WO2022268304A1

WO2022268304A1 - An absorbent core for a wearable absorbent article and a wearable absorbent article including said absorbent core

Info

Publication number: WO2022268304A1
Application number: PCT/EP2021/067022
Authority: WO
Inventors: Haiying GUO; Huimin Wu
Original assignee: Essity Hygiene And Health Aktiebolag
Priority date: 2021-06-22
Filing date: 2021-06-22
Publication date: 2022-12-29
Also published as: CN117295476A

Abstract

The present invention relates to an absorbent core for a wearable absorbent article. The absorbent article including: an elongated central portion 2 having a front region C, a rear region D and a crotch region A arranged between the front region C and the rear region D in a longitudinal direction of the absorbent core 1, two outer peripheral portions B, B' located adjacent to opposite sides of the central portion 2 in a transverse direction perpendicular to the longitudinal direction of the absorbent core 1 at least in the crotch region A, wherein the crotch region A and the two outer peripheral portions B, B' are unitarily formed, the two outer peripheral portions B, B' have a first average thickness and/or density, the crotch region A of the elongated central portion 2 has a second average thickness and/or density that is greater than the first average thickness and/or density. The present invention further relates to a wearable, preferably disposable, absorbent article 100 including the absorbent core 1 of the present invention.

Description

AN ABSORBENT CORE FOR A WEARABLE ABSORBENT ARTICLE AND A WEARABLE ABSORBENT ARTICLE INCLUDING SAID

ABSORBENT CORE

TECHNICAL FIELD

The present invention relates to an absorbent core for a wearable absorbent article. The present invention also relates to a wearable absorbent article including said absorbent core.

BACKGROUND ART

Besides good absorptive properties, primary requirements of absorbent articles, in particular wearable absorbent articles, are good fit and comfort. In particular with regard to female products, customers are more concerned about whether the product has leakage problem during and after use, whether it is comfortable during use, and whether the product fits well. Various methods have been employed in the design and manufacture of wearable absorbent articles so that they follow the contours of the user’s body well and do not move out of placing during use.

EP 1101477 discloses a body fluid absorbent garment including a liquid- absorbent core formed with a pair of protruding barriers adapted to barrier off liquid extraction. The core comprises a mixture of fluff and high molecular water-absorbent polymer particles compressed to a desired thickness. The protruding barriers are disclosed to have a density lower than that of the core in a base zone thereof free from formation of the protruding barriers. EP 1 275 358 describes an absorbent article having a front absorbent region and a rear cushion region. The stiffness is higher in the front absorbent region, such that the shape of the raised region is maintained. Conventionally, the cores of wearable absorbent articles basically have rectangular, trapezoidal and dumbbell shape. In case of a rectangular core, the center part is wide enough to effectively prevent lateral leakage, but this shape is not conducive to core fits the body contour. On the other hand, trapezoidal and dumbbell-shaped cores, which improve the core fitting problem and thus the wearing comfort, are narrower in the center, which easily leads to leakage problems.

Hence, in order to solve the above problems, conventional absorbent cores are often thicker as needed, which leads to a stiffer core and a reduced wearing comfort. Moreover, if the thickness of the core is increased, breathability is reduced. On the other hand, in case the thickness of the core is too thin, even though the core fitting problem can be solved, but the absorption becomes insufficient, leading to an increased risk of leakage.

Hence, there is still room for improvement in the comfort and fit of wearable absorbent articles such as sanitary napkins, diapers, in particular pull-on diapers or pants-type diapers, incontinence garments and feminine garments.

SUMMARY

In view of the above, it would be desirable to provide an absorbent core for a wearable absorbent article capable of increasing the absorption capacity, thus, reducing the risk of leakage, in particular lateral leakage, while increasing comfort of a user. This may be achieved by an absorbent core for a wearable absorbent article according to claim 1 and a wearable absorbent article according to claim 16. Embodiments may be found in the dependent claims, the following description and the accompanying drawings.

The present invention provides an absorbent core for a wearable absorbent article, having an elongated central portion provided with two outer peripheral portions located adjacent to opposite sides of the central portion in a transverse direction perpendicular to the longitudinal direction of the absorbent core at least in a crotch region of the central portion, wherein the two outer peripheral portions have a first average thickness and/or density, the crotch region has a second average thickness and/or density that is greater than the first average thickness and/or density.

This makes it possible to provide an absorbent core capable of increasing the absorption capacity of a wearable absorbent article, thus reducing the risk of leakage of the absorbed liquid, especially lateral leakage. In addition, it is possible to reduce the stiffness of the absorbent core, in particular in the center region thereof, thereby increasing bendability and comfort during use. Yet, as the thickness of the absorbent core can be at least partially reduced, breathability can be improved, hence, avoiding skin discomfort after prolonged use.

According to one embodiment of the present invention, an absorbent core for a wearable absorbent article is provided. The absorbent core includes: an elongated central portion having a front region, a rear region and a crotch region arranged between the front region and the rear region in a longitudinal direction of the absorbent core, two outer peripheral portions located adjacent to opposite sides of the central portion in a transverse direction perpendicular to the longitudinal direction of the absorbent core at least in the crotch region, wherein at least the crotch region of the central portion and the two outer peripheral portions are unitarily formed, the two outer peripheral portions have a first average thickness and/or density, the crotch region of the elongated central portion has a second average thickness and/or density that is greater than the first average thickness and/or density.

In the context of the present invention the term “unitary” with regard to the crotch region and the two outer peripheral portions is to be understood such that the crotch region and the two outer peripheral portions are constructed from essentially one type of material, this being essentially the same material, or essentially the same combination of two or more materials throughout the crotch region and the two outer peripheral portions. Variations in density and concentration of the material may occur, but these are limited to those which can be obtained without incorporation of regions which have been formed separately and then physically joined to each other. For example, when the crotch region and the two outer peripheral portions comprise a matrix of hydrophilic fibres and superabsorbent material as described in more detail below, the relative concentrations of superabsorbent material and fibres may be different in different parts of the crotch region and the two outer peripheral portions. However, the crotch region and the two outer peripheral portions should not, for instance, comprise layers or laminates of different composition. Likewise, variations in the density or concentration of various components across the longitudinal or transverse directions of the crotch region and the two outer peripheral portions are acceptable yet the crotch region and the two outer peripheral portions should not comprise areas or layers of different composition which are formed separately and later joined together.

A suitable technique for forming the absorbent core, in particular the crotch region and the two outer peripheral portions, of the present invention is mat forming thorough an air-laying process, as illustrated in Figures 5a to 5c and as described more closely in EP-A2-1 253 231. An air-permeable mould 52 having the desired shape is provided. The depth of the mould can vary, as seen in the cross-sectional view in Figure 5a, according to the amount of material which is required at each point. Fibrous material 54 is air-laid into the mould, and the mould is filled (see Fig. 5b). Due to the difference in the mould depth in various areas, the amount of fibrous material at each point will vary (Fig. 5c).

Moreover, in the context of the present invention the term “at least in the crotch region” with regard to the two outer peripheral portions should be understood to mean that the two outer peripheral portions may extend not only along the two opposite sides of the central portion, but also at least partially along the front region and/or the back region of the central portion. According to a further embodiment of the present invention, in an area of the absorbent core in which the two outer peripheral portions are located, a first width, in particular a maximal width, of the absorbent core in the transverse direction of the absorbent core is larger than a second width, in particular a minimal width, in adjacent areas of the absorbent core in the longitudinal direction of the absorbent core.

In the context of the present invention, the term “adjacent area(s)” with regard to the absorbent core is to be understood as a region(s) closest to the two outer peripheral portions.

Moreover, in one embodiment, the adjacent area located between the crotch region and the front region might have a different minimal width, in particular a smaller minimal width, than the adjacent area located between the crotch region and the rear region.

According to a further embodiment of the present invention, concave contour lines are formed where the two outer peripheral portions border the central portion, in particular at the adjacent areas of the absorbent core.

In some embodiments, embossed folding lines are formed in the area where the two outer peripheral portions border the elongated central portion, in particular the crotch region.

Additionally, in some embodiments of the present invention, the absorbent core has a trapezoidal shape, where the front region is preferably formed narrower than the rear region. In a preferred embodiment of the present invention, the front region is arranged in front of the crotch region and the rear region is arranged behind the crotch region as viewed in a front-rear-direction of the absorbent core when embedded in a or the wearable absorbent article or as viewed in the longitudinal direction of the absorbent core when embedded in the wearable absorbent article.

Moreover, in some embodiments of the present invention, the crotch region and the two outer peripheral portions have together a first width in the transverse direction perpendicular to the longitudinal direction of the absorbent core that is wider than a third width of the front region but narrower than a fourth width of the rear region.

In some embodiments, the front region has a third width in the range of 80 mm to 110 mm. Moreover, in a preferred embodiment the rear region has a fourth width in the range of 130 mm to 150 mm.

According to a further embodiment, the width of the front most part of the rear region is wider than the width of the rear most part of the rear region.

In one embodiment, the front region and/or the rear region has/have a lower thickness and/or density than the crotch region, the thickness and/or density of the two outer peripheral portions being preferably lower than the thickness and/or density of the front region and/or the rear region.

According to a further embodiment, the crotch region may have a thickness in the range of 4 mm to 8 mm. The thickness is measured on a complete product (e.g. wearable absorbent article) including the absorbent core and the cover sheets. The complete product, in particular the wearable absorbent article, is described in more detail below. In order to avoid wrinkles in the sample during measurement, the leg elastics (also described in more detail below) are removed.

In some embodiments, the crotch region may have a grammage weight in the range of 240 gsm to 340 gsm and the two outer peripheral portions may preferably have a grammage weight in the range of 95 to 195 gsm. Moreover, in some embodiments the weight ration of SAP to pulp for both the crotch region and the two outer peripheral portions may be in the range of 0 to 0.5.

In the following, the respective measurement procedure is described in more detail. In a first step, samples are cut or punched from the area of interest. Then the thickness of the sample is measured under a pressure of 0.5 kPa. Hereby, the thickness gauge foot should rest over the sample for about 5 seconds before the thickness value is read. The are of the sample can be determined with a ruler. Yet, if the contours of the sample are irregular, the sample may be photocopied or scanned, and the area of interest can then be determined using a planimeter or suitable image analysis software. The absorbent core sample is then weighted to the nearest milligram (the including materials are carefully removed to just leave the unitary absorbent core to be measured).

Furthermore, the two outer peripheral portions may have a convex shape facing away from the elongated central portion.

Additionally, the absorbent core may further include a longitudinal channel which is positioned along a longitudinal center line of the core and may be arranged at least in the area of the two outer peripheral portions.

In some embodiments, the longitudinal channel has a starting point in a range of 5 mm to 10 mm before or after the starting points of the two outer peripheral portions, when seen in the longitudinal direction of the core, and an ending point in a range of 5 mm to 10 mm before or after the ending points of the two outer peripheral portions, when seen in the longitudinal direction of the absorbent core.

In the context of the present invention, the starting and ending points of the at least two outer peripheral portions are points located at the transition point between the front and rear areas respectively and the central area on the outer contour of the core.

Furthermore, in some embodiments of the present invention, the longitudinal channel is formed by embossing. Alternatively, the longitudinal channel is formed by mould, and contains less absorbent material than its periphery, or even is free of any absorbent material.

In some embodiments, the absorbent core further includes a cutout provided in the rear region, dividing the rear end of the rear region into two section, wherein the two sections are preferably symmetrically in the transverse direction. By providing the absorbent core with the cutout in the rear region, the absorbent core is given a gingerman-like shape. The cutout may have a depth in the range of 10 mm to 40 mm, preferably 20 mm to 30 mm.

In a preferred embodiment of the present invention, in the area of the absorbent core in which the two outer peripheral portions are located, a smallest width of the absorbent core is in the range of 70 mm to 100 mm and/or a largest width of the absorbent core is in the range of 90 mm to 130 mm.

Moreover, the crotch region and/or the two outer peripheral portions and/or the front and rear regions and/or the longitudinal channel may be formed, in particular integrally, by one single layer and/or made in a mould.

In some embodiments, each of the two outer peripheral portions comprises a cutout dividing the two outer portions into two sections, thereby preferably forming a product folding line. The two sections may be symmetrical in the longitudinal direction of the absorbent core. Accordingly, the cuts dividing the two outer peripheral portions may extend approximately in the transverse direction perpendicular to the longitudinal direction of the absorbent core. Moreover, the cutouts may have a depth in the range of 2 to 10 mm. Moreover, in some embodiments the outer contour of the front region and/or the rear region tapers inwardly, in particular in an arched manner, from an end face of the absorbent core towards the crotch region.

Another embodiment of the present invention provides a wearable, preferably disposable, absorbent article, including the above absorbent core according to any one of the described embodiments.

In some embodiments, the absorbent article is a diaper, in particular a pull-on diaper or a pants-type diaper, an incontinence garment or a feminine garment.

Moreover, in some embodiments, the wearable absorbent article further includes: a front panel; a back panel; and a crotch panel at least partly arranged between the front panel and the back panel; wherein the crotch panel includes: a topsheet; and a backsheet; wherein the absorbent core is provided between the topsheet and the backsheet.

According to a further embodiment of the present invention, the crotch panel is arranged to bridge and at least partially overlap the front panel and the back panel.

Moreover, in some embodiments, the front region and rear region of the absorbent core are arranged in correspondence with a front and back of the wearable absorbent article when worn by a user. Furthermore, the wearable absorbent article may further include an acquisition layer provided between the topsheet and the absorbent core.

In some embodiments, the wearable absorbent article further includes two groups of elastic strips or elongate elastic elements that are arranged preferably symmetrically on both sides of the longitudinal center line of the absorbent core, wherein one end of each of the elastic strips may be arranged on one of the two outer peripheral portions.

According to a further embodiment of the present invention, the other end of each of the elastic strips is arranged further outward in the transfers direction of the absorbent core, width direction of the wearable absorbent article, than the one end and is arranged preferably on the crotch panel, in particular the backsheet.

The wearable absorbent article is using the absorbent core for providing the wearable absorbent article with an absorbent core. Therefore, the further features disclosed in connection with the above description of the absorbent core may also be applied to the wearable absorbent article and vice versa.

All of the above are fully within the scope of the present invention, and are considered to form the basis for alternative embodiments in which one or more combinations of the above-described features are applied, without limitation to the specific combinations disclosed above.

In light of this, there will be many alternatives which implement the teaching of the present invention. It is expected that one skilled in the art will be able to modify and adapt the above disclosure to suite its own circumstances and requirements within the scope of the present invention, while retaining some or all technical effects of the same, either disclosed or derivable from the above, in light of his common general knowledge in this art. All such equivalents, modifications or adaptations fall within the scope of the invention hereby defined and claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete appreciation of the present invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, in which:

Fig. 1 shows a schematic top view of an absorbent core for a wearable absorbent article according to a first embodiment of the present invention; Fig. 2 shows a schematic top view of an absorbent core for a wearable absorbent article according to a second embodiment of the present invention;

Fig. 3 shows a schematic top view of an absorbent core for a wearable absorbent article according to a third embodiment of the present invention;

Fig. 4 shows a schematic top view of a wearable absorbent article according to a fourth embodiment of the present invention; and

Fig. 5 shows cross-sectional views of a method by which the absorbent core of the present invention may be produced.

Embodiments of the present disclosure will now be explained with reference to the drawings. It will be apparent to those skilled in the field of wearable absorbent articles from this disclosure that the following description of the embodiments is provided for illustration only and not for the purpose of limiting the disclosure as defined by the appended claims. Features of the embodiments described below can also be used to further characterize the devices defined in the claims.

Modifications of features can be combined to form further embodiments. Features described in individual embodiments can be provided in a single embodiment if they are not incompatible. Likewise, features described in a single embodiment can be provided in several embodiments individually or in any suitable sub-combination. As used in the specification and the appended claims, the singular forms “a”, “an”, “the” and the like include plural referents unless the context clearly dictates otherwise.

The same reference numerals listed in different figures refer to identical, corresponding or functionally similar elements.

As described hereinafter, for example implementations of the present disclosure relate to an absorbent core for a wearable absorbent article.

Figure 1 shows a schematic top view of an absorbent core 1 for a wearable absorbent article 100 according to a first embodiment of the present invention. As can be taken from Figure 1 , the shown absorbent core 1 includes an elongated central portion 2. The elongated central portion 2 includes a front region C, a rear region D and a crotch region A arranged between the front region C and the rear region D in a longitudinal direction of the absorbent core 1. In the embodiment shown in Figure 1 , the central portion 2 including the regions A, B and C has an approximate trapezoidal shape, where the front region is formed narrower than the rear region D. In other words, a width (third width) W3 in a transverse direction perpendicular to the longitudinal direction of the absorbent core 1 , in particular of the elongated central portion 2, of the front region C is smaller than a width (fourth width) W4 (in the transverse direction perpendicular to the longitudinal direction of the absorbent core 1 ) of the rear region D. Additionally, in the embodiment shown in Figure 1 , the outer contours of the front region C and of the rear region D taper inwardly, in particular in an arched manner, from an end face of the absorbent core 1 towards the crotch region A.

Moreover, in the shown embodiment the central portion 2 has four rounded edges. As can also be taken from Figure 1 , the absorbent core 1 includes two outer peripheral portions B, B’ that are located adjacent to opposite sides of the central portion 2 in the transverse direction perpendicular to the longitudinal direction of the absorbent core.

In the shown embodiment, the two outer peripheral portions B, B’ have a starting point in the area where the front region C borders the crotch region A and an ending point that lies before the area where the crotch region A borders the rear region D. However, it is also possible that the two outer peripheral portions B, B’ have a starting point which lies (seen from the front of the absorbent core 1 ) behind the area where the front region C borders the crotch region A and/or an ending point that lies on or after the area where the crotch region A borders the rear region D.

The crotch region A and the two outer peripheral portions B, B’ are unitarily formed such that the two outer peripheral portions B, B’ have a first average thickness and/or density and the crotch region A of the elongated central portion 2 has a second average thickness and/or density, wherein the second average thickness and/or density is greater than the first average thickness and/or density.

Figure 1 also shows that concave contour lines are formed where the two outer peripheral portions B, B’ border the central portion 2. Moreover, in the shown embodiment, in an area of the absorbent core in which the two outer peripheral portions B, B’ are located, a first width Wi (width of the central portion 2 + width of the two outer peripheral portions B, B’ in the transverse direction of the absorbent core 2) of the absorbent core 1 is larger than a second width W2 in adjacent areas E, E’ of the absorbent core in the longitudinal direction of the absorbent core 1 . As can also be taken from Figure 1 , the two outer peripheral portions B, B’ have a convex shape facing away from the elongated central portion 2.

Figure 1 also shows that the crotch region A and the two outer peripheral portions B, B’ have together a width, namely the first width W-i, that is wider than a third width W3 of the front region C but narrower than a fourth width W4 of the rear region D. As can also be taken from Figure 1 , the width of the front most part of the rear region D, namely where the crotch region A borders the rear region D, is wider than the width of the rear most part of the rear region D.

Figure 2 shows a schematic top view of an absorbent core 1 for a wearable absorbent article 100 according to a second embodiment of the present invention. The absorbent core 1 according to the second embodiment corresponds in general to the absorbent core 1 of the first embodiment, wherein it additionally includes a longitudinal channel 3 that is positioned along a longitudinal center line CL of the core 1 and extending from the border between the front region C and the crotch region A until the border between the crotch region A and the rear region D. However, the longitudinal channel 3 might also be longer or shorter than shown in Figure 2.

Moreover, as can also be taken from Figure 2, the absorbent core 1 might include a cutout 4 provided in the rear portion D for dividing the rear end of the rear portion D into two sections. Figure 2 also shows that the cutout 4 is arranged symmetrically to the longitudinal center line CL, thereby, dividing the rear end of the rear portion D into two symmetrical sections with regard to the longitudinal center line CL. By providing the absorbent core 1 with the cutout 4, the absorbent core 1 is given a gingerman-like shape.

Figure 3 shows a schematic top view of an absorbent core 1 for a wearable absorbent article 100 according to a third embodiment of the present invention. The absorbent core 1 according to the third embodiment corresponds in general to the absorbent core 1 of the first embodiment, wherein each of the two outer peripheral portions B, B’ is provided with a cutout 5 dividing the two outer portions B, B’ into two sections Bi, B2; B3, B4, thereby forming a product folding line that extends approximately perpendicular to the longitudinal direction of the absorbent core 1. The four sections Bi, B2; B3, B4 are symmetrically with regard to the folding line and with regard to the longitudinal center line CL.

Furthermore, even though in the above, the four sections Bi, B2; B3, B4 are arranged symmetrically, other configurations are contemplated. For example, the two front sections Bi, B3 may have a greater length in the longitudinal direction of the absorbent core than the two rear sections B2, B4. Thereby, making it possible to arrange the generated folding line on the desired position in the longitudinal direction of the absorbent core 1 .

Figure 4 shows a schematic top view of a wearable absorbent article 100 according to a fourth embodiment of the present invention. As can be seen in Figure 4, the wearable absorbent article 100 includes a front panel 101 , a back panel 102 and a crotch panel 103 that is partly arranged between the front panel 101 and the back panel 102. The shown crotch panel 103 includes a topsheet and a backsheet, wherein the absorbent core 1 of the present invention is provided between the topsheet and the backsheet. Figure 4 also shows that the crotch panel 103 is arranged to bridge and partially overlap the front panel 101 and the back panel 102. Moreover, Figure 4 shows that the front region C and the rear region D of the absorbent core 1 are arranged in correspondence with a front and back of the wearable absorbent article 100, in particular when worn by a user. In use, the front panel 101 of the wearable absorbent article 100 is intended to cover the pubic region of the wearer.

Figure 4 also shows that the wearable absorbent article 100 according to the fourth embodiment includes an acquisition layer 105 provided between the topsheet and the absorbent core. The shown absorbent article 100 also includes two groups of elastic strips 104, each group consisting of three stripes, that are arranged symmetrically on both sides of the longitudinal center line of the absorbent core, wherein the front end of the elastic strips 104 is arranged on one of the two outer peripheral portions, in particular while not crossing the longitudinal center line of the absorbent core 1 . The other end (rear end) of each of the groups of elastic strips 104 is arranged further outward in the transfers direction of the absorbent core 1 (width direction of the wearable absorbent article 100) than the front end and is arranged on the crotch panel 103, in particular the backsheet.

Moreover, the topsheet lies in direct contact with the wearer’s body, and should therefore be soft, comfortable and liquid-permeable. The inner coversheet can comprise a nonwoven material, e.g. spunbond, meltblown, carded, hydroentang led, wetlaid etc. Suitable nonwoven materials can be composed of natural fibres, such as wood pulp or cotton fibres, manmade fibres, such as polyester, polyethylene, polypropylene, viscose etc. or from a mixture of natural and manmade fibres. The topsheet material may further be composed of tow fibres, which may be bonded to each other in a bonding pattern, as e.g. disclosed in EP 1 035 818 A. Further examples of topsheet materials are porous foams, apertured plastic films etc. The materials suited as topsheet materials should be soft and non-irritating to the skin and be readily penetrated by body fluid, e.g. urine or menstrual fluid. The topsheet may further be different in different parts of the absorbent article.

The backsheet lies in contact with the wearer's garments, and is liquid- impermeable. The backsheet refers to the liquid im pervious material forming the outer cover of the absorbent article. The backsheet can comprise a thin plastic film, e.g. a polyethylene or polypropylene film, a nonwoven material coated with a liquid impervious material, a hydrophobic nonwoven material, which resists liquid penetration, or a laminate of a plastic film and a nonwoven material. Other laminate materials which are suitable for use as the backsheet are laminates of a nonwoven material and high-loft wadding material. The backsheet material may be breathable so as to allow vapour to escape from the absorbent core, while still preventing liquids from passing therethrough. Examples of breathable backsheet materials are porous polymeric films, nonwoven laminates of spunbond and meltblown layers and laminates of porous polymeric films and nonwoven materials. Preferably, the backsheet comprises nonwoven material in at least the garment-facing surface thereof.

Furthermore, the acquisition (distribution) layer 105 which is placed on top of the absorbent core 1 and adapted to quickly receive and temporarily store discharged liquid before it is absorbed by the absorbent core 1 , is well known in the art and may be composed of porous fibrous wadding, SD plastic film, LDA (low density airlaid), multiband, latex bonded or foam materials.

Figures 5a to 5c illustrate a suitable technique for forming the absorbent core of the present invention, namely mat-forming through an air-laying process, as is described more closely in EP-A2-1 253 231 . An air-permeable mould 52 having the desired shape is provided. The depth of the mould can vary, as seen in the cross-sectional view in Figure 5a, according to the amount of material which is required at each point. Fibrous material 54 is air-laid into the mould, and the mould is filled (see Fig. 5b). Due to the differences in the mould depth in various areas, the amount of fibrous material at each point will vary (Fig. 5c).

After the absorbent core is produced, the core is then compressed with a profiled roll, such that different thicknesses are obtained over the extent of the absorbent core (i.e. in the longitudinal and transverse direction). Figure 5d shows the cross section of an absorbent core 1 according to the present invention, where the crotch region A of the elongated central portion 2 is compressed more than the two outer peripheral portions B, B’, which also have a lower final thickness as the crotch region A. Accordingly, in the embodiment shown in Fig. 5d the thickness and density of the two outer peripheral portions B, B’ is lower than the thickness and density of the crotch region.

In this way, areas of different densities can be built up within the absorbent core 1. If desired, masks or baffles may be introduced in the mat-form ing process, so that fibre-laying in the unmasked areas is higher than in the masked areas. Alternatively, the moulds may have different hole density and/or hole size in different areas of the mould. The flow of fibrous material will therefore be different in different areas of the mould. This allows further control over the material density.

Claims

1. An absorbent core (1 ) for a wearable absorbent article (100), the absorbent core (1) comprising: an elongated central portion (2) having a front region (C), a rear region (D) and a crotch region (A) arranged between the front region (C) and the rear region (D) in a longitudinal direction of the absorbent core (1), two outer peripheral portions (B, B’) located adjacent to opposite sides of the central portion (2) in a transverse direction perpendicular to the longitudinal direction of the absorbent core (1) at least in the crotch region (A), wherein the crotch region (A) and the two outer peripheral portions (B, B’) are unitarily formed, the two outer peripheral portions (B, B’) have a first average thickness and/or density, the crotch region (A) of the elongated central portion (2) has a second average thickness and/or density that is greater than the first average thickness and/or density.

2. The absorbent core (1 ) according to claim 1 , wherein, in an area of the absorbent core (1) in which the two outer peripheral portions (B, B’) are located, a first width (Wi) of the absorbent core (1 ) in the transverse direction of the absorbent core (1 ) is larger than a second width (W2) in adjacent areas (E, E’) of the absorbent core in the longitudinal direction of the absorbent core (1).

3. The absorbent core (1 ) according to claim 1 or 2, wherein concave contour lines are formed where the two outer peripheral portions (B, B’) border the central portion (2), in particular at the adjacent areas (E, E’) of the absorbent core (1).

4. The absorbent core (1 ) according to any one of the preceding claims, wherein the absorbent core (1) has a trapezoidal shape, where the front region (C) is preferably formed narrower than the rear region (D).

5. The absorbent core (1 ) according to any one of the preceding claims, wherein the crotch region (A) and the two outer peripheral portions (B, B’) have together a first width (Wi) that is wider than a third width (W3) of the front region (C) but narrower than a fourth width (W4) of the rear region (D).

6. The absorbent core (1 ) according to any one of the preceding claims, wherein the front region (C) has a third width (W3) in the range of 80 mm to 110 mm and the rear region (D) has preferably a fourth width (W4)in the range of 130 mm to 150 mm.

7. The absorbent core (1 ) according to any one of the preceding claims, wherein the width of the front most part of the rear region (D) is wider than the width of the rear most part of the rear region (D).

8. The absorbent core (1 ) according to any one of the preceding claims, wherein the front region (C) and/or the rear region (D) has/have a lower thickness and/or density than the crotch region (A), the thickness and/or density of the two outer peripheral portions (B, B’) being preferably lower than the thickness and/or density of the front region (C) and/or the rear region (D).

9. The absorbent core (1 ) according to any one of the preceding claims, wherein the two outer peripheral portions (B, B’) have a convex shape facing away from the elongated central portion (2).

10. The absorbent core (1 ) according to any one of the preceding claims, further comprising a longitudinal channel (3) which is positioned along a longitudinal center line (CL) of the core (1 ) and arranged at least in the area of the two outer peripheral portions (B, B’).

11 . The absorbent core (1 ) according to claim 10, wherein the longitudinal channel (3) has a starting point in a range of 5 mm to 10 mm before or after the starting points of the two outer peripheral portions (B, B’) and an ending point in a range of 5 mm to 10 mm before or after the ending points of the two outer peripheral portions (B, B’).

12. The absorbent core (1 ) according to claim 10 or 11 , wherein the longitudinal channel (3) is formed by embossing or the longitudinal channel (3) is free of any absorbent material.

13. The absorbent core (1 ) according to any one of the preceding claims, further comprising a cutout (4) provided in the rear region (D), dividing the rear end of the rear region (D) into two, preferably in the transverse direction symmetrical, sections.

14. The absorbent core (1 ) according to any one of the preceding claims, wherein, in the area of the absorbent core (1 ) in which the two outer peripheral portions (B, B’) are located, a smallest width (W2) of the absorbent core (1) is in the range of 70 mm to 100 mm and/or a largest width (Wi) of the absorbent core (1 ) is in the range of 90 mm to 130 mm.

15. The absorbent core (1) according to any one of the preceding claims, wherein each of the two outer peripheral portions (B, B’) comprises a cutout (5) dividing the two outer portions (B, B’) into two, preferably in the longitudinal direction of the absorbent core (1 ) symmetrical, sections (Bi, B2; B3, B4), preferably forming a product folding line.

16. The absorbent core (1 ) according to any one of the preceding claims 3 to 15 and dependent on claim 2, wherein the outer contour of the front region (C) and/or the rear region (D) tapers inwardly, in particular in an arched manner, from an end face of the absorbent core (1 ) towards the crotch region (A).

17. A wearable, preferably disposable, absorbent article (100) comprising: the absorbent core (1 ) according to any one of the preceding claims.

18. The wearable absorbent article (100) according to claim 17, further comprising: a front panel (101); a back panel (102); and a crotch panel (103) at least partly arranged between the front panel (101) and the back panel (102); wherein the crotch panel (103) comprises: a topsheet; and a backsheet; wherein the absorbent core (1) is provided between the topsheet and the backsheet.

19. The wearable absorbent article (100) according to claims 17 or 18, further comprising an acquisition layer (105) provided between the topsheet and the absorbent core (1).

20. The wearable absorbent article (100) according to any one of the preceding claims 16 to 18, further comprising two groups of elastic strips or elongate elastic elements (104) that are arranged preferably symmetrically on both sides of the longitudinal center line of the absorbent core (1 ), wherein one end of each of the elastic strips (104) is arranged on one of the two outer peripheral portions (B, B’).

21. The wearable absorbent article (100) according to claim 19, wherein the other end of each of the elastic strips (104) is arranged further outward in the transfers direction of the absorbent core (1 ) than the one end and is arranged preferably on the crotch panel (103), in particular the backsheet.