Absorbent article with apertured layer

Abstract

The present invention relates to an absorbent article comprising a topsheet, a backsheet, an absorbent core positioned between the topsheet and the backsheet, and an apertured layer positioned between the topsheet and the absorbent core, wherein the topsheet has an opacity of from about 15% to about 40% as determined by the Opacity Measurement Method, wherein the apertured layer comprises a plurality of apertures, each aperture having an individual apertured area of from about 0.4 mm 2 to about 25 mm 2 , or about 0.5 mm 2 to about 15 mm 2 , or 1 mm 2 to about 10 mm 2 , wherein adjacent apertures are spaced apart by an edge-to-edge distance of from about 1 mm to about 7 mm, or from about 2 mm to about 5 mm, or from about 4 mm to about 6 mm as determined by the Aperture Measurement Method.

Description

Technical Field

[0001] This invention relates to absorbent articles, and more particularly to feminine hygiene articles, which include an open-cell layer having specific pores designed to enhance the user’s perception of breathability and comfort. Background Technology

[0002] Absorbent products such as menstrual pads, period panties, diapers, and linings are designed to absorb and retain bodily fluids, thereby keeping the wearer's skin dry and comfortable. A typical construction of such absorbent products includes several layers that provide different functions. For example, an absorbent product may include a body contact surface, often referred to as a topsheet, a fluid-impermeable layer (referred to as a backsheet) that comes into contact with the woman's clothing, and an absorbent core positioned between them. Typically, an additional fluid-collecting or management layer is placed between the topsheet and the core to facilitate fluid distribution.

[0003] Nonwoven fabrics are commonly used as topsheets because they provide a skin-friendly surface. However, nonwoven topsheets may not function adequately, and consumers may have an unpleasant experience due to improper fluid handling. To address this issue, it has been proposed to provide pores in the nonwoven topsheet to help bodily fluids permeate the nonwoven topsheet and the underlying absorbent core. These conventional designs may be perceived as rough, less aesthetically pleasing, and may not effectively convey a sense of breathability or comfort.

[0004] Beyond mere functionality, the overall appearance and sensory / perceptual quality of absorbent products are key aspects guiding consumers' choices among the various commercially available absorbent products. A positive overall sensory experience is believed to be one of the key factors in consumer preference.

[0005] In order to modulate the overall sensory experience of consumers, attempts have been made to design absorbent articles that can deliver improved perceived breathability and improved confidence levels for absorbent articles.

[0006] However, there is still a need for an absorbent product that not only functions but also provides an improved visual appearance and superior breathability and perceived quality, which are key factors in consumer preference and confidence. Summary of the Invention

[0007] This invention provides an absorbent article comprising a top sheet, a bottom sheet, an absorbent core positioned between the top sheet and the bottom sheet, and an open-cell layer positioned between the top sheet and the absorbent core. The top sheet has an opacity of approximately 15% to approximately 40%, as determined by the opacity measurement method described herein. The open-cell layer comprises a plurality of pores, each pore having an opacity of approximately 0.4 mm, as determined by the pore measurement method. 2 approximately 25mm 2 or about 0.5mm 2approximately 15mm 2 or about 1mm 2 approximately 10mm 2 The opening area, wherein adjacent holes are spaced apart by an edge-to-edge distance of about 1 mm to about 7 mm, or about 2 mm to about 5 mm, or about 4 mm to about 6 mm as determined by the hole measurement method disclosed herein.

[0008] This combination provides the solution required as mentioned above.

[0009] Depending on various aspects, absorbent articles include one or more of the following characteristics, which should be considered in any possible combination of techniques:

[0010] - Each hole has an aspect ratio of approximately 1 to approximately 3, or approximately 1.5 to approximately 2.

[0011] - The aperture layer comprises approximately 6% to approximately 20% of the total aperture area.

[0012] - Each hole has a depth of 0.8mm to 3mm, or 0.9mm to 1.5mm.

[0013] - The porous layer includes pores that are distributed throughout the entire surface of the layer.

[0014] - The absorbent article includes a longitudinal axis and a lateral axis perpendicular to the longitudinal axis, the longitudinal axis and the lateral axis intersecting at point P, wherein the open layer includes the intersection point and covers at least 30% of the total surface area of ​​the absorbent core.

[0015] - Multiple holes have shapes selected from circles, ovals, triangles, squares, rectangles, parallelograms, trapezoids, polygons, hourglasses, and stars.

[0016] - The perforated layer is an open-cell nonwoven layer.

[0017] - The perforated layer is the fluid management layer, and / or

[0018] -Absorbent products are sanitary napkins or underwear.

[0019] These and other features, aspects, and advantages of the invention will become apparent to those skilled in the art upon reading this disclosure. For ease of discussion, the absorbent articles will be discussed with reference to the reference numerals mentioned in the accompanying drawings. However, unless explicitly indicated otherwise, the drawings and detailed descriptions should not be considered to limit the scope of the claims. Attached Figure Description

[0020] Figure 1 A perspective view of feminine hygiene products is shown;

[0021] Figure 2A schematic diagram illustrating an exemplary process for opening a precursor fiber web is shown.

[0022] Figure 3 yes Figure 2 An enlarged view of an exemplary hole-opening process.

[0023] Figure 4A and Figure 4B This is a diagram illustrating the arrangement and spacing of holes according to a non-limiting embodiment of the present invention.

[0024] Figure 5 A perspective view of another embodiment of a feminine hygiene product with a patch is shown. Detailed Implementation

[0025] All ranges are inclusive and combinable. The number of significant digits does not limit the quantity indicated or the precision of the measurement. All numerical values ​​should be understood to be modified by the word "about" unless otherwise specified.

[0026] As used herein, the term "comprising" means various components, ingredients, or steps that may be combined and applied in the course of carrying out the invention. Therefore, the term "comprising" is an open-ended term and includes the more restrictive terms "consistently consisting of" and "consisting of".

[0027] As used herein, the term "absorbent article" refers to a device for absorbing and containing bodily excretions, and more specifically, a device placed close to or adjacent to the wearer's body to absorb and contain various bodily excretions. Absorbent articles include, but are not limited to, diapers, training pants, absorbent pads, incontinence pants or pads, linings, sanitary napkins, etc., for premature infants, babies, children, or adults. Typically, these absorbent articles include a top sheet, a bottom sheet, an absorbent core, and optionally a collection layer or fluid management layer, wherein the absorbent core is usually at least partially placed between the bottom sheet and the collection layer or fluid management layer.

[0028] As used herein, the terms "nonwoven fabric," "nonwoven layer," or "nonwoven substrate" refer to a fiber web having a layered, single-fiber or spun structure but not exhibiting a repeating pattern as in woven or knitted fabrics, which typically do not have randomly oriented fibers. Nonwoven materials and methods for preparing them are known in the art. Nonwoven fabrics can be produced by any known procedure for manufacturing nonwoven fiber webs, non-limiting examples of which include processes such as carding (carding hot air penetration), wet web forming, air-blowing, meltblowing, needle punching, mechanical winding, thermo-mechanical winding, and hydroentangling. Nonwoven fabrics may include natural fibers, synthetic fibers, or combinations thereof. Fibers may be short fibers or continuous filaments or formed in situ. Synthetic fibers may include polymeric materials, including polyolefins (such as polyethylene (PE) and polypropylene (PP)), polyamides, and polyesters (such as polybutylene terephthalate (PBT) and polyethylene terephthalate (PET)). Synthetic fibers can be in the form of monocomponent, bicomponent, or multicomponent fibers, or shaped, crimped, or any other formulation or configuration known in the art for use with nonwoven substrates and fibers. For example, the nonwoven substrate may include any other suitable type of fiber, such as viscose, rayon, or other suitable nonwoven fibers. These fibers may have any suitable denier or denier range.

[0029] As disclosed herein, a material or substrate that is without pores and prior to processing is referred to as a "precursor substrate".

[0030] The basic weight of nonwoven or woven fabrics is the mass per unit area and is typically expressed in grams per square meter (g / m²). 2 )express.

[0031] The “longitudinal” direction (L) or (MD) is the direction that extends parallel to the maximum linear dimension of the article (typically the longitudinal axis) and includes directions within 45° of the longitudinal direction. When used herein, the “length” of an article or its components generally refers to the size / distance of the maximum linear dimension, or typically to the size / distance of the longitudinal axis of the article or its parts.

[0032] The "lateral" or "transverse" direction (T) is orthogonal to the longitudinal direction, meaning it lies in the same plane as the longitudinal axis of the article and is parallel to the transverse axis. When used herein, the "width" of an article or component refers to the size / distance of a dimension orthogonal to the longitudinal direction of the article or component, i.e., orthogonal to the length of the article or component, and is generally referred to as the distance / size of a dimension parallel to the transverse axis of the article or component.

[0033] The "Z-direction" or "thickness direction" is orthogonal to both the longitudinal and transverse directions. The Z-direction is defined as the direction perpendicular to the surface of the absorbent article. In other words, the Z-direction refers to the direction approximately perpendicular to the machine direction (MD).

[0034] As used herein, the term "hole aspect ratio" is the ratio of the long dimension to the short dimension of a single hole. The term "long dimension" refers to the maximum size of the hole measured from one extreme side to the other.

[0035] The term "short dimension" refers to the second dimension of the hole, which is also measured from one extreme side to the other extreme side but along a direction perpendicular to the long dimension mentioned above.

[0036] As used herein, the term “opening area” or “hole opening area” refers to the average size of the opening area of ​​a single hole as measured in area units (e.g., square millimeters).

[0037] As used herein, the term “total open area” refers to the percentage of the total area of ​​a fiber web or layer with pores.

[0038] The term "interlaced" in relation to holes refers to an arrangement of holes in alternating positions, such that holes in adjacent lateral extension rows are offset by lateral distances and / or holes in adjacent longitudinal extension columns are offset by longitudinal distances, such as... Figure 4B As shown.

[0039] "Opacity" is a measure of a material's ability to obscure the background behind it, as measured by the opacity measurement method described in this article. In short, opacity is measured as a contrast ratio. The light reflectance of the sample is measured when it is placed above standard black and white plates. Opacity is expressed as a percentage of the reflectance on the black plate to the reflectance on the white plate.

[0040] Absorbent products

[0041] refer to Figure 1 The absorbent article according to the invention may be in the form of a sanitary napkin 10. The sanitary napkin 10 includes a fluid-permeable top sheet 11 having a wearer-facing surface and a garment-facing surface positioned opposite the wearer-facing surface. The absorbent article also includes a back sheet 14 having a garment-facing surface and a wearer-facing surface positioned opposite the garment-facing surface, wherein the back sheet 14 is at least partially connected to the top sheet 11. The absorbent article also includes an absorbent core 13 positioned between the top sheet 11 and the back sheet 14. The sanitary napkin 10 also includes an open-cell layer 12 positioned between the top sheet 11 and the absorbent core 13. The open-cell layer may serve as a fluid management layer. The sanitary napkin 10 may also include a pair of flaps or wings 15. The top sheet 11, back sheet 14, fluid management layer 12, and absorbent core 13, as well as other optional elements, may be assembled in various well-known configurations.

[0042] The inventors have surprisingly discovered that a specific combination of a top sheet with a defined opacity and an underlying open-cell layer with a specific pore arrangement produces a visual and sensory effect that is perceived by consumers as more breathable and more attractive in terms of softness and the ability to handle bodily fluids. In other words, the absorbent article according to the invention is more likely to convey improved breathability and performance.

[0043] Specifically, when an absorbent article includes a top sheet having opacity within a given range and includes an open layer with pores having selected individual opening areas and controlled edge-to-edge distances, the resulting absorbent article is accepted by consumers because it provides a superior sense of breathability and improved performance perception.

[0044] It is not intended to be limited to the following interpretation, but the absorbent articles according to this disclosure can provide an improved sensory experience because visual perception is directly translated into the user's sensory experience, thereby making the product feel more comfortable, softer and more efficient in handling fluids.

[0045] Furthermore, it is believed that the absorbent articles according to this disclosure can bring consumers greater trust and satisfaction by exhibiting superior quality and breathability.

[0046] In addition, multiple holes can have a specific aspect ratio that ensures the holes have a visually pleasing shape that contributes to the overall aesthetics.

[0047] Finally, the perforated layer may include a defined total opening area that provides a balanced visual appearance, thereby avoiding a pattern that is too sparse or too crowded.

[0048] Top film

[0049] See Figure 1 The absorbent article according to the invention (e.g., sanitary napkin 10) includes a top sheet 11 having a wearer-facing surface and a garment-facing surface positioned opposite the wearer-facing surface. The top sheet is generally liquid-permeable and configured to receive fluid being expelled from the body and facilitate the guidance of fluid toward the fluid management layer and / or toward the absorbent core. An important quality of the top sheet is its ability to reduce fluid buildup on the top sheet before the fluid can be absorbed by the absorbent article. Another desired quality of the top sheet is reduced backflow. It is also desirable for the top sheet to present a clean user-contact surface with fewer stains. The top sheet in this invention is the portion of the absorbent article that comes into contact with the wearer's skin during use of the article. As known to those skilled in the art, the top sheet may be attached to portions of the bottom sheet, absorbent core, and / or any other layer. The top sheet may be soft, feel fluffy, and be non-irritating to the user's skin.

[0050] The top sheet includes an opacity of approximately 15% to approximately 40%, or including 20% ​​to 30%, as measured by an opacity measurement method. The opacity is measured according to the opacity measurement method disclosed herein.

[0051] It is believed that this specific range of opacity is optimal for visually revealing the underlying perforated pattern because, on the one hand, opacity below 15% would adversely affect the perception of softness, and the masking of colored fluids would be reduced. On the other hand, with opacity above 40%, the observable contrast difference between the top sheet and the underlying perforated layer would be insufficient to achieve the desired breathability and performance perception.

[0052] The top sheet may comprise a nonwoven or woven material. In one aspect, the top sheet may comprise a carded hot air-permeable nonwoven fabric. The nonwoven fabric constituting the top sheet in this disclosure may have a density of approximately 15 g / m². 2 Approximately 80g / m 2 or approximately 20g / m 2 Approximately 70g / m 2 or approximately 25g / m 2 Approximately 60g / m 2 The base weight.

[0053] The topsheet may also optionally include colorants such as pigments, lakes, toners, dyes, inks, or other agents used to impart color to the material. Suitable pigments include inorganic pigments, pearlescent pigments, interference pigments, etc. The topsheet may include multiple embossings to provide a more fabric-like appearance.

[0054] Open layer

[0055] The absorbent article according to this disclosure includes an open-cell layer comprising a plurality of pores. See also Figure 1 The perforated layer is positioned between the top sheet and the absorber core, and can be directly or indirectly placed on the absorber core.

[0056] On the one hand, the perforated layer is either a nonwoven layer or a woven layer.

[0057] Opening layers can be manufactured using any conventional method known in industry, such as pinhole opening, punching opening, needle punching opening, and water jet opening.

[0058] As an example, an open-cell layer can be manufactured by a method including the steps of forming a plurality of pores on a precursor substrate and applying energy to the precursor substrate to increase the bulkiness of the fiber web. For example, a method for producing an open-cell layer may include the steps of supplying a non-open-cell layer unwound from a roll, forming a plurality of pores on the layer via various processes known to those skilled in the art, and then applying heat to the resulting layer to restore the bulkiness of the layer. In the context of this disclosure, pores are formed by an opening process and therefore must be distinguished from layers that have not undergone an opening process and only have small pores (not pores for the purposes of this disclosure).

[0059] Figure 2 This is a schematic diagram of a mechanical hole-making process as an example of a hole-forming process. Figure 3 yes Figure 2 Rollers 22 and 23 and thus through Figure 2 An enlarged view of the hole 40 produced by the illustrated process.

[0060] refer to Figure 2 and Figure 3 The precursor substrate 25 passes through a roll gap 21 formed by a pair of rollers 20 and two intermeshing rollers 22 and 23 to form an open layer 24 including holes 40. The first roller 22 may include a plurality of first elements, such as protrusions 26, extending outwardly from the first roller 22. The first elements on the first roller 22 can vary widely in size, shape, height, area, width, and / or dimension, which may define the size, shape, and dimension of the deformable portions, such as the holes. The second roller 23 may have a flat surface, or the second roller 23 may include grooves that intermesh with the protrusions of the first roller 22. When the precursor substrate 25 comprises thermoplastic fibers, at least one of the rollers 22 and 23 may be heated to a temperature sufficient to soften the fibers constituting the precursor substrate 25, but below the melting point of the fibers. When the fibers comprise a sheath / core type dimer, at least one of the rollers 22 and 23 may be heated to a temperature above the melting point of the sheath polymer. The first roller 22 may include a plurality of first forming elements, such as teeth, and a plurality of second recesses formed in the radially outer surface of the first roller 22. The second roller 23 may include a plurality of second forming elements extending radially outward from the second roller 23, the plurality of second forming elements being configured to at least partially engage with the second recesses in the first roller 22.

[0061] The size, shape, height, area, width, and / or dimensions of the multiple pores in the layer can vary. In one aspect, the open-cell layer includes pores having substantially the same size, shape, height, area, width, and / or dimensions, such that the size of one pore is almost unchanged compared to another pore within a given open-cell layer.

[0062] exist Figure 4A and Figure 4B An example of an open-cell layer according to the present invention is illustrated below. Figure 4A and Figure 4B An example of multiple holes 40 is shown, wherein each hole has a major axis corresponding to a long dimension (e.g., length), a minor axis corresponding to a short dimension (e.g., width), and a center point C corresponding to the intersection of the major and minor axes.

[0063] Figure 4A This is an illustration of a portion of an open layer comprising a plurality of holes arranged according to a first pattern. The first pattern is such that the holes are aligned in rows in the longitudinal direction and in columns in the lateral direction to form a grid pattern. In this configuration, the center point C of each hole is aligned with the center point C of the adjacent hole in the longitudinal direction, and the center point of the hole is aligned with the center point C of the adjacent hole in the lateral direction. In other words, the center of each hole is aligned with the center of the adjacent hole in the longitudinal direction, and the center of each hole is aligned with the center of the adjacent hole in the lateral direction. When aligned according to the first pattern, the edge-to-edge distance (EE) between the holes can be substantially equal in both the longitudinal and lateral directions. The first pattern does not involve offset holes.

[0064] Figure 4B This is an illustration of a portion of an open-cell layer comprising multiple holes arranged according to a second pattern different from a first pattern. The second pattern is a pattern of staggered holes. Staggered or diagonal arrangements are generally considered more dynamic and aesthetically pleasing than simple grid patterns and appear to promote breathability and perceived performance.

[0065] The hole can have any of the following shapes: circular, elliptical, hourglass-shaped, polygonal, and combinations thereof. Polygonal shapes include, but are not limited to, triangles, quadrilaterals, hexagons, octagons, or trapezoids. On the one hand, the hole is circular. On the other hand, the hole has an elliptical shape.

[0066] The pores in the open layer are approximately 0.4 mm. 2 approximately 25mm 2 or about 0.5mm 2 approximately 15mm 2 or 1mm 2 approximately 10mm 2 The opening area. A specific range was carefully selected to provide a balance between visual perception, comfort, and fluid handling perception. It is believed that an opening area of ​​less than 0.4 mm... 2 The openings may not be sufficiently visible to provide acceptable breathability and fluid handling perception. Furthermore, when dealing with more viscous fluids, an opening area of ​​less than 0.4 mm² is unsuitable. 2 The size of the orifice may be considered detrimental to fluid handling performance, as consumers may perceive it as insufficiently large to allow for rapid and efficient fluid reception. Furthermore, it is believed that orifices larger than 25 mm... 2The opening area can be considered as easily causing backflow and giving consumers a negative perception.

[0067] The perforated layer comprises multiple holes, each spaced apart by a defined edge-to-edge distance. The edge-to-edge distance is measured according to the hole measurement method described herein and corresponds to the shortest distance between the edge of one hole and the edge of an adjacent hole. In other words, the edge-to-edge distance is the minimum distance between two adjacent holes. To ensure material stability, regardless of their specific shape and width, the minimum edge-to-edge distance between most holes is at least 1 mm, or at least 1.5 mm, or 2.0 mm. Adjacent holes are spaced apart by edge-to-edge distances of about 1 mm to about 7 mm, or about 2 mm to about 5 mm, or about 4 mm to about 6 mm.

[0068] Without being bound by any theory, an edge-to-edge distance of less than approximately 1 mm can convey the impression that an absorbent material is not high-end or breathable, and may even trigger trypophobia. Furthermore, it is believed that when the edge-to-edge distance is greater than 7 mm, the pores are too sparse, thus negatively impacting the perception of breathability and being perceived as less effective in handling fluids.

[0069] Multiple holes can also vary in width. The holes in the perforated layer can have an aspect ratio of about 1 to about 3, or about 1.5 to about 2. This range of aspect ratios ensures that the holes have a visually pleasing shape, which contributes to the wearer's expected overall aesthetics and performance perception.

[0070] The open-cell layer may comprise approximately 6% to approximately 20% of the total open area, or approximately 7% to approximately 15%. Without being bound by any theory, approximately 6% to approximately 20% of the total open area provides a balanced distribution of pores, thereby positively contributing to breathability and perceived performance. It is believed that a total open area of ​​less than 6% is insufficient to provide significant breathability and perceived fluid handling. When the total open area is greater than 20%, consumers may perceive absorbent articles as inefficient in terms of breathability, softness, and fluid handling performance.

[0071] On the one hand, the perforated layer may have a total open area of ​​no more than about 20%, or no more than 25%, or no more than 30% for the purpose of mitigating or preventing backflow.

[0072] Multiple pores may have a depth of approximately 0.8 mm to approximately 3 mm, or 0.9 mm to approximately 1.5 mm, or 1 mm to 1.2 mm. This depth adds a three-dimensional texture to the open-cell layer, thereby further enhancing the perceived breathability and performance. The depth of each pore may be similar to or the same as the thickness of the open-cell layer.

[0073] On one hand, the perforated layer includes multiple pores across the entire layer; that is, multiple pores are distributed over the entire area of ​​the perforated layer. In other words, the perforated layer defines multiple pores across the entire layer such that the entire surface of the perforated layer includes pores, which are preferably uniformly distributed. This configuration ensures a consistent visual pattern across the entire surface of the perforated layer.

[0074] refer to Figure 5 The perforated layer may have a width and / or length smaller than that of the absorber core. The length extends along the longitudinal axis and corresponds to the length dimension of the core or the perforated layer. The width extends along the lateral axis, and the length and width are perpendicular. The length and width may intersect at point P, located at the midpoint of the length and the midpoint of the width. In one aspect, the perforated layer is in the form of a patch 50, which has substantially the same shape as the absorber core and includes, for example,... Figure 5 The intersection point P is indicated. Specifically, when the perforated layer is in the form of a patch, the perforated layer may cover at least 20%, at least 25%, or at least 30% of the entire area / surface of the absorber core, while including the intersection point P.

[0075] In one respect, the perforated layer can be an open-cell nonwoven layer. In another respect, the perforated layer can be a fluid management layer and can have a first surface in contact with the top sheet and a second surface in contact with the absorbent core.

[0076] Absorption core

[0077] The absorbent core of an absorbent product is used to store bodily fluids excreted during use. The absorbent core can be positioned between the top sheet and the bottom sheet.

[0078] Absorbent cores can be manufactured in a variety of sizes and shapes and can be molded to have different thicknesses, hydrophilicity gradients, superabsorbency gradients, densities, or mean basis weights at different locations across the entire surface of the product. In addition to conventional absorbent materials such as crepe cellulose fillers, fluffy cellulose fibers, wood pulp fibers also known as breathable felts, and textile fibers, cores often include superabsorbent materials that absorb fluids and form hydrogels. These materials are typically capable of absorbing large amounts of bodily fluids and retaining them under moderate pressure. Absorbent cores may include superabsorbent materials dispersed in a suitable carrier, such as cellulose fibers in the form of fluff or hardened fibers. Absorbent cores may include superabsorbent materials and do not contain free cellulose fibers in the form of fluff or hardened fibers. The term “superabsorbent polymer” as used herein refers to absorbent materials that may be cross-linked polymers and, when measured using a centrifugal retention capacity (CRC) test (EDANA method WSP 241.2-05E), are typically capable of absorbing at least 10 times their own weight in a 0.9% saline solution. SAP can specifically have a CRC value of more than 20 g / g, or more than 24 g / g, or 20 g / g to 50 g / g, or 20 g / g to 40 g / g, or 24 g / g to 30 g / g. SAP is usually in particulate form (superabsorbent polymer particles), but other forms of SAP, such as superabsorbent polymer foam, are not excluded.

[0079] negative

[0080] The backing sheet covering the underside of the absorbent core prevents fluid from the absorbent core from wetting contact with sanitary napkin products, such as underwear. Therefore, the backing sheet can be made of a liquid-impermeable film or a liquid-impermeable but vapor-permeable film / nonwoven composite, a microporous membrane, an open-cell molded membrane, or other vapor-permeable or vapor-permeable but substantially fluid-impermeable polymer membrane.

[0081] Film materials that are impermeable to any conventional liquid, typically used for absorbent materials, can be used as film. In some cases, foul odors emanating from the absorbed bodily excrement cannot pass through the film, preventing the odor from escaping. The film may or may not be breathable.

[0082] Absorbent articles with flanks

[0083] The film can extend over the entire absorbent structure and can be extended to form flanks, side-wrapping elements, or protective wings. Flanks or wings are disclosed in the literature and are available on the market.

[0084] Generally, the side wings extend laterally from the center of the absorbent product and are designed to fold around the edge of the wearer's panties in the crotch area. Therefore, the side wings are positioned between the edge of the wearer's panties and the wearer's thighs in the crotch area. Typically, the side wings are provided with attachment members for attaching the side wings to the underside of the wearer's panties. In most cases, the attachment device is similar to or equivalent to the panty fastening components of the underlayer, such as the adhesive layer. The wings serve at least two purposes: they prevent discharge from soiling the edge of the wearer's panties, and they help stabilize the absorbent product (such as a sanitary napkin) to prevent it from shifting, especially when the wings are attached to the underside of the panties.

[0085] Test methods

[0086] Sample preparation method

[0087] Measurements are performed on test samples taken from rolls or sheets of raw material or from material layers removed from absorbent articles. When separating the material layer from the absorbent article, care is taken to avoid contaminating or deforming the layer during the process. The removed layer should be free of residual adhesive. To ensure complete removal of adhesive, the layer is immersed in a suitable solvent that will dissolve the adhesive without adversely affecting the material itself. One such solvent is THF (tetrahydrofuran, CAS 109-99-9, for general purposes, available from any readily available source). After solvent immersion, the material layer is allowed to air dry thoroughly in a manner that prevents excessive stretching or other deformation of the material. After the material has dried, test specimens are obtained. The specimens must be as large as possible to account for any inherent material variability.

[0088] Opacity measurement methods

[0089] Opacity is a measure of a material's ability to obscure the background behind it. Opacity measurements are sensitive to material thickness and pigmentation (e.g., TiO2%).

[0090] a. Sample preparation

[0091] 1) Prepare the sample as described in the sample preparation method of this article, with the following modifications:

[0092] Generally speaking, a 7.5cm × 7.5cm portion of the sample is cut out from a stack of several layers of samples for analysis.

[0093] Most samples can be easily cut using a cutting die, i.e., a hydraulic cutter (such as an Alfa cutter). Scissors or a paper cutter can also be used; however, care must be taken not to damage other products required for analysis.

[0094] 2) Select samples without wrinkles, creases, tears, or other obvious defects / deformations for testing.

[0095] 3) Always stack and fold samples in the following manner: when converting for processing, the outer surface of the product will be the top surface of the sample directly below the instrument sample port, unless otherwise indicated in the instructions for a particular material.

[0096] 4) If sheet orientation exists, the samples are made such that all samples have the same MD.

[0097] 5) Select a portion of the sample for analysis. Using a suitable cutting device, cut a single 1-layer sample, 7.5 cm long, from each sample to be tested. 7.5cm, wherein the machine orientation is perpendicular and / or parallel to the cutting edge.

[0098] b. Equipment preparation

[0099] 1) Before starting any test, calibrate the spectrophotometer using the standard black and white plates provided with the instrument, according to the manufacturer’s instructions or SOP.

[0100] 2) Set the color scale to XYZ, the observation instrument to 10°, and the luminescent body to D65.

[0101] c. Test Procedure

[0102] 1) Place the white standard plate and the sample together in the spectrophotometer according to the manufacturer's instructions.

[0103] 2) Place the sample on top of the white standard plate without contaminating the test area, aligning it so that the machine orientation is parallel to the line separating the standard plate from left to right. The sample should also be positioned so that the polymer faces the light source.

[0104] 3) Record “Y”, accurate to 0.1 units.

[0105] 4) Repeat steps 2) to 3) above using a black standard plate instead of a white standard plate.

[0106] d. Calculation report

[0107] Opacity % = ["Y" (black panel) / "Y" (white panel)] × 100

[0108] It also reports the opacity (%), accurate to 0.1 units.

[0109] Thickness measurement methods

[0110] The thickness of the test specimen (prepared based on the sample preparation method described herein) is measured as the distance between the reference platform on which the specimen is placed and the pressure foot on which a specified amount of pressure is applied to the specimen for a specified period of time. All measurements are performed in a laboratory maintained at 23°C ± 2°C and 50% ± 2% relative humidity, and the specimen is conditioned in this environment for at least 2 hours prior to testing.

[0111] Thickness was measured using a manually operated micrometer equipped with a pressure foot capable of applying a stable pressure of 0.50 kPa ± 0.01 kPa to the specimen. This manually operated micrometer was a statically heavy instrument with readings accurate to 0.01 mm. A suitable instrument was the Mitutoyo Series 543 ID-C Digimatic, or equivalent, purchased from VWR International. The pressure foot was a flat, circular, movable surface with a diameter smaller than the test specimen, capable of applying the required pressure. A suitable pressure foot had a diameter of 25.4 mm, but smaller or larger pressure feet could be used depending on the size of the specimen being measured. The test specimen was supported by a horizontal, flat reference platform, which was larger than and parallel to the surface of the pressure foot. The system was calibrated and operated according to the manufacturer's instructions.

[0112] If necessary, the sample is obtained by removing it from the absorbent article. When removing the sample from the absorbent article, care should be taken not to cause any contamination or deformation to the sample layer during the process. The sample should be taken from an area without creases or wrinkles and must be larger than the pressure foot.

[0113] To measure thickness, first zero the micrometer relative to a horizontal, flat reference platform. Place the test specimen on the platform, with the test position centered below the pressure foot. Gently lower the pressure foot at a rate of 3.0 mm ± 1.0 mm per second until full pressure is applied to the test specimen. Wait 5 seconds, then record the specimen thickness to an accuracy of 0.001 mm. Repeat this process for a total of ten test specimens. Calculate the arithmetic mean of all thickness measurements and report the thickness to an accuracy of 0.001 mm.

[0114] Hole measurement method

[0115] 1. Image Acquisition :

[0116] A top-view image of the absorbent article is captured using an imaging chamber. If the absorber is a trouser-type absorbent article, the elastic band is cut along the side waist. The sample is preconditioned for at least 4 hours at ambient temperature and relative humidity (approximately 23°C and 50% RH, respectively) before measurement. The sample is then positioned in a flat configuration with the skin-facing surface upwards and secured to a metal frame at the front and rear ends using a pair of clamps. The metal frame is placed on top of a white diffused backlight sourced from Smart Vision Lights with an effective area of ​​600mm × 600mm and an average intensity rating of 30,000 lux. The backlight intensity is controllable via an adjustable output signal from 0 to 10 VDC. The sample is suspended approximately 75mm above the backlight, with no obstructions between the sample and the light. The backlight intensity is adjusted to achieve optimal contrast between porous and non-porous areas in the sample for further image processing. If the contrast from imaging the article is insufficient, the porous layer is removed from the article using the same sample mounting method and lighting conditions as described above for direct image acquisition. To remove the open-cell layer from the finished product, use a razor blade to cut a 50mm x 50mm sample from the underlying layer of the article around the outer perimeter; otherwise, cut the largest square possible from the material. If necessary, the open-cell layer can be removed from the article using a low-temperature spray (such as Cyto-Freeze, Control Company, Houston TX) or by immersion in a suitable solvent such as THF (tetrahydrofuran, CAS 109-99-9, for general purposes, available from any convenient source).

[0117] The chamber was equipped with a suitable camera system (such as a Canon EOS 6D Mark II with a 24-105mm focusing lens) and surrounded by a black curtain to minimize the effects of ambient lighting. The camera was mounted approximately 800mm above the sample, with the lens vertically aligned to capture top-view images. EOS utility software was used to connect to the Canon camera for remote image capture. Camera settings were configured with a 105mm focal length and balanced exposure achieved through appropriate selection of shutter speed, aperture, and ISO parameters (e.g., 1 / 250s, F8.0, and ISO100). Images of the sample were acquired under backlighting conditions after autofocus and white balance, and saved as TIF images with a resolution of 6240×4160 pixels.

[0118] 2. Image Analysis

[0119] The analysis was performed using an image analysis program such as ImageJ software (version 1.52p or later, National Institutes of Health, USA) or an equivalent. The TIF image was compressed without compromising image quality, and the distance was then calibrated to give an image resolution of 17.8 pixels / mm.

[0120] 2.1 Hole opening area and hole length-to-width ratio

[0121] Open the sample image in ImageJ and rotate it to ensure the article's longitudinal orientation is horizontal. Set the image scale according to the image resolution. Crop the region of interest to include exactly ten pores from the openwork layer surrounding the center of the absorbent article.

[0122] Convert the RGB image to 8 bits: The cropped image is converted to 8 bits, and due to the backlight, the hole appears brighter than the background. If the image background is uneven, a "rolling ball" algorithm is used to subtract the background. This method is described in Sternberg Stanley's article "Biomedical Image Processing," IEEE Computer, Vol. 16, No. 1, January 1983. An appropriate rolling ball radius is set, such as 200 pixels, to ensure it is at least as large as the radius of the largest object in the 8-bit image that is not part of the background.

[0123] Converting an 8-bit image to binary: An 8-bit grayscale image is converted to a binary image with "white" foreground pixels corresponding to the aperture using a "minimum" thresholding method. This is done by using a histogram of grayscale (GL) values ​​(ranging from 0 to 255, with each grayscale level i having a tendency P). i If a bin has exactly two local maxima, then the threshold gray level value t is defined as P in the case of that value. t-1 >P t And P t ≤P t+1 If the histogram has more than two local maxima, iteratively smooth the histogram using a windowed arithmetic mean of size 3 until exactly two local maxima exist. The grayscale threshold t is then defined as P at that value. t-1 >P t And P t ≤P t+1This procedure identifies the minimum group of grayscale values ​​(GL) located between the dark pixel peaks in the non-aperture region and the brighter pixel peaks in the aperture region. If the histogram contains zero or one local maximum, the method cannot proceed further, and an alternative method is applied to image segmentation: k-means clustering is applied to pixel-based segmentation, assigning each pixel in the input image to one of the clusters. The k-means clustering method is configured with the following parameters: number of clusters is 4; cluster center tolerance is 0.0001; randomization seed is enabled (randomization seed: 48); and clusters are displayed as centroid values. The output image where the clusters are represented by centroid values ​​is selected and converted to binary by setting a threshold corresponding to the “white” foreground pixels of the aperture.

[0124] A dilation operation is performed on the binary image, followed by an erosion operation, where an adjacent foreground pixel is set for both dilation and erosion. Measurements are set up to include analysis of the aperture opening area and shape descriptor, specifically the aspect ratio, which is the ratio between the major and minor axes of the fitted ellipse. This involves replacing the selected region with the best-fit ellipse while maintaining the same area, orientation, and centroid as the original selection. The area and aspect ratio values ​​for ten apertures are obtained. The apertures are filled by outlining their contours along their outer edges, and apertures smaller than 0.40 mm are excluded. 2 Any holes, or those with incomplete openings at the edges of the acquired image, are considered. The top ten area values ​​corresponding to the ten holes are analyzed to calculate the average hole size, accurate to 0.01 mm. 2 Perform this analysis on three replicate samples and report the arithmetic mean as the well opening area. Similarly, analyze the aspect ratios of ten wells to calculate the average aspect ratio, accurate to 0.01. Analyze three replicate samples and report the arithmetic mean as the well aspect ratio.

[0125] 2.2 Percentage of total opening area and edge-to-edge distance

[0126] Open the sample image in ImageJ and rotate it to ensure the article's longitudinal direction is horizontal. Set the image scale according to the image resolution. Select a 35mm × 35mm region of interest around the center of the absorbed article to ensure the opening layer is present across the entire selection. Convert the cropped RGB image to 8 bits and then to a binary image, referring to the procedure described in section 2.1 above.

[0127] Perform dilation on the binary image using settings for both dilation and erosion on an adjacent foreground pixel. Set the measurement to include the analysis of the aperture opening area and obtain the area values ​​of the apertures within the region of interest. Ensure that the apertures are filled, outlining them along their outer edges, and exclude any apertures smaller than 0.40 mm². Sum the area values ​​of all selected apertures, divide by the area of ​​the region of interest, and multiply by 100 to calculate the aperture percentage, accurate to 0.01%. Analyze three replicate samples and report the arithmetic mean as the total aperture area.

[0128] The edge-to-edge distance between holes can be measured by further analysis of the binary image, which is analyzed for the percentage of the total opening area of ​​the holes. First, a dilation operation is performed on the binary image using settings for both dilation and erosion on an adjacent foreground pixel, followed by an erosion operation. Outliers are removed using a median filter; if a pixel is brighter than its surroundings, the median filter replaces that pixel with the median of the surrounding area with a radius of 5 pixels, and then the holes in the holes are filled. Next, a Voronoi operation is performed. This generates an image of cells defined by pixel lines having equal distances to the two nearest patterned holes, where the pixel values ​​are output from the Euclidean distance map (EDM) of the binary image. An EDM is generated when each pixel between holes in the binary image is replaced with a value equal to the pixel distance to the nearest patterned hole. Then, background zeros are removed to enable statistical analysis of the distance values. This is achieved by using an image calculator to divide the Voronoi cell image itself to produce a 32-bit floating-point image, where all cell lines have a value of one, and the rest of the image is identified as Not-a-N (NaN). Finally, using an image calculator, the image is multiplied by the initial Voronoi cell image to produce a 32-bit floating-point image, where distance values ​​along the cell lines are preserved and all zero values ​​are replaced with NaN. The pixel distance values ​​are converted to actual edge-to-edge distances by multiplying the values ​​in the image by the image's pixel resolution (approximately 0.056 mm / pixel), and then multiplying the image again by 2, as this value represents the midpoint distance between holes. The modulus of the edge-to-edge distances in the image is measured and recorded, accurate to 0.1 mm. This procedure is run for all three replicate images. The average value is then reported as the edge-to-edge distance.

[0129] Consumer testing for performance index and perceived breathability assessment

[0130] To understand consumer perceptions of different perforation patterns on sanitary napkins (“samples”), a panel of 60 female participants (aged 18 to 40) was recruited. Samples 1 to 4, as described in the Embodiments section of this application, were presented to a first group of 30 participants. Samples 5 to 11, as described in the Embodiments section of this application, were presented to a different second group of 30 participants. Participants were asked to handle and visually inspect the samples. Samples were presented to the participants individually.

[0131] The panel members were also asked to rate the perceived air permeability of the samples on a scale from 0 (very poor) to 10 (excellent) (a score of "0" means extremely poor air permeability, a score of "6" means acceptable, and a score of "10" means extremely breathable). To assess the perceived performance of the samples, a performance index was used that combined air permeability with other relevant performance indicators, such as perceptions of how the sample would handle flow and perceptions of softness. The samples were rated on a scale from 0 (very poor) to 10 (excellent), with 6 being acceptable. The performance index was then calculated as follows: Performance Index = Air Permeability Score multiplied by Flow Handling Score multiplied by Softness Score.

[0132] Example

[0133] Example 1 – Sample Preparation

[0134] Samples of absorbent products in the form of sanitary napkins were prepared. All samples included a top sheet, an absorbent core, and an open-cell layer disposed between the top sheet and the core. Samples were prepared using standard methods for sanitary napkins.

[0135] Top sheets were prepared using a conventional hot air permeation process.

[0136] - The first top film (TS1) has 22g / m 2 The base weight is achieved by using 2 denier bicomponent fiber PE / PET outer sheath / core.

[0137] - The second top film (TS2) has 24g / m 2 The base weight is composed of a 4 denier bicomponent fiber PE / PET outer sheath / core.

[0138] - The third top layer (TS3) has 27g / m 2 The base weight is made of 1.5 denier bicomponent fiber PE / PET outer sheath / core and 3 denier bicomponent fiber PE / PP outer sheath / core.

[0139] - The fourth top film (TS4) has 45g / m 2 The base weight is made of 2.5 denier bicomponent fiber PE / PET outer sheath / core.

[0140] The open-cell layer, such as, for example, the collection layer, is prepared using a conventional combing process and comprises 1.5 denier viscose; 1.35 denier PET; or 5.9 denier PET. The open-cell layer includes pores having a substantially circular (or annular) shape, which are formed by conventional processes such as needle roller opening, water jet punching, or over-bonding and ring rolling.

[0141] - The first open layer (AL1) has a base weight of 100 gsm.

[0142] - The second open layer (AL2) has a base weight of 35 gsm.

[0143] - The third open layer (AL3) has a base weight of 80 gsm.

[0144] The absorbent core is prepared using the hydrogen-bonded airflow web forming (HBAL) process and comprises pulp, latex AGM, and 2 denier bicomponent fiber PE / PET outer sheath / core.

[0145] Different combinations of top sheet, open-cell layer, and core were prepared and are presented in Tables 1a, 1b, 1c, 2, and 3. The samples presented in each table differ only in the features described in the table. In other words, if a sample contains a distinguishing element, that element will be described in the table.

[0146] Example 2

[0147] Prepare samples 1 to 11 and then present them to the group.

[0148] Samples 1 through 4 have different levels of opacity, as measured by opacity measurement methods.

[0149] Samples 5 to 9 are menstrual pads with different pore opening areas, which were measured according to the pore measurement method disclosed herein.

[0150] Samples 6, 10, and 11 show different edge-to-edge distances.

[0151] Evaluate and rate the impact of the combination of top sheet opacity and individual hole opening area, edge-to-edge distance, and / or total opening area on the performance index and perceived breathability.

[0152] Table 1a below summarizes the scores of the members of the first group.

[0153] Tables 1b and 1c below summarize the ratings from the second group of group members.

[0154] Table 1a

[0155]

[0156] Table 1b

[0157]

[0158] Table 1c

[0159]

[0160] Samples 1 and 2 are estimated to provide an overall impression of better breathability and performance index than samples 3 and 4.

[0161] In other words, samples 3 to 4 had lower average scores in perceived breathability and performance index than samples 1 and 2.

[0162] Similarly, samples 5 through 7 were estimated to provide a greater overall perceived breathability and performance index than samples 8 through 9. Those samples appeared to achieve improved perceived breathability and a higher performance index.

[0163] Furthermore, samples 6 and 10 were rated better than sample 11, which was not within the scope of this invention.

[0164] Example 3 - Hole Depth

[0165] Samples 13 to 15 with different pore depths were prepared and then exposed to the panel members. The measured pore depths corresponded to the thickness of the open-pore layer positioned between the top sheet and the absorber core. The rating results are indicated in Table 2 below.

[0166] Table 2

[0167]

[0168] Compared to sample 14, which does not fall within the scope of this invention, samples 13 and 15, in which the pore depth is at least 0.8 mm, were evaluated to provide improved air permeability and performance index.

[0169] Example 4 - Coverage

[0170] Sample 1 comprises an open-cell layer in the form of a patch. The patch does not completely cover the surface of the absorber core and occupies approximately 30% of the absorber core. The patch has a shape substantially similar to that of the core and has a surface area occupying approximately 30% of the core's surface. Furthermore, the patch is configured such that the center of the patch coincides with the center of the core.

[0171] Sample 13 includes an open-cell layer whose dimensions along the longitudinal and lateral directions are substantially equal to the core dimensions. In this configuration, the open-cell layer can cover approximately 100% of the core surface (i.e., a fully covered configuration), for example, as shown below. Figure 1exemplified.

[0172] Samples 1 and 13 were evaluated by the panel members, and the results are shown in Table 3 below.

[0173] Table 3

[0174]

[0175] Compared to Sample 1, Sample 13 is generally more favored by consumers in terms of breathability and performance index.

[0176] Absorbent products with open-cell structures that have a full coverage configuration showed higher scores in terms of performance index and perceived breathability than open-cell structures in patch form.

[0177] The dimensions and values ​​disclosed herein should not be construed as strictly limited to the precise numerical values ​​cited. Rather, unless otherwise specified, each such dimension is intended to represent the stated value and the range surrounding its functional equivalent. For example, a dimension disclosed as “40 mm” is intended to represent “approximately 40 mm”.

[0178] Unless expressly excluded or otherwise limited, every reference cited herein, including any cross-references or related patents or patent applications, and any patent application or patent claiming priority to or benefiting from it, is incorporated herein by reference in its entirety. Reference to any reference is not an endorsement of it as prior art to any disclosed or protected art herein, nor is it an endorsement of any such invention, either on its own or in combination with any one or more references. Furthermore, where any meaning or definition of a term in this invention conflicts with any meaning or definition of the same term in referenced documents, the meaning or definition given to that term in this invention shall prevail.

[0179] While embodiments of the invention have been illustrated and described by way of example, it will be apparent to those skilled in the art that many other changes and modifications can be made without departing from the spirit and scope of the invention. Therefore, it is intended that all such changes and modifications falling within the scope of the invention be covered by the appended claims.

Claims

1. An absorbent article, the absorbent article comprising a top sheet, a bottom sheet, an absorbent core positioned between the top sheet and the bottom sheet, and The perforated layer is positioned between the top sheet and the absorbent core. The top sheet described herein has an opacity of approximately 15% to approximately 40%, as determined by an opacity measurement method. The perforated layer comprises a plurality of holes, each having a diameter of approximately 0.4 mm as determined by a hole measurement method. 2 approximately 25mm 2 or about 0.5mm 2 approximately 15mm 2 or 1mm 2 approximately 10mm 2 The opening area, The adjacent holes are spaced apart by an edge-to-edge distance of approximately 1 mm to approximately 7 mm, or approximately 2 mm to approximately 5 mm, or approximately 4 mm to approximately 6 mm, as determined by the hole measurement method.

2. The absorbent article of claim 1, wherein the open-cell layer comprises about 6% to about 20% of the total open area.

3. The absorbent article according to claim 1 or 2, wherein each pore has a depth of about 0.8 mm to about 3 mm or 0.9 mm to about 1.5 mm.

4. The absorbent article according to any one of the preceding claims, wherein each pore comprises an aspect ratio of about 1 to about 3, or about 1.5 to about 2.

5. The absorbent article according to any one of the preceding claims, wherein the article includes a longitudinal axis and a lateral axis perpendicular to the longitudinal axis, wherein the longitudinal axis and the lateral axis intersect at an intersection point P, wherein the perforated layer includes the intersection point and covers at least 30% of the total surface area of ​​the absorbent core.

6. The absorbent article according to any one of the preceding claims, wherein the plurality of holes have a shape selected from circles, ellipses, triangles, squares, rectangles, parallelograms, trapezoids, polygons, hourglasses, and stars.

7. The absorbent article according to any one of the preceding claims, wherein the open-cell layer is an open-cell nonwoven layer.

8. The absorbent article according to any one of the preceding claims, wherein the open-cell layer is a fluid management layer.

9. The absorbent article according to any one of the preceding claims, wherein the absorbent article is selected from sanitary napkins or trousers.

Images