MXPA99005475A - Flexible absorbent article having increased stiffness before use - Google Patents

Abstract

A disposable absorbent article for wearing in an undergarment, such as a sanitary napkin, pantiliner, or incontinence pad is described. The absorbent article comprises a topsheet, a backsheet, an absorbent core, and a stiffening feature. The stiffening feature places the absorbent article in an initially stiffened during placement of the article in an undergarment. After the article is subjected to the forces exerted by the body of the wearer, the stiffening feature no longer provides an increased initial stiffness and the article becomes more flexible.

Description

FLEXIBLE ABSORBENT ARTICLE THAT HAS INCREASED RIGIDITY BEFORE USING FIELD OF THE INVENTION The present invention relates generally to absorbent articles such as sanitary napkins, pantiliners and incontinence pads. More particularly, the present invention relates to sanitary napkins that are relatively stiff during the placement of the sanitary napkin in an undergarment, and as the panty is pulled inward towards the position, but which exhibits levels of flexibility and draping. elevated during use.

BACKGROUND OF THE INVENTION Absorbent articles such as sanitary napkins, pantiliners and incontinence pads are devices that are typically used in the crotch region of an undergarment. These devices are designed to absorb and retain fluid and other discharges from the human body, and to prevent staining of body and clothing. Sanitary napkins are a type of absorbent article worn by women within a pair of panties, which is normally placed between the legs of the wearer, adjacent to the perineal area of the body. It has been found desirable to build absorbent articles that are thin, stretchable, soft and highly drapable. Such a flexible, extensible absorbent article is disclosed in PCT application publication No. 95/20931, published on August 10, 1995. These high levels of flexibility and draping provide comfortable products with low usage knowledge. To handle these articles more effectively, however, superior stiffness and inflexibility are often required to prevent the article from retracting as the article is placed on the undergarment and as the undergarment is pulled toward the position in the long run. The apparent contradiction of providing an absorbent article that is both flexible and rigid can be overcome by recognizing that needs for rigidity and flexibility are not simultaneously required, but are needs that are separated by time. Many of the current absorbent articles, particularly those with absorbent air filter cores, are soft and flexible when they are first placed in an undergarment, but become stiffer when wet. These characteristics of flexible and then rigid are seen in absorbent articles with other types of cores as well. U.S. Patent No. 5,374,260 issued to Lemay et al. On December 20, 1994, discloses a sanitary towel with a moss peat core which is flexible, then more rigid when moisture is absorbed. It is also known in the art to apply resilient structures to absorbent articles to impart a general rescilence to the article or separate from the article. The patent of the United States No.

No. 5,098,422 issued to Davis et al. On March 24, 1992, describes a sanitary towel retaining the shape. This restraint of shape retention, however, remains throughout the life of the sanitary napkin. Therefore, there is a need for a disposable absorbent article that is relatively rigid when an undergarment is handled and applied, but which becomes more flexible when worn. This absorbent article has the advantage of being easy to handle and apply an undergarment without the article folding or adhering itself while also offering greater comfort and low knowledge of use during subsequent use. Therefore, it is an object of the present invention to provide an absorbent article, such as a sanitary napkin which is relatively rigid when an undergarment is handled and applied, but which becomes more flexible when worn. This and other objects of the present invention will be more readily apparent when considered with reference to the following description and when taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE INVENTION The present invention provides an absorbent article, such as a sanitary napkin, pantyhose or incontinence pad. More particular < The present invention is directed to a sanitary napkin which is generally rigid when it is handled and applied to an undergarment, but which becomes more flexible when worn. The sanitary napkin comprises a liquid-permeable topsheet, a liquid-impermeable backsheet attached to the topsheet, and an absorbent core positioned between the topsheet and the backsheet. The sanitary napkin is also provided with a stiffness characteristic that imparts an initial stiffness to the sanitary napkin. The stiffness characteristic may comprise one or more stiffening members or the stiffness characteristic may be provided directly by the structure of one or more of the aforementioned elements (i.e., the topsheet, the backsheet, and the absorbent core) . The stiffness characteristic of the present invention provides the sanitary napkin with a degree of rigidity when an undergarment is handled and applied, but not when the sanitary napkin is used. The sanitary napkin is preferably generally flexible when used. In a particularly preferred embodiment, the sanitary napkin is also very thin, extensible, soft and highly drapable when used in such a way that it is more similar to the fabric and less similar to plastic (like many of the current sanitary napkins). The main body portion of this preferred sanitary napkin extends with the wearer's undergarments and provides the sustained coverage of a larger portion of the wearer's panties. In a preferred embodiment, the difference in stiffness between the handling of the sanitary napkin and the use of the sanitary napkin is achieved through the use of brittle strips of material which are torn apart when subjected to the normal forces associated with the sanitary napkin. Use of the article (for example, when the user sits or walks.

These strips are preferably located between the backsheet and the absorbent core. In a preferred alternate embodiment, the characteristic -1e atiesaroienic may comprise a tube-shaped member constructed of a layer of tissue wrapped in a polypropylene layer. The polypropylene layer is preferably melted in the tissue layer to provide the required initial stiffness. The tube structure crushes when the user sits down, allowing so? that the sanitary towel assumes a generally flexible state. In still a further preferred embodiment, the stiffening characteristic comprises zones of stiffness that occupy at least a portion of the sanitary napkin. The stiffening zones can be reinforced locations on the top sheet, the back sheet, the core or some combination of these. The stiffening zone may comprise a layer of hardened material such as the hardened tissue layer by melting a layer of polypropylene therein. This hardened layer is then bonded to the backsheet, to the topsheet, or to the absorbent core of the sanitary napkin. The increased rigidity provided by the zones of stiffness is lost once the sanitary napkin is subjected to normal forces of use, thus allowing the sanitary napkin to assume a generally flexible state. The sanitary napkin can, and preferably should, also comprise several additional components and / or features. For example, the sanitary napkin preferably comprises a pair of lateral extensions that extend laterally outwardly from the main body portion of the sanitary napkin.

BRIEF DESCRIPTION OF THE DRAWINGS Although the description concludes with the claims pointing out in a particular manner, and claiming differently from the present invention, the invention will be better understood from the following description taken in combination with the accompanying drawings in which similar designations are used to describe the invention. designate substantially identical elements, and in which: Figure 1 is a plan view of a preferred embodiment of the sanitary napkin of the present invention; Figure 2 is a sectional view taken along line 2-2 of the sanitary napkin shown in Figure 1. Figure 3 is a bottom plan view of the sanitary napkin shown in Figure 1, with the paper of detachment removed from the adhesive on the backsheet. Figure 4 is a simplified plan view showing the extension capacity of a sanitary napkin in a more conventional manner, which has extensible components. Figure 5 is a top plan view of a preferred alternative embodiment of sanitary napkins of the present invention. Figure 6 is a sectional view taken along line 6-6 of the sanitary napkin shown in Figure 5. Figure 6A is a sectional view similar to Figure 6, but showing a variant in the preferred embodiment shown in Figure 6. Figure 7 is a simplified top plan view of a preferred alternative embodiment of the sanitary napkin of the present invention. Figure 8 is a simplified top plan view of a preferred additional embodiment of the sanitary napkin of the present invention. Figure 9 is a simplified top plan view of a further embodiment of the sanitary napkin of the present invention. Figure 10 is a simplified top plan view of a variation of the embodiment shown in Figure 9. Figure 11 is a simplified top plan view of a further embodiment of the sanitary napkin of the present invention. Figure 12 is a simplified top plan view of an alternative embodiment of the sanitary napkin of the present invention.

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to absorbent articles having an initially hardened condition during the placement of the article in an undergarment and as the undergarment is pulled toward the position, but which is more flexible during use. The term "absorbent article," as used herein, refers to articles that absorb and contain body exudates. More specifically, the term refers to articles that are placed against or close to the user's body to absorb and contain the various exudates discharged from the body. The term "absorbent article" is intended to include sanitary napkins, pantiliners, and incontinence pads (and other articles used in the crotch region of a garment). The term "disposable" refers to articles that are intended to be discarded after a single use and preferably recycled, composted, or otherwise discarded in an environmentally compatible manner. That is, these are not intended to be washed or restored or otherwise reused as an absorbent article. Figures 1 to 3 show a preferred embodiment of a disposable absorbent article of the present invention. In the preferred embodiment illustrated, the absorbent article is a designated sanitary napkin 20. The term "sanitary napkin" as used herein, refers to an article that is worn by women adjacent to the pudendal region that is intended to absorb and contain the various exudates that are discharged from 'body (for example, blood, menstruation and urine). However, it should be understood that the present invention is also applicable to other feminine hygiene pads or catamenial pads such as panty liners, or other absorbent articles such as incontinence pads and the like. The sanitary napkin has two surfaces, a surface that is in contact with the body or "body surface" 20A permeable to liquid and a garment surface 20B impervious to liquid. The sanitary napkin 20 is shown in Figure 1 as seen from its body surface 20A. The body surface 20A is intended to be used adjacent to the wearer's body. The garment surface 20B of the sanitary napkin 20 shown in Figure 2), is on the opposite side and is intended to be placed adjacent to the wearer's undergarments, when the sanitary napkin 20 is used. The sanitary napkin 20 has two center lines, a main longitudinal center line L and a main transverse center line T. The term "longitudinal" as used herein, refers to a line, axis or direction in the plane of the sanitary napkin 20 which is generally aligned with ( that is, approximately parallel to), a vertical plane that divides a user standing in left and right body halves when using the sanitary napkin 20. The terms "transverse" or "lateral", used herein are interchangeable, and refer to a line, axis or direction generally perpendicular to the longitudinal direction. The sanitary napkin 20 has a longitudinal dimension running in the general direction of the main longitudinal centerline L, and a transverse dimension (typically shorter), which runs in the general direction of the main transverse centerline T. Figure 1 shows that the sanitary napkin 20 has a main body portion 21 with two separate longitudinal edges 22, two transverse edges or spaced apart end edges (or "ends") 24, and four corners 27, which together form the periphery 26 of the portion of main body 21 of sanitary napkin 20. The portion of? ef- ~. main 21 also has two end regions, which are designated first end region 28 and second end region 30. A central region 32 is disposed between end regions 28 and 30. End regions 28 and 30 extend outwardly from the edges of the end regions. the central region 32 to about 1/8 to 1/3 of the length of the main body portion. A detailed description of a central region and two end regions for a sanitary napkin is contained in U.S. Pat. No. 4, 690,680 issued to Higgins on September 1, 1987. The sanitary napkin 20 (or its main body portion can be of any thickness, including relatively thick, of intermediate thickness, relatively thin or even very thin, the modality of the sanitary napkin 20 shown in Figures 1 to 3 of the drawings is intended to be an example of a relatively thin sanitary napkin (having a gauge less than or equal to about 5 mm, more preferably less than or equal to about 4 mm), and preferably it is an "ultra-thin" sanitary napkin It should be understood, however, that when these figures are observed the numbers of the layers of the material shown cause the sanitary napkin 20 to appear much thicker than it actually is. ultrathin ", as described in U.S. Patent Nos. 4,950,264 and 5,009,653 issued to Osborn, preferably has a caliper of less than about 3 mm. The thin sanitary towel 20 shown preferably should also be relatively flexible, so that it is comfortable for the wearer. Figure 2 shows the individual components of the sanitary napkin 20 of the present invention. The sanitary napkin shown in Figure 2 generally comprises at least one liquid-permeable upper sheet 38, a liquid-impermeable backsheet 40 and an absorbent core 42. The sanitary napkin 20 is also provided with at least one stiffening feature 44. In the preferred embodiment shown in Fig. 2, the stiffening feature 44 comprises a pair of brittle strip stiffening members 46. The absorbent core 42 and preferably the brittle strip stiffening members 46 are placed between the topsheet 38 and the backsheet 40. More preferably, the brittle strips 46 are placed between the backsheet 40 and the absorbent core 42 or within the core absorbent 42, but brittle strips 46 may also be placed between upper sheet 38 and absorbent core 42, or, less preferably on the garment facing side of back sheet 40B. The components of the sanitary napkin 20 may comprise suitable materials described in the patents incorporated by reference herein. The sanitary napkin 20 can, but does not need to be composed of extendable components. Preferably, however, the sanitary napkin 20 is composed of one or more extensible components and more preferably is composed of all of the extensible components and thus has a general spreadability during use. Suitable extensible materials for sanitary napkin components 20 are disclosed in U.S. Patent Application Serial No. 07 / 915,133 filed July 23, 1992, in the name of Osborn et al. (PCT Publication No. WO) 93/01785 published on February 4, 1993), now pending in the form of application for continuation granted Serial No. 08 / 503,895, filed July 18, 1995; in U.S. Patent Application Serial No. 07 / 915,284 filed July 23, 1992, in the name of Osborn et al. (PCT Publication No. 93/01786 published February 4, 1993), now pending in the divisional application form granted Series No. 08 / s472,156 and 08 / 476,238 both filed on June 7, 1995; and United States Patent Application No. 08 / 472,156 and 008 / 476,238 both filed on June 7, 1995; and U.S. Patent Application Serial No. 08 / 192,240 filed February 4, 1994 in the name of Osborn et al., (PCT Publication No. WO / 95/20931). The stiffening characteristic or features 44 may also, but do not need to be extensible. The characteristics of the extension capacity of a preferred sanitary napkin 20 will now be discussed in greater detail. The extension capacity of sanitary napkins 20 is shown in a simplified manner in Figure 4, the term "spreadable", as used herein, refers to articles that can increase in at least one of their dimensions in the plane xy. The xy plane is a plane generally parallel to the surface of the sanitary napkin 20. The term "spreadable" includes articles that are stretchable and elastically stretchable (defined below), the sanitary napkin 20 shown in Figures 1 to 3 is preferably extensible during the use of both length and width. In its most preferred embodiments, the sanitary napkin is extendable in all directions in the x-y plane. The sanitary napkin 20, in other embodiments, however, may be generally non-extensible, only extendable in one of these directions or extendable in some direction between the longitudinal and transverse directions. Preferably, the sanitary napkin 20 is extensible at least in the longitudinal direction. The sanitary napkin may in some preferred embodiments, in addition to being extensible also be stretchable. The term "stretchable," as used herein, refers to articles that are extensible when stretch forces are applied to the article and offer some resistance to stretching. More preferably still, the sanitary napkin 20 can be elastically stretchable. The terms "elastically stretchable" and "elastically extensible" are intended to be synonymous. These terms, as used herein, mean that when the stretching forces are removed, the sanitary napkin will tend to return to its non-stretched or unstretched or "original" dimensions. However, the sanitary napkin 20 does not need to return completely to its unstretched dimensions. This can, as shown in Figure 4, return to the relaxed dimensions (such as LR and Wk) between unstretched dimensions and the extended (or stretched) dimensions Ls and Ws, making the sanitary towel elastically stretchable during use. , the undesirable tendency of the sanitary napkin to be shirred longitudinally inwardly (i.e., ablate longitudinally and become misaligned) in the wearer's panties when the forces tending to stretch the sanitary napkin such as when the panties are removed is removed. of the user contract.The modality of the sanitary towel 20 preferred shown in Figures 1 to 3, is preferably extensible during use, in the amounts described in the previously discussed U.S. patent application Serial No. 07 / 915,133, (PCT Publication No. WO 93 // 01785), United States patent application. No. 07 / 915,284 (PCT Publication No. WO 93/01786), United States Patent Application No. 08 / 192,240 (PCT Publication No. WO 95/20931). To summarize the same, the sanitary napkin 20 is preferably capable of extending from about 5% to less than about 50%, more preferably between about 10% and about 40% under the forces associated with the use of the sanitary napkin in a pair of panties. Preferably, the sanitary napkin is capable of this extension under forces of between about 50 to 100 grams to about 1000 to 1500 grams, more preferably under forces of between about 800 grams. The sanitary napkin 20 of the present invention can also be provided with any of the other characteristics of the sanitary napkins described in the prior publications including, a structure that provides a "strength wall", to prevent elongation that exceeds a certain amount without the Substantial increase in the amount of force applied to the sanitary napkin. Furthermore, in some especially preferred embodiments described in greater detail herein, various components of the sanitary napkin 20 are capable of smaller extension amounts under forces at the lower end of the very broad scale set above (e.g., forces on the scale of approximately 100 to 200 grams). For example, in these embodiments, the sanitary napkin 20 is preferably capable of extending to about 2.5%, more preferably about 3% to 100 grams of force and about 5%, more preferably about 7.5% to 200 grams of force. In absorbent articles with smaller amounts of extensibility under low forces, the force wall can also occur at low elongations at about 5% elongation, but can occur at elongations of up to about 50% elongation. Furthermore, in the embodiments of the sanitary napkin (or other absorbent article) of the present invention that is extensible, the sanitary napkin 20 is preferably extensible in at least the same amounts and under the same forces as the wearer's panties (u other undergarments), in such a way that the panties control the extension capacity of the sanitary napkin during use). In other words, the sanitary napkin preferably has a modulus of elasticity that is close to, and preferably less than or equal to that of the undergarment, in which it is placed, for example, if the undergarment requires a force to extend. at about 5% (or about 10%), the sanitary napkin (ie, the main body portion thereof preferably requires a force to extend the same amount that is less than or equal to about 1.2 times, more preferably less than or equal to approximately 1 time the force required to extend the undergarment.The force required to extend the crotch region of a typical American woman's panties in the transverse direction (at the narrowest point thereof), is approximately 135 g / cm The force required to extend the back panel portions of this panty where the second end region of the sanitary napkin could lie in the longitudinal direction it is approximately 165 g / cm. A typical force for lengthening the elastic of the panties of a cotton swab in North America is approximately 135 g / cm. The elastic forces of other types of panties or undergarments may be a little higher. The sanitary towel 20 (or other absorbent article) of the present invention, but does not need to exhibit the extension capacity, described above, before the moment the sanitary towel is placed inside the wearer's undergarment, adjacent to the pudendal region of the wearer's body. While the sanitary napkin is being placed on an undergarment and preferably as the undergarment retaining the sanitary napkin is pulling toward the position as well, the sanitary napkin exhibits a greater rigidity than this during use by virtue of the inclusion of the sanitary napkin. the stiffening characteristic (s) 44. The stiffening characteristic (s) 44, imparts a temporary stiffness to the sanitary napkin 20, which exhibits its flexibility and can, if desired for ease of handling, also inhibit its ability to extend prior to use. The absorbent article according to the present invention will remain in its initially hardened condition and can remain substantially non-stretchable and non-stretchable until it is first subjected to forces exceeding a predetermined "initial stiffness threshold". The initial stiffness threshold may vary for the different embodiments of the present invention in all embodiments, the initial stiffness threshold must be chosen to be greater than the scale of expected forces exerted on the absorbent article during the packed, boarding handling and placement in an undergarment. Also, the strength levels represented by the initial stiffness threshold must be lower than those forces typically exerted on the absorbent article by the user's body (for example, as soon as he sits, walks, etc.). that the item is inside an undergarment. Ideally, the initial stiffness threshold should not be exceeded until the article is placed adjacent to the user's body but must be exceeded after first some user steps, when the user first sits, etc). the appropriate initial stiffness threshold for the various embodiments of the present invention is selected with these objectives in mind. It is not necessary that the stiffening characteristic or features 44 of the present invention impart this initial temporary stiffness to the entire sanitary napkin. The objects of the invention can be achieved by imparting an initial stiffness to only a part or parts of the absorbent article. It is also acceptable that the initial stiffness threshold be exceeded in localized parts of the article during packing. For example, a sanitary napkin of the present invention can be folded or bent three times during packaging along the predetermined fold lines. In such a scenario, the initial stiffness threshold of the sanitary napkin, as described above, may be exceeded along these fold lines. An absorbent article according to the present invention, intended to be folded during packing, can be constructed with a stiffening feature, which, before bending, acts on the parts of the article, which cross these fold lines. In such a scenario, the stiffening characteristic may cease to provide an increased initial stiffness in the localized bending area when the article is folded during packing. Alternatively, the article can be constructed with two or more independent areas of initial stiffness that do not cross the fold lines, thus allowing the article to be bent without exceeding the initial stiffness threshold in any of the areas imparted with stiffness initial described. The preferred sanitary napkin embodiment 20 may have an initial stiffness exceeding that of the sanitary napkin described in U.S. Patent No. 5,460,623 issued to Emenaker et al. On October 24, 1995. Once the towel is placed sanitary 20 (or other absorbent article), and the wearer's body has exerted forces greater than the initial stiffness threshold on the sanitary napkin, the stiffening characteristic or features 44 will substantially cease to provide any increased stiffness or inflexibility to the sanitary napkin. That is, even when subsequently exposed to forces below the initial stiffness threshold (after the initial exposure in the early stages of use), the sanitary napkin 20 will respond in a manner characteristic of a generally flexible and preferably extensible absorbent article and stretchable above). The flexibility exhibited by Sanitary Towel 20 after it has been. Exceeded the initial stiffness threshold, it can be approximated to that of the sanitary napkin described in United States Patent Application No. 08 / 192,240 filed on February 4, 1994 in the name of Osborn et al. (PCT Publication No. WO 95/20931). The individual components that may be suitable for the various embodiments of the sanitary napkin 20 of the present invention will now be observed in greater detail with references to Figures 1 to 3. The topsheet 38 comprises a first liquid-permeable component. When the sanitary napkin 20 is in use the upper sheet 38 is in close proximity to the user's skin, the upper sheet 38 may be extensible or non-extensible depending on the type of absorbent article used therewith. The topsheet 38 used in the embodiment shown in Figures 1 to 3, is preferably extensible, more preferably elastically extensible, and is user-friendly, soft-feeling and non-irritating to the wearer's skin as possible. The topsheet 38 must also exhibit good penetration and a reduced tendency to rewet, allowing the bodily discharges to penetrate rapidly and flow to the core 42, but not allowing the discharges to flow back through the topsheet 38 towards the skin. of the user. A suitable top sheet 38 can be manufactured from a wide range of materials, including, but not limited to, woven materials and fabrics, thermoplastic films formed with openings, plastic films with openings and thermoplastic liners. Suitable nonwovens and fabrics may be composed of natural fibers (eg, wood or cotton fibers), modified synthetic or natural fibers (e.g., polymer fibers such as polyester, polypropylene and polyethylene fibers), or alcohol polyvinyl, resins based on starch, polyurethanes, cellulose esters, nylon and rayon fibers), or from a combination of natural and synthetic fibers. When the upper sheet 38 comprises a nonwoven web, the web can be spun bonded, carded, wet laid, melt blown, hydroentangled, combinations of the above, or the like. Films with openings are generally preferred for the topsheet 38 because they are permeable to liquids, and if properly perforated, have a reduced tendency to allow liquids to pass through and rewet the user's skin. , films with suitable openings are described in U.S. Patent No. 3,929,135 issued to Thomspon on December 30, 1975; U.S. Patent No. 4,324,426 issued to Mullane et al. on April 13, 1982; U.S. Patent No. 4,342,314 issued to Radel et al. on August 3, 1982; U.S. Patent No. 4,463,045 issued to Ahr et al. on July 31, 1984; U.S. Patent No. 5,006,394 issued to Baird on April 9, 1991. A particularly suitable top sheet 38 is made in accordance with U.S. Patent No. 4,342,314 issued to Radel et al. and to the U.S. Patent. No. 4,463,045 issued to Ahr et al. An upper sheet 38 made from the formed film with openings model X-3265 or model P1552 sold by Tredegar Corporation of Terre Haute, Indiana has been found to work well. The upper sheet 38 can be made extensible by performing a mechanical operation ta! like pleating, corrugated, or rolling with ring over e! material of the upper sheet to provide folds in the upper sheet 38 that are capable of opening when the upper sheet 38 is stretched. The term "ring rolling", as used herein, refers to a process of feeding the material of the upper sheet between a pair of internally grooved rollers, these processes can be performed on many of the upper sheet materials described above. In a preferred embodiment of the present invention, the topsheet 38 is made in accordance with U.S. Patent No. 4,463,045 and rolled with a ring to provide it with a degree of longitudinal extension capacity. This topsheet is described in U.S. Patent No. 5,366,783 issued to Curro et al. On November 22, 1994. Suitable processes for ring rolling or "precorrugado," are described in U.S. Pat. 4,107,364 issued to Sisson on August 15, 1978; in the patent of the United States No. 4,834,741 issued Sabee on May 30, 19889; in U.S. Patent No. 5,167,897 issued to Weber et al. on December 1, 1992; in U.S. Patent No. 5,156,793 issued to Buell et al. on October 20, 1992; and in U.S. Patent No. 5,143,679 issued to Weber on September 1, 1992. The fold lines in the corrugations of a ring-rolled top sheet are preferably oriented in the transverse direction such that the top sheet is longitudinally extensible. In other embodiments, the fold lines may run in the longitudinal direction, both in the longitudinal and transverse directions and / or in other directions. The top sheet will be extendable in the directions perpendicular to the fold lines. In the particularly preferred embodiments shown in Figures 1 to 3, the upper sheet 38 comprises a film with openings, such as that described in U.S. Patent No. 4,463,045, which is provided with a deformable network such that the upper sheet 38 exhibits an elastic-like behavior without additional elastic materials. A weft material with such a deformable network can be referred to herein as a "weft material with deformable openings" or, for brevity with a "deformable weft material", or simply as the "weft material". This type of material is also referred to herein as a film material in the form of structural elastic or "SELF" material. A suitable deformable apertured weft material is described in U.S. Patent No. 5,518,801 issued to Chappell et al. On May 21, 1996. A portion of the topsheet 38 shown in Figure 1 is shown as a material of deformable weft 60 (SELF material). The rest of the upper sheet 38 is not shown as SELF in order to more clearly show other characteristics of the sanitary napkin 20. In the preferred embodiments, the upper sheet 38 is made hydrophilic in such a way that liquids will transfer through the sheet 38 higher faster. This will decrease the likelihood that the body exudates will flow out of the topsheet instead of being drawn through the topsheet 38 and absorbed by the absorbent core 42. The topsheet 38 can be made hydrophilic by treating it with surfactants. Suitable methods of applying the surfactants are described in U.S. Patent Nos. 4,950,254 and 5,009,653 issued to Osborn (which include the incorporation of the surfactant into the polymeric material of a formed film topsheet) as well as the treatment of the surface of the underlying component of the top sheet with a surfactant. Furthermore, in the preferred embodiments, the inner surface 38B of the topsheet 38 is secured in contact relation with an underlying absorbent layer. This contacting ratio results in faster liquid penetration of the topsheet 38. The topsheet 38 can be maintained in a contact relationship with an underlying layer by attaching the topsheet to the underlying layer. However, it is not absolutely necessary to attach the surface of the upper sheet 38 to the surface of the underlying layer. The topsheet 38 can be maintained in contact with an underlying absorbent component, entangling the fibers of the underlying layer with the topsheet, by melting the topsheet 38 to an underlying absorbent layer by a plurality of discrete melt-singlons, or by any means known in the art. The absorbent core 42 is positioned between the topsheet 38 and the backsheet 40. The absorbent core 42 provides the means for absorbing exudates such as menses and other body fluids. The absorbent core 42 does not need to have an absorbent capacity much greater than that of the total amount of anticipated body fluids that are absorbed. The absorbent core 42 is preferably generally compressible, conformable and non-irritating to the wearer's skin. In the embodiments shown in Figures 3, the absorbent core 42 is preferably extensible. The absorbent core 42 however, it does not need to be extensible in all modalities to provide a benefit. For example, a relatively non-extensible core can be used in a mode in which the top sheet together with the underlying absorbent component (or integral absorbent component) is extensible and the top sheet and this component are not bonded to the core surface , so that they are able to separate from (or "uncouple" from) the core. The concept of decoupling (in general) is described in U.S. Patent No. 5,007,906 issued to Osborn on April 16, 1991. This embodiment is useful if the topsheet 38 is capable of extending independently of the absorbent core. 42 and any of the other underlying components that are relatively non-extensible. The absorbent core 42 may comprise any material used in the art for this purpose including natural materials and synthetic materials, non-limiting examples of these materials include materials such as ground wood pulp (which is generally referred to as an air filter) , like dß cell-- to crepari ^. hydrogel-forming polymeric gelling agents, and their creped or creped non-woven materials containing fibers composed of absorbent or superabsorbent polymers, crosslinked, modified cellulosic fibers (such as those described in U.S. Patent No. 5,217,445 issued to Young et al. others on June 8, 1993), capillary channel fibers (i.e., fibers having intrafiber capillary channels), such as those described in U.S. Patent No. 5,200,248 issued to Thompson et al. On April 6, 1993), absorbent foams such as those described in U.S. Patent No. 5,268,248 issued to DesMarais, and others on December 7, 1993), materials placed with thermally bonded air (such as those materials described in United States Patent Application No. 08 / 141,156 entitled "Catamenial absorbent structure having thermally bonded layers for improved handling of menstrual fluids and their use in catamenial pads having improved fit and comfort", presented on behalf of Richards and others on October 21, 1993), absorbent sponges, synthetic short fibers, polymer fibers, peat moss, or any equivalent material or combinations of materials. The polymeric gelling agents listed above are also referred to as "gelling absorbent materials (" AGM ") or" superabsorbent materials. "Polymeric gelling agents are those materials that, upon contact with liquids such as water or other liquids. These liquids are saturated with these liquids and thus form the hydrogels, in this way, the liquids discharged to the absorbent core 42 can be acquired and maintained by the polymeric gelling agent, thus providing the articles of the present with absorbent capacity. Increased and / or enhanced liquid retention performance The polymeric polymerization agent that is employed in the absorbent core 42 will generally comprise particles of a partially crosslinked partially neutralized hydrogenation polymer material substantially insoluble in water. polymeric gelling can be in many forms, including in the form of particles, flakes or fibers. In a preferred embodiment, the absorbent core 42 is a laminate. The laminate is composed of a layer of superabsorbent polymeric material, such as in the form of particles 41, disposed between two tissues placed with air, first and second layers of tissue. The first and second tissue layers provide containment of the superabsorbent polymeric material, improve the lateral capillary action of the exudates absorbed throughout the absorbent core 42 and provide a degree of absorbency. The tissue layers may be composed of a simple tissue web which is bent with the particles of the superabsorbent material 41 between them or two separate sheets of the same tissue (or different). A suitable laminate is a superabsorbent laminate known as WATER-LOCK L535 available from Grain Processing Corporation of Muscatine, Iowa (WATER LOCK registered trademark by Grain Processing Corporation). These superabsorbent laminates are described in U.S. Patent No. 4,467,012 issued to Pedersen et al. On August 21, 1984; U.S. Patent No. 4,260,443 issued to Lindsay et al. on April 7, 1981; U.S. Patent No. 4,578,068 issued to Kramer et al. on March 25, 1986; and U.S. Patent No. 5,460,623 issued to Emenaker et al. on October 24, 1995. The absorbent core materials described above can be made extensible in many different ways, including by cutting, by slitting them. Figure 1 shows an embodiment in which the upper sheet 38 is partially cut out and the absorbent core 42 is a laminate as described above, which is grooved or partially grooved with transverse grooves for the longitudinal extension capacity. The backsheet 40 prevents the exudates absorbed and contained in the absorbent core 42 from wetting the articles that are in contact with the sanitary towel 20 such as underpants, pajamas and undergarments. The topsheet 40 should be flexible and impervious to liquids (eg, menstruation and / or urine). The backsheet 40 may comprise a woven or non-woven material, polymeric films such as polyethylene or polypropylene thermoplastic films, or composite materials such as a woven, film-coated material. Preferably, the backsheet 40 is a thin plastic film, such as a polyethylene film having a thickness of about 0.012 mm to about 0.051 mm. Exemplary polyethylene films are manufactured by Clopay Corporation of Cincinnati, Ohio, under the designation P18-1401 and by Tredegar Film Products of Terre Haute, Indiana under the designation XP-39385. The backsheet 40 is preferably embossed and / or dull finished to provide a more fabric-like appearance. In addition, the backsheet 40 may allow the vapors to escape from the absorbent core 42 (ie, the backsheet 40 may be breathable), while still preventing the passage of the exudates through the backsheet 40. The subsequent flowable sheets and spreadable or biodegradable, they can also be used, for example, as with the pantiprotective devices described herein. Another suitable material for the backsheet is a nonwoven / film laminate described in U.S. Patent No. 5,007,906 issued to Osborn on April 16, 1991. The backsheet 40 can have the same extensibility characteristics as the top sheet 38. The back sheet 40 can be made extensible by forming it from a film described in U.S. Patent No. 4,746,180 issued to Wnuk e! October 9, 1984. This film is obtained from the Exxon Chemical Company of Lake Zurich, Illinois as the Exxon EXX-500 film (formerly EXX-7). Another preferred extensible backsheet 40 is an extensible adhesive film Formula # 198-388 manufactured by Findley Adhesives Company of Wauwatosa Wisconsin. Findley's adhesive film is a fluid-impermeable film capable of extending from 200 to 300%. Findley's adhesive film is preferred because it is also elastically extensible. At least one side of this film can be used with the adhesive (as it is in sanitary napkin 20). For example, this side of the film may be adhered to the garment-facing side 42B of the absorbent core 42. The other side of the adhesive film forming the garment-side 40B of the backsheet 40 may have its adhesive surface on the back. less partially covered (or "blocked", to eliminate its adhesive characteristics). The adhesive defining the side facing the body 40A of the backsheet can also be at least partially blocked. The exposed adhesive can be blocked in a number of suitable ways. These include, but are not limited to, attaching a layer of non-adhesive material to cover the exposed adhesive, covering with a brush or spreading a powder material such as talcum powder or corn starch on at least part of the exposed adhesive., and covering the exposed adhesive with a creped nonwoven material and / or nonwoven material that is oriented in a direction that allows the backsheet to extend (such as with most of its fibers running perpendicular to the desired direction of stretch) . The partial blocking of the exposed adhesive on the garment facing side 40B of the backsheet 40 can be used with the remainder of the exposed adhesive to create particular adhesive patterns for attaching the backsheet to the wearer's panties. In still other embodiments, the adhesive film can be created with one side having a tack adhesive and one side without a tack. A suitable adhesive film having these characteristics is a composite structure comprising a nonwoven elastomeric film, with a low modulus pressure sensitive adhesive such as the adhesive film Formula # 198-338 which is available with such a blocking film like Formula H2031 from Findley Adhesives Company. These materials are further described (and used for other purposes in U.S. Patent No. 5,032,120 issued to Freeland et al. On July 16, 1991; and in U.S. Patent No. 5,037,416 issued to Alien et al. on August 6, 1991. In still other embodiments, the backsheet 40 can be made extensible by performing a mechanical operation such as pleating, corrugation, rolling with ring, or SELF to the back sheet material. In the preferred embodiments in Figures 1 to 3, the backsheet 40 is formed by the treatment of film in structural elastic form (as described in U.S. Patent No. 5,518,801 issued to Chappell on May 21, 1996 ), one of the exemplary polymer films described above. This upper sheet material treated in the form of a film similar to the elastic structure is preferred over many of the elastomeric films described above because of its relatively low cost). The sanitary napkin 20 is also provided with one or more stiffening characteristics 44. The stiffening characteristics 44 may comprise any type of structure that provides greater initial stiffness to some or all of the sanitary napkin 20 parts. This higher initial stiffness is preferably present during the placement of the sanitary napkin 20 in an undergarment and as the undergarment is pulled toward the position. The increased initial stiffness does not continue for more than a brief period of time during the use of the sanitary napkin 20. The stiffening feature 44 may comprise a separate element of the sanitary napkin 20. In other embodiments, the upper sheet 38, the sheet back 40, or absorbent core 42 of sanitary napkin 20 may include stiffening feature 44. In a particularly preferred embodiment shown in Figures 1 through 3, stiffening characteristics 44 comprise a pair of brittle strip stiffening members 46. which act as leagues or struts. These brittle strips 46 provide the sanitary napkin 20 with increased initial stiffness until such time as the initial stiffness threshold during use has been exceeded. The forces of the sitting or walking user will cause the threshold of initial rigidity to have been exceeded and break the brittle strips 46. Preferably, the brittle strips 46 will break into small fragmented remnants which can be easily contained by the topsheet 38. , the backsheet 40 and the absorbent core 42, of the sanitary napkin 20 without significant interference with the absorbent function of the sanitary napkin 20. The breaking of the brittle straps 46 allows the sanitary napkin 20 to assume the generally flexible and preferably extensible condition. wanted. The brittle fiber stiffening members 46 preferably extend in the longitudinal direction in a continuous manner from the first end region 28, through the central region 32, and toward the second end region of the sanitary napkin 20. Preferably, the brittle strips 46 shown in Figures 1 and 2 are centered around the longitudinal centerline L of the sanitary napkin 20 and are disposed between the backsheet 40 and the absorbent core 42. The straps 46 may less preferably be disposed between the topsheet 38 and the absorbent core 42. In an even less preferred embodiment, the brittle strips 46 can be attached to the garment-facing side of the backsheet 40D. in this case, the top sheet 38, the back sheet 40 and the absorbent core 42, will not cooperate to contain the fragments of the strips 46 after they have broken the strips. The brittle strip stiffening members 46 may comprise any material having the desired characteristics. For example, brittle strip stiffening members 46 may comprise strips of woven or nonwoven material that have been made stiff and brittle through the application of sprayed starch. The gypsum band strips that have been allowed to dry have also been found to work well as the brittle strip stiffening members 46. Various variations are also possible on the brittle strip stiffening members 46. For example, the Figure 7 shows a sanitary towel in which the stiffening characteristics 44 comprise a pair of brittle strips 46, which are generally curved instead of straight. Preferably in this embodiment, the brittle strips 46 are oriented symmetrically about the longitudinal center line as shown in Figure 7, but this arrangement is not necessary. The brittle strip stiffening members 46 shown in Figure 7 may be constructed of strips of hardened starch material or strips of gypsum band which have been allowed to dry. Any other construction that creates a brittle beam or strut and will impart an initial stiffness to the sanitary napkin 20 until the initial stiffness threshold is exceeded can also be used.

Additional variations with the brittle strip stiffening members 46 include the absorbent articles with a simple brittle strip 46 as shown in Figure 8. In a less preferred embodiment, the brittle strips 46 may be oriented in the transverse direction as shown in Figure 12. A variety of variations are possible as any number of brittle strip stiffening members 46 can be used. In these or other embodiments, the brittle strips 46 can vary in length and be oriented in different directions. In a particularly preferred alternate embodiment shown in Figures 5 and 6, the stiffening feature 44 may comprise a separate tube fame element constructed from a tissue or a non-woven layer wrapped in a polypropylene layer or from a layer of polypropylene wrapped in a layer of tissue or non-woven material. The polypropylene layer is melted in the tissue, or the nonwoven layer thereby creating a relatively stiff tube structure 48. This relatively rigid tube structure 48 acts as the stiffening feature 44 in the preferred embodiment shown in FIGS. and 6. A polypropylene material that works well for this purpose is known as CELESTRA, which is available from Fiberweb, North America of Simpsonville, SC. A suitable non-woven layer is obtained as the DANWEB material # 1079-2338 and 2339 from Dan Web of Aarhus, Denmark. The stiffening members with tube structure 48 preferably extend along the longitudinal center line from the first end region 28, through the central region 32, and towards the second end region 30 of the sanitary napkin 20. Stiffening member 48 with tube structure can have any suitable cross section. Preferably, the tube structure 48 is disposed between the absorbent core 42 and the backsheet 40 of the sanitary napkin. When the initial stiffness threshold of the sanitary napkin 20 is exceeded (for example, as soon as the wearer sits down), the stiffening member 48 with the tube structure crushes and ceases to provide greater stiffness to the sanitary napkin 20. Once crushed, the tube-shaped stiffening member 48 preferably does not return to its tube shape and offers little resistance to bending, thus allowing the sanitary napkin 20 to exhibit its generally flexible and extensible characteristics. In a variant of this modality, the polypropylene layer is cast in a tissue layer, both of which are in the form of an inverted "V" as shown in Figure 6A. This creates an initially rigid inverted "V" 50 which functions as the stiffening feature 44 of the sanitary napkin 20 shown in Figure 6A. As with the tube-shaped stiffening member 48, the initially rigid inverted "V" 50 offers resistance to bending by virtue of its shape. The structure with the initially rigid inverted V 50 also crushes when the initial stiffness threshold of the sanitary napkin 20 is also exceeded. Subsequent to this crushing, the initially rigid V 50 offers little resistance to bending, thus allowing the sanitary napkin 20 to exhibit its generally flexible and extensible characteristics. Additional variations of this modality are also possible. The stiffening characteristic (s) 44 may comprise any structure that offers resistance to bending by virtue of its shape. The structure must be constructed in such a way that it will crush or otherwise deform when subjected to the forces of use, thus losing the shape provided by the resistance to bending described. During use, preferably, the structure should not continue to impart inflexibility or resistance to bending to the absorbent article described above. The sanitary napkin 20 may contain any number of tapering members 44 in the form of tube 48, inverted V-shaped 50, or other shape in a variety of lengths. These stiffening members 44 can be oriented in any direction. In a further series of the preferred embodiments shown in Figures 9 to 11, the stiffening characteristics 44 comprise stiffening zones 54 instead of beams or struts. The stiffening zones 54 may comprise an integral part of one of the elements of the absorbent article, preferably the absorbent core 42, or less preferably the topsheet 38 or the backsheet 40. Alternatively, the zones of stiffness 54 may comprise a separate element preferably positioned above the absorbent core 42, below the absorbent core 42, or within the absorbent core 42. { for example, such as between the layers of a laminated absorbent core). In a preferred embodiment, the sanitary napkin 20 shown in Figure 9 has three stiffening zones 54. Two of the stiffening zones 54 are generally located in the second end region 30 while the third is generally located in the first end region 28. and may extend towards the central region 32. Preferably, the stiffening zones are located asymmetrically about the longitudinal center line L. In another preferred embodiment shown in Figure 10, the sanitary napkin 20 is provided with two stiffening zones 54. Figure 11 shows a sanitary towel 20 provided with a stiffening zone 54 around the perimeter of the sanitary napkin 20 inwardly of the seam 90. These examples are representative and the precise arrangement of the stiffening zones 54 may differ. Any number of zones 54 can be used and the size, shape and orientation of each can be varied to provide the absorbent article with an initial stiffness threshold that meets the objects of the invention described above. The stiffening zones 54 may comprise a non-woven polypropylene material such as the melted CELESTRA non-woven material in a tissue layer such as the DANWEB tissue layer. The resulting composite material serves as the stiffening feature 44 and is attached to the top and bottom of the absorbent core 42, in a suitable manner known in the art. In the variations of this embodiment, any material from which a brittle film can be formed can be used for the areas of stiffness 54. For example, a thin film of sodium silicate, known as level glass, can serve as a suitable material from which stiffening zones 54 are constructed. Pieces of nonwoven tissue material hardened with gypsum, corn starch or other material that results in a brittle film, can also be used to construct the stiffening zones 54. The resulting hardened tissue or nonwoven material is attached to the top or bottom of the absorbent core as described above in a manner known in the art. technique. The stiffening zone 54 can also be created as an integral part of the absorbent core 42, less preferably the backsheet 40, still less preferably the topsheet 38. These integral stiffness zones 54 in a preferred embodiment can be created by stiffening the garment-facing side of the absorbent core 42B with a thin layer of sodium silicate (level glass), of Alternately, a thin layer of plaster or other suitable material may be used for this purpose. In a less preferred embodiment, the side facing the body of the absorbent core 42 may be hardened in any manner described above. Similarly, in still less preferred embodiments, the backsheet 40 or the topsheet 38 can be provided with an integral stiffening zone 54 using any of the previously described materials or other suitable materials. The components of the main body portion described above (the topsheet 38), the backsheet 40 the absorbent core 42 and the stiffening member 44) can be assembled in any suitable manner. in the preferred embodiment shown in Figures 1 to 3, the components of the main body portion are assembled in a "sandwich" configuration, with the components dimensioned such that the edges of the upper sheet 38 and the back sheet 40 extend outward, beyond the edges of the absorbent core 42. The topsheet 38 and backsheet 40 are preferably at least partially peripherally joined using known techniques. As shown in Figure 1, the topsheet 38 is preferably secured to the backsheet 40 along a seam, such as the seam 90. The seam 90 is preferably impervious to liquid. The seam 90 can be formed by any means commonly used in the art for this purpose such as by gluing, pleating or heat sealing. The term "joined", as used herein encompasses configurations in which one element is directly secured to the other element by fixing e! element directly to the other element, configurations in which the element is indirectly secured to the other element by fixing the element to a member or intermediate members which in turn are fixed to the other element and configurations in which one element is integral with the other element, that is, one element is essentially part of the other element. The components of the sanitary napkin 20 can be joined together by adhesives, stitches, joints with heat and / or pressure dynamic mechanical joints, ultrasonic bonds, intermeshing or entanglement of the fibers or other hydraulics comprising the components of the sanitary napkin, such as by blowing molten state fibers comprising one of the components on other components, extruding one of the components on the others, or by any other means known in the art. Suitable means for joining the components of the sanitary napkin are described in U.S. Patent Application No. 07 / 810,774 filed in the name of Cree et al., December 17, 1991 (PCT Patent Publication No. WO 93). / 11725 published on July 24, 1993). When the main body portion is composed of extensible components, the components can be joined together in any suitable manner that allows the main body portion to extend. The combination of the top sheet and the back sheet 40 in an extensible product can not always be achieved by traditional sealing methods or materials used for non-stretch products. The joints formed by traditional methods of heat and pressure often do not stretch or are brittle in such a way that they can easily break or tear when the product is stretched. This is particularly a problem when the upper sheet 38 and the back sheet 40 have different elastic properties or melting points, or are of sufficiently different composition that sealing is difficult even when these components do not stretch. In a particularly preferred embodiment of the sanitary towel 20 shown in Figures 1 to 3, the parts of the upper sheet 38 and of the upper sheet 40 on the edges of the upper sheet 38 and of the rear sheet 40 are secured together using an expandable adhesive 92 around the perimeter 26 of the sanitary napkin and in addition, a distribution of preferred mechanical junctions 94 in the perimeter area 26. The extendable adhesive 92 provides an extensible impermeable seal around the perimeter 26 of the sanitary napkin 20. The mechanical seams 94 (are a part of which are shown in FIG.

A Figure provide additional resistance. The mechanical joints 94 are arranged in intermittent zones (or regions of the joined and unattached areas). The sanitary napkin 20 also preferably comprises side wrapping elements 52 located along each longitudinal edge 22 of the main body portion 21. These side wrapping elements are described in United States Patent Application Serial No. 08 / 192,240 filed in the name of Osborn III and others on February 4, 1994 (PCT Application Publication No. WO 95/20931 published August 10, 1995). The garment surface 20B of the sanitary napkin 20 and the garment surface of the side wrapping elements 52 may include fasteners for securing the sanitary napkin 20 to the wearer's undergarment. Figure 3 shows that in the particularly preferred embodiment shown in the drawings, the sanitary napkin is provided with two end fasteners 84 and the perimeter fastener 86, a fastener that is arranged around the perimeter of the main body portion 21 which is adapted to secure the potion of the sanitary towel 20 that covers the main body portion 21 to the crotch region of an undergarment. The end fasteners 84 are preferably non-extensible fasteners, such as non-extensible adhesive patches. The end fasteners 84 serve to firmly anchor the ends of the pppcipa body portion! 21 in the wearer's panties. The perimeter fastener 86 is preferably an extensible fastener, such as an extensible adhesive. The extension capacity of the perimeter fastener 86 assists the parts of the sanitary napkin between the ends of the main body portion 21 in extension during use. The non-extensible end fasteners 84 may comprise any adhesive or glue used in the art for this purpose with pressure sensitive adhesives being preferable. Suitable adhesives are Century A-305-2823 manufactured by National Starch Company, 3 Sigma 3153 manufactured by 3 Sigma and Fuller H-22238ZP manufactured by HB Fuller Co., Suitable adhesive fasteners are also disclosed in US Pat. 4,917,697. The extensible adhesives suitable for using the perimeter fastener 86 include extendable adhesives, per se, and extensible adhesive / backsheet combinations. Any of the adhesives known in the art can be used. Suitable combinations of extensible adhesive / backsheet include, but are not limited to, the non-extensible adhesive used on a backsheet extensible material such as 3 Sigma 2474 available from Anchor Continental, 3 Sigma Division of Covington, Ohio; elastically stretchable adhesive films such as adhesive 198-338, or an elastically stretchable adhesive film known as 3M XPO-0-014 available from the Minnesota Mining and Manufacturing Company of St. Paul, Minnesota, or spray adhesives such as 3M adhesive 1442 on a low modulus elastic film. The end fasteners 84 and the perimeter fasteners 86 are preferably removably covered before use, the sanitary napkin 20 by the release paper 88 shown in Figure 1. When the sanitary napkin of the present invention is removed from its package , the stiffening characteristic keeps the sanitary napkin in an initially rigid condition. The center of the main body portion is placed in the crotch portion of the wearer's panties with the back sheet in contact with the inner surface of the panty portion and one end of the main body portion extending toward the section front of the panty and the other end towards the posterior region. The end fasteners and the perimeter adhesive combine to hold the main body portion in position. The distal portions of the side wrapping elements are folded around the elasticized edges of the screen. The side wrapping elements can be secured to the underside of the panty with the fin adhesive, but this fin adhesive is not necessary. Once the sanitary napkin is secured to the pantyhose in the position as described, the wearer pulls on the panties achieving body contact with the sanitary napkin. The forces exerted on the sanitary napkin by the wearer's body will cause the stiffening feature to cease to provide increased initial stiffness allowing the sanitary napkin to add a more flexible condition. The terms "panty liners"; and "pantiprotector" refers to absorbent articles that are less bulky than sanitary napkins, which are generally worn by women between their menstrual periods. Suitable absorbent articles in the form of pantiliners which can be provided with the stiffening characteristic described herein, is disclosed in U.S. Patent No. 4,738,676 entitled "Pantiprotector" issued to Osborn on April 19, 1988. The term " incontinence article, "refers to pads, undergarments (pads held in place by a suspension system, of some type, such as a belt, or the like), inserts for absorbent articles, capacity enhancers for absorbent articles , trusses, bed pads and the like, regardless of whether they are used by adults or other incontinent persons. Suitable incontinence articles that can be provided with the stiffening feature described herein are disclosed in U.S. Patent No. 5,304,161 issued to Noel et al. On April 19, 1994; and in U.S. Patent No. 5,300,054 issued to Fesit et al. on April 5, 1994. The disclosures of all patents, patent applications, and any of the patents issued thereon, as well as any of the corresponding published foreign patent publications), and publications mentioned throughout this patent application are hereby incorporated by reference herein. However, it is not expressly admitted that any of the documents incorporated by reference herein, teach or disclose the present invention. It is also not expressly admitted that any of the commercially available materials or the products described herein teach or disclose the present invention. Although particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications may be made without departing from the spirit and scope of the invention.

Claims (10)

1. An absorbent article for use in an undergarment, the absorbent article comprising a liquid pervious topsheet, a liquid impermeable backsheet attached to the topsheet, and an absorbent core positioned between the topsheet and the backsheet; said absorbent article characterized in that the absorbent article has an initially hardened condition and a later more flexible condition, said absorbent article further comprising stiffening means for maintaining at least part of the absorbent article in said initially rigid condition when the absorbent article is handled before use and to allow the absorbent article to assume said more flexible condition when the absorbent article is used. The absorbent article according to claim 1, wherein the stiffening means comprises an integral stiffening feature provided at least one of the topsheet, the backsheet and the absorbent core. 3. An absorbent article according to claims 1 and 2, wherein the stiffening means comprises one or more stiffening zones. An absorbent article according to any of the preceding claims, wherein the topsheet and the backsheet are attached to the perimeter of the absorbent article to form a perimeter seam and said stiffening means are to an area of perimeter stiffness located inside the perimeter seam. An absorbent article according to any of claims 2 to 4, wherein the stiffening means is formed by stiffening at least one of the topsheet, the backsheet, or the absorbent core with corn starch. 6. An absorbent article according to any of claims 2 to 4, wherein the stiffening means is integral with the absorbent core and is formed by applying a thin rigid film to at least one side of the absorbent core. An absorbent article according to any of claims 1, 3 and 4, wherein the stiffening means comprises at least one stiffening member juxtaposed at least one of the upper sheet, the back sheet and the absorbent core. 8. The absorbent article according to claim 7, wherein the stiffening member comprises at least one broken strip or > , preferably disposed between the upper sheet and the back sheet, more preferably disposed between the back sheet and the absorbent core, which breaks into a plurality of pieces when the absorbent article is used due to the forces exerted or the absorbent article by the body of the absorbent article. the user. 9. The absorbent article according to claim 8, wherein the brittle strip comprises a strip of material that has been hardened with a material selected from the group consisting of gypsum and maize ain. The absorbent article according to claim 7, wherein the stiffening member comprises a structure selected from the group consisting of a tube-like structure and an inverted "V" shaped structure, said preferably formed structure being constructed melting a polypropylene material on a tissue layer.