WO2026008158A1 - Sustainable absorbent article with fluid flow control structure - Google Patents

Abstract

Provided herein is an absorbent article having a liquid permeable topsheet (1), a liquid impermeable backsheet (4), an absorbent core (3) arranged between the topsheet (1) and the backsheet (4), and a fluid flow control structure (2, 20) arranged between the topsheet (1) and the absorbent core (3). The fluid flow control structure (2, 20) has a first layer (21) that includes an apertured three-dimensional film formed from regenerated cellulose.

Description

Sustainable absorbent article with fluid flow control structure

Field of the invention

[0001] The present disclosure relates to absorbent articles, such as sanitary towels, panty liners, incontinence pads or diapers, which are made with sustainable materials and designed to accommodate a balance between efficient fluid handling and user comfort. In particular, these absorbent articles are configured to provide improved retention of absorbed fluid(s), to minimize the occurrence of surface wetness and/or rewet during use, and to further enhance wearer comfort and confidence in the articles.

Background

[0002] Absorbent articles, such as sanitary napkins, panty liners, diapers, incontinence pads, and the like need to have good absorptive properties and should provide the wearer with a sense of security against leakage. Such absorbent articles are generally constructed with a liquid permeable topsheet, a liquid impermeable backsheet, and an absorbent structure arranged between the topsheet and the backsheet.

[0003] A typical topsheet, which is arranged on the user facing side of the absorbent article, may be formed from nonwoven material(s), apertured films, or combinations (e.g., non-woven/film composite or laminate). In contrast, backsheets, which are arranged on the garment facing side of the absorbent articles, are typically made of films, for example, a solid polymer film. In some cases, these films may even include breathable materials that do not impact the imperviousness of the backsheet to fluid leakage. Further, the absorbent structure(s), i.e. absorbent core, may be made from a variety of materials, including but not limited to pulp, other fibrous materials, superabsorbent particles or fibers, and combinations thereof.

[0004] One or more additional layers may be provided between the topsheet and the absorbent structure to further facilitate liquid handling, mainly intake and distribution, into and within the absorbent article. One example of such an additional layer is EP 2353562 A1 , which describes a composite suitable for use as a transfer layer, or acquisition distribution layer, in an absorbent article between the topsheet and the absorbent core to promote fluid distribution, reduce surface wetness in the topsheet, and reduce or eliminate rewet in general.

[0005] However, a vast majority of the disposable absorbent articles that are currently commercially available contain a significant amount of material(s) sourced from petrochemicals, such as petroleum-based fibers and petroleum-based polymers, usually in both the topsheet and backsheet layers. Not to mention, the absorbent core and/or additional layers typically contain synthetic superabsorbent polymers (SAP) which are also often derived from petroleum-based polymers or materials. These materials are not sustainable and contribute to an ever-growing waste stream of used absorbent articles that ultimately end up in traditional landfills. Thus, there is an existing demand for alternative solutions to remediate the impact of such disposable absorbent articles on available resources and the environment. [0006] In addition, conventional source materials, such as plastics, currently used in the manufacture of commercially available disposable absorbent articles possess certain desirable characteristics, including but not limited to breathability, processability, durability, and absorbent capacity (e.g., fluid retention) that are imparted to the absorbent articles. Sustainable materials must, therefore, provide these same characteristics in orderto be acceptable substitutes; otherwise, consumers may lose confidence in or simply reject products containing the same.

[0007] Consequently, there remains a need to provide absorbent articles formed from sustainable materials that possess efficient fluid handling properties without sacrifice to user comfort. Relatively high retention of absorbed bodily discharge(s), security against leakage, and comfortability, particularly relating to a perceived feeling of dryness during use of the absorbent articles, are exemplary characteristics that are desirable to consumers and should at least be comparable to, if not improved over, those provided by the conventional plastic-based source materials typically found in absorbent articles that are commercially available to date.

Summary

[0008] Now more than ever there is a need to shift from the use of conventional source materials such as plastics in the manufacture of disposable absorbent articles to more sustainably-based and renewable source materials, such as non-plastics. However, absorbent article characteristics, including but not limited to efficient fluid handling and user comfort, that are highly desirable for consumers should not be diminished due to this shift. Rather, alternative solutions using sustainable material(s) should have such properties that are at least comparable, relative to those provided by absorbent articles manufactured using typical plastic-based source materials.

[0009] In addition, it has been found that despite prior art solutions for disposable absorbent articles, there is still a need to improve the fluid handling properties of such articles, especially with respect to fluid intake and retention within the absorbent article. In this regard, it is important that the absorbent articles are enabled to effectively capture and retain absorbed fluid(s) in a desired and predetermined manner, and by extension, prevent leakage therefrom. Not to mention, it is highly desirable that the absorbent articles provide the wearer with a continued sense of dryness during use of the article.

[0010] An objective of the present disclosure is thus to provide an absorbent article having efficient fluid handling properties that is also made using sustainable material(s). Further, it is desirable that the absorbent article be provided with improved performance and comfort. Incontinence shields and sanitary napkins are designed to have a total absorption capacity that is large enough to absorb all fluid that is expected to be released to the absorbent article during a period of wear. However, the fluid is normally not exuded in a steady flow but as sudden gushes of relatively large volume under pressure and during a very short time period. In this regard, the absorbent article should be enabled to manage a rapid rush of fluid discharged by the wearer, such as urine or menstrual blood, quickly and efficiently. More particularly, it is desirable that the absorbed fluid is able to quickly reach the absorbent core where it is efficiently distributed and securely retained. [0011] In terms of fluid handling, it is desirable that the absorbent article is enabled to minimize the occurrence of surface wetness and/or rewet at any point during use. Further, it is desirable that the absorbent article has a relatively high level of retention of absorbed fluid(s) and that the thickness of the individual layers, especially the fluid flow control structure, are substantially maintained even when subjected to compressive forces normally exerted during use.

[0012] It is further desirable still to provide an absorbent article that is both discrete and comfortable to wear. Any one or more of the aforementioned properties may additionally contribute to and/or improve the comfort level of a user when wearing the absorbent article.

[0013] It is also an objective to provide an absorbent article in which leakage security is not reduced, if not all together unaffected.

[0014] Depending on the desired application, the absorbent articles described herein may take the form of any one of a sanitary towel, sanitary napkin, a panty liner, an incontinence pad, an incontinence liner or a diaper.

[0015] In the interest of sustainability, it may be even further desirable to provide an absorbent article that is partially reusable. Accordingly, waste can be even further minimized since disposal of only the portion of the absorbent article that retains the absorbed fluids/exudates following use may be required.

[0016] The objectives set forth herein are achieved by the present absorbent article as defined in the appended claims.

[0017] Accordingly, there is provided an absorbent article comprising a liquid permeable topsheet, a liquid impermeable backsheet, an absorbent core arranged between the topsheet and the backsheet, and a fluid flow control structure arranged between the topsheet and the absorbent core. Further, the fluid flow control structure comprises a first layer which comprises an apertured three- dimensional film formed from regenerated cellulose. The absorbent article may be disposable, which means that the article is intended for a single use and disposed thereafter, instead of being cleaned and reused. The absorbent article may also be an absorbent article comprising a reusable outer cover and a disposable absorbent insert detachably attached to the outer cover.

[0018] Due in part to its arrangement between the topsheet and the absorbent core, the fluid flow control structure facilitates liquid handling into and within the absorbent article. In particular, the fluid flow control structure facilitates initial intake and distribution of absorbed fluid(s) by providing a space in which discharged fluid(s) can be rapidly captured and temporarily stored. Discharged fluid(s) readily pass through the topsheet, are wicked away from its top surface that face the wearer, and are absorbed into the liquid acquisition structure. This means that the absorbed fluids are not in contact with the wearer’s skin and thus may provide the wearer with a feeling of dryness.

[0019] The fluid flow control structure is also designed to moderate the flow of absorbed fluid therethrough and into the absorbent layer(s) (e.g., absorbent core) arranged thereunder. By controlling the flow of fluid through the fluid flow control structure, the absorbent layer(s) may be given time to process and efficiently distribute the absorbed fluids to make full and effective use of the entire absorbent core. This provides efficient fluid management during use of the absorbent article regardless of any one or more of variance in the volume (e.g., high to low; low to high; moderate, etc.) of the discharge, whether the influx of fluid(s) is continuous or discontinuous (e.g., individual insults), the number of instances of fluid influx, and the saturation level of absorbed fluids in the absorbent article.

[0020] In terms of structure, the fluid flow control structure has at least a first layer that comprises an apertured three-dimensional film. The three-dimensional film is formed from a sustainable material, such as regenerated cellulose. In addition to environmental benefits attainable from using sustainable material(s) as a source material, both on the lifecycle of the absorbent articles described herein and the resources required to manufacture them, such sustainable materials have also been shown to provide structural advantages. For example, when provided in the form of an apertured three-dimensional film as described herein, regenerated cellulose demonstrates relatively high resilient properties. Stated in different terms, when formed from regenerated cellulose, it is possible to obtain a three-dimensional film that exhibits a relatively high resistance to compression.

[0021] Having a fluid flow control structure that is resilient and/or has a relatively high resistance to compression, by extension, enables the liquid acquisition structure to maintain its relative thickness (in the z-direction) even when subjected to compressive forces which may occur during normal use of the absorbent article. This resilience to compression and retention of the overall thickness of the liquid acquisition structure further facilitates the provision and maintenance of a space arranged between the topsheet layer and absorbent layer(s) in which absorbed fluids can be retained with minimal to no risk of being released back to the surface of the topsheet and into contact with the wearer’s skin. Additionally, the resilience to compression and retention of the overall thickness of the liquid acquisition structure may, in certain non-limiting embodiments, further serve to counteract and/or compensate for a decrease in the overall absorbent capacity and/or fluid retention level arising from substituting non-plastic material(s) in place of one or more conventional synthetic materials (e.g., non-plastic SAP for synthetic SAP) in one or more other layers of the absorbent article.

[0022] In non-limiting exemplary embodiments, the apertured three-dimensional film may comprise a plurality of apertures and a plurality of protuberances. Each aperture has a three- dimensional shape and a width in a transverse direction along a transverse axis (x) between opposing first and second side walls. Each aperture also extends a length in a thickness direction along a z-axis between a top end and a bottom end. In addition, each aperture is arranged in between adjacent protuberances in the transverse direction. Both the protuberances and the apertures may assist to direct the flow absorbed fluid into and through the fluid flow control structure. The protuberance and the apertures may also, in certain non-limiting exemplary embodiments, be arranged to restrict or deter fluid that has been absorbed into the absorbent article back through the fluid flow control structure toward the topsheet.

[0023] In non-limiting exemplary embodiments, the protuberances are preferably arranged such that the top end is arranged adjacent or proximal to the topsheet and the bottom end is arranged adjacent or proximal to the absorbent core. As noted above, the apertures and the protuberances may be arranged in order to advantageously direct the flow of absorbed fluid(s) away from the topsheet and into the absorbent core. [0024] The apertures are also generally sized to facilitate fluid transport via capillary action through fluid flow control structure and to deter reverse flow of absorbed fluid(s) back through the fluid flow control structure toward the topsheet. As such, the apertures and the protuberances may contribute to minimizing the occurrence of surface wetness at the wearer facing of the topsheet, and by extension, improving rewet performance of the absorbent article.

[0025] In certain non-limiting embodiments, at least most of the apertures being funnel shaped, having a width that preferably tapers from a maximum transverse width at the top end to a minimum transverse width at the bottom end. According to another embodiment each aperture has a funnel shape. In such non-limiting embodiments, it further follows that each aperture may preferably have a width that tapers from a maximum transverse width at the top end to a minimum transverse width at the bottom end. Apertures having a funnel shape may hinder fluid flow back through the liquid acquisition structure and toward the topsheet, even when pressure, such as a compressive force, is applied to the layers of the absorbent article, thereby advantageously contributing to the retention of absorbed fluids in the absorbent article.

[0026] The apertured three-dimensional film may, in certain non-limiting embodiments, have a surface weight in a range of from 20 to 50 gsm, preferably from 25 to 40 gsm, and most preferably from 27 to 37 gsm. However, it is to be understood that the surface weight of the three-dimensional film may be adapted by one of ordinary skill in the art depending on any one or more of the type of absorbent article, the intended use of the absorbent article, the number layer(s) forming the absorbent article, and the source material(s).

[0027] In exemplary non-limiting embodiments, the apertured three-dimensional film may comprise 5 to 60 apertures per cm². Preferably the apertured three-dimensional film may comprise 15 to 45 apertures per cm². The apertures may have circular shape or the apertures may have a diameter being larger in the machine direction than in the cross direction so that the apertures have an oval shape, e g 0.1 to 3.0 mm in the machine direction and 0.1 to 2.0 in the cross direction.

[0028] Similar to the fluid flow control structure, the absorbent core may also comprise sustainable materials. Particularly, it may be preferable in some non-limiting exemplary embodiments that the absorbent core is sourced from material(s) that is/are non-plastic and/or are plastic-free. For example, the absorbent core may comprise materials such as those including but not limited to cellulose fibers and cellulose-based superabsorbent materials derived from renewable resources such as cellulose, starch, chitosan, protein, alginate, pectin, sugar or the like.

[0029] At least one of the topsheet and the backsheet may also comprise material(s) that is/are derived from renewable resources. Like the liquid acquisition structure and/or the absorbent core, one or both of the topsheet and the backsheet may be sourced from renewable material(s), including but not limited to cellulose, starch, chitosan, protein, alginate, pectin or sugar.

[0030] The fluid flow control structure may have a thickness in the z-direction of 0.5 to 2.0 mm, or preferably of 0.5 to 1.2 mm at an applied pressure of 2 kPa.

[0031] Further, in certain exemplary embodiments, the thickness of the fluid flow control structure at an applied pressures of 2 kPa may be at least 70% of a thickness of the fluid flow control structure at an applied pressure of 1 kPa. [0032] The absorbent articles described herein include a fluid flow control structure that comprises at least a first layer. However, it is contemplated that such fluid flow control structures may also comprise, in non-limiting exemplary embodiments, one or more additional layers. Further, it is envisioned in such exemplary embodiments in which the liquid acquisition structure comprises one or more additional layers, that the liquid acquisition structure may be provided in the form of a laminate.

[0033] For example, in certain non-limiting embodiments, the fluid flow control structure may be a laminate which may further comprise a second layer. Further, it may be preferable, when the liquid acquisition structure comprises a second layer, that the second layer may be a nonwoven layer. It may be further preferable still that the second layer is a nonwoven layer made from non-plastic material(s) such as regenerated cellulose, cotton, lyocell, kapok and/or hemp or the like

[0034] It is further contemplated that, in some non-limiting exemplary embodiments, the first layer of fluid flow control structure may be arranged adjacent or most proximal to the topsheet. Alternatively, in some other non-limiting exemplary embodiments, the second layer of fluid flow control structure may be arranged adjacent or most proximal to the topsheet. Specific of arrangement of the first and second layers may be determined based on any one or more of the type of absorbent article, the intended use thereof, the total number of layer(s) forming the absorbent article.

[0035] Further still, in embodiments in which the fluid flow control structure is a laminate of a first layer and a second layer, such laminate may additionally comprise a third layer. When provided, the third layer may, like the second layer, be another nonwoven layer. It may be further preferable still that the second layer is a nonwoven layer made from non-plastic material(s) such as regenerated cellulose, cotton, lyocell, kapok and/or hemp or the like.

[0036] As indicated above the absorbent articles described herein may be provided in any one of a number of different forms, including but not limited to a sanitary towel, a sanitary napkin, a panty liner, an incontinence pad, and an incontinence liner. It also envisioned, in certain exemplary nonlimiting embodiments, that the absorbent article(s) may comprise(s) a reusable part and a disposable part. More specifically, the reusable part may comprise a reusable outer cover that is preferably washable, and the disposable part may comprise a disposable insert that comprises the resilient liquid acquisition structure and is preferably single-use. In such non-limiting embodiments, it is to be understood that the reusable part and the disposable part are removably attached to each other; attachment of the reusable part and the disposable part may be by any suitable attachment means, such as a button and/or snap closure, a hook and loop closure, or the like. Following use, the disposable part may thus be detached from the reusable part so that it may be disposed of quickly and easily. Meanwhile, the reusable part may be cleaned and/or attached to a new disposable part. [0037]

Method description and result

Compressibility under a sequence of pressures (0.5kPa, 1 .0 kPa and 2.0 kPa) has been evaluated according to following method. The tested sample had been conditioned for at least four hours in a controlled environment set to 23°C +/- 1 °C and 50% +/- 5% relative humidity. When conditioning, single layers of the material had been rested flat and exposed. Testing took place in this same environment. A representative sample had been arranged flat on an even surface, and a spot had been selected for thickness measurement. A thickness gauge foot (a square measuring 5 x 5 cm) exerting a pressure of 0.5 kPa was gently lowered onto the sample. The thickness was read when the foot had rested on the material for 5 seconds, after which the foot was lifted. After a waiting time of one minute the thickness was measured again on the same spot, but now with a foot exerting a pressure of 1 .0 kPa. A minute later a final measurement was made under a pressure of 2.0 kPa.

[0038] Tested sample was a perforated film of 100% regenerated cellulose. The basis weight was 37 gsm and the sample had 7 apertures/cm².

[0039] Thickness result

The thickness of the tested sample at an applied pressure of 2 kPa was 78% of the thickness at an applied pressure of 1 kPa.

[0040] Further objectives, features and advantages of the present absorbent article are described in the detailed description below with reference to the appended drawings.

Brief description of the drawings

[0041] The present invention will be discussed in more detail below, with reference to the attached drawings, in which:

[0042] Figure 1 shows a cross-section of an exemplary absorbent article according to the present disclosure;

[0043] Figure 2 shows an exemplary fluid flow control structure; and

[0044] Figures 3A-D each show an exemplary fluid flow control structure according to the present disclosure in combination with one or more additional layers.

Detailed description

The absorbent articles described herein are absorbent articles aimed for personal hygiene and may be, for example, a sanitary towel or sanitary napkin, a panty liner, an incontinence pad, an incontinence liner or a diaper. Such articles are commonly used for the acquisition and storage of discharged bodily exudates such as urine and menstrual fluid. The absorbent articles may be disposable, which means that they are intended for a single use and disposed thereafter, instead of being cleaned and reused. The absorbent article may also be an absorbent article comprising a reusable outer cover and an absorbent insert detachably attached to the outer cover.

[0045] A cross-section of an exemplary absorbent article in accordance with the present disclosure is shown Figure 1 . The absorbent article generally comprises four components: a liquid permeable topsheet 1 , a fluid flow control structure 2, an absorbent core 3, and a liquid-impermeable backsheet 4. Structurally, the fluid flow control structure 2 and the absorbent core 3 are arranged between the topsheet 1 and the backsheet 4, with the fluid flow control structure 2 arranged adjacent to the topsheet 1 and the absorbent core 3 arranged adjacent to the backsheet 4.

[0046] The topsheet 1 lies in direct contact with the wearer’s body and should therefore be soft and comfortable. The topsheet 1 can comprise a nonwoven material, e.g. spunbond, meltblown, carded, hydroentangled, wetlaid, etc. Suitable nonwoven materials may be composed of natural fibers, such as regenerated cellulose (viscose and/or lyocell), cotton, kapok, hemp or the like. Apertured films may also be used as topsheet 1 materials. In any case, suitable topsheet 1 materials should be soft and non-irritating to the skin and be readily penetrable by bodily fluids, e.g. urine or menstrual fluid.

[0047] The backsheet 4 lies in contact with the wearer’s garments. The backsheet 4 refers to the liquid impervious material forming the outer cover of the hygiene article. The backsheet 4 can comprise a thin 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. The backsheet 4 material may be breathable so as to allow vapor to escape from the absorbent core, while still preventing liquids from passing there through. Examples of breathable backsheet 4 materials are porous polymeric films nonwoven laminates of spunbond and meltblown layers and laminates of porous polymeric films and nonwoven materials. Suitable nonwoven materials may be composed of natural fibers, such as regenerated cellulose (viscose and/or lyocell), cotton, kapok, hemp or the like. Suitable polymeric films may be composed of biobased PE, starch, PLA, PHA, PBAT or the like.

[0048] It is also contemplated that the backsheet 4 may be provided with one or more additional optional elements, such as a release paper and/or plastic wrap (not shown). The release paper and/or plastic wrap may be used to protect the backsheet 4, particularly in embodiments having an adhesive or attachment element on the garment-facing side of the backsheet 4, during transport and/or storage of the assembled absorbent article prior to use thereof.

[0049] The absorbent core 3 is the absorbent structure of the article which acquires and stores bodily fluids and exudates. The absorbent core 3 may be of any conventional kind. Examples of commonly occurring absorbent materials are cellulosic fluff pulp, tissue, highly absorbent polymers (so called superabsorbents), absorbent nonwoven materials or the like. It is common to combine cellulosic fluff pulp with superabsorbent polymers in an absorbent core 3. Superabsorbent polymers are water-swellable, water-insoluble organic or inorganic materials capable of absorbing at least about 20 times their own weight of an aqueous solution containing 0.9 weight percent of sodium chloride. With the movement away from conventional plastic-based source materials, organic materials suitable for use as a superabsorbent material can include natural materials such as cellulose, starch, chitosan, protein, alginate, pectin, sugar and the like. The superabsorbent materials may be in any form suitable for use in absorbent composites including particles, fibers, flakes, spheres, and the like. The size and absorbent capacity of the absorbent core may thus be varied to suit different product types, such as sanitary napkins for adult incontinent persons or panty liners.

[0050] In certain embodiments, the absorbent core 3 can be of unitary construction, whereby for example the manufacturing process can be simplified. The phrase "unitary construction" in the present context is intended to mean that the absorbent core is 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 absorbent core. Variations in density and concentration of the material may occur, but these are limited to those which may be obtained without incorporation of regions which have been formed separately and then physically joined to each other. For example, when the absorbent core comprises a matrix of hydrophilic fibers and superabsorbent material as described above, the relative concentrations of superabsorbent material and fibers may be different in different parts of the core. However, an absorbent core 3 of unitary construction does not comprise layers or laminates of different composition. Likewise, variations in the density or concentration of various components across the longitudinal direction, the transverse direction or the thickness direction of the absorbent core are acceptable, yet the absorbent core 3 should not comprise areas or layers of different composition which are formed separately and later joined together.

[0051] In some non-limiting embodiments, the absorbent core 3 can have a multi-layered structure. In this sense, the absorbent core 3 can comprise a plurality of absorbent layers and/or absorbent members. When the absorbent core 3 comprises a plurality of absorbent layers and/or absorbent members, the absorbent layers and/or absorbent members may be equally sized or may differ in one or more dimensions.

[0052] The fluid flow control structure 2 is a layer that can be arranged between the topsheet 1 and the absorbent core 3 and may suitably be placed on top of the absorbent core 3. The fluid flow control structure 2 is adapted to quickly receive and temporarily store discharged fluid before it is absorbed by the absorbent core 3.

[0053] Figure 2 depicts an exemplary fluid flow control structure 20 in accordance with the present disclosure. In this non-limiting example, the liquid acquisition structure 20 is provided in the form of a single layer that comprises a three-dimensional film 20. A sustainable material, such as regenerated cellulose, is used to form the three-dimensional film.

[0054] Structurally, the three-dimensional film has a number of protuberances 201 . As can be seen in Fig. 2, each protuberance is formed with a pair of opposing side walls 2011 A, 2011 B that are spaced a distance apart from each other in the transverse direction along a transverse axis (x) of the film. The width of each protuberance 201 can be defined by this distance in the transverse direction between its opposing side walls 2011 A, 2011 B. Further, each protuberance also has a respective height between a top end 2012 and a bottom end 2013 in a thickness direction along a z-axis of the film.

[0055] The respective top ends 2012 of the protuberances 201 are closed structures and contribute to controlling the flow of fluid through the fluid flow control structure 20. The closed tops assist to direct the flow into apertures 202 that are arranged between the side walls 2011 A, 2011 B of adjacent pairs of protuberances 201 .

[0056] As is shown in the figure, the apertures 202 may have a funnel shape, and it further follows in such instances that the apertures 202 also have a width in the transverse direction (x) that tapers from a maximum transverse width to a minimum transverse width. In certain non-limiting exemplary embodiments, it may be preferred that the maximum transverse width of the aperture 202 is arranged in the z-direction between the side walls 2011 A, 2011 B at the respective top ends 2012 of two adjacent protuberances 201 , and conversely, the minimum transverse width of the aperture 202 is arranged between the side walls 2011 A, 2011 B at the respective bottom ends 2013 of the two adjacent protuberances 201 . By way of this arrangement, absorbed fluids may be funnelled in from the topsheet 1 through the fluid flow control structure 2, 20 and into the absorbent layer(s) there under. Besides, having the maximum transverse width of the apertures 202 arranged proximal to the fluid intake side (i.e., closer to the topsheet) facilitates a larger ingress of fluid upon intake. Inversely, having the minimum transverse width of the apertures 202 arranged proximal to the absorbent layer(s) below the fluid flow control structure 2, 20 may contribute to promoting increased fluid retention since passage of the absorbed fluids back through the fluid flow control structure 2, 20 is more restricted from re-entry into the aperture 202 by the narrowed minimum transverse width. [0057] In certain non-limiting exemplary embodiments, the funnel-shaped apertures 202 at the top end 2012 of the nonwoven layer have a transverse width being relatively larger in size than the transverse widths of the apertures 202 between the side walls 2011 A, 2011 B at the respective bottom ends 2013 . The funnel-shaped apertures 202 may help to facilitate retention of absorbed fluid(s) and deter the same from passing back through the fluid flow control structure 2, 20 toward the topsheet 1 and into contact again with the wearer. This may encourage absorbed fluid to flow into the open space in the three-dimensional film layer between the apertures 202, rather than back through the relatively narrow transverse minimum width of the apertures 22.

[0058] In certain non-limiting exemplary embodiments, the fluid flow control structure 2 may comprise also one or more layers in additional to the three-dimensional film. Exemplary fluid control structures 2 having one or more such additional layers are depicted in each of Figures 3A-3D.

[0059] For example, Fig. 3A shows a fluid flow control structure 2 that is a laminate which comprises a first layer 21 and a second layer 22. Similar to the exemplary fluid flow control structure 2, 20 illustrated in Fig. 2, the first layer of the fluid flow control structure of Fig. 3A comprises a three-dimensional film which comprises a number of apertures. A plurality of protuberances are arranged between the side walls of two adjacent apertures in the transverse direction (x). Again, these exemplary apertures are generally funnel-shaped and are arranged with their maximum transverse width at a top side of the first layer, proximal to the topsheet (not shown) of the absorbent article, and their minimum transverse width at a bottom side of the first layer, proximal to the absorbent core (not shown) of the absorbent article. Furtherto this three-dimensional film, a second layer 22 is shown laminated to the bottom side of the first layer. In certain non-limiting embodiments, it may be preferable that the second layer is a nonwoven layer.

[0060] Fig. 3B shows another fluid flow control structure that is a laminate which comprises a first layer 21 and a second layer 22. Similar to the exemplary fluid flow control structure 2,20 illustrated in Fig. 2, the first layer 21 of the fluid flow control structure of Fig. 3B also comprises a three- dimensional film which comprises a number of apertures and a plurality of protuberances that are arranged between the side walls of two adjacent apertures in the transverse direction (x). Once again, these exemplary apertures are generally funnel-shaped and are arranged with their maximum transverse width at a top side of the first layer, proximal to the topsheet (not shown) of the absorbent article, and their minimum transverse width at a bottom side of the first layer, proximal to the absorbent core (not shown) of the absorbent article. Different from the fluid flow control structure illustrated in Fig. 3A, the second layer 22 in this non-limiting embodiment is laminated to the top side of the first layer. However, like Fig. 3A, the second layer may, in certain non-limiting embodiments, be a nonwoven layer.

[0061] Fig. 3C depicts yet another fluid flow control structure that is a laminate. In this example, however, the laminate comprises three layers a first layer 21 , a second layer 22, and third layer 23. Here, the first layer 21 of the fluid flow control structure comprises a three-dimensional film with a plurality of apertures and a plurality of protuberances likes the other fluid flow control structures shown in Figs. 2, 3A, and 3B. Both of the additional second 22 and third layers 23 may, in certain non-limiting exemplary embodiments, be provided in the form of a nonwoven layer. Further, each additional layer is laminated to one side of the three-dimensional film. In this sense, the three- dimensional film is sandwiched between the second and third layers and does not directly contact either of the topsheet (not shown) or an absorbent layer (e.g., the absorbent core) (not shown).

[0062] Finally, Fig. 3D illustrates yet one more fluid flow control structure that is formed as a laminate of three layers. The first layer 21 of the fluid flow control structure once again is the layer that comprises a three-dimensional film with a plurality of apertures and a plurality of protuberances likes the other fluid flow control structures shown in Figs. 2, 3A, 3B, and 3C. Here, the additional second 22 and third layers 23, which may be, in some non-limiting exemplary embodiments, provided in the form of a nonwoven layer, are stacked together. In this sense both of the second and third layers are laminated on the same side of the three-dimensional film one layer on top of another. In this example, the second layer 22 is sandwiched between the first layer 21 and the third layer 23. As such, the top side of the first layer may be arranged proximal to and/or in direct contact with the topsheet (not shown) while the bottom side of the third layer may be arranged proximal to and/or in direct contact with an absorbent layer (e.g., the absorbent core) (not shown).

[0063] It is to be understood that it is also contemplated for any embodiment of the absorbent articles described herein that the fluid flow control structure 2, 20 may be suitably dimensioned in the transverse and longitudinal directions (x, y) as desired, for example, based on the type and/or application of the absorbent article, by one of ordinary skill. In one non-limiting exemplary embodiment, the fluid flow control structure 2, 20 may have a length in the longitudinal direction (y) and a width in the transverse direction (x) that are equal to or shorter than a respective length and respective width of the absorbent core.

[0064] Additionally, it is envisioned that the absorbent articles described herein may, in some nonlimiting exemplary embodiments, be at least partially reusable. In this sense, these exemplary absorbent articles may comprise a reusable part and a disposable part. The reusable part may comprise a reusable outer cover that is preferably formed from material(s) that is/are washable. The disposable part may be in the form of a disposable insert that comprises a resilient liquid acquisition structure as described herein. It should be understood that the disposable part and the reusable part are removably attached to each other by any suitable attachment means. Accordingly, the disposable part can be detached from the reusable part following use and may be quickly and easily disposed of by a user. In the meantime, the reusable part may be cleaned (e.g., washed) and/or may be attached to a new disposable insert for continued use.

[0065] While the invention has been described herein by reference to certain embodiments, it is to be understood that modifications in addition to those described herein may be made to the structures and techniques described herein without departing from the spirit and scope of the invention. Accordingly, although specific embodiments have been described, they are examples only and are not limiting upon the scope of the invention.

Claims

Claims

1 . An absorbent article comprising a liquid permeable topsheet (1), a liquid impermeable backsheet (4), an absorbent core (3) arranged between the topsheet (1) and the backsheet (4), and a fluid flow control structure (2, 20) arranged between the topsheet (1) and the absorbent core (3), wherein the fluid flow control structure (2, 20) comprises a first layer (21) comprising an apertured three- dimensional film formed from regenerated cellulose.

2. The absorbent article according to claim 1 , wherein the apertured three-dimensional film is a three-dimensional formed layer having penetrating apertures (202), the apertures (202) being funnel-shaped and each aperture (202) having a width in a transverse direction along a transverse axis (x) between opposing first and second side walls (2011 A, 2011 B) and extending a length in a thickness direction along a z-axis between a top end (2012) and a bottom end (2013).

3. The absorbent article according to claim 2, wherein the top end (2012) is arranged adjacent or proximal to the topsheet (1) and the bottom end (2013) is arranged adjacent or proximal to the absorbent core (3).

4. The absorbent article according to claim 2 or claim 3, wherein the apertures (202) having a width that preferably tapers from a maximum transverse width at the top end (2012) to a minimum transverse width at the bottom end (2013).

5. The absorbent article according to any one of the preceding claims, wherein the apertured three- dimensional film has a surface weight in a range of from 20 to 50 gsm, preferably from 25 to 40 gsm, and most preferably from 27 to 37 gsm.

6. The absorbent article according to any one of claims 2 to 5, wherein the bottom end (2013) of each funnel-shaped aperture (202) has a diameter of between 0.25 mm to 2.0 mm.

7. The absorbent article according to any one of the preceding claims, wherein the apertured three- dimensional film comprises 5 to 60 apertures per cm².

8. The absorbent article according to any one of the preceding claims, wherein the absorbent core (3) comprises cellulose fibers and superabsorbent materials derived from renewable resources, such as cellulose, starch, chitosan, protein, alginate, pectin or sugar or a combination thereof.

9. The absorbent article according to any one of the preceding claims, wherein at least one of the topsheet (1) and the backsheet (4) comprises a material derived from renewable resources, such as cellulose pulp, viscose, lyocell, cotton, hemp, kapok, flax, starch, chitosan, protein, alginate, pectin or sugar or a combination thereof.

10. The absorbent article according to any of the preceding claims, wherein the fluid flow control structure (2, 20) has a thickness in a z-direction of 0.5 to 1 .2 mm at an applied pressure of 2 kPa.

11. The absorbent article according to any of preceding claims, wherein the thickness of the fluid flow control structure (2, 20) at an applied pressure of 2 kPa is at least 70% of a thickness of the fluid control structure (2,20) at an applied pressure of 1 kPa.

12. The absorbent article according to any of the preceding claims, wherein the fluid flow control structure (2, 20) is a laminate that further comprises a second layer (22).

13. The absorbent article according to claim 12, wherein the second layer (22) is a nonwoven layer.

14. The absorbent article according to claim 12 or claim 13, wherein the first layer (21) of the fluid flow control structure (2, 20) is arranged adjacent or most proximal to the topsheet (1).

15. The absorbent article according to claim 12 or claim 13, wherein the second layer (22) of the fluid flow control structure (2, 20) is arranged adjacent or most proximal to the topsheet (1).

16. The absorbent article according to any one of claims 12 to 15, wherein the laminate further comprises a third layer (23).

17. The absorbent article according to claim 16, wherein the third layer (23) is a nonwoven layer.

18. The absorbent article according to any of preceding claims, wherein the apertured three- dimensional film has a thickness of 0.5 to 1 .5 mm at an applied pressure of 0.5 k Pa, preferably a thickness of 0.7 to 1 .2 mm at an applied pressure of 0.5 k Pa.

19. An absorbent article having an absorbent insert and a reusable outer cover, wherein the absorbent insert is adaptable to be detachably secured in the reusable outer cover and comprising the fluid flow control structure (2, 20) according to any of claims 1-18.