MXPA00009364A - Absorbent article with a raised portion - Google Patents

Abstract

The invention relates to an absorbent article intended for female users, having such a form and size that it can principally be accommodated in the crotch part of a pair of underpants and having a longitudinal direction, a transverse direction and a thickness direction, wherein the article displays a liquid-permeable surface (2), and a liquid-impermeable surface (3), and also an absorbent core consisting of at least one absorbent body (5) arranged between the two surfaces (2, 3), and wherein a raised portion (7) extending in the longitudinal direction and displaying two end portions is arranged at the liquid-permeable surface (2) of the article. The raised portion (5) displays spacing elements (16) which during use of the article create channels (17) for the flow of liquid between the raised portion (5) and the body of the user.

Description

ABSORBENT PRODUCT WITH A HIGH PORTION TECHNICAL FIELD The invention refers to an absorbent product proposed for women, such as a sanitary towel or an incontinence protector, which has a shape and size that can be accommodated mainly in the part of the leg between a pantyhose, and that has a longitudinal direction, a transverse direction and a thickness direction, wherein the product shows a liquid-permeable surface, and a liquid impervious surface, and also an absorbent core consisting of at least one absorbent body arranged between the two surfaces, and wherein a raised portion extending in the longitudinal direction fits into the liquid-permeable surface of the article.

BACKGROUND A common problem associated with absorbent products of the type proposed herein is the leakage of body fluid beyond the longitudinal edges of the product. Such leaks are extremely undesirable since it involves a risk of soiling the user's clothes. Due to the rather non-considerable extension of the product even in the longitudinal direction, it is also not uncommon for the liquid to leak backwards or forwards beyond the extreme edges of the product. A common reason for the leakage at the edges is that the absorbent product deforms during use when the article is compressed between the thighs of the wearer. This leads to the lifting of the absorbent core of the article and its cover material. This elevation causes channels formed in an uncontrolled manner on the surface of the article, in whose channels the body fluid can not run beyond the lateral edges. Furthermore, the compression of the article gives rise to a reduction in the surface available for the uptake of the liquid, giving rise to a significant risk that the body fluid ends up on the sides of the article. Another problem related to the previously known absorbent articles is that the The lateral edges of the article, under the influence of the physical forces that arise when the wearer moves, are at risk of being bent over the liquid-permeable surface of the article. This inward fold also causes a drastic reduction in the surface available for the uptake of liquid as only a liquid permeable area, narrow, remains between the lateral edges bent inwards. One way to reduce the risk of leakage on the edges caused by the deformation of the article during use is to provide the article with a raised, preformed portion, which during use is proposed to remain against the user's genitals. In this form, the excreted body fluid can be collected as soon as it exits the wearer's body and can be immediately absorbed into the article without running out on its surface. However, a problem connected with the absorbent articles in which an elevated portion has been arranged is that the surface which the body fluid encounters initially is very limited. As a result, during dense flows of liquid it may occur that all the. liquid can not be immediately absorbed in the elevated portion. It is not comfortable for fluid to accumulate between the wearer's body and the elevated portion. When the wearer stands up or moves in another way, a space is often formed between the elevated portion and the wearer's body. If a large volume of unabsorbed liquid has been contained between the wearer's body and the surface of the article, this fluid can then flow through space. These sudden flows of liquid are extremely undesirable when the user perceives them as uncomfortable and also because they considerably increase the risk of leaks. Thus, there remains a need for a leak-proof absorbent article that works well even for large fluid flows. EP 0 804 917 discloses an absorbent article consisting of an expansion layer for extending the article to a three-dimensional structure while being worn by a wearer. The expansion layer contains incisions and openings, forming flow paths in the three-dimensional structure, that is, the elevated portion.

BRIEF DESCRIPTION OF THE INVENTION An article produced according to the invention, of the type mentioned in the introduction, is characterized mainly because the elevated portion has separating elements that, during the use of the article, create channels for the liquid flow between the portion elevated and the body of a user. The separating elements can be made before use or they can be made in such a way that they do not appear until after moistening. One way to produce the separating elements that are activated with wetting is by forming a hillock with the raised portions and then compressing the small one so that a practically smooth surface is obtained. When the hillock becomes wet and absorbs liquid, the raised, compressed portions will rise again and form the separating elements on the surface of the hillock. Suitable materials for obtaining the desired effect are fluffy cellulose pulp with high crucial volume, for example, thermo-mechanical cellulose fluff pulp, chemical pulp (CTMP), absorbent foam material and other materials that maintain compression prior to wetting. The compressed structure can be agglomerated with a water-soluble binder to maintain compression before wetting. Providing the raised portion of the article with spacing elements means that the raised portion will not seal against the wearer's body. This eliminates the risk that fluid that has not had time to be absorbed by the elevated portion is enclosed between the elevated portion and the user's genitals. Instead, the liquid can flow into the channels that form between the separating elements and can be absorbed by the side portions of the raised portion or in the absorption material arranged at the base of the elevated portion. The spacer elements may be in the form of raised ridges, sunken channels or grooves or a plurality of protrusions of the raised portion. These projections may have any convenient shape but, for reasons of convenience, they must present a rounded surface towards the user of the article. If the spacer elements are in the form of ridges or channels, these preferably should extend mainly in the transverse direction of the article. Accordingly, a raised portion may have both raised ridges and sunken channels, or ridges and projections, and so on. The separating elements may be formed integrally with the raised portion or may consist of tapes, bands or the like of the absorbent or non-absorbent material that has been applied to the raised portion. The spacer elements may be part of a forming element that gives shape stability to the raised portion. It is an advantage if the elevated portion is stable in the wet and dry conditions, since it is thus possible in each situation to predict the shape of the elevated portion. Being stable in shape implies that the elevated portion during normal use will remain practically unaffected and will not deform when subjected to pressure and shear forces that arise during use. In addition, the shape of the raised portion should not be appreciably modified during the absorption of body fluid. An absorbent article with a raised portion that resists deformation when subjected to pressure during use is described in WO 98/22062. In addition, absorbent materials having substantially the same volume in wet and dry conditions are described in WO 98/222059. Another way of obtaining a stable raised portion in its form is when the raised portion contains a forming element. Such a forming element advantageously consists of a rigid plastic material. According to one embodiment of the invention, raised marginal barriers are arranged along the lateral edges of the article. According to another modality, a layer of camouflage is arranged between the liquid permeable cover layer and the separating elements in the raised portion to hide the separating elements. Such a camouflage layer can be a very porous fiber layer that does not impede the flow of liquid in the channels between the separating elements. Otherwise, the camouflage layer may be formed of material that collapses when wetted, by this means the raised portion of the article during and after use has a relief structure that is observed from the surface. Examples of the materials that can be used for the camouflage or masking of the separating elements are viscose fibers, hydrophilized polypropylene cotton or mixtures thereof. To prevent the raised portion from causing discomfort in the form of chafing or pressure during use, but instead providing good body contact so that excreted body fluid can be collected as soon as it leaves the wearer's body, it is essential that the Elevated portion has an anatomically correct shape. A hard, stable hillock in its shape, which is mainly not affected by the forces that occur during use, should not, therefore, be too high to press against the user's body and thus cause discomfort during use. In addition, it is necessary to ensure that the raised portion does not rub the soft, sensitive parts in the wearer's crotch. It has been shown that the raised portion that protrudes at least 5 inm, but not more than 20 mm, from the surface of the article in the upper part meets the requirements of good body contact and greater comfort for the wearer. Correspondingly, a stable hillock should be relatively narrow, conveniently between 2 mm and 25 mm at the base and preferably between 12 mm and 16 mm. The hillock is conveniently formed with a mainly triangular cross-section and, consequently, is wider at the base than the upper part. As the hillock becomes relatively narrow, it may, without disturbing the wearer, protrude something between the wearer's lips, an advantage if the lug somewhat separates the lips as this facilitates the transfer of the user's liquid to the article.

The raised portion must have such a shape on its back that it makes contact against the wearer's body in the area behind the vaginal orifice. In this way the body fluid is prevented from running backwards in the area between the wearer's buttocks and leaking out of the article. Such a backward leak is especially problematic when the user is lying down. In a corresponding manner, the front part of the raised portion must connect against the bodily form of the wearer in the area facing the vaginal orifice. To connect against the user's anatomy, the elevated portion must be higher in this part of the article that is proposed will be against the vaginal orifice of the user. From the highest part, the height should gradually decrease in a direction towards the end portions of the article. The raised portion should extend backwards from the highest part between 5 mm and 40 mm and, preferably, between 10 mm and 30 mm. In front of the highest part, the elevated portion should have a length between 30 mm and 90 mm, preferably between 55 mm and 80 mm. The elevated portion conveniently has a total length that is between 40 mm and 140 mm in the longitudinal direction of the article and preferably between 70 mm and 120 mm. A raised marginal barrier may conveniently be arranged on both sides of the central raised portion. Marginal barriers increase security against leakage of the item by serving as seals against the wearer's groin. The high marginal barriers can occur in different ways. Examples of side barriers that commonly occur are elastic side edges, foam rubber strips, wadding or the like. Marginal barriers can be purely physical barriers or can prevent the passage of liquid by absorbing body fluid.

BRIEF DESCRIPTION OF THE FIGURES The invention will be described below in detail with reference to the figures shown in the attached drawings, in which: Figure 1 shows a plan view of a sanitary towel according to the invention, seen from the side facing the wearer during use, Figure 2 shows a view in longitudinal section along the line II-II through the sanitary towel in Figure 1, Figure 3 shows a plan view of a towel hygienic according to a second embodiment of the invention, seen from the side facing the wearer during use, and Figure 4 shows a forming element for stabilizing a raised portion, observed from the side that is proposed facing the wearer during the use.

DESCRIPTION OF THE MODALITIES The sanitary towel 1 shown in Figures 1 and 2 consists of a liquid-permeable cover layer 2 arranged on the side of the sanitary napkin 1 which is intended to be in front of the wearer during use. The liquid-permeable cover layer 2 conveniently consists of a soft, skin-friendly material. Examples of liquid-permeable cover materials that can be used are the different types of non-woven fabrics, known as nonwovens. Other existing liquid permeable cover materials are perforated plastic films, nets, knitted or woven fabrics and combinations and laminates of the aforementioned types of materials. The sanitary towel 1 further consists of a liquid impervious cover layer 3 arranged on the side of the sanitary napkin 1 which is proposed for the side away from the wearer during use. A thin plastic film is normally used as a liquid impervious cover 3. However, it is also possible to use layers of liquid permeable materials coated with liquid impervious material. Other treatments, such as hot pressing, to melt an initially permeable material for a layer that is mainly impermeable to liquids, it can also be used. It is also possible to use a non-woven material, or other textiles that are so dense and the fibers of which are so hydrophobic that they can function as a liquid barrier layer. The two cover layers 2, 3 mutually join and form a joining edge, projection 4 around the periphery of the sanitary towel. The joint between the cover layers 2, 3 can be made using any known technique suitable for the purpose, such as gluing, welding or sewing. The two cover layers 2, 3 enclose between them a first absorbent body 5, and a second absorbent body 6. The first absorbent body 5 forms a raised, elongated portion 7 on the surface of the sanitary towel that is proposed to cope with the user during use. The second absorbent body 6 is arranged between the first absorbent body 5 and the covered layer impervious to liquids 3 and has mainly the same shape as the sanitary towel in its entirety. One purpose of the second absorbent body 6 is to collect any body fluid that is not absorbed by the first absorbent body 5. Therefore, in the embodiment shown, the second absorbent body 6 is not intended to receive large amounts of liquid and therefore may be composed of, for example, one or several layers of a suitable absorbent material such as fluffy cellulose pulp, absorbent nonwoven, tissue, foam or the like. Another purpose of the second absorbent body 6 is to give the sanitary towel a certain stability. According to an alternative embodiment, the first absorbent body 5 can be formed of liquid-receiving material and transport it to the second absorbent body 6, which in such embodiment has a greater absorption capacity than the first absorbent body 5 and thus can function as the main absorbent body in the sanitary towel. The materials suitable for the first absorbent body are then fiber materials with low absorptive capacity but high pick up capacity and liquid permeability. The second absorbent body may conveniently contain absorbent fiber materials, for example, fluff pulp of cellulose, superabsorbent polymers or the like. In order to achieve good retention of the shape in the raised portion 7, the portion may comprise a shape stabilizing body, for example, of the type described in WO 98/22060. Other types of shape stabilizing bodies can also be used. Examples of other embodiments of shape stabilizing bodies are shown in Figures 3 and The sanitary napkin 1 has a trapezoidal shape with a wider front portion 8, a narrower rear portion 9 and an intermediate crotch portion 10. The sanitary napkin 1 further shows two longitudinal side edges 11, 12 and two end edges 13, 14 The longitudinal raised portion 7 is wider and higher in the crotch portion 10 of the sanitary napkin and becomes narrower toward the front portion 8 and the back portion 9, respectively. A connecting element 15 in the form of a rectangular, longitudinal area of self-adhesive sizing is arranged on the surface of the liquid-impermeable cover layer 3 which is remote from the wearer. The connecting element 15 extends over most of the surface of the liquid impervious cover layer 3 between the two end edges 13, 14. Of course, it is possible to use other gluing patterns, such as longitudinal strips, areas cross-sections, points, circles, or other figures. The invention is not limited to the adhesive bonding bodies; friction joints and other types of mechanical joining devices, such as snaps, fasteners, belts, pants or the like may be used if appropriate. The first absorbent body 5 forms, as already established, a raised central portion 7. Due to the shape of the sanitary towel with the raised central portion 7, the sanitary towel is kept in contact with the wearer's body during use. Therefore, the liquid that is immediately excreted is collected in the elevated portion 7 and can be absorbed by the first absorbent body 5. As the first absorbent body 5 is proposed to receive and absorb almost all the body fluid emitted, the capacity of The absorption of the first absorbent body 5 must correspond to the total amount of the liquid that the sanitary napkin is expected to absorb during use. However, it can happen that a large amount of liquid is removed for a relatively short period of time and the absorption speed of the first absorbent body 5 is not sufficient for all the liquid to be immediately absorbed through the relatively small surface of the liquid. the raised portion 7 which is initially wetted by the liquid. In order to prevent the liquid from coming together between the body of the wearer and the raised portion 7, the raised portion 7 is therefore provided with spacer elements 16 in the form of transverse raised ridges, which between them define channels 17 for the collection and transport of excess liquid. In addition, a sunken channel 18, 19 is arranged at each end of the raised portion. The first absorbent body 5 is preferably formed of a material that does not collapse during use and that preferably retains its shape even after wetting. The fiber materials described in WO 98/10953 and WO 94/10956 are examples of suitable absorbent materials. These materials have high absorption capacity and a great capacity to withstand deformation during use. Other materials that may be used are different types of foam, fluff pulp of traditional cellulose, fiber batt and the like. In addition, the first absorbent body 5 may consist of a highly absorbent polymeric material, commonly known as superabsorbents. It is also possible to use different combinations of materials. The material combinations described in WO 98/22059 are particularly convenient. The separator elements 16 may be visually perceived as uncomfortable or may give the sanitary napkin a less attractive appearance. The sanitary towel shown in Figures 1 and 2 is therefore provided with a camouflage layer 20 which is arranged between the first absorbent body 5 and the liquid-permeable cover layer 2. The camouflage layer 20 conveniently consists of a layer of porous wadding or loose fibers that collapse when wet. Before using the hygienic towel, the masked hillock 7 shows a practically smooth surface. When the raised portion 7 is moistened with the body fluid, the camouflage layer 20 collapses, whereby the channels 17 between the spacer elements 16 and the front and rear channels 18, 19 in the raised portion are activated to receive and transport temporarily more dense flows of liquid. Examples of materials that have been found convenient as camouflage layers are hydrophilic fibers such as viscose, cotton, cellulose pulp, hydrophilized polypropylene fibers or different types of blends. The layers of soft, compressible fibers that have large pores and can quickly let the liquid penetrate, but not necessarily collapse with moisture can also be used. The camouflage layer 20 is not important for the invention and can be excluded. Another example of a sanitary napkin 300 according to the invention is shown in Figure 3. The sanitary napkin 300 is composed of a liquid permeable cover layer 302, a liquid impervious cover layer 303 and an absorbent body composed of two. parts 305, 306 contained between the cover layer 302, 303. A first absorbent body 305 forms a raised portion 307 on the side of the sanitary napkin 300 which is intended to be facing the wearer during use. A second absorbent body 306 is arranged between the first absorbent body 305 and the liquid impervious cover 303 and is intended to receive excess liquid that can run outwardly from the first absorbent body 305. The sanitary towel 300 is in the shape of a watch. sand, with wider end portions 308, 309 and a narrower central portion 310 and shows longitudinal side edges 311, 312 and transverse end edges 313, 314. To achieve stability in the shape in the raised portion 307 a first absorbent body 305 is arranged within a rigid cover 321, for example, of plastic. The cover is formed with a plurality of protruding spacer elements 316 in the form of knobs with a rounded surface, which between themselves define channels 317 for the flow of the liquid. To allow the liquid to pass into the absorbent body 305 within the cover 321, the cover 321 is provided with a plurality of perforations 322. In Figure 3, the cover 321 projects through the liquid-permeable cover layer 302. otherwise, the cover 321 can, of course, be covered by the liquid permeable cover layer. By using a special stabilizing element for the raised portion 307, the first absorbent body 305 can be formed of any absorbent material with suitable absorption qualities, regardless of the stability of the shape of the material. Accordingly, it is possible to use soft fiber structures of synthetic or natural fibers with or without the addition of superabsorbent material. Another advantage of forming the raised portion 307 of a liquid-resistant material, such as a plastic, is that the raised portion 307 has a well-defined shape and size under all conditions of use. The sanitary napkin shown in Figure 3 further comprises elastic elements 323, 324, which are arranged along the longitudinal side edges 311, 312 of the sanitary napkin. The elastic elements 323, 324 are applied in a pre-elongated state, preferably at the junction of the edges 304 between the two cover layers 302, 303, for example, by gluing or welding. Due to the fact that the elastic elements 323, 324 pull the material along the side edges 311, 312 of the sanitary napkin, the sanitary napkin is curved in the longitudinal direction, at the same time that the side edges rise to form lateral barriers against leaks. The common types of elastic elements for this purpose are threads, bands or similar. Otherwise, the elastic elements 323, 324 may be applied on the outside of one of the cover layers 302, 303. The elastic elements may then be composed of, for example, elastic bands that bend around the lateral edges 311 , 312 of the hygienic towel. As shown in the Figure, the elastic elements 323, 324 extend only over a central part of each lateral edge 311, 312. Otherwise, it is of course possible to arrange the elastic elements along all or a large part of the lateral edges. Although the sanitary napkin shown in Figure 3 is not provided with a camouflage layer of the type described in connection with the sanitary napkin in Figures 1 and 2, it is also possible to provide the sanitary napkin in Figure 3 with such a camouflage layer. Figure 4 shows a forming element 421 that can be used to obtain shape stability in a raised portion that does not have sufficient shape stability per se. The forming element 421 is arranged on that surface of the absorbent article that is intended to be in front of the wearer during use. To clearly show the appearance of the forming element, no liquid-permeable covered layer has been drawn in the figure. However, it is advantageous if a covered layer is arranged on the forming element 421 and the raised portion 407 is inside. The forming element 421 is conveniently formed of a rigid plastic material that has been formed for appearance as shown in Figure 4. Naturally, it is possible to use other materials such as cardboard or metal. The forming element shown gives stability to the raised portion 407 but, due to the skeletal construction of the forming element 421, the flow of the liquid to the raised portion 407 is not prevented to any appreciable extent. In addition, the forming element serves as spacer elements 416 which create channels 417 for the flow of liquid between the raised portion 407 and the body of a user. The invention has been described in the above in connection with sanitary napkins. However, it is also possible to use the invention with other absorbent articles that are proposed for use by women. Accordingly, the invention also includes pantiprotectors and incontinence guards for women.

Claims (12)

1. An absorbent article proposed for women, such as a sanitary napkin or an incontinence protector, having a shape and size that can be accommodated mainly in the crotch of a pant and having a longitudinal direction, a transverse direction and a direction in the thickness, wherein the article shows a liquid-permeable layer (2), and a liquid-impermeable layer (3), two longitudinal side edges (11, 12), two transverse end edges (13, 14) and also a absorbent core consisting of at least one absorbent body (5) arranged between the two layers (2, 3), and wherein a raised portion (7) extending in the longitudinal direction and showing two end portions is arranged in the liquid-permeable layer (2) of the article, characterized in that the raised portion (7) contains spacing elements (16) and between which the separating elements (16) channels (17) are formed in the su the surface of the raised portion (7) whose channels (17) extend mainly in the transverse direction of the article, and whose channels (17) allow the flow of liquid in the direction towards the lateral edges (11, 12) of the article.

2. The article according to claim 1, characterized in that the separating elements (16) only appear after moistening.

3. The article according to claim 1 or 2, characterized in that the separating elements (16) consist of the raised rims, extending mainly in the transverse direction of the article.

4. The article according to claim 1, 2 or 3, characterized in that the separating elements (16) comprise at least one channel (18, 19).

5. The article according to claim 4, characterized in that it contains a channel (18, 19) which is arranged in the end portion of the elevated portion (7) and extends mainly in the longitudinal direction of the article.

6. The article according to claim 1 or 2, characterized in that the separators (316) are constituted by knobs (316) projecting from the elevated portion (307).

7. The article according to any of the preceding claims, characterized in that the raised portion (307, 407) comprises a stabilizing element (321, 421).

8. The article according to claim 7, characterized in that the stabilizing element (321, 421) comprises rigid plastic material.

9. The article according to any of the preceding claims, characterized in that the elastic elements (323, 324) are arranged along the lateral edges (311, 312) of the article, which elevate the lateral edges to form barriers against leaks , lateral.

10. The article according to any of the preceding claims, characterized in that the camouflage layer 20 is arranged between the liquid-permeable cover layer (2) and the separating elements (16) in the raised portion (7).

11. The article according to claim 10, characterized in that the camouflage layer, mainly consists of hydrophilic fibers that collapse with wetting.

12. The article according to any of the preceding claims, characterized in that the raised portion (7; 307) is between 40 mm and 140 mm in the longitudinal direction of the article and, preferably between 70 mm and 120 mm.