Female panty liner with foam absorbent layer composition and improved body conformity

Abstract

A female panty liner includes a liquid permeable topsheet, a liquid impermeable backsheet, and an absorbent layer disposed between the topsheet and the backsheet. The absorbent layer includes an open cell foam layer including an arrangement of large voids therein. The arrangement of large voids defines a path placed along the x-y plane surface of the open cell foam layer and includes left and right forward path legs disposed primarily forward of the lateral axis.

Description

Technical Field

[0001] This disclosure relates in general to feminine sanitary pads having a foam absorbent layer component, and particularly to feminine sanitary pads having a foam absorbent layer with a large pore arrangement. Background Technology

[0002] Currently, feminine panty liners are manufactured and marketed that include an absorbent component formed from elastic open-cell polymer foam. The inclusion of elastic open-cell foam is considered desirable in some consumer / user segments because it imparts a soft, supple, and comfortable feel to the panty liner, and in some examples, relatively thin (i.e., with a relatively low thickness) panty liners are offered, which is desirable because thin and supple panty liners are relatively inconspicuous when worn under clothing compared to panty liners that rely on cellulose fiber material components for absorption.

[0003] For feminine sanitary pads, a close fit to the wearer's body is considered important for at least three purposes: minimizing the chances of menstrual fluids migrating along the skin surface and escaping capture and absorption by the pad (and thus staining underwear, outerwear, bedding, etc.); maximizing the efficient use of the absorbent components and the pad's functionality; and inconspicuousness under clothing. However, due to the elasticity of typical open-cell polymer foam, pads made with such foam layer components may resist flexing and wrinkling to some extent and may have shape memory, causing them to bias toward their original configuration (typically, roughly flat / planar). Therefore, they may, to some extent, hinder maintaining a close fit to the complex, irregularly curved, and intersecting shape features of the human female body in the crotch area. Absorbent products with more structured constructions (e.g., 3D shape features that provide a closer fit) such as interlabial pads or inserts may be a cause or source of discomfort.

[0004] Therefore, manufacturers that can provide comfortable, soft feminine sanitary pads with improved body conformation have a competitive advantage in the market compared to currently available products. Summary of the Invention

[0005] This disclosure addresses the issue of body conformation in feminine sanitary pads by providing an absorbent layer with a large pore arrangement that improves the pad's ability to conform closely to the wearer's body in the crotch area while maintaining wearer comfort.

[0006] This document describes a feminine sanitary pad comprising a front end, a rear end, and a longitudinal axis and a lateral axis intersecting at a point; a liquid-permeable top sheet; a liquid-impermeable bottom sheet; and an absorbent layer disposed between the top sheet and the bottom sheet. The absorbent layer includes an open-cell foam layer having a thickness in the z-direction and an outer periphery along the xy-plane. The open-cell foam layer includes an arrangement of large voids having a depth in the z-direction. The arrangement of large gaps defines a path that is placed along the xy-plane surface of the open-cell foam layer and includes a left forward path leg, which is mainly located in front of the lateral axis and begins at a left center position near the intersection of the axes, and ends at a left outer position located in front of the first left center position and further outward of the longitudinal axis than the first left center position; and a right forward path leg, which is mainly located in front of the lateral axis and begins at a right center position near the intersection of the axes, and ends at a right outer position located in front of the first right center position and further outward of the longitudinal axis than the first right center position.

[0007] This article also describes a feminine sanitary pad comprising a front end, a rear end, and a longitudinal axis and a lateral axis intersecting at a point; a liquid-permeable top sheet; a liquid-impermeable bottom sheet; and an absorbent layer disposed between the top sheet and the bottom sheet. The absorbent layer comprises an open-cell foam layer having a thickness in the z-direction and an outer periphery along the xy-plane. The open-cell foam layer includes an arrangement of large voids having a depth in the z-direction. The arrangement of the large voids defines a path placed along the xy-plane surface of the open-cell foam layer and includes a left forward path leg, which is primarily positioned in front of the lateral axis and begins at a left center position near the intersection of the axes, and ends at a left outer position positioned in front of a first left center position and further outward of the longitudinal axis than the first left center position; and a right forward path leg, which is primarily positioned in front of the lateral axis and begins at a right center position near the intersection of the axes, and ends at a right outer position in front of a first right center position and further outward of the longitudinal axis than the first right center position. At least one of the left and right forward path legs has a ratio of large void length to gap length of approximately 30:1 to approximately 1:5. Attached Figure Description

[0008] Figure 1 This is a plan view of an example of a feminine sanitary pad, with the top panel facing the observer.

[0009] Figure 2 This is a plan view of an example of an absorption layer.

[0010] Figure 3A yes Figure 1 A schematic lateral cross-section of a feminine sanitary pad.

[0011] Figure 3B yes Figure 3A The enlarged portion 3B of the attached figure is magnified to show the sublayer of the absorption layer, which may exist in some examples.

[0012] Figure 4A This is a plan view of an example of an absorption layer, showing an example of an arrangement with large voids.

[0013] Figure 4B and Figure 4C yes Figure 4A The diagram shown illustrates the planar view of the absorption layer, illustrating the path of the large voids.

[0014] Figure 4D yes Figure 4A The diagram shown illustrates a plan view of the absorption layer, illustrating the region that bends or shifts in the z-direction around the large void path.

[0015] Figure 4E and 4F It is along Figure 4D The lateral cross-sections shown by lines 4E-4E and 4F-4F represent the configuration in which the absorbent layer will be present when the pad, including the absorbent layer, is worn by the wearer / user.

[0016] Figure 4G This is a plan view of an example of an absorption layer, which combines an example of an arrangement of large voids with an example of an arrangement of perforations.

[0017] Figure 4H This is a plan view of another example of an absorption layer, which combines an example of an arrangement of large voids with an example of an arrangement of perforations.

[0018] Figure 4I This is a plan view of an example of an absorption layer, showing an arrangement with large voids and added reinforcements.

[0019] Figure 5 This is an example of an arrangement of large gaps that define the forward path, as described in this article.

[0020] Figure 6 This is an example of a large gap arrangement that does not restrict the forward path, as described in this article.

[0021] Figure 7 This is an example of a large gap arrangement that does not restrict the forward path, as described in this article.

[0022] Figure 8 This is an example of an arrangement of large gaps that define the forward path, as described in this article.

[0023] Figure 9 This is an example of a large gap arrangement that does not restrict the forward path, as described in this article.

[0024] Figure 10 This is an example of an arrangement of large gaps that define the backward path, as described in this article.

[0025] Figure 11A and Figure 11B This is a schematic cross-sectional illustration of a portion of the pad, in which the absorbent layer remains unwrinkled across the large pores at full depth. Figure 11A ) and wrinkles ( Figure 11B ).

[0026] Figure 12 A schematic cross-section of a portion of a pad having an absorbent layer with a partially deep void space is illustrated. Detailed Implementation

[0027] definition

[0028] Compared to a feminine sanitary pad that is opened and placed flat on a horizontal surface, "lateral" refers to a direction that is perpendicular to the longitudinal direction and parallel to the horizontal surface.

[0029] "Longitudinal" refers to the direction parallel to the line along which the measured length is taken and parallel to the horizontal plane, relative to a feminine sanitary pad that is opened and laid flat on a horizontal surface and has a length measured from the front end to the back end. "Length" refers to the dimension measured in the longitudinal direction.

[0030] In contrast to feminine sanitary pads, the terms "front," "back," "forward," and "rear" refer to the features or areas of the pad that correspond to the positions it would typically occupy when worn by the user, and the front / interior and back / rear of the user's body when standing.

[0031] In contrast to a feminine sanitary pad laid flat on a horizontal surface, or a nonwoven fabric lying flat on a horizontal surface, the "z-direction" refers to the direction perpendicular to the horizontal surface, and any plane parallel to the horizontal surface can be called the "xy-plane." When the pad is worn by a user (and thus compressed into a curved configuration), the "z-direction" at any given point on the pad refers to the direction approximately perpendicular to the wearer-facing surface of the pad at that point. In contrast to the nonwoven fabric during its manufacture, the "z-direction" refers to the direction orthogonal to both the manufacturing direction and the cross-manufacturing direction, and any plane parallel to both the manufacturing direction and the cross-manufacturing direction can be called the "xy-plane."

[0032] In relation to feminine sanitary pads, "wear-facing" is a relative positional term that refers to a component or structure of the pad that, when in use, is closer to the wearer than another component or structure positioned along the same z-direction. For example, the top sheet has a wear-facing surface that is closer to the wearer than the opposite, outward-facing surface of the top sheet.

[0033] In relation to feminine sanitary pads, "outward-facing" is a relative positional term that refers to a part of the pad's components or structure that, when in use, is further away from the wearer than another feature of the components or structure placed along the same z-direction. For example, the top sheet has an outward-facing surface that is further away from the wearer than the opposite, wearer-facing surface of the top sheet.

[0034] The relative positional terms "inner" and "outer" refer to the positioning of the first feature relative to the second feature relative to the lateral or longitudinal axis of its pad or layer component when two features are located on the same side of an axis. For example, when the first feature is closer to the longitudinal axis of the pad than the second feature, the first feature is laterally "inner" and the second feature is laterally "outer" of the first feature. Similarly, when the first feature is closer to the lateral axis of the pad than the second feature, the first feature is longitudinally "inner" and the second feature is longitudinally "outer" of the first feature.

[0035] "Large voids" in a foam layer are defined voids with dimensions in the xy plane and z direction, visible to the naked eye of an adult with normal vision at arm's length, and are created by: (a) removing material from the foam after foam formation via a manufacturing process; or (b) molding large voids into the finished foam by molding foam precursor material. Therefore, closed or open pores of random size and location appearing within a porous foam structure as a characteristic of the foam preparation process are not "large voids" for the purposes of this paper. Large voids may extend entirely through the z-direction thickness of the foam layer, or they may extend only partially through the z-direction thickness of the foam layer.

[0036] "Forward path of large voids" (or similar expression) refers to any identifiable imaginary straight or curved path along the xy plane of the surface of the absorber layer, having a start point and an end point at the distal edge of the large voids, wherein the start point and the end point are at least 2.5 cm apart, and along the path, at least 50%, preferably at least 67%, and more preferably at least 75% of its length traverses two or more large voids, and does not include discontinuities or directional changes of more than 30 degrees along the straight line dimension from the start point to the end point at a distance of 2.5 cm or less.

[0037] For example, Figure 5A straight forward path 50f (shown as a dashed line) conforming to the definition of the large gap 51 is depicted. Path 50f has a starting point on the far edge of the leftmost large gap in the figure and an ending point on the far edge of the rightmost large gap in the figure. The length of the path is pl1; and more than 40% of this length traverses the five large gaps 51 shown, such that (the sum of lengths a) / pl1 > 0.50.

[0038] Figure 6 The path 50x was drawn that does not conform to the definition because (the sum of lengths b) / pl2 < 0.50.

[0039] Figure 7 The path 50x was drawn that does not conform to the definition because (the sum of lengths c) / pl3 < 0.50.

[0040] exist Figure 8 In this context, it is assumed that the dimension pd of the straight path is greater than 2.5 cm, and the smaller angle α between the lines 52 tangent to the curve of the forward path 50f at each of its ends is no greater than 30 degrees. Figure 8 A curved forward path 50f conforming to this definition of a large gap 51 is depicted. The path, along a straight path of length greater than 2.5 cm, varies in direction by no more than 30 degrees in dimension pd. The sum of the lengths d of all the large gaps 51 traversed by the path, divided by the length of the curved forward path 50f, is greater than 0.50.

[0041] exist Figure 9 The example illustrates the identification and... Figure 7 An alternative attempt at conformal paths for similar large gaps is shown. When the proposed path 50x is drawn, the portion that crosses the large gaps 51, each with a maximum size e, is maximized, and the portion that does not cross the large gaps 51 is minimized. The sum of the maximum sizes e divided by the total path length is now greater than 0.50. However, assuming the shown straight path size pd is less than 2.5 cm, Figure 9 The proposed path 50x was drawn because its orientation changes by more than 30 degrees (and changes twice) within a dimension pd smaller than 2.5 cm. This non-compliant orientation change is repeated throughout the proposed path 50x. Therefore, even if redrawn, the proposed path 50x does not conform to the definition.

[0042] "The backward path of a large void" (or similar expression) refers to any identifiable imaginary straight or curved path along the xy plane of the surface of the absorber layer, having a start point and an end point at the distal edge of the large void, wherein the start point and the end point are at least 2.5 cm apart, and along the path, at least 30%, or at least 40%, or at least 60% of its length traverses two or more large voids, and does not include discontinuities or directional changes of more than 30 degrees along the straight line dimension from the start point to the end point 2.5 cm or less apart.

[0043] Figure 10 The path 50r is drawn that conforms to this definition because (the sum of lengths f) / pl4 > 0.30. For example... Figure 10 As shown, in some configurations, a portion of the backward path of the large void may intersect with one or more perforations 42r (as described herein).

[0044] describe

[0045] See Figure 1 , Figure 2 and Figure 3AThe feminine sanitary pad 10 may include a liquid-permeable top sheet 20, a liquid-impermeable bottom sheet 30, and an absorbent layer 40 disposed between the top sheet and the bottom sheet. The absorbent layer has an outer perimeter 41. In the area outside the outer perimeter 41, the top sheet and the bottom sheet may be laminated together by any suitable mechanism, including but not limited to adhesive bonding, thermal bonding, pressure bonding, etc., thereby encapsulating, holding, and securing the absorbent layer 40 in place between the top sheet 20 and the bottom sheet 30. As suggested in the figure, the absorbent layer 40 may be cut or otherwise given an asymmetrical shape about a lateral axis, with the aim of allowing the continuous absorbent layer 40 to be cut from the raw material along the nested contour, thereby providing efficient utilization of absorbent layer raw material / minimization of cut-off waste. It may be preferred that the laterally wider portion of this shape is located at the rear of the pad, with the aim of providing a larger surface area to intercept fluid moving along the skin through the buttock crease. The pad 10 may include opposing wings 15 that extend laterally outside the perimeter 41 with a relatively larger width dimension than the main portion of the pad. The outer surface of the underside of the pad forming the main body and wings may have a deposit of adhesive 35 thereon. The adhesive deposit 35 may be provided to allow the user to adhere the pad to the inside of her panties in the crotch area, and to pass the wings through and wrap around the inside edge of the panties' leg openings, adhering them to the outside / underside of the panties in the crotch area, thus providing additional retaining support and helping to protect the panties' leg edges from soiling. When the pad 10 is packaged, the adhesive deposit 35 may be covered by one or more release films or sheets (not shown) that cover / mask the adhesive deposit 35 to prevent it from contacting and / or becoming contaminated with other surfaces until the user is ready to remove the release film or sheet and place the pad for use.

[0046] Top film

[0047] The top sheet 20 can be formed of any suitable nonwoven fabric material that is compliant, soft to the touch, and non-irritating to the wearer's skin. Referring again to these figures, the top sheet 20 is positioned adjacent to the wearer-facing surface of the absorbent layer 40 and can be bonded thereto and to the bottom sheet 30 by any suitable attachment or adhesive method. The top sheet 20 and the bottom sheet 30 can be directly bonded to each other in the peripheral region outside the periphery 41 of the absorbent layer 40, and can also be indirectly bonded by directly bonding them to the wearer-facing and outward-facing surfaces of the absorbent layer, respectively, or by additional optional layers included in the pad.

[0048] A suitable topsheet material will include a liquid-permeable material that is comfortable in contact with the wearer's skin and allows draining fluids to pass through quickly. Suitable topsheets can be made from a variety of materials, such as nonwoven mesh materials.

[0049] Non-limiting examples of nonwoven fiber web materials suitable for use as top sheets include fiber materials made of natural fibers, modified natural fibers, synthetic fibers, or combinations thereof. Suitable examples are described in U.S. Patent Nos. 4,950,264, 4,988,344, 4,988,345, 3,978,185, 7,785,690, 7,838,099, 5,792,404, and 5,665,452.

[0050] In some examples, the topsheet may comprise clusters, as described in US 8,728,049, US 7,553,532, US 7,172,801, US 8,440,286, US 7,648,752, and US 7,410,683. The topsheet may have a pattern of discrete hair-like fibrils as described in US 7,655,176 or US 7,402,723. Additional examples of suitable topsheet materials include those described in US 8,614,365; US 8,704,036; US 6,025,535, and US 2015 / 041640. Another suitable topsheet may be formed from a three-dimensional substrate, as detailed in US 2017 / 0258647. The top sheet may have one or more layers, as described in US2016 / 0167334, US 2016 / 0166443 and US 2017 / 0258651.

[0051] As envisioned herein, the component nonwoven fiber web material from which the top sheet 20 can be cut may be a nonwoven fiber web material comprising or primarily composed of fibers spun from a polymer resin (by weight), such as polyolefins and / or polyesters, including but not limited to polypropylene, polyethylene and their variants, blends, and bicomponent or multicomponent arrangements.

[0052] Nonwoven fiber webs can be formed by any suitable method in which spun fibers of varying lengths are distributed and accumulated onto a moving forming belt in a controlled manner to form a wadding with the desired fiber distribution and basis weight. Suitable methods may include spunbonding and meltblowing. After accumulation, the wadding can be processed by any suitable method to consolidate and bond the fibers into a cohesive fiber web, including calendering, calendering thermal bonding, calendering compression bonding, and ventilated bonding. The consolidated fiber web can undergo further processes such as water strengthening or hydroentangling to increase the z-axis entanglement of the fibers and increase bulk.

[0053] In some configurations, nonwoven fiber web materials can be formed in a co-forming process in which finite-length hydrophilic fibers (such as plant-based fibers, e.g., cotton fibers, synthetic fibers, etc.) are physically blended or mixed with longer but indeterminate-length spun fiber streams, spun from a polymer resin, and placed on a forming belt to form a fiber web, as described in, for example, US 8,017,534; US 4,100,324; US 2003 / 0200991; US ​​5,508,102; US 2003 / 0211802; EP 0 333228; WO 2009 / 10938; US 2017 / 0000695; US 2017 / 0002486; US 9,944,047; 2017 / 0022643 and US 2018 / 0002848.

[0054] Without enhancing the materials and / or processes involved, generally speaking, monocomponent fibers spun from polymer resins tend to have relatively simple surface geometries (typically circular or nearly elliptical cross-sections) and substantially non-cuffed or non-crimped configurations along their length. Therefore, when spun fibers are deposited and accumulated on a forming belt, calendered, and bonded (e.g., in a spunbond process), the resulting nonwoven web product will have a relatively low bulk and a relatively flat appearance compared to a fiber web formed from fibers with a more complex shape (e.g., crimped or curled). Lower-bulk nonwoven webs can be perceived by some consumers as having a relatively unpleasant feel and appearance; that is, they can be perceived as relatively less soft or luxurious than higher-bulk nonwoven webs.

[0055] To increase the bulk of the fiber web without increasing the basis weight (and material usage), and to increase the opacity of the fiber web, multi-component, such as bicomponent fiber configurations, fibers for preparing the fiber web can be spun. Resin processing equipment and spinneret housings can be constructed, and polymer resins can be selected to spin bicomponent fibers that curl or crimp as they exit the spinneret as a stream of molten polymer, and subsequently cool and solidify into fibers. Known processes and polymer resin selections can be used to prepare crimped spun bicomponent fibers having side-by-side, eccentric core-shell, or other non-coaxial polymer component cross-sectional configurations. In such non-coaxial configurations, one of the polymer components can be selected and / or formulated to have a different melt temperature and / or cooling shrinkage rate than the other polymer component. Upon cooling, the different properties of the polymer components and the non-coaxial cross-sectional arrangement of the component portions of the molten fiber stream impart crimping to the fibers as they cool, shrink at different rates, and solidify. The corresponding polymer resin components can be different polymers, different forms or variants of the same polymer, or different blends thereof. More detailed disclosures of spinning crimped or coiled bicomponent fibers and their formation into nonwoven fiber webs can be found, for example, in US 8,501,646; US EP 1,988,793; and US 2007 / 0275622. In some examples, the bicomponent fibers may have respective resin components that are predominantly polypropylene-based, which are formulated to impart different melt temperatures to the respective components. In some examples, the bicomponent fibers may have respective components, one of which is predominantly polypropylene-based and the other is predominantly polyethylene-based. In some more specific examples, the bicomponent fibers may be spun in an eccentric core-sheath configuration, wherein the predominantly polypropylene-based component is the core component and the predominantly polyethylene-based component is the sheath component; wherein the polypropylene-based component may be desired due to its greater tensile strength, and the polyethylene-based component may be desired due to its smoother, more lubricated surface feel, which helps to impart a silky feel to the fiber and nonwoven fiber web material. It should be understood that different cooling shrinkage rates and other different qualities that affect the quality (including crimping or curling) and properties of spun fibers can be selected for different combinations of polyolefins and / or other spinnable thermoplastic resins.

[0056] The top sheet may also incorporate or include any features of the top sheet described in U.S. Patent Application Serial Nos. 16 / 789,516 and / or 16 / 789,522.

[0057] Many commercially viable thermoplastic resins that can be processed and spun into bicomponent fibers are typically hydrophobic. These resins include polyolefins such as polypropylene and polyethylene. Nonwoven web materials formed from such fibers will also be hydrophobic and will therefore be less likely to accept or wick aqueous fluids such as warp fluids. Therefore, when using such resins, additional measures may be included to make the fibers and / or nonwoven webs hydrophilic. In some configurations, a suitable surfactant may be applied to the nonwoven web after its formation. A particularly suitable surfactant finishing agent is SILASTOL PHP 26, a product of Schill+Seilacher GmbH, Böblingen, Germany. The finishing agent can be applied to the web using any suitable method (e.g., via a lick-roll coater). The finishing agent can be applied in an amount suitable to impart the desired level of hydrophilicity to the nonwoven web and thus contribute to imparting the desired level of capillary absorption / desorption pressure. In some configurations, the finishing agent coating of SILASTOL PHP 26 can be applied in an amount sufficient to constitute 0.30% to 0.60%, more preferably 0.40% to 0.50% of the basis weight of the nonwoven fiber web material after drying.

[0058] The wicking performance can also vary depending on how the fiber web is further processed, and can be manipulated in this way. Factors such as the level of consolidation (i.e., compaction) of the fiber clumps in the end structure and the orientation of individual fibers within the end structure can affect absorbency and wicking performance.

[0059] Therefore, for the purposes envisioned herein, in conjunction with the appropriate basis weight, density, and / or thickness as described above, it may be desirable to form a nonwoven fiber web material, spun from thermoplastic polymer resin and used for preparing the topsheet, in a partially or substantially integral form via a nonwoven fiber web manufacturing process, wherein most of the fibers are assigned an orientation including some z-direction orientation, rather than an orientation primarily along the processing direction of the fiber web structure or biased in the xy plane. Following any suitable process (e.g., via spunbonding) in which the fibers are distributed and laid on a horizontally shaped belt, additional process steps may be employed to force some fibers or portions thereof to reorient in the z-direction. Suitable process steps may include needle punching and hydroentangling or water-reinforced. Hydroentangling or water-reinforced may be desirable due to its effectiveness in reorienting fiber length while minimizing fiber breakage and forming less broken fiber lint and surface fluff (free fiber ends extending from the surface of the fiber web), wherein the high-speed water jets are directed to the wadding as it is conveyed through an array of fine, high-speed water jets. Vacuum dehydration systems (where air is drawn in the z-direction through the fiber web into a pattern of orifices or holes on a vacuum drum or belt conveying the wadding, thereby pulling the sprayed water along with it) are desirable because they tend to form, add, open, and / or clear small z-direction channels within the fibrous matrix of the fiber web, generally in the form of orifice or hole patterns. Without being bound by theory, it is believed that z-direction-oriented fiber portions and z-direction channels enhance the fiber web's ability and tendency to wick water-containing fluid in the z-direction. In a topsheet, this would mean that the material can more easily wick water-containing fluid from the wearer-facing surface of the topsheet to the outward-facing surface, i.e., downwards to the underlying absorbent layer, thereby wicking less fluid along the xy-plane direction (resulting in lateral and / or longitudinal diffusion of stains from the discharged fluid).

[0060] Absorption layer

[0061] In some configurations, the absorbent structure 40 may be formed of or include layers of absorbent open-cell foam material. The foam material may include at least a first layer 40a and a second layer 40b of absorbent open-cell foam material. Figure 3B These sublayers are in direct face-to-face contact with each other. In this configuration, the wearer-facing sublayer can be a relatively large open-cell foam material, and the outward-facing sublayer can be a relatively small open-cell foam material, for the purposes of further explanation below.

[0062] Open-cell foam materials can be foam materials manufactured by polymerization of a continuous oil phase of a water-in-oil high internal phase emulsion (“HIPE”).

[0063] The water-in-oil HIPE has two phases. One phase is a continuous oil phase containing the monomer to be polymerized and an emulsifier to help stabilize the HIPE. The oil phase may also include one or more photoinitiators. The monomer component may be included in the oil phase in an amount of about 80% to about 99% by weight, and in some examples about 85% to about 95%. The emulsifier component, soluble in the oil phase and suitable for forming a stable water-in-oil emulsion, may be included in the oil phase in an amount of about 1% to about 20% by weight. The emulsion can be formed at an emulsification temperature of about 20°C to about 130°C, and in some examples about 50°C to about 100°C.

[0064] Generally, monomers may be included in an amount of about 20% to about 97% by weight of the oil phase, and may contain at least one substantially water-insoluble monofunctional alkyl acrylate or alkyl methacrylate. For example, monomers of this type may include C4-C18 alkyl acrylates and C2-C18 alkyl methacrylates, such as ethylhexyl acrylate, butyl acrylate, hexyl acrylate, octyl acrylate, nonyl acrylate, decyl acrylate, isodecyl acrylate, tetradecyl acrylate, benzyl acrylate, nonylphenyl acrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, octyl methacrylate, nonyl methacrylate, decyl methacrylate, isodecyl methacrylate, dodecyl methacrylate, tetradecyl methacrylate, and octadecyl methacrylate.

[0065] The oil phase may also contain approximately 2% to approximately 40% by weight of the oil phase, and in some examples approximately 10% to approximately 30% of substantially water-insoluble multifunctional crosslinked alkyl acrylates or alkyl methacrylates. Such crosslinking comonomers or crosslinking agents are added to impart strength and elasticity to the resulting HIPE foam. Examples of this type of crosslinking monomer include monomers containing two or more activated acrylate, methacrylate, or combinations thereof. Non-limiting examples of such groups include 1,6-hexanediol diacrylate, 1,4-butanediol dimethacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, 1,12-dodecyl dimethacrylate, 1,14-tetradecanediol dimethacrylate, ethylene glycol dimethacrylate, neopentyl glycol diacrylate (2,2-dimethylpropylene glycol diacrylate), hexanediol acrylate methacrylate, glucose pentaacrylate, dehydrated sorbitol pentaacrylate, etc. Other examples of crosslinking agents include mixtures of acrylate and methacrylate portions, such as ethylene glycol acrylate-methacrylate and neopentyl glycol acrylate-methacrylate. In mixed crosslinking agents, the methacrylate:acrylate group ratio can be varied from 50:50 to any other ratio as needed.

[0066] Any third, substantially water-insoluble comonomer may be added to the oil phase from about 0% to about 15% by weight, or in some examples from about 2% to about 8% by weight, based on the weight of the oil phase, to modify the properties of the HIPE foam. In some cases, it may be desirable to “toughen” the monomers to impart toughness to the resulting HIPE foam. These include monomers such as styrene, vinyl chloride, vinylidene chloride, isoprene, and chloroprene. Without being bound by theory, such monomers are believed to help stabilize HIPE during polymerization (also known as “curing”) to provide a more uniform and better-formable HIPE foam, resulting in better toughness, tensile strength, abrasion resistance, etc. Monomers may also be added to impart flame retardancy, as disclosed, for example, in US 6,160,028. Monomers can be added to impart color (e.g., vinyl ferrocene); to impart fluorescence; to impart radiation resistance; to impart radio opacity (e.g., lead tetraacrylate); to disperse charge; to reflect incident infrared light; to absorb radio waves; to make the surface of HIPE foam strands or cell walls wettable; or to achieve any other desired properties of HIPE foam. In some cases, these additional monomers can slow down the overall process of HIPE transforming into HIPE foam, and trade-offs are necessary if desired properties are to be imparted. Therefore, such monomers can also be used to slow down the polymerization rate of HIPE. Examples of this type of monomer include styrene and vinyl chloride.

[0067] The oil phase may also contain emulsifiers to stabilize HIPE. Emulsifiers used in HIPE may include: (a) branched C16-C24 fatty acids, dehydrated sorbitol monoesters; straight-chain unsaturated C16-C22 fatty acids; and straight-chain saturated C12-C14 fatty acids, such as dehydrated sorbitol monooleate, dehydrated sorbitol monomyristate and dehydrated sorbitol monoester, dehydrated sorbitol monolaurate, diglyceride monooleate (DGMO), polyglycerol monoisostearate (PGMIS) and polyglycerol monomyristate (PGMM). (b) branched C16-C24 fatty acid polyglycerol monoesters, straight-chain unsaturated C16-C22 fatty acids, or straight-chain saturated C12-C14 fatty acids, such as diglyceride monooleates (e.g., diglyceride monoglycerides of C18:1 fatty acids), diglyceride monomyristate, diglyceride monoisostearate, and diglyceride monoesters; (c) branched C16-C24 alcohols diglyceride monoaliphatic ethers, straight-chain unsaturated C16-C22 alcohols, and straight-chain saturated C12-C14 alcohols, and mixtures of these emulsifiers. See US 5,287,207 and US 5,500,451. Another available emulsifier is polyglycerol succinate (PGS), which is formed from alkyl succinates, glycerol, and triglycerides.

[0068] Such emulsifiers and combinations thereof can be added to the oil phase such that they constitute about 1% to about 20% by weight of the oil phase, about 2% to about 15% in some examples and about 3% to about 12% in some other examples. In some configurations, co-emulsifiers may also be used to provide additional control over cell size, cell size distribution and emulsion stability, especially at higher temperatures, for example, above about 65°C. Examples of co-emulsifiers include phosphatidylcholine and phosphatidylcholine-containing compositions, aliphatic betaine, long-chain C12-C22 dialiphatic quaternary ammonium salts, short-chain C1-C4 dialiphatic quaternary ammonium salts, long-chain C12-C22 dialkylyl(enoyl)-2-hydroxyethyl, short-chain C1-C4 dialiphatic quaternary ammonium salts, long-chain C12-C22 dialiphatic imidazoline quaternary ammonium salts, short-chain C1-C4 dialiphatic imidazoline quaternary ammonium salts, long-chain C12-C22 monoaliphatic benzyl quaternary ammonium salts, long-chain C12-C22 dialkylyl(enoyl)-2-aminoethyl, short-chain C1-C4 monoaliphatic benzyl quaternary ammonium salts, and short-chain C1-C4 monohydroxy aliphatic quaternary ammonium salts. In some configurations, ditapyldimethylammonium methyl sulfate (DTDMAMS) can be used as a co-emulsifier.

[0069] Any photoinitiator included may be contained in amounts between about 0.05% and about 10% by weight of the oil phase, and in some configurations between about 0.2% and about 10%. Lower amounts of photoinitiator allow light to penetrate the HIPE foam more effectively, which allows polymerization to proceed deeper into the HIPE foam. However, if polymerization is carried out in an oxygen-containing environment, it may be desirable to have sufficient photoinitiator to initiate polymerization and overcome oxygen inhibition. Photoinitiators respond rapidly and efficiently to a light source, generating free radicals, cations, and other substances capable of initiating polymerization. Photoinitiators selected for forming the foam within the contemplation of this disclosure absorb UV light with wavelengths from about 200 nanometers (nm) to about 800 nm, and in some examples from about 250 nm to about 450 nm. If the photoinitiator is in the oil phase, suitable types of oil-soluble photoinitiators include benzyl ketal, α-hydroxyalkyl phenyl ketone, α-aminoalkyl phenyl ketone, and acylphosphine oxide. Non-limiting examples of suitable photoinitiators may include combinations of 2,4,6-[trimethylbenzoyldiphosphine]oxide and 2-hydroxy-2-methyl-1-phenylprop-1-one (a 50:50 blend of the two is sold by Ciba Specialty Chemicals, Ludwigshafen, Germany at DAROCUR 4265); benzyl dimethyl ketal (sold by Ciba Geigy at IRGACURE 651); α-,α-dimethoxy-α-hydroxyacetophenone (sold by Ciba Speciality Chemicals at DAROCUR 1173); 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-prop-1-one (sold by Ciba Speciality Chemicals at IRGACURE 907); 1-hydroxycyclohexyl-phenyl ketone (sold by Ciba Speciality Chemicals at IRGACURE 907). 184 for sale); bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide (sold by Ciba Speciality Chemicals at IRGACURE 819); diethoxyacetophenone and 4-(2-hydroxyethoxy)phenyl-(2-hydroxy-2-methylpropyl) ketone (sold by Ciba Speciality Chemicals at IRGACURE 2959); and oligo[2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]acetone] (sold by Lamberti spa, Gallarate, Italy at ESACURE KIP EM).

[0070] The aqueous dispersion phase of HIPE contains water and may also contain one or more components, such as initiators, photoinitiators or electrolytes, wherein in some examples, the one or more components are at least partially water-soluble.

[0071] One component included in the aqueous phase may be a water-soluble electrolyte. The aqueous phase may contain approximately 0.2% to approximately 40% (in some examples, approximately 2% to approximately 20%) of a water-soluble electrolyte by weight of the aqueous phase. The electrolyte minimizes the tendency for primarily oil-soluble monomers, comonomers, and crosslinking agents to also dissolve in the aqueous phase. Examples of electrolytes include chlorides or sulfates of alkaline earth metals (such as calcium or magnesium) and chlorides or sulfates of alkali metals (such as sodium). Such electrolytes may contain buffers for controlling the pH during polymerization; buffers include inorganic counterions such as phosphates, borates, and carbonates, and mixtures thereof. Water-soluble monomers may also be used in the aqueous phase, examples being acrylic acid and vinyl acetate.

[0072] Another component that may be included in the aqueous phase is a water-soluble free radical initiator. Based on the total moles of polymerizable monomers present in the oil phase, the initiator can be present in an amount of up to about 20 mol%. In some examples, the initiator may be included in an amount of about 0.001 mol% to about 10 mol% based on the total moles of polymerizable monomers in the oil phase. Suitable initiators may include ammonium persulfate, sodium persulfate, potassium persulfate, 2,2'-azobis(N,N'-dimethyleneisobutylamidine) dihydrochloride, azo initiators, redox pairs such as persulfate-hydrosulfate, persulfate-ascorbic acid, and other suitable redox initiators. In some configurations, to reduce the possibility of premature polymerization that could clog the emulsion system, the initiator may be added to the monomer phase near the end of the emulsification step or shortly after the end of the emulsification step.

[0073] The photoinitiator contained in the aqueous phase may be at least partially water-soluble and may constitute between about 0.05% and about 10% by weight of the aqueous phase, and in some examples between about 0.2% and about 10%. Lower amounts of photoinitiator allow light to penetrate the HIPE foam better, which allows polymerization to proceed deeper into the HIPE foam. However, if polymerization is carried out in an oxygen-containing environment, sufficient photoinitiator should be available to initiate polymerization and overcome oxygen inhibition. The photoinitiator responds rapidly and efficiently to a light source, generating free radicals, cations, and other substances capable of initiating the polymerization reaction. The photoinitiator selected for forming the foam within the contemplation of this disclosure may absorb UV light with wavelengths from about 200 nanometers (nm) to about 800 nm, in some examples from about 200 nm to about 350 nm, and in some examples from about 350 nm to about 450 nm. If the photoinitiator is to be contained in the aqueous phase, suitable types of water-soluble photoinitiators may include benzophenone, benzoin, and thioxanone. Examples of photoinitiators include 2,2'-azobis[2-(2-imidazolin-2-yl)propane] dihydrochloride; dehydrated 2,2'-azobis[2-(2-imidazolin-2-yl)propane] disulfate; 2,2'-azobis(1-imino-1-pyrrolo-2-ethylpropane) dihydrochloride; 2,2'-azobis[2-methyl-N-(2-hydroxyethyl)propionamide]; 2,2'-azobis(2-methylpropanediamine) dihydrochloride; 2,2'-dicarboxymethoxydibenzylacetone, 4,4'-dicarboxymethoxydibenzylacetone, 4,4'-dicarboxymethoxydibenzylcyclohexanone, 4-dimethylamino-4'-carboxymethoxydibenzylacetone; and 4,4'-disulfonylmethoxydibenzylacetone. Other suitable photoinitiators that may be used are listed in US 4,824,765.

[0074] In addition to the aforementioned components, other components may also be included in the aqueous or oil phase of HIPE. Examples include antioxidants, such as hindered phenols and hindered amine light stabilizers; plasticizers, such as dioctyl phthalate and dinonyl sebacate; flame retardants, such as halogenated hydrocarbons, phosphates, borates, and inorganic salts, such as antimony trioxide, ammonium phosphate, or magnesium hydroxide; dyes and pigments; fluorescent agents; filler particles, such as starch, titanium dioxide, carbon black, or calcium carbonate; fibers; chain transfer agents; odor absorbers, such as activated carbon particles; dissolved polymers; dissolved oligomers; and so on.

[0075] HIPE foam is produced by the polymerization of monomers comprising a continuous oil phase of HIPE. In some examples, the HIPE foam layer may have one or more sublayers and may be a homogeneous or heterogeneous polymer open-cell foam. Homogeneity and heterogeneity refer to different layers within the same HIPE foam that are similar in the case of homogeneous HIPE foam and different in the case of heterogeneous HIPE foam. Heterogeneous HIPE foam may contain at least two different sublayers that differ in their chemical composition, physical properties, or both; for example, the sublayers may differ in one or more of the following: foam density, polymer composition, specific surface area, or pore size (also known as cell size). For example, for HIPE foam, if the difference involves pore size, the average pore size in the corresponding sublayers may differ by at least about 20%, in some examples by at least about 35%, and in other examples by at least about 50%. Similarly, if the difference in the sublayers of the HIPE foam layer involves density, the density of the layers may differ by at least about 20%, in some examples by at least about 35%, and in other examples by at least about 50%. For example, if one layer of HIPE foam has a density of 0.020 g / cc, then another layer may have a density of at least about 0.024 g / cc or less than about 0.016 g / cc, at least about 0.027 g / cc or less than about 0.013 g / cc in some examples, and at least about 0.030 g / cc or less than about 0.010 g / cc in other examples. If the difference between layers relates to the chemical composition of HIPE or HIPE foam, the difference may reflect a relative difference in the amount of at least one monomer component, for example, a difference of at least about 20%, at least about 35% in some examples, and at least about 50% in other examples. For example, if one sublayer of HIPE or HIPE foam consists of about 10% styrene in its formulation, then another sublayer of HIPE or HIPE foam may consist of at least about 12%, and at least about 15% in some examples.

[0076] HIPE foam layers configured with different sublayers formed of different HIPEs can provide a range of desired performance characteristics. For example, when used in absorbent articles, a HIPE foam layer comprising a first foam sublayer and a second foam sublayer (where the first foam sublayer has a relatively larger pore size or cell size than the second layer) can absorb incoming fluid more quickly than the second layer. For example, when using HIPE foam layers to form the absorbent layer of a feminine hygiene pad, the first foam sublayer can be stacked on top of a second foam sublayer having a relatively smaller pore size compared to the first foam sublayer. The second foam sublayer applies greater capillary pressure and draws the collected fluid from the first foam sublayer, thereby restoring the ability of the first foam sublayer to collect more fluid from above. HIPE foam pore sizes can range from 1 μm to 200 μm, and in some examples can be less than 100 μm. The HIPE foam layer of this disclosure having two principal parallel surfaces can be from about 0.5 mm to about 10 mm thick, and in some examples from about 2 mm to about 10 mm thick. The desired thickness of the HIPE foam layer will depend on the material used to form the HIPE foam layer, the rate at which HIPE is deposited on the belt, and the intended use of the resulting HIPE foam layer.

[0077] The HIPE foam layer disclosed herein is relatively open-celled. This means that individual cells or pores in the HIPE foam layer are substantially unobstructed in communication with adjacent cells. Cells in such substantially open-cell HIPE foam structures have openings or windows between cells that are large enough to allow fluid to easily move from one cell to another within the HIPE foam structure. For the purposes of this disclosure, a HIPE foam is considered "open-celled" if at least about 80% of the cells with a pore size of at least 1 μm are in fluid communication with at least one adjacent cell.

[0078] In addition to being open-celled, in some examples, HIPE foam is also adapted to have sufficient hydrophilicity to allow the HIPE foam to absorb aqueous fluids. In some examples, the inner surface of the HIPE foam can be made hydrophilic by residual hydrophilizing surfactants or salts retained in the HIPE foam after polymerization, by selected post-polymerization HIPE foam treatment procedures (described below), or a combination of both.

[0079] In some configurations, such as when used to form the absorbent layer of feminine hygiene products, the HIPE foam layer can be flexible and exhibit an appropriate glass transition temperature (Tg). Tg represents the midpoint between the glassy and rubbery states of the polymer. Generally, HIPE foams with a Tg higher than the service temperature can be strong, but will also be relatively rigid and potentially prone to breakage (brittleness). In some examples, the regions of the HIPE foam of this disclosure exhibiting relatively high Tg or excessive brittleness will be discontinuous. Since these discontinuous regions will generally also exhibit high strength, they can be prepared at a lower density without compromising the overall strength of the HIPE foam.

[0080] HIPE foam intended for applications requiring flexibility should contain at least one continuous region with the lowest possible Tg, provided the entire HIPE foam maintains acceptable strength at the operating temperature. In some examples, for foam used at approximately ambient temperature, the Tg of this region will be below about 40°C; in some other examples, the Tg will be below about 30°C. For HIPE foam used in applications where the operating temperature is above or below ambient temperature, the Tg of the continuous region may be no more than 10°C higher than the operating temperature, in some examples the same as the operating temperature, and in other examples about 10°C lower than the operating temperature where flexibility is desired. Therefore, monomers of corresponding polymers with low Tg should be selected as much as possible.

[0081] The HIPE foams that can be used to form absorbent layers and / or sublayers within the scope of this disclosure, and the methods for manufacturing them, also include, but are not limited to, the foams and methods described in the following patents: US 10,045,890, US 9,056,412, US 8,629,192, US 8,257,787, US 7,393,878, US 6,551,295, US 6,525,106, US 6,550,960, US 6,406,648, US 6,376,565, US 6,372,953, US 6,369,121, US 6,365,642, US 6,207,724, US 6,204,298, US 6,158,144, US 6,107,538, US 6,107,356, US 6,083,211, US6,013,589, US 5,899,893, US 5,873,869, US 5,863,958, US 5,849,805, US 5,827,909, US5,827,253, US 5,817,704, US 5,817,081, US 5,795,921, US 5,741,581, US 5,652,194, US 5,650,222, US 5,632,737, US 5,563,179, US 5,550,167, US 5,500,451、U.S. US 5,387,207, US 5,352,711, US 5,397,316, US 5,331,015, US 5,292,777, US 5,268,224, US 5,260,345, US 5,250,576, US 5,149,720, US 5,147,345, and US 2005 / 0197414, US 2005 / 0197415, US2011 / 0160326, US 2011 / 0159135, US 2011 / 0159206, US 2011 / 0160321 and US 2011 / 0160689, are incorporated herein by reference to the extent that they are not inconsistent with this document.

[0082] like Figure 1 and Figure 2As reflected herein, the absorbent layer formed of HIPE foam may include one or more patterns of forward perforations 42f and backward perforations 42r, including at least a first pattern disposed near the intersection of the longitudinal axis 100 and the lateral axis 200 of the pad within the intended discharge location. The perforations 42f, 42r may be stamped, cut, molded, or otherwise formed to extend through the entire z-direction depth of the HIPE foam absorbent layer, or only through the wearer-facing layer or partially into its wearer-facing portion. When the HIPE foam absorbent layer is positioned in direct contact with the topsheet as described herein, in the absence of an intermediary collection layer formed of another material, the perforations 42f, 42r can serve as a set of reservoirs to receive, temporarily retain, and facilitate the rapid discharge of relatively small amounts of fluid until the HIPE foam has sufficient time to distribute and absorb the fluid via capillary action. Additionally, such perforations help reduce the flexural stiffness of the absorbent layer, which can help improve the comfort of the pad for the wearer. A perforation pattern with an average radius or other maximum dimension of 1.0 mm to 4.0 mm, and more preferably 1.5 mm to 3.5 mm, may be included within, for example, the area occupied by the adhesive region 25. The pattern may include a numerical density of 3.0 to 9.0 perforations / cm². 2 More preferably, it is 4.0 to 8.0 perforations / cm 2 The perforations. When selecting the appropriate average size, numerical density, and surface area occupied by the perforation pattern, the manufacturer may wish to balance the desired volume of the "reservoir" with the need to retain the absorbent material in a location close to the intended discharge location. Additional details regarding the configuration of such perforations in conjunction with examples of suitable absorbent layers can be found in US 8,211,078.

[0083] Preferably, the top sheet 20 is bonded to the wearer-facing surface of the absorbent layer 40 in a manner that ensures close proximity between the two, providing rapid fluid movement downwards through the top sheet to the absorbent layer 40 without creating unacceptable blockages that would impede downward fluid movement (e.g., excessive deposits from the adhesive between these components). Bonding the top sheet to the absorbent layer also helps to secure the absorbent layer 40 within the encapsulation space and contributes to a unified overall structure of the pad, thereby enhancing the user / wearer's impression of quality. The top sheet 20 can be bonded to the absorbent layer 40 in any suitable manner, including as described in U.S. Patent Application Serial No. 16 / 789,522. By effectively integrating the absorbent layer 40 and the top sheet 20, this bonding also helps to reduce any possibility of the pad folding or wrinkling along a series of perforations, thereby further guiding and facilitating articulation or folding along the large pore path as envisioned herein. To further integrate the pad and minimize the formation of open spaces (spaces not occupied by absorbent material) between the top and bottom sheets, the outward-facing surface of the absorbent layer can also be bonded to the bottom sheet via a deposition pattern or dispersion of an adhesive applied between these components, to the wearer-facing surface of the bottom sheet 30 or the outward-facing surface of the absorbent layer 40.

[0084] Large gap

[0085] See Figures 4A to 4D The absorbent layer 40 may be provided with an arrangement of large voids 51. As contemplated herein, the large voids 51 may have similarity to the perforations 42f and 42r described above, as they are visible voids formed in the absorbent layer 40. However, for the purposes contemplated herein, they are distinguished in that the large voids 51 are intended to facilitate or promote generally longitudinal folding or folding of the absorbent layer 40. Conversely, the forward perforation 42f serves as a fluid reservoir as described above, and the backward perforation 42r serves as a fluid reservoir or channel, and also facilitates or promotes generally lateral bending / curvature of the pad upward around the wearer's hips at the rear. In some configurations, for the large voids 51 to function more reliably as described below, it may be desirable for the large voids 51 to have an xy-plane aspect ratio of at least 1.5:1, more preferably at least 2:1, wherein their longer dimensions are oriented substantially along paths such as paths 50f, 50r.

[0086] It is understood that the arrangement of large gaps in the absorbent layer 40, which gives it the features described herein, can significantly improve the ability of the pad 10 to conform closely to the wearer's body in the crotch area while maintaining the wearer's comfort.

[0087] A suitable arrangement may include a path with a large gap 51, comprising a left-forward path and a right-forward path 50f arranged substantially symmetrically around the longitudinal axis 100 and on either side of the longitudinal axis 100, and a rearward path 50r substantially centered along and / or substantially following the longitudinal axis 100. The left-forward path leg may be primarily positioned in front of the lateral axis 200, starting at a left-center position near the intersection of the lateral axis 200 and the longitudinal axis 100, and ending at a left-outer position positioned in front of the first left-center position and further outward than the first left-center position along the longitudinal axis 100. The right-forward path leg may be primarily positioned in front of the lateral axis 200, starting at a right-center position near the intersection of the lateral axis 200 and the longitudinal axis 100, and ending at a right-outer position positioned in front of the first right-center position and further outward than the first right-center position along the longitudinal axis 100. The rearward path leg may be primarily positioned behind the lateral axis 200.

[0088] Each of the left forward path and the right forward path 50f may have a first endpoint 50fe1, which is located relatively closer to the longitudinal axis 100 and closer to the intersection (referred to herein as the "center") of the pad's axes 100 and 200 than the second endpoint 50fe2. The backward path 50r may have a first endpoint 50re1 located relatively closer to the lateral axis 200 than the second endpoint 50re2. It may be desirable that the left forward path and the right forward path 50f not completely converge or intersect, for example, at or near the longitudinal axis 100, in order to maintain the structural integrity of the foam layer by avoiding an increase in the possibility of tear propagation beyond the path, which could be due to manipulation or movement of the foam layer during pad manufacturing, pad handling, or pad use / wearing. For similar reasons, it may be desirable that the forward path 50f does not meet or intersect with the backward path 50r.

[0089] See details Figures 4C to 4F Through prototyping and testing, it has been learned that the arrangement of the large gaps 51 with these features facilitates the folding or hinge of the absorbent layer 40 around paths 50f and 50r. This is more easily achieved when the absorbent layer 40 is formed of a flexible foam such as polyurethane foam or HIPE foam as described herein. Testing has shown that when a pad with some or any combination of these features is properly positioned and applied to the user's / wearer's underwear and then worn normally, areas 40fl and 40fr tend to flex upward (or toward the wearer's body) around the folds formed along path 50f along the large gaps 51, thus giving the pad a cup-shaped configuration (in lateral cross-section) that better conforms to the wearer's body in the area near the vagina. (See...) Figure 4EMeanwhile, zones 40rl and 40rr tend to flex downwards (or away from the wearer's body) around the folds formed along path 50r of the large gap 51, thus giving the pad an inverted V-shaped configuration (in lateral cross-section), which better conforms to the wearer's body along the hip crease. (See also...) Figure 4F When the absorbent layer 40 is formed of a suitable foam such as polyurethane or HIPE foam, the flexibility and elasticity of the foam can better allow the absorbent layer 40 to buckle and transition between the two configurations in the transition zone 40t.

[0090] See Figure 4G And, as with 4H, these conformal tendencies can be synergistically enhanced by patterns including and combining with perforations 42f and 42r, as described above. Suitable patterns of perforations 42f, primarily or entirely located between the left and right anterior paths 50f (such as, for example...) Figure 4G and Figure 4H The pattern shown not only serves the storage and dispensing functions described above, but also increases the flexibility and suppleness of the absorbent layer 40 in this area, enhancing its ability to cup around the user / wearer's body in the area near the vagina.

[0091] A suitable pattern of pores 42r can be matched with large voids 51 in the rearward portion of the absorbent layer 40 so that the rearward portion of the layer 40 can bend and wrap upward around the wearer's hips (as viewed from the side), while simultaneously folding along the longitudinal axis 100 to better conform to the wearer's body within and near the hip crease. It should be understood that attempting to make a generally flat / planar material conform to such a complex curved and intersecting surface can be difficult.

[0092] In some configurations, it may be preferred that the path of the large void 51 traverses or covers more than two, more preferably more than three, even more preferably more than four, and even more preferably more than five large voids 51, wherein a continuous area of ​​the absorbent layer material lies between the large voids. In some configurations, it may be preferred that the path of the large void 51 traverses or covers about 2 to about 18 large voids (where a continuous area of ​​the absorbent layer material lies between the large voids 51), or about 4 to about 15 large voids 51, or about 6 to about 12 large voids 51, or about 8 to about 10 large voids 51. Providing a continuous area of ​​material between consecutive large voids 51 along the path reduces or prevents the large voids from guiding fluid along their guiding flow (which could have undesirable consequences), and also helps the absorbent layer maintain structural robustness and avoid its undesirable tearing, while still facilitating desired wrinkling along the path. In some configurations, the continuous area of ​​material along the path between the continuous large gaps 51 may have a gap length (G) of about 2 mm to about 6 mm, or about 3 mm to about 5 mm.

[0093] In the case where a generally laterally oriented perforation 42r (as described herein) is included together with a path 50r of a large void 51 as described herein, it may be desirable that the large void 51 and the laterally oriented perforation 42r do not intersect or overlap, that is, again for the purpose of maintaining the structural robustness of the absorbing layer 40, there is a continuous area of ​​material between the large void 51 and the perforation 42r.

[0094] like Figure 4H As shown, in some configurations, it may be preferred to have more than one left and / or right forward path 50f with large gaps. For example, suitable arrangements may include a first left forward path 50fl1 and a second left forward path 50fl2 and / or a first right forward path 50fr1 and a second right forward path 50fr2. In some configurations, the distance (D1) between the first left forward path 50fl1 and the second left forward path 50fl2 and / or between the first right forward path 50fr1 and the second right forward path 50fr2 may be from about 2 mm to about 6 mm, or from about 3 mm to about 4 mm.

[0095] In some configurations, the large gaps of the first left-forward path 50fl1 and the second left-forward path 50fl2 may be staggered. In some configurations, the large gaps of the first right-forward path 50fr1 and the second right-forward path 50fr2 may be staggered. The first left-forward path 50fl1 and the second left-forward path 50fl2 and / or the first right-forward path 50fr1 and the second right-forward path 50fr2 may be substantially the same length or may be different lengths. In some configurations, the second left-forward path 50fl2 may include more large gaps and / or may be longer than the first left-forward path 50fl1, or vice versa. In some configurations, the second right-forward path 50fr2 may include more large gaps and / or may be longer than the first right-forward path 50fr1, or vice versa.

[0096] See Figure 5 , Figure 11A and Figure 11B It is desirable that the large void along the path has a width mvw of 20% to 300%, preferably 50% to 150%, and even more preferably 75% to 125% of the thickness clpr of the absorber layer 40. Limiting the width of the large void to values ​​within these ranges helps ensure that the desired level of flexibility is provided so that it can be easily folded or wrinkled along the path of the large void, while avoiding a large void of such size that it is an open opening through the absorber layer that allows liquid to move uncontrollably through it into the space between the absorber layer 40 and the substrate 30. When the top sheet 20 is bonded to the absorber layer 40 as described above, its bridging portion 20m of the large void constrains the separation of the absorber layer 40 across the large void 51 as it bends around the path of the large void (as can be compared). Figure 11A and11B (Understood). This causes the portion of the absorbent layer 40 on the inside of the wrinkle or crease to be pulled together (e.g., Figure 11B As shown), thereby advantageously closing the openings or gaps in the absorber layer provided by the large voids 51. The portion 30m of the film 30 bridging the large voids 51 can be, for example, Figure 11B The shape is warped in the manner shown to accommodate folds or wrinkles. In relation to... Figure 11B When bending / wrinkling / folding occurs in the opposite direction, the roles of the top and bottom sheets are reversed, and the gaps in the absorbent layer with large voids close at the top, instead of as shown. Figure 11B The structure closes at the bottom. (For the purposes of this document, the width of the large gap is its maximum dimension anywhere the path traverses it, along the direction perpendicular to the path, and in the plane of the absorbent layer facing the wearer; see, for example...) Figure 5 and Figure 7 The dimension mvw is shown in the figure. The thickness clpr of the absorber layer is measured using the thickness measurement method provided below.

[0097] In other examples, but for similar purposes, large voids 51 may be formed in or imparted to the absorption layer such that they do not extend through the entire z-direction depth / thickness of the absorption layer 40 in the z-direction, but only partially extend through the absorption layer; see also Figure 12 The example shown.

[0098] The large gap 51 may have a length of about 2 mm to about 10 mm, or about 2.5 mm to about 8 mm, or about 3 mm to about 6 mm. In some configurations, a large gap 51 with a length of about 2 mm to about 6 mm may be preferred. Without being theoretically limited, it is believed that a large gap with a length of less than about 6 mm can help minimize tearing during high-speed processing.

[0099] A particularly suitable configuration may include a large gap 51 with a forward path 50f of about 4 mm in length, wherein the gap length (G) between the large gaps is about 3 mm.

[0100] A particularly suitable configuration may include a large gap 51 with a backward path 50r of about 3 mm in length, wherein the gap length (G) between large gaps and / or between a large gap and a perforation 42r intersecting the path of the large gap is about 3 mm.

[0101] In some configurations, the path of the large void 51 may have a ratio of large void length to gap length of about 30:1 to about 1:5, or about 10:1 to about 1:1.

[0102] Large voids 51 (and accompanying perforations 42f, 42r, if included) may be formed in or imparted to the absorbent layer 40 by any suitable method or process. In some configurations, they may be mechanically cut, die-cut, or punched through the absorbent layer or its precursor web or sheet. In some configurations, the process may include passing the layer (or precursor material in the web or sheet) through a gap between a pair of die-cutting rollers configured to cut the large voids (and perforations, if included) through the layer, web, or sheet in a desired arrangement. In some examples, the same die-cutting rollers may be configured to cut both the perforations 42f, 42r and the large voids 51. In such examples, the resulting peripheral edges and inner walls of the large voids (and perforations, if included) will have visible evidence of such mechanical cutting. In other examples, material can be removed from the absorbent layer (or precursor material in the form of a fiber web or sheet) via other methods configured to remove material along a defined contour to form the desired large void shape. These methods include, but are not limited to, laser cutting, fluid or water jet cutting, or etching. In other configurations, the material used to form the absorbent layer can be formed in or on a mold configured to mold a desired arrangement of large voids 51, with or without perforations 42f and / or 42r, into the absorbent layer (or precursor material). However, mechanical cutting or stamping, or fluid jet cutting or etching, may be preferred because these methods leave cut, open, exposed cells or holes in the absorbent layer material along the peripheral edges / walls of the exposed large voids (and perforations, if included), which can enhance fluid distribution and absorbency.

[0103] See Figure 4I In some configurations, it may be desirable to add a shaped reinforcement 60 below the absorbent layer 40 (i.e., on the outward-facing side of the absorbent layer). The reinforcement 60 may be a partial layer component shaped and adapted to impart increased flexural resistance to one or more selected areas of the pad occupied by the absorbent layer 40, to engage with the path of the large void 51 to guide and / or more effectively induce hinges and folds or wrinkles along it, and to reduce or avoid folds / wrinkles of the pad in unwanted locations. Therefore, in configurations including the reinforcement 60, it may be desirable for the reinforcement 60 to be located below one or more areas of the absorbent layer 40 not occupied by the large void 51. Figure 4IIn the example shown, the reinforcement 60 is located below the region between the left and right paths of the large void 51, primarily in the forward region of the pad (i.e., primarily in front of the lateral axis 200), and spans the longitudinal axis 100 and is substantially symmetrical thereto. This feature allows the absorbent layer 40 to more easily wrinkle along the left and right paths of the large void 51 as intended, and also resists excessive bending or wrinkling in unwanted locations (e.g., the intermediate region between the left and right paths). This is achieved in a pattern including the pores 42f located between the left and right paths of the large void 51 (e.g., as shown in the image). Figure 4G and Figure 4H The configuration shown may be desirable, otherwise it could reduce the stiffness of the absorbing layer 40 in that region. A reinforcement 60 may be added to be located below part or all of the pattern of pores 42f.

[0104] The reinforcement 60 may be formed or comprised of an additional shaped section of nonwoven fiber web material, film, tissue paper, paper, or any other additional material, which imparts additional flexural stiffness to the selected and defined area of ​​the pad occupied by the absorbent layer 40. In some configurations, the reinforcement 60 may be formed or comprised simply of an additional or super-weighted deposit of adhesive between the absorbent layer 40 and the substrate 30, having a defined shape configured to impart stiffness to the respective defined area of ​​the pad. In other configurations, the reinforcement 60 may be formed or comprised of an application of additional or weighted fastening adhesive 35 applied to the outward-facing surface of the substrate in the area requiring additional reinforcement, as described above. In this configuration, when a user places and adheres the pad to her underwear for use / wearing, the desired additional stiffness is achieved along the contact surface area and in the area of ​​desired additional stiffness by increasing and / or relatively more continuous contact surface area and by the bonding / adhesion of the pad structure to the underwear fabric.

[0105] In other configurations, one or more portions or areas of the pad occupied by the absorbent layer 40 may be subject to selective mechanical deformation via a deformation roller, as described in U.S. Application Serial No. 63 / 424,979, in a manner that increases the flexibility / susceptibility of the absorbent layer 40 in the selected areas, and thus increases the flexibility / susceptibility of the pad. See also Figure 4D In some configurations, the transition region 40t can undergo such selective deformation to increase its deflection and resistance to bending. Figure 4E The transformation of the folded / cup-shaped configuration reflected in the middle to Figure 4FThe ability to reflect the folds / inverted "V" configuration. In other configurations, one or more peripheral edge regions of the absorbent layer 40 may be selectively deformable to increase the flexibility and suppleness of the absorbent layer 40 around the region near or adjacent to its xy-plane peripheral edge 41. In some configurations, a portion or preferably most of the xy-plane surface area of ​​the pad, including the surface area of ​​the absorbent layer 40 disposed behind the lateral axis 200, may be mechanically deformable as described above; this enhances the ability of the pad to conform to the user's / wearer's body and move with the user's / wearer's body along the contour of the hip seam. Additionally or alternatively, in some configurations, a portion or preferably most of the xy-plane surface area of ​​the pad, including the surface area of ​​the absorbent layer 40 disposed laterally on the left and right front path leg sections 50f, may be mechanically deformable as described above; this enhances the ability of the pad to conform to the user's / wearer's body and move with the user's / wearer's body in the crotch area with a slit (i.e., where the leg meets the lower torso). However, in such configurations, it may be desirable to avoid mechanical deformation of portions of the absorbent layer (40) that include the paths of the large voids 50f, 50r, or the large void 51 themselves, in order to avoid undesirable damage to the pad structure. When the pad is mechanically deformed as described in U.S. Application Serial No. 63 / 424,979, the foam layer will have visible evidence of such deformation in the form of tearing or fracturing along the z-direction in the area subjected to such deformation.

[0106] negative

[0107] The film 30 may be positioned adjacent to the outward-facing surface of the absorber layer 40 and may be bonded thereto by any suitable attachment method. For example, the film 30 may be secured to the absorber layer 40 by a uniform, continuous layer of adhesive, a patterned layer of adhesive, or an array of separate adhesive lines, spirals, or dots. Alternatively, the attachment method may include thermal bonding, pressure bonding, ultrasonic bonding, dynamic mechanical bonding, or any other suitable attachment mechanism or combination thereof. In other configurations, it is conceivable that the absorber layer 40 is not directly bonded to the film 30.

[0108] The backing sheet 30 may be impermeable or substantially impermeable to liquids (e.g., urine, menstrual fluid) and may be made of a thin plastic film, but other flexible materials impermeable to liquids may also be used. As used herein, the term "flexible" refers to a material that is compliant and readily conforms to the general shape and contours of the human body. The backing sheet 30 prevents or at least substantially inhibits the escape of fluids absorbed and contained within the absorbent layer 40 from reaching clothing articles, such as underwear and outerwear, that may come into contact with the pad 10. However, in some cases, the backing sheet 30 may be made and / or adapted to allow vapors to escape from the absorbent layer 40 (i.e., the backing sheet is made breathable), while in other cases, the backing sheet 30 may be made so as not to allow vapors to escape (i.e., it is made impermeable). Thus, the backing sheet 30 may comprise a polymer film, such as a thermoplastic film of polyethylene or polypropylene. Suitable materials for the backing sheet 30 are, for example, thermoplastic films with a thickness of about 0.012 mm (0.5 mils) to about 0.051 mm (2.0 mils). Any suitable film known in the art can be used in this invention.

[0109] Suitable examples of film are described in US 5,885,265, US 4,342,314, and US 4,463,045. Suitable single-layer breathable film for use herein includes those described, for example, in GB A 2184 389, GB A 2184 390, GB A 2184 391, US 4,591,523, US 3,989 867, US 3,156,242, WO 97 / 24097, US 6,623,464, US 6,664,439, and US 6,436,508.

[0110] The film may have two layers: a first layer comprising a breathable porous membrane layer and a second layer comprising a breathable microporous membrane layer, as described in US 6,462,251. Other suitable examples of two- or multi-layer breathable films used herein include those described in US 3,881,489, US 4,341,216, US 4,713,068, US 4,818,600, EP 203 821, EP 710471, EP 710 472, and EP 0 793 952.

[0111] Thickness measurement

[0112] The caliper or thickness of the test sample of the absorber layer 40 is measured as the distance between the reference platform on which the sample is placed and the pressure foot on which a specified amount of pressure is applied to the sample for a specified amount of time. All measurements are performed in a laboratory maintained at 23°C ± 2°C and 50% ± 2% relative humidity, and the test sample is conditioned in this environment for at least 2 hours prior to testing.

[0113] Thickness is measured using a manually operated micrometer equipped with a pressure foot capable of applying a stable pressure of 2.0 kPa ± 0.01 kPa to the test sample. This manually operated micrometer is a statically heavy instrument with readings accurate to 0.001 mm. A suitable instrument is the Mitutoyo Series 543 ID-C Digimatic, or equivalent, purchased from VWR International. The pressure foot is a flat, circular, movable surface with a diameter smaller than the test sample, capable of applying the required pressure. A suitable pressure foot has a diameter of 25.4 mm, but smaller or larger pressure feet can be used depending on the size of the sample being measured. The test sample is supported by a horizontal, flat reference platform that is larger than and parallel to the surface of the pressure foot. The system is calibrated and operated according to the manufacturer's instructions.

[0114] If necessary, the test sample is obtained by removing it from the absorbent article. When removing the test sample from the absorbent article, care should be taken not to cause any contamination or dimensional deformation to the test sample layer. The test sample should be taken from an area without creases or wrinkles and must be larger than the pressure foot.

[0115] To measure thickness, first zero the micrometer relative to a horizontal, flat reference platform. Place the test sample 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 sample. Wait 5 seconds, then record the thickness of the test sample to an accuracy of 0.01 mm. Repeat this process for a total of five duplicate test samples. Calculate the arithmetic mean of all thickness measurements and report it as “Fiber Web Thickness” to an accuracy of 0.01 mm.

[0116] Example

[0117] Based on the above disclosure, the following embodiments are envisioned:

[0118] 1. A feminine sanitary pad, the feminine sanitary pad having a liquid-permeable top sheet (20), a liquid-impermeable bottom sheet (30), an absorbent layer (40) encapsulated between the top sheet and the bottom sheet, a forward end, a rearward end, and a longitudinal axis (100) and a lateral axis (200), the axes having an intersection point,

[0119] The absorbent layer (40) includes an open-cell foam layer having a thickness in the z-direction and an outer periphery (41) along the xy-plane, wherein the foam layer has an arrangement of large voids (51) having a depth in the z-direction, wherein the arrangement of the large voids defines a path (50f, 50r) along the xy-plane surface of the foam layer and includes:

[0120] A left forward path leg (50f) is primarily positioned in front of the lateral axis, beginning at a left center position near the intersection of the axes, and ending at a left outer position positioned in front of a first left center position and further outward from the longitudinal axis than the first left center position; and

[0121] The right forward path leg (50f) is mainly located in front of the lateral axis and begins at the right center position near the intersection of the axis and ends at the right outer position located in front of the first right center position and further outside the longitudinal axis than the first right center position.

[0122] 2. The feminine sanitary pad according to Embodiment 1, wherein the arrangement of the large gaps further includes a rearward path leg (50r) disposed substantially along the longitudinal axis and primarily behind the lateral axis.

[0123] 3. The feminine sanitary pad according to Example 2, wherein one or more, preferably most, and more preferably all of the large gaps traversed by the rearward path leg (50r) do not intersect or overlap with any present rearward elongated perforations (42r) having their longest dimension oriented primarily in the lateral direction.

[0124] 4. The feminine sanitary pad according to any of the foregoing embodiments, wherein the absorbent layer has an arrangement of one or more rearward elongated perforations (42r) placed along the xy-plane surface of the pad, primarily disposed behind the lateral axis, wherein the longest dimension of the rearward elongated perforation is oriented primarily in the lateral direction.

[0125] 5. The feminine sanitary pad according to any of the foregoing embodiments, wherein the absorbent layer has an arrangement of one or more forward perforations (42f) placed along the xy-plane surface of the pad, primarily disposed between the left forward path leg and the right forward path leg.

[0126] 6. The feminine sanitary pad according to any of the foregoing embodiments, wherein at least some, preferably most, of the z-direction depth of the large voids extends completely through the thickness of the foam layer.

[0127] 7. The feminine sanitary pad according to any one of embodiments 1 to 4, wherein at least some, preferably most of, of the z-direction depth in the large gaps extends only partially through the thickness of the foam layer, and preferably, wherein the z-direction depth is 40% to 70% of the thickness of the foam layer, and preferably, wherein the z-direction depth begins and extends from the wearer-facing side of the foam layer.

[0128] 8. The feminine sanitary pad according to any of the foregoing embodiments, wherein one or more of the path legs traverse at least four, preferably at least five large gaps.

[0129] 9. The feminine sanitary pad according to any one of the foregoing embodiments, wherein each of the large gaps in each of the path legs along the path leg has a width, and the width is equal to 20% to 200%, more preferably 50% to 150%, and even more preferably 75% to 125% of the thickness in the z-direction.

[0130] 10. The feminine sanitary pad according to any one of the foregoing embodiments, wherein the open-cell foam is one or more of HIPE foam and polyurethane foam, preferably HIPE foam.

[0131] 11. The feminine sanitary pad according to any of the foregoing embodiments, wherein the periphery tapers from a laterally wider xy dimension in the rear portion of the pad to a laterally narrower xy dimension in the front portion of the pad.

[0132] 12. The feminine sanitary pad according to any of the foregoing embodiments, comprising a reinforcement (60) located below one or more portions of the absorbent layer.

[0133] 13. The feminine sanitary pad according to Example 12, wherein the reinforcement is not located below most of the large gap (51).

[0134] 14. A feminine sanitary pad according to any one of Embodiments 12 or 13, wherein the reinforcement has an xy surface area mainly disposed in front of the lateral axis (200).

[0135] 15. A feminine sanitary pad according to any one of embodiments 12 to 14, wherein the reinforcement has an xy surface area that is at least partially and more preferably mainly disposed between the left forward path leg and the right forward path leg (50f).

[0136] 16. A feminine sanitary pad according to any of the foregoing embodiments, wherein the foam layer has an xy-plane surface area, and the pad includes a portion of the xy-plane surface area of ​​the foam layer disposed behind the lateral axis (200), and preferably is substantially mechanically deformable.

[0137] 17. A feminine sanitary pad according to any of the foregoing embodiments, wherein the foam layer has an xy-plane surface area, and the pad includes a portion of the xy-plane surface area of ​​the foam layer disposed laterally on the left forward path leg and the right forward path leg (50f), and preferably is substantially mechanically deformable.

[0138] * * *

[0139] 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”.

[0140] To the extent that it does not contradict, 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 beneficial to this application, 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.

[0141] While specific embodiments of the invention have been illustrated and described by way of example, it will be apparent to those skilled in the art that various 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. A feminine hygiene pad comprising: a forward end, a rearward end, and a longitudinal axis and a lateral axis, the axes having an intersection; a liquid permeable topsheet; a liquid impermeable backsheet; and an absorbent layer disposed between the topsheet and the backsheet; wherein the absorbent layer comprises an open cell foam layer having a z-direction thickness and an outer periphery along an x-y plane, the open cell foam layer comprising a placement of large voids therein, the large voids having a z-direction depth, wherein the placement of large voids defines a path laid along the x-y plane surface of the open cell foam layer and comprises: a left forward path leg disposed primarily forward of the lateral axis and beginning at a left center location proximate the intersection of the axes and ending at a left outer location disposed forward of and more outward of the longitudinal axis than a first left center location; and a right forward path leg disposed primarily forward of the lateral axis and beginning at a right center location proximate the intersection of the axes and ending at a right outer location disposed forward of and more outward of the longitudinal axis than a first right center location.

2. The feminine hygiene pad of claim 1, wherein the placement of large voids further comprises a rearward path leg disposed substantially along the longitudinal axis and primarily rearward of the lateral axis.

3. The feminine hygiene pad of claim 1 or 2, wherein the absorbent layer comprises one or more forward perforation placements laid along the x-y plane surface of the pad, wherein the forward perforations are disposed between the left forward path leg and the right forward path leg.

4. The feminine hygiene pad of any of the preceding claims, wherein the z-direction depth of a portion of the large voids extends completely through the thickness of the foam layer.

5. The feminine hygiene pad of any of claims 1-3, wherein the z-direction depth of a portion of the large voids is 40% to 70% of the thickness of the foam layer, wherein the z-direction depth begins and extends from the wearer-facing side of the foam layer.

6. The feminine hygiene pad of any of the preceding claims, wherein one or more of the path legs traverses at least four large voids.

7. The feminine hygiene pad of any of the preceding claims, wherein each of the large voids along each of the path legs has a width, and the width is equal to 20% to 200% of the z-direction thickness.

8. The feminine hygiene pad of any of the preceding claims, wherein the open cell foam is one or more of a HIPE foam and a polyurethane foam.

9. The feminine hygiene pad of any of the preceding claims, wherein the placement of large voids further comprises a second left forward path leg disposed outward of the left forward path leg.

10. The feminine hygiene pad of claim 9, wherein the second left forward path leg extends substantially parallel to the left forward path leg.

11. The feminine hygiene pad of claim 10, wherein the left forward path leg and the second left forward path leg are separated by a distance of 2 mm to 4 mm.

12. The feminine hygiene pad of claim 9, wherein the arrangement of macrovoids further comprises a second right forward path leg.

13. The feminine hygiene pad of claim 12, wherein the second right forward path leg extends substantially parallel to the right forward path leg.

14. The feminine hygiene pad of any of the preceding claims, further comprising a stiffener positioned beneath one or more portions of the absorbent layer.

15. The feminine hygiene pad of any of the preceding claims, wherein at least one of the left forward path leg and the right forward path leg has a ratio of macrovoid length to gap length of about 30: 1 to about 1 :5.

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