EP1410999B1 - Reclosable flexible package - Google Patents

Abstract

The flexible packaging comprises a body having an external principal face formed by a flexible sheet (26A,26B). It comprises a re-fastening band (43) and an adhesive (44) reactivated by pressure interposed between the sheet external surface and the fastening band. The adherence of the adhesive to the surface of the band is greater than the adhesive force of the adhesive to the packaging external surface. The two opposite ends of the folded band are connected by a longitudinal weld (14)

Description

The present invention relates to a flexible package, of the type comprising a body having externally at least one main face formed at least partially by a flexible sheet.

It further relates to a method of manufacturing such a package.

Many food products, such as powdery products such as coffee and flour, or granulated products such as pasta and rice are packaged in flexible packages of the aforementioned type. These packages are formed from one or more welded sheets. They generally have at least one lower transverse weld formed at the base of the body, an upper transverse weld initially formed at the upper end of the body and a longitudinal weld. In order to take the products contained in the package, the upper weld is totally or partially broken or the upper end of the package is totally or partially detached. The open package is a pocket whose access is possible from the upper end which forms a neck defining an access passage inside the pocket.

After removal, rupture or partial cutting of the upper transverse weld, it is difficult to maintain the neck closed to prevent leakage of the remaining products contained in the pocket.

To keep closed such packages, it has been proposed to provide an adhesive tape attached to the body, one end of which is permanently sealed on the outside of the body of the package and the other end of which is adapted to be glued to the body. opposite side of the body of the package after the neck has been folded on itself now so the neck compressed between the body of the package. Such an adhesive tape has a nature different from that of the sheet and its implementation is delicate.

Also known metal blades reported at the end of the neck, these metal blades having on both sides plastically deformable extensions allowing after the neck has been wound on itself to fold the extensions of the blade of the share and other neck to keep it in its rolled position.

Retaining means of the wound portion of the neck to allow a reliable resealing of the package are relatively expensive to implement because they require to bring on the packaging of the external elements.

The document FR-A-2,823,722 describes a flexible package in which the reclosing strip is cut partially in the flexible sheet forming the package.

The document US-A-5,928,749 describes a flexible package in which a disjoint reclosing strip of the flexible sheet forming the package is covered with a transparent film.

The object of the invention is to propose a flexible packaging that can be closed easily and whose manufacturing cost is reduced.

For this purpose, the subject of the invention is a flexible package as defined in claim 1.

Particular embodiments of the package are defined in the dependent claims.

The invention also relates to a method according to claim 7.

• la figure 1 est une vue en perspective d'un emballage selon l'invention, avant ouverture ;
• la figure 2 est une vue en section transversale de l'emballage de la figure 1, prise suivant le plan π ;
• la figure 3 est une vue en perspective partielle de l'installation pour la fabrication de l'emballage des figures précédentes ;
• les figures 4, 5 et 6 sont des vues analogues à celle de la figure 1 illustrant des stades successifs de la refermeture de l'emballage ;
• les figures 7 et 8 sont des vues identiques à celle de la figure 1 de variantes de réalisation de l'emballage selon l'invention ; et
• la figure 9 est une vue analogue à celle de la figure 3 de l'installation pour la fabrication de l'emballage de la figure 8.

The invention will be better understood on reading the description which follows, given solely by way of example and with reference to the drawings in which:

• the figure 1 is a perspective view of a package according to the invention, before opening;
• the figure 2 is a cross-sectional view of the packaging of the figure 1 , taken along the plane π;
• the figure 3 is a partial perspective view of the plant for manufacturing the packaging of the preceding figures;
• the Figures 4, 5 and 6 are views similar to that of the figure 1 illustrating successive stages of the reclosing of the package;
• the Figures 7 and 8 are views identical to that of the figure 1 embodiments of the packaging according to the invention; and
• the figure 9 is a view similar to that of the figure 3 of the facility for the manufacture of the packaging of the figure 8 .

The flexible package 10 shown on the figure 1 is intended for example for the packaging of coffee powder, or any other powder or granular product, food or otherwise.

It comprises a flexible sheet 12 folded on itself longitudinally and secured in a longitudinal weld 14. The package is initially closed at its lower end by a transverse weld 16 and at its upper end by a transverse weld 18.

More specifically, in the embodiment shown, the flexible package 10 forms a pocket 20 to be open at its upper end. The pocket 20 comprises a body 22 constituting the vertical trunk of the pocket, this trunk being intended to contain the packaged products. The body 22 is extended towards the upper end of the body by a neck 24 generally free of product.

The pocket 20 has two opposite main faces 26 extending parallel to each other and two side faces 28 connecting the main faces 26 and extending parallel to each other.

The longitudinal weld 14 defines, on one of the main faces of the pocket, two adjacent faces 26A, 26B. These two sections are connected to one another according to the height of the package by the longitudinal weld 14.

At the lower end, the body is closed by a bottom 30 obtained by folding the sheet. The lower transverse weld 16 is applied against the bottom 30.

The lateral faces 28 have, at their upper end along the length of the neck 24, an internal fold forming a bellows enabling the two main faces 26 to be brought together in the region of the upper transverse weld 18.

As illustrated on the figure 2 , the longitudinal weld 14 is of flesh-flesh type, that is to say that it is made by fitting against each other opposite portions of surfaces of the sheet delimiting the inside of the package.

According to the invention, the packaging incorporates means for retaining a wound portion of the neck of the package after initial opening to allow a reliable reclosing thereof.

These retaining means of a wound portion of the neck comprise a reclosing strip 43 held against the outer surface of the sheet 12 by a pressure-reactive adhesive 44 also called repositionable adhesive.

The strip 43 is retained along the section 26A. Alternatively, it is retained against the pan 26B. More generally, the strip is retained against a main face 26.

The strip 43 extends along the entire height of the package from the upper weld 18 to the lower weld 16. It extends parallel to the longitudinal weld 14.

In particular, the strip 43 extends above the welded beads 18 and 16. To avoid a weld of the strip 43 and cords 16 and 18, a coating avoiding welding is interposed between the strip and the sheet 12 in the region welds 16, 18. This coating is especially useful at the upper weld 18 where the strip must be subsequently peeled off.

The strip 43 is made of the same material as that constituting the sheet 12. Thus, the sheet 43 has the same structural characteristics as the sheet 12, that is to say that its thickness is identical to that of the sheet 12 of the same as its composition. Indeed, and as will be detailed below, the band 43 and the sheet 12 are from the same initial band.

The adhesive 44 extends only in the median portion of the strip 43, considering the width thereof. Thus, the lateral margins of the strip 43 are devoid of adhesive.

The adhesive 44 and the facing surfaces of the panel 26A and the strip 43 are adapted so that the adhesion of the adhesive 44 to the strip 43 is greater than the adhesion of the adhesive 44 to the panel 26A.

For this purpose, a repellent coating is advantageously applied to the outer face of the sheet 12 in the region of the strip 43 to reduce the adhesion between the adhesive and the sheet. Similarly, a repellent coating is advantageously disposed on the main face 16 not having the longitudinal weld and forming the face on which is subsequently bonded the strip 43 after reclosing. This coating is disposed at the location where the strip 43 is glued.

The repositionable adhesive is constituted by: double-sided adhesive tape cold application, continuous; a hot application hot melt, which can be interrupted; or a cold adhesive coating, which can be interrupted.

For the manufacture of such a packaging, the installation illustrated on the figure 3 is implemented.

The packages are manufactured continuously from an initial strip 50 packaged in a roll 52.

The band 50 has a width greater than the width of the sheet 12 necessary for the realization of the package.

The band 50 circulates in a unit 54 allowing the application of an adhesive on a marginal portion 56 of the initial band.

The station 54 comprises a roll 58 for deflecting the band, for applying and for fixing a double-sided adhesive tape 62 on the marginal part 56. This double-sided adhesive tape 62 comes from a reel 64 placed on a reel. continued. Double-sided tape is a repositionable adhesive.

Alternatively, the unwinder and the ribbon are replaced by a hot melt hot melt head 60 of the marginal portion 56 with a repositionable adhesive.

According to another variant, the roll strip already comprises a repositionable adhesive range. This range consists of a water-based adhesive that is printed beforehand when printing the film.

Downstream from the station 54 is arranged a cutting station 66 capable of continuously separating the marginal portion 56 previously provided with the adhesive from the remainder of the initial web to form, on the one hand, a packaging tape denoted 68 and, on the other hand, a reclosure band denoted 70 in this figure.

The cutting station 66 comprises, for example, two rotary cutting discs 72 engaged through the initial web and rotated by a drive motor 74.

Downstream from the cutting station 66 is a station 76 for shifting the reclosing band 70 and bringing it into contact with the surface of the packaging strip 68.

This station 76 comprises, for example, a fixed roll 78 coated with a sliding material such as "Teflon" whose axis extends generally parallel to the plane of the packaging strip 68. The axis of the roll is offset angularly relative to the direction of advancement of the packaging strip 68. It is arranged tangentially to the plane of the packaging strip 68.

The reclosing band 70 is engaged around the roll 78, its adhesive-free side being in contact with the roll.

We understand that the installation of the figure 3 allows, from the initial band, to obtain, at the output of the gluing station 60, an initial band whose marginal portion 56 is provided with an adhesive. This marginal region is cut by the station 66 and separated from the packaging tape 68. The reclosing tape 70 is then offset by the roller 78 and applied against the surface of the packaging tape 68 with its glued portion applied against the surface 68. The reclosing strip 70 is disposed away from the edge noted 80 of the packaging tape 68.

Because the band 43 is derived from the same initial band as the sheet 12, the cut edges facing the strip 43 and the sheet 12 have complementary profiles.

The packaging strip 68 to which is secured the reclosing strip is then placed around a tubular shaper having a generally circular section. The sheet thus wound around the tubular shaper sees its two longitudinal edges close to each other, and applied to one another along the face of the sheet facing the shaper. The longitudinal weld 14 is then performed by clamping the longitudinal edges between two heated jaws or between an anvil and a jaw.

The manufacture of the packaging is completed as known per se by simultaneous realization of the upper and lower transverse welds of two consecutive packages and the separation of these two packages.

The packaging is used as illustrated Figures 4 to 6 .

On the figure 4 , the package is shown partially while a corner of the upper end of the neck 24 has been cut to ensure the partial rupture of the upper transverse weld 18 and thus to allow access to the inside of the pocket .

The first stage of the reclosing of the package is to move the upper portion of the strip 43 of the pan 26A on the side of the opening.

To do this, the user grasps the upper end of the strip 43 and pulls it down the package.

Due to the difference in adhesion of the adhesive 44 to the surface of the strip 43 and to the panel 26A, the adhesive is entrained with the strip 43, covering the middle portion of the exposed surface thereof.

The detached portion of the band, at least over most of the length of the neck 24 is a tab 90 still secured to the lower body of the package. The base 92 of the strip, constituting the portion still bound to the body of the package, is located substantially in the extreme filling region of the package.

To ensure the reclosing of the packaging, and as shown on the figure 5 , the neck 24 is folded on itself several times to form a winding 94. This winding is formed along the main face 26 of the package having the weld 14. During the folding of the neck, the glued tab 90 is kept away from the winding 94.

As illustrated on the figure 6 after the neck 24 of the package is folded to form the winding 94 to the portion of the bag still containing articles, the glued tab 90 is folded transversely over and around the winding 94, the free end of the tab 90 being bonded to the main face 26 of the package opposite the main face carrying the weld 14.

It will be understood that the winding 94 is kept wound by the action of the tab 90 bonded, on the one hand, around the winding and secured at each of its ends, the main faces of the package.

In this position, the package is reliably closed.

On the Figures 7 to 8 , there are shown alternative embodiments of a package according to the invention.

On the figure 7 there is shown a package formed from a single sheet whose longitudinal weld 14 is of the flesh-to-leather type, that is to say that it is made by fitting the opposite surfaces of the sheet delimiting the packaging.

Thus, only one of the faces 26B of a main face of the package extends outside the package.

On the figure 8 is illustrated an alternative embodiment of the embodiment of the figure 2 .

In this embodiment, the reclosing band denoted 103 consists of two superimposed strips 43 connected to one another. One of the strips 43 is secured by an adhesive to the outer surface of the sheet 12. The other strip 43 is bonded to the first by an additional adhesive interposed between the two strips.

In addition, and alternatively, the two strips 43 are connected to one another by welding in the region of the upper 18 and lower welds 16. These welds are performed simultaneously to the welds 18 and 16.

As illustrated on the figure 8 , the installation for the manufacture of the packaging sheet has the same elements as those for the installation of the figure 3 .

It further comprises a second cutting unit 66 'disposed symmetrically at the first station 66 and adapted to cut a reclosing strip on the other edge of the initial strip 50. A gluing station 100 for the second strip is disposed downstream of the second cutting station 66 '. This station is adapted to apply an adhesive ensuring the subsequent connection of the two strips 43.

A second shift station 76 'is arranged to bring the second band noted 70' above the first band noted 70. This second station comprises two rollers 78 ', 78 "defining an angle of 45 ° with the direction of advancement The first roller 78 'provides a 90 ° directional change of the web relative to the advancing direction of the main web, the second roller 78 "again providing 90 ° angular offset of the web. so that it comes to apply on the first band 70 already applied against the packaging tape 68. The two strips 70, 70 'are bonded when they come into contact.

Such an embodiment is particularly useful when the thickness of the packaging sheet is reduced. Indeed, the doubling of the thickness of the reclosing strip ensures a greater resistance thereof.

Whatever the embodiment described here, it is understood that the package can be closed reliably, the winding formed from the collar can not itself unfold. In addition, the reclosing of the packaging is guaranteed by means having a very low cost, this means can be manufactured simultaneously with the bag packaging products. Finally, the establishment of the retention means of the winding is relatively easy for the user.

The packaging is here formed continuously. However, alternatively, the packages are prefabricated and left open at one end. They are only closed and sealed at this end after filling.

Claims (8)

1. A flexible packaging (10) comprising a body (22) having on the outside at least one main face (26) formed at least partially by a flexible sheet (12), comprising a re-closing strip (43) detached from said flexible sheet (12) before opening of the packaging and an adhesive (44) which can be reactivated by pressure interposed between the outer surface of the flexible sheet (12) and the re-closing strip (43), the force of adhesion of the adhesive (44) to the surface of the re-closing strip (43) being greater than the force of adhesion of the adhesive (44) to the outer surface of the packaging sheet (12), the re-closing strip (43) and the packaging sheet (12) having identical structural characteristics and having originated from one and the same initial strip, the packaging having, at one end, at least one transverse welded seam (16, 18), characterised in that the packaging sheet (12) is covered on its outer surface, at least in a region in which the re-closing strip (43) straddles the transverse welded seam (16, 18), with a layer which avoids welding interposed between the packaging film (12) and the adhesive (44), which layer which avoids welding is adapted to avoid welding of the re-closing strip (43) on the surface of the packaging sheet (12).
2. A packaging according to Claim 1, characterised in that said flexible sheet is folded over on itself and the two opposing edges of the folded-over strip are joined by a longitudinal welded seam (14), the folded-over strip being initially blocked at both its ends (16, 18), and in that the re-closing strip (43) extends parallel to the longitudinal welded seam (14).
3. A packaging according to any one of the preceding claims, characterised in that the adhesive which can be reactivated by pressure is an adhesive selected from the group consisting of a hot melt, a cold adhesive and a double-sided adhesive tape.
4. A packaging according to any one of the preceding claims, characterised in that the packaging sheet (12) is covered on its outer surface, at least in the region of application of the adhesive (44), with a repellent layer interposed between the packaging sheet and the adhesive (44), which repellent layer is adapted to limit the adhesion of the adhesive (44) to the surface of the packaging sheet (12).
5. A packaging according to any one of the preceding claims, characterised in that the adhesive (44) extends only in the median region of the re-closing strip (43), the margins of the re-closing strip (43) being devoid of adhesive.
6. A packaging according to any one of the preceding claims, characterised in that the re-closing strip (103) comprises at least two superposed strips (43) which are connected together, at least locally, the two strips having identical structural characteristics to those of the packaging sheet (12).
7. A packaging process for manufacturing a packaging according to any one of the preceding claims, characterised in that it comprises the steps consisting of:

   - cutting off a marginal region of an initial strip to form a re-closing strip (70) and a packaging strip (68);

   - applying, against a surface of the packaging strip (68), the re-closing strip (70) with the interposition of an adhesive which can be reactivated by pressure, a layer which avoids welding being interposed between the packaging strip (68) and the adhesive (44) of the re-closing strip (70) at least in a region in which the re-closing strip (70) straddles the transverse welded seam (16, 18); and

   - forming said packaging by shaping a section of the packaging strip (68) on which the re-closing strip (70) is held.
8. A process according to Claim 7, characterised in that it comprises, before the cutting-off stage, a stage of application of the adhesive in a marginal region of the initial strip (50) which is intended to form the re-closing strip (70).

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