Patent Publication Number: US-2005124959-A1

Title: Absorbent articles with asymmetric protective wing portions

Description:
FIELD OF THE INVENTION  
      The present invention relates generally to the field of disposable absorbent articles, and more particularly to a feminine care article having laterally extending protective wings.  
     BACKGROUND  
      Disposable absorbent articles intended to be worn in the crotch portion of an undergarment are well known. The basic form of such absorbent articles typically includes a body-side liquid-permeable top cover, a garment-side liquid-impermeable baffle, and an absorbent core positioned between the top cover and the baffle. Such absorbent articles are now in wide use as sanitary napkins, panty shields, panty liners, and adult incontinence pads. While this invention is directed to all such products, for purposes of simplification, the invention will be described with reference to a sanitary napkin.  
      In an effort to provide enhanced protection, it is known to provide conventional disposable absorbent articles with laterally extending flaps or wing portions intended to be folded around the edges of the wearer&#39;s undergarment. The wings offer some functional improvements and advantages over articles without such devices. First, the wings protect the edges of the wearer&#39;s undergarment from being soiled by bodily fluids. Second, the wings help to stabilize the sanitary napkin from shifting out of place, especially when the panels are affixed to the underside of the garment. Typically, each wing is either integral with the cover and/or the baffle or can be fashioned from separate pieces of material and permanently adhered or otherwise attached to the article so as to extend laterally from the sides of the article.  
      Conventional wing designs are generally symmetric and define a laterally outboard region that extends across the crotch region of the wearer&#39;s undergarment and attaches to the undergarment or to the opposite wing. Because of the their symmetric design and placement relative to the longitudinal dimension of the article, the attaching regions extend laterally along a transverse centerline of the absorbent article and, thus, attach around the center portion of the undergarment&#39;s crotch region. However, this attachment location may be problematic for certain users.  
      For example, the middle or inner crotch region of the undergarment to which the conventional wings are attached, is continually distorted, twisted and stretched due to the dynamics of the wearer. As a result, the wing attachment mechanism is subjected to substantial stresses and frequently detaches in use causing the wings and article to shift.  
      Also, the wings may be problematic in their placement and retention in the middle crotch area of the undergarment, particularly when the undergarment remains on the wearer and is simply lowered by the wearer prior to placement of the article. Usually, when the wearer is ready to use the absorbent article, a release liner is peeled from an adhesive on the baffle side of the article and the article is then pressed into the crotch region of the undergarment. The wings are then folded around the crotch region and secured on the underside of the undergarment, either affixed to the garment-facing side of the undergarment or to each other. This process requires the wearer to reach the lowermost portion of the undergarment and manipulate the wings in an awkward location and generally without being able to see the wings. Once the adhesive has been exposed and the article placed into the crotch region of the undergarment, it is generally not practical to remove and reposition the article.  
      It is also the case that the centrally disposed asymmetric wings are not optimally positioned for all styles of undergarments. For example, the crotch region of many undergarment styles taper significantly from the waist regions with the narrowest section of the crotch region to which the wings are attached actually being narrower than the pad component of the article. Attachment of the wings in this location serves little purpose.  
      The present invention provides an absorbent article with a unique wing configuration that addresses the drawbacks of conventional designs described above.  
     SUMMARY  
      Objects and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the invention.  
      Although the present invention has particular usefulness in the field of feminine care articles such as panty shields, liners and sanitary napkins, it should be appreciated that any manner of personal care absorbent article may benefit from the invention, including incontinence articles, and the like. All such uses are within the scope and spirit of the invention. For ease of description only, the working environment of the invention is assumed to be feminine care sanitary napkins.  
      In a particular embodiment of the invention, an absorbent article is provided for placement in the crotch region of an undergarment. The article includes a pad component having conventional features such as a generally liquid permeable top cover, a generally liquid impermeable outer cover or baffle, and an absorbent structure disposed between the top cover and baffle. The invention is not limited to any particular pad shape or configuration. Protective wing portions extend laterally outward from lateral sides of the pad component, the wing portions having dimensions so as to wrap at least partially around the crotch region of the wearer&#39;s undergarment. The wing portions have laterally outboard regions that overlap when the wings are folded around the crotch region of the wearer&#39;s undergarment. The wings may be portions of individual flap or panel structures that are adhered or otherwise attached to the baffle side of the pad. In an alternate embodiment, the wing portions may be components of a unitary flap or panel component that is attached to the baffle. In another embodiment, the wing portions may be defined as lateral extensions of the baffle material.  
      The wing portions extend longitudinally along both sides of a transverse centerline of the pad and have an asymmetric shape such that the overlap regions are disposed forward of the transverse centerline of the pad. For example, the wing portions may extend along about two-thirds of the lateral sides of the pad, and may extend equally on each side of the transverse centerline with the overlap region disposed entirely at the forward part of the pad (forward of the transverse centerline). With this configuration, the article may be placed in the desired middle or lowermost part of the undergarment&#39;s crotch region with the wing portions being secured closer to the front waist region of the undergarment. The wing portions may be thought of as forwardly biased on the article. This configuration offers substantial benefits. For example, the wings are attached to the undergarment or to each other at a wider part of the crotch region, thus providing a more secure attachment. Also, the location of the wings provides a visual indication to the wearer of the correct orientation of the article for use. The asymmetric shape also allows for variable fastening or fold angles of the wing portions with respect to the lateral sides of the article while retaining the overlap regions at the forward part of the article. For example, the fold lines may be angled away from the lateral sides of the pad from a forward most point of the fold lines to a rearward most point. In alternate embodiments, the fold lines may be angled towards the lateral sides of the pad from a forward most point of the fold lines to a rearward most point. This flexibility permits the user to easily customize the article to various styles and cuts of undergarments. In a particular embodiment, at a maximum angled position of the fold lines, the overlap regions are maintained at least partially overlapping and remain entirely on the forward side of the transverse centerline of the pad.  
      In one particular embodiment, the asymmetric wing portions have an outboard edge that tapers generally from the wing&#39;s respective overlap region towards the lateral side of the pad. For example, the overlap region may be disposed at a forward most position on the wing portion and be defined by a forward most edge that extends generally perpendicular to the lateral side of the pad such that the wing portion assumes an overall right triangle-type configuration. In an alternate embodiment, the forward most edge may extend at an angle from the lateral side of the pad towards the forward longitudinal end of the pad.  
      Aspects of the invention will described below in greater detail by reference to particular embodiments, examples of which are illustrated in the figures. 
    
    
     BRIEF DESCRIPTION OF THE FIGURES  
       FIG. 1  is a perspective and partial cut-away view of an absorbent article according to the invention.  
       FIG. 2  is a perspective view of the absorbent according to  FIG. 1  placed in an undergarment.  
       FIGS. 3A through 3D  are garment facing planar views of the absorbent article of  FIG. 1  as it would be attached at varying angular orientations on the crotch region of an undergarment.  
       FIG. 4  is a garment facing planar view of an absorbent article illustrating alternate wing portion configurations in phantom lines. 
    
    
     DETAILED DESCRIPTION  
      The invention will now be described in detail with reference to particular embodiments thereof. The embodiments are provided by way of explanation of the invention, and are not meant as a limitation of the invention. For example, features described or illustrated as part of one embodiment may be used with another embodiment to yield still a further embodiment. It is intended that the present invention include these and other modifications and variations as come within the scope and spirit of the invention.  
      Referring to the Figures, in which like numerals indicate like parts throughout the several views, embodiments of a disposable absorbent article  10  are depicted. For purposes of illustration only, the disposable absorbent article  10  is exemplified as a sanitary napkin. Typically, a sanitary napkin is worn by a female to absorb body fluids, such as menses, blood, urine and other body excrements discharged during a menstrual period. The term “disposable”, as used herein, means that the absorbent article is discarded after a single use and is not intended to be laundered for subsequent reuse.  
      One skilled in the art will readily understand the adaptability of the invention to other personal care and health care articles, such as, for example, panty liners, adult incontinence garments and the like that use a securement panel to position the article relative to a wearer&#39;s undergarment. It should thus be appreciated that the invention is in no way limited to sanitary napkins in particular, or to feminine care articles in general.  
      Referring to the figures in general, the absorbent article  10  according to the invention includes a primary pad component  18 . It should be appreciated that the shape of the pad component  18  depicted in the figures is for illustration purposes only, and that any shape or style of pad component  18  is within the scope and spirit of the invention. In use, the pad  18  is longitudinally oriented along a longitudinal centerline  21 , and has a transverse centerline  20  defined about midway between opposite longitudinal ends  24 ,  26 . The pad  18  has a generally liquid permeable top cover  28 , a generally liquid impermeable outer cover or “baffle”  30 , and an absorbent structure  32  disposed between the top cover  28  and baffle  30 . The top cover  28  and baffle  30  are sealed together at their peripheral edges utilizing known techniques, such as, for example, gluing, crimping, hot-sealing or the like, the sealed edges defining an overall sealed peripheral edge  33 . The pad  18  may take on various shapes, but will generally have opposite lateral sides  22  and longitudinal ends  24  and  26 , with the end  24  being the forward or front end of the pad  18 . In the illustrated embodiments, the pad  18  has a well-known elongated race-track shape with generally parallel sides  22 . In an alternate embodiment, the sides  22  may define a generally hourglass shape. Various other geometries of absorbent articles, including feminine care articles, are well known to those skilled in the art, and all such embodiments are within the scope and spirit of the invention.  
      The absorbent article  10 , particularly the pad  18 , is desirably provided with sufficient capacity to absorb and retain the intended amount and type of bodily exudate(s). The absorbent capacity is provided by the fluid retentive absorbent structure  32 . The absorbent structure  32  can be any structure or combination of components which are generally compressible, conformable, non-irritating to a wearer&#39;s skin, and capable of absorbing and retaining liquids and certain body wastes. For example, the structure  32  may include an absorbent web material of cellulosic fibers (e.g., wood pulp fibers), other natural fibers, synthetic fibers, woven or nonwoven sheets, scrim netting or other stabilizing structures, superabsorbent material, binder materials, surfactants, selected hydrophobic and hydrophilic materials, pigments, lotions, odor control agents or the like, as well as combinations thereof. In a particular embodiment, the absorbent web material is a matrix of cellulosic fluff, and may also include superabsorbent hydrogel-forming particles. The cellulosic fluff may comprise a blend of wood pulp fluff. One preferred type of fluff is identified with the trade designation NB 416, available from Weyerhaeuser Corp., and is a bleached, highly absorbent wood pulp containing primarily soft wood fibers. The absorbent materials may be formed into a web structure by employing various conventional methods and techniques. For example, the absorbent web may be formed with a dry-forming technique, an air forming technique, a wet-forming technique, a foam-forming technique, or the like, as well as combinations thereof. Methods and apparatus for carrying out such techniques are well known in the art.  
      The absorbent structure  32  can contain superabsorbent materials which are effective in retaining body fluids. As a general rule, the superabsorbent material is present in the absorbent web in an amount of from about 0 to about 90 weight percent based on total weight of the web. Superabsorbents have the ability to absorb a large amount of fluid in relation to their own weight. Typical superabsorbents used in absorbent articles, such as sanitary napkins, can absorb anywhere from 5 to 60 times their weight in body fluids. Superabsorbent materials are well known in the art and can be selected from natural, synthetic, and modified natural polymers and materials.  
      The absorbent web material may also be a coform material. The term “coform material” generally refers to composite materials comprising a mixture or stabilized matrix of thermoplastic fibers and a second non-thermoplastic material. Some examples of such coform materials are disclosed in U.S. Pat. No. 4,100,324 to Anderson, et al.; U.S. Pat. No. 5,284,703 to Everhart, et al.; and U.S. Pat. No. 5,350,624 to Georger, et al.; which are incorporated herein in their entirety by reference thereto for all purposes.  
      The absorbent web material utilized in the absorbent structure  32  is also selected so that the individual absorbent structure possesses a particular individual total absorbency depending on the intended article of use. For example, for infant care products, the total absorbency can be within the range of about 200-900 grams of 0.9 wt % saline, and can typically be about 500 g of saline. For adult care products, the total absorbency can be within the range of about 400-2000 grams of saline, and can typically be about 1300 g of saline. For feminine care products, the total absorbency can be within the range of about 7-50 grams of menstrual fluid, and can typically be within the range of about 30-40 g of menstrual fluid.  
      The absorbent structure  32  may be a multi-component and may include, for example, an intake layer or transfer delay layer in combination with the underlying absorbent web. Such configurations are well known to those skilled in the art.  
      The fluid permeable top cover  28  has an outwardly facing surface that may contact the body of the wearer and receive bodily exudate(s). The top cover  28  desirably is made of a material which is flexible and non-irritating to the wearer. As used herein, the term “flexible” is intended to refer to materials which are compliant and readily conform to the bodily surface(s) with which such materials are in contact, or materials which respond by easily deforming in the presence of external forces.  
      The top cover  28  is provided for comfort and conformability and functions to direct bodily exudate(s) away from the body, through the top cover  28  and toward the absorbent structure  32 . The top cover  28  should retain little or no liquid in its structure so that the cover provides a relatively comfortable and non-irritating surface next to the tissues within the vestibule of a female wearer. The top cover  28  can be constructed of any woven or nonwoven material which is easily penetrated by bodily fluids which contact the surface of the cover. Examples of suitable cover materials include rayon, bonded carded webs of polyester, polypropylene, polyethylene, nylon, or other heat-bondable fibers, polyolefins, such as copolymers of polypropylene and polyethylene, linear low-density polyethylene, and aliphatic esters such as polylactic acid. Finely perforated film webs and net material can also be used. The cover may be apertured to increase its fluid intake capacity. A specific example of a suitable cover material is a bonded carded web made of polypropylene and polyethylene such as that used as cover stock for KOTEX® pantiliners and obtainable from Sandler Corporation, Germany. Other examples of suitable materials are composite materials of polymer and nonwoven fabric materials. The composite materials are typically in the form of integral sheets generally formed by the extrusion of a polymer onto a web of spunbonded material. The fluid permeable cover  28  can also contain a plurality of apertures formed therein which are intended to increase the rate at which bodily fluid(s) can penetrate through the cover and into the absorbent structure  32 .  
      The top cover  28  may also be embossed with any desired embossing pattern to define embossed channels. Embossing techniques are well known to those skilled in the art. An embossing pattern not only creates an aesthetically pleasing surface, the channels facilitate intake of menses fluid. Menses will tend to flow along the densified edges of the channels rather than pool on contact points of the top cover  28 .  
      The top cover  28  can be maintained in secured relation with the absorbent structure  32  by bonding all or a portion of the adjacent surfaces to one another. A variety of bonding methods known to one of skill in the art can be utilized to achieve any such secured relationship. Examples of such methods include, but are not limited to, the application of adhesives in a variety of patterns between the two adjoining surfaces, entangling at least portions of the adjacent surface of the absorbent with portions of the adjacent surface of the cover, or fusing at least portions of the adjacent surface of the cover to portions of the adjacent surface of the absorbent.  
      The baffle  30  may be any one of a number of suitable liquid impermeable materials known in the art for use as outer covers or baffles in absorbent articles. Preferably, the baffle  30  will permit the passage of air and moisture vapor out of the pad  18  while blocking the passage of body fluids. A suitable material is a micro-embossed polymeric film, such as polyethylene or polypropylene, having a thickness of about 0.025 to 0.13 millimeters. Bicomponent films can also be used, as well as woven and nonwoven fabrics which have been treated to render them liquid impermeable. A specific example of a baffle material is a polyethylene film such as that used in KOTEX® pantiliners and obtainable from Pliant Corporation, Schaumburg, Ill., USA. The cover can be maintained in secured relation with the absorbent structure  32  by bonding all or a portion of the adjacent surfaces to one another. A variety of bonding methods known to one of skill in the art can be utilized to achieve any such secured relation. Examples of such methods include, but are not limited to, ultrasonic bonding, thermal bonding, or the application of adhesive materials in a variety of patterns between the two adjoining surfaces.  
      Referring to the figures in general, the article  10  includes wing portions  34  that extend laterally outward from the lateral sides  22  of the pad  18 . The wing portions  34  can take on various shapes and dimensions to achieve their function of extending around the crotch region of a wearer&#39;s undergarment. Referring to  FIG. 2 , for example, the article  10  of  FIG. 1  is illustrated attached to the crotch region  14  of a typical undergarment  12  to aid in securing the article  10  to the undergarment, as is generally understood by those skilled in the art. The area of the undergarment  12  designated as  16  is understood to be the front region of the undergarment. The wing portions  34  may be extensions of a single unitary structure attached to the baffle  30  with opposite laterally extending flaps that define the wing portions  34 . In an alternate embodiment, each wing portion  34  may be a separate flap or panel attached to the baffle  30 . In still another embodiment, the wing portions  34  may be defined by extensions of the baffle  30 .  
      The wing portions  34  may be formed of the same material as the baffle  30 . However, liquid impermeability and breathability are generally not concerns with the wing portions  34  and, thus, a different less expensive material may also be used. It should be appreciated that the type of wing material is not a limiting feature of the invention, and any suitable material may be used in this regard.  
      Referring to  FIG. 1 , the wing portions  34  have laterally outboard regions  38  that overlap when the wings  34  are folded around the crotch region  14  of the wearer&#39;s undergarment  12 , as illustrated in  FIG. 2 . For this purpose, an attachment mechanism is provided to secure the overlap regions  38  to each other or to the garment material. The attachment mechanism may be any conventional device, such as an adhesive patch or strip that may be covered by a peel strip prior to use. The adhesive patch may have any shape, surface area, etc. The dashed region  44  in the figures is meant to identify the location or placement of any suitable attachment mechanism, and not to limit the size, shape, or type of mechanism. For placement of the article  10 , the wearer simply peels the protective strip from the adhesive patch, places the article  10  in the crotch region  14  of the undergarment  12 , folds the wing portions  34  around the crotch region  14 , and presses the overlap regions  38  together such that the regions  38  attach to each other. In an alternate embodiment, or in addition to an adhesive strip, the attachment mechanism on the wing portions may include a mechanical fastener, such as a hook-and-loop fastener. For example, the patch  44  may be a patch of hook material that fastens to a loop-like material used to form the wing portions  34 , such as a non-woven material. Alternately, a hook material may be placed on one or both of the wing portions  34  such that the wings attach directly to the undergarment material. Examples of hook-and-loop fastening systems and components are described in U.S. Pat. No. 5,019,073 issued May 28, 1991 to T. Roessler et al., the entire disclosure of which is hereby incorporated by reference in a manner that is consistent herewith. Other examples of hook-and-loop fastening systems are described in U.S. patent application Ser. No. 366,080 entitled HIGH-PEEL TAB FASTENER, filed Dec. 28, 1994 by G. Zehner et al. which corresponds to U.S. Pat. No. 5,605,735; and U.S. patent application Ser. No. 421,640 entitled MULTI-ATTACHMENT FASTENING SYSTEM, filed Apr. 13, 1995 by P. VanGompel et al.; the entire disclosures of which are hereby incorporated by reference in a manner that is consistent herewith. Examples of fastening tabs constructed with a carrier layer are described in U.S. patent application Ser. No. 08/603,477 of A. Long et al., entitled MECHANICAL FASTENING SYSTEM WITH GRIP TAB and filed Mar. 6, 1996 which corresponds to U.S. Pat. No. 5,624,429 which issued Apr. 29, 1997, the entire disclosure of which is hereby incorporated by reference in a manner which is consistent herewith. It should be appreciated that various attachment device configurations are within the scope and spirit of the invention.  
      The wing portions  34  extend longitudinally along both sides of a transverse centerline  20  of the pad  18 , as seen particularly in  FIGS. 1 and 4 . In a particular embodiment, the wing portions  34  extend along a substantial portion of the lateral sides  22  of the pad  18 , for example along about two-thirds of the length of the sides  22 , and may extend an equal distance on each side of the centerline  20 . The wing portions  34  have an asymmetric shape with the overlap regions  38  disposed forward of the transverse centerline  20  towards the forward longitudinal end  24  of the pad  18 . With this configuration, referring to  FIG. 2 , the article  10  may be placed in the desired middle or lowermost part of the undergarment&#39;s crotch region  14  with the overlap regions  38  secured closer to a front waist region  16  of the undergarment  12 . As described above, the asymmetric configuration of the wing portions  34  with the overlap regions  38  disposed entirely on the forward end side of the transverse centerline  20  offers substantial benefits. For example, the wing portions  34  may be attached to the undergarment  12  or to each other at a wider part of the crotch region  14 , thus providing a more secure attachment of the article. Also, the location of the wings  34  provides a visual indication to the wearer of the correct orientation of the article for use.  
      The asymmetric shape of the wing portions  34  may take on various shapes. In the illustrated embodiment, the wing portions have a forward most laterally extending edge  40  and a generally tapering outboard edge  36 . The edge  36  tapers from the overlap region  38  towards the lateral side  22  of the pad  18 . The edge  36  may taper at a constant angle, a variable angle, step-wise, and so forth. This unique configuration also allows for variable fastening or fold angles of the wing portions  34  with respect to the lateral sides  22  of the pad  18 , as seen in  FIGS. 3A through 3D . In  FIG. 3A , it can be seen that the wing portions  34  are folded such that the fold lines  42  are generally parallel to the pad lateral sides  22  and the forward edge  40  is generally perpendicular to the sides  22 . This fold pattern may be desired if the undergarment has a fairly wide and constant width crotch region  14 , as in the undergarment  12  shown in  FIG. 2 .  FIGS. 3B through 3D  shown embodiments wherein the fold lines  42  are increasingly angled away from the lateral sides  22  such that the forward edges  40  are drawn towards the center of the pad  18  and the rearward portions of the wings flare outwardly. These different fold patterns may be desired for various styles and configurations of undergarments.  FIG. 3D  depicts a generally maximum angle of the fold lines  42 . Even in this configuration, the overlap regions  38  are at least partially overlapping and disposed forward of a transverse centerline  20  ( FIG. 1 ) of the pad  18 .  
      It should also be appreciated that the overlap regions  38  may be configured such that the wing portions  34  are folded along fold lines  42  that angle towards the lateral sides  22  from the front of the pad to the back of the pad. In this embodiment, the frontward portions of the wings would flare outwardly, generally opposite to the embodiment of  FIGS. 3A-3D . To accommodate this fold pattern, the overlap regions  28  would need an lateral extension and shape so as to be drawn towards the front of the pad in the various fold patterns, and not towards the center of the pad as with the embodiments of  FIGS. 3A-3D .  
       FIG. 4  illustrates other various embodiments of the wing portions  34 . For example, with one embodiment, the wing portions  34  have forward most edges  40   a  that are generally perpendicular to the pad lateral sides  22 , and outboard tapered edges  36   a  such that the wing portion assumes an overall right triangle-type configuration. In an alternate embodiment, the wing portions  34  have outboard edges  36   b  and forward most edges  40   b  extending laterally from the sides  22  at an angle towards the forward end  24 . In still another embodiment, the wing portions  34  extend laterally to a lesser extent and have angled forward most edges  40   c  and outboard edges  36   c . In the final illustrated embodiment, the wing portions  34  have angled forward most edges  40   d  that extend longitudinally past the end  24  of the pad  18 .  
      It should be appreciated by those skilled in the art that various modifications and variations can be made to the embodiments of the absorbent article described herein without departing from the scope and spirit of the invention as set forth in the appended claims and equivalents thereof.