EP3708510B1 - Packaging bag and process for the continuous manufacture of a plurality of bags of this type - Google Patents

Description

TECHNICAL AREA

The invention relates to the technical sector of bags for packaging food products.

More particularly, the invention finds an advantageous application in the field of bags made of flexible material, in particular obtained from a strip of film with a thickness less than approximately 250 μm.

The invention relates more particularly to a packaging bag of the aforementioned type, the recycling of which is facilitated, as well as a method for the continuous manufacture of a plurality of packaging bags of this type.

PRIOR ART

It is known from the prior art a packaging bag comprising a front wall and a rear wall, optionally connected by gussets, a bottom, and a filling opening.

This type of bag is generally made continuously, from a plastic film, such as polyethylene, optionally complexed with other materials.

During its manufacture, and in a known manner, the plastic film is continuously subjected to successive folding and welding, or gluing, or other operations to produce the various constituent parts of the bag.

The drawback of the prior art lies mainly in the difficulty of recycling this type of packaging bag, while making it possible to meet other constraints, such as the preservation of the products packaged in the bag, the visual commercial communication present on the outer walls of the bag, the filling, etc.

It is known the document DE1586521 which describes the preamble of claim 1.

DISCLOSURE OF THE INVENTION

One of the aims of the invention is therefore to remedy the aforementioned problems by providing a packaging bag whose recycling is facilitated, while making it possible to respond in an optimal manner to the constraints of the desired application.

For this purpose, a packaging bag according to claim 1 has been developed comprising, in a known manner, an outer bag comprising a front wall and a rear wall, connected by gussets, a bottom, and an opening filling.

According to the invention, the packaging bag also comprises an inner bag also comprising at least a front wall and a rear wall, connected by gussets, a bottom, and a filling opening. The inner and outer bags are attached to each other, at least at their filling opening, by temporary attachment means. The front and rear walls of the inner bag are superposed with the front and rear walls of the outer bag, and the gussets of the outer and inner bags are superposed and nested one inside the other.

In this way, the inner bag can have characteristics and properties suitable for the desired application, while the outer bag can have other characteristics and properties to be used, for example, for commercial communication purposes, in particular by printing. of its outer surface.

It is apparent from the above that after using the bag, it is possible to detach the inner and outer bags to process and recycle them separately.

The inner and outer bags are attached to each other by any suitable technique and, for example, by gluing, localized welding, or localized lamination. The essential lies in the fact that a user, after use, can manually detach and separate the inner and outer bags from each other, with a view to their separate recycling.

The inner and outer bags are attached to each other at least at their filling opening, but can also be attached to each other at their bottom, or their front and back walls, for example in their middle, on their edges, etc.

Depending on the desired application, the inner and outer bags can each be made from a single film, and can for example be made of identical or different materials. The inner and outer bags can also each consist of a multilayer film, without departing from the scope of the invention.

According to the invention, the outer and inner bags have flat bottoms folded together and glued to the front or rear wall of the outer bag by means of an attached band.

In this configuration, the attached strip may include cutting or tearing means to release the folded bottoms and facilitate the separation of the inner and outer bags.

The invention also relates to a method for the continuous manufacture of a plurality of such packaging bags according to claim 6, in which the packaging bags are made continuously from a first strip of a film intended to form the outer bags on which is positioned a single second strip of a film intended to form the inner bags, the second strip being attached to the first strip with temporary attachment means positioned on areas of the first and second strips intended to be positioned at the filling openings of the inner and outer bags, the first and second strips then undergo successive folding, welding and cutting operations to form the packaging bags.

The second strip is unrolled continuously and positioned and tied over the first strip.

According to a particular technique, during the successive folding operations, the longitudinal edges of the second strip are folded towards each other and fixed together, and the longitudinal edges of the first strip are folded towards each other and fastened together, to define the front and rear walls of the inner and outer bags.

In order to facilitate the operation of fixing the longitudinal edges of said first and second strips, the second strip is, for example, positioned on the first strip with a lateral offset so as to facilitate the operation of fixing the longitudinal edges between them of said first and second bands. Indeed, during folding, one of the longitudinal edges of the second strip overlaps the opposite longitudinal edge, and one of the longitudinal edges of the first strip overlaps the opposite longitudinal edge.

Furthermore, to close the bottom of the inner and outer bags previously shaped and arranged one inside the other, the method comprises a step consisting in folding the bottoms of the inner and outer bags together and gluing them to the front or rear wall of the outer bag via an attached band.

DESCRIPTION OF FIGURES

• La figure 1 est une représentation illustrant, en perspective, un sac d'emballage;
• La figure 2 est une représentation illustrant en détail les ouvertures des sacs interne et externe ;
• La figure 3 est une représentation illustrant le déroulement en continu des première et deuxième bandes, la deuxième bande étant attachée à la première bande avec un décalage latéral ;
• La figure 4 est une représentation schématique en perspective illustrant le déroulement en continu d'une première bande et le positionnement et la fixation d'une pluralité de deuxièmes bandes sous forme de feuilles sur la première bande, avec un décalage latéral ;
• La figure 5 est une représentation en perspective illustrant le repliage des bords longitudinaux des première et deuxième bandes, en chevauchement les uns sur les autres pour constituer le corps du sac ;
• La figure 6 est une représentation schématique en coupe longitudinale illustrant le repliage des fonds des sacs externe et interne en vue de les coller sur la paroi arrière du sac externe par l'intermédiaire d'une bande rapportée ;
• La figure 7 est une représentation schématique en perspective illustrant le sac d'emballage selon l'invention, dont le fond est refermé avec une bande rapportée.

Other advantages and characteristics of the invention will emerge better from the description which follows, given by way of non-limiting example, from the appended figures in which:

• There figure 1 is a representation illustrating, in perspective, a packaging bag;
• There picture 2 is a representation illustrating in detail the openings of the inner and outer bags;
• There picture 3 is a representation illustrating the continuous unwinding of the first and second strips, the second strip being attached to the first strip with a lateral offset;
• There figure 4 is a schematic representation in perspective illustrating the continuous unwinding of a first strip and the positioning and fixing of a plurality of second strips in the form of sheets on the first strip, with a lateral offset;
• There figure 5 is a representation in perspective illustrating the folding of the longitudinal edges of the first and second strips, overlapping one over the other to constitute the body of the bag;
• There figure 6 is a schematic representation in longitudinal section illustrating the folding of the bottoms of the outer and inner bags with a view to gluing them to the rear wall of the outer bag by means of an attached band;
• There figure 7 is a schematic representation in perspective illustrating the packaging bag according to the invention, the bottom of which is closed with an attached band.

DETAILED DESCRIPTION OF THE INVENTION

With reference to figures 1 and 2 , the invention relates to a packaging bag (1) consisting of an outer bag (2) and an inner bag (3), attached to each other, at least at their opening (2nd 3e) filling, by means (5) of temporary attachment.

Thus, after using the packaging bag (1), the user can detach the inner bag (3) and easily process the outer (2) and inner (3) bags separately from each other for their recycling.

More specifically, the inner (3) and outer (2) bags are each made from a film, for example with a thickness of less than 250 μm, and subjected to known and successive folding and welding operations, with a view to to form bags each comprising a front wall (2a; 3a) and a rear wall (2b; 3b) connected by gussets (2c; 3c), a bottom (2d; 3d), and an opening (2e; 3e) filling.

The film constituting each of the inner (3) and outer (2) bags can be of any suitable type, depending on the desired application.

For example, the inner (3) and outer (2) bags are made of identical or different materials. Furthermore, the film constituting the inner (3) and outer (2) bags can be a multilayer film, or else a film consisting of a single layer.

The composition of the inner (3) and outer (2) bags depends on the desired application, and the constraints thereof, and is well known in the state of the art.

For example, the inner bag (3) can be a waterproof bag allowing a certain preservation of the products contained in the bag, while the outer bag (2) can be a bag, for example made of paper, allowing visual and commercial communication of the bag. packaging (1), and easy recycling.

The film which constitutes the inner (3) or outer (2) bags may for example be made of polyethylene or of polyethylene terephthalate, optionally complexed with polypropylene or any other material well known in the state of the art.

To attach the inner (3) and outer (2) bags to each other, it is possible to use an adhesive, glue, to produce localized welding or complexing points.

These temporary attachment means (5) allow the user to be able, after use, to manually detach and separate the inner (3) and outer (2) bags from each other.

The temporary attachment means (5) can also be positioned at all points of the front (2a; 3a) and rear (2b; 3b) walls, for example in their middle, at their edges, and also possibly at the level of the bottom (2d; 3d) of the inner (3) and outer (2) bags.

The invention also relates to a method for continuously manufacturing a plurality of packaging bags (1).

According to the method, the packaging bags (1) are made continuously from a first strip (A) of a film, unrolled continuously and intended to form the outer bags (2).

At least a second strip (B) of a film intended to form the inner bags is positioned and attached to the first strip (A) by the temporary attachment means (5).

This second strip (B) is either unique according to the invention, see picture 3 , is made up of a plurality of sheets, see figure 4 .

With reference to the picture 3 , and when the method uses a single second strip (B), the latter is unwound continuously and is superimposed on the first strip (A), in the same direction. Temporary attachment means (5) positioned on areas of the first and second strips (A, B) intended to be positioned at least at the levels of the filling openings (3rd, 2nd) of the inner (3) and outer (2) bags ) join the two bands (A, B) to each other. These temporary attachment means (5) will allow the separation of the two bags (2, 3) while having allowed the optimal use of the packaging beforehand: such as filling, pouring, ...

The first and second strips (A, B) then undergo successive folding, welding and cutting operations to form the packaging bags (1), with or without gussets (3c, 2c).

With reference to the figure 4 , and when the method uses second strips (B) in the form of a plurality of sheets, the latter is positioned and attached at regular intervals to the first strip (A). Each sheet has a surface corresponding to the desired surface of the inner bag (3).

The inner (3) and outer (2) bags, of course of complementary and adjusted dimensions, can both comprise flat bottoms (2d; 3d).

With reference to the figure 5 , and during the successive folding operations, the longitudinal edges (B1, B2) of the second strip(s) are folded towards each other and fixed together, for example by welding or any other technique, and the longitudinal edges (A1, A2) of the first strip (A) are folded towards each other and fixed together, for example by welding or any other technique, to define the front (3a, 2a) and rear (3b) walls , 2b) inner (3) and outer (4) bags.

To facilitate this operation, the first and second bands (A, B) can be positioned on top of each other with a lateral offset, see figures 3, 4 And 5 , so as to create areas of overlap between the longitudinal edges (A1, A2) and (B1, B2) of each strip (A, B).

After these operations, an inner bag (3) is obtained superimposed on the outer bag (2), with the bellows (2c; 3c) of the two bags nested one inside the other.

With reference to figure 6 And 7 , and to close the bottom (3d, 2d) of the inner (3) and outer (2) bags previously shaped and arranged one inside the other with the method implementing a single second strip (B), the method comprises a step consisting in folding together the bottoms (3d, 2d) of the inner (3) and outer (2) bags and in gluing them to the front (2a) or rear (2c) wall of the outer bag (2) via of an added band (C).

The attached band (C) advantageously comprises means (6) for cutting or tearing, such as a pre-cut line, a tab, etc. to release the folded bottoms (3d, 2d) and facilitate the separation of the bags internal (3) and external (2).

According to the invention where the method implements a single second strip (B), unrolled continuously, the latter can be attached to the first strip (A) only at the level of zones intended to be positioned at the level of the filling openings (3rd, 2nd) of the inner (3) and outer (2) bags, since the bottoms (3d, 2d) of the bags are closed by folding as mentioned above.

On the other hand, in the case where the method uses a plurality of second strips (B) in the form of sheets, the latter is attached to the first strip (A) on areas intended to be positioned at the level of the filling openings (3rd, 2nd) inner (3) and outer (2) bags, and bottoms (3d, 2d).

Claims (8)

1. Food packaging bag (1) comprising an outer bag (2) comprising a front wall (2a) and a back wall (2b), connected by gussets (2c), a bottom (2d), and a filling opening (2e), an inner bag (3) comprising at least a front wall (3a) and a back wall (3b), connected by gussets (3c), a bottom (3d), and a filling opening (3e), wherein the inner (3) and outer (2) bags are attached to each other, at least at the level of their filling openings (2e; 3e), by temporary attachment means (5), the front (3a) and back (3b) walls of the inner bag (3) are superimposed with the front (2a) and back (2b) walls of the outer bag (2), and the gussets (2c; 3c) of the outer (2) and inner (3) bags are superimposed and nested into each other, characterized in that the outer (2) and inner (3) bags have flat bottoms (2d; 3d) folded together and adhered to the front (2a) or back (2b) wall of the outer bag (2) through an attached strip (C).
2. Packaging bag (1) according to claim 1, characterized in that the inner (3) and outer (2) bags are attached to each other by adhesive, glue, or localized welding.
3. Packaging bag (1) according to any preceding claim, characterized in that the inner (3) and outer (2) bags are also attached to each other at their front (2a; 3a) and back (2b; 3b) walls and/or at their bottom (2d; 3d).
4. Packaging bag (1) according to any preceding claim, characterized in that the inner (3) and outer (2) bags are made of different materials.
5. Packaging bag (1) according to claim 1, characterized in that the attached strip (C) includes means (6) for cutting or tearing to release the folded bottoms (2d; 3d) and facilitate the separation of the inner (3) and outer (2) bags.
6. Continuous manufacturing method of a plurality of packaging bags (1) according to claim 1, characterized in that the bags (1) are continuously produced from a first strip (A) of a film intended to form the outer bags (2) onto which a single second strip (B) of a film, unrolled continuously, is positioned and attached to the first strip (A), said second strip (B) intended to form the inner bags (3), the second strip (B) being attached to the first strip (A) with temporary attachment means (5) positioned on areas of the first and second strips (A, B) intended to be positioned at least at the level of the filling openings (3e, 2e) of the inner (3) and outer (2) bags, the first and second strips (A, B) then undergoing successive folding, welding, and cutting operations to form the packaging bags (1) with the bottoms not yet closed, and in that, to close the bottoms (3d, 2d) of the previously shaped and arranged inner (3) and outer (2) bags, the method includes a step of folding the bottoms (3d, 2d) of the inner (3) and outer (2) bags together and adhering them to the front (2a) or back (2b) wall of the outer bag(2) through an attached strip (C).
7. Method according to claim 6, characterized in that, during the successive folding operations, the longitudinal edges (B 1, B2) of the second strip (B) are folded towards each other and fixed together, and the longitudinal edges (A1, A2) of the first strip (A) are folded towards each other and fixed together, to define the front (3a, 2a) and back (3b, 2b) walls of the inner (3) and outer (2) bags.
8. Method according to claim 7, characterized in that the second strip (B) is positioned on the first strip (A) with a lateral offset to facilitate the operation of fixing the longitudinal edges (A1, A2 - B 1, B2) of said first and second strips (A, B) together.

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