Patent Grant
10420680
The present invention relates to a method and equipment for the handling of web materials, such as essentially continuous webs of plastic films, textiles, non-wovens, or papers, or the like, and to the handling of discrete parts or portions of such webs, which are to be recombined with such webs at a machine-directionally offset positioning.
Web materials, such as films, papers, woven or nonwoven materials are broadly used and handled in the industry. Often such webs are trimmed such that holes or apertures are created, which are discarded, whilst other materials, are added to the web.
It is a well-known technology to apply relatively short pieces of a second material to a first web, when the second material is cut from an essentially endless supply and the pieces of the second material are positioned in a spaced arrangement on the first web.
In a first approach, the second material is provided as an essentially continuous material running at a direction perpendicular to the first web, and the cut pieces are positioned cross-directionally onto the first web, see e.g. EP0652175A1. In this method, for the moment of the combination of the web and the pieces, there should be no speed mismatch and thus there is a strong limitation with regard to the manufacturing speed, or other complex measures must be taken.
In a second approach, the second material is applied when running in essentially the same direction as the first material, using the “cut and space” principle. This method is also referred to as “cut and slip” method, as it requires the shorter material to be accelerated to the speed of the first web.
Yet a further approach is to avoid a speed mismatch by use of varying speed support, such as well-known server motor driven rolls.
It is also known to separate a web along a predominantly longitudinally extending line, such as a meandering line, to machine-directionally offset one portion versus the other, optionally reposition the web path of one of these portions such that the previously outward longitudinal side margins are now positioned towards each other and the separation line forms lateral margins, see e.g. WO2008/141658A1, EP0539032A1, EP0797970A2, EP0396050A2, WO1998/025767A1, or WO1006/031180A1.
However, there is still a need for a simple and reliable method for applying discrete pieces or portions of a web material to other portions of the same web, in particular, if this web is of low strength or has elastic properties.
In a first aspect, the present invention is a method for repositioning and recombining separated portions of a web material machine-directionally offset. The method comprises the steps of:
whereby in the method the separated portions are positioned machine-directionally offset relative to the predetermined regions from which they are separated.
When the at least partially separated portions are fully separated portions, the method may further comprise the steps of
Optionally, the fully separated portions may be cross-directionally offset relative to the predetermined regions.
When the at least partially separated portions are partially separated portions, step 5) may be executed such that
The method may further comprise the steps of
The method may further comprise the steps of
Preferably, at least two units selected from the group consisting of the transfer unit, the separation unit, the reorientation unit, the combination unit, and the connection unit are essentially unitary.
In another aspect, the present invention is a method for the manufacture of disposable absorbent articles, which comprises the method for repositioning and recombining separated portions of a web material machine-directionally offset, wherein the separated portions may be side panel pieces adapted to form a waist hoop during use.
In yet another aspect, the present invention is an equipment for the repositioning of portions of a web material machine-directionally offset to the web material from which they are separated. The equipment comprises
Therein, the separated portions path and the second web path exhibit an essentially different path length. Optionally, the equipment may further satisfy at least one of the conditions selected from the group consisting of
The equipment may further comprise one or more of elements selected from the group consisting of
Optionally, the equipment may further satisfy at least one of the conditions selected from the group consisting of
In all figures, same numerals denote identical or corresponding features.
“Comprise,” “comprising,” and “comprises” is an open-ended term that specifies the presence of what follows, e.g. a component, but does not preclude the presence of other features, elements, steps or components known in the art, or disclosed herein. Within the present context, the term “predominantly extending in one direction” means that a line, a cut, or a separation line has a projection onto this direction that is larger than its projection onto the direction perpendicular thereto.
In a first aspect, the present invention is a method for repositioning fully or at least partially separated portions of a continuous web material machine-directionally offset to the web material from which they are separated, and in a second aspect an apparatus for executing such a process.
The present invention is particularly suitable for being used in continuous production processes, and even more so when such processes are operated at high production speed, that may exceed 500 m/min.
The method according to the present invention is particularly useful for the manufacturing of hygiene articles, such as, but not limited to, disposable baby diapers, training pants, adult incontinence articles, feminine hygiene articles, disposable underwear and the like. “Disposable” is used herein to describe articles that are generally not intended to be laundered or otherwise restored, i.e., they are intended to be discarded after use and, preferably, to be recycled, composted or otherwise disposed of in an environmentally compatible manner. It should be noted, that disposable articles may be used several times, such as wearing disposable underwear over several days, or re-using disposable absorbent articles if these have not been loaded at the first use occasion. It should also be noted, that disposable articles may be washable, and may actually be washed for a limited number of wash-cycles, typically not more than ten wash cycles.
The term “web material” refers to an essentially endless material in one direction, i.e. the longitudinal extension, or the length, or the x-direction in Cartesian coordinates relative to the web material. Often, though not necessarily, the web materials will have a thickness dimension (i.e. the z-direction) which is significantly smaller than the longitudinal extension (i.e. in x-direction). The webs exhibit lateral side margins and often, though not necessarily, the width of web materials (the y-direction) will be significantly larger than the thickness, but less than the length. Often, though not necessarily, the thickness and the width of such materials is essentially constant along the length of the web. Such web materials may be without intending any limitation, cellulosic fibre materials, tissues, films, woven or non-woven materials and the like. Typically, though not necessarily, web materials are supplied from a web supply unit in roll form, or on spools, or in a folded state in boxes. The individual deliveries may then be spliced together to form the essentially endless structure. A web material travels through process steps or an equipment along a web path along the machine direction of the process step or equipment, which is typically aligned with the longitudinal extension or x-direction of the web. A web material may be composed of several sub-web materials, such as—without limitation—being a multilayer non-woven, coated tissue, non-woven/film laminate. Also, two or more sub-web materials may be positioned aligned next to each other along the machine direction. Such sub-webs may be of the same type, or be different, such as by differing in composition, thickness, basis weight, or physical, including mechanical or chemical treatment of the sub-web materials. A particular execution may be a web material comprising elastic and non-elastic sub-web materials in a side by side arrangement along the machine direction, whereby the sub-web materials may be combined to form the web material prior to or concurrently with process steps according to the present invention. Web materials may comprise other materials, such as added particles, hydrophilizing agents and the like.
The terms “separating”, “separated”, or related expressions, in particular “separated portions”, as well as the terms “cut”, “cutting”, offcut, or “cut-out” refer to the excising of portions from predetermined discrete regions of a web material to form separated portions. Such methods are and respective equipment is well-known in the art, such as when using die cutters, wherein cutting blades operate against an anvil, or water jet cutting, or laser cutting or the like and thus not limited to “cutting” in the narrow sense of a separation technology employing one or more blades or dies. At least initially and until a reorientation, the separated portions exhibit the same directionality as the web material, i.e. a machine or x-direction, a cross machine or y-direction and a thickness or z-direction. The separated portions may be executed as fully separated portions, for which a separation line circumscribes the portions, or as partially separated portions. In the latter case, the separation line is not a closed line, like a circle, but exhibits a first and a second end point. Within the present context, these endpoints are cross-directionally offset and the connection line between these endpoints extends essentially cross-directionally. Then, the partially separated portion may be lifted from the plane of the web and may be rotated along a y-directionally axis by being folded along the cross-directional connection or fold line.
Within the present context, the essentially continuous web material may be considered a sequence of individual web pieces. In the beginning of the process, such pieces may not be discernible and be delimited by invisible demarcation lines only, and sequentially following pieces may be physically separated further downstream, i.e. in an additional process step within or after the method according to the present invention. Typically, though not necessarily, sequentially following pieces have the same length.
Each of these pieces comprises at least one predetermined region, from which material is separated out by a separation unit. In one execution, parts of said separated out material may be discarded as trim, whilst one or more portions of said separated material are intended to be recombined in a combination unit with the web material at a machine-directionally offset position relative to the predetermined region from which they are removed. In another and often preferred execution, all of the separated material, i.e. all the separated portions or the offcut are recombined with the web material at a machine directionally offset position. In yet a further execution in the context of partially separated portions, the originally leading portion of the partially separated portion may become the trailing portion, when overlaying the web material after being rotated around a y-directional axis.
The term “combined” or “recombined” is intended to refer to any predetermined relative z-directional positioning of the separated portions and the web material to each other in a direct or indirect contact. For example, the separated portions may be directly placed on either side or surface of the web material, or there might by a further material positioned between them, for example a further web material or pieces thereof, or an adhesive layer, or the like.
Either of the fully or partially separated portions and the web material may undergo certain treatment steps before they are combined again, for example, they may be folded, or stretched, or cross-directionally displaced relative to each other, or treated with another material, such as an adhesive or glue.
The separated portions and the still continuous web, from which these are separated, travel preferably both at unchanged overall process speed—along different process paths before being combined again. The web material is delivered along a first part of the web path to the separation unit and along a second part of the web path from the separation unit to the combination unit The separated portions are delivered along a separated portions path from the separation unit to the combination unit. In case of the fully separated portions, these are transferred from the separation unit via a transfer unit to the combining unit, whilst the second part of the web path of the continuous web runs via a guide unit, such as a guide roll or rod, which is different and typically longer than the path of the separated portions via a transfer unit. In the case, that the second web path is longer than the separated pieces path, the separated portions will be positioned machine-directionally before the predetermined regions from which these were separated. In case of the partially separated portions, the leading part of the portion will be temporarily attached to the transfer unit and follows the separated portion path, whilst the trailing part of the partially connected portion is still connected to the web material along the connecting line, which extends essentially cross-directionally and then forms a folding line. Thusly, the partially separated portion is z-directionally pulled out of the plane of the web when the path of separated portion diverges from the second part of the web path.
Within the present context, the second web path and the separated portion paths start and end at the point of separation in the separation unit and the point of recombination in the combination unit, respectively.
In an optional and often preferred execution of the present invention, the separated portions may change their orientation along the separated portions path by an optional reorientation unit. In a first variant, this change in orientation of a fully separated portion may be a rotation around a z-directional axis, such that for a 180° rotation a leading margin of a separated portion becomes a trailing margin. Whilst the rotation may be at any angle of rotation, the 180° angle is preferred. Rotating web material pieces and the related equipment is well known in the art, such as described in US2014/0102851, to which express reference is made for the rotating equipment and process. For example, a transfer unit may comprise reorientation units such as support plates for the separated portions that are rotatably mounted around an axis, which may be z-directionally oriented or slightly angled thereto. Optionally the support plates may be equipped with holding means for affixing temporarily the separated portions on the support plates, such as vacuum suction. Optionally, the support plates may be translatorily moveable z-directionally.
Another way of achieving a change in orientation can be the flipping of the fully separated portions, such that longitudinally extending margins are changed and simultaneously a first x-y-extending surface of the separated portions that was e.g. formerly upwardly oriented becomes downwardly oriented after the flipping.
In case of partially separated portions, the reorientation is achieved by the rotation around a y-directional axis as described in the above.
In addition to machine-directional offsetting, and optionally reorienting the separated portions, the fully separated portions may also be cross-directionally offset compared to the continuous web material. This may be achieved by dislocating the web material cross-directionally in course of the second web path, as may be achieved by angled s-bars as being well known in the art. It may also be achieved concurrently with the reorientation of the separated portions, such as when the rotating axes for the support plates are not positioned centrally but laterally thereof.
It should be noted that the repositioning of the separated portions can be done such that they extend over two web material pieces, i.e. over a virtual demarcation line between these, and then may be separated into sub-portions by the downstream separation step of separating the web into individual pieces. Also, the repositioning can be such that separated regions are combined with a different web piece as they are separated from, such as can be achieved by extending the web path of the continuous web material further.
Typically, the separated portions or sub-portions are connected to the web material directly upon the combining or thereafter in a connecting unit, as may be integral with the combination unit, or which may be separate and positioned after the combination unit in the direction of the web path. Such a connecting can be achieved by any conventional means, such as application of adhesives prior to the combining, or preferably by melt fusion bonding, such as ultrasonic bonding. In other cases, separated portions may be first connected to another web material, and thereafter to the web material from which they were separated.
At least some of the process units for executing the present invention may optionally, and often preferably, be unified to form a single unit, for example, an anvil of the separation unit may function as the transfer unit, and/or the transfer unit may be a part of the combination unit.
The principles of the present invention are now further explained by referring to the figures, which should not be seen limiting in any way.
In
The fully separated portions 300 are then removed from the web material, which is now referred to as web material with separated portions removed 100′. This removal may be achieved by transferring the separated portions to a transfer unit 500, such as a transfer roll equipment with holding means, such as vacuum suction. It may also be achieved by removing the web 100′, such as by having it run over a guide unit 400, as may be a conventional guide roll or turning bar. In analogy to the web path, the series of the discrete separated portions are moving along a separated portions path, which in the execution as shown corresponds to the surface of the rotating transfer unit 500. An optional reorientation unit 550, shown in
In the combination unit 600, the web material with separated portions removed 100′ and the separated portions 300 are recombined. Reconnecting the separated portions and the web material after the recombination may be achieved in a separate connecting unit further downstream of the combining unit in the direction of the web path, or preferably in a connecting unit 700 integral with the combining unit 600.
As neither the web material with separated portions removed nor the separated portions have changed their speed, but the web material with separated portions removed 100′ has been running over a predetermined and well and easily adjustable web path which is different and—as shown exemplarily—longer than the path of the separated portions, the positioning of the separated portions relative to their original position, which is now a cut-out portion in the web, has changed.
In
It should be noted that for the purpose of easy explanation, the separated portions are described to be recombined with the web material essentially as they are, i.e. they are not treated or otherwise handled other than machine and/or cross-directionally displaced. Also, all separated and cut-out material is recombined, so in this exemplary presentation there is essentially no scrap generated.
In
A particular method for the manufacturing of such articles is described in copending application PCT/EP2014/069538 (unpublished), to which express reference is made for the subject matter of forming side panels and in particular side panel extensions from a further backsheet material. In
The further backsheet 1100 as a continuous web material is shown with a first and a second end margin, that may correspond to a front or rear end margin of a web material piece 1112, and 1118, respectively, when travelling along a machine direction at a web speed 120, that may form the corresponding margins of adjacent further backsheet pieces (not shown), as discussed in the above. Two separation lines 314 and 316 are shown with dash-dotted lines, extending predominantly in the MD direction of the further backsheet and—for the example shown—symmetric to the longitudinal centre line 1005 (dash-double dotted line). This line separates a laterally inward piece 320 and two laterally outwardly positioned symmetric continuous pieces, which may form a first and a second front side panel of the article 1212, 1213, a first and a second rear side panel 1218, 1217, and longitudinally positioned there between a first and a second leg hoop 1194, 1196, which are positioned in the centre or crotch region 1115 of an article.
According to the present invention, side panel extension pieces may now be cut as separated portions or sub-portions thereof from the laterally inward piece 320. To this end, the side panel extension pieces are separated each around their full perimeter. This may be executed on a vacuum supported anvil drum 230, against which a die cutting unit 220 operates and performs the separation, as shown in
Whilst the vacuum holds the sub-portions for forming the side panel extension pieces on the anvil drum, the remaining continuous part of the further backsheet material web 1110 is withdrawn from this drum towards a guide roll and back to the anvil drum, thereby creating a machine directional offset such that the rearwardly positioned sub-portions form front side panel extension pieces on a further backsheet piece, whilst the forwardly positioned sub-portions form rear side panel extension pieces of an adjacent, e.g. preceding further backsheet piece.
As shown in
In a particular execution, the sub-webs are selected such that a centre portion 1125 is a non-elastic web, whilst two laterally outwardly positioned sub-webs exhibit cross-directional elastic properties. Such an arrangement is particularly useful for an application in a closed pant diaper, as schematically depicted in a perspective view of an in-use configuration. Therein, a combined side panel—side panel extension composite 2100 is connected to a centrepiece material 2000, as may be the front right part in the total pant article, with numerals corresponding to
| Number | Date | Country | Kind |
|---|---|---|---|
| 1416135.0 | Dec 2014 | GB | national |
| 1503278.2 | Feb 2015 | GB | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2015/070780 | 9/11/2015 | WO | 00 |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2016/038170 | 3/17/2016 | WO | A |
| Number | Name | Date | Kind |
|---|---|---|---|
| 6544375 | Schmitz | Apr 2003 | B1 |
| 20140102851 | Papsdorf | Apr 2014 | A1 |
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| 396050 | Nov 1990 | EP |
| 539032 | Apr 1993 | EP |
| 652175 | Oct 1995 | EP |
| 797970 | Feb 1997 | EP |
| 1996024319 | Aug 1996 | WO |
| 1996031180 | Oct 1996 | WO |
| 1998025767 | Jun 1998 | WO |
| 2008141658 | Nov 2008 | WO |
| 2015036561 | Mar 2015 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 20170239100 A1 | Aug 2017 | US |
