Method for manufacturing an absorbent core for a disposable absorbent hygienic article, absorbent core, and absorbent article

Abstract

A method for manufacturing an absorbent core (142, 221) for a disposable absorbent hygienic article (201), the method comprising the steps of: providing a first core cover web (104) and introducing at least one pleat (109) into the first core cover web (104) to form a pleated first core cover web (104) having a reduced width; applying an adhesive to the pleated first core cover web (104); fitting the pleated first core cover web (104) into a recess (113) arranged on a mat former (201), the recess (113) comprising at least one channel forming element (115) arranged on a bottom surface (114) of the recess (113), causing the pleats (109) in the first core cover web (104) to at least partially unfold in the at least one channel forming element (115); The method includes the steps of: applying absorbent material (121, 122) on the first core cover web (104) in the recess (113); applying adhesive on the second core cover web (124); applying the second core cover web (124) to the first core cover web (104) and to the absorbent material (121, 122) disposed on the first core cover web (104); forming an absorbent laminate (140) comprising the absorbent material (121, 122), the second core cover web (124) and the first core cover web (104) by pressing the second core cover web (124) and the first core cover web (104) together; and forming individual absorbent cores (142) by cutting the absorbent laminate (140). Absorbent cores and absorbent articles comprising absorbent cores are also disclosed.

Description

[Technical Field]

[0001] The present disclosure relates to a method for manufacturing an absorbent core for a disposable absorbent hygienic article, the method comprising the steps of providing a first core cover web, applying an absorbent material onto the first core cover web by mat formation, and attaching a second core cover web to the first core cover web and the absorbent material, thereby sandwiching the absorbent material between the first core cover web and the second core cover web. The present disclosure further relates to an absorbent core produced according to the method, and to an absorbent article including the absorbent core. [Background technology]

[0002] In disposable absorbent articles, such as baby diapers and other articles for absorbing body fluids, such as pant-type absorbent garments, incontinence protectors, and sanitary napkins, there is a conflict between the requirements for sufficient absorbent capacity and leakage prevention and the wearer's comfort and discretion. Therefore, there is a need for highly absorbent articles that are flexible without being bulky and that conform well to the wearer's body. It is highly desirable for the wearer to not feel restricted or uncomfortable while wearing the absorbent article, yet be confident that the article is effective in preventing leakage. For adult users, it is particularly important that pant-type garments resemble regular underwear as much as possible and can be worn unobtrusively under regular tight-fitting clothing. To provide sufficient absorption capacity while maintaining a thin absorbent article, a majority of the absorbent material can be a superabsorbent material, or simply what is commonly known as a "superabsorbent." Superabsorbents can be combined with absorbent fibers (mainly cellulose pulp fibers) to form a fibrous network that contributes to distributing liquid within the absorbent core and retaining particulate superabsorbent material within the core. Superabsorbents are polymeric materials that are typically incorporated into absorbent articles in the form of fibers, particles, or granules. When superabsorbents swell to form hydrogels, they can absorb many times their own weight in fluid. Absorbent articles containing large amounts of superabsorbent material have been found to lose their initial flexibility and wearer comfort as they absorb liquid and swell. High-impact areas of absorbent articles (e.g., the crotch area of ​​a diaper, which contains a large amount of absorbent material distributed over a relatively small area) can thicken and stiffen as the article absorbs liquid. Furthermore, in disposable absorbent articles, it is important that the available absorption capacity of the absorbent material be fully utilized as much as possible to keep material consumption to a minimum when producing absorbent articles. It is therefore desirable that the full absorbent capacity of the superabsorbent material can be utilized.

[0003] WO 2021 / 215972 A1 proposes arranging channels in the form of areas free of absorbent material in an absorbent core sandwiched between liquid-permeable upper and lower core cover layers, the upper and lower core cover layers being attached to one another in at least two spaced-apart attachment zones in the areas free of absorbent material.

[0004] The attachment between the upper core cover layer and the lower core cover layer in the absorbent-free area prevents the absorbent material from moving freely within the absorbent core and from being redistributed in an uncontrolled and undesirable manner between the upper core cover layer and the lower core cover layer. During use of the absorbent article, the absorbent core will absorb body fluids and swell. The attachment zones where the upper and lower core cover layers are connected to each other form a restriction means that limits swelling in the thickness direction of the absorbent article by preventing the upper and lower core cover layers from moving freely away from each other. As the absorbent core absorbs fluid and swells, the absorbent material on either side of the absorbent-free area can expand in the transverse direction of the absorbent article into the portion of the absorbent-free area located between the attachment zones.

[0005] While the absorbent core of WO2021 / 215972A1 has been found to improve utilization of the available absorbent capacity in the absorbent core, the expansion space for the swelling absorbent material is limited by the available space in the absorbent-free areas.

[0006] Moreover, channels are generally disposed within the absorbent core to promote fluid acquisition and distribution within the core. In the absorbent core of WO 2021 / 215972 A1, the channels formed by areas without absorbent material at least partially disappear over time because the absorbent material swells into the channels, reducing their ability to receive and distribute bodily fluids.

[0007] The absorbent core is generally sandwiched between a lower core cover layer and an upper core cover layer, and the core is mat-formed onto the lower core cover layer and then covered with the upper core cover layer. Channels can be formed in the core by placing raised channel-forming elements on the mat-forming surface of a mat-former and applying the lower core cover layer over the channel-forming elements. The lower core cover layer is conformed to the raised channel-forming elements, and it has been found that there is a risk that the lower core cover layer will be torn by a corner or edge on the raised channel-forming elements while being applied to the channel-forming elements. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] WO2021 / 215972A1 Summary of the Invention [Problem to be solved by the invention]

[0009] An object of the present disclosure is to provide an improved method for manufacturing an absorbent core having one or more channels disposed therein. A further object of the present disclosure is to provide an absorbent core having an improved ability to utilize the available absorbent capacity of the absorbent material within the core. Yet a further object of the present disclosure is to provide an absorbent core having an improved ability to utilize the available absorbent capacity of the absorbent material within the core. [Means for solving the problem]

[0010] The above and further objects can be achieved by a method according to claim 1, an absorbent core according to claim 14 and an absorbent article according to claim 20. Variations of the present disclosure are set out in the dependent claims and in the following description.

[0011] The absorbent articles referred to herein can be, for example, wearable disposable absorbent articles in the form of open diapers, pant diapers, belt diapers, incontinence garments, and feminine hygiene garments, as well as disposable absorbent inserts, such as incontinence shields or sanitary napkins, that are worn inside support garments (such as support pants or regular underwear). Such articles are used to absorb, distribute, and store various types of body exudates while providing the wearer with a high level of comfort and dryness during wear.

[0012] A method for making an absorbent core for a disposable absorbent sanitary article as disclosed herein comprises: - providing a first core cover web having a first surface and a second surface, and advancing the first core cover web in a machine direction, the first core cover web having side edges extending in the machine direction, a first core cover width defined in a cross machine direction between the side edges of the first core cover web, the cross machine direction being perpendicular to the machine direction; - reducing a width of the first core cover web by introducing at least one pleat into the first core cover web, the at least one pleat extending in the machine direction between side edges of the first core cover web to form a pleated first core cover web, the pleated first core cover web having a second core cover width between the side edges of the pleated first core cover web, the second core cover width being smaller than the first core cover width; - applying an adhesive to a first surface of the pleated first core cover web; - advancing the pleated first core cover web onto a mat-forming surface of a mat-former, the mat-former having a recess disposed on the mat-forming surface, the recess having an air-permeable bottom surface and including at least one channel-forming element disposed above and protruding from the bottom surface of the recess; - fitting the pleated first core cover web to the recess and at least one channel-forming element on a bottom surface of the recess, with a second surface of the first core cover web facing the bottom surface of the recess, causing the pleats in the first core cover web to at least partially unfold in the at least one channel-forming element; - applying an absorbent material onto a first surface of the first core cover web within the recess; - providing a second core cover web having a first surface and a second surface; - applying an adhesive onto a first surface of a second core cover web; - applying a second core cover web to the first core cover web and to an absorbent material disposed on the first core cover web; - forming an absorbent laminate including the absorbent material, the second core cover web, and the first core cover web by pressing the second core cover web together; - cutting the absorbent laminate in the cross machine direction to form individual absorbent cores; Includes.

[0013] Each individual absorbent core formed by the methods disclosed herein comprises an absorbent material sandwiched between a portion of the second core cover web and a portion of the first core cover web.

[0014] The one or more pleats formed in the first core cover web before advancing the first core cover web onto the mat-forming surface serve to reduce stresses in the first core cover material as it is applied to the mat-forming surface and conforms to the recess in the mat-forming surface and the at least one channel-forming element on the bottom surface of the recess, thereby reducing stresses in the first core cover web and improving conformance of the core cover web to the one or more channel-forming elements while reducing or even eliminating the risk of tearing the first core cover web.

[0015] The pleats in the pleated first core cover web are at least partially developed when the pleated first core cover web is fitted to the contoured bottom of the mat-forming recess on the mat-forming surface. The pleats can even disappear completely, so that they are not visible in the final core in areas of the core where channels are formed.

[0016] In the mat-forming process, a vacuum is applied to the air-permeable recesses in the mat-forming surface, sucking the first core cover web into the recesses in the mat-forming surface and causing the first core cover web to conform to one or more channel-forming elements at the bottom of the continuous recesses.

[0017] In the methods as disclosed herein, two or more pleats can be introduced into the first core cover web (e.g., three or more pleats, four or more pleats, etc.), each pleat can correspond to a channel-forming element in a mat-forming recess, or a pair of pleats can correspond to a channel-forming element in a recess disposed in the mat-forming surface.

[0018] A pleat, as used herein, is formed by two folds generated in the first core cover web and having a cross-sectional shape of either a Z or an inverted Z. Two pleats arranged side by side, consisting of a Z-shaped pleat and an inverted Z-shaped pleat, together form an Ω-shaped configuration.

[0019] Pleating the first core cover web can reduce the width of the first core cover web such that the second core cover width can be 65% to 97% of the first core cover width. The width of all pleats together can be 3% to 35% of the core width.

[0020] In the methods as disclosed herein, the mat-forming machine can include a rotatable mat-forming drum, the mat-forming surface being a peripheral surface of the mat-forming drum, and the recesses being disposed in the peripheral surface of the mat-forming drum.

[0021] Alternatively, the mat former can be a moving conveyor with a mat-forming surface having recesses disposed therein.

[0022] The one or more channel-forming elements can form corresponding areas of absorbent material that are free or substantially free of absorbent material, such that the first and second core cover webs can be brought into direct contact with one another and bonded together in the one or more absorbent-free areas, whereby distinct channels can be formed in the absorbent core along the attachment between the first and second core cover webs.

[0023] The attachment between the second core cover web and the first core cover web, which are positioned along the channel-forming element, stabilizes the absorbent core and prevents the absorbent material from moving freely and being redistributed in an uncontrolled and undesirable manner within the space bounded by the first and second core cover layers.

[0024] During use of an absorbent article comprising an absorbent core produced according to the method disclosed herein, the absorbent core will absorb and swell body fluids. The bond between the upper and lower core cover layers of the absorbent core prevents the upper and lower core cover layers from freely moving apart, thereby limiting swelling of the absorbent core through its thickness. However, one or more pleats deployed in the upper or lower core cover layer reduce the restraining force on the absorbent material trapped between the upper and lower core cover layers, providing an absorbent core with improved swelling capacity, thereby improving utilization of the absorbent material's absorptive capacity.

[0025] After application of adhesive to the second core cover web, the second core cover web can be advanced onto the rotating wheel with the second surface of the second core cover web facing the rotating wheel. A first surface of the second core cover web can be attached to the first surface of the first core cover web and to the absorbent material disposed over the first core cover web in the recesses in the mat-forming surface of the mat former by pressing the second core cover web and the first core cover web together at a nip between the rotating wheel and the mat-forming surface.

[0026] As described herein, the mat-forming surface can be a mat-forming surface on a rotating mat-forming drum or a mat-forming surface on a moving conveyor.

[0027] The attachment between the upper and first core cover webs and the absorbent core can alternatively be performed in a stand-alone unit after the mat former.

[0028] In the methods as disclosed herein, the recesses in the mat-forming surface can be continuous recesses. The recesses can be continuous recesses formed in the peripheral surface of the mat-forming drum such that the continuous recesses extend around the periphery of the mat-forming drum.

[0029] At least one channel-forming element at the bottom of the successive recesses can be composed of 2 to 15 element parts, the element parts being equidistantly distributed around the periphery of the mat-forming drum. When two channel-forming elements are disposed at the bottom of the successive recesses, the element parts of the two channel-forming elements are arranged in 2 to 15 pairs, which are equidistantly distributed around the periphery of the mat-forming drum. After forming the absorbent laminate including the upper and first core cover webs and the absorbent core sandwiched therebetween, the absorbent laminate is cut in the cross-machine direction between the element parts in a step of forming individual absorbent cores.

[0030] The number of channel-forming element parts corresponds to the number of cores formed on the mat-forming drum during one rotation of the mat-forming drum.

[0031] Alternatively, the recess in the peripheral surface of the mat-forming drum can be one of a plurality of recesses in the peripheral surface of the mat-forming drum.

[0032] In the methods disclosed herein, two or more channel-forming elements can be positioned side-by-side on the bottom surface of a recess in the mat-forming surface, each of the two or more channel-forming elements extending in the machine direction.

[0033] In the method disclosed herein, the absorbent material can include cellulose pulp fibers and a superabsorbent material. The cellulose pulp fibers and the superabsorbent material can be applied as a mixture onto the first surface of the first core cover web within the recesses in the mat-forming surface. The mixture of cellulose pulp fibers and the superabsorbent material can be a homogeneous mixture. The superabsorbent material can comprise 5% to 80% by weight of the mixture.

[0034] In the method as disclosed herein, adhesive can be uniformly distributed on the first surface of the pleated first core cover web, and adhesive can be uniformly distributed on the first surface of the second core cover web.

[0035] Since the adhesive is applied after the pleats are formed, no adhesive is applied inside the pleats, thereby uniformly applying the adhesive to the first surface of the pleated first core cover web, resulting in the adhesive being selectively placed on the first surface of the core cover web after unfolding the first core cover web.

[0036] The adhesive can be selectively distributed onto the first surface of the first core cover web by applying adhesive to the first surface of the first core cover web after pleating the first core cover web and / or by selectively applying adhesive to the first core cover web before pleating the first core cover web, such that no adhesive is applied to areas of the first core cover web corresponding to the location of the at least one channel-forming element, allowing one or more pleats formed in the first core cover web to unfold over the at least one channel-forming element.

[0037] The adhesive can be selectively distributed on the first surface of the second core cover web to affect bonding only where the second core cover web is in contact with the first core cover web, and moreover, a higher concentration of adhesive is applied to the first surface of the second core cover web in areas corresponding to the location of the at least one channel-forming element than in other parts of the second core cover web.

[0038] The adhesive can be applied to the first and second core cover webs by any suitable method as known in the art (eg, slot coating, spraying, meltblowing, etc.).

[0039] The present disclosure further relates to an absorbent core that may be produced according to a method as disclosed herein, the method comprising the steps of reducing a width of the first core cover web by introducing at least one pleat into the first core cover web to form a pleated first core cover web; applying adhesive to the pleated first core cover web; and fitting the pleated first core cover web into a recess disposed on a mat former, the recess including at least one channel forming element, the at least one channel forming element being disposed on a bottom surface of the recess, wherein the pleats in the first core cover web The method includes the steps of causing at least partial expansion in at least one channel-forming element, applying an absorbent material onto the first core cover web in the recess, applying adhesive onto the second core cover web, applying the second core cover web to the first core cover web and to the absorbent material disposed on the first core cover web, forming an absorbent laminate including the absorbent material, the second core cover web, and the first core cover web by pressing the second core cover web and the first core cover web together, and forming individual absorbent cores by cutting the absorbent laminate.

[0040] In an absorbent core as disclosed herein, the first core cover web can form the upper core cover layer and the second core cover web can form the lower core cover layer.

[0041] Alternatively, the first core cover web can form the lower core cover layer and the second core cover web can form the upper core cover layer.

[0042] The absorbent core has a length in the longitudinal direction and a width in the transverse direction, the transverse direction being perpendicular to the longitudinal direction, and includes an upper core cover layer, a lower core cover layer, and an absorbent material sandwiched between the upper core cover layer and the lower core cover layer, and the absorbent core includes at least one channel in the absorbent material. When viewed in the longitudinal direction, the absorbent core includes a first part and a second part, the at least one channel is disposed entirely in the first part of the absorbent core, and one or more pleats are disposed in the upper core cover layer or the lower core cover layer in the second part of the absorbent core, the one or more pleats extending in the longitudinal direction.

[0043] The folds disposed in the upper or lower core cover layer form one or more expandable pleats in the core cover layer, providing an absorbent core with improved capacity to accommodate swelling absorbent material (e.g., a mixture of cellulose fibers and superabsorbent material). The one or more expanded pleats increase the available swelling space between the upper and lower core cover layers in the area of ​​the core where the at least one channel is located. When the absorbent material in the absorbent core absorbs liquid and swells, the one or more expanded pleats in the lower core cover layer allow the absorbent material to expand with less restriction than previously known absorbent cores. The expanded pleats provide expansion space in the thickness direction of the absorbent core, which is generally perpendicular to the length and width directions of the absorbent core. The expandable upper or lower core cover layer allows at least one channel in the absorbent core to remain intact, or at least substantially intact, during swelling of the absorbent material therein. When the absorbent core is incorporated into an absorbent article, the at least one channel is capable of retaining its liquid acquisition and distribution properties throughout the use of the absorbent article, even as the absorbent material in the absorbent core absorbs liquid and swells.

[0044] The absorbent core may further include a third part when viewed in the longitudinal direction of the core, wherein the first part of the absorbent core is positioned between the second and third parts of the absorbent core, and one or more pleats are positioned in the upper core cover layer or in the lower core cover layer in the third part of the absorbent core, and one or more pleats in the upper or lower core cover layer in the third part of the absorbent core are aligned with corresponding ones of the one or more pleats in the upper or lower core cover layer in the second part of the absorbent core.

[0045] When referring to the dimensions of components in absorbent articles and absorbent cores as disclosed herein, unless it is expressly stated that the dimensions are determined in a wet state after absorption of liquid, the dimensions are determined when the absorbent articles and absorbent cores are in a dry state (i.e., before absorbing any liquid).

[0046] The upper and lower core cover layers may be constructed of a nonwoven material.

[0047] Suitable nonwoven materials can be, for example, spunbond nonwoven materials or nonwoven materials that include a combination of spunbond and meltblown layers (e.g., in an SMS configuration). 2 from 12 g / m 2 It is possible for the sheet to have a basis weight on the order of .

[0048] The core-cover layer can have a common boundary along the side edges of the absorbent core or can have a generally common boundary.

[0049] The absorbent material can include or consist of a mixture of cellulose pulp fibers and superabsorbent material. The mixture can be a generally homogeneous mixture or can contain different percentages of superabsorbent and pulp fibers in different parts of the absorbent core. For example, the percentage of superabsorbent material can be higher in a longitudinally intermediate portion of the absorbent core, corresponding to a first part of the absorbent core in which one or more channels are disposed, as disclosed herein, and lower in end portions of the absorbent core, corresponding to one or both of the first and third parts of the absorbent core.

[0050] The superabsorbent material may be present in the mixture in an amount of from 5% to 80% by weight of the mixture.

[0051] The absorbent core may have a rectangular shape with longitudinally extending side edges and transversely extending end edges, and the lower core cover layer has a greater transverse width than the upper core cover layer, the width of the core cover layer being the width of the core cover layer in its unfolded, completely flat state.

[0052] The absorbent core can have a rectangular shape or any other suitable shape as known in the art (e.g., hourglass shape, dogbone shape, T-shape, H-shape, etc.) A rectangular absorbent core can have the advantage of being easy to manufacture and easy to enclose in a core cover.

[0053] Superabsorbent materials suitable for use in the absorbent core disclosed herein are well known in the field of absorbent articles and are composed of water-swellable and water-insoluble materials that can absorb large amounts of fluid when forming a hydrogel. The absorbent core can contain superabsorbent materials in the form of fibers or particles of absorbent polymer materials. For example, the superabsorbent material can be a surface-crosslinked, partially neutralized polyacrylate. The superabsorbent material (e.g., superabsorbent fibers or particles) can be mixed with other absorbent materials or one or more liquid-acquisition materials (e.g., cellulose fluff pulp, etc.).

[0054] The methods, and absorbent cores and absorbent articles as disclosed herein are further described hereinafter with reference to the accompanying drawings. [Brief explanation of the drawings]

[0055] [Figure 1] FIG. 1 is a schematic diagram of a method as disclosed herein. [Figure 2] FIG. 1 is a top view of a first core cover web being applied to a mat-forming surface in a prior art manner. [Figure 3] 3 is a cross-section through the first core cover web and mat-forming surface of FIG. 2 taken along line III-III. [Figure 4] FIG. 2 is a top view of a first core cover web being applied to a mat-forming surface in a manner as disclosed herein. [Figure 5] FIG. 5 is a cross-section through the first core cover web and mat-forming surface of FIG. 4 taken along line VV. [Figure 6] 1 is a plan view of an unfolded absorbent pant-type article with an absorbent assembly and open side seams as viewed from the inner surface of the pant-type article. [Figure 7]7 is an enlarged view of the absorbent assembly in the pant-type article of FIG. 6, with the absorbent core enclosed within the core cover. [Figure 8] 7 shows the pant-type article of FIG. 6 with the side seams closed and unfolded, as the pant-type article would appear before use. DETAILED DESCRIPTION OF THE INVENTION

[0056] The different aspects of the present disclosure will be described more fully hereinafter with reference to the accompanying drawings. However, the embodiments disclosed herein may be realized in many different forms and should not be construed as limited to the aspects described herein. While the absorbent sanitary article shown in the figures is a pant-type absorbent article, it should be understood that the methods disclosed herein are applicable when forming any type of disposable absorbent sanitary article as disclosed herein, including an absorbent core with a swellable absorbent material sandwiched between an upper core cover layer and a lower core cover layer. The absorbent core as described herein can be used in any disposable absorbent article for absorbing urine, feces, and / or vaginal secretions.

[0057] It should be understood that the drawings are schematic and that individual elements (eg, layers of material, etc.) are not necessarily drawn to scale.

[0058] Referring initially to Figure 1, there is shown a schematic diagram of a method for producing an absorbent core for use in disposable absorbent sanitary articles.

[0059] The method shown in Figure 1 is carried out using a mat-forming machine 101 including a rotatable mat-forming drum 102. A first core cover web 104 having a first surface 105 and a second surface 106 is advanced in the machine direction MD.

[0060] The first core cover web 104 is passed through a pleating unit 108 where two pleats 109 are formed in the first core cover web 104, as seen in FIG. 4 , with the pleats 109 extending in the MD between the side edges of the first core cover web 104. While two pleats are shown and described herein, it should be understood that any suitable number of pleats (e.g., one pleat, three pleats, or more pleats) can be formed in the first core cover web 104 by the pleating unit 108. By pleating the first core cover web 104, the width w of the first core cover web 104 is reduced such that the second width w2 of the pleated first core cover web 104′ is smaller than the first width w1 of the unpleated first core cover web 104. The widths w1, w2 of the unpleated and pleated first core cover webs 104, 104' are measured between the side edges 111 of the first core cover web 104 in the cross machine direction CD perpendicular to the MD, as shown in FIG.

[0061] In a next step, an adhesive (e.g., a liquid adhesive) is applied to the first surface 105 of the pleated first core cover web 104' by a first adhesive applicator 110. After application of the adhesive, the pleated first core cover web 104' is advanced onto a mat-forming surface 112 on a rotatable mat-forming drum 102 of a mat former 101. The mat-forming drum 102 has a recess 113 disposed on the mat-forming surface 112 (see FIGS. 4 and 5 ), the recess 113 having a bottom surface 114 and including two channel-forming elements 115. The channel-forming elements 115 are disposed on and protrude from the bottom surface 114 of the recess 113. With respect to the pleats 109 in the first core cover web 104, the number of channel-forming elements on the bottom surface 114 of the recess 113 can be varied as disclosed herein. Thus, a single channel-forming element may be used, or three or more channel-forming elements may be used. The number of channel-forming elements 115 may correspond to the number of pleats 109 in the first core cover web 104, and the locations of the pleats 109 in the first core cover web 104 may be synchronized with the placement of the channel-forming elements 115.

[0062] The pleated first core cover web 104' is then sucked into the recess 113 by a vacuum force V, which is applied through the air-permeable bottom surface 114 of the recess 113 from the inside of the rotating mat-forming drum 102.

[0063] 5, the pleated first core cover web 104' as seen in the upper part of the figure is moved in the direction of arrow A into the recess 113, conforming to the shape of the recess 113 and to the two channel-forming elements 115 therein, with the second surface 106 of the first core cover web facing the bottom surface 114 of the recess 113. During this process, the pleats 109 in the core cover web 104 unfold to cover the bottom 114 of the recess and the channel-forming elements 115, as seen in the lower portion of FIG. The pleated core cover web 104' is drawn into the recesses 113 by a vacuum force V applied from inside the rotating mat-forming drum 102, causing the pleats 109 in the pleated first core cover web 104' to unfold in the channel-forming element 115 and to easily conform to the shape of the channel-forming element 115 due to the excess material that becomes available as the pleats 109 unfold. The pleats in the first core cover web 104 allow the first core cover web 104 to conform to the shape of the protruding channel-forming element 115 without undue stretching or tensioning of the first core cover web 104.

[0064] This differs from the prior art application of a first core cover web 104 to a recess 113 having a channel-forming element 115, as shown in Figures 2 and 3. In the prior art application of the first core cover web 104, the first core cover web 104 is sucked into the recess 113 by a vacuum force V, causing increased stress in the material at the relatively sharp edges and corners of the channel-forming element 115. Tension in the first core cover web material can cause the first core cover web to tear or puncture. Additionally, the prior art first core cover web 104 has a lower ability to conform to the shape of the recess 113, meaning that the non-conforming parts of the first core cover web 104 reduce the space available for filling the recess with absorbent material, as shown in Figure 3.

[0065] An absorbent material is then applied onto the first surface 105 of the first core cover web in the recesses 113 on the mat-forming surface 112 of the rotatable mat-forming drum 102. In Figure 1, the application of the absorbent material is illustrated by an air-laying unit 120 in which air-entrained wood pulp 121 is mixed with superabsorbent material 122 (e.g., superabsorbent particles or fibers) and the mixture is drawn into the recesses 113 that are covered by the first core cover web 104.

[0066] After application of the absorbent material, a second core cover web 124 having a first surface 125 and a second surface 126 is provided, and an adhesive (e.g., a liquid adhesive) is applied to the first surface 125 of the second core cover web 124 by a second adhesive applicator 130. The second core cover web 124 is advanced onto the rotating wheel 131 with the second surface 126 of the second core cover web 124 facing the rotating wheel 131. The second core cover web 124 is applied to the mat-forming surface 112 of the rotatable mat-forming drum 102 by the rotating wheel 131, covering the first core cover web 104 in the recess 113 and the absorbent materials 121, 122 disposed on the first core cover web 104.

[0067] The first surface 125 of the second core cover web 124 is attached to the first surface 105 of the first core cover web 104 and to the absorbent materials 121, 122 disposed on the first core cover web 104 in the recess 113 in the mat-forming surface 112 of the mat-forming drum 102 by pressing the second core cover web 124 and the first core cover web 104 together in the nip 135 between the two rollers, forming an absorbent laminate 140 including the absorbent materials 121, 122, the second core cover web 124, and the first core cover web 104. Pressing the second core cover web 124 and the first core cover web 104 together places the core cover webs in direct or substantially direct contact with each other in areas created in the channel forming elements 115 that are generally free of absorbent material and in matching areas of the second core cover web 124 and the first core cover web 104 that are positioned outside the recesses 113.

[0068] Alternatively, or in addition, forming the absorbent laminate 140 can include pressing the second core cover web and the first core cover web together in the nip 134 between the rotating wheel 131 and the rotating mat-forming drum 102.

[0069] After forming the absorbent laminate 140, individual absorbent cores 142 are formed by cutting the absorbent laminate 140 in the cross machine direction in a cutting unit 141.

[0070] Although the method as disclosed herein has been illustrated using a mat-forming machine 101 having a rotating mat-forming drum 102, it should be understood that the method as disclosed herein is equally applicable to mat formation on a moving conveyor.

[0071] The recess 113 in the mat-forming surface 112 of the mat-forming drum 102 can be a continuous recess extending around the entire periphery of the mat-forming drum 102, or the recess can be one of a plurality of recesses distributed equidistantly around the periphery of the mat-forming drum 102.

[0072] As disclosed herein, each channel-forming element 115 in the continuous recess can be composed of multiple element parts, with the element parts being distributed equidistantly around the periphery of the mat-forming drum 102. When two channel-forming elements are arranged side-by-side, the element parts are arranged in pairs around the periphery of the mat-forming drum 102. When cutting the absorbent laminate 140 to form the individual absorbent cores 142, the absorbent laminate 140 is cut in the cross-machine direction CD between the element parts. Thus, the number of channel-forming element parts in each channel-forming element 115 corresponds to the number of cores formed on the mat-forming drum during one revolution.

[0073] The adhesive can be evenly distributed on the first surface 105 of the pleated first core cover web 104'. Similarly, the adhesive can be evenly distributed on the first surface of the second core cover web 124.

[0074] Alternatively, adhesive can be selectively dispensed onto one or both of the core cover webs 104, 124 to create any desired bond pattern.

[0075] With reference to Figure 6, it should be understood that the pant-type article shown in the figure is a simplified article and that the article can contain additional features (e.g., barrier cuffs, wetness indicators, etc.). It should also be understood that the waist elastics disclosed herein are optional, or any other suitable type of waist elastic can be used. The side seams can be reclosable side seams, and the pant-type article can be provided with fastening elements to provide reclosability of the side seams.

[0076] The pant-type article 201 of Figure 6 is in the form of a pant-type incontinence article for an adult user. The pant-type article 201 is shown in Figure 6 in an unfolded, flat condition, with all elastic elements in a fully extended state. The pant-type article has a longitudinal direction L and a transverse direction T, the transverse direction T being perpendicular to the longitudinal direction, and a longitudinal centerline Lc extending in the longitudinal direction L.

[0077] The pant-type article 201 is viewed from the inner surface, which is the surface that faces the wearer's body when the article is being worn, and is opposite the outer garment-facing surface of the pant-type article 201.

[0078] The pant-type article 201 includes a front portion 203, a back portion 204, and an absorbent assembly 220, which is positioned in the crotch region 206 of the pant-type article 201 and extends forward over the front portion 203 and rearward over the back portion 204 in the longitudinal direction L. The absorbent assembly 220 in the pant-type article shown in the figures is a separately manufactured component that includes an absorbent core 221, which includes an absorbent material sandwiched between an upper core cover layer 224 and a lower core cover layer 225. The absorbent core 221 is further enclosed between a liquid-permeable topsheet 222 and a liquid barrier layer 223. The absorbent core 221 is positioned between the topsheet 222 and the liquid barrier layer 223, with the upper core cover layer 224 facing the liquid topsheet 222 and the lower core cover layer 225 facing the liquid barrier layer 223.

[0079] The absorbent articles disclosed herein are not limited to absorbent articles having an absorbent core that is applied to the article as a component of a prefabricated absorbent assembly that already includes a topsheet and a liquid barrier layer.

[0080] The front portion 203 has a front waist edge 207 extending in the transverse direction T and a pair of front side edges 208, 209 extending in the longitudinal direction L. The back portion 204 has a back waist edge 210 extending in the transverse direction T and a pair of back side edges 211, 212 extending in the longitudinal direction L.

[0081] The first front side edge 208 is joined to the first back side edge 211 at a first side seam 214, and the second front side edge 209 is joined to the second back side edge 212 at a second side seam 215, creating a pant-type article 201 having a waist opening 216, a first leg opening 217, and a second leg opening 218, as shown in FIG. 8.

[0082] The side seams 214, 215 of the pant-type article 201 can generally be band-shaped joints, which are formed by ultrasonic welding or heat welding. In order to be strong enough to withstand the forces to which the pant-type article 201 is subjected while the article is being worn, and to allow for sufficient production tolerances, the side seams generally have a width on the order of 5 to 10 millimeters. It is also known to make side seams having widths less than 5 mm.

[0083] It is generally desired that soiled pant-type articles be easily removable without having to pull the article down the user's legs, and therefore side seams are generally made so that they are breakable by manual force, allowing the user or caregiver to pull the side seams apart before removing the soiled pant-type article.

[0084] A waist opening 216 is defined by the front waist edge 207 and the back waist edge 210. A first leg edge 219' defines a first leg opening 217, and a second leg edge 219" defines a second leg opening 218.

[0085] The absorbent assembly 220 is shown in more detail in Figure 7 and has a generally hourglass shape. The absorbent core 221, enclosed between a liquid pervious topsheet 222 and a liquid barrier layer 223, has a rectangular shape with first and second side edges 226, 227 and first and second end edges 228, 229. The first and second side edges 226, 227 of the absorbent core 221 have a major extent in the longitudinal direction L, and the first and second end edges 228, 229 have a major extent in the transverse direction T.

[0086] The absorbent core 221 has a length in the longitudinal direction L and a width in the transverse direction T. The absorbent core includes an upper core cover layer 224 and a lower core cover layer 225, and an absorbent material sandwiched between the upper core cover layer 224 and the lower core cover layer 225.

[0087] The absorbent core 221 can be divided into a first core part 251, a second core part 252, and a third core part 253, and the first core part 251 is disposed between the second core part 252 and the third core part 253. The first core part 251 is the central part 251 of the absorbent core 221 as seen in the longitudinal direction L of the absorbent core 221, the second core part 252 is the front end part 252 of the absorbent core 221, and the third core part 253 is the rear end part 253 of the absorbent core 221.

[0088] Two pleats 209 are disposed in the lower core cover layer 225 in each of the second core part 252 and the third core part 253. The pleats 209 in the third or rear part 253 of the absorbent core 221 are aligned with corresponding pleats 209 in the second or front part 252 of the absorbent core 221. This arrangement is the result of the manufacturing process for the absorbent core 221, which is described herein, for example, with reference to Figures 1, 4, and 5, that produces an absorbent core having deployed pleats in the first core part 251 in which longitudinally extending channels 235, 236 are disposed, and remaining pleats 209 in the parts 252, 253 of the core 221 in which the channels are not formed.

[0089] In the illustrated absorbent core 221, the first core cover web 104 forms the lower core cover layer 225. However, it should be understood that it is equally viable to use the first core cover web 104 as the upper core cover layer in an absorbent core as disclosed herein. In such a case, the remaining pleats would be in the upper core cover layer.

[0090] When measuring the widths of the upper core cover layer 224 and the lower core cover layer 225 in a fully flat, unfolded state, the lower core cover layer in the absorbent core 221 shown in the figure has a greater width in the transverse direction T than the upper core cover layer 224.

[0091] The first channel 235 and the second channel 236 are disposed within the absorbent core 221 and extend in the longitudinal direction L on either side of the longitudinal centerline Lc and at a predetermined distance from each of the first and second side edges 226, 227 of the absorbent core 221. The channels 235, 236 are free or substantially free of absorbent material. The first and second channels are disposed entirely within the first central part 251 of the absorbent core 221.

[0092] The upper core cover layer 224 and the lower core cover layer 225 are connected to one another by a first side seal 233 extending along a first side edge 226 of the absorbent core 221 and by a second side seal 234 extending along a second side edge 227 of the absorbent core 221. In addition, the upper and lower core cover layers 224, 225 are connected by a first channel seal 237 in a first channel 235 and a second channel seal 238 in a second channel 236.

[0093] The channel seals 237, 238 are permanent or substantially permanent seals that do not rupture under normal use and handling of the absorbent article. Thus, the channel seals 237, 238 remain intact or substantially intact even after the absorbent article has absorbed liquid. The side seals 233, 234 can be permanent seals, or they can be rupturable seals with low seal strength such that the side seals 233, 234 rupture under the influence of forces exerted on them as the absorbent material in the absorbent core 221 absorbs fluid and expands.

[0094] As disclosed herein, the side seals 233, 234 and channel seals 237, 238 are adhesive seals formed by adhesive applied to the facing surfaces of the second core cover web 124 and the first core cover web 104 in a manner as disclosed herein.

[0095] Depending on the type and size of the absorbent article in which one or more channels as disclosed herein are disposed, the length of the channels 235, 236 can range from 50 millimeters to 500 millimeters.

[0096] In pant-type absorbent articles for incontinent adult users (such as the illustrated absorbent article 201), the channels 235, 236 are preferably located in the crotch region 206 of the article, which is the narrow portion of the article that will be placed against the user's crotch when the article is worn. The narrow crotch region 206 of the absorbent article is the portion of the article that will receive the majority of excreted body fluids (e.g., urine). The crotch region 206 must have good absorbent properties in terms of liquid acquisition, liquid distribution, and absorption capacity. The channels 235, 236 in the absorbent core 221 contribute to rapid liquid acquisition and promote fluid distribution by directing fluid flow toward the front and rear regions 203, 204 of the absorbent article 201. In the illustrated absorbent article 201, the length of the channels 235, 236 substantially corresponds to the length of the crotch region 206 and can typically be on the order of 100 to 250 millimeters.

[0097] In wearable incontinence articles (such as open diapers and pant diapers), the channels will typically have lengths on the order of 30% to 50% of the total length of the absorbent core. In smaller absorbent articles (such as incontinence shields and sanitary napkins), the channels can extend almost to the ends of the absorbent core (such as, for example, up to 80% of the total length of the absorbent core).

[0098] In order to enhance the absorbent capacity in the narrow crotch region 206 of the absorbent article 201, the central first part 251 of the absorbent core 221 has a greater thickness than the front end part 252 and the rear end part 253 of the absorbent core 221.

[0099] The central part 251 of the absorbent core 221 is shown to have a uniform thickness, and the end parts 252, 253 each have a uniform thickness, with the central part 251 of the absorbent core 221 separated from the end parts 252, 253 by front and rear transition zones 254, 255. The thickness of the absorbent core 221 decreases linearly in the transition zones 254, 255 from the central part 251 of the absorbent core 221 to the end parts 252, 253 of the absorbent core 221. As shown in Figure 7, the pleats 209 are also present in the lower core cover layer 225 below the transition zones 254, 255 because the channels 235, 236 do not extend into the transition zones 254, 255.

[0100] In the figures, the absorbent core 221 is shown having a rectangular shape defined by the shape of the core-cover layers, and the absorbent material between the core-cover layers is shown arranged in a three-dimensional profile in the thickness direction, with a generally hourglass shape in the L / T plane. However, it should be understood that the absorbent core 221 can be cut into shapes other than a rectangular shape (e.g., an hourglass shape). Similarly, the absorbent material can be arranged in configurations other than those shown in the figures. Thus, the three-dimensional profile of the absorbent core shown in FIG. 7 is non-limiting to the absorbent core as disclosed herein; any planar and three-dimensional shape can be used for the overall core and for the absorbent material sandwiched between the core-cover layers.

[0101] In a planar or substantially planar absorbent core, the absorbent capacity of the absorbent core may differ in different parts of the core as a result of different amounts of superabsorbent material being disposed in different parts of the core.

[0102] The absorbent core 221 as disclosed herein can include any material suitable for absorbing excreted bodily wastes, such as, for example, cellulosic fluff pulp and highly absorbent polymers (superabsorbents). The absorbent assembly 220 can include additional absorbent components, such as a tissue layer, an absorbent foam material, including a hydrogel foam material, or an absorbent nonwoven material. The absorbent assembly can include nonabsorbent components (e.g., reinforcing elements, shaping elements, binders, etc.). Various types of liquid-accepting and liquid-distribution elements can also be included in the absorbent assembly.

[0103] The absorbent core 221 preferably includes superabsorbent material (e.g., superabsorbent material in an amount of 5% to 80% by weight of the absorbent material) at least in the central part 251 of the absorbent core 221. As described herein, the superabsorbent content may be lower in the front end parts 252 and / or the rear end parts 253 of the absorbent core 221 than in the central part 251 of the absorbent core 221, or may be the same in all parts of the absorbent core 221.

[0104] Superabsorbent materials are polymeric materials and can be in the form of particles, granules, fibers, flakes, and the like.

[0105] As disclosed herein, the absorbent material in the absorbent core 221 can include or be composed of a mixture of absorbent cellulose fibers (e.g., cellulose pulp fibers, etc.) and superabsorbent material.

[0106] The high amount of superabsorbent material in the absorbent core allows for the production of thin, discrete absorbent articles while providing high absorbent capacity and the ability to chemically bind and immobilize absorbed fluids, resulting in an absorbent article with high leak resistance and a dry inner surface even after absorbing large amounts of fluid.

[0107] Superabsorbent materials absorb liquids by swelling and forming an aqueous gel. To fully utilize the absorbent capacity of the superabsorbent material, the absorbent article must provide sufficient expansion space for the superabsorbent material. Because the absorbent core is captured between the upper core cover layer 224 and the lower core cover layer 225, the swelling of the superabsorbent material is limited by the available expansion space between the core cover layer 224 and the core cover layer 225.

[0108] The liquid-permeable topsheet 222 can include or be composed of a nonwoven material. Other suitable topsheet materials include tow fibers, porous foams, apertured plastic films and laminates, and combinations of such materials. Materials optimal for topsheet materials are soft and non-irritating to the skin, are easily penetrated by bodily fluids, and exhibit low rewet.

[0109] The liquid barrier layer 223 can be composed of a thin plastic film (e.g., polyethylene or polypropylene film), a nonwoven material coated with a liquid-impermeable material, a hydrophobic nonwoven material that resists liquid penetration, or a laminate of a plastic film and a nonwoven. The liquid barrier layer material can be breathable to allow vapor to escape from the absorbent body portion while still preventing liquid from passing through the liquid barrier layer material.

[0110] The topsheet and liquid barrier layer can be connected to one another by, for example, adhesive bonding, gluing, or thermal or ultrasonic welding. The topsheet and / or liquid barrier layer can be further attached to the core cover by any method known in the art (e.g., adhesive, thermal bonding, welding, etc.).

[0111] The pant-type article may have a two-part chassis with a crotch panel connected to the front panel along the front panel's crotch edge and connected to the back panel along the back panel's crotch edge. The front and back panels may be made of elastic or stretchable web material or elastic laminate material, and the crotch panel may be an inelastic web material or an inelastic laminate material. Alternatively, the pant-type article may have a unitary chassis with an inelastic outer or inner cover web extending the entire distance between the front and back waist edges, the cover web constituting the inelastic layer of each of the front and back portions and constituting the crotch web material in the crotch portion of the pant-type article.

[0112] A pant-type article 201 as disclosed herein can have an elastic waist feature 290 disposed along the waist opening 216. The elastic waist feature 290 can be formed by one or more elastic elements extending parallel to the front waist edge 207 and the back waist edge 210. The one or more elastic waist elements can be incorporated into the front portion 203 and the back portion 204 of the article 201, or can be applied as a separate waistband attached to the front waist edge 207 and the back waist edge 210. The pant-type article 201 shown in the figures has an elastic waist feature 290 extending around the entire perimeter of the waist opening 216. However, the elastic waist feature can be disposed only along a portion of the waist opening (e.g., only along the back waist edge, only along the front waist edge, or along a portion of one or both of the front and back waist edges (wherein the portion has a length less than the entire length of the corresponding waist edge)).

[0113] The elastic material in the elastic elements disposed along the leg openings 217, 218 and waist opening 216 as disclosed herein can be any suitable elastic material, such as, for example, natural or synthetic rubber, thermoplastic elastomers (e.g., thermoplastic polyurethanes or styrene block copolymers or elastane (also known as spandex (polyurethane-polyurea copolymer))), etc. The elastic elements can be of the elastane type available under the trade name "LYCRA," although any suitable elastic yarn can be used.

[0114] The upper and lower core cover layers can be constructed of nonwoven materials as disclosed herein.

[0115] The nonwoven web material used in the absorbent article as disclosed herein can include a thermoplastic material. The nonwoven web material will typically be incorporated into the bonded joints and seams in the absorbent article, and it may be desirable for the nonwoven web to be weldable by heat or ultrasonic welding process. Examples of polymers suitable for use in the fibrous nonwoven web as disclosed herein include polyethylene, polypropylene, and other polyolefin homopolymers and copolymers, and polyester. Weldable nonwoven webs have a high content of thermoplastic components, preferably containing at least 50% thermoplastic fibers, more preferably at least 80% thermoplastic fibers. [Explanation of symbols]

[0116] 101 Mat forming machine 102 Rotary mat forming drum 104 First core cover web 104' pleated primary core cover web 105 First Surface 106 Second Surface 108 Pleat forming unit 109 pleats 110 First adhesive applicator 111 side edge 112 Matte forming surface 113 Recess 114 Bottom surface 115 Channel-forming elements 120 Air Laying Unit 121 Wood pulp, absorbent materials, cellulose pulp fibres 122 Superabsorbent Materials 124 Second Core Cover Web 125 First Surface 126 Second Surface 130 Secondary Adhesive Applicator 131 Spinning Wheel 140 Absorbent Laminate 141 Cutting Unit 142 absorbent core 201 Pants-type items 203 Front part 204 Rear part 206 Crotch area 207 Front waist edge 208 first front side edge 209 Second front side edge 210 rear waist edge 211 first rear side edge 212 second rear side edge 214 First side seam 215 Second side seam 216 Waist opening 217 First leg opening 218 Second leg opening 219' First leg edge 219" Second leg edge 220 Absorbable Assembly 221 Absorbent Core 222 top sheet 223 Liquid Barrier Layer 224 Upper core cover layer 225 Lower Core Cover Layer 226 first side edge 227 Second side edge 228 first end edge 229 Second end edge 233 First Side Seal 234 Second Side Seal 235 First Channel 236 Second Channel 237 First Channel Seal 238 Second Channel Seal 251 Central part, first core part 252 Front end part, second core part 253 Rear end part, third core part 254 Anterior Transition Zone 255 Rear Transition Zone 290 Elastic waist feature CD Cross Machine Direction L Longitudinal direction Lc Longitudinal center line MD Machine Direction T transverse direction V vacuum force w1 first width, first lower core cover width w2 Second width, second core cover width

Claims

1. A method for manufacturing an absorbent core (142, 221) for a disposable absorbent hygienic article (201), said method comprising: - providing a first core cover web (104) having a first surface (105) and a second surface (106); advancing the first core cover web (104) in a machine direction (MD), the first core cover web (104) having side edges (111) extending in the machine direction (MD), a first lower core cover width (w1) being defined in a cross-machine direction (CD) between the side edges (111) of the first core cover web (104), the cross-machine direction (CD) being perpendicular to the machine direction (MD); - introducing at least one pleat (109) into the first core cover web (104), the at least one pleat (109) extending in the machine direction (MD) between the side edges (111) of the first core cover web (104) to form a pleated first core cover web (104'), the pleated first core cover web (104') having a second core cover width (w2) between the side edges (111) of the pleated first core cover web (104'), the second core cover width (w2) being smaller than the first lower core cover width (w1); - applying adhesive to the first surface (105) of the pleated first core cover web (104'); - advancing the pleated first core cover web (104') onto a mat-forming surface (112) of a mat-former (101), the mat-former having a recess (113) disposed on the mat-forming surface (112), the recess (113) having an air-permeable bottom surface (114) and including at least one channel-forming element (115) disposed on and protruding from the bottom surface (114) of the recess (113); - fitting the pleated first core cover web (104') into the recess (113) and the at least one channel-forming element (115) on the bottom surface (114) of the recess (113), with the second surface (106) of the first core cover web (104) facing the bottom surface (114) of the recess (113), causing the pleats (109) in the first core cover web (104) to at least partially unfold in the at least one channel-forming element (115); - applying an absorbent material (121, 122) onto the first surface (105) of the first core cover web (104) in the recess (113); - providing a second core cover web (124) having a first surface (125) and a second surface (126); - applying an adhesive onto said first surface (125) of said second core cover web (124); - applying said second core cover web (124) to said first core cover web (104) and to said absorbent material (121, 122) disposed on said first core cover web (104); - forming an absorbent laminate (140) comprising said absorbent material (121, 122), said second core cover web (124), and said first core cover web (104) by pressing said second core cover web (124) and said first core cover web (104) together; - forming individual absorbent cores (142) by cutting the absorbent laminate (140) in the cross machine direction (CD); A method comprising:

2. 10. The method of claim 1, wherein two or more pleats (109) are introduced into the first core cover web (104).

3. 3. The method according to claim 1 or 2, wherein the second core cover width (w2) is 65% to 97% of the first lower core cover width (w1).

4. 4. The method according to claim 1, wherein the mat-forming machine comprises a rotatable mat-forming drum (102), the mat-forming surface is a peripheral surface (112) of the rotatable mat-forming drum (102), and the recesses (113) are arranged in the peripheral surface (112) of the rotatable mat-forming drum (102).

5. 5. The method of claim 4, wherein the recesses (113) in the peripheral surface (112) of the rotatable mat-forming drum (102) are continuous recesses (113) extending around the periphery of the rotatable mat-forming drum (102).

6. 6. The method of claim 5, wherein each of the at least one channel-forming element (115) is comprised of 2 to 15 element parts, the element parts being equidistantly distributed around the periphery of the rotatable mat-forming drum (102), and the absorbent laminate (140) is cut in the cross-machine direction (CD) between the element parts in the step of forming individual absorbent cores (142).

7. 5. The method of claim 4, wherein the recess (113) in the peripheral surface (112) of the rotatable mat-forming drum (102) is one of a plurality of recesses (113) in the peripheral surface of the rotatable mat-forming drum (102).

8. 8. The method according to claim 1, wherein two or more channel-forming elements (115) are arranged side by side on the bottom surface of the recess (113) in the mat-forming surface (112), each of the two or more channel-forming elements (115) extending in the machine direction (MD).

9. 9. The method of any one of claims 1 to 8, wherein the absorbent material comprises cellulose pulp fibers (121) and superabsorbent material (122).

10. 10. The method of claim 9, wherein the cellulose pulp fibers (121) and the superabsorbent material (122) are applied as a mixture onto the first surface (105) of the first core cover web within the recesses (113) in the mat-forming surface (112).

11. 11. The method of claim 10, wherein the mixture of cellulose pulp fibers and superabsorbent material (121, 122) is a homogeneous mixture, and the superabsorbent material (122) constitutes 5% to 80% by weight of the mixture (121, 122).

12. 12. The method according to any one of claims 1 to 11, wherein the adhesive is distributed evenly on the first surface (105) of the pleated first core cover web (104').

13. 12. The method of claim 1, wherein the adhesive is selectively distributed onto the first surface (105) of the first core cover web (104, 104'), and no adhesive is applied to areas of the first core cover web (104, 104') corresponding to the location of the at least one channel forming element (115).

14. 14. The method according to any one of claims 1 to 13, wherein the adhesive is distributed evenly on the first surface (125) of the second core cover web (124).

15. 14. The method of claim 1, wherein the adhesive is selectively distributed onto the first surface (125) of the second core cover web (124) and / or a higher concentration of adhesive is applied to the first surface (125) of the second core cover web (124) in areas corresponding to the location of the at least one channel-forming element (115).

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