MXPA01000015A - Swellable absorbent product and a method for its manufacture - Google Patents

Abstract

An absorbent product, such as a sanitary towel, an incontinence pad or a panty liner, with an essentially elongate shape and with an upper side (11) and a lower side (12), and also having two end portions (6, 7) and a central portion (8) located between the end portions. The upper side (11) of the product has a raised portion (16) in the central portion (8). The raised portion comprises an absorbent material which can absorb on wetting. The product comprises means for controlled swelling of the raised portion (16) on wetting.

Description

ABSORBENT HYPCHABLE PRODUCT AND A METHOD FOR MANUFACTURING TECHNICAL FIELD .5 The invention relates to an absorbent product, such as a sanitary napkin, a panty-protector or an incontinence pad, such product having essentially an elongated shape in a longitudinal direction and a transverse direction, an upper side and a bottom side, and also has two end portions and a central portion located between the two end portions. The invention also relates to a method for producing an absorbent product. BACKGROUND Conventional absorbent products of the aforementioned type usually have a flat shape. Such form is suitable for transport and storage of products because flat products occupy less space than non-flat products. During use, however, a flat product tends to follow the underwear of the wearer rather than the wearer's body and the risk of leakage becomes imminent in the event that a space is formed between the l product and who uses it. Therefore, it has been proposed that the absorbent products be provided with a raised portion that fits better against the wearer's body and that results in a product that maintains contact with the body. Such solutions are described in, for example, PCT / SE97 / 01886. The raised or protruding portions may be non-absorbent so that the fluid discharged by the user is transported along or through the elevated portion. towards the absorbent parts of the product. It is more common, however, that the elevated portion contains absorbent material, so that the elevated portion can also retain fluids. Such a construction increases the total absorption capacity. lí > One problem with the construction of protruding portions of absorbent material is that the absorbent material L swells or sponges in an uncontrolled manner and can lead to the raised portion assuming a shape that is undesirable from the point of view of comfort. and 0 function, or sponge up to a height that causes discomfort for the user. An alternative, to prevent the raised portion from sponging in an uncontrolled manner, is not to use compressed, hard material or a superabsorbent mixture. In many cases, however, such a method results in the Total absorption capacity is too low. In EP-A-0 804 917 and EP-A-0 834 296, absorbent articles are described which are capable of self-molding during use. The articles comprise absorbent material 5 that expands when activated by body fluids. To facilitate expansion, an excess may be provided in the top sheet.

OBJECT OF THE INVENTION 10 An object of the invention is to remedy the problems referred to above and to construct an absorbent product that swells in a controlled manner.

BRIEF DESCRIPTION OF THE INVENTION lf 'A product of the type referred to in the introduction, in which the problems associated with the previously known products are essentially eliminated, is, according to the invention, characterized in that the product contains means for controlling the swelling with the wetting of the raised portion, said means comprise fastening points made of water-soluble material. A product according to the invention may also be characterized in that the raised portion consists of a separate piece of material. Alternatively, the elevated portion 5 constitutes a part of the absorption body of the ¿^ ^ Á ^? ^ Iü. product. According to one embodiment of the invention, the absorbent product is characterized in that a liquid-permeable surface layer is placed on the upper side of the complete product. According to another embodiment, the raised portion is surrounded by another surface layer. According to the invention, the means for controlling swelling may comprise points of attachment between the surface material and the raised portion. The means for controlling the swelling may also comprise a stretchable or expandable surface material. Alternatively, the means for controlling the swelling may comprise an excess of surface material. If the product contains a porous absorption material that is held in place by bonding areas, the means for controlling the swelling may comprise joining points: made of water-soluble material. The soluble material e :? Water can be polyvinyl alcohol. The invention also relates to a method for producing an absorbent structure which can constitute a raised portion in an absorbent product according to the invention. The method comprises the following steps: a) a strip of compressible absorption material is placed in such a way that loops of material are formed in excess in several areas of the strip, b) the strip is compressed so that the loops are essentially stamped and areas with a greater degree of compression are formed alternating with areas with a lower degree of compression, c) an elongated, narrow body is perforated the compressed strip, d) the body is arranged in a surface layer arranged in a mold with depressions, e) the surface layer is discontinuously bound with a water-soluble material to the absorption body so that an excess of surface layer is obtained between the layers. clamping areas.

DESCRIPTION OF THE INVENTION According to the invention, the aforementioned problems are solved by virtue of the fact that the elevated portion is provided with means for controlling the swelling. Such means may consist in that the absorbent material of which the elevated portion is constituted is partly compressed in limited areas. A surface material is held on the raised portion and the raised portion is fastened on the absorbent product. The fastening of the surface material to the absorbing material the elevated portion is effected in such a way that controlled swelling of the absorption material is achieved. This can be done when the surface material is joined in such a way that parts of the absorption material and the surface material are left without holding areas. When the fluid is absorbed by the absorption material, it will be allowed to swell in a controlled manner. In this case, the absorption material may be, for example, highly compressed cellulose pulp, highly compressed cotton in admixture with a binder fiber, or regenerated cellulose, such as rayon fibers. In order for the surface material to continue swelling, it is necessary that the surface material be extended or that the excess surface material be located in suitable areas. The surface material may be nonwoven and the fastener areas may consist of: for example, hot melt adhesive or welded joints. If the surface material is made of natural fibers, it is suitable to mix it with binder fibers, so that the fastening points can be formed by melting these binder fibers by supplying heat and pressure. It is also possible to create fastening points by means of ultrasound. According to a preferred embodiment, the surface material consists of cellulose-based fibers such as, for example, rayon or cotton, in admixture with polyvinyl alcohol fibers. s ^^ & ^ S ^^^ beS ^^ kJ: The means for controlling the swelling may also comprise a porous absorption material, the volume being maintained by the surface material being held on the absorption material in the holding areas. The surface material may be present in excess. The clamping areas consist of material that dissolves in wetting, the absorption material then being able to swell when the surface material is released. The absorption material can consist of a foamed material, a filling material, for example polyester wadding, or other flexible and compressible absorbent material. The fastening areas are suitably formed by adhesive material soluble in water. Mixing a water-soluble fiber in the surface material, such as polyvinyl alcohol, whose fibers are melted by the application of heat, is another method of forming bonding areas that dissolve with wetting. The raised portion may constitute an integral part L of the absorption body or consist of a separate piece of material L. It is possible to have a raised portion entirely stamped when the product is distributed, which swells to form a high portion with wetting. This is done with the hard compressed material where the raised portion will be taken. It is more advantageous, however, if the elevated portion is already present when it is delivered to the user. It is easier for the user to use the correct position of the product against the body if the raised portion is already present. With wetting, then the raised portion is allowed to swell in a controlled manner at a height and shape for the performance of its function and at the same time comfortable for the user. The raised portion is oriented in a central position transversally in the product, that is, equidistant from the long sides of the product. The raised portion may be placed approximately in the central part in the product also in the longitudinal direction, ie, equidistantly from the short sides of the product. Alternatively, however, the raised portion may be displaced from the center in the longitudinal direction, depending on the appearance of the product in other aspects. If the product has a frontal end portion with the intention of being placed on the wearer's pubis and a posterior end portion proposed to fit between the buttocks of the wearer with the short posterior side located between the buttocks of the wearer, the elevated portion It moves properly towards the back of the product. If, on the other hand, the posterior end portion is stretched so far as to extend around the wearer's buttocks and reach the place where the buttocks and the lower part of the foot are located. back, touch the elevated portion moves properly towards the front of the product. This is often the case in the construction of what is known as night towels. When the wearer is lying down, the elongated rear end portion 5 is to protect against backward runoff. As described above, the raised portion will be placed approximately at the center. The crucial factor is that the elevated portion is located in such a way that, when the product is correctly placed, it is accommodates against the wearer's vestibule to meet the menstrual fluid as soon as it leaves the body, as a result of which, the risk of run-off is reduced. It is often desirable, however, for the elevated portion to be arranged equidistantly from the long sides of the product in the central portion of the product. The construction described for the controlled swelling can of course be used in other places of the product in addition to the raised portion placed in the center. By For example, filtration barriers can be created along the short sides or long sides of the product.

BRIEF DESCRIPTION OF THE FIGURES The invention is described in more detail below with reference to the exemplified embodiments shown in the drawings. ^^ & fs ^^^^^^^^^^^^^ v & ss ^ j j &g ^^^ í ^^ fetog ¡^^ g ^^^^ ljggÜg drawings. Figure 1 shows an unused sanitary napkin, according to the invention, seen from the upper face. Figure 2 shows a longitudinal section through the sanitary napkin in Figure 1, seen from a long side. Figure 3a, a cross-section through the sanitary napkin is shown in Figure 1, seen from a short side. Figure 3b, a detail of Figure 3a is shown. Figure 3c, a cross-section through an unused sanitary napkin is shown, according to a second embodiment of the invention. Figure 4, a used sanitary napkin is shown, in accordance with Figures 1-3. Figure 5, a sanitary napkin according to a third embodiment of the invention is shown. Figure 6, a section along the line VI-VI through the sanitary napkin in Figure 5 is shown in the unused state. Figure 7 shows a section along the VI-VE line through the sanitary napkin in Figure 5 in the used state. Figure 8 shows a sanitary napkin according to a fourth embodiment of the invention, seen from ^^^^ y¡ ^^^^^^^ - ^^^^^^^ t vñ * F ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ^^ - ° ^ up. Figure 9, a section along the line IX-IX is shown through the sanitary napkin in Figure 8 in the unused state. Figure 10, a section along the line IX-IX is shown through the sanitary napkin in Figure 8 in the used state. Figure 11 shows a sanitary napkin according to a fifth embodiment of the invention, seen from above. Figure 12, a section along the line is shown XII-XII through the sanitary towel in the Figure 11 in the unused state. Figure 13 shows a section along line XII-XII through the sanitary napkin in Figure 11 in the used state. Figure 14 shows the production of a raised portion proposed for the third, fourth and fifth embodiments of the invention. Figure 15 shows the fabrication of the raised portion proposed for the third and fifth embodiments of the invention.

DETAILED DESCRIPTION OF THE FIGURES AND MODALITIES Figures 1-3a show a sanitary napkin without use :: 1, according to an embodiment of the invention. The sanitary napkin 1 has an essentially elongated or oblong shape with a longitudinal direction and a transverse direction and has two long sides 2, 3, two short sides 4, 5, two end portions 6, 7 and a central portion 8 located between the portions end, and also a longitudinal central line extended in the longitudinal direction of the sanitary napkin, as well as a transverse central line extended in the transverse direction of the sanitary napkin. A longitudinal center line means a line extended in the longitudinal direction of the sanitary napkin and located equidistantly from the long sides 2, 3 of the sanitary napkin. A transverse center line means a line located in the transverse direction of the sanitary napkin equidistantly from the short sides 4, 5 of the sanitary napkin. The sanitary napkin 1 has an upper side 11 proposed to face the wearer during use and a lower side 12 proposed to be away from the wearer during use. The sanitary napkin 1 consists of a liquid-permeable surface layer 13 arranged on the side of the sanitary napkin 1 which is available to be in front of the wearer during use, the upper side 11, and a rear layer of liquid barrier 14 arranged on the side of the sanitary napkin which is the face proposed to be away from the wearer during use, the lower side 12. An absorption body 15 is arranged between the surface layer 13 and the posterior side layer liquid barrier 14 Part of the absorption body 15 is arranged as an elevated portion 16. The raised portion 16 is arranged centrally in the longitudinal direction and transverse direction of the sanitary napkin in the central portion 8 of the sanitary napkin. The raised portion has a width at the base of about 5-10 mm and a height, calculated as the difference from other parts of the absorption body 15, which is about 5 mm. Of course, it is possible that the raised portion 16 has different heights depending on what is desired in the case in question. The dimensions suitable for protruding portions are described in the application of International Patent No. PCT / SE97 / 01886. The dimensions of the raised portion 16, according to the present invention, differ from the elevated portion described in PCT / SE97 / 01886 in that this publication describes protruding portions already formed, while a raised portion 16 according to the present invention has a first height before use and a second height when the raised portion has been activated and inflated during use. The absorption material that forms the high portion Ib Kjla? ,.? ^? ,,? :: ^ ...-, .. ^ í? ¡i is more compressed than the surrounding parts of the absorption body 15. This has been effected by partial compression of the absorption body 15. In this embodiment, the raised portion 16 and the absorption body 15 constitute a consistent unit. As a result of this construction, the raised portion 16 can swell with moisture. For the swelling to be controlled, the fastening areas 17 are in the form of welded spots arranged between the surface layer 13 and the absorption body 15. The fastening areas 17 can, of course, have another shape in addition to points. The liquid-permeable surface layer 13 and the liquid barrier layer 14 are joined together outside the contour of the absorption body in a joint 18. The joint 18 can, in a conventional manner, be an adhesive bond or a welded joint. The liquid permeable surface layer 13 is placed in a fold 19 over the central portion of the sanitary napkin having the raised portion 16. The fold 19 is intended to provide space for swelling. Figure 3b shows the fold 19 in Figure 3a in detail. Figure 2 shows a section through the sanitary napkin 1 in Figure 1 along the line II-II. On the lower side 12 of the sanitary napkin, on its liquid barrier layer 14, a holding member in the form of pressure-sensitive adhesive lines 20 is arranged parallel to the longitudinal centerline 9 of the sanitary napkin. A removable protective layer 21 is arranged over the adhesive 20. The protective layer 21 is removed by the wearer before fitting into the wearer's undergarment. Other fastener members, such as loop fasteners or friction fasteners are, of course, also possible. If the sanitary napkin 1 is physically molded in a special manner and is sufficiently rigid, the holding members can be omitted. Such product molding is described in International Patent Application No. PCT / SE97 / 01882. Figure 3a shows a cross section through the sanitary napkin in Figure 1 along the Illa-Illa line. It can be seen from the Figure that a cavity 22 is arranged between the surface layer 13 and the absorption body 15 in the area for the raised portion 16. Figure 3b shows how the possibilities of the raised portion 16 for swelling can be variable by changing the distance between points A, B and C. A is the outermost edge in the fold, B is the innermost edge in the fold and C is the junction of the surface layer 13 and the absorption body 15 in the area of the fold 19. For example, if the distance between A and C is increased, a greater possibility is obtained for the raised portion 16 to swell.

Figure 3C shows an alternative embodiment of the invention. The only difference of the already described embodiment and that shown in Figures I-3b is that Figure 3c shows a sanitary napkin in which an excess of surface material is arranged as wrinkles 23 in the upper part of the absorption body 15. Figure 4 shows a cross-section through the sanitary napkin according to the modalities in Figures 1-3 when it has been used, that is, the raised portion 16 inflated and filled all the excess volume of the surface layer. Regardless of whether the surface layer has been placed in a crease or wrinkle, the sanitary napkin 1 looks the same after swelling. After controlled swelling, the raised portion 16 has a height of about 10-20 mm, preferably about 13 mm. Figures 5-7 show a third embodiment of the invention. Figure 5 shows a sanitary napkin 1 seen from the upper face 11, Figure 6 shows a longitudinal section along the line VI-VI through the sanitary napkin 1 in Figure 5 before use and Figure 7 shows a longitudinal section through the sanitary napkin 1 in Figure 5 when it has been used, that is, moistened. Viewed from above, the sanitary napkin 1 looks a lot before and after the moistening because the raised portion 16 swells mainly in terms of height, thus only a Figure, Figure 5 shows the sanitary napkin seen from above, and therefore, Figure 5 is common for both unused products and the used one Figures 5-7 show a sanitary napkin 1 comprising a first liquid-permeable surface layer 13 arranged on that face of the sanitary napkin which is intended to face the wearer during use and a liquid barrier layer 14 arranged thereon. face of the sanitary towel proposed to be away from the user during its use. A first absorption body 15 is arranged between the first surface layer 13 and the subsequent lateral barrier layer against liquids 14. The first surface layer 13 and the first absorption body 15 are joined together by means of adhesive on all surfaces. An elevated portion 16 is arranged at the top of the first surface layer 13. The raised portion 16 comprises a second absorption body 24 and a second surface layer 25. The second absorption body 24 is bent in the second surface layer 25. The second surface layer 25 is joined at a junction 26 on the underside of the raised portion 16. The second surface cap 25 is fastened to the second absorption body 24 by means of fastening points 17. The fastening points 17 in binder fibers that are melted by means of heat application. The interconnection of the second absorption body 24 and the second surface layer 25 is described in greater detail in connection with Figure 15. The excess surface material to allow swelling of the raised portion 16 is arranged in the form of wrinkles 23 in the second surface layer 25. The fastening points 17 are arranged in such a way that the second absorption body 24 can swell in a controlled manner and fill the excess of the second surface layer 25. The raised portion 16 is arranged centrally in the longitudinal direction and the transverse direction of the sanitary napkin. The raised portion 16 has essentially the same dimensions as described above with reference to Figures 1-3. In this embodiment, the raised portion ld comprising the second absorption body and the first absorption body 15 consists of separate parts. The second absorption body 24 has been manufactured using a method in which the absorption material was molded with protruding sections which were then compressed so that the second absorption body was given a uniform thickness but variable density. When the raised portion 16 is wetted and absorbs fluids, the raised, compressed sections are raised again and impart a corrugated appearance, as shown in Figures 7, 10 and 13 to the raised portion 16. The material suitable for the second absorption body 24 is cellulose pulp fluff with high critical volume, for example, chemo-thermomechanical cellulose pulp fluff (CTMP) or carded rayon fiber. For the swelling to be controlled, the fastening areas 17 are in the form of welded spots arranged between the second surface layer 25 and the second absorption body 24. The fastening areas 17 can, of course, have another shape in addition to points. The method for manufacturing the raised portion 16 is described in more detail in relation to Figure 14. The first surface layer 13 and the liquid barrier layer 14 are bonded together outside the contour of the absorption body in a joint 18. The connection 18 it can be an adhesive bond or a welded joint. The second surface layer 25 is preferably a non-woven plastic film, but can also be a perforated plastic film or a laminate consisting of a perforated plastic film and a non-woven. The crucial factor for the choice of material is that the material is only slightly expandable. A surface layer with considerable expandable ability could break the controlled swelling in modalities comprising folded or wrinkled surface layers. The nonwoven material can be made, for example, of rayon or cotton fibers with a binder fiber, such as alcohol L . »- ¿.'r, .t» - «» i. Yii t'w. ».» Polyvinyl, in a mixture. Examples of materials suitable for the modalities with a folded or wrinkled surface layer are Novelin 380-18 made by Suominen or Thermix ES-C made by Tenotex Spa. These materials are made of non-woven bicomponent fibers, made of polyethylene and polypropylene. The first surface layer 13 can be made of any conventional material, for example perforated non-woven plastic film or a laminate consisting of a perforated and a non-woven plastic film. The first absorption body 15 is suitably made of cellulose pulp. This can originally be in the form of rolls, bales or sheets that, in the manufacture of the sanitary napkin, are defibrated dry and converted into a fluffy pulp, sometimes with the addition also of the so-called superabsorbents which are polymers with the capacity to absorb several times whether weight of water or body fluids. An alternative for this is dry molding a pulp, as described in WO 94/10956. Examples of other absorption materials that can be used are various types of natural fibers such as cotton fibers, peat or the like. Of course, it is also possible to use absorbent synthetic fibers, or mixtures of natural fibers or synthetic fibers. The absorption body 15 may also contain other components, such as dimensionally stabilizing means, liquid dispersing means or binders such as, for example, thermoplastic fibers which have been heat treated to contain short fibers and particles together as a consistent unit. It is also possible to use different types of absorbent foam material in the absorption body. Figure 7 shows a longitudinal section through a sanitary napkin according to Figure 5 which has been assigned to swell. The swelling is controlled by a combination of clamping points 17 and an excess of surface material which, together, constitute means for controlling the swelling. The second absorption body 24 now has full material in excess of the second surface layer 25. The second absorption body 24 and the raised portion 16 have a corrugated surface after swelling. Figures 8-10 show a sanitary napkin 1 according to the fourth embodiment of the invention. The embodiment is a variant of the third embodiment, the difference being that the surface layers 13, 25 have been arranged in a different manner. Figure 8 shows the sanitary napkin 1 seen from its top 11, Figure 9 shows a longitudinal section through the sanitary napkin 1 in the dry state and Figure 10 samples a longitudinal section through the sanitary napkin 1 after wetting. In Figures 9 and 10 it can be seen that the surface layer 13 is common to the absorption bodies 15 and to the second absorption body 24. The surface layer 13 is fastened to the raised portion by attachment points 17 and is fastened to the rear side layer 14 joined at a marginal junction 18 located outside the first absorption body 15. Figures 11-13 show a sanitary napkin 1 according to the fifth embodiment of the invention. The embodiment is another variant of the third embodiment, the difference being that the surface layer has been arranged in a different way again. Figure 11 shows the sanitary napkin 1 seen from above, Figure 12 shows the longitudinal section through the sanitary napkin 1 in the dry state and Figure 13 shows a longitudinal section through the sanitary napkin 1 after moistening. Figures 12 and 13 show how a first surface layer 13 is placed on the first absorption body 15 and the second absorption body 24. The first surface layer 13 is fastened to the rear side layer 14 at a marginal junction 18 located outside the first absorption body 15. A second surface layer. 25 encloses, and is fastened to the fastening points 17, to the second absorption body 24. The first surface layer ^ 5 = -fa & fa & a = < < riah »i-fc« M.? 13 covers the second surface layer 25. The junction "" of the second absorption layer 24 and the second surface layer 25 between each other is described in more detail with reference to Figure 15. Figure 14 shows the fabrication of an elevated portion. , compressed, 16 according to the invention Figure 14a shows a stripe of carded fiber 27 made of rayon, seen from above, of course the strip can be made of another material, for example, of the types already described, in relation with Figures 5-13, being suitable for the second absorption body 24. Figure 14b shows the strip of fiber 27 seen from the side Figure 14c shows the strip of fiber 27 when it has been molded into loops 28 in a Figure 14d shows the strip of fiber 27 when it has been compressed in the mold so that the areas 29 with a greater degree of compression are created in the strip of fiber 27. These areas 29 have a higher density and a greater possibility of swell or, with wetting, than the surrounding areas of low compression. A longitudinal corrugated line 31 is made in the fiber strip 27 simultaneously with the compression. Figure 14e shows the strip of fiber 27 seen from above in the compressed state. Figure 14f shows the second absorption body 24 seen from the side, when it has been partially punched out of the fiber stripe ,. A & ^ SwMilg * 8 ^^ compressed 27 in a die molding. Figure 14g shows the second absorption body 24, seen from above, when it has been punched. Figure 14h shows how, after punching, the second absorption body 24 is placed on a surface layer 25. The surface layer 25, which has been referred to earlier as the second surface layer, is a non-woven fabric made with fibers of different melting points. The fiber with the lowest melting point then constitutes what which is known as binder fiber. The surface layer 25 is placed on a mold that provides an excess of predetermined material. The second absorption body 21 is compressed in the mold and heated. By application of pressure in areas by means of an instrument, they are obtained 13 the fixing areas 17 when heat has been applied, within such areas the binder fibers are melted, the second surface layer 25 and the second absorption body 24 are then clamped together. In this way, a means has been created to control the swelling of the portion elevated. The fastening areas 17 can be in the form of, for example, dots or lines. The fastening areas 17 are now strong enough to be able to hold the surface layer 25 and the second absorption body 24 together when the absorption material is swollen. The areas clamping 17 are arranged in the low 30 areas ^^^^^ e ^^^^^^^^^^^^^^^^^ ^^^^ S ^^^^^^^^^^^^^^^^^^^^^^ ^^^^^ & ^^^^^^ ^^^^^^^^^^^^^ compression on the second absorption body 24, leaving the high compression areas 29 free to swell and fill the excess surface material and the cavities 22 located above the high compression areas. The fastening areas 17 are arranged in the transition between the areas of low compression and areas of high compression. This means that only the total absorption material is swollen upwards and not the sides. Another desirable effect of the position of the fastening areas is that the surface layer follows the absorption material when it swells and does not stretch, so that an air pocket is formed between the surface layer 25 and the absorption body 24. An air bag could produce: additionally greater difficulty in the transfer of liquids. Figure 14i shows the elevated portion seen from above. Figures 15a-e show the fold on the second surface layer 25 around the second absorption body 24. Figure 15a shows schematically how the second surface layer 25 is folded around the second absorption body 24. Figure 15b shows the same operation as in Figure 15a, but seen from the side. Figure 15c shows a side view in which: the second surface layer 25 has been folded around the second absorption body 24. Figure 15d shows how ft &, £ &* yik * -the second absorption body 24 surrounded by the second surface layer 25 is folded along the corrugated line 31 to create the raised portion 16. Figure 15e shows the elevated portion 16 seen from one of its short sides after the fold. A tool is raised below the raised portion 16 and is on the opposite side, heat is applied and the second surface layer is welded together with it on the underside of the elevated portion at a junction 26. In the fourth embodiment, shown in Figures 8-10, the surface layer 13 is the same for the first absorption body 15 and the second absorption body 24. After the steps shown in Figure 14, the surface layer 13 is attached to the side layer rear 14 in a marginal joint 18 by means of adhesive or heat. The liquid barrier layer 14, or the rear side layer, consists of a liquid impervious material. For the purpose, thin, liquid-tight plastic films are suitable, but it is also possible to use material that is originally liquid-permeable, but which has been provided with a cover of plastic, resin or other liquid-tight material. In this way, the filtration of fluid from the lower part of the absorbent product is avoided. The barrier layer 14 can, in this way, consist of any material that satisfies the ? «£ .- > * & & -a- & »s So the criterion of liquid impermeability and also be sufficiently flexible and favorable to the skin for the purpose. Examples of suitable materials for the barrier layer are plastic, non-woven and laminated films consisting of these. The plastic film can be made of, for example, polyethylene, polypropylene or polyester. Alternatively, the barrier layer may consist of a laminate made of a plastic film impermeable to the liquid against the absorption body and a non-woven facing the wearer's undergarment. This construction provides a barrier layer that is leak proof with a textile feel. The invention should not be considered as limited to the above modalities. These are intended only to explain the invention. It is possible to combine characteristics of different modalities with one another within the scope of the invention. For example, all methods described to create the excess surface material can be combined with different high portion modalities. The controlled swelling of the raised portion may also be allowed by virtue of the surface layer being extensible and fastening points being arranged at suitable locations between the surface layers and the absorption bodies. The surface layers may be extensible by virtue of the properties inherent in the material or how the surface layer, for example woven or woven, has been physically made. The elongation that occurs with the wetting in this case must be known, so that uncontrolled elongation does not take place. If a central raised portion was created, it is important that the elongation is not too large, so that the raised portion becomes uncomfortable for the user. Extendable surface layers suitable for this mode are, for example, cotton, stockinet, perforated plastic film or a laminate consisting of a perforated plastic film and a non-woven layer. A commercially available material suitable for this application is Fibrella 2000 made by Suominen. Fibrella 2000 is a ribbon of non-woven yarn made rayon fiber.

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Claims (9)

1. An absorbent product, such as a sanitary napkin, an incontinence pad or a panty-protector, such a product has essentially an elongated shape with a longitudinal direction and a transverse direction, an upper side (11) and a lower side (12), and has two terminal portions (6, 7) and a central portion (8) located between the two end portions, the upper side (11) of such product has in the central portion (8) a raised portion (16) comprising an absorbent material which can absorb with wetting, characterized in that the product comprises means for controlling the swelling of the raised portion (16) with wetting, wherein said means for controlling the swelling consist of fastening points (17) made of material soluble to water.

2. The absorbent product according to claim 1, characterized in that the raised portion (16) consists of a separate piece of material.

3. The absorbent product according to claim 2, characterized in that the liquid permeable surface layer (13) is placed on the upper side of the complete product.

4. The absorbent product according to claim 2 is characterized in that the permeable surface layer a.L liquid (25) contains the raised portion (16) and in which another surface layer (13) is placed on other parts of the upper side (11) of the product. The absorbent product according to any of claims 2, 3 or 4, characterized in that the means for controlling the swelling consists of fastening points (17) between the surface layers (13; 25) and the raised portion ( 16). 6. The absorbent product according to claim 5, characterized in that the means for controlling the swelling comprise an extensible surface layer (13; 25). 7. The absorbent product according to claim 5, characterized in that the means for controlling the swelling consist of an excess of the material of the surface layer (19; 23). 8. The absorbent product according to any of the preceding claims, characterized in that the water-soluble material is polyvinyl alcohol. A method for manufacturing an absorption structure for the formation of an elevated portion in an absorbent product according to claim 1 comprising the following steps: a) a compressible strip (27) of an absorption material is placed in such a so that the loops (28) of excess material are formed in different areas of the strip (27), b) the strip (27) is compressed so that the loops (28) are essentially stamped and areas (29) are formed with a greater degree of compression alternating with areas (30) with a lower degree of compression, c) a long, narrow body (24) is punched out of the compressed strip (27), d) the body (24) is arranged in a surface layer (25) housed in a mold with depressions, e) the surface layer (25) is discontinuously linked with a water-soluble material to the absorption body so that an excess of surface layer is obtained between the fastening areas (17) ).