FR3037932B1 - PACKAGING BAG OF PLASTIC MATERIAL COMPRISING TWO WALLS FORMING SIDE EDGES, BACKGROUND AND FILLING OPENING - Google Patents

Abstract

The plastic packaging bag (1) comprises two walls (1a) and (1b) forming side edges, a bottom (1c) and an opening (1f) for filling. The side edges have bellows (1c) and (1d), while part of the internal face of the walls, at one of the bellows (1c) at least, comprises a continuous support band (2b), equipped additional temporary coupling means (2a). The complementary coupling means (2a) have interruptions (2c) and (2d) located only in the connection zone of the bellows (1c) with the part of the internal face of the walls, so that said means (2a) constitute three separate distinct zones, the support strip (2) remaining continuous.

Description

The invention relates to the technical sector of plastic packaging bags.

This type of bag comprises, in a manner perfectly known to a person skilled in the art, a front wall and a rear wall assembled at their lateral sides, in combination with bellows, delimiting a bottom and a filling opening.

These bags are generally preformed, and produced continuously, from a single plastic film, such as PE with or without OPP added, or else PE added with PET, without excluding other commonly used materials. used in the field of food packaging.

Still in known manner, the plastic film is continuously subjected to successive folding and welding operations in order to produce the various constituent parts of the bag, as specified above. The external folds, at the connection of the bellows and the walls, are assembled by continuous welding lines. The bottom of the bag can be made by any known and appropriate means, for example, by a folding operation, or by means of an attached strip fixed flat after having folded the bellows.

It has also been proposed to equip this type of bag at the filling opening, that is to say opposite the bottom, with a temporary closure system, capable of creating a temporary opening. giving free access to the interior of the bag for the pouring of products, said opening being capable of being, therefore, closed and re-opened at will.

A solution emerges, for example, from the teaching of patent FR 2 816 597, belonging to the Applicant.

According to the teaching of this patent, the packaging bag has, in particular at its upper transverse edge, arrangements capable of being torn to give free access to the interior of the bag, delimiting an opening, which is equipped with complementary means of temporary connections, of the hermaphrodite type being able to be engaged and disengaged at will, in order to ensure the closure or not of said opening. In this case, the opening is likely, therefore, to act as a spout. These complementary means of temporary connections, of the hermaphrodite type, are essentially constituted by a continuous support strip fixed inside the bag, as will be described below. This support strip has the complementary coupling means of the hermaphrodite type as such, for example in the form of a “zip®”, or of a multiplicity of heads in relief, regularly spaced, and capable of being engaged, under an effort. pressure, in the spaces separating said heads.

In the case where this closure system is intended to act as a pouring spout, the strip, equipped with complementary coupling means, is fixed to the internal walls of the bag, at the connection of the front and rear faces, with the edges shaped in bellows.

Figure 1 shows an example, according to the prior art, of a method of manufacturing a bag from a plastic film, with the establishment of a closure system (2). In this figure, (A) and (B) represent the front and rear walls of the bag, (C) and (D), the side bellows. The band (2b) of the closure system equipped with complementary coupling means of the hermaphrodite type (2a), is fixed at the connection of the walls (A) and (B), and the bellows (C).

For the production of certain bags, it is necessary, by construction, to include falls, at the closing edges of the bag (S), which are welded. This results in a production difficulty when the closure system is positioned at the bellows, as indicated, since the latter is also subjected to the welding operation, while the complementary coupling means appear in excess thickness.

In order to remedy this drawback, with the aim of overcoming this problem of excess thickness of the coupling means, it has been proposed to subject them to crushing by ultrasound. This results in an additional and costly operation, with results which are not always satisfactory.

Note also that in the case where the construction requires falls at the edges, as illustrated in Figure 1, it is not possible to interrupt the welding at the closure system.

The purpose of the invention is to remedy these drawbacks in a simple, safe, efficient and rational manner.

The invention finds an advantageous application, in the case of a plastic packaging bag, of the type of those comprising two walls forming lateral edges, a bottom and a filling opening, said lateral edges having bellows, while that a part of the internal face of the walls, at at least one of the bellows, comprises a continuous support strip, equipped with complementary temporary coupling means.

According to the invention, in order to solve the problem posed of overcoming the additional thickness of the complementary coupling means, said complementary coupling means have interruptions situated only in the zone of connection of the bellows with the part of the internal face of the walls, so that said means constitute three separate distinct zones, the support strip remaining continuous.

It follows from these characteristics that it is possible to continuously produce a weld line at the edges, without any interruption, including at the closure system.

According to another characteristic, a weld line is formed at the connections of the bellows with the walls, including at the location of the interruption of the complementary coupling means.

As indicated, the complementary coupling means are of the hermaphrodite type, for example in the form of a rib and complementary groove known under the trademark "ZIP", of a multiplicity of regularly spaced raised heads.

The invention is set out below in more detail with the aid of the figures of the appended drawings in which:

FIG. 1 is a plan view showing an example of a method for manufacturing a bag from a plastic film, according to the prior art, with fixing, at the time of manufacture, a closure system, at the connection of the two walls with one of the bellows,

FIG. 2 is a view similar to FIG. 1, showing, according to the invention, the interruption of the complementary coupling means to allow continuous welding,

- Figure 3 is a perspective view of an exemplary embodiment of a packaging bag, equipped with the closure system.

As shown in FIG. 3, in a known manner, the packaging bag obtained from a plastic film (1) has a wall (la), a wall (1b) assembled at their lateral sides, in combination with bellows (le) and (Id).

The bag also has a bottom (le) and a filling opening (If).

A part of the internal face of the front (la) and rear (1b) walls, at at least one of the bellows (le), receives a system (2) in the form of a continuous support strip (2b), equipped with additional temporary coupling means (2a) to constitute, in a known manner, a system for opening and closing the bag, after, for example, tearing an area (1g) formed, in a known manner, at the level of the bag filling opening.

According to the invention, the complementary coupling means (2a) have interruptions (2c) and (2d) located only in the area of connection of the bellows (le) with the walls (la) (1b).

It follows from these characteristics that the complementary coupling means (2a) are distributed according to three distinct and separate zones (a) (b) (c) corresponding respectively to a part of the internal face of the wall (la), to the bellows (le), and part of the internal face of the wall (1b).

The support strip (2) is produced continuously, without any interruption. We refer to Figure 3.

It therefore appears that the weld lines (S) can be formed at the connection of the bellows (le) and (Id) with the walls (la) and (1b), including at the location of the interruptions (2c) and (2d) complementary coupling means (2a), since there is no longer any additional thickness following the removal of the complementary coupling means at the weld lines.

These arrangements prove to be particularly advantageous in the case of a manufacturing process in accordance with that illustrated in FIG. 2, particularly suitable for producing a flat bottom by means of an attached strip, after having made a cross section at the level of the 'one of the walls and bellows, then proceeded to a folding of the bellows for fixing a strip constituting said bottom, by any known and appropriate means. This strip has a dimension generally greater than that of the bottom. After folding, we cut the edges and cut the bottom.

The advantages are apparent from the description.

Claims (2)

-1- Plastic packaging bag (1) comprising two walls (la) and (1b) forming lateral edges, a bottom (le) and an opening (If) for filling, said lateral edges having bellows (the ) and (Id), while a part of the internal face of the walls, at the level of at least one of the bellows (le), comprising a continuous support strip (2b), equipped with additional temporary coupling means ( 2a), characterized in that said complementary coupling means (2a) have interruptions (2c) and (2d) located only in the area of connection of the bellows (le) with the part of the internal face of the walls, so that said means (2a) constitute three separate distinct zones, the support strip (2b) remaining continuous, while a weld line is formed at the connections of the bellows (le) and (Id) with the walls (la) and (Ib), including at the place of the interruption of the additional means coupling ires (2a). -2- Packaging bag according to claim 1, characterized in that the complementary coupling means (2a) are of the hermaphrodite type.