MXPA00004725A - Absorbent articles with means for achieving or maintaining convexo-concave bunching - Google Patents

Abstract

The present invention relates to absorbent articles comprising a means to achieve or maintain a convexo-concave shape with an upwardly bulged (i.e. towards the wearer during use) center crotch part, and outwardly bulged parts at the longitudinal ends of the article following the body curvature to surround the waist.

Description

ABSORBENT ARTICLES WITH MEANS FOR OBTAINING OR MAINTAINING THE CONVEX-CONCAVO GROUPING GENERAL FIELD OF THE INVENTION The present invention relates to hygienic absorbent articles, in particular absorbent articles designed to receive large quantities of body fluids such as urine and / or faecal material, such as adult incontinence articles or baby diapers.

BACKGROUND / PREVIOUS TECHNIQUE Absorbent articles for use in hygienic applications are well known in the art. Also, the formation of these absorbent products has been discussed in depth, both with respect to the outline of the article (in contrast to eg rectangular), but also with respect to the three-dimensional shape. The pads for feminine hygiene in particular have been disclosed having improved body contact to receive exudates from the body by adapting the article three-dimensionally. U.S. Patent No. 5,300,055 (Buell) discloses an absorbent article having a surface that gives the body which has an upwardly convex surface, such that the total article either takes the form of a "U" (ie, the opening of the U giving away from the user) or of a "W". In the international publication WO 95/31165 (Olsen) a similar article is described, leading to a configuration in the form of "W" by means of a resilient component as an integral part of the article. *% _f In the international publication WO 95/17148 sanitary napkins are disclosed, which achieve improved contact between the wearer's lips and the article for improved fluid handling capacity (ie, menstruation). Also in the international publication WO 88/04547 (Thoren) describes a sanitary towel that deals with the improved contact between the article and the user by fixing elastic members both in the machine direction and in the transverse direction of the machine on that side of the machine. upper sheet that is oriented away from the user. Also European patent EP-A-0302 523 (Lassen) describes an anatomically shaped female pad. made by forming, molding or other forming techniques. In United States Patent No. 5,098,4233 (Pieniak) the adjustment aspects of absorbent articles such as baby diapers are discussed. The primary approach is proposed against the narrow widths of the crotch, such as by folding the diaper in the crotch region 2x, 4x, 6x or 8x. This folding can be achieved by the so-called folding in W, by which the absorbent article takes the form of a "W". There is no disclosure about the formation or bending of the core in relation to the elements of the chassis. However, the prior art has not sufficiently considered that there are specific training requirements and benefits within the context of adult incontinence articles or baby diapers with relatively high amounts of fluid discharges. Also, prior art has failed to achieve additional benefits of specific adaptation for articles intended to receive fecal material. Therefore, there is still a need to improve both the comfort aspects of these items and the management of body exudates at the same time.

OBJECTS OF THE INVENTION Accordingly, it is an object of the present invention to provide absorbent articles particularly designed to receive relatively large amounts of exudates from the body such as urine, whereby the articles do not unduly raise discomfort for the user, without impacting in a detrimental manner. the operation of the article. It is a further aspect of the present invention to provide these articles that have improved handling capacity in an additional manner with respect to fecal eses. It is a further object of the present invention to provide designs that at the same time satisfy these requirements and allow easy application to the user, either by herself, or by another person such as a relative or a caregiver.

BRIEF DESCRIPTION OF THE INVENTION The present invention relates to absorbent articles that comprise a means for obtaining or maintaining a convex-concave shape with the central part of the crotch warped upward (i.e., toward the wearer during use), and warped outward portions in the longitudinal ends of the article following the curvature of the body to surround the waist.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 shows an absorbent pad as an example of an absorbent element; Figure 2a shows the cross-sectional view of a thin slice of the urinary loading area of an article grouped in the O-shape according to the present invention. Figure 2b shows the cross-sectional view of a thin slice of the urine loading area of a comparative prior art article in the form bent in W.

DETAILED DESCRIPTION An absorbent article generally comprises: an absorbent member (often referred to as the core or core structure, which may consist of sub-structures); "chassis elements", such as a fluid-impermeable backsheet; additional optional features such as closure elements; or elastification Within the context of the present disclosure, an absorbent article can be "unitary", ie, all elements are joined together such that the article is, when used, essentially one piece or the absorbent article may consist of of separate elements such as having an absorbent element and an external fastening element, for example, a reusable fastening stretch garment such as is often practiced for adult incontinence articles in the form of an elasticated panty combination with a Disposable absorbent pad. In any case, the article or its elements may be disposable or capable of being reused, whereby the term "disposable" is used herein to describe articles or absorbent elements that are not intended to be washed or restored or returned to. otherwise used as an article or absorbent element (i.e., they are intended to be disposed of after a single use and, preferably, to be recycled, composted or otherwise disposed of in an environmentally compatible manner). The absorbent article has a lateral direction (direction x or width) defined as the direction parallel to the lateral center line and which is aligned with a direction from left to right of the user when it is used; the longitudinal direction (direction and or length) being defined as the direction parallel to the longitudinal center line and aligned with the elevation direction of a user in a standing position during use; and the axial direction (direction of thickness) being defined as the direction extending through the thickness of the diaper 20. The term "concave" means, in the context of the present invention, a curvature that is "warped outwardly", such as when the general curvature of the waist of a human user is followed, that is, a belt worn around the waist would exhibit a generally concave curvature. The term "convex" is related to the opposite curvature. Of course, these terms are related, and also linked to the terms "up" and "down", which follow the general understanding of gravity. In the following, a letter "U" would have a "convex down" shape, or a concavity. The Greek capital letter O (Omega) has a curvature "convex upwards" in the central part. If the terms "concave" and "convex" are used without an "up" or "down" direction, the meaning is "up". If these terms are used when referring to a user's position, it is assumed, unless otherwise distinguished, that the user is in a standing position.

In Figure 1a, b and c the present invention is exemplified by describing the absorbent member of an absorbent article, which may be a baby diaper or an adult incontinence pad. The pad comprises an absorbent core 10, designed to absorb and contain fluids, in many examples based primarily on water. The absorbent core 10 can be any absorbent medium that is generally compressible, capable of forming, and capable of absorbing and retaining primarily aqueous liquids. Examples of suitable absorbent materials include ground wood pulp, creped cellulose wadding; blown polymers in the molten state; chemically hardened, modified or cross-linked cellulosic fibers; tissue including tissue wraps and tissue laminates; absorbent foams; absorbent sponges; superabsorbent polymers; gelling absorbent materials; or any equivalent material or combinations of materials. The configuration and construction of the absorbent pad can also be varied, (e.g., the absorbent pad may have varying gauge zones, a hydrophilic gradient, a superabsorbent gradient, or acquisition zones with lower average density and lower average basis weight; understand one or more layers or substructures). Preferably, the absorbent pad has an essentially planar configuration to avoid complications that may arise from having a three-dimensionally tightly adapted shape. Exemplary absorbent structures for use in the absorbent pad as used in the disposable industry are described in U.S. Patent No. 4,610,678 entitled "High Density Absorbing Structures" issued to Weisman et al. On September 9, 1986; U.S. Patent No. 4,673,402 entitled "Absorbent articles with cores in double layers" issued to Weisman et al. on June 16, 1987; U.S. Patent No. 4,888,231 entitled "Absorbent Core Having A Dust Cap" issued to Angstadt on December 19, 1989; and in U.S. Patent No. 4,834,735, entitled "High density absorbent members having acquisition zones with lower density and lower basis weight" issued to Alemany et al. on May 30, 1989. Other pad designs are described. absorbent in European patent applications Nos. 93305150.0 and 93309614.1. U.S. Patent No. 4,411,660 discloses an absorbent product of two layers of absorbent material of different types, such that the upper layer forms gel slower than the first layer. The description of the European patent EP-B-0 401 189 discloses that the favorable properties of the absorbent products can be obtained by using two different types of gelling absorbent material in separate layers, instead of a mixture of the two gelling absorbent materials. in an individual layer. The hydrogel-forming absorbent polymers using the present invention include a variety of polymers capable of absorbing large quantities of liquids, substantially insoluble in water, but capable of swelling with water. These polymeric materials are also commonly referred to as "hydrocolloids", or "superabsorbent" materials. These hydrogel-forming absorbent polymers preferably have a plurality of functional groups, anionic, such as sulfonic acid, and more typically carboxy groups. Examples of polymers suitable for use herein include those which are prepared from acid-containing, unsaturated, polymerizable monomers. Thus, these monomers include the olefinically unsaturated acids and the anhydrides containing at least one olefinic carbon-to-carbon double bond. More specifically, these monomers may be selected from the olefinically unsaturated carboxylic acids and acid anhydrides, olefinically unsaturated sulfonic acids, mixtures thereof.

As described above, the hydrogel-forming absorbent polymers are preferably slightly network crosslinked. Cross-linking in the network serves to make the polymer substantially insoluble in water and, in part, determines the absorption capacity and the characteristics of the content of the extractable polymer of the precursor particles and the resulting macrostructures. The processes for network crosslinking typical polymers and crosslinking agents in the network are described in greater detail in the aforementioned US Pat. No. 4,076,663, and in German Patent DE-A-40207890 (Dahmen). . In order to be able to compare absorbent articles for varying end-use conditions, or differently sized items it has been found that "design capability" is an appropriate measure. For example, babies are representing a typical group of use, but even within this group the amount of urine load, the frequency of loading, the composition of the urine will vary widely from the smallest babies (newborn babies) to babies that crawl on one side, but also for example among several babies that crawl particular. Another group of users may be larger babies, still suffering from a certain form of incontinence. Also, incontinent adults can use these items, again with a wide range of load conditions, usually referred to as light incontinence that varies up to severe incontinence. Thereafter, absorbent articles that are able to cope with these requirements should have the ability to capture these amounts of urine, which has been referred to for further discussion as "design capability" which is described in more detail below .

These quantities of fluid have to be absorbed by the materials that can finally store the bodily fluids, or at least the aqueous parts thereof, so that, if there is, only little fluid is left on the surface of the article towards the user's skin. . The term "final" refers in one respect to the situation as in the absorbent article in intervals of prolonged uses, and in another respect to the absorbent materials that reach their "final" capacity when they reach equilibrium with their environment. This may be in such an article under the actual conditions of use after prolonged use intervals, or this may also be in a test procedure for pure materials or composite materials. Since many of the processes under consideration have an asymptotic kinetic behavior, one skilled in the art will readily consider the "final" capacities that are reached when the actual capacity has reached a value sufficiently close to the asymptotic endpoint, for example, relative to the accuracy of equipment measurement. Since an absorbent article may comprise materials that are primarily designed to ultimately store the fluids, and other materials that are primarily designed to satisfy other functions such as the acquisition and / or distribution of the fluid, but may still have some final storage capacity , materials suitable for the core according to the present invention are described without attempting to artificially separate these functions. However, the final storage capacity for the total absorbent core can be determined, for the regions thereof, for the absorbent structures, or even for the substructures, but also for the materials as used in any of the above. As discussed in the above to vary the dimensions of the article, one skilled in the art will be able to easily adopt the appropriate design capabilities for other groups of intended users. For example, for incontinence articles of adults intended for use with severely incontinent people may contain 9 grams, of superabsorbent material having an absorbent capacity of approximately 31 ml / g when subjected to the well known centrifugal capacity test of the Tea bag, and contains 97 gr. of conventional cellulosic oil felt having a capacity of approximately 4 ml / g, resulting in a total final storage capacity of approximately 667 ml. Other examples relate to articles for people with light continence. For example the ATTEND MINI has a final storage capacity of approximately 70 ml, ATTENDS MINI PLUS of 90 ml., Or ATTENDS NORMAL of approximately 167 ml., With all of these products sold by Procter &; Gamble in several countries in Europe. Referring again to Figure 1, said absorbent core has waist regions 14, 15, contiguous with the longitudinal edges 12, 13, and a crotch region 11 connecting these regions 14, 15, which has a minimum width OA As exemplified in Figure 1a, the width in the waist region 14, 15 is approximately twice the width of the crotch region 11. The absorbent core 10 is connected to a back sheet 16 impervious to the fluid. backsheet 16 may comprise a woven or non-woven material, polymeric films such as polyethylene or polypropylene thermoplastic films, or composite materials such as a film-coated nonwoven material.Often, the backsheet is a thermoplastic film having a thickness from about 0.012 mm to about 0.051 mm, such as blown or emptied polyethylene film as available under the designation RR8220 (blow film) ada) and RR5475 (film cast) as manufactured by Tredegar Industries, Inc. of Terre Haute, IN. This backsheet 16 is preferably embossed and / or dull finished to provide a more fabric-like appearance.

In addition, and often preferably, backsheet 16 can allow vapors to pass therethrough while still preventing exudates from penetrating through backsheet 16. Backsheet 16 can have both length and width dimensions exceeding the dimensions of the absorbent core 10, thereby forming the peripheral edges. The region of the backsheet 16 extending outwardly from the core in the longitudinal direction is referred to as the end flaps. The relatively wide lateral edges 17, 18 of the backsheet 16 are bent inward to at least partially cover the absorbent core 10. The free longitudinal edges 19, 20 comprise an elasticizing feature 21, 22, such as a band or elastic strip . When the absorbent article is stretched to leave it flat as indicated in Figure 1, these characteristics are stretched to allow contraction for the best compliance to the body during use. The lateral edges 17, 18 are now in a tubular arrangement 23, 24 with the parts unfolded, whereby the stretched elastic bands which are connected at their ends to the edges 25, 26 respectively 27, 28 of the lateral edges 17, 18 folded inwards. A top sheet 29 is placed on the absorbent core 10 facing the user during use. The upper sheet 29 is docile, of soft feel. In addition, the topsheet 29 is permeable to liquid allowing liquids such as urine liquids to easily penetrate through its thickness. A suitable top sheet can be manufactured from a wide range of materials, such as porous foams; cross-linked foams; plastic films with openings; or woven or nonwoven webs of natural fibers (e.g., wood or cotton fibers), synthetic fibers (e.g., polyester or polypropylene fibers), or a combination of natural and synthetic fibers. There are a number of manufacturing techniques which can be used to manufacture the sheet 29. For example, the top sheet 29 can be a web of spunbonded non-woven fibers, carded, wet-laid, meltblown, hydroentangled, combinations of the above, or similar. A top sheet frequently used is carded and thermally bonded by means well known to those skilled in the art of the fabrics, for example, made of cut length polypropylene fibers as manufactured by Veratec, Inc., a division of International Paper Company, of Walpole, Massachusetts under the designation P-8. The topsheet can be essentially bonded through most or all of the surface of the absorbent core, or it can only be partially joined thereto. The top sheet may comprise openings to facilitate the penetration of the exudates therethrough, such as urine and faeces. The top sheet may also be fully or partially elasticized. In order to maintain the absorbent member as described above on the wearer's body and the register with body openings that release fluid from the body, the absorbent article must have one or more attachment means. Said fixing means can be of the mechanical type, that is to say, essentially aimed at overcoming the forces of gravity or frictional forces between the article and the external elements, such as the external pads of the user and / or the bed elements exploiting the frictional forces between the article and the wearer's skin, or structural support forces such the registration with the contour of the body such as the bones of the user's hip. The absorbent element can be retained in place alternately by conventional closure systems for securing the article or absorbent element around the user's waist, such as by integral tape systems, which can comprise tapes coated with adhesive or elements mechanically coupling.

In this manner, the absorbent article or the absorbent element is provided with a closure system comprising a tape tab fastening device and a tie-down member. The tape tab fastening device comprises a joining area and a functional area, and the clamping member is preferably a reinforcing strip or the alternative a portion of the back sheet. The functional elements may adopt a number of configurations such as adhesive fasteners, mechanical fasteners, a combination of adhesive fasteners and mechanical fasteners, or any other means as is known to those skilled in the art. For these closure systems surrounding the user's waist, the article is preferably also comprising elasticizing characteristics operably connected with these closure features, to increase and sustain the fit of the article during use. Absorbent articles, which are sometimes referred to as "calf-style diapers" are unitary items with a calf-style design, ie, with the side seams closed to form a completely closed structure in the crotch region, together with the features of elasticizing to allow fixation as the said elastic underpants, and also an absorbent core such as a pantyhose comprising the elasticized region and which is further described in European Patent Application No. 96112413.8, filed on the 1st. August 1996. Alternatively, an absorbent element as described above, may simply have a means to secure it to the user's normal undergarment, as is often applied for items of light female hygiene such as as the so-called pantiprotector, and indicated in Figure 1c, by the fixing means 30.

An additional induso alternative has a topical adhesive fixation type fastening means. Such means of "body adhesive" aims at fixing the article directly to the user's skin, and are described as in the European patent application 9710666.91. A further embodiment of the present invention relates to non-unit articles, which comprise an absorbent element and separate fastening means or separate fastening garment such as a mesh or stretch pant, which can be used either as a replacement or in addition to the user's regular undergarment. A similar approach to these non-unitary elements may be a fixable belt as described in European Patent EP-A-0,409,307 (Gipson et al.). In addition, the absorbent articles according to the present invention can have several of the aforementioned fixing means, such as having both a body adhesive applied to the absorbent element, and a further garment or stretch in a double fixation means arrangement. In the case of a non-unitary arrangement, both the absorbent element and the fastening element may be disposable, or one or both of these may be capable of being reused, such as after washing.

Absorbent articles in the form of O (Omega) In addition to the features as described above, the following embodiments make the present invention particularly suitable for being used to receive exudates of urine and / or faeces. The first and essential element is a feature for providing a convex warp at least in the crotch region, and in particular at least in the region or area of urine load, during application of the article to the user and / or during use. The urine loading area is generally located a little, i.e., often at about 5 cm, forward of the crotch point of the article, which corresponds to the narrowest width dimension of the stiffer part of the article. This convex warpage can be obtained by means arranged in the crotch region of the article and in particular in the urine loading area of the article, with placing the center line of the article during use in closer proximity to the user's body than the lateral side edges of the absorbent member tighter together than in the flat form and in this way having its central line more placed closer towards the body of the user than the side edges, such that the absorbent member is in effect warping up towards the user. In Figure 2a, the absorbent core 228 is forming the convex upward shape (ie, the central part of an O (Omega) .The lower parts of the O (Omega) are formed by the elements of the chassis, i.e. mainly the backsheet materials such as films and / or nonwoven materials This configuration is referred to as "warped-O." This convex O shape of the absorbent core must be at least about the urine loading point, preferably extending at least about +/- 2.5 cm towards the front and towards the back of the article, in order to allow comfortable use, this convex configuration of the core of the crotch region will change towards the concavely formed curvature of the parts of the crotch region. the front and back waist of the article to fit well around the user's waist, the elastic elements to maintain the lateral margins of the article in contact with the legs of the user are also placed with the zones of the bottom of the O.

This provides particular benefits against articles of the prior art which adopt the "U" shape, or the shape of a W as illustrated in Figure 2b, which schematically shows a cross section through a thin slice of an article of the prior art 320, with the total absorbent element formed or bent in this W shape. The O (Omega) grouping of the present invention allows cavities to form longitudinally away from the absorbent member, which may provide certain benefits during use . Since the absorbent member will be loaded on its upper "shoulder" (230), it will capture on one side the exudates of the body effectively, since there is only little space for the fluids to go elsewhere. Second, gravity helps, even when using highly functioning materials and structures, the penetration of the fluid into the receiving material, thus minimizing the residence time of the liquid on the surface, and thus the potential of the fluid. Rewetted from the user's skin or leakage to the outside. This advantage becomes even more pronounced, when combined with core structures that have less than optimal liquid handling performance. Even if the urine did not penetrate into the article immediately upon contact with the article, it would "deviate" along the slopes of the convex bump facing upward (ie, the slopes of the O [Omega]) . If, as could happen with the performance cores or smaller capacity, the core is (permanently or momentarily) saturated in this wet region, the fluid that would not penetrate the core, will be trapped by the waterproof sides of the O (Omega), which provides good sealing against the external garment of the wearer by the liquid impervious backsheet (216).

A further advantage becomes apparent in Figures 2a and 2b, where the absorbent core is illustrated after it has absorbed significant amounts of urine. This leads to the impending swelling of the core as indicated by the boundaries or flanges after inflating 240 and 242, which, in the case of a conventional W-folded core, will fill the deepest parts of the W, almost creating a full crown full, in particular under the impact of the user's movement. In particular for the cores comprising absorbent materials, which tend to reduce the liquid permeability of the matrices they comprise, this can lead to the situation where the lower parts of the W (oriented away from the user), are hidden in their swelling, this being due to repression of the geometric expansion or lack of fluid transport to these parts. However, in the case of the present invention the core will swell only the convex warpage of the "O", without the substantial impediment of fluid transport in a negative manner. If in combination with a high-performance core, the functionality of the grouping in O with respect to fluid handling changes, now the requirement for lateral sealing becomes less important, but the "O" (230) shoulder provides the directional flow in the transverse direction, which however, will increase the rate of liquid acquisition by increasing the load area in the transverse direction, thus also allowing significantly improved longitudinal fluid distributions. In addition, when the article is loaded with fecal eses, these can be deposited within these longitudinally oriented cavities positioned laterally outwardly of the absorbent core, thus leaving the absorbent member surface free to receive additional urine loads. In particular with relatively thin faecal esters (or watery, or of lower viscosity), they can for example when the user is in a standing position due to gravity flowing down towards the crotch region. Neverthelesshaving a bump up there, and sealing the non-absorbent side, the fecal eses will not cover the absorbent core and do not impair its functionality to receive the urine. In both examples, the backsheet (216) has to resist this load, and should not, even when designed to allow the vapors to penetrate through it, allow permeation under normal conditions of use. As will also be readily appreciated, these longitudinal side cavities need to be sealed against the wearer's skin, such as by resilient means (234), placed between the backsheet (216) and the top sheet (236). For the scope of the present invention, these cavities can also be formed by so-called "leg bends" as is well known in the art such as for baby diapers, for example in European Patent EP-A-0,263,720 . In a preferred embodiment of these "leg bends", the upright part of the secondary fold is positioned laterally outward from the fixed base part of the same fold, such that these folds are prevented from aligning on the surface of the absorbent core, and reduce in this way the ability to quickly receive even repeated discharges as well. A particularly preferred embodiment for the present invention comprises a chassis by which these cavities are made by bending inwardly and joining the material of the backsheet and the topsheet having elastic threads on their edges longitudinally of course, as described in FIG. European Patent EP-A-0.098.512 (Beckestram).

A further element of the present invention results from the transition from the convex warp in the crotch area to a concave warp in the waist area when worn. As is well known from fixed considerations, arc-type structures have a certain structural strength. This structural strength is an essential element of the present invention in the crotch region, whereby the upward bending creates such an arc-like structure. As indicated in the above, this convex warp has to be transformed into a concave structure in the waist region of the article. As it can be easily visualized with the piece of paper which is bent in a direction in the middle part and in the opposite direction at either end, this transition zone has a significant resistance and resistance to deformation. Within the current context, this results in "cavities" being formed, or hollow spaces between the article and the user's body, during use. These cavities can have a desired effect, since the fecal eses can be trapped in the hollow space formed by the grouping in O on the user, mainly where the convex shape in the crotch region transforms into the concave shape in the part of the upper back waist of the article, creating a "cavity of rear fecal eses". This cavity may have an adequate volume to receive fecal discharges, and comprises from about 10 cm3 to about 500 cm3 or more. These cavities can also have a benefit in a specific gender article design, especially when a cavity is formed by the frontal transition zone, thus forming a space for the male genital organs. These cavities may also be undesirable, for example in articles intended for the use of light incontinence without the intention of being loaded with fecal eses, or in the front area of a used female product, especially with absorbent cores that are relatively rigid by themselves (such as through highly densified cellulose structures). In all cases, it will be desirable to have the transition not in an arbitrary position, but instead in the desired location. Accordingly, a preferred embodiment of the present invention includes "joints" for the transition defined from the convex shape to the concave shape. The relative dimensions of the convex, concave and transition regions depend, of course, on the intended use and the user. However, generally the configurations of the human body are such that the lateral extent of the article during use should be small, preferably less than 7 cm, more preferably less than 5 cm, and most preferably even less than about 4 cm. In the case of a bent core, this dimension is related four times with the thickness of the core, in the case of the nucleus grouped in O, this is related to only twice the thickness of the core (when neglecting the thickness of the related materials without core). The length of the convexly grouped region should be at least about 5 cm, to allow adequate contact in the discharge region. The upper limit for this region depends on the intended use, and varies from a little more than the minimum of 5 cm as described (for example, for urine, female incontinence products) to approximately 20 cm for items intended to also receive eses fecal and requiring a "cavity of fecal escales back." After having described how the various elements of the present invention interact with each other, a more detailed description of the individual features will follow.

Means to sustain the O-shape (Omega) At present, many absorbent articles are produced flat, ie having no specific three-dimensional shape. The person who applies the item (ie, the user himself, or a person who helps such as a carer, family or similar) can apply the article in several ways, and through several application steps. Even if the absorbent articles are applied to the user such that they form the preferred O-shape at least in the crotch zone, normal movements in use or the load itself may result in the O shape not being maintained sufficiently sharply. and / or for a sufficiently long period. In this way, in order to maintain the form of O, the article is provided as a means to improve the maintenance of the form of O during the application of the article to the user, and also during the period of use. Said means for providing the grouping in O may be any means, which is capable of deforming or maintaining the deformation of the absorbent member in the crotch region such that the above described figure is formed during application and during use. The simplest way to achieve the form of O during the application of the article to the user is to fold the article in the appropriate form by the manufacturer. Therefore, the article needs to be folded along the longitudinally extending center line such as the top sheet. Which is intended to be user-oriented during use, located outwardly and the backsheet, which is intended to be placed outwardly or towards the user's garment into this folded portion, which may comprise at least the crotch region, and especially the cargo region. With this doubling, the person applying the article has a means to easily achieve the grouped form in O at the time of the application.

Alternatively, the article can be folded in any way by the manufacturer, but it includes a medium which just before the application creates the O shape or holds the O shape when it is created manually by the person applying the article . This means may be elastic characteristics, which, when in a configuration without the O-shape, are stretched, and which it contracts upon application, thus forming the O-shape, or this may be a means to fix the respective portions of the O-shape. the back sheet one to the other. One way to achieve this is by simply applying adhesive means in a conventional manner similar to the adhesives applied in feminine hygiene products such as the so-called "panty fastening adhesives" to fix the article to the wearer's panties. However, in the present case the object is not to unite the parts of the back sheet to the garments of the users, but jointly. The adhesive can be applied during manufacturing and then covered by release papers as is well known for "panty fastening adhesives". The release paper will then be removed at the time of application, just before the respective parts of the back sheet are brought together to form the configuration of O. This becomes apparent, that in the first case, packing and shipping of the article is easier, although in the second case care must be taken not to damage / deteriorate the shape during transport. Alternatively, the shape of O can be created during the manufacture of the article. In this case, such adhesive means can be applied to the article when it is flat and in an unbalanced shape, and the respective portions of the backsheet are driven together to create the grouping.

A further alternative for said O-grouping means is the use of mechanical joining means, as they are generally referred to as "mechanical fastening means", whereby a first member that is applied to a part (e.g., made of hook) is mechanically coupled to a second member (e.g., a tie-down area with loops). A still preferred alternative for fixing the respective parts of the backsheet together is not doing so in a firm manner but allowing some relative movement of the surfaces of the backsheet against each other in the longitudinal direction. This relative movement provides particular benefits during the user's movement, such as when walking. Then, the O-shaped tunnel will be a bit "distorted" without, however, losing its functionality or its general O form. This is particularly useful if the items are intended to be carried by people in motion, such as adults who move, not prostrate in bed, or crawling babies, as this will allow for increased comfort during walking. This feature can be one or more elastic bands or strips (as indicated by 240 in Figure 2a) having at least one contraction force component in the transverse direction. These can be attached to the lateral edges (ie, towards the waist regions) of the posterior leaf but not to the central part (ie, in the crotch region) of the posterior leaf, thus pulling the edges together laterals, thus forming the camber upwards or the grouping in O. Although the elastic means for the present invention do not necessarily have to be fixed to the outer edges (i.e., the lower base of the O), care must be taken to form the article in such a way that only the upper convex part of the O formed by the absorbent core is not thereby taking a complete form of W (ie having no absorbent core in the region of the side fins 225) . This can be achieved by the core having a certain rigidity in combination with the structural rigidity that results from the grouping. These elastic elements can be placed outside the back sheet, or on the inside, however these should be placed below the absorbent core member (ie, directed away from the user), since otherwise the risk of resulting in a U-shaped configuration is too high. The application of the stretching characteristics in the transverse direction has been disclosed in the European patent EP-A-0.652.175. Another preferred alternative may be to place the fastening means at some distance from the backsheet such as by a spacer or a block member, thereby forming a joint between the left and right side of the longitudinal side edges of the article. In another preferred embodiment, not only the parts of the backsheet are brought into close contact, but also to further join the total absorbent member through its total thickness. This allows the shape to be maintained better even under stress conditions in use. This union must, although being strong enough to withstand the tension in use and also when it gets wet, be soft enough not to increase the user's discomfort. Another way to achieve junctions between the backsheets, between the backsheet and the additional means to maintain and sustain the grouping into O are other well known techniques such as glue application, thermal bonding and similar I. A particularly preferred embodiment within the context of an air permeable backsheet such as a non-woven material is from the application of the application of hot air spots by means of which merging certain portions of the structure together. In a further embodiment of the present invention, the convex upwardly oriented configuration (i.e., the O shape) of the absorbent member may be supported by a separate means which creates an upwardly oriented force in the crotch region (i.e. , towards the user during use). In a first embodiment, such a lifting element can be integrated into a unitary article, such as by placing elastic elements, which have a contraction force component in the longitudinal direction of the article, on the side of the absorbent member, which is for use oriented away from the user. In this way, the elements must be at least in the crotch and / or the load area be in the area of the longitudinal center line, that is, not too far from the longitudinal center line to form the O-shape, which can be generally achieved if these are not deviated less than 2.5 cm from the center line in either the left or right direction. In a second embodiment, such a lifting element may be a separate element, which is not integral or unitary with the absorbent core element (ie, the absorbent pad). This means may be a separate garment such as a mesh brief, to be worn on an absorbent article. A particularly preferred garment for such an application is described in the present patent application, document of the lawyer CM1637Q.

This suitable garment comprises an elasticised waistband, a front panel having first and second sections, a rear panel having first and second sections, a crotch region disposed between and joining the front panel to the back panel and a pair of elasticized leg openings . The first section of the front panel has a greater resistance to stretching in the lateral direction than the second section of the front panel. The first section of the rear panel has a greater resistance to stretching in the lateral direction than the second section of the rear panel. The crotch region is provided with a longitudinal stretch control member that is disposed along the longitudinal centerline of the undergarment. The longitudinal stretch control member limits the stretching of the crotch region in the longitudinal direction by making the crotch region conforming to the skin surface of the wearer. A front stretch control member is disposed on the front panel and extends from the longitudinal stretch control member to the waistband. A rear stretch control member is arranged on the rear panel and extends from the longitudinal stretch control member to the waistband. Although suitable garment can be assembled from materials that may be known in the art as having the required mechanical properties, it is preferably woven, such that the mechanical properties of the various components thereof can be provided by a combination of fabric pattern used for a particular component and the threads used. In a particularly preferred embodiment, the longitudinal stretch control member is integrally woven with the crotch region, the front stretch control member is integrally woven with the front panel, and the back stretch control member is integrally woven with the front stretch control member. back panel. In addition, two or more of the above elements may be combined in the absorbent article. For example, a pre-bent absorbent pad can be held in place by the preferred stretchable garment, as described above. Or, a non-pre-bent pad can be brought into the O-shaped configuration by an elastic which is in an extended state during shipping, and upon occurrence the application creates an O-shaped configuration, and this pad can be retained in the place by a conventional stretchable garment, such as a brief, without a specific feature to hold the O-shape, or by a garment that bears the improved O-shape. The combination of the body adhesives with the pre-folded unit article comprising the elasticizing means oriented in the machine direction to provide a lifting force on the load zone or the crotch may also be suitable.

Lines of articulation As has been explained in the above, the transition from "convex to concave" should not be placed arbitrarily, but must happen in a desired place. This can be achieved by including a "means of articulation" in the article, and in particular in the absorbent core, if this is the most rigid element of the article. Without these additional means, this transition will generally occur a little outside the crotch region, both in the frontal direction and in the posterior region, where due to the absence of the restricting legs of the user, the shape of O can be flattened, and in this way it allows a little easier transition, which could still result in unwanted deformation or weakening of the structure. In this way, it becomes clear that it will be highly beneficial to define the transition region from the concave bending to the convex bending, which can be achieved by creating lines of articulation within the absorbent structure.

These articulation lines can be created by various means, such as cutting, or embossing (that is, creating high density lines throughout the absorbent, such that bending at the edges of these high density lines is facilitated) or low density lines (for example, created by forming the article with regions that have lower weight materials but maintaining the caliber member.) The articulation lines to increase the transition from convex to concave must extend from the outer longitudinal edges of the core. or the determining element of the stiffness of the article towards the direction of the longitudinal center line, that is to say, the articulation lines have to be arranged in such a way that they have an orientation in the transverse direction.These articulation lines can be straight lines or curves with which they allow the optimization of the specific design of the article, and the anatomy of the rupo tried of users. Also the length of the articulation lines can be easily adopted. Also, several independent lines can be used within each of the transition zones, or one line can divide into another. Preferably, the articulation lines do not run across the full width of the absorbent member, as this could result in loss of unwanted strength, or integrity, in particular during use. Since the articulation lines can be created by various means, such as cutting, or embossing, (i.e., creating high density lines through the rigid member such as the absorbent core, thereby facilitating the bending of the edges of the joint. these high density lines), or low density lines (for example, how it is achieved by creating areas of lower weight basis material in the rigid element and densifying it to a lesser degree than the surrounding regions with higher basis weight). Design capacity and final storage capacity In order to allow comparison of absorbent articles for varying end-use conditions, or articles with different sizes, it has been found that "design capacity" can be an appropriate measure. For example, babies are representing a typical group of use, but even within this group the amount of urine load, the frequency of loading, the composition of the urine, will vary widely from the smallest babies (newborn babies). to babies who crawl on one side, but also for example among the various babies who crawl individually. Another group may be older children, who still suffer from a certain form of incontinence. Also, incontinent adults can use these items, again with a broad spectrum of load conditions, usually referred to as light incontinence ranging up to severe incontinence. Consequently, these items that are able to cope with these requirements should have the ability to capture such urine amounts, which will be referred to for discussion later as "design capacity". These quantities of fluid have to be absorbed by the materials that can finally store the bodily fluids, or at least the aqueous parts thereof, so that, if any, little fluid is left on the surface of the article towards the user's skin . The term "final" refers in one respect to the situation as the absorbent article in prolonged periods of use, and in another respect to the absorbent materials that reach their "final" capacity when they reach equilibrium with their environment. This may be in an absorbent article under actual conditions of use after extended periods of use, or this may also be in a test procedure for pure materials or composite materials. If the processes under consideration have asymptotic kinetic behavior, one skilled in the art will readily consider the "final" capacities that are reached when the actual capacity has reached a value sufficiently close to the asymptotic end point., for example, related to the accuracy of the equipment measurement. Since an absorbent article may comprise materials that are primarily designed to ultimately store the fluids, and other materials that are primarily designed to fulfill other functions such as the acquisition and / or distribution of the fluid, but may still have some final storage capacity, Suitable core materials according to the present invention are described without attempting to artificially separate these functions. However, the final storage capacity for the total absorbent core can be determined, for the regions thereof, for the absorbent structures or even substructures, but also for the materials as used in any of the above. In case of applying the present invention to other articles that require different end uses, one skilled in the art will be able to easily adopt the appropriate design capabilities for other groups of intended users. In order to determine or evaluate the final design storage capacity of an absorbent article, a number of methods have been proposed. Within the context of the present invention, it was assumed, that the final storage capacity of an article is the sum of the final absorbent capacities of the individual elements or material. For these individual components, several well-established techniques can be applied as long as they are applied consistently throughout the comparison. For example, the centrifugal capacity of the tea bag as developed and well established for superabsorbent polymers can be used for these materials, but also for others (see above).

Once the capacities for the individual materials are known, the total capacity of the article can be calculated by multiplying these values (in ml / g) with the weight of the material used in the article. For materials that have a dedicated functionality other than the final storage of fluids, such as acquisition layers and the like, the final storage capacity can be neglected, since any of these materials in fact have only very low capacity values compared to the dedicated final fluid storage materials, or since these materials are intended not to be loaded with fluid, and thus must release their fluid to other final storage materials. With these definitions, for example a product so-called "pantiprotector" exhibits very low final storage capacities of a few milliliters or less. The pads for feminine hygiene often have up to about 20 ml., Articles for light urinary incontinence have for example 75 ml. to approximately 90 ml., the articles for medium urinary incontinence, or also the smaller baby diapers can have approximately 165 ml., and the baby diapers that crawl reaching 300 ml. or more, and articles for severe adult incontinence having 600 ml. or more than the final storage capacity.

Test of the centrifugal capacity of the tea bag The test of the centrifugal capacity of the tea bag measures the values of the centrifugal capacity of the tea bag, which are a measure of the retention of the liquids in the gelling material at the hydrostatic pressure.

Super-absorbent material is placed inside a "tea bag", immersed in a 0.9% by weight sodium chloride solution for 20 minutes, and then centrifuged for 3 minutes. The ratio of the liquid weight retained to the initial weight of the dry superabsorbent material is the absorption capacity of the superabsorbent material. Two liters of sodium chloride at 0.9% by weight in distilled water is poured into a tray having dimensions of 24cm x 30cm x 5cm. The height of the filling liquid should be approximately 3 cm. The bag of the tea bag has dimensions of 6.5cm, x 6.5cm and is available from a company called Teekanne in Dusseldorf, Germany. The bag is heat sealable with a standard plastic bag sealing device (eg VACUPACK2PLUS from Krups, Germany). The tea bag is opened by carefully cutting it partially, and this is then weighed. A sample of 0.200g +/- 0.005g of the superabsorbent material is placed inside the tea bag. The tea bag is then closed with a thermal sealant. This is called the sample tea bag. An empty tea bag is sealed and used as a white. Each tea bag is then held horizontally, and the sample tea bag is shaken to distribute the superabsorbent material evenly throughout the bag. The sample tea bag and white tea bag are then placed on the surface of the saline solution, and immersed for approximately 5 seconds using a spatula to allow them to completely wet (the tea bags will float on the surface of the solution saline but they are completely wet). The stopwatch is started immediately. After 20 minutes of soaking time, remove the sample tea bag and the white tea bag from the saline, and place them in a Bauknecht WS130 centrifuge, Bosch 772 NZK096 or equivalent (230 mm diameter), so that each bag sticks to the outer wall of the basket of the centrifuge. The lid of the centrifuge is closed, the centrifuge is turned on, and the speed is increased rapidly to 1, 400rpm. Once the centrifuge has been stabilized at 1, 400rpm, the timer is turned on. After 3 minutes, the centrifuge is stopped. The sample tea bag and tea bag are removed from white and weighed separately. The centrifugal capacity of the tea bag (TCC) for the sample of the superabsorbent hydrogel-forming material is calculated as follows: TCC = [(weight of the sample tea bag after centrifugation) - (weight of the tea bag of white after centrifuging) - (weight of dry superabsorbent hydrogel-forming material)] • • • (weight of dry superabsorbent material).

Claims (30)

1. An absorbent article, comprising: a top sheet, a back sheet and an absorbent core, disposed therebetween, a front and rear waist region intended to conform during use with the wearer's body in a concave shape, an area of urine load, characterized in that said article further comprises means for obtaining and / or maintaining a convex warping shape of the absorbent core oriented upwards towards the user at least for the parts of the urine loading area.

An absorbent article according to claim 1, wherein the convex warp shape of at least the urine loading zone is achieved by pre-biasing the absorbent article along the longitudinal center line of the article at least in said urine loading zone such that at least part of the backsheet covering the absorbent core is in direct contact with each other.

Absorbent article according to claim 1, further characterized in that said means for maintaining the absorbent core in the crotch region in a convex warp shape is an adhesive applied outwardly on the backsheet.

An absorbent article according to claim 3, further characterized in that said means for maintaining the core in the crotch region in a convex warp shape comprises a mechanically engaging means at least a part of which is laterally disposed away from the body. central line extending longitudinally of the article.

5. Absorbent article according to any of claims 1 to 4, further characterized in that said means for maintaining the core in the crotch region in a convex warp shape is an elastically contractible element with at least one directional force component transversely.

Absorbent article according to claim 5, further characterized in that said means is fixed to the lateral sides of the core, and is essentially not fixed at the center.

Absorbent article according to any one of claims 1 to 6, further characterized in that it has a length dimension and a width and a z direction perpendicular to both of these directions, said means for keeping the absorbent core in the loading zone urinary in a convex warp shape is an elastically contractible element with at least one directional force component in the machine direction at least exerting a directional force component in z oriented towards the user during use.

Absorbent article according to claim 7, wherein the elastically shrinkable element forms a unitary article with the absorbent pad.

9. Absorbent article according to claim 8, wherein the elastically contractible element is positioned outwardly relative to the absorbent core.

An absorbent article according to claim 7, wherein the elastically contractible element forms a non-unitary article composed of an external fixation means and an absorbent pad.

11. Absorbent article according to claim 10, wherein the external fixation means is a stretchable garment.

12. Absorbent article according to any of claims 1 to 11, further characterized in that it further comprises one or more convex-concave transition means positioned between the urine loading zone and one or both waist regions.

Absorbent article according to claim 12, further characterized in that said convex-concave transition means is one or are articulation lines.

An absorbent article according to claim 13, further characterized in that said one or more articulation lines are cuts or edges of lines of enhancement in or through the core.

15. Absorbent article according to any of claims 1 to 14, further characterized in that the urine loading zone is designed to maintain the convex grouping by at least 50 ml. of length during application and during use.

Absorbent article according to any one of claims 1 to 15, further characterized in that the article also comprises fixing means for fixing the article on the body of the user.

17. Absorbent article according to claim 16, further characterized in that said fixing means comprises tapes and tie-down areas which adhesively or mechanically fix the front and rear waist regions of the article to each other.

18. Absorbent article according to claim 16, further characterized in that said fixing means further comprise elastic members for holding the article in position.

19. Absorbent article according to any of the preceding claims, wherein said fixing means comprises an adhesive topically applied to the wearer's skin.

An absorbent article according to any of claims 1 to 19, further characterized in that the article comprises an external fixation means that is not unitary with the absorbent core.

21. Absorbent article according to claim 20, further characterized in that said external fixation means is a stretchable garment.

Absorbent article according to any of the preceding claims, further characterized in that a gap is formed during use between the urine loading zone having a convex configuration with at least one of the concavely formed waist areas, and the body of the user during use.

23. Absorbent article according to claim 22, wherein said gap is formed as a fecal sink hole which is in relation to the urine loading area located transversely deflected towards the rear.

24. Absorbent article according to claim 22, wherein the volume of said gap is minimized by having convex-concave transition means located over the limits of the urine loading zone.

25. Absorbent article according to claim 24, wherein said convex-concave transition means are located within less than 2 cm. of the urine loading area.

26. Absorbent article according to any of the preceding claims, further characterized in that the fecal sink gap is formed during use between the chassis elements extending laterally outward from the core in the crotch region and the body of the user. .

27. Absorbent article according to any of the preceding claims, further characterized in that the absorbent core has a design capacity of more than 70 ml. urine.

28. Absorbent article according to claim 27, further characterized in that the absorbent core has a design capacity of more than 90 ml. urine.

29. Absorbent article according to claim 28, further characterized in that the absorbent core has a design capacity of more than 165 ml. urine.

30. Absorbent article according to claim 29, further characterized in that the absorbent core has a design capacity of more than 300 ml. urine.