EP0170570B1 - Packaging for preserving the condition of objects with different volumes, and process for their manufacture - Google Patents

Abstract

1. Packaging for packing batches of objects of differing volumes, of the type comprising an American case (1) or the like and a film (2) of heat-shrinkable plastics material firmly connected to the base of the case, characterized in that the film (2) of plastics material is gripped between the outer flaps (3), which adjoin two parallel walls of the case and constitute the actual base of the packaging, and the inner flaps (5), which adjoin the two other walls and line this base internally.

Description

The present invention relates to a packaging for packaging batches of objects having different volumes. It also relates to a method of manufacturing such packaging.

It frequently happens that manufacturers of products or wholesalers, for example in the field of perfumery or pharmacy, have to package in cardboard packaging, corrugated cardboard or another semi-rigid material, lots of objects whose volume varies according to the recipients and can sometimes be relatively unimportant. It is clear that it is not possible for them to use for each order a packaging specially adapted to the volume of the batch considered, because that would suppose that they have extremely varied packaging and, even if it were the case, the choosing a packaging corresponding precisely to the volume to be conditioned would considerably complicate the handling operations.

To overcome this drawback, it has been proposed to use standard volume packaging, for example an American box, at the bottom of which the objects are stored, and to wedge these objects therein using filling materials such as papers, wood chips, plastic particles or various synthetic debris. However, this process is impractical, since the packaging operations cannot be automated. In addition, unloading, carried out manually, is complicated by the presence of the cushioning material, which must be cleared beforehand and which is difficult to handle.

In order to avoid these drawbacks, it has been proposed to house the objects to be packaged in trays comprising two raised walls, then to pass a film of heat-shrinkable material below the bottom of the tray to fold it above objects, after passing over the walls the lower ones. By causing the shrinkage of the plastic film, the objects are pressed against the bottom of the tray and the latter can then be introduced laterally into an American box of internal dimensions corresponding to the overall dimensions of the tray.

Such a method of packaging is however expensive and the resulting packaging has limited resistance to vertical compression, since only the raised walls of the tray contribute to it.

In order to strengthen the resistance to vertical compression of trays of this type equipped with a heat-shrinkable film, French patent N ° 2498561 proposed to cover the full tray with a cardboard or corrugated element with a U-section, the parts corresponding to the branches of the U have a height equal to that of the highest walls of the tray. The cost of such packages is moderate, but their resistance to vertical compression remains unimportant, which affects the stacking of full packages.

In French patent N _° 2,426,620, as well as in French patent N ° 2,506,722 of the Applicant, there are also described packages, in particular American cases, equipped with a film of a heat-shrinkable material but in which the film is glued either on the internal face of the bottom or internal flaps adjoining the side walls and applied against the bottom, or on the base of the internal faces of the side walls.

With such a packaging method, however, the products to be packaged can only have a relatively moderate weight, because, in the event of a fall or a violent impact on the packaging, there are significant risks of detachment of the plastic film. and packaging at the bonding points.

The present invention relates to cardboard or corrugated cardboard packaging, in particular American boxes of the type in which a film of heat-shrinkable plastic material is secured to the bottom part. The invention more specifically aims to strengthen the assembly of the film and the packaging, while proposing an assembly capable of being produced at high speed and, consequently, of low cost, which is capable of being filled and mechanically closed, regardless of the volume of the batch of objects to be packaged.

To this end, the subject of the invention is a packaging for packaging batches of objects of different volumes, of the type comprising an American box or the like and a film of heat-shrinkable plastic material secured to the bottom of the box, characterized in that the plastic film is pinched between the outer flaps, adjoining two parallel walls of the box and constituting the bottom proper of the package, and the inner flaps, adjoining the other two walls and lining this bottom internally.

Due to the fact that it is trapped between the bottom and the interior flaps of the box, on which the conditioned objects rest, the heat-shrinkable e film will not risk accidentally detaching from the packaging, especially since after thermore- traction, it will tightly grip the inner flaps. This produces a much more reliable packaging than those in which one or more plastic films are glued against the bottom or against the side walls of the American box.

Naturally, when we speak of an American box or the like, in the definition of the invention, we mean any packaging made of cardboard, corrugated cardboard or other semi-rigid material, in which a bottom part is lined internally by adjoining flaps. with two side walls. It is clear, however, that, because of their wide distribution and their ease of manufacture, the American cases themselves will be preferred within the framework of the invention.

Advantageously, in the case where it will prove necessary to reinforce the securing of the plastic film to the bottom part, in particular in the case where the batch of objects is placed in the center of the packaging and when the packaged products are relatively heavy, we can fix the plastic film on the inner part of the outer flaps constituting the bottom or, preferably, on your face of the inner flaps facing towards the bottom by gluing for example. This collage aims essentially to maintain the film contiguous to the lower edges of the box, and to prevent it from sliding transversely towards the central part of the packaging, which would have the effect of releasing the locking in position which it exerts on the packaged products. This bonding therefore has only an auxiliary role of maintaining in position of the objects at the bottom of the packaging, by laterally retaining the film, which is pinched between the bottom and the internal flaps of the packaging.

These flaps will preferably be joined, but the choice of the precise type of packaging in cardboard or corrugated cardboard will depend on the nature and volume of the products packaged, since a relatively large object, resting on both flaps at the same time, will not require adjoining flaps.

Usually, the packaging will be formed at its lower part (outer flaps at the bottom of the American body) and at its upper part (outer flaps at the upper face), using adhesive or gummed tape. Bonding can be carried out using “Hot Melt” or cold glue.

The packaging according to the invention can be produced by various methods. Advantageously, however, the following process can be used, which constitutes another object of the invention.

This process is characterized in that, the packaging being open at its upper part and at its lower part, the film of heat-shrinkable plastic material, unwound from a reel using a drive means, is lowered inside the package using a piston or the like, parallel to two opposite side walls, until it exceeds the free edge of the flaps, in that the two flaps adjoining the other two side walls , preferably those having the smallest width, are then folded towards the inside of the packaging perpendicular to the adjoining walls and are optionally glued in spots on their external face, in that the film is then brought back into contact with the external face. previously folded flaps, in that the other two flaps are folded in turn and applied against the outer face of said film, and in that the latter is cut laterally, so as to define parts intended to be folded back nt on conditioned objects, prior to shrinking the plastic film.

Such a process is therefore simple and easy to implement using a fully automated process and the packaging thus produced will lend itself to easy semi-automated and safe packaging of batches of objects of different volumes. .

Of course, the process which has just been defined has no limiting character and those skilled in the art will be able to design other methods of manufacturing the packaging which is the subject of the present invention.

• La figure 1 est une vue en perspective de l'emballage conforme à l'invention;
• Les figures 2, 3 et 4 illustrent le procédé de mise en oeuvre de cet emballage;

This will be described below in more detail, with reference to the appended schematic drawings, in which:

• Figure 1 is a perspective view of the packaging according to the invention;
• Figures 2, 3 and 4 illustrate the process for implementing this packaging;

Figures 5 to 8 are schematic vertical sections illustrating a mechanization of this process.

As can be seen in FIG. 1, the packaging in accordance with the invention comprises an American box 1 and a film of heat-shrinkable plastic 2. This film is pinched between the bottom proper of the box, constituted by the external flaps 3 adjoining the side walls 4 (preferably the widest), these flaps 3 being assembled together by an adhesive tape not shown, and the internal flaps 5, adjoining the side walls 6 of the body.

As shown diagrammatically in FIGS. 2, 3 and 4, this packaging can be produced in a simple manner by introducing the film 2 inside the box 1, open at its two ends, with the flaps 3 and 5 arranged in the extension of the adjoining walls or deviating from the plane thereof towards the outside. The film is introduced into the packaging with its two strands 2a, 2b applied to the internal face of the walls 4, until the part 2c joining the strands 2a and 2b exceeds the end of the flaps 3 and 5 (FIG. 1 ). The flaps 5 are then folded at right angles towards the inside of the box (FIG. 3), then the two strands 2a, 2b of the film 2 are then reassembled along the walls 4 (FIG. 4), so as to apply the part 2c against the external face of the flaps 5, possibly glued. The flaps 3 are then folded perpendicular to the walls 4 (FIG. 1) and assembled together by means of an adhesive strip, so that the film 2 is firmly pinched between the flaps 3 and 5, with the advantages which will result therefrom, c that is to say the elimination of the risks of separation of the film 2 and of the body.

As indicated above, in order to avoid, in certain particular cases, a lateral sliding of the film 2 towards one or the other of the walls 6, the film may possibly be made integral, for example by collage, shutters 3 or, preferably, shutters 5.

Figures 5 to 8 illustrate in schematic form a simple mechanism for implementing the method which has just been described.

The American body 1, open at its upper end, is positioned using a system of guides 10 below a piston 11, of section substantially equal to the internal cross section of the body. The film 2 is unwound below the piston 11 from a reel 12, passing over relay rollers such as 13, using a clamp 14 controlled by a jack 15. A counterweight 16 exerts on the film 2 a pull, against the jack 15.

In order to facilitate the introduction of the piston 11 into the box 1, as well as the positioning of the products to be packaged, the upper flaps of the American box will preferably be applied laterally against the external face of the side walls, as shown in the figure. 7. For this purpose, two adjoining flaps with two contiguous side walls may advantageously, in a manner known per se, be integral with one another at their free edge, the cut which separates them not extending up to at this edge. The case being flattened, the flaps are applied against the side faces and the box is then opened.

The piston 11 is then introduced into the box 1 (FIG. 6) by pushing the film 2 inside of it, until it exceeds the lower end of the lower flaps 3 and 5.

The two strands of the film 2 which protrude from the lower part of the packaging are then separated from each other, for example using a system of suction cups 17 controlled by jacks 18, which will have for effect of spreading the flaps 3 from one another.

The flaps 5 are then folded towards the inside of the American box, perpendicular to the adjoining walls, using a system of pressing pads or the like and their external face is optionally glued (FIG. 8). The action of the suction cups 17 is then eliminated, the piston ¹¹ is raised to an intermediate stage and, by acting on the counterweight 16 (or using an auxiliary motor), the film 2 is also raised until its lower part comes into contact with the external face of the flaps 5 (FIG. 8), pressing pads 19 then fold the flaps 3 against the film 2.

The flaps 3 are then assembled using an adhesive tape or Hot Melt or cold bonding (not shown) and the film 2 is cut using a knife 20.

The products to be packaged are then placed in the packaging and the parts 2a and 2b of the heat-shrinkable film are folded over these products. A pulsation of hot air is then sufficient to ensure the self-welding of the parts 2a and 2b and the retraction of the film.

It can be seen that such a system can be implemented semi-automatically, that is to say with the packaging shaped manually by the operator and introduced by the latter at the position for placing the film, or automatically, the American box being then distributed flat from a store and set up in the usual way using suction cups.

The process which has just been described uses only one plastic film, but it would not go beyond the scope of the invention to use two films, unwound from two reels, the ends of which, after overlapping, are pressure welded to the outside of the internal flaps 5.

It will be appreciated that the placement of the products to be packaged and the shrinkage of the plastic film are carried out very easily using the packaging according to the invention and that this packaging is much more reliable than similar packaging in the art. anterior.

Claims (4)

1. Packaging for packing batches of objects of diffenng volumes, of the type comprising an American case (1) or the like and a fil'm (2) of heat-shrinkable plastics material firmly connected to the base of the case, characterized in that the film (2) of plastics material is gripped between the outer flaps (3), which adjoin two parallel walls of the case and constitute the actual base of the packaging, and the inner flaps (5), which adjoin the two other walls and line this base internally.

2. Packaging according to claim 1, characterized in that the inner flaps (5) of the case adjoin the narrower walls.

3. Packaging according to claim 1 or claim 2, characterized in that the film (2) of plastics materials is fixed to the inner faces of the outer flaps (3) or, preferably, to the outer faces of the inner flaps (5), especially by adhesion.

4. A process for manufacturing packaging according to any one of claims 1 to 3, characterized in that, with the packaging open at its upper and lower parts, the film (2) of heat-shrinkable plastics material, unwound from a reel (12) with the aid of a drive means (14,15), is lowered into the packaging (1) by means of a piston (11) or the like, in parallel with two opposed lateral walls, until it projects beyond the free edge of the flaps, in that the two flaps (5) adjoining the other two lateral walls, preferably the narrower ones, are then folded to the inside of the packaging at right angles to the adjoining walls and are optionally spread with glue at points on their outer faces, in that the film (2) is then brought into contact with the outer faces of the previously folded flaps (5), in that the two other flaps (3) are in turn folded and applied to the outer face of the said film (2) and in that this film (2) is cut off laterally to define parts intended subsequently to be folded down on the packaged objects, prior to shrinkage of the plastics film.

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