ABSORBENT PRODUCT WITH PROTECTED ATTACHMENT SYSTEM

Abstract: Absorbent product such as an incontinence pad, sanitary pad or napkin, diaper or other absorbent product for absorbing body exudate, comprising (i) an attachment system associated with one or more adhesion means and designed to be adhered to and released from a user's undergarment with a release force of between 1.9 and 3 N, and (ii) a protection system releasably adhered to the back sheet of the absorbent product and which can be released with a release force of between 0.5 and 1 Newton. The adhesion means is preferably a pressure-sensitive adhesive and the surface weight of adhesive applied on the back sheet is 40 g/m<2> or lower. An easy and convenient release of the release paper from the absorbent product or of the absorbent product from the user's undergarment is thereby provided whilst still providing a secure fastening of the product with respect to a user's undergarment.

Description: Title: ABSORBENT PRODUCT WITH PROTECTED ATTACHMENT SYSTEM Field of the invention: The present invention concerns an absorbent product such as an incontinence pad, sanitary pad or napkin, diaper or other absorbent product for absorbing body exudate, comprising an attachment system associated with one or more adhesion means and designed to be adhered to and released from a surface or layer, and especially the user's underwear, and more particularly to underwear made of cotton, and a protection system having a protective strip releasably adhered to a back sheet of the absorbent product by means of the adhesive means of the attachment system. Particularly preferred for these products are pressure-sensitive adhesives. The protection system comprises m particular a protective strip, preferably made of a s licone treated material and designed to be adhered to and released from the back sheet of said disposable absorbent product. Background to the invention: Attachment systems are used to join together materials which are supposed to be associated together either permanently or temporarily. Such attachment systems may also be systems which allow re-attachment over a plurality of attachment/release cycles. In the field of disposable absorbent products, attachment systems have been employed as closure systems for diapers, absorbent garments, body coverings and the like. Such systems employ integral or multi-component materials which are joined together to function in close proximity with the user's body. In particular, such systems may be fixation systems for attaching an absorbent article to the user's undergarment . Attachment systems employed as fixation systems for disposable absorbent products with respect to the user' s undergarment have become increasingly popular in recent years. They provide a fast and convenient way of maintaining the absorbent product in a relatively fixed position with respect to the wearer's undergarment, which also helps to inhibit the movement of the absorbent product with respect to the part of the body from which the exudate is collected. They also use the user' s undergarment as a means for maintaining the absorbent product in close proximity with the user's body. In this way, a re-attachment means is provided while minimising the amount of material needed for the production of these disposable products, thus reducing production costs and avoiding material waste. Such attachment systems must of course be designed in such a way that the user is able to peel the absorbent product away from the garment whenever desired and in a convenient way. These systems commonly comprise a pressure-sensitive adhesive, usually in the form of one or more lines of adhesive applied to the outer surface or layer (e.g. the back sheet) of the absorbent product, said adhesive being optionally protected by a release paper which has to be peeled away before the product is attached to the garment. Prior art products of the aforementioned type are known for example from US-A-4701178 , US-A-4217901 and US-A-3888255. The adhesive pattern on the surface of the absorbent product usually varies from one product to another, depending on the shape, the size, or the stiffness of the absorbent product. Some problems with the use of adhesives have been addressed in the prior art. For instance, it is known that the tackiness of the adhesive applied on the absorbent product should be limited in its upper value so as to avoid adhesive residues on the garment after peeling of the absorbent product from the garment. As a matter of fact, when too high a surface weight of a highly tacky adhesive is applied, a part of the adhesive will be deposited on the garment. In extreme cases, the bond created by the adhesive is so strong that it causes damage to the garment or the absorbent product when the latter is removed. The surface weight of the adhesive applied on the absorbent product is also limited in its upper value due to the fact that an economic production must be achieved. In other respects, the adhesive should have a sufficient tackiness for maintaining the absorbent product securely in place when worn, which helps assure the wearer that the absorbent product will function correctly without leakage or the like. Furthermore, it has been found that the adhesive force of adhesives undergo an increase with respect to an associated substrate with the elapse of time (during storage for example) or a temperature change. This increase in the adhesive force causes the problem that peeling is difficult and that damage of the garment or the absorbent product may occur when the latter is removed. Solutions to these problems have been sought. In US-A- 3888255, a sanitary napkin is provided which comprises an attachment system which is a combination of a pressure- sensitive adhesive and a layer of material having a high coefficient of friction. In EP-A-0683216, pressure-sensitive adhesive compositions, tapes or sheets, more particularly designed as easily re-peelable adhesives are disclosed, which after application undergo less increase in adhesive force with the lapse of time or a temperature change. These adhesives have been defined as adhesives for which the adhesive force of the pressure-sensitive adhesive in peeling from the adhered surface is not higher than four times the initial adhesive force thereof as measured in the initial stage after application. In other respects, protection systems for adhesion means generally comprise the combination of at least two materials which are temporarily adhered together, i.e. a protective material and one or more adhesion means associated with the surface or a layer of another material. The protective material for absorbent products is generally a release tape component having a low adhesion release surface or layer. Such protection systems may also be systems which allow re- attachment over a plurality of attachment/release cycles. In the field of disposable absorbent products, such protection systems are employed for protecting the adhesives used in several different locations on such products against the adhesive becoming dirty or sticking undesirably to other objects or clothing before use. When the release strip is removed the adhesive is exposed for use. Known systems commonly comprise a pressure-sensitive adhesive in the form of one or more lines of adhesive applied to the back sheet of the absorbent product, the adhesive being protected by a release strip typically made of paper. Prior art products of the aforementioned type are known for example from US-A-4701178, US-A-4217901, US-A- 3888255 and US-A-5593750. Such attachment systems should of course be designed in such a way that the user is able to peel the release strip away from the absorbent product without requiring too great a force. When the force is too high, this can lead to tearing of the release strip during removal. When the release strip material tears, the remainder of the release strip on the adhesive often provides no leading edge which can be grasped so as to allow complete removal from the adhesive. Or, in some cases the already exposed adhesive sticks to the user' s fingers or clothing when trying to remove the remaining strip parts which can lead in the product becoming wrinkled and in most cases ruined. This often leads to the product being discarded. Similarly, too great a force can also result in removal of areas of the pressure sensitive adhesive from the back sheet, leaving thus an incomplete adhesive layer on the back sheet, which is clearly undesirable . Similarly however, the release force which the user requires to peel the release strip away from the underlying back sheet should not be too low. If the force is too low, the user is left with the impression that there is insufficient adhesive force in the exposed adhesive to maintain the absorbent product securely in place during movement. The user in such cases often discards the product believing the adhesive to be defective and unable to perform its function. Thus the opposing requirements of the peeling force between the release strip and the back sheet are apparently incompatible. Consequently products are manufactured which have a force level which is generally too high and the release strips are made sufficiently thick and strong to try to avoid tearing. This is however not only uneconomical but the problems of adhesive being torn away from the back sheet when the release strip is removed are not entirely solved. The object of the present invention is to provide a solution to the aforementioned problem. A further object of the present invention is to provide an attachment system which has the optimum adhesive force allowing an easy and convenient release of the protective strip from the back sheet of the absorbent product and allowing an easy and convenient release of the absorbent product from the user's undergarment, and at the same time avoiding the conventional drawbacks when peeling the release strip away from the absorbent product and when peeling the absorbent product from the garment, such as difficult peeling, damage of the release strip, the garment or the absorbent product, or the presence of adhesive residues on the garment, yet still providing a sufficiently high force to maintain the absorbent product securely in place. Another object of the present invention is to provide an attachment system which is not too expensive to produce, i.e. which does not make use of high amounts of materials for manufacture, and more specifically the adhesion means. A further object of the present invention is to make the attachment system independent of the adhesive type or its pattern on the absorbent product, the attachment system instead being defined by attachment force characteristics. A further object of the present invention is to make the protection ' system independent of the adhesive type, its pattern on the absorbent product, the back sheet material or the release strip material. The protection system instead should be defined by release force characteristics. One of the advantages of the present invention is therefore that any new improvement or variation of the absorbent product, in terms of its materials or the type of adhesives used, can be adopted since it is possible to adapt the attachment or protection system to meet the required release force characteristics in many different ways. For example, if all the material sheets or layers are of a predefined nature, the release force can be altered by changing the width of the adhesion surface, or its thickness. Similarly, if only the materials of the back sheet and release strip are predefined, the type of adhesion means used can be altered in addition to the width and thickness dimensions. Many other modifications of the various available parameters will be understood by the skilled man as allowing a means by which the release force ranges defined in the claims can be obtained. Once the ranges are known, the skilled man merely needs to perform simple tests to alter the materials, adhesive, patterns or dimensions of same so as to arrive at a release force within the ranges. Further problems which can be solved by this invention with respect to known prior art attachment systems for disposable absorbent products will become apparent to the reader of the following description. Summary of the invention: The prevent invention provides a solution to the aforementioned problems during release of a release strip from a back sheet of an absorbent product and during release of an absorbent product from a user's undergarment, in which said absorbent product comprises one or more adhesion means. The aforementioned object is achieved by the absorbent product comprising an attachment system and a protection system having the features defined in claim 1, whereby the attachment system comprises one or more adhesion means associated with the back sheet of said absorbent product which, when adhered to an undergarment, can thereafter be released from said undergarment, and the protection system comprises a protective strip releasably adhered by one surface thereof to the back sheet of said absorbent product by means of said one or more adhesion means, the surface weight of adhesive disposed on the back sheet being not higher than 40 g/m 2 , the release force to release said absorbent product adhered to said undergarment being between 1.9 and 3 Newtons, and the force required to release said protective strip from said back sheet being between 0.5 and 1 Newton, when measured using a pulling angle of 90°. This release force value of between 1.9 and 3 Newtons of the attachment system of the present invention was arrived at by the inventors during their extended studies performed in order to determine a solution to the opposing requirements concerning the problem of releasing of an absorbent product from a user's undergarment, taking into account that the peeling should be easy and yet at the same time avoid the presence of adhesive residues on the garment or damage of the garment or the absorbent product. Thus, a product having a release force value below 1.9 Newtons will not be satisfactory, since the adherence of this absorbent product to the wearer's undergarment will be too low and the consumer will not feel secure with such a product. On the other hand, a product characterised by a release force value above 3 Newtons will also not be satisfactory, since the adherence of this absorbent product to the wearer' s undergarment will be too high and lead to a difficult peeling and possible damage of the garment or the absorbent product when the latter is removed. The surface weight of adhesive applied on the first surface or layer is restricted to a value of 40 g/m 2 or lower since tests have shown that even above 40 g/m 2 a substantial amount of the adhesive will always be deposited on the garment. Low surface weight values of adhesive also facilitates the requirements of low costs of production which is of particular importance in disposable absorbent articles. Concerning the complementary release force characteristics of the protection system, as will be apparent, a product in which the release force is more than 1 Newton (N) will often result in one or more of the inconveniences mentioned above. Similarly a product in which the release force is less than 0.5 N will often be judged as defective. Thus, the inventors have arrived at a particularly limited range of values in which the balance of requirements mentioned above is met. Preferred embodiments of the invention are defined in the dependent claims. It should be understood that the term "adhesion means" or "adhesive" as used herein is intended to imply either a double faced adhesive tape, a tacky surface texture, or a formation on, or coating of, or treatment of, a back sheet which has the effect of increasing its adherence to a surface or layer, and especially to the user's underwear, and more particularly to underwear made of cotton, when in contact therewith. Although particular dimensions of the various components or surface weights of adhesives are specified in the following description, it will be clear to the skilled man that the width and length of the various components or the surface weights of adhesives may be changed in order to suit the particular circumstances, as long as the release force ranges are maintained. In particular, the width of the lines of adhesive means and the surface weight of adhesives may depend on the properties of the adhesive used. However, for the same adhesive means, an increase in the width of the lines of adhesive means will generally lead to an increase of the force needed to release the adhered surfaces and, for the same adhesive, an increase of the surface weight of the adhesive on the back sheet will generally lead to an increase in the adhesive force. On the other hand, the length of the lines of adhesive means only depend on the length of the surfaces or layer to be attached together and need not affect the attachment force characteristics . Brief description of the drawings: The invention will now be described in more detail with reference to the accompanying drawings in which: Fig.l illustrates a partly cut-away perspective view of a typical disposable sanitary pad in accordance with the invention, prior to use, the back sheet surface intended for placement against the garment being shown uppermost and on which three lines of pressure-sensitive adhesive are indicated, the adhesive lines being protected by a single peelable, protective strip shown in an almost fully removed position, Fig.2 illustrates a cross-sectional view taken on line II-II of the sanitary pad of Fig.l, where the cut- away portion of Fig. 1 has been reinserted so as to show the side connection of the top sheet and back sheet, and Fig.3a-d illustrates variations of adhesive surface weights and adhesive patterns in accordance with the present invention and in the case of pressure- sensitive adhesives, the values of the widths of the adhesives pattern lines, the width between two adhesive lines and the total width of the adhesive pattern being mentioned under each pattern and given in mm, the surface weight of adhesive being mentioned on the right-hand side of each pattern and given in g/m 2 . Description of preferred embodiments: The absorbent product such as an incontinence pad, sanitary pad or napkin, diaper or other absorbent product for absorbing body exudate comprises one or more adhesion means associated with the back sheet and designed to be adhered to and released from a surface or layer, and especially the user's underwear. A typical absorbent product according to the present invention having the form of a sanitary pad is shown in Fig.l and Fig.2. An absorbent product 1 of this type comprises an absorbent element 2 in the form of a generally planar pad (although sometimes arched) , which may be made up of any suitable absorbent material such as loosely associated absorbent hydrophilic material like cellulose fibres, e.g. wood pulp, regenerated cellulose or cotton fibres, which may be chemically or physically modified. The absorbent element 2 may also include other natural or synthetic materials, such as foams or polymers. The absorbent product 1 may further comprise layers of materials which are fluid permeable or fluid impermeable. A fluid permeable cover sheet 3, typically referred to as a liner or topsheet, including cellulose, regenerated cellulose, polyester or other synthetic polymers, together with polymeric fibres or films is provided on the body-facing side of the absorbent element 2, the sheet 3 being provided for comfort and comformability and directing the fluid to the underlying absorbent element. A fluid impermeable barrier material typically referred to as a back sheet 4, which has the purpose of preventing body fluid from passing through the core onto the undergarment of the ' wearer is provided on the garment-facing side of the absorbent element 2. This barrier may be any polymeric film such as polyethylene, polypropylene, or cellophane or may be a normally fluid-pervious material that has been treated to be impervious, such as a fluid repellent paper. Other fluid impermeable materials known in the art may be used. The absorbent element 2 may reside between the topsheet and the back sheet and both sheets may be advantageously joined together at their periphery. Prior art products of the aforementioned type are known for example from US-A-4701178, US-A-4217901 and US-A-3888255. An adhesive element 5 overlies a portion of the external, garment-facing surface or layer 4 of the absorbent product 1 for attaching the absorbent product 1 to an undergarment. As illustrated in the embodiment of Fig.l, the adhesive element 5 comprises three lines of longitudinally extending pressure-sensitive adhesive material. Preferably, the adhesive element 5 comprises three lines of adhesive each being 12 mm wide and separated by an 11 mm gap, the total width being 58 mm. It will be understood that the adhesion means in accordance with the present invention may have various patterns, as for example spots, squares, single full or intermittent lines or multiple full or intermittent lines, parallel or not. Other patterns are also possible. The material of the adhesion means 5 can be any of a large number of pressure-sensitive adhesives that are commercially available, including the cold, pressure-sensitive adhesives such as the acrylate adhesives, generally combined with tackifiers such as polyterpenes, or the rapid-setting thermoplastic adhesives (or hot melt adhesives) such as styrene and butadiene copolymers. Other ingredients such as fillers, antioxidants and pigments may be included. The adhesive means 5 may also comprise a double faced adhesive tape or another type of adhesive. It will also be understood that the adhesion means in accordance with the present invention may have various patterns, such as for example spots, squares, single full or intermittent lines or multiple full or intermittent lines, which may be parallel or not. Other patterns are also possible . The surface weight of adhesive disposed on the external, garment-facing surface or layer of the absorbent product 1 may vary, for example in dependence on the specific adhesive used, but will be substantially 40 g/m 2 or lower because larger amounts may provide other problems of too high adhesive forces when attached to the user's undergarment. A surface weight of between about 15 and 40 g/m 2 of adhesive will generally be used, such an amount will also allow commercially effective production. Fig.3a-d illustrates variations of adhesive surface weights and adhesive patterns in accordance with the present invention. In these examples, surface weights of adhesive from 19 to 40 g/m 2 and one, two or three line patterns with line widths from 8 to 58 mm are illustrated. The length of the adhesive pattern can be varied according to the length of the final product and does of course not affect the release force or peel strength which is necessary for peeling of the product from the surface to which it is adhered or the release force which is necessary for peeling of the release strip 6 from the back sheet 4 to which it is adhered. The adhesive 5 is protected by a peelable, protective strip 6, provided to protect the adhesive during storage and handling prior to use. Such a protective strip may be made of a paper for example that has been treated so as to be readily releasable from the adhesive element, e.g. a paper strip treated with silicone. Such protective strips are well-known in the art and do not require further explanation here . The particular properties of the release force, peel force, or peel strength of the attachment system and of the protection system are determined by the measurement of the release force using an Instron 1122, 4301 or 4464 tensile tester connected to a plotter and an integrator and using a 10 N cell. The test procedures are explained below. To ensure accuracy of results, samples must maintained during the test, in a climate chamber at 50±5% relative humidity and 23°+ 2°C. The tensile tester is first calibrated and then set up for a pulling speed of 500mm/min and a pulling length of 120 mm. The fixing length is adjusted such that the pulling angle during the test will be 90°, which is maintained due to the movable lower fixture. Measurement is effected at room temperature (23°C) and 50% relative humidity. The release force is measured in Newton (N) . For measurement of the release force of the attachment system, the absorbent product back sheet comprising the adhesion means to be tested is first adhered to a piece of panty material by using a 2 kg and 50 mm wide ETS type press roller at a speed of 1500 mm/min and in one cycle. At this stage, the adhered product may be further treated to simulate ageing or use. Details on how simulation of ageing and use treatments are made are explained hereafter. The absorbent product is then fixed to the tensile tester by way of two metal paper clamps (minimum 50 mm wide clamps, whereby the minimum width is effectively determined by the total width of the adhesive pattern on the tested sample), which are used to fix the sanitary towel to a flat fixture or sled. The testing equipment is then set to allow 90° measurement in the lower fixture thereof. The piece of panty material is attached to the upper clamp of the tensile tester. If necessary, tape may be used to extend between the tensile tester upper clamp and the piece of panty material. The angle of 90° (i.e. the pulling angle) is then checked. The test is started and the mean adhesion (release force) over a distance of 100 mm is recorded. To avoid the effects of the starting moment, the measurements after the first 10 mm are used and the test is stopped when 10 mm pulling distance remains. The test is repeated on identical samples so as to obtain the required consistency of results and to obtain a mean adhesion value, i.e. a release force value. Measurements are made of the initial release force and the release force after simulated use and/or ageing. The release force is the force required to release the first surface (or layer) comprising the associated adhesive means from the second surface (or layer) to which it is adhered. The initial release force is the release force measured at room temperature (23°C) and 50% relative humidity, within one hour after adherence. Simulated use is obtained by placing the adhered product in a heating chamber at 40°C for 4 hours ± 10 minutes, on a foam plastic sheet, the second surface or layer upwards and with a 40°C warm 1 kg weight placed on it. The sample is then left for 1 hour at room temperature (23°C) and 50% relative humidity, and the release force is measured under these conditions. Simulated ageing is obtained by placing the adhered product in an envelope and keeping it either at room temperature for 4 weeks, or in a heating chamber at 40°C for 4 weeks, or in a heating chamber at 60°C for 4 weeks. The sample is then left for 1 hour at room temperature (23°C) and 50% relative humidity, and the release force is measured under these conditions . A combination of simulated use and simulated ageing is obtained by applying a combination of the aforementioned conditions to the adhered product. For the attachment system to meet the criteria set forth in the present invention, a value for the release force of between 1.9 and 3 Newtons has to be obtained at least in test conditions in which a simulated use of 4 hours at 40°C and a simulated ageing of 4 weeks at 40°C of the sample are applied. This value is an absolute value, which must be present irrespective of parameters like the pattern or width of the adhesive. For measurement of the release force of the protection system, to ensure accuracy of results, samples must first be stored for at least 24 hours before the test. Then, the absorbent product is fixed to the tensile tester by way of two metal paper clamps (minimum 50 mm wide clamps, whereby the minimum width is effectively determined by the total width of the adhesive pattern on the tested sample), which are used to fix the sanitary towel to a flat fixture or sled. The testing equipment is then set to allow 90° measurement in the lower fixture thereof. The release strip is attached to the upper clamp of the tensile tester. If necessary, tape may be used to extend between the tensile tester upper clamp and the release strip. The angle of 90° (i.e. the pulling angle) is then checked. The test is started and the mean adhesion (release force) over a distance of 100 mm is recorded. To avoid the effects of the starting moment, the measurements after the first 10 mm are used and the test is stopped when 10 mm pulling distance remains. The test is repeated on identical samples so as to obtain the required consistency of results and to obtain a mean adhesion value, i.e. a release force value. For the protection system to meet the criteria set forth in the present invention, a value for the release force of between 0.5 and 1 N has to be obtained. This value is an absolute value, which must be present irrespective of parameters like the pattern or width of the adhesive. With the knowledge of this invention, the skilled man will therefore be able to alter the materials, width or other properties of existing products so as to produce an absorbent product comprising an attachment system and a protection system having the required release force characteristics . One example of an absorbent product in the form of a sanitary napkin fulfilling the requirements of peel force of the invention is described below. The sanitary napkin of the example has the general construction of that illustrated in Figs. 1 and 2, in which the attachment system is made of lines of a pressure- sensitive adhesive on a sanitary napkin. The surface to which the sanitary napkin is adhered and released is a panty material made of cotton. The general structure of the napkin and the back sheet material therein is very similar to the product sold by SCA Hygiene Products AB, Sweden, under the trade name Libresse Invisible Normal. The back sheet of this absorbent product is made of a 22 μm sheet of polyethylene manufactured by Trioplanex International, Sweden, under the reference ME 1148. The adhesive used is a pressure-sensitive hot melt thermoplastic type consisting of a blend of a block copolymer, synthetic resins and plasticisers and sold by Collano, Switzerland, under the trade name ECOMELT H145. The surface weight of adhesive disposed on the external, garment-facing surface of the absorbent product is 29 g/m 2 . The adhesive pattern used to fulfil the range of release force specified in the present invention comprises three lines of adhesive 12 mm wide, separated by a 11 mm gap, the total width being 58 mm. The adhesive pattern and adhesive surface weight corresponds to those illustrated in Fig. 3c. The release strip is a paper strip having a width of 64 mm and a surface weight of 48 gm "2 produced by Lohjan Paperi Oy under product code number ESP 48. The panty material made of cotton in the example is a piece of cotton manufactured by Test Fabrics, USA, under the reference Tricot Dull No. 460. The measurement of the release force of the attachment system after simulated ageing 4 weeks at 40°C and simulated use 4 hours at 40 °C has shown that this product corresponds to the criteria set forth in the present invention, which ensures 'that the peeling of the product from the user' s undergarment will be easy and convenient. Furthermore, no undesirable presence of adhesive residue on the undergarment was detected by the users which have tested this product in a real-life environment, and the adhesion force is still sufficient to provide a secure positional maintenance in the underwear. Furthermore, the measurement of the release force of this protection system has shown that this product corresponds to the criteria set forth in the present invention, which ensures that the peeling of the release strip is easy and convenient without giving the impression that there is insufficient adhesive force in the exposed adhesive to maintain the absorbent product securely in place when it is attached to the user's undergarment. Other adhesive patterns and adhesive surface weights which have been tested under the same conditions, with the same absorbent product, the same release paper, the same panty material made of cotton and with the same adhesive are illustrated by the adhesive patterns and adhesive surface weights of Figs. 3a, 3b and 3d. These products, which represent alternative embodiments according to the present invention, all gave satisfactory results when tested for their release force properties and the presence of adhesive residues on the undergarment as was tested for the above exemplified product. Although the present invention has been described with reference to several examples and embodiments showing specific products in specific arrangements and configurations, such is not to be considered limitative of the invention but merely illustrative thereof.

Claims: CLAIMS 1. Absorbent product such as an incontinence pad, sanitary pad or napkin, diaper or other absorbent product for absorbing body exudate, comprising: (i) an attachment system having one or more adhesion means associated with the back sheet of said absorbent product which, when adhered to an undergarment, can thereafter be released from said undergarment; (ii) a protection system having a protective strip releasably adhered by one surface thereof to the back sheet of said absorbent product by means of said one or more adhesion means; characterized in that the surface weight of adhesive disposed on the back sheet is not higher than 40 g/m 2 , the release force to release said absorbent product adhered to said undergarment is between 1.9 and 3 Newtons, and the force required to release said protective strip from said back sheet is between 0.5 and 1 Newton, when measured using a pulling angle of 90°. 2. Absorbent product according to claim 1, characterized in that the surface weight of adhesive disposed on the back sheet is not lower than 15 g/m 2 . 3. Absorbent product according to claim 1 or claim 2, characterized in that said adhesion means is a pressure- sensitive adhesive. . Absorbent product according to any one of claims 1 to 3, characterized in that the adhesive pattern of the adhesion means on the back sheet of the absorbent product comprises one or more lines of adhesion means of a predetermined width. 5. Absorbent product according to claim 4, characterized in that the adhesive pattern of the adhesion means on the back sheet of the absorbent product comprises three lines of adhesion means which are substantially rectangular, 12 mm wide and which are separated from one another by an 11 mm gap. 6. Absorbent product according to claim 5, characterized in that the surface weight of adhesive on the back sheet of the absorbent product is between about 26 and 32 g/m 2 . 7. Absorbent product according to claim 6, characterized in that the surface weight of adhesive on the back sheet of the absorbent product is 29 g/m 2 . 8. Absorbent product according to any one of claims 1 to 7, characterized in that the undergarment is made of cotton . 9. Absorbent product according to any one of claims 1 to 8, characterized in that said protective strip is made of paper. 10. Absorbent product according to any one of claims 1 to.9, characterized in that the protective strip is treated with silicone, at least on the surface thereof which is in contact with the adhesive. 11. Absorbent product according to any one of the preceding claims, characterized in that the protective strip covers at least the entire area of said adhesive on said back sheet.

Inventors: ANDERSSON PATRIK, BERTHOU THOMAS, ELGLUND GUNNEL, ESSLE MARIA, JOHANSSON ANETTE, KOPP KJELL-AAKE, NYBERG ANNIKA, ANDERSSON, PATRIK, BERTHOU, THOMAS, ELGLUND, GUNNEL, ESSLE, MARIA, JOHANSSON, ANETTE, KOPP, KJELL-AAKE, NYBERG, ANNIKA
Applicants: ANDERSSON PATRIK, BERTHOU THOMAS, ELGLUND GUNNEL, ESSLE MARIA, JOHANSSON ANETTE, KOPP KJELL AAKE, NYBERG ANNIKA, SCA HYGIENE PROD AB, ANDERSSON, PATRIK, BERTHOU, THOMAS, ELGLUND, GUNNEL, ESSLE, MARIA, JOHANSSON, ANETTE, KOPP, KJELL-AAKE, NYBERG, ANNIKA, SCA HYGIENE PRODUCTS AB
Application year: 1999
Main classification: A61F13
IPC codes: A61F13