Absorbent article with channels

Abstract

The absorbent article (1) comprises an absorbent core (21) surrounded by a liquid permeable core cover (5) having a longitudinal centerline (Lc) and comprising an upper core cover layer (24) and a lower core cover layer (25). The absorbent core (21) has a pair of longitudinally extending side edges (26, 27) and a pair of laterally extending end edges (28, 29). The core cover layers (24, 25) are connected in side seals (33, 34) that extend along the side edges (26, 27) of the absorbent core (21). The absorbent core (21) comprises one or more longitudinally extending channels (35, 36) disposed at a predetermined distance from the side seals (33, 34), each of the one or more channels (35, 36) being free or substantially free of absorbent material and having a channel seal (37, 38) extending therethrough. The channel seals (37, 38) join the upper and lower core cover layers (24, 25) of the core cover (5) within the channels (35, 36), and the sealing strength of the channel seals (37, 38) is higher than the sealing strength of the first and second side seals (33, 34) of the absorbent core (21), respectively.

Description

Technical Field

[0001] The present disclosure relates to an absorbent article having an absorbent core surrounded by a liquid-permeable core cover including an upper core cover layer and a lower core cover layer. The upper core cover layer and the lower core cover layer are connected within a first side seal extending along a first side edge of the absorbent core and within a second side seal extending along a second side edge of the absorbent core. The absorbent core includes one or more channels extending longitudinally at a predetermined distance from each of the first side seal and the second side seal, and each of the one or more channels has a channel seal that extends therein and joins the upper and lower layers of the core cover within the channel.

Background Art

[0002] Disposable absorbent articles, such as infant diapers, absorbent pants, incontinence protectors, and other items for absorbing bodily fluids like sanitary napkins, face a conflict between the requirements of sufficient absorption capacity and leak safety and the wearer's comfort and freedom of movement. Therefore, there is a demand for highly absorbent articles that are not bulky, are flexible, and fit the wearer's body well. It is highly desirable for wearers to feel no restriction or discomfort when wearing absorbent articles, while being confident that the article is efficient in preventing leaks. For adult users, it is particularly important that the pants-type garment resembles regular underwear as closely as possible and can be worn discreetly under regular, form-fitting clothing. To provide sufficient absorption capacity while offering thin absorbent articles, a large proportion of the absorbent material may be superabsorbent material, or simply known as "superabsorbent." Superabsorbent may be combined with absorbent fibers, mainly cellulose pulp fibers, to create a fibrous network that helps distribute liquid within the absorbent core and maintain particulate superabsorbent material within the core. Superabsorbent materials are polymeric materials incorporated into absorbent articles, usually in the form of fibers, particles, or granules. Superabsorbent materials can absorb several times their own weight in liquid during the expansion and formation of a hydrogel. It has been found that absorbent materials containing large amounts of superabsorbent material lose their initial flexibility and wearer comfort when they absorb liquid and expand. High-impact areas of absorbent articles, such as the crotch area of ​​a diaper, containing large amounts of absorbent material distributed over a relatively small area, can become thicker and harder when the article absorbs liquid. Furthermore, a concern for disposable absorbent articles is to utilize the available absorption capacity of the absorbent material as completely as possible in order to minimize material consumption during the manufacturing of the absorbent article. Therefore, it is desirable to be able to utilize the full absorption capacity of the superabsorbent material. In absorbent cores with high superabsorbent material content, such as 50% or more superabsorbent material, and relatively low amounts of cellulose pulp fibers, or those without cellulose fibers, it has been proposed to provide additional stabilization of the absorbent core.

[0003] Patent Document 1 proposes stabilizing an absorbent core and counteracting sagging in the crotch area of ​​an absorbent article by forming two longitudinally extending channel sealings within the absorbent core. The absorbent core is enclosed within a core cover, and the channel sealings are arranged to connect the upper side of the core cover to the lower side of the core cover, dividing the absorbent core into a central segment and two lateral segments. As the absorbent material within the absorbent core absorbs bodily fluids and expands, the core cover acts as an expansion restricting means by limiting the expansion space for the absorbent material in the different segments. As a result, the expanding absorbent material exerts outward pressure on the core cover, leading to an increase in the rigidity of the absorbent core in the crotch area of ​​the absorbent article. Particularly high rigidity may therefore be achieved within the central segment of the absorbent core between the two channel sealings. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] International Patent Application Publication No. WO2019 / 125231A1 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] This disclosure is based on the insight that an absorbent article having improved fit, body conformity and wearer comfort, and superior absorbency and leak safety, is at least partially achieved by the properties of claim 1. Modified forms of the disclosure are described in the dependent claims and the following description. [Means for solving the problem]

[0006] The absorbent articles referred to herein may include, for example, wearable disposable absorbent articles in the form of open diapers, pull-up diapers, belted diapers, incontinence clothing, and feminine hygiene clothing, as well as disposable absorbent inserts, such as incontinence shields or sanitary napkins worn inside supportive clothing, such as support pants or regular underwear. The articles are used to absorb, distribute, and accumulate various types of bodily exudates while providing the wearer with a high level of comfort and dryness during wear.

[0007] This disclosure relates to an absorbent article having an absorbent core, the absorbent core comprising an absorbent material. The absorbent core is surrounded by a liquid-permeable core cover, the core cover comprising an upper core cover layer and a lower core cover layer. The article and the absorbent core have a longitudinal direction and a transverse direction perpendicular to the longitudinal direction, with the longitudinal centerline extending in the longitudinal direction. The absorbent core has a first side edge and a second side edge, the first and second side edges of the absorbent core having a main extension in the longitudinal direction, a first end edge and a second end edge, the first end edge and the second end edge having a main extension in the transverse direction. The upper core cover layer and the lower core cover layer are connected within a first side seal extending along the first side edge of the absorbent core and within the second side edge of the absorbent core. The absorbent core comprises one or more channels extending longitudinally at predetermined distances from the first side seal and the second side seal, respectively. Each of the one or more channels is free of or substantially free of absorbent material and has a channel seal extending therein, the channel seal bonding the upper and lower layers of the core cover within the channel, and the sealing strength of the channel seal is higher than the sealing strength of the first and second side seals of the absorbent core, respectively.

[0008] One or more channel seals prevent separation of the upper and lower core cover layers, thereby limiting the thickness-direction expansion of the absorbent core near the channels. The channel seals are preferably permanent seals, or at least the main portion of each channel seal is a permanent seal that does not rupture during normal use and handling of the absorbent article. Permanent seals withstand the forces generated by the expansion of the absorbent material within the absorbent core and remain undamaged throughout the entire use of the absorbent article. Side seals are breakable seals that rupture under the influence of forces applied to the side seals as the absorbent material within the absorbent core absorbs and expands fluid. Breakable side seals, along with channel seals, primarily facilitate the expansion of the absorbent material in the lateral or transverse directions of the absorbent core and absorbent article.

[0009] As measured by the test methods disclosed herein, the sealing strength of one or more channel seals may be 2.5N / 25mm or more, such as 3N / 25mm or more, and the sealing strength of the first and second side seals may be 2.0N / 25mm or less, such as 1.5N / 25mm or less.

[0010] The sole requirement for a channel seal is that it does not rupture under the pressure that may be applied to the seal during normal use; therefore, there is no upper limit to the sealing strength of one or more permanent channel seals. In the case of ruptureable first and second side seals, the sealing strength may be sufficient to be high enough to maintain the integrity of at least a portion of the side seal while the absorbent material between the channel seal and the side seal remains dry. In some examples, the upper and lower core cover layers may be held together simply by frictional forces within the portion of the core cover that extends laterally beyond the absorbent core.

[0011] The side seals may be partially breakable seals and partially permanent seals. A portion of the side seal located adjacent to the side edge of the core may be breakable, while the outer portion of the side seal located at a predetermined distance from the side edge may be a permanent seal that prevents the core cover layers from completely separating from each other.

[0012] The side seals and channel seals may be adhesive seals, welded seals, or any combination of adhesive and welded seals. The seals may be formed as a continuous bond line, or by separate bond elements arranged along the seal.

[0013] The side seal may be a seal with extremely low integrity, such as a mechanical seal formed by, for example, sewing the upper and lower core layers together with a needle or embossing them.

[0014] The first side seal, the second side seal, and each channel seal may be adhesive seals. The sealing strength of the seal may be controlled by varying the basis weight of the adhesive applied within the seal. Thus, the basis weight of the adhesive in each channel seal may be higher than the basis weight of the adhesive in the first side seal and the second side seal, respectively. The basis weight of the adhesive may also vary along the seal. In a channel seal, the basis weight of the applied adhesive may be higher at the longitudinal center of the channel seal than at one or both ends of the channel seal, allowing it to rupture upon expansion of the absorbent material while the center of the channel seal remains undamaged. The permanently sealed portion of one or more channel seals may extend to a portion of the absorbent core located on an inelastic crotch material, such as an inelastic crotch panel or inelastic crotch area of ​​the outer cover of an absorbent article, such as absorbent pants or an absorbent open diaper. The ruptureable end portions of one or more channel seals may extend to portions of the absorbent core located on the elastic front and rear body panels of the absorbent article.

[0015] In absorbent articles such as those disclosed herein, the basis weight of the adhesive in each channel seal is 3 g / m².2 From 15g / m 2 Within the range of 3g / m 2 The above is also acceptable. The basis weight of the adhesive in each side seal is 0.5 g / m². 2 From 5g / m 2 Within the range of 5g / m 2 The following is also acceptable.

[0016] In thermal seals and welded seals, such as ultrasonically welded seals, the sealing strength may be controlled by changing parameters such as sealing temperature, energy supply, sealing time, and sealing pressure, and / or by changing the sealing pattern.

[0017] The core cover may be formed from a single continuous cover material that surrounds the absorbent core, with the first and second side edges of the absorbent core positioned inside the corresponding first and second side folds within the continuous cover material, and the first and second side seals positioned laterally inward within the corresponding first and second side folds.

[0018] Alternatively, the upper core cover layer and the lower core cover layer may be separate core cover layers with an absorbent core sandwiched between them.

[0019] In absorbent articles as disclosed herein, the absorbent article may comprise a liquid-permeable top sheet and a liquid barrier layer, with the absorbent core positioned between the liquid-permeable top sheet and the liquid barrier layer. The liquid-permeable top sheet and the liquid barrier layer are provided in addition to an upper core cover layer and a lower core cover layer, the upper core cover layer facing the liquid-permeable top sheet and the lower core cover layer facing the liquid barrier layer.

[0020] An absorbent core comprising a liquid-permeable top sheet, a liquid barrier layer, and a core cover may be manufactured as a separate unit and may be part of, or constitute, an absorbent assembly or "core pack" that is subsequently attached to the front and rear panels of an open-type or pant-type wearable article, and to the outer cover of an open-type or pant-type wearable article.

[0021] As disclosed in this specification, the absorbent core of an absorbent article may comprise from 5% to 80% of a superabsorbent material, preferably from 30% to 80% of a superabsorbent material, in at least a part of the absorbent core disposed within the crotch portion of the absorbent article. Thus, the superabsorbent content may be lower at the front end portion and / or the rear end portion of the absorbent core than at the central portion of the absorbent core.

[0022] The superabsorbent material is a polymeric material and may be in the form of particles, granules, fibers, flakes, or the like.

[0023] The absorbent core may comprise a mixture of cellulose pulp fibers and a superabsorbent material.

[0024] A large amount of superabsorbent material within the absorbent core provides a high absorption capacity and the ability to chemically bond the absorbed fluid, leading to a highly leak-safe and dry inner surface absorbent article even after absorbing a large amount of fluid, while enabling the production of a thin and discrete absorbent article. The thin superabsorbent-containing article further has pre-use advantages as it occupies less space during packaging, transportation, storage, and on store shelves.

[0025] One or more channels may be configured by two channels that extend spaced apart from each other and are symmetrically disposed on each side of the longitudinal centerline between the longitudinal centerline and one of the corresponding first and second side seals.

[0026] The length of each of the one or more channels in the longitudinal direction of the article may be in the range of 50 millimeters to 500 millimeters, such as 75 millimeters to 400 millimeters, 100 millimeters to 300 millimeters, or 150 millimeters to 200 millimeters.

[0027] The absorbent core may have any suitable shape within a plane defined by the longitudinal and transverse directions, such as an hourglass shape or a T shape.

[0028] The absorbent core may comprise two or more parts having different absorption capacities. The absorbent core may also be a contoured core with a three-dimensional shape, where the central part of the absorbent core is located between a first end portion and a second end portion of the absorbent core, as seen in the longitudinal direction, and the central part of the absorbent core has a thickness greater than the thickness of the first end portion and a thickness greater than the thickness of the second end portion.

[0029] The central part of the absorbent core may have a uniform first thickness, the first end portion may have a uniform second thickness, and the second end portion may have a uniform third thickness. The first thickness may be equal to the second thickness. The central part of the absorbent core may be separated from the first and second end portions, respectively, by corresponding first and second transition sections.

[0030] The first end portion may be the front end portion, and the first transition section may be a front transition section having a longitudinal extension of 5 mm to 30 mm, such as 10 mm to 20 mm; the second end portion is the rear end portion, and the second transition section is a rear transition section having a longitudinal extension of 20 mm to 80 mm, such as 30 mm to 60 mm. The thickness of the absorbent core preferably changes linearly within the transition section between the end portion and the center.

[0031] The ratio between the thickness of the central part of the absorbent core and the thickness of the first end portion may be in the range of 4 to 1.5, and the ratio between the thickness of the central part of the absorbent core and the thickness of the second end portion may be in the range of 4 to 1.5.

[0032] The end portions may have equal thickness. However, end portions with different thicknesses are also conceivable in absorbent articles such as those disclosed herein. The front end portion may have greater thickness than the rear end portion.

[0033] The length of the absorbent core in an absorbent article as disclosed herein is determined as the distance between a point on the first edge of the absorbent core where the first edge intersects the longitudinal centerline and a point on the second edge of the absorbent core where the second edge intersects the longitudinal centerline, and the length of the absorbent core is in the range of 300 to 700 millimeters, such as 350 to 600 millimeters or 400 to 500 millimeters.

[0034] In an absorbent core having a thickened center, the thickened center may have a length of approximately 30% to 70% of the length of the absorbent core, such as 40% to 60% or 45% to 55% of the length of the absorbent core. The length of the thickened center may also be approximately half the length of the absorbent core.

[0035] The absorbent core within an absorbent article as disclosed herein may have any planar shape, such as rectangular, T-shaped, or hourglass. The hourglass shape includes all configurations of a core where the ends are wider than the center. Planar shapes with a narrower center than the ends may be preferred over a rectangular shape because the narrower center fits more comfortably between the wearer's legs. Furthermore, a narrow center of the absorbent core may allow for greater lateral expansion of the core during use of the absorbent article without causing discomfort.

[0036] Absorbent articles as disclosed herein may have a three-dimensional core with a thicker center and thinner edges, the core being surrounded by a core cover having an upper layer and a lower layer. The upper and lower layers may be formed from a single web material or from two web materials. The cover material may be a nonwoven material. The core has one or more sealed channels disposed within it, such as two sealed channels symmetrically arranged on each side of a centerline extending in the longitudinal direction of the article. The upper and lower layers of the core cover are joined to each other by channel seals disposed within one or more channels. The upper and lower layers are also joined to each other by side seals extending along the side edges of the absorbent core. One or more channels are without absorbent material, implicitly indicating that the upper and lower layers of the core cover are directly joined to each other within the channel seals. The channel seals are permanent seals as defined herein, and the side seals are breakable seals as defined herein. The side seal ruptures under the influence of the expansion force applied to the side seal by the absorbent material within the core as the absorbent material absorbs fluid and expands, thereby allowing the absorbent core to expand laterally over the absorbent article. Thus, the ruptured side seal provides additional expansion space along the side edges of the absorbent core, counteracting undesirable thickness and stiffness in the side portions of the absorbent core. The absorbent core may also be molded in a plane, such as having an hourglass shape with a center of the absorbent core narrower than the first and second end portions.

[0037] In a three-dimensional absorbent core as disclosed herein, the thinner end portions may have a uniform or substantially uniform thickness, and the thicker central portion may have a uniform or substantially uniform thickness. The transition section may be located between the thicker central portion and the thinner central portion, and the thickness of the absorbent core preferably decreases linearly or substantially linearly from the central portion to the end portion within the transition section. The end portions may be a designated front end portion and a designated rear end portion, with the rear end portion having a greater extension in the longitudinal direction of the absorbent article than the front end portion. The rear transition section may have a greater extension in the longitudinal direction of the absorbent article than the front transition section, as disclosed herein.

[0038] As disclosed herein, the core cover may be formed by another upper cover layer and another lower cover layer forming the lower portion of the core cover, and both the upper and lower core cover layers surround the absorbent component and are sealed together at least along the side edges of the absorbent core. Preferably, the upper and lower core cover layers are sealed together along the entire circumferential surface of the absorbent core.

[0039] If the core cover is formed from a single layer of material, the single layer of material may surround the absorbent core or may be formed as a tubular structure into which the absorbent components are inserted. This means that the core cover is sealed at least longitudinally, and the ends of the core cover may be left open. Preferably, the core cover is sealed so that the absorbent core is completely enclosed inside the core cover. Furthermore, the core cover may be made of three or more layers of material.

[0040] The basis weight of core cover materials used in this specification is 5 g / m². 2 From 20g / m 2The range may also be as follows. The core cover material may be made of thermoplastic polymer materials such as polyolefins, polyesters, polyamides, and combinations thereof. The core cover material may be nonwoven materials, perforated plastic films, meshes, etc. The nonwoven layer may be formed by any of the various different processes known in the prior art, such as spunbond, air laminating, meltblown, or bond card web forming processes. The nonwoven layer may be made of a thin layer of co-formed nonwoven materials such as SMS (spunbond / meltblown / spunbond) nonwoven material, SMMS (spunbond / meltblown / meltblown / spunbond) nonwoven material, or SS (spunbond / spunbond) nonwoven material. The thermoplastic polymer material in the nonwoven layer may be polypropylene, or composite fibers of polypropylene and polyethylene, or combinations thereof.

[0041] The absorbent core may consist of a single absorbent component layer. Absorbent cores comprising two or more layers are also conceivable in absorbent articles as disclosed herein.

[0042] An absorbent article as disclosed herein comprises an absorbent core surrounded by a liquid-permeable core cover comprising an upper core cover layer and a lower core cover layer. The absorbent core has a pair of longitudinally extending side edges and a pair of transversely extending end edges. The core cover layers are connected by side seals extending along the side edges of the absorbent core. The absorbent core comprises one or more longitudinally extending channels, such as two channels or three channels, located at a predetermined distance from the side seals, each of which has a channel seal extending therein, which is absent or substantially absent of absorbent material. The one or more channel seals bond the upper and lower core cover layers of the core cover within the channel, and the sealing strength of the channel seals is higher than the sealing strength of the first and second side seals of the absorbent core, respectively.

[0043] Absorbent articles as disclosed herein may be modified within the scope of the appended claims. For example, the materials and dimensions used for the different layers forming an absorbent article as disclosed herein may be modified as shown above. The absorbent article may further include any useful components or mechanisms known in the art, as known in the art, and depending on the type of absorbent article intended, such as fluid capture and distribution components, leg elastics, upright gathers, crotch and waist elastics, side panels, fastening systems, wetness indicators, skincare agents, and disposal means. [Brief explanation of the drawing]

[0044] [Figure 1] This is a plan view of an extended absorbent pant-type article, as seen from the inner surface of the pant-type article, with an absorbent assembly and an opening side seam. [Figure 2] This is an enlarged view of the absorbent assembly within the pants-type article shown in Figure 1, which has an absorbent core enclosed within a core cover. [Figure 3a] This is a cross-sectional view of the absorbent assembly shown in Figure 2, along line III-III, when the absorbent core is in a dry state. [Figure 3b] This is a cross-sectional view of the absorbent assembly in Figure 2, along line III-III, when the absorbent core is wet. [Figure 4] This figure shows the pant-type item in Figure 1, with the side seams closed and not stretched, as seen before use. [Figure 5] This diagram shows how the test specimen is mounted inside the clamp of the test equipment. [Figure 6] This diagram shows how the test specimen is mounted inside the clamp of the test equipment. [Modes for carrying out the invention]

[0045] Different aspects of this disclosure are described in full below with reference to the accompanying drawings. The embodiments disclosed herein can be realized in many different ways and should not be construed as being limited to the embodiments described herein. The absorbent articles shown in the drawings are panty-type articles, but it should be understood that absorbent cores, such as those described in the examples, may be used in any disposable absorbent article for absorbing urine, feces, and / or vaginal secretions, as disclosed herein.

[0046] The figures are schematic diagrams, and individual components such as material layers are not necessarily depicted to isometric scale. The pant-type article shown in the drawings is a simplified article, and the article may include other mechanisms such as barrier cuffs. Also, it should be understood that the waist elastic material disclosed herein is optional, and any other suitable type of waist elastic material may be used. The side seams may be re-closable side seams, and the pant-type article may be equipped with fastener elements to provide re-closability of the side seams.

[0047] Referring first to Figure 1, a pant-type incontinence product 1 in the form of a pant-type incontinence product for adult users is shown. The pant-type product 1 is shown in Figure 1 in an unfolded, flat state with all elastic elements fully extended. The pant-type product has a longitudinal direction L and a transverse direction T perpendicular to the longitudinal direction, and the longitudinal centerline Lc extends in the longitudinal direction L.

[0048] The pants-type item 1 is viewed from the inner surface, which is the surface facing the wearer's body when the item is being worn, and is opposite to the outer surface of the pants-type item 1 that faces the clothing.

[0049] The pants-type article 1 comprises an absorbent assembly 20 located within the front portion 3, the rear portion 4, and the crotch portion 6 of the pants-type article 1, extending longitudinally L forward over the front portion 3 and backward over the rear portion 4. The absorbent assembly 20 extends longitudinally L from the front portion 3 into the rear portion 4 through the crotch portion 6. The absorbent assembly 20 in the pants-type article shown in the drawing is a separately manufactured component comprising an absorbent core 21 enclosed between the upper core cover layer 24 and the lower core cover layer 25 of the core cover 5, and further enclosed between the liquid permeable top sheet 22 and the liquid barrier layer 23. The absorbent core 21 is located between the top sheet 22 and the liquid barrier layer 23, with the upper core cover layer 24 facing the liquid permeable top sheet 22 and the lower core cover layer 25 facing the liquid barrier layer 23.

[0050] As disclosed herein, the provision of the absorbent core 21 is not limited to absorbent articles having an absorbent core that is applied to an article as a component of a pre-fabricated absorbent assembly that already has a top sheet and a liquid barrier layer.

[0051] The front portion 3 has a front waist edge 7 extending in the lateral direction T, and a pair of front edges 8 and 9 extending in the longitudinal direction L. The rear portion 4 has a rear waist edge 10 extending in the lateral direction T, and a pair of rear edges 11 and 12 extending in the longitudinal direction L.

[0052] The first front edge 8 is joined to the first rear edge 11 within the first side seam 14, and the second front edge 9 is joined to the second rear edge 12 within the second side seam 15 to create a pair of pants-type article 1 having a waist opening 16, a first leg opening 17, and a second leg opening 18, as shown in Figure 4.

[0053] The side seams 14 and 15 of the pant-type article 1 may be substantially band-shaped joints formed by ultrasonic welding or heat welding. The side seams generally have a width of about 5 to 10 millimeters in order for the pant-type article 1 to withstand the forces it is subjected to during wear and to have sufficient strength to allow for adequate manufacturing tolerances. It is also known that the side seams may have a width of less than 5 mm.

[0054] It is generally desirable that soiled panty-type garments can be easily removed without having to pull them down over the user's legs. Therefore, the side seams are generally made to be detachable by manual force, allowing the user or caregiver to separate the side seams before removing the soiled panty-type garment.

[0055] The waist opening 16 is defined by the front panel waist edge 7 and the rear panel waist edge 10. The first leg edge 19' defines the first leg opening 17, and the second leg edge 19'' defines the second leg opening 18.

[0056] Referring to Figure 2, the absorbent core 21 has an hourglass shape with a first side edge 26, a second side edge 27, a first end edge 28, and a second end edge 29. The first side edge 26 and the second side edge 27 of the absorbent core 21 have a main extension in the longitudinal direction L, and the first end edge 28 and the second end edge 29 have a main extension in the lateral direction T.

[0057] The first channel 35 and the second channel 36 are located within the absorbent core 21 and extend longitudinally L at predetermined distances from the first and second side edges 26 and 27 of the absorbent core 21, respectively, on both sides of the longitudinal centerline Lc. The channels 35 and 36 contain little to no absorbent material.

[0058] The upper core cover layer 24 and the lower core cover layer 25 are connected to each other by a first side seal 33 extending along the first side edge 26 of the absorbent core 21 and by a second side seal 34 extending along the second side edge 27 of the absorbent core 21. In addition, the upper and lower core cover layers 24 and 25 are connected by a first channel seal 37 extending into the first channel 35 and by a second channel seal 38 extending into the second channel 36.

[0059] As disclosed herein, the sealing strength of the first and second channel seals 37, 38 is higher than that of the first and second side seals 33, 34 of the absorbent core 21. The sealing strength of the first and second channel seals 37, 38 may be 2.5 N / 25 mm or higher, while the sealing strength of the first and second side seals 33, 34 may be 2.0 N / 25 mm or lower.

[0060] At least the main portion of the channel seals 37, 38 is a permanent seal that does not rupture during normal use and handling of the absorbent article. Therefore, the channel seals 37, 38 remain undamaged or substantially undamaged even after the absorbent article has absorbed a liquid. The side seals 33, 34 are breakable seals with low sealing strength such that they rupture under the influence of the force applied to the side seals 33, 34 as the absorbent material in the absorbent core 21 absorbs fluid and expands. The permanent or substantially permanent channel seals 37, 38 restrict the expansion of the absorbent article 1 in the thickness direction, while the breakable side seams 33, 34 allow the absorbent material to expand laterally or transversely. Therefore, within the region of the absorbent core 21 where the channels 35, 36 are located, the combination of the permanent or substantially permanent channel seals 37, 38 and the breakable seals 33, 34 causes the absorbent core 21 to expand mainly in the transverse direction T.

[0061] As disclosed herein, the breakable side seals 33, 34 and channel seals 37, 38 may be adhesive seals. However, welded seals or combinations of adhesive and welded seals are also possible for the core cover seals 33, 34, 37, 38.

[0062] The upper and lower cover core layers 24, 25 may be formed from a single continuous cover material that surrounds the absorbent core 21. In the pant-type absorbent article shown in the drawing, the upper and lower core cover layers 24, 25 are formed from a separate web of material with the absorbent core 21 sandwiched between the core cover layers 24, 25.

[0063] Depending on the type and size of the absorbent article in which one or more channels are arranged, as disclosed herein, the length of the channels may range from 50 millimeters to 500 millimeters.

[0064] In absorbent pants for adult users with incontinence, such as absorbent article 1 shown in the figure, channels 35 and 36 are preferably located in the crotch portion 6 of the article, which is the narrow part of the article that is placed between the user's legs when the article is worn. The narrow crotch portion 6 of the absorbent article is the part of the article that receives the majority of excreted bodily fluids, such as urine. The crotch portion 6 must therefore have excellent absorbency with respect to fluid capture, fluid distribution, and absorption capacity. The channels 35 and 36 within the absorbent core 21 contribute to rapid fluid capture and facilitate fluid distribution by directing the fluid flow toward the front and rear portions 3 and 4 of the absorbent article 1. In absorbent article 1 shown in the figure, the length of channels 35 and 36 substantially corresponds to the length of the crotch portion 6 and may typically be in the range of 100 to 250 millimeters.

[0065] In wearable incontinence products such as open-type and pull-up diapers, the channel typically has a length of about 30% to 50% of the total length of the absorbent core. In smaller absorbent products such as incontinence shields and sanitary napkins, the channel may extend almost to the end of the absorbent core, such as up to 80% of the total length of the absorbent core.

[0066] To improve the absorption capacity within the narrow crotch portion 6 of the absorbent article 1, the central portion 51 of the absorbent core 21, positioned between the first end portion 52 and the second end portion 53 of the absorbent core 21, as seen in the longitudinal direction L, has a greater thickness than the end portions 52 and 53. In the absorbent article 1 shown in the drawing, the first end portion 52 is the front end portion 52 of the absorbent core 21, and the second end portion 53 is the rear end portion 53 of the absorbent core 21.

[0067] The central part 51 of the absorbent core 21 has a uniform thickness, and the first end portion 52 and the second end portion 53 of the absorbent core 21 each have a uniform thickness, and the central part 51 of the absorbent core 21 is separated from the first end portion 52 and the second end portion 53, respectively, by corresponding first transition sections 54 and second transition sections 55. The thickness of the absorbent core 21 decreases linearly from the central part 51 of the absorbent core 21 to the end portions 52 and 53 of the absorbent core 21 within the transition sections 54 and 55. The rear end portion 53 has a larger extension in the longitudinal direction of the absorbent article 1 than the front end portion 52. In the absorbent core 21 shown in Figure 2, the rear transition section 55 has a larger extension in the longitudinal direction L of the absorbent article 1 than the front transition section 54.

[0068] However, the transition section may have an extension equal to the longitudinal direction of the absorbent article, or the front transition section may be longer than the rear transition section. An absorbent core having a thickened center and thinner end portions, but without transition sections between different parts of the core, is also conceivable for an absorbent article as disclosed herein. Furthermore, the center and end portions may have non-uniform thickness.

[0069] The ratio between the thickness of the central part 51 of the absorbent core 21 and the thickness of the front end portion 52 may be in the range of 4 to 1.5, and the ratio between the thickness of the central part 51 of the absorbent core 21 and the thickness of the second end portion 53 may be in the range of 4 to 1.5. The thinner end portions 52 and 53 may have the same thickness or different thicknesses.

[0070] Furthermore, it should be understood that the three-dimensional shape of the absorbent core is optional for absorbent articles as disclosed herein, and the absorbent core may be planar or substantially planar. In a planar or substantially planar absorbent core, the absorption capacity within the absorbent core may differ in different parts of the core as a result of different amounts of superabsorbent material distributed in different parts of the core.

[0071] The absorbent core 21 disclosed herein may comprise any material suitable for absorbing discharged waste, such as cellulose fluff pulp, tissue layers, superabsorbent polymers (superabsorbent materials), hydrogel foam materials, absorbent nonwoven materials, and other absorbent foam materials. The absorbent core may comprise nonabsorbent components such as rigid elements, molding elements, and binders. Various types of liquid receptacles and liquid distribution elements may also be included in the core.

[0072] The absorbent core 21 preferably comprises superabsorbent material in an amount of 5% to 80% by weight of superabsorbent material, such as 30% to 80% by weight of superabsorbent material, at least in the central part 51 of the absorbent core 21. As described herein, the superabsorbent content may be lower in the central part 51 of the absorbent core 21 and lower in the front end portion 52 and / or rear end portion 53 of the absorbent core, or it may be the same in all parts of the absorbent core 21.

[0073] Superabsorbent materials are polymer materials and may be in the form of particles, granules, fibers, flakes, etc.

[0074] As disclosed herein, the absorbent core 21 may comprise a mixture of absorbent cellulose fibers, such as cellulose pulp fibers and superabsorbent materials.

[0075] The large amount of superabsorbent material within the absorbent core allows for the manufacture of thin, separate absorbent articles while providing high absorption capacity and the ability to chemically bond and fix the absorbed fluid, resulting in absorbent articles with high leak safety and a dry inner surface even after absorbing a large amount of fluid.

[0076] The superabsorbent material absorbs liquid during the expansion and formation of the aqueous gel. To fully utilize the absorption capacity of the superabsorbent material, the absorbent article must provide sufficient expansion space for the superabsorbent material. Since the absorbent core is enclosed within the core cover 5, the expanding superabsorbent material exerts pressure on the core cover. In the central part 51 of the absorbent core 21, where channels 35, 36 with permanent channel seals 37, 38 are located, the expansion space is constrained within the region between channels 35, 36, causing this region to grow somewhat thicker and more rigid until the core cover prohibits further expansion.

[0077] The absorbent core 21 has an hourglass shape, and the distance between the side edges 26 and 27 of the absorbent core 21 is greater at the edge portions 28 and 29 of the absorbent core 21 than in the intermediate region 60 of the absorbent core 21, where the absorbent core has a narrower width than the edge portions 28 and 29.

[0078] Figures 3a and 3b show cross-sections along line III-III through the absorbent core 21 in Figure 2. Figure 3a shows the absorbent core 21 in a dry state before it absorbs any liquid, and Figure 3b shows the absorbent core 21 in a wet state after absorption and expansion.

[0079] In the figure, the absorbent core 21 is surrounded between the upper core cover layer 24 and the lower core cover layer 25, and between the liquid permeable top sheet 22 and the liquid barrier layer 23. The absorbent core 21 is positioned between the top sheet 22 and the liquid barrier layer 23, with the upper core cover layer 24 facing the liquid top sheet 22 and the lower core cover layer 25 facing the liquid barrier layer 23.

[0080] The top sheet 22 and the liquid barrier layer 23 extend beyond the circumferential surface of the absorbent core 21 and are bonded to each other within an edge seal 41 that extends outward along the circumferential surface of the absorbent core 21, along the side edges 26, 27 and end edges 28, 29 of the absorbent core 21. The edge seal 41 between the top sheet 22 and the liquid barrier layer 23 is preferably a permanent seal.

[0081] When the absorbent core 21 absorbs bodily fluids, the absorbent material within the absorbent core 21 expands, and as shown in Figure 3b, the portion of the absorbent core 21 positioned between channels 35, 36 and trapped between permanent channel seals 37, 38 takes on a sausage-like shape with absorbent material that completely fills the available space between channels 35, 36, the top sheet 22 and upper core cover layer 24 bulge upward, and the liquid barrier layer 23 and lower core cover layer 25 bulge downward. The absorbent material positioned in the portion of the absorbent core 21 positioned between channels 35, 36 by the permanent channel seals 37, 38 applies pressure to the ruptureable side seals 33, 34, causing the side seals 33, 34 to rupture and provide lateral expansion space for the absorbent material. In this way, the absorbent core may absorb liquid and expand while the side edges 26, 27 of the absorbent core 21 remain soft and comfortable. As can be inferred from Figures 3a and 3b, the lateral expansion of the absorbent core 21 causes the side edges 26 and 27 of the absorbent core to move outward in the lateral direction T, thereby gradually destroying the hourglass shape of the absorbent core.

[0082] As described herein, as shown in Figure 3b, the channel seals 37, 38 may be breakable seals at the ends of channels 35, 36, and it is desirable to control the direction of expansion such that the absorbent core 21 has a somewhat larger width in the middle of channels 35, 36, and the portion of the absorbent core 21 positioned along the side edges 26, 27 expands mainly laterally.

[0083] The liquid-permeable top sheet 22 may comprise or be made of a nonwoven material. Other suitable top sheet materials include hemp fiber, porous foam, perforated plastic film and laminate, and combinations of such materials. The most suitable material for the top sheet is one that is soft, non-irritating to the skin, readily permeates bodily fluids, and exhibits low re-wetting.

[0084] The liquid barrier layer 23 may consist of a thin plastic film, such as a polyethylene or polypropylene film, a nonwoven material coated with a liquid-impermeable material, a hydrophobic nonwoven material resistant to liquid penetration, or a laminate of a plastic film and a nonwoven fabric. The liquid barrier layer material may be breathable to allow vapors to escape from the absorbent body while further preventing liquids from passing through the liquid barrier layer material.

[0085] The top sheet and the liquid barrier layer may be connected to each other, for example, by adhesive bonding, gluing, or thermal or ultrasonic welding. The top sheet and / or liquid barrier layer may further be attached to the core cover by any method known in the industry, such as adhesive bonding, thermal bonding, or welding.

[0086] A pant-type article as disclosed herein may have a two-part chassis having a crotch panel connected to the front panel along the crotch edge of the front panel and connected to the rear panel along the crotch edge of the rear panel. The front and rear panels may be made of elastic or elasticized web material or elastic laminate material, and the crotch panel may be made of inelastic web material or inelastic laminate material. Alternatively, the pant-type article may have a one-piece chassis having an inelastic outer or inner cover web extending over the entire distance between the waist edge of the front panel and the waist edge of the rear panel, the cover web constituting the inelastic layers of the front and rear panels respectively and constituting the crotch web material in the crotch area of ​​the pant-type.

[0087] The elastically stretchable front body panel and the elastically stretchable rear body panel may comprise, or be made of, a stretchable and bonded laminated elastic web material.

[0088] A suitable stretch-bonded laminate may comprise a nonwoven material layer or web, such as spunbond, air-laid, wet-laid, carded, electron-spinned, or melt-blown nonwoven fabric. The nonwoven materials may be bonded by any suitable technique, such as needle stitching, hydro-entanglement, ultrasonic welding, or thermal bonding.

[0089] The fibers of nonwoven materials used herein may be artificial fibers, natural fibers, or mixtures of artificial and natural fibers. Examples of artificial fibers include single-component, composite-component, and multi-component fibers of polymers such as polyolefins, polyesters, and polyacrylates, and regenerated fibers such as viscose fibers and modal fibers. Examples of natural fibers include cellulose fibers such as pulp fibers, cotton fibers, flax, and hemp fibers.

[0090] A pant-type article 1 as disclosed herein may have an elastic waist mechanism 90 positioned along a waist opening 16. The elastic waist mechanism 90 may be formed by one or more elastic elements extending parallel to the front panel waist edge 7 and the rear panel waist edge 10. One or more elastic waist elements may be incorporated into the front portion 3 and the rear portion 4, or may be applied as a separate waistband attached to the front panel waist edge 7 and the rear panel waist edge 10. The pant-type article 1 shown in the drawings has an elastic waist mechanism 90 extending around the entire circumference of the waist opening 16. However, the elastic waist mechanism may be positioned along only a portion of the waist opening, such as along only the rear waist edge, along only the front waist edge, or along only a portion of one or both of the front and rear waist edges, the portion having a length shorter than the entire length of the corresponding waist edge.

[0091] The elastic material in the elastic elements positioned along the leg openings 17, 18 and waist opening 16 as disclosed herein may be any suitable elastic material, such as natural or synthetic rubber, thermoplastic polyurethane or styrene block copolymer or thermoplastic elastomer such as elastane, also known as spandex (polyurethane polyurea copolymer). The elastic elements may be elastane type, commercially available under the trade name "LYCRA", but any suitable elastic yarn may be used.

[0092] Nonwoven web materials used in absorbent articles as disclosed herein may comprise thermoplastic materials. The nonwoven web materials are typically incorporated into joints and seams within the absorbent article, and it is desirable that the nonwoven webs be weldable by thermal or ultrasonic welding processes. Examples of polymers suitable for use in fibrous nonwoven webs as disclosed herein include polyethylene polypropylene and other polyolefin homopolymers and copolymers and polyesters. Weldable nonwoven webs have a high content of thermoplastic components, preferably containing at least 50% thermoplastic fibers, more preferably at least 80% thermoplastic fibers.

[0093] Testing Method Test method for measuring sealing strength At least 10 days must elapse between the time of manufacturing the item and the time of measuring its sealing strength.

[0094] The core, with its surrounding cover layer, is carefully separated from the other components of the absorbent article. If the lower core cover layer cannot be separated from the backing sheet of the absorbent article without damaging the lower core cover layer, the backing sheet must remain attached to the lower core cover layer when performing sealing strength tests.

[0095] The exposed core with the core cover layer is placed flat on the support surface. If elastic material is present within the core, the core should be stretched and secured in place on the support surface using tape strips, mechanical fasteners, or similar.

[0096] Rectangular specimens, 25 mm wide, are drawn from the core, with each specimen containing the portion of the seal to be tested. The specimens are drawn in the width direction of each specimen parallel to the longitudinal centerline of the core, and in the length direction of each specimen perpendicular to the longitudinal centerline of the core. The specimens are drawn so that the seal extends across the outer edge of the specimen, and the inner edge portions of the upper and lower core cover layers form cover flaps extending toward the longitudinal centerline of the article. Any loose absorbent material between the core cover flaps is removed. The core cover flaps may be extended and / or reinforced with high-friction tape to ensure stable and slip-free mounting within the tension tester clamp. It is important that the longitudinal edges of the test specimen are flat and free from fracture notches.

[0097] The samples are drawn in close proximity to each other. For example, eight 25mm wide test samples may be drawn from a seal that is 210mm long, with 10mm of the seal remaining at one end and not used for testing.

[0098] As described above, the prepared samples are conditioned for 24 hours in an environment controlled at a temperature of 23°C ± 1°C and a relative humidity of 50% ± 5%. The tests are performed in this same environment.

[0099] The samples are tested with a conventional tension tester, such as those commercially available from Lloyd Instruments or the Instron Corporation.

[0100] The core cover flap is inserted vertically into the clamp of the tension tester. The clamp should be the same width as or wider than the sample. During insertion, tension on the seal, as well as any excess slack in the sample being tested, should be avoided. The upper crosshead of the instrument is then set to move at a constant speed of 300 mm / min until the upper core cover layer separates from the lower core cover layer along the seal being tested. The maximum force measured is registered in Newtons / 25 mm (N / 25 mm). Figures 5 and 6 show how the test piece is mounted within the clamp of the test instrument.

[0101] The sealing strength of the seal being tested is an arithmetic mean based on all individual samples that can be cut along the seal. For example, the strength of the 210 mm long seal described above is the average sealing strength obtained from testing eight test pieces cut along the seal. [Explanation of Symbols]

[0102] 1. Pants-type item 3 Front part 4 Rear part 5 Core Cover 6 Crotch area 7 Front waist edge 8 Front edge 9 Front edge 10 Rear waist edge 11 Posterior edge 12 Posterior edge 14 Side seams 15 Side seams 16 Waist opening 17 Leg opening 18 Leg opening 20 Absorbent Assembly 21 Absorbent core 22 Top sheet 23 Liquid barrier layer 24 Upper core cover layer 25 Lower core cover layer 26 Side edge 27 Side edge 28 Edge 29 Edge 33 Side seal 34 Side seal 35 channels 36 channels 37 Channel Seal 38 Channel Seal 41 Edge seal 51 Center 52 End part 53 End part 54 Transition Section 55 Transition Section 60 intermediate area 90 Elastic waist mechanism

Claims

1. An absorbent article (1) comprising an absorbent core (21), wherein the absorbent core (21) comprises an absorbent material, the absorbent core (21) is surrounded by a liquid-permeable core cover (5), the core cover (5) comprises an upper core cover layer (24) and a lower core cover layer (25), the absorbent article (1) and the absorbent core (21) have a longitudinal direction (L) and a transverse direction (T) perpendicular to the longitudinal direction, the center line (Lc) in the longitudinal direction extends in the longitudinal direction (L), and the absorbent The absorbent core (21) has a first side edge (26) and a second side edge (27), and the first side edge (26) and the second side edge (27) of the absorbent core (21) have a main extension that extends in the longitudinal direction (L) and a first end edge (28) and a second end edge (29), and the first end edge (28) and the second end edge (29) have a lower main extension that extends in the transverse direction (T), and the upper core cover layer (24) and the lower core cover layer (25) are the first side edge of the absorbent core (21) A first side seal (33) extending along (26) is connected to a second side seal (34) extending along the second side edge (27) of the absorbent core (21), the absorbent core (21) comprises a plurality of channels (35, 36) extending in the longitudinal direction (L) at a predetermined distance from the first side seal (33) and the second side seal (34), each of which is a channel seal having no or substantially no absorbent material ( In an absorbent article (1), the channel seals (37, 38) extend within the channels (35, 36), the channel seals (37, 38) connect the upper core cover layer and the lower core cover layer (24, 25) of the core cover (5) within the channels (35, 36), and the sealing strength of the channel seals (37, 38) is higher than the sealing strength of the first side seal and the second side seal (33, 34) of the absorbent core (21), respectively. Absorbent article (1), wherein when the absorbent core (21) absorbs bodily fluids, the portion of the absorbent core (21) trapped between the channel seals (37, 38) expands, and the absorbent material placed in the portion of the absorbent core (21) positioned between the channels (35, 36) by the channel seals (37, 38) applies pressure to the first side seal (33) and the second side seal (34), causing the first side seal (33) and the second side seal (34) to burst, thereby forming a lateral expansion space for the absorbent material.

2. The absorbent article (1) according to claim 1, wherein the sealing strength of the channel seals (37, 38) is 2.5 N / 25 mm or more, and the sealing strength of the first side seal and the second side seal (33, 34) is 2.0 N / 25 mm or less.

3. The absorbent article according to claim 1 or 2, wherein the absorbent core has an hourglass shape or a T shape in a plane defined by the longitudinal direction (L) and the transverse direction (T).

4. The absorbent article according to claim 1, 2, or 3, wherein the first side seal and the second side seals (33, 34) and the channel seals (37, 38) are adhesive seals, welded seals, or a combination of adhesive seals and welded seals.

5. The absorbent article according to claim 4, wherein the first side seal (33), the second side seal (34), and each channel seal (37, 38) are adhesive seals.

6. The absorbent article according to claim 5, wherein the basis weight of the adhesive in each channel seal (37, 38) is higher than the basis weight of the adhesive in the first side seal (33) and the second side seal (34), respectively.

7. The basis weight of the adhesive in each channel seal (37, 38) is 3 g / m². ２ The above is true, and the basis weight of the adhesive in each side seal (33, 34) is 5 g / m². ２ The absorbent article according to claim 6, which is as follows:

8. The absorbent article according to any one of claims 1 to 7, wherein the core cover (5) is formed from a single continuous cover material that covers the absorbent core (21), the first side edge (26) and the second side edge (27) of the absorbent core (21) are positioned inside the corresponding first side fold and second side fold in the continuous cover material, and the first side seal and the second side seal (33, 34) are positioned laterally inward at the corresponding first and second side folds.

9. The absorbent article according to any one of claims 1 to 7, wherein the upper core cover layer (24) and the lower core cover layer (25) are separate core cover layers.

10. The absorbent article (1) comprises, in addition to the upper core cover layer (24) and the lower core cover layer (25), a liquid permeable top sheet (22) and a liquid barrier layer (23), wherein the absorbent core (21) is positioned between the liquid permeable top sheet (22) and the liquid barrier layer (23), the upper core cover layer (24) faces the liquid permeable top sheet (22), and the lower core cover layer (25) faces the liquid barrier layer (23), as described in any one of claims 1 to 9.

11. The absorbent article according to any one of claims 1 to 10, wherein the absorbent core (21) comprises 5% to 80% by weight of superabsorbent material.

12. The absorbent article according to any one of claims 1 to 11, wherein the plurality of channels (35, 36) extend spaced apart from each other and consist of two channels (35, 36) symmetrically arranged on each side of the longitudinal centerline (Lc) between the longitudinal centerline (Lc) and a corresponding one of the first side seal (33) and the second side seal (34).

13. The absorbent article according to any one of claims 1 to 12, wherein the length of each of the plurality of channels (35, 36) is in the range of 50 millimeters to 500 millimeters.

14. The absorbent article according to any one of claims 1 to 13, wherein the absorbent core (21) comprises two or more parts (51, 52, 53) having different absorption capacities.

15. The absorbent article according to claim 14, wherein, as seen in the longitudinal direction (Lc), the central part (51) of the absorbent core (21) located between the first end portion (52) and the second end portion (53) of the absorbent core (21) has a thickness greater than the thickness of the first end portion (52) and a thickness greater than the thickness of the second end portion (53).

16. The absorbent article according to claim 15, wherein the central part (51) of the absorbent core (21) has a uniform thickness, the first end portion (52) and the second end portion (53) of the absorbent core (21) each have a uniform thickness, and the central part (51) of the absorbent core (21) is separated from the first end portion (52) and the second end portion (53) respectively by corresponding first transition section (54) and second transition section (55).

17. The absorbent article according to claim 16, wherein the first end portion (52) is a front end portion (52), the first transition section (54) is a front transition section (54) having an extension in the longitudinal direction (Lc) of 5 mm to 30 mm, the second end portion (53) is a rear end portion (53), and the second transition section (55) is a rear transition section (55) having an extension in the longitudinal direction (Lc) of 20 mm to 80 mm.

18. The absorbent article according to claim 16 or 17, wherein the ratio between the thickness of the central portion (51) and the thickness of the first end portion (52) of the absorbent core (21) is in the range of 4 to 1.

5.

19. The absorbent article according to claim 16, 17, or 18, wherein the ratio between the thickness of the central portion (51) of the absorbent core (21) and the thickness of the second end portion (53) is in the range of 4 to 1.

5.

20. The absorbent article according to any one of claims 1 to 19, wherein the absorbent core has a length determined as the distance between a point on the first edge (28) where the first edge (28) intersects the longitudinal centerline (Lc) and a point on the second edge (29) where the second edge (29) intersects the longitudinal centerline (Lc), and the length of the absorbent core (21) is in the range of 300 millimeters to 700 millimeters.

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