Stretchable absorbent article
Abstract
AN ABSORBENT STRETCHABLE ARTICLE, SUCH AS A DIAPER, A SANITARY PRODUCT OR ANOTHER ABSORBENT ELEMENT, INCLUDES A LAYER (3) PERMEABLE TO LIQUIDS, AND A (2) ELASTIC WATERPROOF, CLAMPABLE TO THE PERMEABLE LAYER LIQUIDS IN DISCRETE ZONES, WHICH ARE FORMED NON-SECURITY ZONES BETWEEN THE SECURITY ZONES (4). THE PERMEABLE LAYER TO LIQUIDS FORMS SPLINES OR WRINKLES IN THE RESPECTIVE NON-SECURITY ZONES TO RESPECTIVELY DEFINE CHANNELS (5) BETWEEN THE PERMEABLE LAYER TO LIQUIDS AND THE ELASTIC LAYER WATERPROOF TO LIQUIDS. THE ABSORBENT MATERIAL (6) IS LOCATED IN SELECTED AREAS OF THE CHANNELS.

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Projected expiry passed 11 August 2013, 13.1 years ago.
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26 claims: 6 independent, 20 dependent
- 1ES 2 149 185 T3 REIVINDICACIONES 1. Un artáculo absorbente estirable para ajustarse alrededor de la cintura de un usuario, cuyo artáculo comprende un cuerpo principal (10) que incluye una laámina compuesta elaástica (1) y un cuerpo absorbente asegurado a la misma, comprendiendo dicha láamina compuesta elaástica (1) una láamina eláastica (2) y un gáenero no tejido (3) asegurado a una de las superficies de dicha laámina eláastica (2), estando asegurada dicha capa de gáenero no tejido (3) a dicha láamina elaástica (2) de forma continua en una primera direcciáon y de forma intermitente en una segunda direccioán perpendicular a dicha primera direcciáon, para definir entre ambas una pluralidad de canales paralelos (5) que se extienden en dicha primera direccioán, caracterizado porque dicho artáculo absorbente estirable incluye capas dobles de dicha láamina compuesta eláastica (1) en la regioán de al menos una de las siguientes porciones:una porciáon de cintura frontal (11), una porcioán de cintura posterior (12), una porciáon de cruz y porciones que rodean las aberturas para las piernas de dicho cuerpo principal (10), comprendiendo cada una de dichas laáminas compuestas elaásticas (1) una de dichas laáminas elaásticas (2) y uno de dichos gáeneros no tejidos (3).
- 2Una artáculo absorbente estirable seguán la reivindicaciáon 1, caracterizado porque dicho cuerpo absorbente estáa dispuesto dentro de dicho cuerpo principal (10).
- 3Un artáculo absorbente estirable seguán la reivindicacioán 1, caracterizado porque dicha laámina eláastica (2) es una laámina estratificada fina seleccionada entre peláculas que consisten en un material elegido entre caucho natural o sintáetico, poliuretano, polámero en bloque de estireno-butadieno, y EVA, LLDPE de densidad ultrabaja, elastáomero de etileno-propileno, elastoámero de etileno-acrilato de metilo y una mezcla del mismo con un copolámero en bloque de estireno-etileno-butadieno-estireno;una pelácula co-extruida de elastáomeros de poliuretano y elastoámeros de poliolefinas;y un gáenero no tejido de poliuretano soplado en estado fundido.
- 4Un artáculo absorbente estirable seguán la reivindicaciáon 1, caracterizado porque dicho gáenero no tejido (3) comprende fibras sintáeticas hidroáfilas seleccionadas del grupo consistente en rayoán y algodáon.
- 5Un artáculo absorbente estirable seguán la reivindicaciáon 1, caracterizado porque dicho gáenero no tejido (3) comprende fibras sintáeticas hidroáfobas seleccionadas del grupo consistente en polipropileno, poliáester y nylon.
- 6Un artáculo absorbente estirable seguán la reivindicaciáon 1, caracterizado porque dicho gáenero no tejido (3) que comprende fibras sintáeticas hidráofobas es tratado con surfactantes.
- 7Un artáculo absorbente estirable seguán la reivindicaciáon 3, caracterizado porque dicho cuerpo absorbente estáa dispuesto para extenderse longitudinalmente por el interior de una porciáon de cruz del artáculo absorbente y queda asegurado a una superficie interior de una porciáon de cruz en una porciáon de sujeciáon alargada similar a una banda (24) de la misma y situada de una modo centralmente transversal respecto a la misma.
- 8Un artáculo absorbente estirable seguán la reivindicacioán 3, caracterizado porque dicho cuerpo absorbente queda dispuesto para extenderse longitudinalmente por el interior de una porcioán de cruz del artáculo absorbente y en adicioán se extiende hacia el exterior de sus respectivos lados transversales, quedando asegurado dicho cuerpo absorbente en una superficie interior de la porcioán de cruz en los extremos libres de la laámina posterior.
- 9Un artáculo absorbente que comprende una regiáon estirable que incluye una capa permeable a los láquidos (4), una capa elaástica (6) asegurada de forma estirable a dicha capa permeable a los láquidos, para formar regiones carentes de sujecioán entre zonas adyacentes de dichas regiones de sujecioán, formando dicha capa permeable a los láquidos corrugaciones en las respectivas regiones de no sujecioán, para definir respectivos canales (114) entre dicha capa permeable a los láquidos y dicha capa eláastica, caracterizado porque dicha capa elaástica es una capa impermeable a los láquidos (111), porque el artáculo absorbente comprende regiones estirables que incluyen dicha capa permeable y dicha capa eláastica impermeable, porque dicha capa permeable a los láquidos y dicha capa impermeable a los láquidos estaán aseguradas entre si en regiones separadas y porque el material absorbente (115) queda dispuesto en canales seleccionados de tales canales.
- 10Un artáculo absorbente seguán la reivindicacioán 9, caracterizado porque dicha capa permeable alosláquidos es una láamina superior (3), dicha capa eláastica impermeable a los láquidos es una laámina posterior (2) que tiene una zona elaástica y dichas regiones separadas de sujeciáon consisten en una pluralidad de láneas de sujeciáon (4) paralelas y espaciadas mediante las cuales dicha zona elaástica de la laámina ES 2 149 185 T3 posterior (2) queda asegurada a dicha laímina superior (3), quedando dispuesto dicho material absorbente en dichos canales en una posicioín seleccionada de dicho artículo absorbente.
- 11Un artículo absorbente que comprende una laímina superior permeable a los líquidos (3);una capa elíastica asegurada de forma estirable a dicha laímina superior permeable a los líquidos mediante una pluralidad de líneas de sujeciíon (4) paralelas y espaciadas, para formar regiones de no sujeciíon, formando dicha capa permeable a los líquidos respectivamente corrugaciones en dichas regiones de no sujecioín para definir una pluralidad de canales (5) entre dicha laíminas superior permeable a los líquidos y dicha capa elíastica, caracterizado porque la capa elaística constituye la laímina posterior impermeable a los líquidos (2) del artículo absorbente, porque la laímina posterior impermeable tiene una zona elaística asegurada a dicha laímina superior y porque el material absorbente queda dispuesto en dichos canales en una posicioín seleccionada de dicho artículo absorbente.
- 12Un artículo absorbente seguín la reivindicaciíon 11, caracterizado porque dicha posiciíon seleccionada es una regioín de cruz del artículo absorbente.
- 13Un artículo absorbente seguín la reivindicacioín 12, caracterizado porque dicha posicioín seleccionada es una regioín central lateral del artículo absorbente.
- 14Un artículo absorbente seguín la reivindicacioín 13, caracterizado porque dichas líneas de sujeciíon (4) paralelas estaín lateralmente espaciadas entre si para definir dichos canales (5) que se extienden longitudinalmente entre regiones anterior y posterior de dicho artículo absorbente.
- 15Un artículo absorbente seguín la reivindicacioín 14, caracterizado porque dicho material absorbente (6) comprende una pluralidad de segmentos absorbente dispuestos longitudinalmente en dicho canal.
- 16Un elemento absorbente estirable que comprende una regioín estirable que incluye una capa permeable a los líquidos (212), una capa elíastica (211) asegurada de forma estirable a dicha capa permeable a los líquidos, para formar regiones de no sujeciíon entre las regiones adyacentes de dichas regiones de sujeciíon, formando dicha capa permeable a los líquidos corrugaciones en las respectivas regiones de no sujeciíon para definir así los respectivos canales (214) entre dicha capa permeable a los líquidos y dicha capa elíastica, caracterizado porque dicha capa elaística es una capa impermeable a los líquidos, porque el elemento absorbente comprende regiones estirables que incluye a dicha capa permeable y dicha capa elíastica impermeable, porque dicha capa permeable a los líquidos y dicha capa impermeable a los líquidos estían aseguradas entre sí en regiones separadas y porque el material absorbente (232) estaí dispuesto en canales seleccionados de dichos canales.
- 17Un elemento absorbente estirable seguín la reivindicaciíon 16, caracterizado porque dicho material absorbente comprende material superabsorbente.
- 18Un elemento absorbente estirable seguín la reivindicacioín 17, caracterizado porque dicha capa permeable a los líquidos comprende un gíenero no tejido.
- 19Un elemento absorbente estirable seguín la reivindicacioín 16, caracterizado porque dichas regiones de sujecioín separadas consisten en una pluralidad de líneas de sujeciíon paralelas y espaciadas.
- 20Un elemento absorbente estirable seguín la reivindicacioín 19, caracterizado porque dicho material absorbente tiene una configuracioín preformada que presenta un aírea en secciíon transversal lateral sustancialmente uniforme.
- 21Un elemento absorbente estirable seguín la reivindicaciíon 20, caracterizado porque dicho material absorbente preformado comprende fibras hidroífilas y polímeros superabsorbentes.
- 22Un elemento absorbente estirable seguín la reivindicaciíon 21, caracterizado porque dicho material absorbente preformado comprende un haz de fibras superabsorbentes.
- 23Un elemento absorbente estirable seguín la reivindicacioín 21, caracterizado porque dicha aírea en secciíon transversal lateral del material absorbente preformado es igual o menor que la mitad del íarea en secciíon transversal lateral del canal que incluye a dicho material absorbente.
- 24Un elemento absorbente estirable seguín la reivindicaciíon 21, caracterizado porque dicho ele11 ES 2 149 185 T3 mento absorbente tiene una pluralidad de porciones laterales y porque dichos canales, en una de dichas porciones laterales, tienen un aárea en secciáon transversal lateral mayor que la de los canales de una porcioán lateral adyacente.
- 25Un elemento absorbente estirable seguán la reivindicaciáon 24, caracterizado porque dichos canales, en una porcioán lateral central de la estructura absorbente, tienen un aárea en secciáon transversal lateral mayor que la de los canales de porciones laterales en lados opuestos de dicha porcioán lateral central.
- 26Un elemento absorbente estirable seguán la reivindicaciáon 25, caracterizado porque dicho material absorbente incluido en los canales en una de dichas porciones laterales tiene un áarea en secciáon transversal lateral mayor que la del material absorbente situado en los canales de la porciáon lateral adyacente. NOTA INFORMATIVA:Conforme a la reserva del art. 167.2 del Convenio de Patentes Europeas (CPE) y a la Disposición Transitoria del RD 2424/1986, de 10 de octubre, relativo a la aplicación del Convenio de Patente Europea, las patentes europeas que designen a España y solicitadas antes del 7-10-1992, no producirán ningún efecto en España en la medida en que confieran proteccián a productos químicos y farmacáuticos como tales. Esta informacioán no prejuzga que la patente estáeonoincluáda en la mencionada reserva.
Independent claims26
98 paragraphs in 5 sections, as filed
IS 2 149 185 T3
DESCRIPTION
Stretchable absorbent article.
Technical field
The present invention relates generally to absorbent articles such as diapers, sanitary products and absorbent elements suitable for use in such diapers, and more particularly relates to an absorbent article that is elastically stretchable.
Background of the invention
Disposable absorbent articles, such as diapers, sanitary products, incontinent pads, and the like, have gained wide acceptance by users. Such absorbent articles generally include a liquid permeable sheet, a liquid impermeable sheet to prevent exudates from escaping from the body, and an absorbent element interposed therebetween to absorb said body exudates.
Conventional liquid impervious sheets provide satisfactory liquid impermeability. However, such lamines are not flexible enough to closely conform to the shape of the wearer's body and consequently achieve poor protection against leakage.
Various types of materials have been proposed for use in absorbent elements and they have been able to be used in actual practice. In addition, with the progress of development work on superabsorbent materials that comprise polymeric material capable of absorbing more than ten times its weight of liquids, the absorbent elements that incorporate said superabsorbent material have been widely used.
Absorbent elements such as those already proposed or used in actual practice have a paneled configuration to present a flat absorbent surface for contact with liquids over its entire surface, in an attempt to obtain absorbency of the target liquid. Although such absorbent elements provide satisfactory liquid absorbency, they are not flexible enough to conform to the user's body during use. In particular, absorbent elements incorporating superabsorbent material exhibit a significant increase in stiffness when the superabsorbent material absorbs liquids. This increase in the rigidity of the absorbent elements causes a poor adaptation of the same to the user's body, which leads to liquid leakage from the sides of such elements.
Among the state of the art of mine, a stretchable absorbent article is also known from EP321980 to fit around the waist of a wearer. This article consists of a main body comprising an elastic composite lamina and an absorbent body secured thereto. The elastic composite sheet described in EP321980 comprises an elastic sheet and a non-woven fabric secured to a surface of said elastic sheet. More specifically, the non-woven fabric was secured to one of the surfaces of the elastic sheet continuously in a first direction and intermittently in a second direction perpendicular to said first direction, in order to define a plurality of channels between them. parallels that extend in said first direction.
The present invention provides a highly functional absorbent article that, at the same time, is elastically stretchable and contractable to better conform to the wearer's body during use.
Summary of the invention
The present invention provides a stretchable absorbent article as claimed in claim 1 and an absorbent article as claimed in claims 9 and 11.
The present invention further provides a stretchable absorbent element as claimed in claim 16.
The present invention, according to claim 1, provides a stretchable absorbent article comprising double layers of an elastic composite lamina, each of said elliptical composite laminates comprising one of said elliptical laminates and one of said nonwoven fabrics. On the contrary, EP-A556749 (which is a document according to Art. 54 (3) EPC) refers to
ES 2 149 185 T3 a stretchable article that provides a composite sheet comprising only an elastic sheet and nonwoven fabrics that can be attached to both sides of the elastic sheet.
On the other hand, EP-A-556749 refers to a laminar support material consisting of an impermeable layer of non-woven fabric, while the present stretchable absorbent article comprises an elastic composite sheet that includes a non-woven fabric, which is a permeable layer.
Other features and advantages of the present invention will become readily apparent from the following detailed description, accompanying drawings, and appended claims.
With reference to the characteristics shown in the following Figures 1 to 4, 10, 13-15, 18, 20 and 21, insofar as they show a composite sheet comprising only an elastic sheet and a non-woven fabric. , said characteristics are not covered by claim 1. However, said Figures are attached to achieve a better description of the claimed products.
Brief description of the drawings
Figure 1 is a perspective view illustrating a first embodiment of liquid impervious protective article.
Figure 2 is a cross-sectional view taken along line AA of Figure 1.
Figure 3 is a fragmentary perspective view of a composite sheet of the protective article of Figure 1.
Figure 4 is a perspective view of a second embodiment of a liquid impervious protective article according to the present invention.
Figure 5 is a cross-sectional view taken along line BB of Figure 4.
Figure 6 is a front view of a third embodiment of a liquid impervious protective article according to the present invention.
Figure 7 is a cross-sectional view taken along line CC of Figure 6.
Figure 8 is a front view of a fourth embodiment of a liquid impervious protective article of the present invention.
Figure 9 is a cross-sectional view taken along line DD of Figure 8.
Figure 10 is a cross-sectional view of a fifth embodiment of a liquid impervious protective article.
Figure 11 is a cross-sectional view illustrating an absorbent body and attachment means thereof in the liquid impervious protective article of Figure 10.
Figure 12 is a cross-sectional view illustrating another embodiment of an absorbent body and attachment means thereof in the liquid impervious protective article of Figure 10.
Figure 13 is a cross-sectional view illustrating a sixth embodiment of a liquid impervious protective article.
Figure 14 is an enlarged, fragmentary cross-sectional view of Figure 13.
Figure 15 is a perspective view illustrating a seventh embodiment of a liquid impervious protective article.
Figure 16 is a cross-sectional view illustrating a preferred construction of a holding portion of a liquid impervious protective article in accordance with the present invention.
Figure 17 is an explanatory view illustrating various fastening designs applied to a fastening portion of the liquid impervious protective article in accordance with the present invention.
IS 2 149 185 T3
Figure 18 is a fragmentary perspective view illustrating one embodiment of the absorbent element.
Figure 19 is an enlarged and fragmented cross-sectional view of the absorbent element of Figure 18.
Figure 20 is a cross-sectional view illustrating another embodiment of the absorbent element.
Figure 21 is a cross-sectional view illustrating still another embodiment of the absorbent element.
Figure 22 is a cross-sectional view illustrating one embodiment of the mold used to produce the absorbent element in accordance with the present invention.
Figure 23 is a cross-sectional view illustrating another embodiment of the mold used in the production of the absorbent element in accordance with the present invention.
Detailed description
Although the present invention is capable of being put into practice in various ways, in the attached drawings and in the following description detailed specific modalities of the same were offered, it being understood that the present description must be considered as exemplary of the invention and that the latter is not limited in any way to the specific illustrated modalities.
Referring now to the drawings, Figure 1 is a perspective view illustrating an absorbent article, such as a honeycomb liquid-impermeable protective article, incorporating the principles of the present invention. Figure 2 is a cross-sectional view taken along the line A-AdelaFigure1. In Figures 1 and 2, the liquid-impervious protective article was provided with a main body 10 comprising a first portion 11 having a configuration covering the front surface of the waist of the body and a second portion 12 covering a surface. back of the body waist. These first and second portions 11, 12 are formed by cutting a composite lamina 1, as described below, to form a generally rectangular piece, folding the piece twice along a longitudinal central portion and joining the folded portions together in junction portions 13 located at the respective lateral ends of the folded portions.
The composite lamine 1 constituting the first and second portions 11, 12 is constructed by securing a non-woven fabric 3 on at least one surface of a liquid-impervious elastic loamine 2, as shown in Figure 3. The non-woven fabric is it secures the elastic sheet 2 continuously in a first direction and intermittently in a second direction transverse to the first direction. The clamping of these two elements was carried out along parallel clamping lines 4 spaced apart, such as at regular intervals. The width of the non-woven fabric 3 is made to be greater than the width of the elastic sheet 2 between adjacent fastening lines 4, so that between the elastic lamina 2 and the non-woven fabric 3 a plurality of parallel channels 5 are formed extending in the first direction. This composite lamina 1 is cut or contoured according to the desired shapes and dimensions of the first and second portions 11, 12, which are then joined together in order to form the non-woven geon 3 facing inwards.
In a liquid-impermeable protective article 10 of said construction, the inwardly placed non-woven fabric 3 comes into contact with the wearer's body when the article 10 is applied to the latter and a plurality of elongated channels 5 are provided between said non-woven gene 3 and elastic loamine 2. Therefore, the breathability and flexion capacity of the non-woven fabric 3 per se and the channels 5 provide a comfortable feeling during use, offering a soft touch to the skin. The outwardly positioned elastic lamina 2 is impermeable to liquids, so that the latter cannot efficiently escape through the article.
Although the main body 10 comprising the first and second portions 11, 12 is illustrated in the embodiment of Figure 1, as being single-layered throughout its entire region, it can be double-layered (that is, double) placing a tape-like reinforcing element 14 of a suitable width and cut from the composite lamina 1 on the respective upper end portions of the first and second portions 11, 12, as illustrated in Figures 4 and 5. This construction increases the resistance as well as the elastic contraction capacity in such portions, so that any
ES 2 149 185 T3 breakage that may be caused by careless handling of the article during use. Its stability around the body's waist during use will also be improved. The attachment of the main body 10 and the reinforcing element 14 can be easily accomplished through the use of heat compression, hot melt type adhesives and other similar means. Said reinforcement can alternatively be achieved by making the main body 10 longer than the desired dimension and folding its upper end portion on itself.
Alternatively, the main body 10 may be double-layered in its cross region by providing a reinforcing element 15 that has a shape corresponding to that of said region as illustrated in Figures 6 and 7. Another modality will follow. , the reinforcing elements 14a, 14b can be attached respectively to two portions surrounding the leg openings, as illustrated in Figures 8 and 9. In either embodiment, the portions of the leg openings, to which a relatively large stretching force is applied when the wearer's article is placed on or removed, are double-layered so as to effectively avoid breaking into such portions. The cross section or leg opening reinforcement portion can be combined with a waist reinforcement portion as illustrated in Figure 4.
Figure 10 shows another embodiment of a liquid impervious protective article according to the present invention. The liquid-impermeable protective article 20 of this embodiment has the main body 10 of the construction, wherein the first portion 11 and the second portion 12 are joined together in the joint portions 13, formed with the folded portion 14 in its position. upper extreme portion, similar to the construction shown in Figure 4. The article 20 is also provided with an absorbent body 21 located in its cross region. The absorbent body 21 may be of the type used for conventional diapers or sanitary napkins and is fixedly secured in a predetermined position by means such as glues, hot melt adhesives and the like.
Said absorbent body as described above is stiff per se and, therefore, lacks elasticity and flexibility as exhibited by the composite sheet 1, with the result that the elasticity in a portion of the main body 10 is impaired when said absorbent body rigid is attached to the main body portion of the present item. To avoid such drawbacks, the union illustrated in Figures 11 and 12 can preferably be used.
The absorbent body 21, as illustrated in Figure 11, comprises an absorbent element 22 and a liquid-permeable coating 23 to envelop the absorbent element 22. The absorbent body 21, in its central transverse position, is secured to the nonwoven side of the composite sheet 1 only along an elongated fastening portion 24 similar to a band that extends over the entire length of the absorbent body, and formed by means such as glues, hot melt adhesives, and the like. Such a construction allows the composite sheet to be less affected by the attachment of the absorbent body 21 thereto and allows the absorbent body 21 to be free from the stretching and contraction action of the composite sheet. Thus, the construction allows any deformation of the absorbent body along the shape of the wearer's body and adapts to the dimensional change of the absorbent element after absorption of the liquid. Furthermore, the absorbent body does not move or displace from the predetermined position. Consequently, leaks are completely avoided and a very comfortable feeling is achieved. Alternatively, absorbent body 21 may comprise a liquid-permeable top sheet 25 to cover the top and side surfaces of absorbent element 22 and a back sheet 26 to cover the bottom surface of absorbent element 22, as illustrated in Figure 12. Beneath the absorbent element 22, portions of the topsheet 25 and backsheet 26 extending from each side edge of the absorbent element 22 are folded into a U-shaped configuration. The portions are secured to the composite sheet 1 in the band-type fastening portions 27 which are located at the forward ends of the extension portions and which are formed by means such as glues, hot melt adhesives and the like. In this construction, the absorbent element 22 assumes a "floating" position above the composite sheet, such that the movement of the absorbent element 22 is substantially independent of the movement of the composite sheet. This provides approximately the same or greater degree of leak protection and comfort than the construction in Figure 10.
Figure 13 shows another embodiment of the liquid impervious protective article 30 intended to further enhance the effects of the present invention. In this embodiment, the composite sheet 1 includes absorbent material 6 located within the channels defined between the elastic sheet 2 and the nonwoven fabric 3, as illustrated in Figure 14. The absorbent material 6 can be located throughout the region of laamina compound 1. Alternatively, the absorbent material 6 can be located only in a region
ES 2 149 185 T3 cross section of the composite sheet 1 with which contact with the body exudate is possible, as illustrated in Figure 13. Said absorbent material 6 absorbs the body exudates that have passed through the non-woven fabric 3 and penetrating the channels 5. This eliminates the need to provide a separate absorbent body.
A suitable absorbent material 6 to be placed within the channels 5 includes a hydrophilic material such as pulp or cotton, or a synthetic fibrous material, such as polypropylene, polyesters and the like, which is hydrophilicized by hydrophilic treatment. Preferably, said absorbent material uses superabsorbent material generally known as SAP (Super Absorbent Polymer) capable of absorbing several times its own weight of water or aqueous liquids.
In the case that the superabsorbent material is used in the form of particles, it is necessary that the non-woven fabric that constitutes the walls of the channels 5 is of high quality in terms of the filtration function to prevent the particles from passing through the same. Preferably, the superabsorbent material can be incorporated into the absorbent material in various ways. An example would be strips of suitable widths cut from a composite sheet material comprising particles of superabsorbent material and pulp or a fibrous web. Another example is a bundle of superabsorbent fibrous material such as RUNSEAL produced and sold by Toyobo Corp. under said trade name. Strips cut from a fibrous web with superabsorbent material deposited on its surface can also be used. Said material can be produced by polymerization and crosslinking of a monomer solution placed on the surface of the fibrous web.
The volume of the absorbent material increases as it absorbs liquids. In particular, the superabsorbent material exhibits a drastic change in volume before and after absorption of liquids. Therefore, when a cross-sectional area of the absorbent material is chosen to correspond substantially to that of the channel space, the channel should be enlarged to such an extent that the superabsorbent material swells as it absorbs liquids. Said enlargement will be easily compensated mainly by the stretching action of the elastic sheet. However, it is preferable that said cross-sectional area of the absorbent material is chosen within a range such that the cross-sectional area after swelling is smaller than that of the channel space when swelling of the absorbent material is drastic, such as with superabsorbent material, or when such volume change is undesirable. This range of selection creates a free space within the channel, so that the superabsorbent material can swell freely without limitation and fully utilize its absorbent capacity.
In the respective embodiments illustrated in Figures 1-14, the main body is constructed by forming the leg openings in a single generally rectangular composite sheet 1, folding sheet 1 twice along its longitudinal central portion and joining or securing the portions folded together at their respective opposite lateral ends. In an alternative embodiment as illustrated in Figure 15, the main body 10 is constructed by securing the first and second portions
11,12 cut separately from the composite sheet along the lateral end fastening portions 13 and a lower end fastening portion 15.
In the respective embodiments described above, the fastening portions for securing the first and second portions to each other can be formed by securing opposite nonwoven fabrics 3 to each other and facing inwardly by any suitable fastening means, such as heat sealing, hot melt type adhesives and the like. Preferably, the main body 10, in portions corresponding to the clamping portions, is folded outward to define folded portions 1a having a suitable length, preferably equal to the length of the clamping portion. The folded portions 1a are secured to each other along the fastening lines 16. In this construction, the U-shaped folded nonwovens 3 are located at the side edges of the respective fastening portions, so that said portions provide soft and uniform surfaces such as against an outer garment, thereby providing an enhanced feel. comfort during the use of the article, in contrast to the previous construction where cut edges of the elastic sheet 2 are projected towards said portions.
On the other hand, the fastening of the composite sheet 1 to itself in the fastening portions 13, 15 can be carried out along two fastening lines parallel to each other, as illustrated in Figure 16. Alternatively, the fastening is It can be effected in patterns (a) - (n) illustrated in Figure 17. In particular, intermittent patterns, such as (c) - (n) in Figure 17, provide less resistance than continuous patterns. Such intermittent designs may preferably be employed to
ES 2 149 185 T3 articles such as honeycomb liners which can be removed from the user by breaking the main body 10.
It has been found that the very flexible nature of the composite sheet allows it to be folded into a compact shape, so as to facilitate its transport and use.
Figure 18 is a perspective view illustrating an absorbent element incorporating the principles of the present invention.
Figure 19 is an enlarged and fragmented cross-sectional view of Figure 18. In Figures 18 and 19, an absorbent member 110 in the form of a lamine comprises an eliasic lamina 111 and a nonwoven fabric 112 which are continuously secured to each other in a first direction of the nonwoven fabric 112, such as in the direction of the machine, and intermittently in a second direction perpendicular to the first direction, that is, in a direction transverse to the machine, along the clamping lines 113. A width of the nonwoven fabric 112 is chosen between the adjacent fastening lines 113 to be greater than the width of the elastic sheet 111, so that between the elastic sheet 111 and the nonwoven fabric 112 a plurality of channels 114 are formed. that extend in the direction of the machine.
An absorbent material 115, such as of an elongated band-type configuration and cut from superabsorbent lamina, was positioned in the channels 114 so as to extend the entire length of the respective channel 114. The cross-sectional area of the material Absorbent 115 is chosen to be about 1/2 or less, eg, 1/5 of the area of channel 114.
The absorbent material 110 thus constructed is placed in the actual practice so that the nonwoven fabric 112 comes into contact with the liquids. For example, when the absorbent element 110 is incorporated into a diaper or sanitary napkin, the nonwoven fabric 112 serves as a topsheet facing the wearer's body and the elastic sheet 111 serves as a liquid-impermeable backsheet to prevent leakage. liquids. Liquid is absorbed by absorbent materials 115 located in channels 114.
Figure 20 illustrates another embodiment of the absorbent element according to the present invention. The absorbent element 220 in this embodiment has two different channels 221, 222 of different areas in cross section. The cross-sectional area of each of the first channels 221, which are located in a laterally central portion A of the absorbent sheet 220, is greater than that of the second channels 222 that are located in lateral portions B on opposite sides of the laterally central portion A. The cross-sectional area of the first absorbent materials 223 located in the first channels 221 is proportionally greater than that of the second absorbent materials 224 located in the second channels 222.
The absorbent element 220 of the construction illustrated in Figure 20 therefore has a greater liquid absorption capacity in the central portion A than in the lateral portions B. This characteristic is especially suitable for use in articles that have a narrow central region. in which liquids are discharged in a concentrated form.
The ribbed structure of the absorbent elements illustrated in Figure 18-21 is, in its dry state (prior to absorption of liquid), effective in enhancing the diffusion and flow of liquids and air in a longitudinal direction and, in its humid state (after absorption of liquid) is effective in enhancing the diffusion of the liquid to rapidly diffuse the liquid received therein in the longitudinal direction, with the result that the liquids are distributed within all the regions of the absorbent elements located in the channels in a short period of time, thus achieving an effective absorption capacity of the absorbent lamina.
The means for securing the elastic sheet 211 and the nonwoven fabric 212 to form the channels 214 are not limited to any special one. For example, the preformed corrugated nonwoven fabric 212 can be placed on the flat elastic sheet 211 to contact each other. The contact portions are then secured to each other by any suitable means such as adhesives, sonic sealing, heat compression, and the like. My preferable method is to perform the fastening by placing the non-woven fabric in contact with the elastic film while it is in a viscous state during the production process.
Other means of forming the channels may utilize the difference between the elongation rates of the nonwoven fabric in the machine direction and in the cross-machine direction.
IS 2 149 185 T3
Specifically, the non-woven fabric is located on at least one of the surfaces of the elastic sheet. They are then secured to each other continuously in the machine direction and intermittently in the cross-machine direction, to form the composite sheet. The composite sheet is then stretched in the cross-machine direction by a ratio greater than the elastic limit of the nonwoven fabric, so that a permanent elongation is created in the nonwoven fabric. When this action disappears, channels are formed in the composite sheet since the permanently elongated nonwoven fabric has a greater width than the width of the elastic sheet between adjacent tie lines. In said method of forming the channels, nonwoven fabrics are suitably used that have an elongation speed in the transverse direction to the machine that is greater than in the machine direction, as illustrated by numbers 3 and 4 in the Table I.
The placement of the absorbent material in the ribbed structures can be accomplished by placing the absorbent material between the elastic sheeting and the nonwoven fabric prior to securing the latter together to form the channels. However, in order to place the absorbent material in the precise positions in actual industrial practice, a method such as that illustrated in Figures 22 and 23 may preferably be employed. The nonwoven fabric 312 is disposed within a mold 351 or 352 having rows of grooves, mechanically or by vacuum aspiration, such that a plurality of spaced upper surface portions and channels are provided between adjacent upper surface portions. A plurality of individual absorbent materials 315 are then placed in the respective channels of the nonwoven sheet 312. Finally, the elastic sheet 311 is secured over the spaced upper surface portions of the nonwoven fabric 312, to include the individual absorbent materials 315 within the respective channels. The mold 351 illustrated in Figure 22 has a plurality of cross-sectional equal-area grooves where individual cross-sectional equal-area absorbent materials are located. On the other hand, the mold 352 illustrated in Figure 23 exhibits central grooves having a greater cross-sectional area than that of the lateral grooves on opposite sides of the central grooves. Similarly, the individual absorbent materials 315 located in the central grooves have a greater cross-sectional area than those located in the lateral grooves.
Furthermore, the composite absorbent element according to the present invention has a construction such that absorbent materials with high liquid absorption capacity are located in the channels defined between the elastic sheet and the non-woven fabric. The liquids pass through the nonwoven fabric into the channels where they are absorbed by the absorbent materials.
When it is desired that a selected portion of the absorbent surface of the absorbent element of the present invention absorb a greater volume of liquids than the remaining portions of the absorbent surface, the amount of absorbent materials located in the channels located in the selected portion can be increased. . Said density distribution of the absorbent elements can preferably be effected by varying the cross-sectional areas of the channels to include absorbent materials in selected portions of the absorbent surface in accordance with a desired distribution. The absorbent element of such a construction is particularly suitable for use in baby diapers and sanitary napkins having a central target area into which liquids are discharged significantly.
The elastic sheet to be used in the absorbent element of the present invention includes a thin laminated sheet such as films consisting of a material selected from natural or synthetic rubbers, polyurethane, styrene-butadiene block polymers, EVA, ultra-low-density LLDPE, elastomer. ethylene-propylene, ethylene-methyl acrylate elastomer and mixtures thereof with a styrene-ethylene-butadiene-styrene block copolymer; co-extruded films of polyurethane elastamers and polyolefin elastamers; and melt blown polyurethane nonwovens.
The nonwoven fabric to be used in the absorbent element of the present invention is selected considering first its function as an absorbent and secondly its ability to form channels. In order for the nonwoven fabric to function as an absorbent, it needs to be permeable to liquids without adverse results against the skin during use. From the point of view of the ability to form channels, their adhesive characteristics with a film and their ability to maintain a fluted configuration should be taken into account.
Based on the above considerations, the following nonwovens may be conveniently employed: lower basis weight nonwovens (preferably less than 50 g / m2)<sup>2</sup>) manufactured by methods such as dry deposition, spunbond, spunbond, and simi8
ES 2 149 185 T3 lares, from relatively low denier fibers (preferably less than 5d) comprising hydrophobic synthetic fibers such as polypropylene, polyesters, nylon and the like, hydrophilic fibers such as rayon, cottonwood and the like or any combination from the same.
Nonwoven fabric predominantly comprising hydrophobic fibers can preferably be treated with surfactants that are safe for the skin to render the fabrics highly permeable to liquids. When the nonwoven fabric predominantly comprises hydrophilic fibers such as rayon fibers, it is desirable that said hydrophilic fibers comprise antibacterial fibers that are safe for the skin in order to avoid adverse effects on the skin that may be caused by a high content of water in a surface layer of the hydrophilic fibers. Commercially available fibers such as CHITOCELL (trade mark) or CHITOPOLY (trade mark) produced by Fuji Spinning Corp. can be used effectively.
Table I provides a list of typical nonwovens for use in the absorbent element of the present invention. In particular, spunbond, nonwoven fibers, such as those indicated with number 3 in Table I, are particularly suitable for the intended purpose since they exhibit a high proportion of elongation in the channel width direction and They also have high resistance.
Examples of nonwoven fabrics suitable for the present invention are illustrated in Table I.
TABLE I
<td>Not</td><td colspan="2">Gender type no</td><td>tissue</td><td colspan="2">Raw fiber</td><td>Band</td>
<td> 1</td><td colspan="3">Spunbond</td><td>PPx2.2dx</td><td></td><td>Random</td>
<td></td><td></td><td></td><td></td><td colspan="3">Continuous filament</td>
<td> 2</td><td colspan="3">Thermally bonded</td><td colspan="2">PPx2.2dx35m / m</td><td>Random</td>
<td> 3</td><td>Interlaced</td><td colspan="2">by spinning</td><td colspan="2">PPx1.5dx45m / m</td><td>Parallel</td>
<td> 4</td><td>do</td><td></td><td></td><td colspan="2">Acetate bundle</td><td>Parallel</td>
<td>Not.</td><td>Base weight</td><td colspan="3">Resistance (kg / 2.5 cm)</td><td colspan="2">Elongation (%)</td>
<td></td><td>(g / m<sup>2</sup>)</td><td>MD</td><td>CD</td><td>MD / CD</td><td>MD</td><td>CD MD / CD</td>
<td> 1</td><td> 30</td><td> 5,3</td><td> 2,2</td><td> 2,4</td><td> 30</td><td> 48 1,6</td>
<td> 2</td><td> 32</td><td> 3,9</td><td> 0,6</td><td> 6,5</td><td> 21</td><td> 70 3,3</td>
<td> 3</td><td> 35</td><td> 3,7</td><td> 0,8</td><td> 4,6</td><td> 20</td><td> 230 11,6</td>
<td> 4</td><td> 40</td><td> 5,2</td><td> 0,4</td><td> 13</td><td> 15</td><td> 290 19,3</td>
As described above, the absorbent element of the present invention is constructed by securing the non-woven fabric to at least one of the faces of the highly stretchable, liquid-impermeable elastic sheet, continuously in a first direction and intermittently. in a second direction perpendicular to the first direction along the fastening portions, forming a plurality of channels extending parallel to each other between the nonwoven fabric and the elastic sheeting and positioning the absorbent elements in the channels. Therefore, the absorbent element has excellent elasticity and water impermeability characteristics. Likewise, the nonwoven fabric of the absorbent element provides excellent flexibility and breathability characteristics. Consequently, the present absorbent element is highly suitable for use in a variety of articles that come into contact with the skin during use, such as disposable diapers, sanitary napkins and the like, which are applied to the wearer's waist or cross.
It is to be understood that the specific embodiment illustrated herein should not be considered in any way as a limitation of the present invention. The present description is intended to cover, by means of the appended claims, all those modifications that fall within the scope of said claims.
Contents5
11 sheets
Sheet 1 Sheet 2 Sheet 3 Sheet 4 Sheet 5 Sheet 6 Sheet 7 Sheet 8 Sheet 9 Sheet 10 Sheet 11
14 members in 5 offices
Priority claims4
| Document | Office | Kind | Date |
|---|---|---|---|
| 19920236342 | Japan | – | |
| 19920236340 | Japan | – | |
| 23634292 | Japan | A | |
| 23634092 | Japan | A |
Members14
| Document | Office | Kind | |
|---|---|---|---|
| CA2103992A1 | Canada | A1 | |
| JPH0690977A | Japan | A | |
| JPH0690979A | Japan | A | |
| EP0591647A2 | European Patent Office (EPO) | A2 | |
| EP0591647A3 | European Patent Office (EPO) | A3 | |
| CA2103992C | Canada | C | |
| EP0591647B1 | European Patent Office (EPO) | B1 | |
| DE69328957D1 | Germany | D1 | |
| ES2149185T3This record | Spain | T3 | |
| DE69328957T2 | Germany | T2 | |
| JP3375153B2 | Japan | B2 | |
| EP0591647B2 | European Patent Office (EPO) | B2 | |
| DE69328957T3 | Germany | T3 | |
| JP3667353B2 | Japan | B2 |
1 legal event, as the office reported them to INPADOC
Events
| Event | Code | |
|---|---|---|
| Definitive protectionFG2A | FG2A |
Numbers
- Publication
- 2149185
- Application
- 93112868
Titles2
- Spanish
- ARTICULO ABSORBENTE ESTIRABLE.
- English
- ABSORBENT STRETCHABLE ITEM.
Classification
- CPC, 13
- A61F13/5148
- A61F13/49011
- A61F13/49017
- A61F13/496
- A61F13/51464
- A61F13/51484
- A61F13/515
- A61F13/53
- A61F2013/15991
- A61F2013/4568
- A61F2013/49022
- A61F2013/49023
- A61F2013/51429
- IPC, 1
- A61F13 15