EP0362102A1 - Method and device for improving the rigidity of a thermoplastic container - Google Patents

Abstract

PCT No. PCTFR/89/00468 Sec. 371 Date Jul. 26, 1990 Sec. 102(e) Date Jul. 26, 1990 PCT Filed Sep. 15, 1989 PCT Pub. No. WO90/03263 PCT Pub. Date Apr. 5, 1990.The stiffness of a flexible, substantially parallelepipedal container formed by shaping and welding a film which is made of a synthetic material and which is to enclose a liquid to be packaged, is improved by applying, before shaping, a second layer of a film formed of an identical or a different material, as a top film, to the surface of the film forming the container which does not subsequently come into contact with the liquid to be packaged. The top film includes a plurality of strips corresponding to the vertical surfaces of the final container which are welded to the film forming the container before shaping, along lines corresponding to the edges of the final parallelepipedal container.

Description

The subject of the present invention is a method and a device for improving the rigidity of a substantially parallelepipedal plastic container, said container being obtained by shaping and welding from a film made of said synthetic material and enveloping the liquid to be condition.

It also relates to the containers thus obtained.

Processes and devices of this type are already generally known in themselves.

They have, for example, but not limited to, been the subject of patents and / or patent applications in the name of the applicant.

Thus, in patent FR 2,554,785, a method has been proposed for attaching a rigid or semi-rigid handle to a bag made of flexible synthetic material. This remains relatively complex to implement due to the compatibility problems between the different materials used. On the other hand, stiffening is strictly linked to gripping, and said stiffening is not ensured on all faces in a uniform manner.

In patent FR 2 577 893 in the name of the applicant, it has been proposed to provide a flexible cushion with rigid stiffening and stabilization means, or even ribs made of material with the film. The implementation remains industrially delicate.

By application FR 2 611 163, still in the name of the applicant, it is planned to conform a cushion filled with the liquid to be conditioned, then to grip said cushion and to conform it by a sleeve made of stretchable synthetic material cold formed by jaws movable in translation and in separation with respect to each other. This device is satisfactory but is capable of improvement in terms of subsequent interventions, because here stiffening occurs on the cushion, already filled, which is a source of potential problems on the container of said cushion.

The object of the invention is to remedy these drawbacks of the prior art, by proposing a method and a device making it possible to obtain a substantially parallelepipedic container rigidified equally on its four vertical faces.

According to the invention, this result is obtained with a method for improving the rigidity of a container substantially flexible parallelepipedic being obtained by shaping and welding from a film made of said synthetic material and enveloping the liquid to be packaged, characterized in that it consists in bringing before conformation on the face of said film not subsequently coming into contact with the liquid for conditioning a second layer of a film of identical or different material, qualified as an over-film, said over-film consisting of multiple bands corresponding to the vertical faces of the final bag, said bands being welded to said film before its conformation according to lines corresponding to the edges of the final parallelepiped container.

The invention also relates to a device for implementing said method, device characterized in that it comprises, in an assembly of a first film of flexible synthetic material in containers, a second assembly for supplying over-film taking place perpendicular or parallel to said first film, said second film being attached to the first film by longitudinal and transverse welds corresponding to the edges of the final parallelepiped container.

Advantageously, the over-film can be printed and will act as a label.

• - la figure 1 est une vue schématique de deux variantes de mise en oeuvre du procédé selon l'invention ;
• - la figure 2 est une illustration de la conformation d'un film obtenu par le procédé de la figure 1 ;
• - la figure 3 illustre les étapes ultérieures à savoir :
  • . figure 3A : remplissage puis soudure transversale et découpe,
  • . figure 3B : sachet avant conformation définitive,
  • . figure 3C : formation des cornes et découpes de celles-ci,
  • . figure 3D : structure finale du conteneur.

The invention will be better understood with the aid of the description below of an embodiment given by way of nonlimiting example, made with reference to the appended drawings in which:

• - Figure 1 is a schematic view of two alternative embodiments of the method according to the invention;
• - Figure 2 is an illustration of the conformation of a film obtained by the method of Figure 1;
• - Figure 3 illustrates the subsequent steps, namely:
  • . FIG. 3A: filling then transverse welding and cutting,
  • . Figure 3B: bag before final conformation,
  • . FIG. 3C: formation of the horns and cutouts thereof,
  • . Figure 3D: final structure of the container.

We will first refer to Figure 1.

There is shown a roll (1) of main film (2) whose "lower" face (3) will come into contact with the liquid to be packaged.

On the "upper" face (4) is reported an over-film (5) unwound from a reel unwinding such that (6) perpendicular to the path of the film (2) or (7) parallel to the path of said film ( 2).

The over-film (5) is placed on the film (2), cut by an assembly (8) schematically represented and welded to said film along longitudinal lines (9,10,11,13,14) and two transverse lines ( 15.16).

All these operations are carried out in an indexed manner, so that there is successively advance of the film (2), advance of the film (5), cutting of the necessary strip length, welding of the different lines, then advance of the film again ( 2).

Downstream, provision will be made for the installation of a closure cap (17), for example as described in patent FR 2,600,974 in the name of the applicant.

Then the film (2) provided with its over-film and the welds (9,14) determining three main panels (18,19,20) and two side half-panels (21,22) is brought to a conformator (23) shown in figure 2.

This conformator is of the type described in patent FR 2,554,785 in the name of the applicant and will therefore not be described in more detail.

The panels delimited by the vertical welds determining the vertical faces of the final container. The side half-panels will be welded together and may on this occasion tighten a ring (24) for gripping the final container.

The two side half-panels (21, 22) are thus interconnected and form one face of the final bag by vertical welding on the former (23).

Then conventionally, there is filling of the sheath thus shaped (25), transverse welding and cutting in (26) shown in Figure 3A to arrive at the unit (27) of Figure 3B.

It remains to conform the horns by welding-cutting according to for example patent FR 2 566 321 in the name of the applicant (FIG. 3C) to arrive at the final packaging (28) shown in FIG. 3D.

Note that the set operates sequentially and indexed.

Between each strip of over-film attached to the main film, there remains an area to which the sealing cap is attached and which will serve, by cooperating for this purpose with the previous one, to form the bottom, the top and the horns of the container. .

Claims (7)

1 ° Method for improving the rigidity of a substantially parallelepipedic flexible container being obtained by shaping and welding from a film made of said synthetic material and enveloping the liquid to be packaged, characterized in that it consists in bringing back before shaping on the face of said film (2) not subsequently coming into contact with the liquid to be conditioned, a second layer of a film (5) of identical or different material, qualified as an over-film, said over-film consisting of multiple bands corresponding to the vertical faces of the final bag, said strips being welded to said film before its conformation along lines corresponding to the edges of the final parallelepiped container. 2. Method according to claim 1, characterized in that the over-film (5) is brought onto the film (2) parallel to the latter. 3 ° Method according to claim 1, characterized in that the over-film (5) is brought onto the film (2) perpendicular thereto 4 ° Method according to any one of claims 1 to 3, characterized in that the over-film (5) is placed on the film (2), cut by an assembly (8) schematically shown and welded to said film according to longitudinal lines (9,10,11,13,14) and two transverse lines (15,16). 5 ° Method according to claim 4, characterized in that the operations are carried out in an indexed manner, so that there is successively advance of the film (2), advance of the film (5), cutting of the necessary strip length, welding different lines, then advance again from the film (2). 6 ° Method according to any one of claims 1 to 5, characterized in that the film (2) provided with its over-film and the welds (9,14) determining three main panels (18,19,20) and two side half-panels (21,22) is brought to a shaping device (23). 7. Device for implementing the method according to any one of claims 1 to 6, characterized in that it comprises, in an assembly of a first film of synthetic material flexible in containers, a second set (6) of over-film supply taking place perpendicular or parallel to said first film, said second film being attached to the first film by longitudinal welds corresponding to the edges of the final parallelepiped container.

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