GB2512049A

GB2512049A - Articles with composite side panels comprising lines of weakness and method for producing such articles

Info

Publication number: GB2512049A
Application number: GB201304863A
Authority: GB
Inventors: Christoph Schmitz
Original assignee: Concepts for Success C4S
Current assignee: Concepts for Success C4S
Priority date: 2013-03-18
Filing date: 2013-03-18
Publication date: 2014-09-24
Also published as: GB201304863D0

Abstract

An article, such as a disposable absorbent article worn around the lower torso, has side panels forming side portions 1118,1218 which are connected 1050 to a centre strip and have lines of weakness 2300 which are connected and joined when the article is in an unfolded pre-use configuration but may be separated, severed or disjoined prior to use. The lines of weakness may be or perfn pop perforation lines, a discontinuity in a material or a pattern of points or cutting lines with lower strength, by thinning, partial breakage, or intermittent slits or holes. Two overlapping side panels (2100,2200 figures 1B-D) connected together may extend from each side of the strip or a single panel (4100,5100 figure 2) may extend across the strip and have a second, overlapping panel (4200,5200) bonded (2410,2420) to it either side of the lines of weakness (4300,5300) . A method of manufacture is also disclosed.

Description

ARTICLES WITH COMPOSITE SIDE PANELS COMPRISING LINES OF

WEAKNESS AND METHOD FOR PRODUCING SUCH ARTICLES

Field of the invention

The present invention is an article, such as a disposable absorbent article, comprising side panels comprises web materials, which comprise a line of weakness allowing 1 0 predetermined disjoining and which are connected to each other and a method for forming such articlcs.

Background

Absorbent article, and in particular disposable absorbent articles are often manufactured 1 5 in a way that side panels are connected to a centre strip so as to allow to fit them around the waist of a wearer. Such articles have been described iii more detail in copending application W0201 1/064275.

It is also known, to design absorbent articles with a "per? n pop" feature, wherein lines of weakness are included; see e.g. EP0570980A1 or W02003/057102A2 describing pants style absorbent articles with a line of weakness arranged in the side panel or closure tape region.

However, there remains a need for allowing broader design flexibility with regard to thc arrangement of the side panels, in particular for side panels having a larger circumferential extension on the body.

Further, an issuc for the manufacturing of such articles remains in an unsatisfactory control of the applied side panels especially for high speed production processes.

Summary

The present invention is an article for being worn on the lower torso of a wearer, the article exhibiting a pre-use and an in-use configuration, which comprises a front region, a rear region and a crotch region there between, thcreby defining a longitudinal (x-) and width (y-) direction and a longitudinally extending centre line of the article; a centre strip extending from the front region through the crotch region to the rear region and exhibiting a first and a second longitudinally extending side margin; at least a first and a second article side panel comprising side panel web pieces;.

a first and a second leg hoop connected in a z-directionally overlying relationship to said centre strip at least in said crotch region and to said first and said second side panel wcb pieces, respectively.

In the in-use configuration of the article, the first and second article side panels extend laterally outwardly from the front and/or rear region(s) and are connected thereto, and at least one fn-st and one second article side panel comprises a portion of a first and a portion of a second side panel web piece.

In a pre-use configuration, the portions of the side panel web pieces are delimited by a line of weakness being positioned essentially parallel to or coinciding with the 1 0 longitudinal centre line; and the first and the second side panel web pieces are connected to each other along a first and a second side panel web pieces connecting lines adjacent to and opposite of the line of weakness.

Further, in the in-use configuration the line of weakness is disjoined.

In the pre-use configuration, each one portion of the side panel web pieces may be connected to the centre strip whilst the portion opposite of the line of weakness is not connected thereto. Also both portions of the first side panel web pieces may be connected to the centre strip, whilst none of the portions of the second side panel web piece are coimected to the centre strip. Optionally, the side panel web pieces may be folded along their longitudinal direction, and/or may comprise closure means. Preferably, the article side panels are connected to the centre strip along curvilinear centre strip connection lines, preferably by ultrasonic heat bonding.

The present invention is also a method for forming an article, wherein the article comprises a front waist region, a rear waist region and a crotch region there between, thereby defining a longitudinal (x-) and width (y-) article direction and a longitudinal centre line and a first and a second rear and/or a first and a second front article side panel connected to the centre strip in respective regions.

The method comprises the following steps: (a) Providing an essentially continuous centre strip web with its machine direction corresponding to the longitudinal direction of the article.

(b) Providing first side panel web pieces.

(c) Creating a line of weakness in the first side panel web pieces.

(d) Positioning the pieces of the first side panel web pieces in an overlying configuration with the centre strip web, such that the line of weakness is essentially parallel to the MD of the centre strip web, preferably aligned with the longitudinal centre line.

(e Connecting the centre strip web and the first side panel web pieces by essentially MD oriented centre strip connecting lines which lie opposite to each other relative to the line of weakness, whilst leaving the centre strip web and the first side panel web pieces essentially unconnected to each other there between such that a closed material composite is formed.

The method may thrthcr comprise the following steps: (f) Providing second side panel web pieces.

(g) Creating a line of weakness in the second side panel web pieces.

(h) Positioning the first and the second side panel web pieces such that their respective lines of weakncss are essentially parallel and adjacent to each other.

(i) Connecting the first and the second side panel web pieces along at least two connecting lines essentially parallel and on both sides adjacently to, preferably less than 5 cm laterally outwardly ot the lines of weakness.

Therein, step (e) is executed such that the closed material composite is formed by the centre strip material and the first and/or the second side panel web pieces.

Steps (c) and (g) may be executed simultaneously on both webs whilst these are in a juxtaposed position.

Further, in one alternative, step (e) may be executed such that only the first or the second side panel web pieces are connected to the centre strip web. Then the side panel web piece, which is unconnected to the centre strip web, may be positioncd between the centre strip web and the connected side panel web piece, optionally further comprising closure means adapted to connect the front and the rear region of the article during use, and/or it may comprise one or more longitudinal fold lines preferably at least one longitudinal fold line on each side of the line of weakness. In a second alternative, step (e) may be executed such that the first and the second side panel web pieces are connected to the centre strip web, wherein optionally both side panel web pieces comprise closure means adaptcd to connect the front and the rear region of the article during use.

For all alternatives, the process steps (b) to (i) may be executed for front and for rear side panels of the article, and! or such that at least two articles are formed cross-directionally parallel and simultaneously.

The creating of the line of weakness in steps (c) and (g) is preferably executed such that the forces for tearing the of weakness open is adapted to be executed by a user, preferably requiring tear forces of less than 60 N, more preferably less than 30 N, even more preferably less than 15 N, and most preferably less than 9 N, determined by the method as described herein.

Preferably, step (e) is executed such that the connecting is along a curvilinear centre strip connecting line or region, preferably by ultrasonic heat bonding.

Brief descriptioii of the Figures

Fig. I A and B show schematically a top view on an article as known from prior art and an article according to the present invention.

Fig. IC. and ID show schematically a cross-sectional view through an execution according to the present invention in its pre-use configuration as well as in an ill-use / ready for use configuration.

1 0 Fig. 2 A, B, and C depict schematically a fbrther execution of an article according to thc present invention with a top view and a front and a rear cross-sectional view.

Same numerals refer to the same elements or features.

Detailed description

1 5 In a first aspect, the present invention is an article for being worn on the lower torso of a wearer, such as a disposable absorbent article. An article according to the present invention may be based on othcr conventional designs but preferably is based on articles as described in the above referenced application W0201 1/064275, as can be seen in a top view in Fig. IA. Therein, the article is shown in a pre-use configuration with a centrc strip 1010 with a front (1012), rear (1018), and crotch (1015) portion, thcrcby defining a longitudinal (x-) and width (y-) article direction and a longitudinal centre line as well as a z-direction perpendicular to the x-and y-direetion. The front and rear portions have side portions, a first (1112) and a second (1212) fl-on! side portions (which may be a left and a right portion during use) and a corresponding first (1118) and a second (1218) rear portion. In this configuration, the side panels forming the side portions are overlying the centre strip 1010 and partiy themselves hence depicted with dashed lines. In an in-use configuration (not shown), the side panels extend laterally outwardly of the centre strip, as may be appropriate prior to donning, or even more just prior to closing the article on a wearer. The side panels are connected to the centre strip by connecting lines, here shown in the preferred execution of curvilinear centre strip connccting lines 1050. A flist and a second leg hoop 1400 are positioned so as to at least partially z-directionally overlie the centre strip in the crotch region as well as the side portions, and connected thereto by a curved connecting line 1450. Closure means (not shown in Fig. IA) may be connected to the front or rear side panel, such as -without limitation -tapes or patches with mechanical or adhesive connecting means.

It is important for the present invention that the article comprises in the side panel regions lines of weakness, which arc still connected and joincd as long as the article is in its pre-use configuration, i.e. also during manufacturing. This line of weakness is sometimes also referred to as a "perf'n pop" line, denoting that (luring manufacturing a perforation line is applied, which is "popped" open upon use.

In general terms, the line of wealuwss refers to a discontinuity linc in a material, often a web material such as a film, a non-woven or a composite thereof, which exhibits a lower strength than the surrounding regions or than the material prior to applying the discontinuity. This discontinuity may be introduced by the manufacturer of the article, 1 0 though it may ahtady be introduced by the manufacturer of the material, e.g. the web material.

The line of weakness is intended to be separated or severed or disjoined in a controlled manner such as prior to donning by a user, or at a later step in the manufacturing process.

After the opening, the line of weakness can be seen as the delimiting perimeters of the 1 5 separated materials. Prior to opening, a line of weakness is a pattern of points or lines or other shapes exhibiting lower strength than the surrounding material, as may be achieved by thinning of the material, or partial breakage of the material, or by introducing a separate kind of material exhibiting a lower strength, or actually no strength, such as in thc casc of pcrforations or slits. The pattern may be arrangcd curvilincarly or straight.

Thus, an article according to the present invention has an in-use configuration that is different from its pre-use configuration.

The "pre-use configuration" is typically established by the article manufacturer and comprises the line of weakness in its joined status. It may further be foldcd in a particular way so as to allow easy packing and shipping of the article. Fig. lB depicts schematically and exemplarily such au article according to the iuiveuition in a partly unfolded pre-use configuration. As for an article shown in Fig. IA, the article comprises centre strip 1010 with a front (1012), rear (1018), and crotch (1015) portion and leg hoops 1400. However, the side panels are configured differently, as can be seen in Fig. 1 C showing a cross-sectional view along line A-A in Fig. 13. An absorbent core 1700 as may suitably be used in case of a disposable absorbent article is shown to be enveloped between a topsheet 1600 and a backsheet 1800. A first (2100) and a second (2200) side panel web material or pieces thereof are positioned in an overlapping arrangement and the respective outward perimeter is essentially aligned with the longitudinally extending side margins 1500 of the centre strip and connected thereto by bond lines 1050. The opposite side margin of the side panel web or pieces, here shown with closure means 3010 and 3020, respectively, extend beyond the longitudinal centre line 1005 of the article but not into the connecting region of the respective opposite side panel web piece. Along this line, lines of weakness 2300 are applied to both the first and the second side panel web pieces. Just laterally outwardly of these lines of weakness, the two side panel web pieces are connected to each other by bond lines 2410 and 2420, which may also be executed as bond regions, respectively.

In order to arrive at the "in use configuration", the article may now be unfolded and the lines of weakness are irreversibly disjoined. The article may then be donned to a wearer, and closure tapes may be used to close the article around the waist and/or legs and/or to adjust the fit. As shown in 1D, the lines of weakness are opened (as indicated by 2300' and 2300'') whilst the connecting lines 2410 and 2420 remain unopened. Hence, the first (2510) and the second (2520) side panel of the article are now composed of two pieces, each one of the first and of the second side panel web pieces 2200 and 2300, connected by connecting lines 2410 and 2420, respectively.

1 5 Further executions of the present invention are depicted schematically in Fig. 2Awith cross-sectional views shown in 28 and 2C.

The principle basis for the description may be an article as depicted in Fig. 2A. In an execution shown for the front part 1012 of the article in connection with cross-sectional view B--B in Fig. 2C, a first side panel web piece 5100 is positioned such that both its longitudinally extending side margins 5500 correspond to the longitudinally extending side margins of the centre strip 1500 and are connected thereto. A second side panel web piece 5200, here shown with a first (5310) and a second (5320) closure means, is positioned between the backsheet 1600 an the first side panel web piece 5100, connected to the first side panel web piece 5100 by two connecting lines 5410 and 5420, with a line of weakness 5300 extending through both the first and the second side panel web piece.

The disjoining of the line of weakness will convert the shown pre-use configuration into the in-use configuration, with each of the article side panels comprising a piece of' the first and the second side panel web pieces.

Yet a farther execution is described for the rear part 1018 of the article in connection with cross-sectional view A-A in Fig. 2B. A first side panel web piece 4100 is positioned such that both its longitudinally extending side margins 4500 correspond to the longitudinally extending side margins of the centre strip 1500 and are connected thereto. A second side panel web piece 4200 is positioned between the backsheet 1600 and the first side panel web piece, connected to the first side panel web piece 4100 by two connecting lines 4410 and 4420, with a line of weakness 4300 extending through both the first and the second side panel web piece. As shown, the second side panel web piece is longitudinally folded twice, but even more folds, such as in a so called "leporello" fold can be made. The folded over parts of thc second side panel web piece should not extend across the longitudinal centre line. In order to convert this pre-use configuration, the lines of weakness are opened, and the folded parts of the second side panel web piece, now connected to the first side panel web piece are part of the article side panel.

Whilst these executions have been used to describe the principles of the present invention, they should not be seen to limit the various executions.

For example, various executions may be combined in one article, and in a preferred 1 0 embodiment and article comprised both executions shown in Fig. 2. Such an embodiment can provide articles with a relatively long rear article side panel to be combined with a relatively shorter side panel in the front such as may result upon particular arrangement of the closure means in.

In a particular aspect, the present invention relates to the forming or manufacturing of an 1 5 article, which comprises a front waist region, a rear waist region and a crotch region there between, thereby defining a longitudinal (x-) and width (y-) article direction and a longitudinal centre line and a first and a second rear and/or a first and a second front article side panel connected to the centre strip in respective regions. The manufacturing method comprises the following steps: (a) providing an essentially continuous centre strip web with its nmchine direction corresponding to the longitudinal direction of the article; (b) providing first side panel web pieces (e) creating a line of weakness in the first side panel web pieces; (d) positioning the first side panel web pieces in an overlying configuration with the centre strip web, such that the line of weakness is essentially parallel to the MD of the centre strip web, preferably aligned with the longitudinal centre line; (e) connecting the centre strip web and the first side panel web pieces by essentially MD oriented centre strip connecting lines which lie opposite to each other relative to the line of weakness, whilst leaving the centre strip web and the first side panel web pieces essentially unconnected to each other there between such that a closed material composite is formed.

In a preferred execution, the article comprises leg hoops, and for the introduction thereof the method may thrther comprise the steps (k) providing a first and a second leg hoop material; (1) positioning said first and said second leg hoop in an overlying relationship to said centre strip and said first side panel web pieces; (m) connecting said first and said second leg hoop material to said centre strip and said first sidc panel web pieces.

The method may further comprise the following steps: (0 providing second side panel web pieces / segment; (g) creating a line of weakness in the second side panel web pieces; (h) positioning the first and the second side panel web pieces such that their respective lines of weakness are essentially parallel and adjacent to each other; (i) connecting the first and the second side panel web pieces along at least two 1 0 connecting lines essentially parallel and on both sides adjacently to, preferably less than 5 cm laterally outwardly of, the lines of weakness; wherein further step (e) is executed such that the closed material composite is formed by the centre strip material and the first and/or the second side panel web pieces.

Therein, steps (c) and (g) may be exccutcd simultaneously on both webs whilst these arc in ajuxtaposed position, such hen the two webs are placed n each other.

In a first alternative execution of the method, step e) is executed such that only the first or the second side panel web pieces are connected to the centre strip web. Then, the side panel web piece, which is unconnected to the centre strip web, may be positioned between the centre strip web and the connected side panel wcb picce. Optionally, the side panel web pieces may thither comprise closure means adapted to connect the front and the rear region of the article during use, or one or more longitudinal fold lines preferably at least one longitudinal fold line on each side of the line of weakness.

In a second alternative execution of the method, step e) is executed such that the first and the second side panel web pieces are connected to the centre strip web, wherein optionally both side panel web pieces comprise closure means adapted to connect the front and the rear region of the article during use.

For any of the executions, the process steps b) to i) may be executed for front and for rear side panels of the article and / or such that at least two articles are fonned cross-directionally parallel and simultaneously.

The creating of the line of weakness in step g) is executed such that thc forces required to disjoining the line of weakness is adapted to be executed by a user.

The line of weakness should be sufficiently strong to ensure processing and further handling of the article without disjoining, but it should be sufficiently easy to disjoin it so as to allow users to readily do it. Considering the manufacturing process, the tear strength required for conventional high speed production lines may be as high as about 85 N for 162 mm of tested web width. In case of certain process precautions or process variants, the required tear strength may be significantly less, and can be less than 9 N or lower.

Considering the requirements for a user, the tear strength should be as low as possible, i.e. close to zero N, and preferably be less than 60 N, more preferably less than 30 N, even more preferably below 14 N. The test should be executed according to ISO 9073-3:1989/ ASTM D 5733-99 ("Tear Strength of Non-Woven Fabrics-Trapezoid Procedure") which is hereby incorporated herein by reference. The test inputs included a gauge length of 25 mm, a test speed of 300nini per minute, a load limit of 100 N and a break sensitivity of 95%. The test procedure should also be applied for other webs, such as films or film/non- 1 0 woven composites.

In a preferred embodiment, the connecting of the article side panels is along a curvilinear centre strip connecting line or region, preferably by ultrasonic welding or heat bonding.

When at least two articles arc manufactured simultaneously and parallel to each other, with their longitudinal centre lines oriented machine-directionally, this "MD multi-lane" process may also be described by comprising the following steps: (1) Providing an essentially continuous centre strip web comprising centre strip segments, each of which corresponds to a centre strip of the article and which arc machine-directionally and cross-directionally positioned adjacently to each other, each of the segments exhibiting a first and a second centre strip longitudinal demarcation line corresponding to the longitudinally extending side margins of the article and a longitudinally extending centre strip segment centre line aligned with the longitudinal centre line of the article.

(2) Providing one or more side panel webs essentially aligned in the process machine direction and comprising side panel segments for forming the article side panels, each of the side panel segments exhibiting a first and a second side panel segment demarcation line oriented essentially in the machine direction.

(3)Separating individual side panel pieces from the side panel webs along an essentially cross-directionally extending separation line, which niay be a straight or a curved line, corresponding to cross-directionally extending side panel segment demarcation lines.

(4) Positioning a first of the side panel web pieces such that its first longitudinally extending side panel segment demarcation line is essentially aligned with the first centre strip longitudinal demarcation line (5) Positioning a second of the side panel web pieces such that it overlaps with or overlies the first side panel web piece at least along a portion of the longitudinal centre line.

(6) Connecting the first side panel web piece to the second side panel web piece along at least two connecting lines essentially parallel and on both sides adjacently to, preferably less than 5 cm laterally outwardly of, the longitudinal centre line.

(7) Creating a line of weakness in the first and the second side panel web pieces along thc longitudinally extending centre piece segment centre line between the two connecting lines.

(8) Positioning the combined firs! and second side panel web pieces onto the centre strip web such that two longitudinally extending side panel segment demarcation lines of the first side panel web pieces essentially coincide with the centre piece longitudinal demarcation line.

1 0 (9) Connecting the combined side panel web pieces along two longitudinally extending side panel segment demarcation lines of the combined side panel web pieces to a longitudinal demarcation line of the centre strip.

(10) Optionally separating cross-directionally adjacent centre strip segments along longitudinal demarcation line of the centre strip, thereby also separating respective side paiel pieces.

Claims

Claims 1. A method for forming an article, said article compnsmg a front waist region, a rear waist region and a crotch region there between, thereby defining a longitudinal (x-) and width (y-) article direction and a longitudinal centre line and a first and a second rear and/or a first and a second front article side panel connected to said centre strip in respective regions, said method comprising the following steps of: (a) providing an essentially continuous centre strip web with its machine direction 1 0 corresponding to the longitudinal direction of the article; (b) providing first side panel web pieces (c) creating a line of weakness in said first side panel web pieces: (d) positioning said pieces of said first side panel web pieces in an overlaying configuration with said centre strip web, such that said line of weakness is essentially parallel to said MD of said centre strip web, preferably aligned with said longitudinal centre line; (e) connecting said centre strip web and said first side panel web pieces by essentially MD oriented centre strip connecting lines which lie opposite to each other relative to said line of weakness, whilst leaving said centre strip web and said first side panel web pieces essentially unconnected to each other there between such that a closed material composite is fonned.
2. A method according to claim 1, further comprising the following steps (k) providing a first and a second leg hoop material; (I) positioning said first and said second leg hoop in an overlying relationship to said centre strip and said first side panel web pieces; (m) connecting said first and said second leg hoop material to said centre strip and said first side panel web pieces.
3. A method according to claim 1 or 2, further comprising the following steps of: (f) providing second side panel web pieces; (g) creating a line of weakness in said second side panel web pieces; (h) positioning said first and said second side panel web pieces such that their respective lines of weakness are essentially parallel and adjacent to each other; (i) connecting said first and said second side panel web pieces along at least two connecting lines essentially parallel and on both sides adjacently to, preferably less than 5 cm laterally outwardly ot said lines of weakness; wherein ifirther step (c) is executed such that the closed material composite is formed by said centre strip material and said first aiidIor said second side panel web pieces.
4. A method according to claim 3, wherein said steps (c) and (g) are executed simultaneously on both webs whilst these are in a juxtaposed position.
5. A method according to any of the preceding claims, wherein step (e) is executed such 1 0 that only said first or said second side panel web pieces are connected to said eentrc strip web.
6. A method according to claim 5, wherein the side panel web piece, which is unconnected to said centre strip web is positioned between said centre strip web and 1 5 said connected side panel web piece, optionally further comprising closure means adapted to connect the front and the rear region of the article during use.
7. A method according to claim 6, wherein said side panel web piece, which is unconnected to said centre strip web comprises one or more longitudinal fold lines preferably at least one longitudinal fold line on each side of the line of weakness.
8. A method according to claim 3 or 4, wherein step (e) is executed such that said first and said second side panel web pieccs are connected to said centre strip web, wherein optionally both side panel web pieces comprise closure means adapted to connect the front and the rear region of the article during use.
9. A method according any of the preceding claims, wherein said process steps (b) to (i) are executed for front and for rear side panels of the article.
10. A method according to any any of the preceding claims which is executed such that at least two articles are formed cross-directionally parallel and simultaneously.
11. A method according to any of any of the preceding claims, wherein said creating of said line of wcakness in steps (e) and (g) is executed such that the forces for disjoining said line of weakness is adapted to be executed by a user, preferably tear forces of less than 60 N, more preferably less than 30 N, even more preferably less than 15 N, and most preferably less than 9 N, determined by the method as described herein.
12. A method according to any of the preceding claims, wherein step (e) is executed such that said connecting is along a curvilinear centre strip connecting line or region, preferably by ultrasonic heat bonding.
13, An article for being worn on the lower torso of a wearer, said article exhibiting a pre-use and an in-use configuration, said article comprising 1 0 -a front region, a rear region and a crotch region there between, thereby defining a longitudinal (x-) and width (y-) direction and a longitudinally extending centre line of the article: -a centre strip extending from the front region through the crotch region to the rear region and exhibiting a first and a second longitudinally extending side margin; -at least a first and a second article side panel comprising side panel web pieces; - -and a first and a second leg hoop connected in a z-directionally overlying relationship to said centre strip at least in said crotch region and to said first and said second side panel web pieces, respectively, wherein in the in-use configuration of the article said first and second article side panels extend laterally outwardly from said front and/or rear region(s) and are connected thereto, and at least one first and one second article side panel comprises a portion of a first and a portion of a second side panel web piece, and wherein in a pre-use configuration said portions of said side panel web pieces are delimited by a line of weakness being positioned essentially parallel to or coinciding with said longitudinal centre line, and said first and said second side panel web pieces are connected to each other along a first and a second side panel web pieces connecting lines adjacent to and opposite of said line of weakness: and wherein in said in-use configuration said line of weakness is disjoined.
14. An article according to claim 13, wherein in the pre-use configuration, each one portion of said side panel web pieces is connected to said centre strip whilst the portion opposite of the line of weakness is not connected thereto.
15. An article according to claim 13 or 14, wherein in the pre-use configuration, both portions of said first side panel web pieces are connected to said centre strip, whilst none of the portions of said second side panel web piece are connected to said centre strip.
16. An article according to any of claims 13 to 15, wherein said side panel web pieces arc folded along their longitudinal direction.
17. An article according to any of claims 13 to 16, wherein said side panel web pieces 1 0 comprise closure means.
18. An article according to any of claims 13 to 17, wherein said article side panels are connected to said centre strip along curvilinear centre strip connection lines, preferably by ultrasonic heat bonding.