MXPA06007161A - Absorbent article and method for manufacturing absorbent article - Google Patents

Abstract

The present invention relates to a an absorbent article (1) such as sanitary towel, diaper, incontinence protector or panty liner, which article (1) has a substantially elongate shape with a longitudinal direction and a transverse direction and has two side edges (9, 10), a front edge (11) and a rear edge (12=a front portion (6), a rear portion (7), and a middle portion (8) located between the front portion (6) and the rear portion (7), which article (1) moreover comprises a shaping element (4). According to the invention, said shaping element (4) comprises at least two substantially elongate blanks (4a, 4b) which are cross-laid in an at least partially overlapping and substantially X-shaped configuration. The invention also relates to a method for manufacturing an absorbent article. The invention permits improved manufacture of said article, with less material wastage.

Description

Published: - with intemational search report For two-letter codes and olher abbreviations, refer to the "Guid No ofeach regular issue of the PCT Gazette.

ABSORBENT ARTICLE AND METHOD TO MANUFACTURE THIS ABSORBENT ARTICLE TECHNICAL FIELD The present invention relates to an absorbent article, such as a sanitary napkin, incontinence protector or panty liner, this article has a substantially elongated configuration, with a longitudinal direction and a transverse direction, and has two side edges , a front edge and a trailing edge, a front portion, a back portion and a middle portion, which is positioned between the front portion and the back portion, this article, likewise, comprises a configuration element. The invention also relates to a method for manufacturing an absorbent article, such as a sanitary napkin, a diaper, an incontinence protector or panty liner, this article having a substantially elongated configuration, with a longitudinal direction and a transverse direction, and It has two side edges, a front edge and a trailing edge, a front portion, a back portion and a middle portion, located between the front portion and rear portion, and also a configuration element.

PREVIOUS TECHNIQUE In relation to absorbent articles, such as, for example, diapers, diaper pants, adult incontinence guards, sanitary napkins and panty liners, there is a general requirement to provide materials and structures that are capable of collecting, distributing and absorb the excretions of the body, in a fast and effective way. Current absorbent articles generally provide good absorption with low risk of leakage, and a high degree of comfort for the person using this absorbent article. An absorbent article, previously known, in the form of a sanitary napkin, is composed of a first cover sheet, which constitutes a top sheet, permeable to liquid, a second cover sheet, which constitutes a bottom sheet, impervious to liquid , and an absorption body, placed between the previous ones. The article can readily be configured into an approximate cup shape, to adapt to the female anatomy and to provide good contact against the wearer's body, to give an improved fit and fluid absorption capacity, Current sanitary napkins are also provided with a long, narrow longitudinal lift, which extends upwards from the surface of the article. A sanitary towel can also be designed with an increased amount of absorption material in the area where the liquid is expected to be excreted. An absorbent article, of known type, is described in WO 01/45637 and is designed with a substantially elongated configuration, which defines a longitudinal direction and a transverse direction. The article comprises two side edges, a front edge and a trailing edge, a front portion and a back portion, and a middle portion, positioned between the front portion and the back portion. The known article further comprises a top sheet, permeable to liquid, a bottom sheet, impervious to liquid, and an absorbent core. According to WO 02/45637, the absorbent core is designed with two "legs", which are at a specific angle in relation to each other. Arranged between these "legs" is an elastic element, which causes a ridge-like elevation that is formed between these two legs. It can also be noted that a sanitary napkin is a mass-produced article, which is manufactured in very large quantities,. and there are still increasing demands regarding low manufacturing cost, low material consumption and little waste of material, combining with high quality and improved function, at least with respect to the absorbent core of the article. The patent document US 4 216 773, has already described a method for manufacturing diapers, in which a substantially rectangular absorption body is divided into a pattern defining fold lines, which form fins. These fins are then bent in the form of an overlap, through the middle part of the absorption body. In this way, a thicker section of material is obtained in the middle part of the diaper in question, by means of a simple and cost-effective manufacturing process. Although the known types of absorbent articles, described above, can be considered as having a satisfactory function, it can be pointed out that there is still a problem in the form of increasing demands for more simplified manufacturing methods, which allow for less material waste and lower costs. of manufacture, in combination with a manufacturing process for the absorbent core.

EXHIBITION OF THE INVENTION A main object of the present invention is to make available an improved absorbent article and an improved method for the manufacture of an absorbent article, in which the aforementioned problems are solved. The object is achieved with an article of the type mentioned in the introduction, which is characterized in that the configuration element comprises at least two substantially elongated preforms, which are crossed in an overlap, at least particularly, and a configuration substantially in X. The object is also achieved with a method, of the type mentioned in the introduction, which is characterized in that it also comprises producing at least two preforms, substantially elongated, which construct said configuration element and these preforms are placed transversely at least a partial overlap and a substantially X-shaped configuration. The invention provides certain advantages. In particular, it can be mentioned that the article, according to the invention, can be manufactured with a very small amount of material waste, which, in turn, provides lower production costs and less expensive products, compared to the technique previous.

BRIEF DESCRIPTION OF THE FIGURES The invention will now be described with reference to a preferred embodiment and the accompanying drawings, in which: Figure 1 shows a plan view of the absorbent article, according to the invention; Figure 2 is a plan view of an absorbent core, which is to be used in the invention; Figure 3 shows a cross-sectional view, according to Figure 1, along the line III-III in Figure 1; and Figure 4 shows a plan view of an absorbent core, according to an alternative embodiment of the invention.

PREFERRED MODE An absorbent article 1, according to the present invention, is shown in a plan view in Figure 1. This article 1, according to the embodiment shown, comprises a first cover sheet, in the form of a sheet upper 2, permeable to liquid, which is disposed on that surface of article 1 that attempts to be directed towards the user during use. Article 1 it also comprises a second cover sheet, in the form of a bottom impervious to liquid, which is arranged on that face of article 1 which attempts to be directed away from the user, during its use. The article 1 also comprises an absorbent core 4, disposed between the upper sheet 2 and the bottom sheet 3. The absorbent core 4 is made conveniently of fiber sheet, preferably a sheet of strongly compressed fiber. Suitable alternative materials are absorbent foam materials, sheets made of cellulose hair pulp, wadding material and other absorbent materials of known types, which are suitable for use in, for example, sanitary napkins, diapers for children , incontinence protectors and panty liners. The upper sheet 2 and the bottom sheet 3 are joined together to the outside of the absorbent core 4 and along the periphery of the article 1, for example by rubber, sewing, welding or some other suitable method of joining, so that it forms the peripheral edge 5. The absorbent article 1 is substantially long and narrow and may comprise a front portion 6, directed towards the user during use, and a rear portion 7, directed backwards on the user, during use. Article 1 additionally comprises an intermediate portion 8, relatively narrow, which is placed in a position that corresponds to the groin area of a user. The article 1 also has two curved side edges 8, 19, a convex curved front edge 11 and a convex curved rear edge 12. The division of the absorbent article 1 into a front portion 6, a rear portion 7 and a middle portion 8, not it should be understood as meaning that there are narrowly defined lines or edges between the different portions 6, 7, 8 and this first attempts to clearly explain the function of these different parts during the use of the article 1, the portions 6, 7 and 8 are placed in different positions in relation to the body of the user. The transitions between the front portion 6 and the middle portion 8, and between the middle portion 8 and the rear portion 7, are thus not placed in exact predetermined boundary lines, but rather within the transition areas, which are placed around one third of the way down the length of the article 1, calculated from the front edge 11 and the trailing edge 12, respectively. It can thus be pointed out that the middle portion 7 constitutes that part of article 1, which, during use, is intended to admit and absorb most of the liquid excreted by the user to the absorbent body 1.

This absorbent body 4 defines a configuration element, which, according to the embodiment shown, constitutes an absorbent core, which, in turn, is composed of two separate core preforms 4a, 4b, as can be seen from FIG. Figure 1. The preforms of the core, 4a, 4b are positioned in such a way that they form a substantially X-configuration between the bottom sheet 3 and the top sheet 2, that is, so that the core preforms 4a, 4b are place crossed as they overlap, at least partially with each other. In the manufacture of article 1 the two preforms of the core 4a, 4b are thus arranged in the desired X configuration, after which they can be fixed together with other sheets 12, 3 included in article 1. The absorption body The resultant will thus have the appearance shown separately in Figure 2, ie with a width a in the front portion 6, which exceeds the width b in the middle portion 8. In the area where the two core preforms 4a, 4b overlap between yes, the absorption body 4 will also have a thickness corresponding approximately twice the thickness of each separate core preform, 4a, 4b. The core preforms, 4a, 4b also define two "legs" 13, 14 in the rear portion 7 of the article absorbent 1. These legs extend backward and define a predetermined angle a between the legs 13, 14. The selection of the angle a and also the length of each leg 13, 14 (ie, calculated from an imaginary point of intersection between the legs 13.1 4) can be adapted to the requirements with respect to, for example, the fit and the ability to absorb liquid from the article, i.e., how these properties are controlled by the placement and sizing of the absorbent material in the absorption body 4 . The angle a is preferably between 10 and 120 °, preferably between 15 and 40 °, and the length of each leg, calculated from said point of intellection, is between 20 and 350 mm, preferably between 50 and 150 mm. As can be seen from Figure 2, the absorbent article 1, according to the described embodiment of the invention, is designed with a front portion 6, which is wider than the middle portion 8, and with a middle portion 8, which is narrower than both the frontal portion and the posterior portion. To obtain an absorbent article, which has a good fit and is comfortable for the user, it is necessary that the sanitary napkin has a configuration which, to a greater degree, adapts to the user's anatomy. It is thus particularly important that the width b of the absorption body 4, at least in the part front of the middle portion 8, do not exceed about 40 mm. One reason why the front portion 6 is wider than the middle portion 8, is that this wider front portion 6, together with the narrower middle portion 8, are themselves configured around the wearer's body and the absorbent article. 1 to a certain extent "hooks" against the wearer's legs, thus making it possible for the absorbent article to remain in place against the wearer's body. The front portion 6, slightly wider, is preferably presented in a slightly oval configuration. One reason for this is that, when used, it is curved to the interior with a cup-shaped configuration, that is, the fold up of the portion front 5, relative to the middle portion 8, does not take place along a sharp fold line, and instead, the curvature is continuous in the longitudinal direction of the absorbent article. In this way, the front portion 6 forms a moderately rounded cup, which adapts well to the user's anatomy. In addition, the oval configuration of the front portion 6 also gives a large absorption area and a large volume for the absorption body 4. Referring to Figure 1, it will be noted that the absorbent article 1 is oriented in one direction longitudinal, which is defined by a central line 15. Article 1 also has two longitudinal side edges 9, 10, a curved front edge in a connected, transverse, 11, and a trailing edge 12, curved convex, transverse. The absorbent article is designed in such a way that the front part of the middle portion is on a first transverse line 16, which extends in the transverse direction of the absorbent article and cuts through the side edges 9, 10 of the absorbent article. In the first transverse line 16, the side edges, 9, 10, change the inclination in relation to the longitudinal center line 15, as a result of which the width of the absorbent article increases in the direction towards the front edge 11. In this way , the front portion 6 has a maximum width exceeding the width of the middle portion 8 on the first transverse line 16. The maximum width of the front portion 6 is favorably at least 1.5 times the width of the middle portion 8 on the first line transverse 16. The inclination of the lateral edges, 8, 9, in the frontal portion 5, is defined by the angle β between each respective lateral edge 9, 10, and a longitudinal line, which is parallel to the central line 15, as a result of which the angle ß is between 30 and 90 degrees and the width of the middle portion of the The absorption body 4 in the first transverse line 15 is between 15 and 45 mm and preferably between 20 and 40 mm. The article 1 is also designed with fin-type projections 17, 18, which, in a known manner, can be provided with a suitable adhesive to secure the article 1 to the underwear during use. According to the embodiment, which is shown in Figures 1 and 2, article 1 comprises a further sheet 17, which consists favorably of one more absorbent sheet. For example, the first absorbent sheet, ie the absorption body 4, can be a "fast" material, which transports liquids, while the second absorbent sheet 17 can then be formed in order to have a good ability to store liquids. The subsequent sheet 17 can be a rigid material, that is to say it can be formed with both absorbent and rigidity properties, for the article 1. Alternatively, the subsequent sheet 17 can provide stiffness, but without having essentially absorbent properties, which it is the case if, for example, it consists of a foam material essentially, without absorbent properties. According to a further variant of the invention, article 1 can be formed so that the subsequent sheet 17 consists of an absorbent sheet, while the cross-stretched structure 4a, 4b is a rigid material. Similarly, with the above described, the structure mentioned to the last 4a, 4b then provides stiffness with absorbent properties or can provide rigidity without absorbent properties. The subsequent sheet 17 can be placed under the structure 4a, 4b laid crosswise, as can be seen in Figures 1 and 3. Alternatively, the cross-stretched structure 4a, 4b can be placed under the subsequent sheet 17. According to a further alternative, the subsequent sheet 17 can be placed between two core preforms 41, 4b, placed in a cross. Generally it can be said that the structure, indicated by the reference number 4 in Figures 1 to 3, constitutes a stiffening element, which is provided with two or more preforms, which, in turn, are placed in a substantially X-shaped configuration. This configuration element 4 is preferably supplemented by a further sheet 17, according to what was described above, in the case where the subsequent sheet 17 is a sheet that provides stiffness, the stiffness of the sheet 17 can be adapted appropriately to a configuration element. For example, the subsequent sheet 17 can be produced in such a way that it becomes more rigid than the configuration item 4, for example by the adhesive lamination of several sheets of identical or different materials or some other suitable production alternatives. The configuration of article 1 can also be clearly seen in Figure 3, which is a cross-sectional view along the line III-III in Figure 1. It will be seen from Figure 3 that the absorbent article 1, according to with the invention, it has a middle portion 8, which is relatively thick, since two preforms of the core 4a, 4b are laid crosswise and thus overlap each other in the middle portion 8. This means that the middle portion 8 has a capacity of of improved absorption, compared to the absorption capacity of each of the individual core preforms 4a, b. Figure 3 also shows the further sheet 17. A manufacturing process for the absorbent article 1, according to the invention, includes a step in which the absorption body 4 is disposed between the top sheet 2 and the bottom sheet 3 More specifically, the starting material for the absorption body 4 preferably consists of a wound absorbent material. The two long, narrow core preforms 4a, 4b are perforated from this material in the form of separate elements, which together form the absorption body 4. The core preforms 4a, 4b are then applied to the bottom sheet 3, after which the top sheet 2 is put in place and the entire article 2 is fixed in this configuration, using the core preforms 4a, 4b are applied , it is ensured that they are placed so that the configuration in X, mentioned above, is formed. In this way, a thicker core of absorbent material is obtained, where the preforms 4a, 4b of the core intersect each other. The position of this relatively thick section is also adapted to the area of article 1, where moisture is expected during use. It is also true that the size of this relatively thick section depends on the selection of the angle between the legs 13, 14 (see Figure 2) of each preform 4a, 4b of the core, but also on other parameters, such as, for example, the width and thickness of the strip that constitutes the starting material for the absorption body 4. It can be noted that such a suitable width for each core preform 4a, 4b is of the order of 25 mm. However, in the case of the invention applied in the form of a panty lining, this width may be smaller. An important advantage of the above-described manufacturing method is that a minimum waste of material is generated with respect to the absorbent article in question, and efficient formation of a relatively thick section in the middle portion 8 of article 1. In addition, the two legs 13, 14, mentioned above, are formed by the configuration in X, and they, in turn, contribute in a high degree to mobility. In an alternative approach in the manufacture of the absorption body 4, it is to use two strips of material separated from the absorbent material, which are arranged so that, when they are applied to the bottom sheet 3, they "tend in cross", is say in the configuration of X. The first preform 4a of the core, in this case, originates from the web of material, while the second core preform 4b originates from the second web of material. An alternative embodiment of the invention is shown in Figure 4, which shows a plan view of a configuration element, in the form of an absorbent core 4 '. According to this embodiment, two relatively narrow preforms 4a ', 4a "are used, which are laid crosswise, with two more preforms, 4b', 4b", which are relatively narrow. Otherwise, the absorbent core 4 ', according to Figure 4, may have an application corresponding to the modalities described above. The dimensions, such as the width and length of each preform 4a ', 4a ", 4b', 4b" can be selected depending on whether it is an absorbent material or a material that provides rigidity, which - constitute the structure in the form of a cross, and depending on whether the item in question is, for example, a sanitary napkin, a diaper, an incontinence protector or a panty lining. The material in the upper sheet 2 can be, for example, a perforated plastic film, a plastic net or a textile material, fiber batt, a non-woven material or a laminate of, for example, a perforated plastic film and a nonwoven sheet. The laminate can be made of any suitable material for the chosen purposes. The plastic material is usually a thermoplastic, such as polyethylene or polypropylene. The term "non-woven material" refers to a non-woven fiber fabric. Suitable non-woven materials may consist of natural fibers, such as cellulose or cotton, or synthetic fibers, such as polyethylene, polypropylene, polyester, polyurethane, nylon or regenerated cellulose. Of course, it is also possible to use nonwoven material produced from fiber blends. The upper sheet 2, permeable to the liquid, is intended to receive and transport the liquid in the absorption body 4. Furthermore, the upper sheet 2 should be both soft and comfortable against the wearer's body and capable of preventing the so-called rewetting, that is, when the absorbed body excretions force their way back to the users skin. For reasons of comfort and to prevent skin irritation, it is important that the surface of the portion of the absorbed article that is in contact with the wearer's skin is kept as dry as possible during use. In addition, a dry surface of the absorbent article feels colder and more comfortable to the wearer during use, and forms a purely visual point of view, and also when the handling of the absorbent article, is changed, is more attractive than a surface dirty, wet. However, to avoid irritation of the genital mucosa, those parts of the absorbent article in contact with the mucosa are preferably slightly moist. The article 1 can also be provided with a suitable additive or a lotion, in order to promote contact with the skin between the article and the user's body. It is not necessary, in all embodiments of the invention, for the top sheet 2 to constitute a separate sheet of material. The top sheet may, for example, constitute an integral part of an absorbent body. It is thus conceivable that if the upper sheet 2, ie the cover sheet, permeable to the liquid, is omitted, then the body The absorbent should comprise an absorbent foam sheet or other absorbent material, which is sufficiently adhesive to itself not to separate during use. In addition, it is possible to use an absorbent non-woven material, this material can be a component in the absorbent body and at the same time constitute a liquid-permeable topsheet. The bottom sheet 3, liquid tight, consists of a liquid-tight material. Plastic films, liquid tight, are suitable for this purpose. However, it is also possible to use a material which is originally liquid permeable, but which has been provided with a surface coating of plastic, resin or other liquid-tight material. In this way, the escape of the liquid from the underside of the absorbent article is prevented. The bottom sheet 3, liquid-tight, can consist of any material, which is favorable to the skin and satisfies the criterion of being liquid-tight. Examples of materials that are suitable as barrier sheets are plastic films, non-woven materials and different types of laminates. Plastic films that can be used are, for example, those consisting of polyethylene, polypropylene or polyester. Alternatively, the bottom sheet 3 may consist of a laminate made of a plastic sheet, liquid-tight, directed towards the absorbent body and of a non-woven sheet, directed towards the underclothes of the wearer. Such construction allows a leak-proof barrier sheet, with a textile feel. In the same way as with the upper sheet 2, it is not necessary for the bottom sheet 3 to constitute a separate sheet. Consequently, it is conceivable that the bottom sheet 3 constitutes an integral part of an absorbent material, for example, an absorbent foam material with a liquid-tight surface. The absorption body 4 may advantageously consist of essential pulp cellulose fibers. The pulp may be present in the form of spools, bundles or sheets that are crumbled dry or wet and converted into a state of hair on a pulp mat, with or without mixing with the so-called super-absorbers, which are polymers that have the ability to absorb several times their own weight of water or the excretions of the body. Examples of other 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 synthetic absorbent fibers or mixtures of natural and synthetic fibers. The absorption material can also include additional components, such as elements that distribute the liquid or binders, such as, for example, thermoplastic fibers, which have been heat treated to join together short fibers and particles in a coherent unit. It is also possible to use different types of absorbent foam materials in the absorption body 4. Also, this absorption body 4 can be provided with a means to inhibit odor. The invention is not limited to the above-described embodiment and can be modified within the scope of the appended patent claims. For example, the invention is not limited to the application in sanitary napkins and instead is also used in other types of absorbent articles, for example diapers, panty liners and incontinence guards. The invention can generally be used for all types of absorbent articles whose sizes fit substantially the groin area of a wearer. According to the aforementioned embodiment, the two strip forming each core preform 4a, 4b are substantially of the same width. Alternatively, however, they may have other dimensions and configurations, for example a narrower shape.

The chosen dimensions, according to the invention, for the different components involved can vary, depending on whether the invention is used as, for example, a sanitary napkin, diaper, incontinence protector or panty lining. Similarly, the article 1 can be provided with an elastic element (not shown), which is arranged between the two legs 13, 14, in the absorption body 4 and which is intended to stretch the legs of the article together and form a flange-type elevation between the first leg 13 and the second leg 14. In this manner, the adjustment can be increased and the risk of backward leaks throughout article 1 is reduced. More specifically, such an elastic element can be placed between the legs as a continuous filament or as a continuous band and is advantageously secured to the cover sheet 3, which is liquid-tight.

Claims (13)

1. CLAIMS | . Absorbent article, such as a sanitary napkin, diaper, incontinence protector or panty liner, which has a substantially elongated configuration, having a longitudinal direction and a transverse direction and having two side edges, a front edge and a trailing edge, a front portion, a rear portion and a middle portion, positioned between the front portion and the rear portion, this article also comprises a configuration element, characterized in that said configuration element is defined by an absorption body, which comprises at least two substantially elongated preforms, which are cross-shaped in at least one partially overlapped and substantially X-shaped configuration. Absorbent article, according to claim 1, characterized in that said article comprises a cover sheet, permeable to the liquid, and another sheet of cover, hermetic to the liquid. 3. Absorbing article, according to claims 1 or 2, characterized in that said configuration element consists of an element that provides rigidity. Absorbent article, according to any of the preceding claims, characterized in that the absorption body comprises at least two core preforms separated from the absorbent material. Absorbent article, according to any of the preceding claims, characterized in that the configuration element comprises a portion in which said preforms cross each other and corresponds to the middle portion of said article, where moisture is expected during use . Absorbent article, according to any of the preceding claims, characterized in that the configuration element is divided, in said rear portion, into a first leg and a second leg, with a gap between said legs, where an angle is defined between the first leg and the second leg. Absorbent article, according to claim 6, characterized in that said angle is between 10 and 120 degrees, preferably between 15 and 40 degrees. 8. Absorbing article, according to claims 6 or 7, characterized in that the length of each leg is between 20 and 350 mm, preferably between 50 and 140 mm, calculated from a point of intersection between said legs. 9. Method for manufacturing an absorbent article, such as a sanitary napkin, diaper, incontinence protector or pantyliner, said article having substantially an elongated configuration, having a longitudinal direction and a transverse direction and having two side edges, a front edge and a rear edge, a front portion, a rear portion and a middle portion, positioned between the front portion and the rear portion, and also has a configuration element, characterized in that this method comprises: producing at least two substantially elongated preforms, which they constitute said configuration element, this configuration element is defined by an absorption body; and placing said preforms crosswise in at least one partially overlapped configuration, substantially X-shaped. 10. Method, according to claim 9, characterized in that it comprises placing a portion in which the preforms cross each other, in a middle portion of said article, where moisture is expected during use. Method, according to claims 9 or 10, characterized in that the preforms are produced by perforating or cutting them from a strip or a roll of the absorbent material. 12. Method according to claim 9 or 10, wherein the preforms are produced by cutting them from separate strips or rolls of absorbent material. Method, according to any of claims 9 to 12, characterized in that it comprises joining together a structure comprising a liquid permeable cover sheet and a liquid-tight cover sheet, said preforms are placed between said cover sheets.