may contain continuous fibers, such as in spunbonded nonwoven fiber webs. The spunbonded nonwoven fiber web is preferably air-bonded or hydroentangled. In addition to hydroentanglement or air-bonding, the spunbonded nonwoven fiber web may undergo, or may not undergo, some localized bonding (e.g., spot bonding) using heat and / or pressure, thereby introducing locally bonded zones where the fibers melt together.

[0115] Preferably, the bulk layer comprises short fibers. Similar to nonwoven webs made of continuous fibers, short-fiber nonwoven webs are preferably air-bonded or hydroentangled. In addition to hydroentanglement or air-bonding, short-fiber nonwoven webs may undergo some local bonding (e.g., spot bonding) using heat and / or pressure, thereby introducing locally bonded zones where the fibers melt together.

[0116] Regardless of whether the bulky fiber web is made of continuous or short fibers, local bonding should not bond an excessively large surface area, thus adversely affecting the bulk and void volume of the nonwoven fiber web. Preferably, the total bonded area obtained by local bonding using heat and / or pressure (other than hydroentangling or ventilated bonding) should not exceed 20%, 15%, or 10% of the total surface area of ​​the bulky fiber web. Alternatively, the bulky nonwoven fiber web formed by the lower ADS should not undergo any bonding and consolidation except by hydroentangling or ventilated bonding. Thus, the advantageous properties of such nonwoven fiber webs can be used for their optimization.

[0117] Additional layers provided to absorbent articles typically increase the article's thickness and bulk volume. This can lead to increased flexural stiffness and, consequently, a close and tight fit between the article and the wearer's body, reducing wearer comfort. Furthermore, the increased bulk volume is generally undesirable, especially between the wearer's legs. However, according to the invention, the presence of longitudinally extending crotch and front channels provides improved flexibility to the absorbent article, thereby mitigating any of these drawbacks. Therefore, the article of the present invention is particularly suitable for articles with a lower ADS (Advanced Dysplasia of the Crotch), especially those with a relatively high basis weight.

[0118] Therefore, the absorbent article may optionally include a lower ADS disposed between the absorbent material layer and the substrate. Such a lower ADS typically has a density of about 10 g / m³. 2 The typical core substrate layer has a higher basis weight. The basis weight of the lower ADS, which can consist of a single layer or a combination of two or more layers, is typically around 20 g / m³. 2 Up to 120g / m 2 or 25g / m 2 Up to 110g / m 2 or 30g / m 2 Up to 100g / m 2 Within the range. The basis weight of the lower ADS is calculated by adding the basis weights of each layer disposed between the absorbent material layer and the film. Typically, this basis weight can be the basis weight of the bulky lower base layer 16' of a single lower ADS, or the basis weight of the lower base layer 16' and one (or more) additional bulky layers disposed between the lower base layer 16' and the film. The basis weights of the layers included in the lower ADS are usually uniform and indicated by the supplier, but if they are not uniform, the average basis weight can be simply calculated by dividing the weight of each layer by their area.

[0119] The lower ADS preferably comprises at least one layer having a fluffy structure. The use of crimped fibers facilitates the formation of this fluffy layer. Such fibers also exhibit the ability to provide a nonwoven layer with good elasticity, meaning that the nonwoven fiber web has a relatively good ability to recover its original thickness (or most of its original thickness) after being compressed for an extended period (e.g., when contained in a closed package containing highly compressed absorbent articles). The crimped fibers can have flat crimps (so-called two-dimensional crimps) or three-dimensional crimps, such as helical crimps. Bicomponent fibers are well known to be suitable for obtaining crimped fibers. Therefore, the lower ADS may comprise at least one layer having 30% by weight, or at least 40% by weight, or at least 50% by weight, or at least 70% by weight, or at least 90% by weight, or 100% by weight of crimped fibers based on the total weight of the layers as part of the lower ADS. The crimped fibers may be bicomponent fibers.

[0120] The thickness of the lower ADS is ideally within a range that balances good liquid absorption and retention properties (i.e., sufficient void volume within the nonwoven fiber web) with the need to avoid the lower ADS increasing the bulk volume of the absorbent article, thereby reducing wearer comfort. The thickness of the lower ADS can be from 0.1 mm to 2.0 mm, or from 0.2 mm to 1.0 mm, as measured according to the test methods described below. If the ADS comprises more than one layer, the thickness of each layer can be measured separately and added together to report the thickness of the lower ADS.

[0121] Furthermore, the lower ADS ideally includes at least one layer that exhibits good recovery after compression, given that the absorbent article is typically packaged under relatively high compression. Materials initially possessing properties suitable for use as a lower ADS (e.g., sufficient bulk and void volume) may lose many of these beneficial properties upon compression in packaging if their recovery capacity is insufficient. This capacity is reflected by the Z-compliance index and recovery percentage measurement methods described below. The lower ADS may consist of or include a layer having a compliance index greater than 4, preferably greater than 10, and a recovery percentage greater than 50%, preferably greater than 60%.

[0122] The nonwoven fabric that constitutes or forms the lower ADS may have undergone mechanical deformation. Such mechanical deformation can contribute to the bulk and openness of the nonwoven web, thus improving those properties required for use as the lower ADS. The lower ADS may include layers with a three-dimensional surface morphology (e.g., obtainable through mechanical deformation), known as "cavitation".

[0123] To avoid excessively increasing the stiffness of the absorbent article, one or more layers of the lower ADS may have a horizontal flexural drop greater than 60, preferably greater than 70, according to the test method described below. A higher horizontal flexural drop indicates that the material is more flexible relative to a lower value.

[0124] Other components

[0125] The absorbent article of the present invention may further include any other typical components known for the intended use of the article, not shown in the accompanying drawings, such as lateral barrier elements extending across the top sheet to form a reservoir for feces, detergent application on the top sheet, wetting indicator markings (including pH indicator markings) disposed between the absorbent core and the bottom sheet, etc. These components are well known in the art and therefore will not be discussed further herein. Refer to WO2014 / 093310, which discloses several examples of these components in more detail.

[0126] Absorbent articles may also include at least one elastic waistband (also referred to as an elastic waist structure) disposed parallel to and along the rear edge of the article, and less frequently parallel to and along the front edge of the article. Such a waistband helps provide an improved fit and restraint at the rear and / or front edges of the article. Elastic waist features are generally designed to stretch and contract elastically to dynamically conform to the wearer's waist. Elastic waistbands can be constructed in several different configurations. Non-limiting examples of rear and front waistbands can be found in WO2012 / 177,400 and WO2012 / 177,401 (Lawson), and US4,515,595, US4,710,189, US5,221,274, and US6,336,922 (VanGompel et al.).

[0127] Packaging

[0128] Multiple articles according to the invention can be packaged in a package for transport and sale. At least 50% of the articles in the package, and preferably all of the articles, can be articles according to the invention. The articles can be folded and packaged as is known in the art. The package can be, for example, a plastic bag or a cardboard box. Diapers can typically be double-folded along the transverse axis, and the ear flaps are folded inward before packaging. Absorbent articles can be stacked under compression to reduce the size of the package while still providing a sufficient number of absorbent articles for each package. By packaging absorbent articles under compression, caregivers can easily handle and store the packages, while also providing manufacturers with savings in distribution and inventory due to the size of the packages.

[0129] The absorbent articles can therefore be compressed and packaged with an “in-bag compression ratio” of at least 10%, specifically 10% to 50%, specifically 20% to 40%. As used herein, “in-bag compression ratio” is a quotient obtained by subtracting the stack height of 10 folded articles measured during compression within the bag (“in-bag stack height”) from the stack height of 10 folded articles of the same type before compression, and then multiplying by 100; that is, (1 - in-bag stack height / stack height before compression) * 100, expressed as a percentage. Of course, the stack in the bag does not need to have exactly 10 articles, but rather the measured value of the stack height of the articles in the package is divided by the number of articles in said stack, and then multiplied by 10. The method used to measure the “in-bag stack height” is described in more detail in the “Test Procedure”. Typically, a sample of articles before compression is obtained from the production line between the folding unit and the stacking filling unit. The stack height prior to compression is measured as follows: Ten articles are taken prior to compression and encapsulation, and their stack height is measured as per IBSH.

[0130] According to the “inner stacking height test” described herein, the absorbent article packaging of this disclosure may specifically have an “inner stacking height” of less than 110 mm, less than 105 mm, less than 100 mm, less than 95 mm, or less than 90 mm, specifically listing all 0.1 mm increments within and formed therein or thereby. For each value mentioned in the preceding sentence, it may be desirable to have an “inner stacking height” greater than 60 mm, or greater than 70 mm, or greater than 75 mm, or greater than 80 mm. Alternatively, according to the “inner stacking height test” described herein, the absorbent article packaging of this disclosure may have an “inner stacking height” of 60 mm to 110 mm, 75 mm to 110 mm, 80 mm to 110 mm, 80 mm to 105 mm, or 80 mm to 100 mm, specifically listing all 0.1 mm increments within and formed therein or thereby.

[0131] Preparation method

[0132] Top sheet 24, bottom sheet 25, absorbent core 28, collection layer 52, and other article components can be assembled in a variety of well-known configurations by adhesive bonding, thermal bonding, ultrasonic bonding, and / or pressure bonding, as is known in the art. Typically, adjacent layers are joined together using conventional bonding methods, such as adhesive coatings applied via troughing or spraying onto the entire surface or a portion of the surface of the layer, or thermal bonding, or pressure bonding, or combinations thereof. For clarity and readability, most of the bonding between the components is not shown in the figures. Unless specifically excluded, bonding between the layers of the article should be assumed to be present. Adhesives can generally be used to improve adhesion between different layers, such as between the bottom sheet and the core wrapping. The adhesive used can be any standard hot melt adhesive as known in the art. The individual components can be converted into absorbent articles according to any process known in the art. These bonded portions are generally not shown in the figures to maintain the readability of the figures, but they are present, as is known in the art.

[0133] If the article includes a collection layer or a dispensing layer with channels that do not contain material, the top sheet can be attached directly or indirectly to the absorbent core through these channels. The top sheet can thus be bonded to the top side of the absorbent core through the channels in the collection or dispensing layer, for example, by adhesive bonding (gluing). When a collection layer without channels is present between the top sheet and the dispensing layer with channels, the top sheet can also be indirectly bonded to the underlying layer.

[0134] According to one aspect of the present invention, a method for manufacturing an absorbent article may include the following steps:

[0135] i) Provide an upper basal layer and a lower basal layer;

[0136] ii) Optionally, apply the adhesive to the upper substrate and / or the lower substrate;

[0137] iii) Depositing absorbent material on at least one of the upper or lower substrate layers to form an absorbent layer, wherein the absorbent layer includes at least one crotch channel and a front channel, the channel being substantially free of absorbent material, and if an adhesive has been applied, the adhesive is present between the absorbent layer and the upper and / or lower substrate layers.

[0138] iv) Bond the upper and lower base layers together through the crotch channel adhesive portion through the crotch channel and optionally through the front channel adhesive portion through the weaker front channel adhesive portion to form an absorbent core.

[0139] v) Form one or more core-encapsulated seals (280', 282', 284', 286') to obtain an absorbent core;

[0140] vi) Assemble the resulting absorbent core with other absorbent components containing landing zone material such that the front channel at least partially overlaps with the landing zone.

[0141] The method may advantageously include the step of applying an inner core adhesive to the inner surface of the upper or lower substrate layer, such that at least a portion of the absorbent material region is secured to the top and / or bottom side of the core package with the adhesive.

[0142] The core adhesive may typically be located on at least one or both of the inner surfaces of the top and / or bottom sides of the core wrapper to provide better retention of the absorbent material. The core adhesive may also form or at least contribute to the adhesion of the crotch channel (and optionally the front channel, provided the front channel adhesion is weak). The core adhesive may be applied as a longitudinally extending stripe pattern, a spiral pattern, or any other pattern known in the art. The core adhesive may be applied to the core wrapper material before the absorbent material is deposited thereon, or alternatively to a second portion of the folded core wrapper, or added independently to the core wrapper material.

[0143] As described above, the upper and lower substrate layers can be any conventional material known in the art, typically nonwoven. Any known suitable technique can be used to deposit the absorbent material as a layer on the core-wrapping material. The deposition can be continuous, for example, as in an air-laid process, where a constant flow rate of particles and cellulose fibers is mixed in a chamber, which is then drawn toward the core-wrapping material by negative pressure on the other side of the air-laid chamber. The upper and lower substrate layers can typically be laid on a rotating drum during absorbent material deposition, wherein the air-laid chamber is static. The outer surface of the drum includes protrusions that match the shape of the desired channels, such that substantially no absorbent material is deposited in these areas. Alternative processes for depositing absorbent material while leaving substantially absorbent-free channel areas include those processes for absorbent cores without permeable felt, as generally described in AGM printing, which are generally disclosed in EP2,532,329, EP2,905,000A1, and EP2,905,001 (all by Jackles et al.).

[0144] The upper and lower base layers of the core are bonded to form one or more channel adhesive portions 27, as described above. This crotch channel adhesive portion may be provided, specifically, by an in-core adhesive and additional bonding methods, particularly where the additional bonding methods involve reinforcing adhesive and / or ultrasonic bonding and / or thermal bonding and / or additional pressure on the adhesive adhesive portion between the upper and lower base layers. The front channels may be completely unbonded, or if they include weaker adhesive portions, these adhesive portions may be specifically limited to, for example, adhesive portions provided by the same in-core adhesive as the crotch channel adhesive portion, but not including the additional bonding methods described above. For example, the crotch channel adhesive portion may be an adhesive adhesive portion in which the top and bottom sides of the core wrapper have been locally pressed together to increase the strength of the adhesive adhesive portion, while the core wrapper layers are not pressed together in the front channels and therefore do not form strong adhesive portions, even if they include some of the in-core adhesive. In another example, the crotch channel adhesive portion may be an adhesive adhesive portion complementary to an additional bonding method such as a thermal adhesive portion or an ultrasonic adhesive portion, and the front channel adhesive portion may not include an adhesive portion or may only include an adhesive adhesive portion of the same type as the crotch channel adhesive portion without the additional bonding method.

[0145] Test Procedure

[0146] Unless otherwise specified, the values ​​shown herein were measured according to the methods described below. Unless otherwise indicated, all measurements were performed at 21°C ± 2°C and 50% ± 5% RH, and samples should be kept under these conditions for at least 24 hours to reach equilibrium before testing. For example, the "static peel force time" was measured at 23°C, as described below.

[0147] Static peel force time

[0148] The purpose of the "Static Peel Force Time" (SPFT) test method is to measure the bond strength between the top and bottom sides of the core-encapsulated material within the channel. This test method measures how long the bond can withstand a constantly applied vertical force of approximately 150 grams under standardized conditions ("Static Peel Force Time").

[0149] equipment

[0150] Medium-sized chuck: Medium-sized binder clips, 25mm capacity (#72050). ACCO World Product. Other suppliers: Yihai Products (#Y10003), Universal OfficeProducts (#10210), Diamond (#977114), or equivalent. Chuck weight: 4.5g + / - 1g.

[0151] Large Binder Clips: 2 inches (50.8mm). ACCO WorldProduct. Other suppliers: Yihai Products, Universal Office Products, Diamond, or equivalent suppliers.

[0152] Test stand: RT-10 room temperature (shear tester) w / timer. ChemInstruments, 510 Commercial Drive, Fairfield, Ohio 45014-9797, USA; or equivalent. Must be placed in a vibration-free area.

[0153] Weights: 150g (+ / - 1g) TW150 shear tester weights with hooks on top (to attach to the clamps). ChemInstruments, 510 Commercial Drive, Fairfield Ohio 45014-9797, USA; or equivalent.

[0154] Cutting tools: scissors and a 25.4mm (1-inch) cutter (a readily available source, such as the JDC precision sample cutter manufactured by Thwings-Albert Instrument Company (Philadelphia USA, catalog number 99), with a cutting width of 25.4mm and an accuracy of at least + / - 0.1mm).

[0155] A metal ruler with millimeter graduations traceable to NIST, DIN, JIS, or other equivalent national standards, longer than the length to be measured.

[0156] Temperature: Testo-temperature device (or equivalent) for measuring the temperature at the sample height, with an accuracy of ±0.5℃ and ±2.5% RH within the range of -10℃ to +50℃. Testo GmbH & Co., Postbox 1140, D-79849 Lenzkirch (www.testo.com). Part number for Testo 625: 0563 6251.

[0157] Core fabrication:

[0158] Typically, the absorbent core is derived from commercial products (such as diapers) and can be extracted from the product as described below:

[0159] 1. Open the diaper with the top side facing up and place it flat on the table. Hold the diaper with one hand and carefully remove the ear flaps (40) and barrier bands (30) along the continuous adhesive portion (outer edge) on both sides of the garment.

[0160] 2. Gently remove the top film and acquisition system, taking care not to damage the core end seal (if present). The film does not need to be removed.

[0161] Preparation of channel samples ( Figure 9 ):

[0162] 1. Place each core under a desk lamp or UV lamp to identify the start and end points of each channel.

[0163] 2. Define the longitudinal center of the passage area using a ruler, and mark a line perpendicular to the longitudinal axis that passes through the center of the passage area.

[0164] 3. Place the core (28) on the support platform (900) equipped with the 25.4 mm wide cutter (901) and align it with the center line of the channel. Double-sided tape (902) can be used to hold the sample in place. The platform includes two grooves or gaps on each side of the area to be cut, allowing the cutter blade to penetrate the thickness of the core.

[0165] 4. Cut the core laterally to obtain a sample band whose center is located on the center line of the channel, and optionally check the width of the cut sample band (target = 25 ± 2 mm).

[0166] 5. Using the scissors, cut the 1-inch wide sample strip along the direction to obtain a sample (100) including the channel adhesive portion (27). A channelless flap (101) of at least 5 mm should be present between the channel adhesive portion and the inner edge (102) of the sample to ensure proper manipulation of the sample – see [link to sample details]. Figure 10 Obtain the left and right samples (if rented). Label the cut samples appropriately, such as left / right channels.

[0167] 6. During the test, the sample will be clamped on the outer edge (103). The outer edge (103) of the sample can be trimmed with the scissors; however, for the purpose of the test, the minimum channel distance (104) from the sample to the outer edge (103) should be sufficient to ensure that the core-wrapping material is properly clamped in the fixture. Typically, for this purpose, the minimum distance (104) between the channel and the outer edge should be at least 5 mm, and 20 mm is ideal.

[0168] 7. Gently remove any core absorbent material outside the channel located between the bottom and top sides of the core wrapper (see...). Figure 11For this purpose, if necessary, open any longitudinal side seals of the core wrapping on the other edge (103) (if the seals have been trimmed off).

[0169] Test Procedure (see) Figure 12 ):

[0170] The test instrument is set up in an area where the temperature is kept constant at 23°C, and the test instrument and the sample are ensured to have at least 2 hours to reach that temperature.

[0171] 1. Clamp the outer edge (103') of the bottom side (16') of the sample into the clamp of the large connector (120) chuck that is suspended at the top of the tester rod.

[0172] 2. Clamp another connector clamp (medium size) (121) at its outer edge (103) to the top side (16) of the core package. The inner edge (102) of the sample faces away from the experimenter.

[0173] 3. Slowly attach the 150g weight (122) to the medium-sized coupling clamp and slowly lower it until the weight hangs freely on the test sample.

[0174] 4. Once the weights are released, immediately press the timer reset button to start the timer at 0 minutes. Note: The timer must be checked to ensure it has started counting from 0.0 min. The operator should observe the numbers change from 0.0 min to 0.1 min.

[0175] 5. Repeat the above procedure for each prepared sample. The "test bench" allows for the testing of several samples in parallel.

[0176] 6. Once the sample weight falls onto the base plate due to breakage of the adhesive, the timer will stop. The base plate includes a switch connected to the timer so that the timer automatically stops when the weight falls. The recorded time is the "static peel force time" of the sample (in minutes). Note: If the weight falls due to the sample slipping out of the clamp (121) but the adhesive does not break, a new sample needs to be tested again.

[0177] 7. If the sample weight has not fallen after 999 minutes, the "Static Peel Force Time" will be reported as 999 minutes (maximum "Static Peel Force Time").

[0178] 8. For a commercially available article with a given construction, repeat the experiment on 10 different samples of 10 randomly selected diapers taken from 10 individual articles or cores, such as commercially sourced diaper packages, and average the results. The “static peel force time” is this average value.

[0179] Centrifugation retention capacity (CRC)

[0180] CRC is measured by the amount of liquid absorbed by superabsorbent polymer particles during free swelling in excess liquid. CRC is measured according to EDANA method WSP 241.2.R3 (12).

[0181] Thickness testing methods

[0182] The thickness of the lower ADS was determined using a thickness testing method. In this method, unidirectional pressure was applied to both sides of the substrate sample using two flat, parallel surfaces, and the resulting distance between the parallel surfaces was measured. All measurements were performed in a laboratory maintained at 23°C ± 2°C and 50% ± 2% relative humidity, with the test samples conditioned in this environment for at least 2 hours prior to testing. If the lower ADS comprises two or more layers, the procedure was repeated for each constituent layer, and intermediate results were added to report the combined thickness of the lower ADS.

[0183] Two parallel circular surfaces, each 5.6 cm in diameter, are horizontally oriented. If possible, measure them before integrating the sample material into the absorbent article. If this is not possible, take care not to contaminate or deform the sample layer when removing it from the product during removal from other layers (using a cryogenic spray, such as Cyto-Freeze, Control Company (Houston, Texas), if necessary). Take five equivalent rectangular samples from the material of the five products, such that the center of each sample corresponds to the center point C of the article. Each sample should be greater than 5.6 cm in length and width. The samples are then placed between the two parallel circular surfaces, ensuring that the sample completely covers each of the parallel surfaces and that the center of the material sample aligns with the center of the parallel circular surface.

[0184] The parallel surfaces were then joined together at a rate of 3.0 ± 1.0 mm / s until a pressure of 0.3 psi (2.1 kPa) was reached, and the spacing between the plates was measured and recorded within 2 seconds, accurate to 0.01 mm. The arithmetic mean of the plate spacing for 5 individual replicate samples was calculated and reported as the substrate thickness at 2.1 kPa, in millimeters (mm), accurate to 0.01 mm.

[0185] A suitable example of an apparatus for thickness methods is the Mitutoyo Digimatic Series 543 ID-C digital indicator (Mitutoyo America Corp., Aurora, Illinois, USA) or an equivalent, which has a round, flat "foot" at the end of the indicator gauge's moving axis. The indicator is mounted on a horizontal granite base such that the axis of the indicator gauge is vertically oriented and the plane of the round foot is parallel to the granite base. The size and weight of the round foot are set such that the gravity associated with the mass of the foot and the indicator axis, divided by the area of ​​the round foot, constitutes a gravity of 0.3 psi from the round foot on the granite base. A sample at least as large as the round foot is analyzed between the round foot and the granite base.

[0186] Z-compliance index and percentage recovery measurement methods

[0187] Principle: This method measures the ability of a fiber web, such as a nonwoven fabric, to be compressed in the z-direction under applied pressure and then recover to its original thickness after the applied pressure is removed.

[0188] Setup: A vertical orientation electronic caliper tester with an accuracy of at least 0.01 mm and 40 mm diameter circular feet can be used. The pressure applied to the sample by the feet can be adjusted by adding pre-selected weights. Measurements were performed at 0.85 ± 0.05 kPa and 15.4 ± 0.1 kPa.

[0189] Procedure: Measurements are performed at 23°C ± 2°C and 50%RH ± 2%RH. Unless otherwise specified, all samples should be kept in these conditions for at least 24 hours to reach equilibration before testing. If possible, measure the sample specimens before integrating them into the absorbent article. If this is not possible, care should be taken not to contaminate or deform the test sample layer when cutting the sample during material removal from other layers (if necessary, using a cryogenic spray, such as Cyto-Freeze, Control Company (Houston, Texas)). Cut the sample specimens into square specimens with a width of approximately 80 mm (or alternatively, if the material is not present in a suitable size within a material specimen with a width of approximately 50 mm).

[0190] Center the square sample under the caliper feet and measure and record the caliper thickness at 0.85 ± 0.05 kPa (P1), accurate to 0.01 mm (C1). Without removing the sample from the equipment, increase the pressure to 15.4 ± 0.1 kPa (P2) and measure and record the caliper thickness, accurate to 0.01 mm (C2). The pressure can be increased by adding appropriate weights to the caliper feet. Again, without moving the sample, reduce the applied pressure back to 0.85 ± 0.05 kPa (e.g., by removing additional weights) and measure and record the caliper thickness a third time (C3), accurate to 0.01 mm.

[0191] For the specimen being measured, the compliance index is defined as:

[0192] Flexibility index = (C1 - C2) / (P2 - P1)

[0193] And the measurements are recorded, accurate to 0.1mm. 3 / N.

[0194] The recovery rate is calculated as follows:

[0195] Recovery rate = C3 / C1 * 100%

[0196] Expressed and recorded as a percentage, accurate to 0.1%.

[0197] The above procedure was performed on five similar samples of the same nonwoven fabric. The arithmetic mean of the flexibility index values ​​of the five samples was calculated and reported as the flexibility index, accurate to 0.1 mm. 3 / N. Calculate the arithmetic mean of the recovery percentage values ​​of the five samples and report it as the recovery rate, accurate to 0.1%.

[0198] Bag stacking height test

[0199] The "inner stacking height" of absorbent product packaging is determined as follows:

[0200] Equipment: A thickness tester with a flat, rigid horizontal slide. The thickness tester is configured such that the horizontal slide moves freely in the vertical direction, always maintaining a horizontal orientation directly above a flat, rigid horizontal substrate. The thickness tester includes means for measuring the gap between the horizontal slide and the horizontal substrate, accurate to ±0.5 mm. The horizontal slide and the horizontal substrate are larger than the surface of the absorbent article package that contacts each slide, i.e., each slide extends beyond the contact surface of the absorbent article package in all directions. The horizontal slide applies a downward force of 850 g ± 1 g (8.34 N) to the absorbent article package, which is achieved by placing a suitable weight at the center of the top surface of the horizontal slide that is not in contact with the package, such that the total mass of the slide plus the added weight is 850 g ± 1 g. Such a testing apparatus is shown, for example, in Figure 19 of US2008 / 0312624A1.

[0201] Test Procedure: Before measurement, equip the absorbent product package at 21 ± 2°C and 50 ± 5% relative humidity. Raise the horizontal slide and center the absorbent product package under the horizontal slide with the absorbent product inside the package horizontally oriented. Fold any handles or other packaging features on the surface of the package against the surface of the package to minimize their influence on the measurement. Slowly lower the horizontal slide until it contacts the top surface of the package and then release it. Ten seconds after releasing the horizontal slide, measure the gap between the horizontal slides, accurate to ±0.5 mm. Measure five identical packages (packages of the same size and the same number of absorbent products) and report the arithmetic mean as the package width. Calculate and report “Inner Stack Height” = (Package Width / Number of Absorbent Products per Stack) × 10, accurate to ±0.5 mm.

[0202] Miscellaneous

[0203] Unless otherwise specified, this specification and claims refer to absorbent cores and articles that are dry and free of fluids before use and conditioned for at least 24 hours at 21°C + / - 2°C and 50 + / - 5% relative humidity (RH).

[0204] The dimensions and values ​​disclosed herein should not be construed as strictly limited to the precise numerical values ​​cited. Rather, unless otherwise specified, each such dimension is intended to represent the stated value and a range around which it is functionally equivalent. For example, a dimension disclosed as “40 mm” is intended to represent “approximately 40 mm”.

Claims

1. A personal hygiene absorbent article (20) having a front edge (10), a back edge (12), a longitudinal axis (80) extending hypothetically in a longitudinal direction from a middle of the front edge to a middle of the back edge, the personal hygiene absorbent article having a length (L) measured along the longitudinal axis, the personal hygiene absorbent article hypothetically comprising a front region (62) having a length of one third of the length of the personal hygiene absorbent article, a back region (64) having a length of one third of the length of the personal hygiene absorbent article, and a crotch region (63) located between the front region and the back region having a length of the remaining one third of the length of the personal hygiene absorbent article; the personal hygiene absorbent article comprising a liquid permeable topsheet (24), a liquid impermeable backsheet (25), a pair of fastening belts (42) disposed symmetrically on each side of the longitudinal axis in the back region, wherein the fastening belts are releasably fastenable to a landing zone (44) in the front region of the personal hygiene absorbent article to form a closed article having a waist opening and two leg openings; and an absorbent core (28) between the topsheet and the backsheet, wherein the absorbent core comprises a layer of absorbent material (60) between an upper substrate layer (16) and a lower substrate layer (16'); the layer of absorbent material comprising: i) at least one crotch channel (26, 26', 26'', 26''') substantially free of absorbent material and primarily disposed in the crotch region (63) of the personal hygiene absorbent article; wherein the upper substrate layer and the lower substrate layer are bonded to each other across the crotch channel by a crotch channel bond (27) having a crotch channel bond strength; ii) at least one front channel (56, 56') substantially free of absorbent material and primarily disposed in the front region (62) of the personal hygiene absorbent article, the front channel at least partially overlapping the landing zone (44); wherein the upper substrate layer and the lower substrate layer are not bonded to each other across the front channel (56'), or are bonded to each other across the front channel (56) by a front channel bond (57) having a front channel bond strength, wherein the front channel bond strength is weaker than the crotch channel bond strength.

2. The personal hygiene absorbent article (20) according to claim 1, wherein the crotch channel bond (27) comprises a first bonding method and an additional bonding method; and the front channel bond (57) comprises the first bonding method but not the additional bonding method.

3. The personal hygiene absorbent article according to claim 2, wherein the first bonding method is a hot melt adhesive and the additional bonding method comprises at least one selected from the group of bonding methods consisting of: applying pressure between the upper and lower base layers in the crotch channel to improve bonding of the layers by the adhesive when the adhesive is in an open state; supplemental adhesive; thermal bonding; mechanical bonding; ultrasonic bonding; or any combination thereof.

4. The personal hygiene absorbent article according to claim 3, wherein the hot melt adhesive of the first bonding method is a core inside glue present between the absorbent material layer (60) and the upper base layer (16) and / or between the absorbent material layer (60) and the lower base layer (16').

5. The personal hygiene absorbent article according to any of claims 1-4, wherein the front channels and the crotch channels do not extend to any of the edges of the absorbent material layer.

6. The personal hygiene absorbent article according to any of claims 1-4, wherein the length (L26) of at least one crotch channel is at least twice as long as the length (L56) of at least one front channel when measured projected on a longitudinal axis.

7. The personal hygiene absorbent article according to any of claims 1-4, wherein at least one crotch channel has a length that is at least 50% of the length (L') of the absorbent core when measured projected on a longitudinal axis.

8. The personal hygiene absorbent article according to any of claims 1-4, wherein the front channels and the crotch channels are separated by absorbent material such that the closest distance (d) between the channels is at least 5 mm.

9. The personal hygiene absorbent article according to any of claims 1-4, wherein the front channels and the crotch channels overlap or are separated by a distance (1) on a projection on an imaginary line parallel to the longitudinal axis, the distance being less than 10 mm.

10. The personal hygiene absorbent article according to any of claims 1-4, wherein the personal hygiene absorbent article further comprises an acquisition layer (52) located between the topsheet (24) and the absorbent core (28).

11. The personal hygiene absorbent article according to any of claims 1-4, wherein the personal hygiene absorbent article comprises a lower acquisition and distribution system between the absorbent material layer (60) and the backsheet (25), wherein the lower acquisition and distribution system consists only of the lower substrate layer of the core, or wherein the lower acquisition and distribution system consists of the lower substrate layer and one or more additional layers, and wherein the basis weight of the lower acquisition and distribution system is in the range of 20 g / m2 2 to 120 g / m 2 .

12. The personal hygiene absorbent article according to any of claims 1-4, wherein the crotch channel bonds (27) have a static peel time that is at least 20 minutes greater than the static peel time of the front channel bonds (57).

13. The personal hygiene absorbent article of any of claims 1-4, comprising: a pair of crotch channels, the pair of crotch channels being arranged symmetrically with respect to the longitudinal axis, wherein the crotch channels are connectable or disconnectable to each other; and a pair of front channels, the pair of front channels being arranged symmetrically with respect to the longitudinal axis, wherein the front channels are connectable or disconnectable to each other.

14. The personal hygiene absorbent article of any of claims 1-4, comprising: a first crotch passage and a second crotch passage, the first crotch passage and the second crotch passage being disposed symmetrically with respect to the longitudinal axis and defining a central absorbent zone, the central absorbent zone comprising absorbent material disposed between the first crotch passage and the second crotch passage; and a first lateral absorbent zone and a second lateral absorbent zone, the first lateral absorbent zone and the second lateral absorbent zone comprising absorbent material and being disposed laterally outwardly of the first crotch passage and the second crotch passage, respectively, wherein for at least a first transverse segment of the core having a first length of at least 10 mm in the longitudinal direction, the basis weight of the absorbent material in the central absorbent zone is higher than the basis weight of the absorbent material in each of the lateral absorbent zones; and for at least a second transverse segment of the core having a second length of at least 10 mm in the longitudinal direction, the basis weight of the absorbent material in the central absorbent zone is lower than the basis weight of the absorbent material in each of the lateral absorbent zones.

15. The personal hygiene absorbent article according to any of the claims 1-4, wherein the front passage and the crotch passage are separated by absorbent material such that the closest distance (d) between the passages is from 5 mm to 20 mm.

16. The personal hygiene absorbent article according to any of the claims 1-4, wherein the front passage and the crotch passage overlap or are separated by a distance (1) on an imaginary line parallel to the longitudinal axis, the distance being between 0 mm and 8 mm.

17. The personal hygiene absorbent article according to any of the claims 1-4, wherein the personal hygiene absorbent article further comprises an acquisition layer (52) located between the topsheet (24) and the absorbent core (28), wherein the acquisition layer is a nonwoven acquisition layer.

18. The personal hygiene absorbent article according to any of claims 1-4, wherein the personal hygiene absorbent article comprises a lower acquisition and distribution system between the absorbent material layer (60) and the backsheet (25), wherein the lower acquisition and distribution system consists only of the lower substrate layer of the core, or wherein the lower acquisition and distribution system consists of the lower substrate layer and one or more additional layers, and wherein the basis weight of the lower acquisition and distribution system is in the range of 20 g / m2 2 to 120 g / m 2 , wherein the lower acquisition and distribution system comprises at least one lofty layer having a Z-flexibility index of more than 4 and a recovery percentage of more than 50%, as measured by the Z-flexibility index and recovery percentage measurement method.

19. A method for manufacturing a personal hygiene absorbent article according to any of the preceding claims 1 to 18, the method comprising the steps of: i) providing an upper substrate layer and a lower substrate layer; ii) optionally applying a hot melt adhesive to the upper substrate layer and / or the lower substrate layer; iii) depositing absorbent material on at least one of the upper substrate layer or the lower substrate layer to form an absorbent material layer, wherein the absorbent material layer comprises at least one crotch passage and a front passage, the passages being substantially free of absorbent material, and if adhesive has been applied, the adhesive is present between the absorbent material layer and the upper substrate layer and / or the lower substrate layer; iv) bonding the upper substrate layer and the lower substrate layer to each other by crotch passage bonds through the crotch passage and optionally by weaker front passage bonds through the front passage, v) forming one or more core wrap seals (280', 282', 284', 286') to form an absorbent core; vi) assembling the absorbent core thus obtained with the other absorbent article components comprising the topsheet, the backsheet, the pair of fastening tapes and the landing zone, so that the front channel at least partially overlaps the landing zone, to obtain the personal hygiene absorbent article according to any of the preceding claims 1 to 18.

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