Patent Application
20220400819
The present invention relates to rolls of an elongated material for manufacture of fastening tabs as well as to methods of manufacturing fastening tabs.
Fastening tabs are widely used in hygiene industry. One important application of such fastening tabs relates to the closure system of diapers. These fastening tabs comprise a substrate having a manufacturer's end typically including an adhesive for attaching a tab to a disposable article, e.g., to the outer side of a diaper's ear, and an opposite user's end which may be gripped by a user and attached to a landing zone of, e.g., the diaper. The user's end typically comprises a mechanical fastening material, such as a hook material for releasably attaching the fastening tab to e.g. a corresponding loop material provided in the landing zone, as well as a finger lift, an area adjacent to the outer edge of the user's end free of fastening material for facilitating the gripping and lifting of the user's end by the user. Such fastening tabs are typically provided in large rolls of an elongated endless material, from which individual tabs are cut. Such fastening tabs are often provided on so-called twin rolls in the form of a planetary roll. The elongated material of such a twin roll comprises, along the cross or width direction, two adjacent fastening tabs, which are separated from one another through a center line of the elongated material. In these twin rolls, the user's ends, typically comprising the fastening material and the narrow finger lift, are arranged in the center of the elongated material with the finger lift areas being adjacent to one another along the center line, while the manufacturer's ends are provided at the outer regions of the elongated material, where adhesive then is applied near but spaced apart (˜2-3 mm) from the edges. The adhesive is applied away from the edge of the manufacturer's end, because during processing the web typically shakes in the cross direction along its path thus necessitating the positioning of the adhesive applicator head inwardly away from the edge.
These twin rolls according to the prior art have various disadvantages. The cross dimension of the elongated material (˜90 mm) is much lower than the diameter of the roll (which may be up about 1 m) and since the thickest portion of the elongated material i.e., the mechanical fastening elements in the user's ends is provided towards the center of the elongated material with the low profile manufacturer's ends to the outer regions, these twin rolls exhibit roll instability. In addition, it has been observed that upon storage, dust and dirt particles may penetrate deep into the roll. Finally, due the gap between the edge and the adhesive in the manufacturer's end, after attaching the tab via the adhesive to the absorbent article the non-adherent part of the manufacturer's end protrudes from the final product like a flap and may create sharp edges or corners.
Surprisingly by providing a twin roll of an elongated material where the mechanical fastening elements are provided in the two outer longitudinal edge portions (each being at most 30% of the total width of the elongated material) and where on the same side at least the innermost central region (which for example may have a width up to 30% of the total width of the elongated material) of the central portion is free of said fastening elements so that such portion or at least a part of such portion thereof can be used to affix tab(s) obtained from such roll to absorbent article(s) (and thus accordingly the opposite side is free of adhesive), it is possible to provide a twin roll having improved roll stability and resistance to penetration of dirt and dust into the roll. In other words, by providing the user's ends with the fastening elements in the two outer edge regions at or close to the edges of the elongated material and the manufacturer's ends there between, the fastening elements, i.e. the thickest portions of the elongated material, are provided in the two outer edge portions at or close to the edges of the roll, thus facilitating roll stability and acting as a barrier helping to prevent or reduce ingress of dust and dirt particles into the roll.
Accordingly in a first aspect of the present invention there is provided a roll of an elongated material, the elongated material comprising first and second major surfaces, two longitudinal edge portions and a central portion provided in the width direction in between the two longitudinal edge portions, the width of each longitudinal edge portion being at most 30% of the total width of the elongated material, wherein each of the two longitudinal edge portions has fastening elements provided on at least a region of the first major surface, wherein the central portion comprises an innermost central region, the first major surface of the innermost central region being free of fastening elements, and wherein the second major surface is free of adhesive.
Due to the improved roll stability, the provision of twin rolls having longer roll lengths (and thus higher roll diameters) and/or more narrow cross-widths is advantageously possible. Furthermore by providing the user's ends with the fastening elements in the two outer edge regions at or close to the edges of the elongated material, it advantageously possible to provide, in addition to planetary rolls having higher stability, rolls where the elongated material is cross wound (cross wound rolls) and thereby provide wider rolls with longer roll lengths than that that can be achieved with a planetary roll of the same roll diameter.
In addition, by advantageously positioning the manufacturer's ends in the middle, the width of the manufacturer's end can be easily lengthened as needed and/or desired without immediately, detrimentally impacting roll stability. In this regard, it is to be appreciated that the use of a longer manufacturer's end and thus overall longer fastening tab in conjunction with a landing zone on e.g. a diaper or incontinence brief can be useful in providing a wider range of sizing.
As indicated above the width of the innermost central region in the central portion may be up to 30% of the total width of the elongated material, in particular ranging from about 7% to about 30% (inclusive) of the total width of the elongated material.
Preferably, the width of each longitudinal edge portion is at least 13% of the total width of the elongated material.
Each of the longitudinal edge portions may comprise an outermost edge region whose first major surface is free of fastening elements. Once a fastening tab has been cut from the roll of elongated material, such an outermost edge region provides a so-called finger lift to the user. The width of each of the outermost edge regions is preferably in the range between 3% and 10% (inclusive) of the total width of the elongated material. Preferably, the width of each of the edge regions is in the range between 3 mm and 12 mm (inclusive), more preferably between 5 mm and 9 mm (inclusive).
Preferably, each of the longitudinal edge portions comprises a fastening region with the fastening elements of the longitudinal edge portions being provided on the first major surface of each of said fastening regions. The width of each of the fastening regions is preferably in the range between 3% and 30% (inclusive), more preferably between 10% and 27% (inclusive) of the total width of the elongated material. Preferably, the width of each of the fastening regions is in the range between 10 mm and 30 mm (inclusive), more preferably between 13 mm and 25 mm (inclusive).
It is preferred that the first major surface in the entire central portion is free of fastening elements.
Preferably, the elongated material is a laminate comprising a carrier web extending over substantially the total width of the elongated material and a fastening material comprising a plurality of fastening elements. Preferably, each longitudinal edge portion is provided with at least one elongate strip of the fastening material. The at least one elongate strip of the fastening material in each longitudinal edge portion may be directly or indirectly affixed to the carrier web via, e.g., adhesive, ultrasonic welding, and/or hot-air welding or in-situ lamination (e.g. where the elongate strip of the fastening material is extruded directly onto the carrier). The carrier of the laminate preferably comprises a non-woven. In addition, or alternatively, the fastening elements may comprise male fastening elements, which are preferably selected from the group consisting of hook fasteners, mushroom-shaped fasteners, stem-shaped fasteners, cup-shaped fasteners, T-shaped fasteners and mixtures thereof.
Twin rolls described herein are particular suited for in line processing towards affixing tabs onto absorbent articles or precursor materials for absorbent articles. Moreover while the first major surface of the innermost central region of the central portion of the rolled elongated material may be provided with adhesive, it is favorable to provide rolls wherein the first major surface of the innermost central region of the central portion is free of adhesive. This is advantageous in that such embodiments would not require a polycoat, and more particularly the means used for affixing the manufacturer's end can be selected as desired and/or needed at the time of the manufacture fastening tabs and their attachment to absorbent articles or precursor materials. It is to be appreciated that the first major surface of the central portion outside the innermost central region, in particular just adjacent to the two longitudinal edge portions, may include adhesive to provide for fastening tabs including a so-called “anti-flagging feature”.
Another aspect of the present invention is a method of manufacturing fastening tabs, the method comprising the following steps:
Due to the favorable placement of the user's ends with the fastening elements in the two outer longitudinal portions of the roll, after slitting and cutting the pair of tabs generated are in correct orientation to one another (e.g. right-hand tab on the right and the left-hand one on the left) for attachment to an absorbent article such as a diaper or an incontinence brief. With prior art twin rolls with the user's ends in the middle, after slitting and cutting, the generated pair of tabs need to be either flipped or rotated to bring them in the right orientation to one another for attachment to an absorbent article such as a diaper or an incontinence brief. Accordingly twin rolls and such methods described herein are also advantageous in that in-line-handling is easier.
Methods described herein preferably comprise the step of affixing at least one of the fastening tabs at its manufacturer's end to an absorbent article or to an absorbent article precursor material. The step of affixing may comprise one or a combination of ultrasound welding, hot-air welding and adhesive bonding. The step of affixing is preferably performed essentially at the same time or after the step of cutting each of the two elongated strips in the cross direction.
Preferably, the method comprises the step of applying an adhesive onto the first major surface of at least a part of the innermost central region of the central portion between unwinding and slitting the elongated material along its length through the innermost central region of the central portion and cutting each of the two elongated strips in the cross direction. Adhesive may be applied to the entire innermost central region or just a part (e.g. a major part) of the innermost central region. For those embodiments where adhesive applied only to a part of the innermost central region, desirably the adhesive is applied such that the step of slitting the elongated material along its length through the innermost central region of the central portion comprises slitting through the adhesive provided on the first major surface of the innermost central region. In this manner, each of the two sections of the central portion obtained after slitting has adhesive in the region along and adjacent to the cut edge. The method may further comprise the step of affixing at least one of the fastening tabs at its manufacturer's end to an absorbent article or to an absorbent article precursor material using the adhesive applied onto the first major surface of the innermost central region of the central portion. Preferably, the step of affixing is performed essentially at the same time or after the step of cutting each of the two elongated strips in the cross direction.
In those embodiments where adhesive is applied onto the first major surface of the innermost central region of the central portion and the elongated material is slit along its length through said applied adhesive, the respective portion of the manufacturer's end of the final fastening tab is fully covered with adhesive all the way to its cut edge. Thus, the manufacturer's end of the final fastening tab will nicely adhere to the absorbent article or the absorbent article precursor without any loose edges or flaps protruding from the absorbent article or the absorbent article precursor material.
Further preferred features are illustrated with reference to preferred embodiments which are shown in the following Figures, which show:
Referring to
Elongate strips of the fastening material may be directly or indirectly attached via adhesive, ultrasonic welding, and/or hot air welding. In addition it will be appreciated that fastening elements may also be provided in different patterns. For example each of the fastening regions may be provided with two or more (e.g. four) separate elongate strips of fastening material, each running along the length of the elongated material so that the resulting tabs include two or more patches of fastening elements with areas free of fastening elements in between the patches. Alternatively each of the fastening regions may be provided with at least one elongate strip of fastening material that is provided in the form of a reticulated mechanical fastener comprising multiple strands of fastening materials attached and/or integral to each other at bridging regions of fastening material. Examples of such a reticulated mechanical fastener are described in detail in WO 2012/112768 A1. Specific reference is made to this document, which is incorporated by reference herein in its entirety, in particular with regard to the structure of such reticulated mechanical fasteners and the manufacturing thereof.
This is best understood by reference to
The fastening elements may comprise male fastening elements which are, e.g., selected from the group consisting of hook fasteners, mushroom-shaped fasteners, stem-shaped fasteners, cup-shaped fasteners, T-shaped fasteners and mixtures thereof.
Carrier webs may be single-layered or multi-layered. They may comprise a film, a nonwoven, a textile (e.g. woven or knitted), a foamed material or combinations thereof, e.g. in the form a laminate (such as multilayer film laminate, multilayer nonwoven laminate or a film-nonwoven laminate). The layer(s) of carrier webs may made of various substances such as, for example, polypropylene, polyvinylchloride, polyethylene terephthalate, polyethylene, polyolefin copolymers or blends of polyolefins such as, for example, a blend of polypropylene, low density polyethylene and/or linear low density polyethylene. Carrier webs are desirably between 30 microns and 500 microns in thickness, and more desirably between 40 and 150 microns.
Returning to
As mentioned above in favorable embodiments, the innermost central region is free of adhesive. In addition while it may be desirable that the first major surface of the entire central portion is free of fastening elements, the first major surface of the central portion in regions outside the innermost central region, in particular just adjacent to the two longitudinal edge portions, may include adhesive for example to provide for fastening tabs including a so-called “anti-flagging feature”. This is best understood by reference to the exemplary embodiment shown in
Returning to the exemplary embodiment shown in
As mentioned above, the roll may also favorably be provided in the form of a cross wound roll.
It is to be mentioned that although not as favorable as the exemplary method shown in
It will be appreciated that the fastening tabs may be attached to absorbent articles per se or to alternative absorbent article precursor materials. In regard to the latter, for example, fastening tabs 14 may be instead, affixed to an ear web, said ear web may, in turn, be affixed to a diaper or incontinence brief precursor web.
The fastening tabs may also be affixed to the absorbent articles or absorbent article precursor materials by other techniques such as ultrasound welding, hot-air welding or the like. In such cases, one would dispense with the step of applying adhesive onto the first major surface of the elongated material e.g. as shown in
| Number | Date | Country | Kind |
|---|---|---|---|
| 14168822.6 | May 2014 | EP | regional |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 15312145 | Nov 2016 | US |
| Child | 17822862 | US |
