MXPA01001767A - A method for cutting and sealing an absorbent member - Google Patents

Abstract

A method for wrapping, sealing, and cutting an absorbent member. A superabsorbent material movement obstruction agent (120) is applied to a wrap web (105). The wrap web (105) is combined with a core web (110) including a fibrous material and superabsorbent material to form an absorbent member web (140). The absorbent member web (140) is cut into discrete absorbent members (26). The absorbent member of the present invention is particularly useful in disposable absorbent articles.

Description

CAMP @ «OF THE INVENTION This invention relates to a method for wrapping, cutting and sealing an absorbent member, and more particularly to a method for wrapping, cutting and sealing an absorbent member that is suitable for use as an absorbent member in a disposable absorbent article. .

BACKGROUND OF THE INVENTION Absorbent webs comprising fiber masses, i.e., fibrous web, are well known in the art. These webs can imbibe liquids, such as fluids discharged from the body, both by an absorption mechanism where the The fluid is captured by the fiber material itself and by a capillary action mechanism where the fluid is acquired by means of, it is distributed through and is stored in the capillary interstices between the fibers. One means to improve the absorbency characteristics of these fibrous web structures is to incorporate superabsorbent material therein, such as the polymeric gelling material (also referred to as superabsorbent polymers of hydrogel-forming material, etc.) which imbibes the fluid. The superabsorbent material serves to retain fluid such as liquids discharged from the body. An absorbent structure of this type in which gel forming materials are incorporated in the form of particles in the fibrous webs is disclosed by Weisman and Goldman, in U.S. Patent No. 4,610,678 issued September 9, 1986 The improvement in absorbency provided by the incorporation of gelling absorbent materials has allowed the realization of absorbent articles, such as disposable diapers, which employ relatively thin absorbent members and absorbent articles. which are, therefore, relatively thin products. Despite the existence of the absorbent members as described above, there remains the need to provide absorbent members that reduce and preferably eliminate the phenomenon referred to as gel on the skin. The gel on the foot! it is the situation where the gelling absorbent materials escape from the absorbent member and travel through the liner on the body side or upper sheet of the absorbent article where they come into contact with the wearer's skin. In the continuous laying operations of the prior art, the fibers and the superabsorbent materials are mixed together in a continuous web. The continuous web is then cut into individual absorbent members or cores. The individual absorbent members are then placed between the liquid-permeable topsheet and a liquid-impermeable backsheet to form an absorbent article.

Unfortunately, this configuration provides an unsatisfactory product as the gelling absorbent material easily penetrates through the upper sheet creating unacceptable amounts of gel on the skin. One solution to the previous continuous laying operation was to place another weft, such as a tissue or a non-woven web over the top of the continuous web and then cut both the tissue and the continuous web into individual members comprising the core and the tissue The individual members were then placed in the product with the tissue placed between the upper sheet and the absorbent member substantially preventing the gelling absorbent material from escaping from the uppermost surface of the absorbent member and thereby reducing the amount of gel on the absorbent member. the skin.

SI.? AtiagAj «» íifejáMl-b-A »- ... ., * > 7L »¿. > , A ^ fe¡ - ^. ^^^ x ^ Si ^ 'SSS ^^ Unfortunately, when for example, the tissue and the continuous web are cut into individual members, the ends of the absorbent member are left open, i.e. the ends of the absorbent member are not covered by the tissue, allowing the gelling absorbent material to escape through the ends of the absorbent member. It is an object of this invention to provide a method for cutting and sealing an absorbent member via a continuous positioning operation which avoids the problems of the gel on the skin.

BRIEF DESCRIPTION OF THE INVENTION The invention is a method for wrapping, cutting and sealing an absorbent member. The absorbent member comprises a core web and a wrapper web. The core web is a fibrous material and a superabsorbent material and has a first side edge and a second side edge, the web has an inner surface and an outer surface. The method of the present invention comprises the steps of applying a blocking agent of movement of the superabsorbent material to the wrapping web, combining the wrapping web with the core web such that the inner surface of the wrapping web is giving towards the core web to form a weft of absorbent member, to fold the web of wrap around the first side edge and / or the second side edge of the core web, to cut the weft of the absorbent member into discrete absorbent members. The individual absorbent members preferably form an absorbent member in a disposable absorbent article and are placed between the liquid permeable topsheet and a liquid impermeable backsheet.

BRIEF DESCRIPTION OF THE DRAWINGS Although the description concludes with the claims that point out in a particular way and claim differently from the present invention, it is believed that it will be better understood by the following drawings taken in combination with the accompanying description, wherein similar components are given with the same reference number. Figure 1 is a plan view of an absorbent article comprising an absorbent member made according to the process of the present invention. Figure 2 is a schematic perspective view of a first embodiment of the method of the present invention. Figure 3 is a schematic perspective view of a second embodiment of the method of the present invention.

DETAILED DESCRIPTION OF THE INVENTION The method of the present invention is particularly suitable for manufacturing absorbent members that are used in disposable absorbent articles. As used herein, the term "absorbent article" refers to devices that absorb and contain exudates from the body, and, more specifically, refers to devices that are placed against or close to the user's body to absorb and contain the various exudates discharged from the body. The term "disposable" is used herein to describe absorbent articles that are not intended to be washed or restored or reused in another way as an absorbent article (ie, they are intended to be discarded after a simple use , Y, preferably, to be recycled, composted or otherwise disposed of in an environmentally compatible manner). A "unitary" absorbent article refers to absorbent articles that are formed of separate parts joined together to form a coordinated entity such that separate manipulated parts are not required as a separate support and liner. As used herein the term "attached" encompasses configurations by which one element is directly secured to the other element by fixing the element directly to the other element, and configurations by which one element is indirectly secured to another element by fixing the element to a member or intermediate members who in turn are fixed to the other element. A preferred embodiment of a unitary absorbent article comprising an absorbent member made by the method of the present invention is the unitary disposable absorbent article, diaper 20, shown in Figure 1. As used herein, the term "diaper" refers to an absorbent article generally worn by incontinent babies and adults and carried around the user's lower torso. However, it should be understood that the present invention is also applicable to other absorbent articles such as incontinence briefs, incontinence undergarments, absorbent inserts, diaper liners and liners, feminine hygiene garments, and the like. With reference to Figure 1, an absorbent article such as a diaper 20, generally comprises a liquid-permeable topsheet 22, a liquid-impermeable backsheet 24 bonded to the topsheet 22.; and an absorbent member 26 intermediate the topsheet 22 and backsheet 24. The diaper 20 further preferably comprises a waist front region 36, a waist back region 38, a crotch region 37 positioned between the waist front region 36 and the rear waist region 38, elasticized folds for the leg 28, ear flaps 30, an elastic waist feature 32 and a fastening system 34 comprising at least one t ^^ s ^^? ¿^ ^^^^^^^^^^^^^^^^^^^^^^^^ J ^^^^ Ü ^^^^^^^^^^^ ^^^^^^^^^^ í tape tab 40. an example of a suitable absorbent article to which can be inserted the absorbent member of the present invention is described more fully and completely in the patent US No. 5,151,092 issued to Buell et al. On September 29, 1992. The absorbent member 26 of the present invention can be produced in the apparatus 110, as shown in Figure 2. In a preferred embodiment, the apparatus 100 is integrated in the manufacturing line of the disposable absorbent article such that the absorbent member 26 of the present invention can be manufactured "in line". (As used, the term "integrated" means interconnected process modules that operate concurrently to produce finished products from source materials). The term "online" is used to refer to the process of manufacturing the absorbent members of the present invention on an apparatus that is integrated with a manufacturing line that produces the disposable absorbent articles to which are attached the tape tabs. ) the absorbent member 26 of the present invention comprises a core member and a member wrapping are cut from a web of core 110 and a frame wrap 105, respectively, during manufacture of the absorbent member 26 of the present invention . Examining the apparatus 100 in greater detail, a wrapping web 105 having an internal surface 106 and an external surface 107 is provided. A movement obstructing agent of the superabsorbent material 120 is applied to the wrapping web 105 by a dispensing device 130 of the movement obstruction agent of superabsorbent material. Preferably, the motion obstructing agent of the superabsorbent material 120 is applied to the inner surface I of the wrapper 105. A core frame 110 having a first lateral edge 11 1 and a second side edge 112 is provided and combine with wrapping web 105 in such a way that internal surface 106 is facing the weft of core 110, thereby forming a weft of absorbent member 140. The weft of absorbent member 140 is fed to a cutting device 300 which cuts the weft of absorbent member in discrete absorbent members 26. The weft of core 110 comprises fibrous material and superabsorbent material. The fibrous material may comprise cellulose fibers, in the form of modified cellulose fluff fibers such as hardened cellulose fibers; synthetic fibers such as those made of cellulose acetate, polyvinyl fluoride, polyvinylidene chloride, acrylics, polyvinyl acetate, non-soluble polyvinyl alcohol, polyethylene, polypropylene, polyamides (such as nylon), polyesters, two-component fibers, three components, mixtures thereof and the like. Preferred synthetic fibers have a denier of about 3 denier per filament to about 25 denier per filament, more preferably from about 5 denier per filament to about 15 denier per filament. Also preferably, the surfaces of the fiber are hydrophobic or treated to be hydrophilic. Suitable superabsorbent materials include but are not limited to discrete particles of gelling absorbent material and fibrous superabsorbent material such as grafted acrylate fibers and modified superabsorbent fibers. The superabsorbent material can be in any form which can be incorporated in a web or sheet form flexible frame 110. The superabsorbent to be in contact with fluids such as water or body fluids material absorbs such fluids. The superabsorbent material is typically in the form of discrete particles of gelling absorbent material. Suitable agents for the motion obstructing agent of the superabsorbent material 120 include, but are not limited to, polymer solutions or emulsions, both natural (for example, natural rubber latex) and synthetic, in which the liquid is water or any other suitable liquid or liquid mixtures. Running water emulsions are preferred and highly preferred are common water emulsions of acrylic or vinyl adhesive polymers. Other suitable agents for the movement obstructing agent of the superabsorbent material also include thermoplastic polymers or polymer compositions having a softening point, as determined by the ASTM E28"ring and ball" method, in the range of 50 ° C to 50 ° C. 300 ° C. Preferably this thermoplastic polymer or polymer composition is a wax or a composition having at least 50% by weight of a wax, such as wax or composition preferably having a softening point of less than about 180 ° C. More preferably, this thermoplastic agent (this being a polymer, a wax or a composition derived therefrom) is or contains at least 50% by weight of a copolymer having at least one of its co-monomers , acrylic acid, acrylamide, acrylic esters and / or derivatives thereof. Figure 3 shows an alternative embodiment of the method of the present invention which further comprises the step of folding the wrapping web 105 around the first side edge 111 and / or the second side edge 112 of the core web 110 by means of the device bend 200. Preferably, the first side edge of the wrapping web is joined to the second side edge of the core wrap after bending such that the wrapping web transversely wraps the core web. The movement obstruction agent of the superabsorbent material is preferably not applied to the total wrapping web, but only in discrete, separate areas. Although the motion obstruction agent of the superabsorbent material provides the benefit of obstructing the movement of the material Super absorbent through the cut end of the absorbent members, this may have some negative effects if applied to the entire wrapping web. For example, the agent may increase the stiffness of the absorbent member in a manner that becomes uncomfortable for the user if applied to the entire wrapping fabric. The agent can inhibit some of the absorbent properties of the absorbent member and therefore negatively impact the absorbent article which employs an absorbent member having the agent applied to the entire wrapping fabric. In this way, in order to achieve the desired clogging effect of the movement of the superabsorbent material through the cut end of the members Absorbents without negatively impacting the performance, comfort, or other properties and characteristics of the absorbent members and an absorbent article employing such member, the movement obstructive agent is applied. superabsorbent material to the wrapping web in only discrete, spaced zones Preferably, the zones extend over the full width of the wrapping web.

In another embodiment of the method of the present invention, the weft of the absorbent member comprising a wrapping web, a core weft are combined with a second wrapping web having an inner surface and an outer surface such that the The core web is placed between the wrapping web and the second web, the internal surface of the second web giving to the kernel frame. The wrapping web and / or the second wrapping web are preferably folded around the first side edge and / or the second side edge of the absorbent web in such a way that the side edges of the wrapping web and the second web of wrapping overlap. More preferably, the side edges of the first wrapping frame and the second wrapping frame are joined together for transversely wrapping the core web.

Preferably, the motion-obstructing agent of the superabsorbent material is further applied to the second screen more preferably to the internal surface of the second screen.

Claims (3)

REIVINDI, CA'Cj, IONES

1. A method for cutting and sealing an absorbent member (26), the absorbent member comprising a core web comprising a fibrous material and a superabsorbent material and having a first side edge and a second side edge, a weft wrap having a surface external and an internal surface, the method comprising the steps of: applying an obstruction agent of movement of the superabsorbent material to said wrapping frame; combining the wrapping web with said core web such that the inner surface is facing the core web to form a web of absorbent member; and cutting said weft of absorbent member into discrete absorbent members. The method according to claim 1, wherein the superabsorbent material movement obstructing agent is applied to the inner surface of the wrapping fabric. The method according to claim 1, further comprising a step of folding the wrapping web around the first side edge and / or the second side edge. The method according to claim 3, wherein the wrapping frame has a first side edge and a second side edge and the method further comprises the step of wrapping transversely the core web by joining the first side edge of the wrapping web to the second lateral edge of the core frame. The method according to claim 1, wherein the wrapping frame has a first side edge and a second side edge and said method further comprises the steps of providing a second wrapping web having an inner surface and an outer surface , wrap transversely the ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ^^^^^ = ^^^^^^^^^^^ core frame joining the first lateral edge of the wrapping web and the second lateral edge of the wrapping web to said second wrapping web in such a way that the inner surface of the second wrapping web is facing the core web. 6. The method according to claim 5, wherein the method further comprises the step of applying a blocking agent of movement of the superabsorbent material to the second wrapping fabric. The method according to claim 6, wherein the movement obstruction agent of the superabsorbent material is applied to the 10 internal surface of the second wrapping pattern. 8. The method according to any of the preceding claims, wherein the motion obstructing agent of! Superabsorbent material is a material selected from the group of polymeric solutions or emulsions 15 9. The method according to claim 8, wherein the polymeric solutions or emulsions are either natural or synthetic. The method according to any one of claims 1 to 7, wherein the motion obstructing agent of the superabsorbent material is a thermoplastic polymer or a polymeric composition having a point of 20 softening within the range of between 50 ° Celsius and 300 ° Celsius. The method according to claim 10, wherein the thermoplastic polymer or the polymer composition is a wax or a composition containing at least 50% by weight of a wax.