EP0517566B1 - Opening and closing device for thin film flexible package - Google Patents

Abstract

Closing and opening device for a thin-film packaging packet or bag in which the free edges of the envelope forming the packet or bag are brought together in order to form a bag head, and are then folded down or folded over. The non-heat-welded fold or folds (p) of the head of the packet or bag (S) are held by a label (20) affixed to the packet or bag (S') so as to straddle the said fold or folds (p), the face of the label (20) in contact with the bag (S') being equipped with a permanent adhesive which is absent or is masked in a zone where a pre-cut-out tab (32), intended to separate the label into two distinct portions, is provided, the said tab being integral with the rest of the label as long as the packet or bag (S') has not been opened for the first time. <IMAGE>

Description

The invention relates to a device for closing and opening a sachet or thin film packaging package.

Sachets or packets in sheet or thin film, such as a polypropylene film a few tens of microns thick, which already enclose food products, especially in the grocery sector, such as pasta, semolina, etc ... After making packages or sachets from a tube or reel of film and filling with product to be packaged, said packages or sachets are closed at their end distant from the bottom either using with a metal clip (to constitute packages of the "confectioner" type), either by folding the free edges of the sachet according to two or three heat-sealed folds (to form sachets with "front folds" or "back folds" or of the type "baker"), the folds then being generally held on the head of the sachet by affixing an adhesive tape see, for example, EP-A-0 388 310 where the constituent material of the packaging is a complex material, the part of which intended to constitute the i The inside of the package is made of a heat-sealable material. The opening of sachets of the "confectioner" type, -including for an ill-intentioned purpose-, then new closing using the metal clip can be carried out without any apparent trace remaining, with a consequence lack of guarantee as to the absence of fraudulent manipulation of the package or bag and its contents, while the opening of a bag with heat-sealed folds is frequently accompanied by a tear in the bag, made of "stringing" material, so that the contents of the package or sachet may escape and the container itself cannot be easily closed after first opening.

Also known from US-A-3,295,744 is a sachet in which, in order to avoid any leakage of the pulverulent product contained in the sachet, it is planned to form on the head of the latter a large number of folds closed using two separate adhesive strips, which increases the cost of implementation considerably.

The problem therefore arises of providing a device for closing a thin film package or sachet which overcomes the drawbacks which have just been mentioned, on the one hand, which does not significantly affect the cost of packaging, on the other hand and which, finally, is simple to use and does not require the transformation of the existing packaging lines of the factories for packaging the packaged products.

This problem is solved, according to the invention, using a closing and opening device for a package or sachet of thin film packaging in which the free edges of the envelope constituting the package or sachet are brought together. to form a sachet head, then folded or folded, the non-heat-sealed fold (s) of the head of the packet or sachet being held by an adhesive label affixed to the packet or sachet so as to overlap the said (s) fold (s), characterized in that the face of the label in contact with the sachet is provided with a permanent adhesive which is masked or does not exist in an area where a pre-cut tab intended for separate the label into two separate sections, said tab being integral with the rest of the label as long as the package or sachet has not been opened for the first time and being positioned on the head of the sachet or package so as to prevail noticeably paral along the free edge of the fold (s) of said head, and in that the label is attached to the head of the package or sachet so that said free edge is overlapped by said area where the permanent adhesive is masked or does not exist.

To allow the bag to be closed easily after its first opening, one embodiment provides that the area deprived of permanent adhesive is provided with a weak, non-permanent, pressure-sensitive adhesive, which is initially, that is, as long as the package or sachet has not been opened for the first time, coated with a protective film.

In such an embodiment, too, and when the area deprived of permanent adhesive is lined with a pressure-sensitive adhesive initially coated with a protective film, the invention provides for pre-cutting said film substantially in line with the tab to provide a gripping tab for said film so that after a first opening of the package or sachet and after the protective film has been removed, the area of the label topped with pressure-sensitive adhesive allows maintain said zone in contact with the package to close it, while not making any significant effort against new openings.

In one embodiment, the label has a substantially trapezoidal contour with large edges substantially perpendicular to the free edge of the fold (s) of the bag head and the pre-cut tongue, -which has a gripping end- , is limited by lines of through perforations each ruling between said large edges of the label.

In another preferred embodiment, the invention provides for masking the permanent adhesive in the area where the pre-cut tongue prevails with the aid of a "cover", for example made of silicone paper, which can be easily removed after the pre-cut tab has has been torn off so that, after a first opening of the package or sachet, it can be closed with the adhesive thus made operational in said area.

In this embodiment, also, the visible face of the label is lined with a plastic film which contributes to the solidity of the assembly as long as the package has not been opened, such an embodiment being used particularly advantageous for sachets containing food products such as pasta or the like and which are of a somewhat fluctuating shape depending on the filling, compaction of the content, etc.

The device according to the invention finds application for the various types of usual packaging for thin film sachets or packages, whether they are with single flap, double front fold, double rear fold, or with "baker" type closure. It makes it possible to dispense with the heat-sealing operation of the free edges of the sachet head, while offering a simple and safe means of checking the integrity of the sachet or package which it equips, which also keeps, its usual appearance, generally parallelepiped.

• la figure 1 illustre, schématiquement, un sachet ou paquet d'emballage connu ;
• la figure 2 est une vue en plan, à plus grande échelle du recto d'une étiquette d'un dispositif selon l'invention ;
• la figure 3 est une vue analogue à celle de la figure 2 mais pour le verso de l'étiquette et avec arrachement partiel ;
• la figure 4 est une vue semblable à celle de la figure 1 pour un paquet ou sachet muni d'un dispositif selon l'invention ;
• la figure 5 est une vue analogue à celle de la figure 2, mais pour une variante de réalisation ;
• la figure 6 est une vue analogue à celle de la figure 3, mais pour cette variante de réalisation ;
• la figure 7 est une vue analogue à celle de la figure 4 pour cette même variante de réalisation ;
• la figure 8 est une vue en coupe selon la ligne 8-8 de la figure 5.

The invention will be better understood from the following description, given by way of example and with reference to the appended drawing in which:

• Figure 1 schematically illustrates a known sachet or packaging package;
• Figure 2 is a plan view, on a larger scale of the front of a label of a device according to the invention;
• Figure 3 is a view similar to that of Figure 2 but for the back of the label and with partial cutaway;
• Figure 4 is a view similar to that of Figure 1 for a package or sachet provided with a device according to the invention;
• Figure 5 is a view similar to that of Figure 2, but for an alternative embodiment;
• Figure 6 is a view similar to that of Figure 3, but for this alternative embodiment;
• Figure 7 is a view similar to that of Figure 4 for the same alternative embodiment;
• FIG. 8 is a sectional view along line 8-8 of FIG. 5.

As shown in Figure 1, a package or sachet of thin film packaging, S, for example but without this indication having any limiting nature whatsoever, a polypropylene film whose thickness can be of the order of some tens of microns, is shaped according to a generally parallelepiped volume. It includes a bottom with a quadrangular outline from which stand four lateral faces like those visible in 10 and 11, the end parts of said faces opposite the bottom forming the neck or head 12 of the bag after they have been brought together. others by their free edge, heat-sealed, then folded or folded in a double front fold, a double back fold or a "baker's" type closure, the folds being held by a tongue 15 of adhesive tape applied, for example, to the lateral face 10 and top face 16 of the package.

The heat sealing operation of the free edges of the head of the package is an operation which requires relatively complex equipment, in particular if the rate of the packaging lines which can be of the order of eighty packages per minute must be constantly maintained. - on the one hand, while, on the other hand, the opening of the package or sachet in line with the line of heat sealing is sometimes inconvenient and / or is frequently accompanied by a tear, given the "stringy" nature of the material of the package or sachet, so that the content of the latter can spread, or else, once opened, the package or sachet cannot be easily closed, which can be a nuisance for the user.

To overcome these drawbacks, the invention proposes not to heat seal the free edges of the head of the packet or bag and to ensure its closure using a label, 20, FIGS. 2 and 3, intended to be attached. by gluing on the fold (s) p of the package or sachet S ′. The label 20, with a generally trapezoidal general outline with large edges 21, 22 and small edges 23 and 24, is pre-cut to provide a tongue 32, at the grip end 33 slightly protruding from the edge 21-, integral with the label 20 as long as the package has not been opened for the first time and which is limited by lines of through perforations 27 and 28 extending between the edges 21 and 22 parallel to the edges 23 and 24. The lines 27, 28 define two sections 29 and 30 of unequal dimensions, each with a substantially trapezoidal outline limited, respectively, by the edges 21, 22, 23 and the line of perforations 27, on the one hand, and by the edges 21, 22, 24 and the line of perforations 28, on the other hand.

According to the invention, the face of the label 20 intended to come into contact with the package or bag S ′ is provided with a permanent adhesive on the back of the section 30 and on the back of a part of the section 29, as shown by the dotted lines in FIG. 3-, while an area 31, bounded by the edges 21 and 22, the line of perforations 28 and a side 34 substantially parallel to the line 28 in the section 29, is either completely destitute any permanent adhesive or glue or, in a preferred variant, provided with a weak adhesive of the type of those sensitive to pressure, -as shown by hatching 37-, said weak adhesive being initially coated with a protective film 38 which prevails between the side 34 and the line of perforations 28 and therefore in line with the tongue 32.

In the embodiment described and shown the film 38 is pre-cut along a line 39 extending between the edges 21 and 22 and substantially in line with the tongue 32 to limit a portion of relatively large extent between the side 34, the edges 21 and 22 and said line 39 and a band portion 40 of smaller extent limited by edges 21 and 22, line 39 and an edge 41 substantially superimposed on the line of perforations 28.

For its use, the label 20 is placed on the fold (s) p of the packet S ′, FIG. 4, so that the side 34 is substantially parallel to the free edge a of the fold (s) p of the bag head and, in any event, so that practically no part coated with permanent adhesive of the label 20 overlaps the free edge a or folds (s) p . The bag S ′, thus closed in a simple and safe manner without the need to use heat sealing of the free edges of the head, is equipped with a means of checking its integrity since, for a first access inside the bag, the tongue 32 must be torn along the lines of perforations 27 and 28 and that such a tear obviously indicates an opening which it is not possible to conceal thereafter.

The folds p can, on the other hand, be formed again after a first opening of the bag and, after the protective film 38 has been removed, the pressure-sensitive adhesive added to the area 31 allows to re-apply said zone on the package or sachet to close it.

The first opening is made easy by the presence of the perforation lines 27 and 28 for tearing the tongue 32 whose gripping is facilitated by the presence of the tab 33, while the separation of the protective film 38 from the adhesive pressure sensitive is facilitated by the presence of the slight projection existing, after tearing off the tongue 32, between the line 28 and the edge 39 of said film.

Reference is now made to FIGS. 5 to 8 relating to another embodiment. In it the label 40 is generally rectangular in outline with large longitudinal edges 41 and 42 and transverse edges 43 and 44. A tongue 45, pre-cut, similar to the tongue 32 of the previous embodiment, prevails between edges 41 and 42, its gripping end 46 projecting from edge 42. It is limited by lines of perforations 47 and 48 which pass through the actual backing paper of the label 49, FIG. 8, which may have a grammage of the order of 90 g / m² and a protective film 50, for example a silicone paper with a grammage of about 60-70 g / m² and which is intended to mask an area 51, corresponding to the area 31 of the embodiment according to FIGS. 1 to 4, but which, unlike this embodiment, is also coated with the same permanent adhesive as that which decorates the entire back of the label 40.

As clearly visible in FIG. 6, the area 51 reigns between an edge 52 relatively distant from the line of perforations 47 and an edge 53 relatively close to the line of perforations 48, said area being further limited by edges directed longitudinally 56 and 57 very slightly distant from the edges 41 and 42 of the label thus limiting small margins 58 and 59.

To allow easy handling of the label and its implementation in packaging machines, the entire back of the label is initially coated with the protective film of silicone paper 50. To make the label operational, said film, -which is pre-cut to the right of the edges 52, 53, 56 and 57 as well as along two oblique lines 54, 55 extending from the line of perforations 47-, is removed from the label by peeling, which, owing to the presence of the small margins 58 and 59, can be carried out in a single piece from one end of the label so as to then leave visible the zones marked with dotted lines which prevail between the edges 44 and 52, on the one hand and 53 and 43, on the other. The label is then placed on the fold (s) p of the packet S˝, FIG. 7, so that the side 43 is substantially parallel to the free edge a of the fold (s) p of the head of sachet and, in any event, so that the part 51 of the protective film overlaps the free edge has fold (s) p .

After first opening of the sachet, which is obtained by tearing off the tab 45, the part of protective film 50 which remained on the back of the label can be easily removed by its prevailing edge between the sides 54 and 55 to reapply the permanent adhesive then visible on one side of the bag after part of the contents thereof have been removed and the folds have been reformed.

It is further provided, in the embodiment which has just been described, and to increase the resistance of the label, to provide the front thereof with a thin transparent laminated film 60, Figure 8, for example polyester a thickness of about 20 to 25 microns, which is also perforated in line with lines 47 and 48 like sheet 49 and protective film 50.

A device according to the invention can be easily implemented without difficulty on automatic machines, thus making it possible to maintain the rates of the packaging lines, or even to improve them, insofar as the usual heat-sealing operation of the folds of the bag head is no longer required.

It also makes it possible to associate directly with the package or sachet which it equips, -for example using a bar code printed on its recto, as shown schematically in Figure 2, price information, date of expiration, etc ...

Claims (9)

1. Closure and opening device for a packaging pack or sachet (S', S'') made of thin film, in which the free edges of the enclosure of which the pack or sachet consists are brought closer together to form a sachet head and are then turned down or folded back, the non-welded fold(s) (p) of the head of the pack or sachet being kept in position by an adhesive label (20, 40) affixed to the pack or sachet so as to straddle the said fold(s), characterized in that the face of the label (20, 40) in contact with the sachet (S', S'') is provided with a permanent adhesive which is masked or which does not exist in a region (31, 51) where a precut tab (32, 45) is arranged, intended to separate the label into two separate sections, the said tab (32, 45) being integrally attached to the remainder of the label so long as the pack or sachet has not been opened for the first time and being positioned on the head of the sachet or pack so as to extend substantially parallel to the free edge (a) of the fold(s) (p) of the said head, and in that the label is added onto the head of the pack or sachet so that the said free edge (a) is straddled by the said region (31, 51) where the permanent adhesive is masked or does not exist.
2. Device according to Claim 1, characterized in that the region (31) devoid of permanent adhesive is provided with a weak, pressure-sensitive adhesive (37) which is initially - that is to say so long as the pack or sachet (S') has not been opened for the first time - coated with a protective film (38).
3. Device according to Claim 1, characterized in that the label (20) has a substantially trapezoidal outline with large-sized sides (21, 22) which are substantially perpendicular to the free edge (a) or to the fold(s) (p) of the head of the sachet (S') and in that the precut tab (32) - which comprises an end for grasping (33) - is bounded by lines of perforations (27, 28) each extending between the large-sized edges (21, 22) of the label (20).
4. Device according to Claim 2, characterized in that the film (38) for protecting the pressure-sensitive adhesive (37) is precut substantially in line with the tab (32) to provide a flap for grasping the said film after the said tab has been separated from the remainder of the label (20).
5. Device according to Claim 1, characterized in that, in the region (51) where the precut tab (45) extends, the permanent adhesive is masked with the aid of a cover made of silicone-treated paper or the like.
6. Device according to Claim 5, characterized in that the said cover is precut out of a film (50) which initially covers the whole of the reverse side of the label (40) before being used.
7. Device according to Claim 5 or 6, characterized in that the visible face of the label is covered with a plastic film (60) which contributes to the robustness of the whole so long as the pack (S'') has not been opened.
8. Adhesive label (20, 40) capable of forming part of the constitution of a closure and opening device according to any one of the preceding claims, the face of the label (20, 40) which is to come into contact with the sachet (S', S'') being provided with a permanent adhesive which is masked or which does not exist in a region (31, 51) where a precut tab (32, 45) is arranged, intended to separate the label into two separate sections, the said tab (32, 45) being integrally attached to the remainder of the label so long as the pack or sachet has not been opened for the first time.
9. Pack or sachet (S', S'') comprising a closure and opening device according to any one of Claims 1 to 7 or a label according to Claim 8.

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