MXPA98001969A - Procedure for elaborating disposable items in an oposic configuration - Google Patents

Abstract

The present invention relates to a process for making disposable articles, such as absorbent sanitary napkins, having a side facing the garment which is provided with an adhesive to temporarily adhere the article to a wearer's garment. A release liner covers the adhesive on the side facing the garment for the purpose of protecting it before use. The release liner has at least one article with its adhesive side attached to opposite sides of the release liner, such that a release liner is preferably used for two items

Description

PROCEDURE FOR ELABORATING DISPOSABLE ARTICLES IN AN OPPOSITION CONFIGURATION FIELD OF THE INVENTION The present invention relates to a process for making disposable absorbent articles, such as absorbent sanitary napkins, having a garment-facing side and provided with an adhesive to temporarily adhere the article to the undergarment of a garment. user. In particular, the present invention relates to a process for making disposable absorbent articles having a release liner that covers the adhesive on the side facing the garment in order to protect it before use. The present invention is an improvement over the use of the release liner for this purpose, having at least one article with its adhesive side attached to the opposite sides of the release liner, such that a release liner for two is preferably used. articles.

BACKGROUND OF THE INVENTION In general, the disposable absorbent articles according to the present invention have an adhesive on their side that faces the garment in order to adhere them to the wearer's garment of these articles. This adhesive is adopted to keep the article essentially fixed in relation to the garment and / or the user and thus improves the utility of the particular article. In order to accomplish this objective, the adhesive is typically protected before use of the articles, against staining, premature adhesion to any particular surface and especially to self-adhesion, which usually results in a condition of the article which makes it unsuitable for use. This protection before the use of the adhesive on the side facing the garment in an article is provided by a release liner. The release liner can be provided by any desirable material in this context, especially waxed paper release liners, papers that are coated with a release agent such as silicone on the side that contacts the waxed paper are well known in the art. the adhesive, release liners extending beyond the periphery of the absorbent article are also well known for bending and wrapping and enclosing the absorbent article. These release liners are often made of polymeric film material such as polyethylene film, polypropylene film and the like. Also release liners of woven or non-woven material have been reported to provide useful protection for the adhesive from premature soiling or harmless adhesion to an unwanted surface. None of the references known to the applicant, however, disclose a process for making disposable absorbent articles having a release liner that is used on both sides having the respective adhesive side of a fixed article to reduce the amount of the release liner for up to 50%. It is therefore an object of the present invention to provide a method for making disposable absorbent articles, which have a reduction of up to 50% of the release liner by joining the articles to both sides of the release liner. It is in particular an object of the present invention to provide a method for making sanitary napkins or panty liners having an adhesive on their side that faces the garment in an opposing pad construction wherein the sanitary napkins or linings of the sanitary napkin Pants are joined on both sides of a single side of the release liner in correspondence of the products, and preferably are packed in groups of plus two sanitary napkins or two panty liners per package.

DESCRIPTION OF THE INVENTION Many designs for absorbent articles disposable in the art are known. Disposable absorbent articles are used as sanitary napkins, catamenial products, panty linings, adult incontinence products for light and medium incontinence or incontinence of children. Disposable absorbent articles are also contemplated in the present invention, particularly those that may be used in pairs such as disposable absorbent shoe inserts, disposable absorbent sweat pads or other disposable absorbent products. In addition, the present invention may be applicable to other disposable products that are not inherently absorbent but cushioning of particular parts of the human body such as, for example, chair arm pads, or knee pads that may be applied by the use of an adhesive to the garment. of a user. As mentioned above, the present invention relates to a wide variety of products that have utility for absorbing liquids or cushioning part of the user's body and which are applied to the desired location by means of a temporary fixation adhesive. The articles mainly contemplated by the applicant are, however, sanitary napkins, catamenial products, linings for panties and inserts for incontinence. For all these disposable items, reference should be made to either the generic term of disposable articles or sanitary napkins. Disposable articles according to the present invention have a garment-facing side and a garment-facing adhesive on the side facing the garment. The adhesive is provided in order to attach the disposable article to a user's undergarment, to improve the utility of the article. The adhesive on the side facing the garment of the article is protected by a release liner before use. The release liner has first and second surfaces, both of which are provided with the ability to easily delaminate the adhesive on the articles. At least one disposable article is placed on both of the first and second surfaces of the release liner and is joined by means of the adhesive strength of the adhesive on the side facing the garment to its respective sides of the release liner. Preferably two disposable articles are fixed in particular, in correspondence with the first and second surfaces before being used. The term "in correspondence" in this respect, refers to disposable articles that are placed on each side of the release liner, such that its common periphery is essentially identical to its individual periphery. The adhesive can be provided in any desired form on the garment facing side of the disposable article or sanitary napkin. For example, this can be applied as a longitudinal strip that extends to the total length of a sanitary napkin, or it can be shorter than the total length. Depending on the application process, this can extend to the total width perpendicular to the length of the article or leave the sides of the article free of adhesive. Also, a multitude of adhesive or random strips or a pattern of designed adhesive can be provided on the side facing the garment of a sanitary napkin. It is also possible to have the adhesive provided in a particular form such as a continuous strip that follows the periphery of the sanitary napkin with a short distance to that of the periphery or even directly adjacent to that periphery, while leaving the center of the sanitary napkin adhesive free.

It is most desirable that the release liner be as short as possible while maintaining the easy manufacturing capacity of the sanitary napkin. In particular, the release liners provided as continuous bands having a width that does not exceed the minimum dimension of the sanitary napkin perpendicular to its longitudinal axis have been found useful. Obviously the adhesive in this case is also applied in an area that does not exceed the minimum dimension perpendicular to the longitudinal axis of the sanitary napkin. The sanitary napkins are placed on this continuous band of the release liner in correspondence on both surfaces of the release liner and then cut at their longitudinal ends. In this manner a sanitary napkin sandwich, release liner, sanitary napkin is formed. The release liner ideally does not exceed beyond the sanitary napkin after it has been trimmed. For the consumption of material, the adhesive and the release liner can be even shorter than the sanitary napkin. Typically, the release liner under these conditions will be slightly larger in width and length than the adhesive, in order to allow a certain amount of variation in the placement when the sanitary napkins are manufactured in opposition. Since the release liner is shared by two sanitary napkins, an individual packing of these products is no longer possible. The option for double packs of articles is particularly interesting for these articles, which are used in pairs. For sanitary pads that are used individually, double packs may also be convenient, for example, to carry them when you leave the house. However, sanitary napkins or panty liners are typically stored and used in the same place by an individual user. In this situation, a bulky package of several sanitary napkins placed in opposition is attractive. This way of packing, allows the use, of a pair of sanitary towels in opposition and return to a sanitary napkin with the release liner that remains in the place inside the package, for example, in a cardboard box and the subsequent use of the same way is known from the sanitary napkins typical of the state of the art. A preferred process for making disposable absorbent articles according to the present invention comprises the steps of providing a continuous stream of pairs of disposable absorbent articles. This continuous stream of pairs of disposable absorbent articles consists of a first and second continuous stream of disposable absorbent articles in a side-by-side relationship such that the longitudinal ends of the articles are in correspondence with one another in pairs. It is also possible to individually provide a first and a second continuous stream of disposable absorbent articles, which, however, require careful alignment in order to obtain the desired side-to-side relationship of the pairs of disposable absorbent articles when the streams are subsequently combined. Independent of the same, a continuous stream of release liners having a first and a second release surface is provided. The next step is to apply the adhesive. The adhesive can be either applied to the garment facing side of the articles or to the release liner release surface or combinations thereof. It is also not necessary for the adhesive to be applied simultaneously to both articles of each pair. An additional step is to join the first and second stream of the absorbent articles with the surface of the release liner or vice versa. Again, this can be done simultaneously or consecutively depending on the particular situation as will be readily appreciated by those skilled in the art. The step of attaching the articles to the release liner requires careful alignment of the products (the adhesive if applied to the release liner). This is greatly simplified if a single stream of pairs of disposable absorbent articles is used, since this current only needs to be folded around the release liner ensuring that the items are properly aligned. Therefore, the sanitary towel construction is formed in opposition as discussed above in a continuous stream of articles and release liner. As a final step, the articles and the release liner have to be separated in such constructions from disposable absorbent articles as opposed to desired. Particularly for pantiliners, it has been found that it can be used at the end by a die (or other means of total peripheral cutting) to create the periphery of the pantiliners. If the pantiliners are then constructed with identical compositions all along their surface (without variations in the lateral or longitudinal direction of any of the layers of the pantiprotector) the alignment between the pairs of pantiliners is automatically obtained in the final cut of the pantiliners . Typically the adhesive is applied by coating (slot coating, coating or curtain spray) in a continuous manner as an endless strip or line. Alternatively, the adhesive can be applied by an inventive process, again either as a continuous printing of an adhesive strip or any desired configuration and contour of the adhesive within the periphery that faces the garment of the disposable absorbent article. . The following describes the typical components of sanitary napkins.

However, many variations of materials and the typical design of sanitary napkins are possible within the scope of the present invention, which is defined by the claims and is essentially related to the use of both sides of a release liner primarily to optimize the consumption of the material. Typically, a sanitary napkin or pantiliner comprises a topsheet that forms the opposite side of the garment facing surface and that is permeable to liquid. In addition, an absorbent core comprising one or more components is associated with the topsheet in liquid communication. Finally, a back sheet that forms the surface facing the garment in a sanitary napkin or in a panty lining, and carries the fastening adhesive of the pantyhose is also included.

These three components are described in more detail below.

TOP SHEET The top sheet is docile, soft feeling and non-irritating to the user's skin. Also the upper sheet can have elastic characteristics that allow it to stretch in one or two directions. In addition, the top sheet is permeable to fluids allowing fluids (eg, menstruation and / or urine) to easily penetrate through their thickness. A suitable top sheet can be manufactured from a wide range of materials such as woven and non-woven materials; polymeric materials such as thermoplastic films formed with openings; plastic films with opening; and hydroformed thermoplastic films; porous foams, cross-linked foams, cross-linked thermoplastic films; and thermoplastic canvases. Suitable woven and nonwoven materials may be formed of natural fibers (for example, cotton or wood fibers), synthetic fibers (for example polymer fibers such as polyester, polypropylene or polyethylene fibers), or from a combination of fibers natural and synthetic). The preferred top sheets for use in the present invention are selected from the top non-woven top sheets and top sheets of film formed with aperture. Films formed with openings are especially preferred for the upper sheets, because they are permeable to body exudates and still non-absorbent and have a reduced tendency to allow fluids to grind back through and rewet the user's skin. In this way, the surface of the formed film that is in contact with the body remains dry, thus reducing body soiling and creating a more comfortable feeling for the user. Suitable formed films are described in U.S. Patent 3,929,135, U.S. Patent 4,324,246; U.S. Patent 4,342,314, U.S. Patent 4,463,045; and United States Patent 5,006,394. Top sheets of film formed with particularly preferred micro apertures are described in U.S. Pat. Nos. 4,609,518 and U.S. Patent 4,629,643. The preferred top sheet for the present invention comprises the formed film described in one or more of the prior United States patents and marketed in sanitary napkins by The Procter & Gamble Company of Cincinnati, Ohio, as "DRI-WEAVE". The upper sheets having a homogeneous distribution of liquid passage guides, but only in the part of the upper sheet comprising the liquid passageways are also useful in the present invention. Typically, these upper sheets would tend the liquid passageways oriented such that they result in a centrally permeable and peripherally impermeable upper liquid sheet. The body surface of the formed film top sheet can be hydrophilic to help the liquid transfer through the top sheet faster than if the body surface were not hydrophilic. In a preferred embodiment, surfactant is incorporated into the polymeric materials of the formed film topsheet as described in United States Patent Application Serial No. 07 / 794,745"Absorbent article having a nonwoven film cover sheet and with aperture ", filed November 19, 1991. Alternatively, the body surface of the topsheet can be rendered hydrophilic by treatment with a surfactant such as described in U.S. Patent 4,950,254.

ABSORBENT NUCLEUS The absorbent core does not have to be a single entity. This may include the following components: (a) optionally a primary fluid distribution layer preferably attached with a secondary optional fluid distribution layer (b) a fluid storage layer; (c) optionally a fibrous layer ("dedusting") lying on the storage layer; and (d) other optional components. to). Primary / secondary fluid distribution layer An optional component of the absorbent structure according to the present invention is a primary fluid distribution layer, a secondary fluid distribution layer. The primary distribution layer is typically below the top sheet and is in fluid communication with it. The top sheet transfers the acquired fluid to this primary distribution layer for final distribution to the storage layer. This transfer of fluid through the primary distribution layer occurs not only within the thickness, but also along the longitudinal and wide directions of the absorbent product. The also optional, but preferred secondary distribution layer typically lies below the primary distribution layer and is in fluid communication with it. The purpose of this secondary distribution layer is to quickly acquire the fluid from the primary distribution layer and transfer it rapidly to the underlying storage layer. This helps the fluid capacity of the underlying storage layer to be fully utilized. b) Fluid Storage Layer Placed in fluid communication with, and typically underlying the primary or secondary distribution layers, is a fluid storage layer. The fluid storage layer may comprise gelling absorbent material, any usual absorbent material or combinations thereof. It preferably comprises gelling absorbent materials usually referred to as "hydrogel" "superabsorbent", hydrocolloid materials. These gelling absorbent materials are capable of absorbing large quantities of aqueous body fluids, and are also capable of retaining these absorbed fluids under moderate pressures. These gelling absorbent materials may be in the form of discrete particles. The gelling absorbent materials can be dispersed homogeneously or non-homogeneously in a suitable carrier. Suitable carriers include cellulose fibers, in the form of speck, tissue or paper, as can conventionally be used in absorbent cores or in the form of tissue in a single layer or multiple layers. Modified cellulose fibers such as hardened cellulose fibers can also be used. Synthetic fibers can also be used and include those made of cellulose acetate, polyvinyl fluoride, polyvinylidene chloride, acrylics (such as Orion), polyvinyl acetate, non-soluble polyvinyl alcohol, polyethylene, polypropylene, polyamides (such as nylon) , polyesters, two-component fibers, three-component fibers, mixtures thereof and the like. Preferably, the surfaces of the fiber are hydrophilic or are treated to be hydrophilic. The storage layer may also include filling materials, such as Perlite, diatomaceous earth, Vermiculite, etc., which reduce the problems of rewetting. If dispersed in a non-homogeneous manner in a carrier, the storage layer may be locally homogeneous, but have a distribution gradient in one or several directions within the dimensions of the storage layer. The inhomogeneous distribution can also refer to the laminates of the carriers that enclose the gelling absorbent materials partially or totally. Laminates are preferred for panty liners due to their thinness. The gelling absorbent materials suitable for use in the present, most will often comprise a substantially insoluble, slightly crosslinked, partially neutralized polymeric gelling material. This material forms a hydrogel upon contact with water. These polymer materials can be prepared from acid-free, unsaturated polymerizable monomers that are well known in the art. The unsaturated acidic monomers suitable for use in preparing the gelling absorbent polymeric material used in this invention include those listed in U.S. Patent No. 4,654,039, reissued as RE 32,649. Preferred monomers include acrylic acid, methacrylic acid, and 2-acrylamido-2-methyl propane sulfonic acid. Acrylic acid by itself is especially preferred for the preparation of the polymeric gelling material. Ordinary absorbent materials are those described as a carrier above, and may be in particular materials such as cellulose fibers, tissue or creped cellulose wadding. c) Optional fibrous layer "dedusting" An optional component for inclusion within the absorbent cores according to the present invention is a fibrous layer adjacent to, and typically underlying the storage layer. This underlying fibrous layer is typically referred to as a "dedusting" layer since it provides a substrate on which the absorbent gelling material is deposited in the storage layer during the manufacture of the absorbent core. In fact, in those examples where the gelling absorbent materials are in the form of macrostructure such as fibers, sheets or strips, this fibrous "dedusting" layer need not be included. However, this "dedusting" layer provides some of the additional fluid handling capabilities such as rapid fluid flow along the length of the pad. d). Other optional components of the absorbent structure The absorbent cores according to the present invention can include other optional components normally present in absorbent webs. For example, a reinforcing fabric may be placed within the respective layers, or between the respective layers of the absorbent cores. These reinforcement canvases should be of such configuration as they do not form interfacial barriers for fluid transfer, especially if they are placed between the respective layers of the absorbent core. However, reinforcing canvases are not usually required for the absorbent structures according to the present invention. Another component that can be included within the absorbent core according to the present invention and preferably is provided closer to or as part of the primary or secondary fluid distribution layer are the odor control agents. Typically, activated carbon coated with or in addition to other odor control agents, in particular suitable zeolite or clay materials, are optionally incorporated in the absorbent core. These components can be incorporated in any desired form but are often sensed as discrete particles.

BACK SHEET The backsheet prevents the exudates absorbed and contained within the absorbent core from moistening the articles that come into contact with the sanitary napkin such as underpants, pajamas and undergarments. The backsheet is preferably impervious to liquids (eg, menstruation and / or urine and is preferably manufactured from a thin plastic film, although other flexible liquid-impermeable materials may also be used.) As used herein, The flexible term refers to materials that are docile and that will easily conform to the shape and general outline of the human body.The backsheet may also have elastic characteristics that allow it to stretch in one or two directions.The backsheet may comprise a woven material or non-woven, polymeric films such as polyethylene or polypropylene thermoplastic films, or mixed materials, such as a film-coated nonwoven material.Preferably, the backsheet is a polyethylene film having a thickness of from about 0. 012 mm to approximately 0.051 mm. Exemplary polyethylene films are manufactured by Clopay Corporation of Cincinnati, Ohio, under the designation P18-0401 and by Ethyl Corporation, Visqueen Division of Terre Haute, Indiana, under the designation XP-39385. The backsheet is preferably embossed and / or finished without gloss to provide a fabric-like appearance. In addition, the backsheet can allow the vapors to escape the absorbent structure (ie, be breathable) while still preventing the exudates from passing through the backsheet.

ADHESIVE CLIP ON THE PANTS AND RELEASE LINES The backsheet typically forms the surface facing the garment on which the panty fastener is placed. The panty fastener adhesives may comprise any adhesive or glue used in the art for such purposes, with pressure sensitive adhesives being preferred. Suitable non-extensible adhesives are Century A-305-IV manufactured by Century Adhesives Corporation, Instant Lock 34-2823, manufactured by National Starch, 3 Sigma 3153 manufactured by 3 Sigma, and Fuller H-2238 ZP manufactured by H.B. Fuller Co. Suitable adhesives are also described in U.S. Patent 4,917,697. Extendable adhesives suitable for use as panty fasteners include extendable adhesives, per se, and extensible adhesive / backsheet combinations. Any of the extensible adhesives known in the art can be used. Suitable extensible adhesive / back adhesive combinations are, for example, the non-extensible adhesive used on an extensible backsheet material such as 3 Sigma 2474 available from Anchor Continental, Inc., Division 3 Sigma, Covington, Ohio; elastically stretchable adhesive films such as Findley adhesive 198-338, or an elastically stretchable adhesive film known as 3M XPO-0-014 available from the Minnesota Mining and Manufacturing Company of St. Paul, Minnesota; or sprayed adhesives such as 3M 1442 adhesive on a low modulus elastic film. Other panty fastener adhesives are known from PCT International Patent Publication No. WO 92/04000; WO 93/01783 and WO 93/01785. Sanitary towels containing extensible adhesives will typically only be capable of extension between non-extensible adhesive patches. Therefore, if non-extensible adhesives are used, they are preferably applied in intermittent patterns such as, for example, intermittent spots, intermittent strips or stripes, random filamentary patterns or by design to allow the sanitary napkin to extend. If, on the other hand, the adhesive is extensible, the adhesive can be applied in continuous or intermittent patterns. Before using the absorbent article, the panty fastener adhesive is protected from contamination and glued to any surface where this is not desired by a protective release liner, such as release paper coated with silicone, a plastic film or any another removable cover. The protective release liner may be any of the release liners known in the art. In fact, many of the commercially available release liners can simply be used by making the second surface releasable by the same method and in the same manner as it is ordinary with the first surface. Some of the release liners are already provided as double-sided release liners, due to the simplicity of the process to make them releasable. Suitable release liners are, for example, described in U.S. Patent 4,917,697. Non-limiting examples of commercially available release liners suitable to be modified for the purposes of the present invention are, for example, BL30MG-A Silox E1 / 0 and BL30MG-A Silox 4P / 0, both of which are manufactured by the corporation Acrosil. Other release liner materials are those known from sanitary napkins individually wrapped but which, nevertheless, provide their wrapping function, can also develop the function of the release liner in an opposing pad construction. These materials are described in detail in U.S. Patent 4,556,146 or in PCT Application WO 93/09743.

OPTIONAL COMPONENTS OF ABSORBENT ITEMS Optionally, the absorbent product of the present invention can comprise all those components that are known to be typical for the use of the particularly intended product. For example, catamenial products, panty liners and sanitary napkins often comprise components such as wings, for the purpose of better placement performance and protection against staining. The elasticization of the leg by one or more elastic threads is also common in the technique of absorbent products. In general, all the components typically used in absorbent products may also be comprised in the absorbent products according to the present invention.

Claims (9)

1. - Process for producing disposable absorbent articles in a manner in opposition, each article having a side facing towards the garment and an adhesive facing towards the garment on said side facing the garment, the adhesive being protected by a release liner before use, the release liner having a first and a second surface; the articles having a longitudinal axis and said method comprising the steps of: providing a first and a second continuous stream of disposable absorbent articles in a side-by-side relationship; provide a continuous current of the release liner; applying adhesives on at least part of said side facing towards the garment of the absorbent articles; joining said first stream of absorbent articles; with said first surface of said stream of release liners; joining the second stream of absorbent articles to the second surface of the stream of the release liner; separating the combined streams such that at least one first article is attached to the first surface of the release liner, and at least one second article is attached to the second surface of the release liner. 2.- Procedure for making disposable absorbent articles in a manner in opposition, each article having a side that faces the garment, and an adhesive that gives towards the garment on the side facing the article of clothing, the adhesive protected by a release liner before use, the release liner having first and second surfaces, the articles having a longitudinal axis and said method comprising the steps of: providing first and second continuous streams of disposable absorbent articles in a side-by-side relationship; - providing a continuous current of the release liner; applying adhesives on at least part of the first and on and at least part of the second surface of the release liner; joining the first stream of absorbent articles to the first surface of the stream of the release liner; - joining the second stream of absorbent articles to the second surface of the stream of the release liner; separating the combined streams such that at least one first article is attached to the first surface of the release liner, and at least one second article is attached to the second surface of the release liner. 3. Process for producing disposable absorbent articles in an oppositional manner, each article having a side that faces towards the garment and an adhesive that gives towards the garment on the side facing the article of clothing, the adhesive protected by a release liner before use, the release liner having first and second surfaces; the articles having a longitudinal axis and the method comprising the steps of: providing first and second continuous streams of disposable absorbent articles in a side-by-side relationship; provide a continuous current of the release liner; - joining the first stream of absorbent articles to the first surface of the stream of the release liner; applying adhesives on at least part of the side facing the garment of the second continuous stream of disposable absorbent articles; - joining the second stream of absorbent articles to the second surface of the stream of the release liner; separating the combined streams such that at least one first article is attached to the first surface of the release liner, and at least one second article is attached to the second surface of the release liner. 4. Process for producing disposable absorbent articles in an oppositional manner, each article having a side facing towards the garment and an adhesive that gives towards the garment on said side facing the garment, the adhesive protected by a release liner before use, the release liner having a first and a second surface; the articles having a longitudinal axis and the method comprising the steps of: applying a first and a second continuous stream of disposable absorbent articles in a side-by-side relationship; provide a continuous stream of release liner; - applying adhesives on at least part of the side facing the garment of said first continuous stream of the disposable absorbent articles; joining the first stream of absorbent articles to the first surface of the release liner stream; - applying adhesives on at least part of the second surface of the release liner; joining the second stream of the absorbent articles to the second surface of the stream of the release liner; separating the combined streams such that at least one first article is attached to the second surface of the release liner, and at least one second article is attached to the second surface of the release liner. 5. Method according to any of the preceding claims, wherein the first and second continuous streams of disposable absorbent articles are part of a second continuous stream of pairs of disposable absorbent articles, which are attached to the release liner by bending said continuous current on itself around the release liner. 6. Method according to any of the preceding claims, wherein the step where the separation step is a die cut along the total periphery of said first and said second absorbent article. 7. Method according to any of the preceding claims, wherein the absorbent articles are joined in correspondence with the release liner. 8. Method of compliance with any of the preceding claims, wherein the articles are sanitary napkins or linings for panties. 9. Process according to any of the preceding claims, comprising the additional step of packaging the items in quantities of no more than two items per package.