EP3102495B1 - Method for manufacturing a box and box obtained by said method - Google Patents

Description

The invention relates to a method of manufacturing a box comprising at least three at least partially rigid side flaps, said at least three side flaps being obtained by folding at least one first sheet.

It also relates to a box obtained by the process in accordance with the invention.

Such a box can be intended for packaging products or various articles, which do not need, like tin cans, to constitute an airtight package.

To condition fragile products (bottles of wine or spirits) or luxury products (perfumes, jewelry), it is planned to make boxes with rigid walls, such as boxes with metal walls, in order to better protect them or to protect them. present them in a prestigious way.

Metal boxes are usually made from a sheet of tinplate of common thickness ranging from 0.20 mm to 0.30 mm, which sheet can be decorated either by means of offset printing or by embossing, the embossing providing relief elements, additional shapes and textures.

The construction and assembly of different metal parts of the cabinet is based on purely mechanical crimping and / or stapling processes such as those described in the application. FR 2 369 167 , for example.

Such boxes have certain drawbacks: they are light in weight, they lack rigidity in their walls which float, sink or even deform when the box is gripped, and they have a sound of the “hollow shell” type. These drawbacks give the consumer an image of the box as opposed to the luxurious image given to the product it contains, which devalues the product in the eyes of the consumer.

Cases or boxes are also known, the walls of which comprise several layers, described for example in the documents US 3,064,874 , WO 97/06056 , US 3,754,456 and FR 766 947 .

The document US 3,142,406 describes a box comprising at least three at least partially rigid side flaps, in which said at least three side flaps comprise a sandwich structure comprising at least two metal outer sheets, and a securing material disposed between the two sheets, the securing material being distributed substantially over the entire surface of each of said side flaps

We finally know the document FR 1 474 812 which describes a metal box (estagnon) made from two metal plates.

It describes un.procédé manufacturing a box comprising at least three at least partially rigid side flaps, said at least three side flaps being obtained by folding at least one first sheet, the first sheet being metallic, and by the shaping of at least one second sheet, the shaping step comprising a step of folding said second sheet, the second sheet being metallic.

The invention relates to a method as defined by claim 1.

Implemented in this way, the method solves the problems of deformation and of the hollow shell which would be obtained by securing two sheets affixed one against the other and crimped together.

Preferably, the method comprises a final step of rolling at least one edge of said sandwich structure.

In addition, the method makes it possible to achieve wall stiffness levels comparable to those achieved with walls made of wood or injected plastic.

• l'étape de mise en forme peut comporter une étape de découpe de ladite seconde feuille ;
• le matériau de solidarisation peut comporter une matière adhésive ;
• le matériau de solidarisation peut comporter une matière élastique.

The method according to the invention can also comprise the following characteristics, taken separately or in combination:

• the shaping step may include a step of cutting said second sheet;
• the securing material may include an adhesive material;
• the securing material may include an elastic material.

• La figure 1 est une vue en perspective d'un coffret conforme à un mode de réalisation selon l'invention,
• Les figures 2.1 à 2.6 sont des vues en coupes de différentes parois de coffrets selon l'invention,
• La figure 3 montre différentes étapes a) à d) d'un premier procédé de fabrication d'un coffret ne faisant pas partie de l'invention, chaque étape a) à d) étant illustrée par un ou plusieurs éléments d'un coffret montrés en perspective ;
• Et la figure 4 montre deux étapes i) et ii) d'un second procédé de fabrication d'un coffret selon l'invention, chaque étape i) et ii) étant illustrée par un ou plusieurs éléments d'un coffret conforme à l'invention montrés en perspective.

In order to be able to be carried out, the invention is set forth in a sufficiently clear and complete manner in the following description which is, in addition, accompanied by drawings in which:

• The figure 1 is a perspective view of a box according to an embodiment according to the invention,
• The figures 2.1 to 2.6 are sectional views of different enclosure walls according to the invention,
• The figure 3 shows different steps a) to d) of a first method of manufacturing a box not forming part of the invention, each step a) to d) being illustrated by one or more elements of a box shown in perspective;
• And the figure 4 shows two steps i) and ii) of a second method of manufacturing a box according to the invention, each step i) and ii) being illustrated by one or more elements of a box according to the invention shown in perspective .

In the description which follows, the terms “lower”, “upper”, “upper”, “lower” etc. are used with reference to the drawings for greater ease. understanding. They should not be understood as being limitations on the scope of the invention.

The example which will now be described refers to a cabinet the walls of which are at least partially metallic.

The figure 1 shows a box 1 which is in two parts: a bottom 2, formed by a rectangular tray and a cover 3 in the form of a pyramid also with rectangular section, the end 4 of which has been truncated.

The cover 3 is associated with the bottom 2 by inserting a free lower edge 5 in a groove 6 made in the bottom 2 running along its peripheral edge 7.

The cover 3 of the box 1 comprises four side flaps 8 (therefore at least three side flaps according to the invention), and a top flap 9 whose edges 10 are integral with the upper edges 11 of each of the side flaps 8.

The side flaps 8 are obtained by folding a sheet along three edges 12, the fourth stop 12 being obtained by joining two side edges 13 free of side flaps 8.

The term “folding” should be understood to mean any folding made with the sheet: thus, a folding can make it possible to obtain two side flaps, or more, if the folding is carried out at a certain distance from the edge of the sheet. But folding can also make it possible to obtain crimping: this is achieved by folding the sheet along one of its edges, this folding being called “rolling”. The edges of two sheets folded by rolling can then be nested one in the other and crimped by crushing the rolled edges inserted one into the other.

Thus, when reference will be made to several side flaps obtained by folding at least one first sheet, it should be understood that said several side flaps can be obtained either by folding a sheet along several straight lines, or by folding the edges of several sheets and connecting them together (for example by crimping).

The top flap 9 is obtained by cutting an embossed metal sheet and it is attached to the top of the pyramid formed by the side flaps 8.

Each of the side flaps 8, as well as the top flap 9, is produced by a sandwich structure 13 which will now be described with reference to figures 2.1 to 2.6 :
Initially, the sandwich structure 13 is made large enough to form the sheet which will form the four side flaps 8.

The sandwich structure 13 comprises at least two outer layers 14 enclosing a central layer 15.

The central layer 15 is a single layer (see examples of figures 2.1 to 2.5 ) or a multilayer structure, as shown in figure 2.6 .

At least one of the outer layers 14 is a metal foil 16.

In the example shown on figure 2.4 , the second outer layer 14 is also a metal foil 16.

The second outer layer 14 can also be a plastic sheet 17 ( figure 2.3 ), a cardboard plate 18 ( figure 2.2 ) or any other rigid material forming a thin plate 19 ( figure 2.1 ). The term “thin plate” will be understood to mean a plate the thickness of which does not exceed 0.5 mm. The term “rigid” will be understood to mean a material which is difficult to deform under the action of manual pressure (as opposed to a flexible material).

When it is simple, the inner layer 15 is a material ensuring the joining of the two outer layers 14.

The securing material may be an adhesive material 20 (see figures 2.1 to 2.4 ) or an elastic material 21 such as rubber (see figure 2.5 ).

The elastic material can be introduced by injection of material between the two outer layers.

When the sandwich structure 13 comprises an outer metal layer 16 (between 0.2 and 0.4 mm), an inner layer of adhesive material 20 and a second outer layer of thin plate 19 ( figure 2.1 ), we obtain a side flap 8 having a higher weight and rigidity compared to a side flap consisting only of a metal sheet 16, without however lose the ability to decorate and emboss the standard side flaps. The higher rigidity of the side flap greatly limits the deformations when handling the box by exerting pressure on the side flaps, as well as the clicking noises normally observed during this deformation. The increase in the weight of boxes is perceived as a statutory advantage in certain markets.

The same goes for the sandwich structure shown in figures 2.3, 2. 4 and 2.5 , comprising a metallic layer 16, a layer of adhesive material 20 and a layer of plastic material 17 or another metallic layer 16, or else a layer of elastic material 21 enclosed between two metallic layers 16.

When the sandwich structure 13 comprises a metallic outer layer 16 (between 0.2 and 0.4 mm), a layer of adhesive material and a cardboard plate, a side flap 8 is obtained having a higher rigidity compared to a side flap consisting only of a metal foil 16. This higher rigidity limits deformation during handling and also clicking noises.

When the inner layer 15 is in the form of a sandwich structure, it may comprise two layers of adhesive material distributed on either side of a layer of plastic material 17 forming an insert. This assembly makes it possible to further increase the rigidity and the weight of the side flap.

The inner layer 15 (simple or sandwich structure) trapped between the two outer layers is distributed over substantially the entire surface of each of the side flaps 8. In this way, there is no side flap part 8 where the two outer layers 14 of the sandwich structure would face each other with a void between them.

Thus, the sandwich structure of the side flap gives it a certain rigidity, because the rigidity of the layers is imposed from one layer to another.

In all the examples of sandwich structures described, the modulation of the thicknesses of the two outer layers makes it possible to adjust these different parameters to the best of economic and eco-design issues.

Reference will now be made to two manufacturing processes with reference to the figures 3 and 4 . The manufacturing process according to figure 4 is in accordance with the invention.

The figure 3 shows the steps in the production of side flaps of a square section enclosure.

The sandwich structure 13 which was chosen to produce the side flaps is the one comprising two metal layers 16 joined together by a layer of adhesive material, for each of the side flaps 8.

A first metal sheet 16 shown in step a) is first of all shaped, that is to say that it is cut according to predetermined dimensions and optionally embossed in order to give it a relief which is at the same time. both decorative and stiffening.

Four second metal sheets 16 are also shaped in parallel: they are cut according to dimensions different from those of the first sheet, the dimensions of the second sheets corresponding substantially to the dimensions of each of the side flaps 8. The second sheets 16 are also optionally. embossed. If they are, they have the same embossing as that of the first metal sheet 16.

The second metal sheets will constitute, after completion of the side flaps 8, the internal face of the side flap.

On the first metal sheet 16, a layer of adhesive material is applied to four zones 22. The areas and shape of the four zones 22 correspond to the areas of the four second sheets 16. The application of the layer of adhesive material is carried out by the operator. depositing a bead of adhesive material which spreads out in a serpentine pattern over all of each of the zones 22 on the first metal sheet 16. The deposit of a bead of material spread out in a serpentine ensures the evacuation of any bubbles of air between the first metal foil 16 and each of the second metal foil 16.

Step b) consists in positioning each of the four second metal sheets 16 on each of the four zones 22 and exerting pressure on the four second sheets so that the coil of adhesive material spreads out in each of the four zones. between the first metal sheet and the four second metal sheets.

A sandwich structure 13 shown in step c) is then obtained, according to which the first sheet and the second metal sheets are joined together.

The first metal sheet 16 is then folded along three straight lines D1, D2 and D3, located between the second metal sheets 16, corresponding to three ridges delimiting the edges of the side flaps 8.

A side wall of the box is thus obtained with a square section (see step d). The fourth stop is obtained by joining the two free edges of the metal sheet 16 which face each other after folding. This joining is carried out by any means known to those skilled in the art: welding, crimping, etc.

Finally, each of the free edges 23 of the side flaps are rolled to crimp the metal sheets together.

The rolling step could also be carried out before the step of folding the first sheet without departing from the scope of the invention.

It should be understood that the rolling could also be carried out on one edge of one of the two metal sheets, not to crimp the metal sheets together, but to crimp the side flaps with the top flap 9, for example, without depart from the scope of the invention.

The figure 4 shows the steps for making the side flaps 8 of the box illustrated in figure 1 .

According to this embodiment, the side flaps 8 are also produced by a sandwich structure comprising a first outer layer forming the outer wall of the side flap, and a second outer layer forming the inner wall of the side flap.

To produce side flaps 8 forming a truncated pyramid of rectangular section, the inner and outer walls are each made from a metal sheet 16 embossed flat, then volume (step not shown).

An adhesive material 20 is then applied to the side flaps in the form of a bead extending in a serpentine pattern over the entire surface of the side flap (step i).

The two truncated pyramids are inserted by force to form the front flaps of box 1 of the figure 1 (step ii).

The free edges 5 of the side flaps are then rolled in order to ensure the crimping of the metal sheets 16 between them (see, for example, the rolled edge bearing the reference 5 on the figure 1 ).

It will be understood from the above description how the invention makes it possible to obtain a case that is more rigid and, in appearance, more resistant than those obtained by the methods of the state of the art.

Claims (5)

1. A method for manufacturing a box (1) including at least three at least partially rigid side flaps (8), said at least three side flaps (8) being obtained by folding at least one first sheet (16), said first sheet being of metal, and by shaping at least one second sheet (16-19), the shaping step includes a step of folding (i) said second sheet (16-19), said at least one second sheet (16-19) being of metal,
   said method being characterised in that it includes the following steps of:

   before folding said at least one first and second metal sheets:

   - embossing or offset printing said first metal sheet,

   - embossing or offset printing said second metal sheet,

   and after folding said at least first and second metal sheets:

   - applying a layer of a securing material (20; 21) to a surface of at least one part of said first sheet,

   - positioning said at least one second sheet (16-19) on said part of said first sheet (16) covered with said securing material (20; 21), in order to obtain a sandwich structure (13), the securing material being an internal layer (15) providing securing of two external layers (14), said two external layers being said first and second metal sheets (16, 16-19).
2. The method according to claim 1, characterised in that it includes a last step of curling at least one edge (5; 23) of said sandwich structure (13).
3. The method according to claim 1 or 2, wherein the shaping step includes a step of cutting (b) said second sheet (16-19).
4. The method according to any of the preceding claims, wherein the securing material (20; 21) includes an adhesive material (20).
5. The method according to any of claims 1 to 3, wherein the securing material (20; 21) includes an elastic material (21) .

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