EP0402192A1 - Article made of carton or similar material and method for its manufacture - Google Patents

Abstract

The article is of the type comprising at least one part consisting of a blank (1) made of cardboard or similar material, and of a film made of synthetic material (30). It is characterised in that at least one opening (16-17) is made in the cardboard blank (1) but not in the film (30) so that the part of the latter which is situated opposite each opening (16-17) can extend through the latter and be applied and fixed to another part (30) of the article situated against the preceding one. The method for making an article comprising at least one part consisting of a blank made of cardboard (1), or similar material, and of a film made of synthetic material (30) is characterised in that at least one opening (16-17) is made in at least one of the parts (23- 27), in that a thermoplastic film (30) is applied, which covers said opening (16-17), in that the parts (23-27) are placed opposite and in that the film (30) is heated so that it adheres to the other at right angles to the opening (16-17). <IMAGE>

Description

There are many articles made from a material such as cardboard.

Among these articles, we can cite more or less elaborate containers such as trays, boxes, honeycomb trays and grouping supports for bottles of mineral water, soda, beer, etc.

Depending on the applications, the characteristics of the cardboard and the quality of the prints it carries are of a higher or lower level.

On the other hand, the quality of the bonding is an exclusively technical data dictated by the function and this requires or does not require a given resistance.

When it comes, for example, to simply closing a box containing light products, sticking can be weak.

When, on the contrary, bonding provides most of the strength of the article, we are faced with a problem which is not entirely resolved.

In addition, various circumstances can influence the quality of an initial bond: humidity, temperature, etc.

Thus, to avoid that glued parts separate accidentally, one must take into account not only the adhesive used but also the cardboard itself.

Ordinary, compact or corrugated cardboard, or molded cellulose is often made from pulp with short fibers and, as a result, it offers a poor quality surface for bonding because it disintegrates easily. It would be pointless to hope to obtain an energetic collage by choosing an excellent adhesive because the stresses going in the direction of takeoff would have a destructive action not of the adhesive but of the cardboard itself.

It is understood that for certain applications it is therefore necessary to choose both a cardboard of good quality and heavy grammage as well as a strong adhesive.

One such application, cited by way of example, is that of "packs" grouping together several bottles because not only is the content heavy in itself but in addition, the whole is often carried by the cardboard part, by means of two fingers engaged in two holes provided for this purpose, and not supported.

In other cases, the cardboard is suitable for serving as a support for bonding, without necessarily being of very good quality. This is the case, for example, with honeycomb trays intended for the packaging of fruit, eggs and other similar products.

Gluing is also a fundamental operation when the parts to be assembled are a container and lid or seal. Indeed, the content is only protected if the fixing of the cover or lid is of good quality.

The present invention provides a new solution which makes it possible to fix parts, in particular cardboard, between them by providing a high quality result, even if the material used is of poor quality.

To this end, the subject of the invention is an article comprising at least one part composed of a blank of cardboard, or similar material, and a film of synthetic material, characterized in that at least one opening is provided in the cardboard blank but not in the film, so that the fraction of it which is opposite each opening can extend through it and be applied and fixed to another part of the article located against the previous one.

According to other features of this article:
- the other part of the article is made of cardboard or similar material;
- the other part of the article is made of synthetic material;
- the other part of the article is a film applied against a blank of cardboard or similar material;
- the parts of the article located one against the other are composed of a blank of cardboard, or similar material, and of a film of synthetic material and at least one opening is made in the blank of cardboard for each part, so that at least two openings are located face to face when the two parts are located against each other;
- The article is formed from at least one blank cut from a sheet material such as cardboard, or the like, covered at least in part with a thermoplastic film and is kept in shape by fixing one to the other. the other of facing parts, at least one of these parts having at least one opening at the right of which the film of one part adheres to the film of the other part;
- the opening is oblong;
- one of the parts has at least one oblong opening while the other part has at least one non-oblong opening capable of being placed opposite the oblong opening, facing any location thereof;
- The film extends over the entire surface of the blank and above the opening, respectively each opening;
- the film is on only one of the two sides of the blank;
- a film is on each of the two sides of the blank;
- the film is only in each area of the blank which has an opening.

The invention also relates to a method for constituting an article of the above type, characterized in that at least one opening is created in at least one of the parts, that a thermoplastic film is applied which covers said opening, that the parts are placed opposite and that the film is heated so that it adheres to the other at the right of the opening.

According to other characteristics of this process:
- a film is applied over the entire surface of the blank;
- a film is applied only in the areas of the blank which have an opening.

• La figure 1 est une vue en plan d'un flan découpé et imprimé conforme à l'invention, selon un exemple d'application à un conditionnement devant maintenir groupées quatre bouteilles.
• La figure 2 est une vue en plan du même flan que celui de la figure 1 mais par sa face opposée.
• La figure 3 est une vue schématique en perspective du flan de la figure 1 après conformation et fixation de pattes de maintien.
• La figure 4 est une vue schématique partielle en coupe faite selon la lignbe IV-IV de la figure 3 et montrant la fixation de pattes de maintien.
• Les figures 5 à 7 sont deux vues schématiques partielles en coupe illustrant des variantes du mode de réalisation de l'invention selon lequel les deux parties à fixer comprennent un flan de carton et un film en matière synthétique.
• La figure 8 est une vue partielle en plan d'un flan réalisé suivant une variante de l'invention selon laquelle des fractions de film en matière synthétique sont placés seulement en regard d'ouvertures pratiquées dans un flan de carton.
• La figure 9 est une vue schématique partielle en coupe montrant la fixation de pattes pour le maintien en forme d'une barquette obtenue à partie du flan de la figure 8.
• La figure 10 est une vue schématique en perspective d'un conditionnement conforme à l'invention, selon un exemple d'application à un conditionnement pour oeufs, fruits ou analogues et comprenant un plateau alvéolé et une coiffe de fermeture et de protection.
• La figure 11 est une vue schématique partielle en coupe du conditionnement de la figure 10.
• La figure 12 est une vue shématique en perspective d'un conditionnement conforme à l'invention, selon un exemple d'application à une barquette devant recevoir un opercule.
• La figure 13 est une vue schématique en coupe de la barquette de la figure 12 après fixation d'un opercule.
• La figure 14 est une vue schématique partielle d'un mode de réalisation particulier selon lequel la barquette est fermée au moyen d'un opercule en carton associé à un film de matière synthétique.

The invention will be better understood from the detailed description below, made with reference to the accompanying drawing. Of course, the description and the drawing are given only by way of an indicative and nonlimiting example.

• Figure 1 is a plan view of a blank cut and printed according to the invention, according to an example of application to a packaging to keep four bottles grouped.
• Figure 2 is a plan view of the same blank as that of Figure 1 but by its opposite face.
• Figure 3 is a schematic perspective view of the blank of Figure 1 after shaping and fixing of holding tabs.
• Figure 4 is a partial schematic sectional view taken along line IV-IV of Figure 3 and showing the fixing of retaining tabs.
• Figures 5 to 7 are two partial schematic sectional views illustrating variants of the embodiment of the invention according to which the two parts to be fixed comprise a cardboard blank and a film of synthetic material.
• FIG. 8 is a partial plan view of a blank produced according to a variant of the invention according to which fractions of film of synthetic material are placed only opposite openings made in a blank of cardboard.
• FIG. 9 is a partial schematic view in section showing the fixing of lugs for maintaining the shape of a tray obtained from the blank of FIG. 8.
• Figure 10 is a schematic perspective view of a packaging according to the invention, according to an example of application to a packaging for eggs, fruit or the like and comprising a honeycomb tray and a closure cap and protection.
• FIG. 11 is a partial schematic view in section of the packaging of FIG. 10.
• Figure 12 is a schematic perspective view of a packaging according to the invention, according to an example of application to a tray to receive a seal.
• Figure 13 is a schematic sectional view of the container of Figure 12 after fixing a cover.
• Figure 14 is a partial schematic view of a particular embodiment according to which the tray is closed by means of a cardboard cover associated with a film of synthetic material.

Referring to the drawing, it can be seen that an article in accordance with the invention is obtained from a blank 1 cut into the desired shape and optionally coated on one of its faces with printed inscriptions such as a mark 2 and various mentions 3 (composition of the product sold for example).

When cutting the blank 1, openings 10, 11, 12, 13, 14, 15, 16 and 17 are located at places corresponding to the facing portions of the blank intended to be fixed to one another. other.

The example shown is that of packaging intended to group four bottles of the known type according to which the neck of the bottles has a booklet and / or a capsule.

This packaging is known per se and will therefore not be described in detail. It can be seen that the cutting of the blank leaves four orifices 18, 19, 20 and 21, four end tabs 22, 23, 24 and 25 and two flaps 26 and 27.

On the face of the blank 1 opposite to that which receives the printed inscriptions, there is a film 30 of thermoplastic synthetic material which extends over the entire surface of the blank, including over the openings 10 to 17.

On the other hand, the film 30 must not cover the orifices 18 to 21 since they must allow the passage of the bottle necks.

To obtain this blank, we therefore start by creating the openings 10 to 17, then we put the film 30 in place, by extrusion, lamination, coating or other method known per se, then we create the other cutouts, including the orifices 18 to 21. Printing can be done before this last cut.

The blank thus designed is used as follows:

As is known per se, four bottles A are grouped, the blank 1 is put in place so that the necks of the bottles A pass through the orifices 18 to 21, then the blank 1 is conformed by approaching one of the other the end tabs 22 and 25 on the one hand, 23 and 24 on the other hand, which has the effect of reducing the passage section of the orifices 18 to 21 whose edges are under the booklet or under the bottle cap A. In this position, the blank 1 and the bottles A can no longer be separated and it is possible to carry the assembly by engaging two fingers in holes masked by tabs 28 and 29 , provided of course that the material from which the blank 1 has been cut is sufficiently resistant.

It is obviously necessary to vigorously maintain the end tabs 22 to 25 in the position described and the flaps 26 and 27 are used for this purpose.

According to the state of the art, an adhesive is applied to the end tabs 22 to 25, the flaps 26 and 27 are folded down and pressure is applied for a sufficient time for bonding. Optionally, to anchor the adhesive, small slots are created on the tabs 22 to 25.

According to the invention, when approaching the tabs 22 and 25 on the one hand and the tabs 23 and 24 on the other hand, the openings which they carry, respectively 10-13 and 11-12 are separated from the same distance as the openings 14-15 and 16-17 of the flaps 26 and 27. When these are folded over the legs 22 to 25, the openings 10 and 15, 11 and 16, 12 and 17, 13 and 14 are exactly opposite each other.

As the film 30 covers these openings, there are two thicknesses of film 30 facing each other for each opening 10 to 17, these two thicknesses belonging to two parts of the blank 1 having to be fixed one to the other. other: an end tab and a flap.

Is applied to the right of each pair of openings 10-15, 11-16, 12-17 and 13-14 a temperature and a pressure such that it causes both the softening of the two thicknesses of film 30 and their adhesion by merger.

This obtains the energetic fixation of the parts of the blank 1 which ensure its cohesion and allow the use for which it was designed.

It should be emphasized that the process according to the invention has qualities clearly superior to those which a simple bonding provides.

In fact, the adhesion of the two thicknesses of plastic film is independent of the qualities of the cardboard. This can therefore be thinner (lower "grammage") and of lower quality because the presence of short fibers on the surface is no longer an obstacle to bonding.

In addition, the cardboard being hydrophilic, it easily absorbs moisture which has the disadvantage of considerably reducing its cohesion and its resistance, so that even by choosing a cardboard of very good quality and a strong adhesive, the finished article can be destroyed, or seriously weakened, if it is subjected to humidification: rain during outdoor storage or during transport, leaks from neighboring containers during transport or during presentation for sale, etc.

The invention eliminates all these drawbacks since the film 30 is insensitive to moisture.

It is therefore understood that it may be important, for the solidity of the finished article, that the film 30 extends over the entire surface of the blank. However, this is not an obligation, as will be explained below.

In FIG. 4, a hypothesis has been represented according to which the film 30 of the flap 27 is pushed towards the film 30 of the end tab 23 and, even, a deformation of the two thicknesses of film 30 is shown inwards. of the finished article. This results from the arrangement of two opposing parts (known per se) by which pressure and heating were exerted simultaneously on the two thicknesses of the film 30.

It can be seen in FIG. 4 that the two thicknesses of film are only separated by a single thickness of cardboard. This provision comes from the way the article is shaped.

Other configurations are possible.

Thus, in FIG. 5 we see a case where two cardboard parts 40 and 41 coated with a film 30 including over openings 42 and 43 are brought into contact with one another by their coated faces, so that the two thicknesses of film 30 are placed directly against each other.

In FIG. 6, on the contrary, two cardboard parts 50 and 51 coated with a film 30 including over openings 52 and 53 are brought into contact with one another by their uncoated faces, so that the two thicknesses of film 30 are separated by an equal distance the thickness of the two cardboard parts 50 and 51.

We show here the variant according to which the two thicknesses of film 30 are brought closer to each other during the heating and pressure action, so that after welding, the single plastic membrane which results from the local fusion of the two films 30 is located substantially in the middle of the double thickness of cardboard.

In FIG. 7, we see a case where two cardboard parts 60 and 61 are coated with a film 30 but only the part 60 is crossed by an opening 62. As in the case of FIG. 4, the two thicknesses of film 30 are separated by a distance equal to a single thickness of cardboard, that of part 60.

For the welding of the two films 30, pressure and heating are exerted on the film 30 of the part 60 only, it being understood that the part 61 must be maintained by a back pressure.

The fact of providing an opening 62 only on the cardboard part 60, leaves the part 61 intact. It may then be advantageous to design the article so that the part 61 is visible while the part 60 and its opening 62 would be hidden because the aesthetics of the article would be preserved.

Naturally, the invention applies to all kinds of articles, in particular in packaging, and makes it possible to produce possibly compartmentalized trays, boxes, displays etc.

For those of these applications which require a high resistance, it is good to give the openings 10 to 17 an oblong shape because there is thus a large welding surface.

For other less demanding applications, it is of course possible to give the openings different shapes.

This is what was retained for the example of FIGS. 8 and 9.

In FIG. 8, we see a part of a cardboard tray comprising a tab 71 near one of its corners. We assume, of course, that the other corners are similar to the one that is only represented and which we now describe.

In order not to cut the wall of the tray 70, in particular to guarantee its tightness if it is intended to receive wet products, three convergent fold lines 72, 73 and 74 are created, determining two flaps 75 and 76. To erect walls 77 and 78 relative to a central bottom 79, the flaps 75 and 76 are folded in bellows, that is to say that the fold along lines 72 and 74 are made towards the inside of the tray while the fold along line 73 goes outwards. The flaps 75 and 76 are then one against the other. They are pressed against the wall 78 and the tab 71 is folded down as shown in FIG. 9.

Beforehand, according to the process indicated above with reference to FIGS. 1 to 4, an opening 80 has been created on the tab 71 and a corresponding opening 81 on the wall 78.

Here, two differences must be observed compared to the preceding description: on the one hand, the openings 80 and 81 are circular and not oblong. On the other hand, the entire surface of the blank to constitute the tray 70 is not covered with a film.

To ensure the fixing, a thermoplastic film is placed only opposite the openings. In FIG. 8, it can be seen that the tab 71 receives a square film element 90 which covers the opening 80 and that the wall 78 receives another film element 91 which covers the opening 81.

Consequently, the fixing of the two flaps 75 and 76 against the inner face of the wall 78 is carried out as indicated above: by pressing and heating the film elements 90 and 91, as shown in FIG. 9.

The installation of several separate film elements instead of a single film over the entire surface of a blank can be carried out by means which are within the reach of the skilled person. It may be coating, spraying or partial lamination in particular.

It is possible to combine a circular opening and an oblong opening, which makes it possible to produce a fixing in variable position since the part which has the circular opening can be placed differently with respect to the longitudinal axis of the oblong opening, the welding of the films being able to take place either near one of the ends or near the center of the oblong opening.

It is possible to provide a film on one side only, both on the front and on the back, depending on the applications.

The fixing in accordance with the invention makes it possible to avoid the overlaps which are encountered quite often in practice and which have both technical and aesthetic defects, as is well known. Indeed, the invention makes it possible to fix, without any fold, two parts constituting only one superposition and requiring no additional element such as tab or tongue.

Referring now to Figures 10 and 11, we see another embodiment of the invention according to which only one of the parts to be assembled comprises a film of heat-sealable plastic.

To illustrate this embodiment, we have chosen the example of packaging for a plurality of similar objects: eggs, fruits, etc.

This packaging includes a honeycomb tray 100 in molded cellulose, that is to say obtained from a thick paste of this llulose shaped in a mold and dried.

This tray comprises cells 101 determined by reliefs 102. The reliefs 102 in the center have four flats 103 arranged obliquely to the edges of the tray 100. The reliefs located at the edges of the tray 100, only include two flats 103 and a outer flank 104 flat. These are the sides 104 of all the cells which determine the sides of the plate 100. At the four corners of the plate 100, there are reliefs 105 which have only one internal flat 106 and two perpendicular external sides 107.

Until now, trays 100 have been used to group a very large number of objects thanks to the fact that the reliefs 102 constitute pillars which can support without disadvantage the weight of several trays 100 loaded with objects. The trays 100 are therefore not used individually as unit packaging. They are used as dividers horizontal to store and transport large batteries placed in cases and grouping very large quantities of objects that would otherwise be in bulk or packed one by one. In bulk they would be crushed and damaged; packed one by one they would come back at an excessive price.

This packaging method is therefore reserved for transport and wholesale storage. For the debit by retail sale, the trays 100 are removed one by one and then the objects are extracted in small quantities to place them in small containers: boxes, if appropriate, honeycombed.

But there is a need to retail quantities of objects corresponding to the capacity of a tray.

The present invention applies particularly well to the resolution of this problem and, for this, in accordance with the invention, a plate 100 of any known type, that is to say made of compressed cellulose, of synthetic material or other and we associate it with a closure and protection cap.

The cover 110 of FIG. 10 consists of a cardboard blank 111 cut and grooved to present a central part 112, two side panels 113 and two end panels 114 provided with side tabs 115.

The central part 112 is cut out from several openings 116. The side panels 113 and the end panels 114 are cut out from openings 117.

Thus cut and grooved, the blank 110 receives over its entire outer surface a hot-melt film 120 which adheres to the entire remaining surface of the blank 110 and closes all the openings 116 and 117 by covering them.

To condition objects B such as eggs, each of these is placed in a cell 101 and then a cap 110 is placed above the tray 100 garnished. The legs 115 are folded back as suggested in FIG. 10, then the panels 114 and 113 are folded down and, finally, a suitably heated purlin C is applied to the film 120, in line with each opening 117 (FIG. 11).

The softening of the film 120 causes it to stick to the cardboard of the tray 100 and, consequently, ensures the fixing of the cap 110 on the tray 100.

Note that when the cap 110 is placed, the panels 113 and 114 are placed parallel to the sides 104 and 107, against them, and the film 120 is fixed to the sides 104. These are resistant and it is possible apply the purlins according to the pressure most favorable for fixing the film 120.

The openings 117 have an extent which is calculated as a function of the degree of adhesion of the film 120 and of the material used to make the plate 100. It is obvious that the larger the extent of the openings 117, the more the fixing of the cap is solid. However, the manipulations of the assembly 100-110 are not very restrictive because there is little effort directed towards the detachment of the cap. Consequently, it is unnecessary to have many openings 117 and / or to give them a large extent. It is also necessary to allow the user who will have to take off the cover 110 to access the objects B, to obtain the opening of the packaging without excessive effort, especially since the objects B are fragile or delicate.

It is advantageous to choose a transparent film 120 for two reasons: first, this makes it possible to print the blank 111 before covering it with the film 120, the impressions appearing through the film 120. Then, the openings 116 allow the user to observe the objects 120, for example at the time of purchase, without opening the packaging. We are thus assured that in self-service stores, unscrupulous buyers will not deteriorate the packaging.

Referring now to Figures 12 and 13, there is shown another embodiment of the invention according to which a film is applied to another film associated with a cardboard part.

The example used to illustrate this embodiment is that of a tray 200 which is obtained, as is known per se, by cutting and creasing a cardboard blank 201 which has a bottom 202, side walls 203 and frontal 204 as well as corner walls 205, all the walls 203, 204 and 205 ending in a free edge.

The blank erected in volume, as shown in FIG. 12, receives by thermoforming a film 210 which covers the bottom 202 and all the walls 203, 204 and 205. In addition, it forms a plane peripheral rim 211 intended to receive a cover having a film fixed by heat sealing.

A tray thus produced has the advantages of rigidity, solidity of the cardboard and the advantages of sealing and neutrality of the synthetic material constituting the film 210.

According to the invention, openings 206 on all of its faces 203, 204 and 205 are housed in the cardboard blank 201 before the film 210 is put in place. After thermoforming of the film, it therefore appears outside. of the tray according to the extent of the openings 206.

A cover according to the invention has a very particular structure because it is not only applied flat on the flange 211 as is currently the case.

Referring to FIG. 13, it can be seen that a cover 300 according to the invention is first heat sealed on the top of the rim 211, after filling the tray 200 according to any known means: under vacuum, with gas supply neutral, etc.

The cover has an extent significantly greater than that which is limited by the external contour of the flange 211 and, after heat-sealing, the margins which extend beyond the flange 211 are folded down so that they apply to the external face in cardboard from the walls 203, 204 and 205 to a level n situated lower than the lower edge of the openings 206 which is located at a level N.

A purlin D is then applied to the right of each opening 206 in order to apply the folded parts of the cover 300 against the film 210 which appears through the openings 206.

FIG. 13 shows that the heat sealing of the cover 300 and its fixing below the level of the rim 211, in line with the openings 206, creates for each wall 203 and 204, taut portions 301 which increase the safety of the sealing waterproof.

Indeed, it is known that the lids which are only fixed on the usual flange of small width, are sometimes poorly secured, which causes leaks when the tray contains flowing products. Sometimes also, the handling of the trays runs the risk that a lid even if well fixed is torn off in part, in particular because of a small tab which is provided near a corner of the lid for its removal. .

Here, on the contrary, these two risks are eliminated by the double fixing of the cover: heat sealing on the rim 211 and heat sealing against the walls 203-204.

Tests have shown that thanks to the invention, it is possible to provide edges 211 having three millimeters wide instead of five, which not only represents a saving in material but, above all, provides a better appearance to the entire packaging. .

For clarity of description, the stretched parts 301 are shown rectilinear and extending directly from the free outer edges of the flange 211 to the openings 206. One could also carry out the heat sealing so that these stretched parts 301 have a upper fraction pressed against the walls 203-204 above the openings 206 and may even be enveloping the rim from below. This is a choice within the reach of those skilled in the art, the important thing being that the cover 300 is fixed beyond and below the rim 211.

To access the contents of the tray, cut one of the stretched parts 301 above the corresponding openings 206 and thus release a certain surface which forms a very effective traction element because it offers the fingers of the user. a much larger and sturdier grip than the small tab currently in use.

Here again, it is advantageous to use a transparent film to form the cover 300, in order to reveal the contents of the tray and / or of the impressions applied to the cardboard blank 201.

However, it may be that we prefer to use the large central surface of the tray to print a decoration or useful information such as composition of content and method of preparation for food products. In this case, a printed cardboard panel 302 is associated with the cover 300.

In FIG. 14, a variant is seen according to which the entire cover 300 is formed by a cardboard panel 303 and a heat-sealable film 304. The tray 200, here again, is formed by a blank of cardboard 201 coated, by thermoforming , of a heat-sealable film 210 which has a peripheral rim 211 without cardboard.

The installation of the cover 300 is done as previously: heat sealing on the flange 211 then folding down but, here, the presence of the cardboard panel 302 requires to provide cutouts at the four corners, as is well known in itself, if you want to fold the lid on the four walls of the tray. If we just fold it down on two opposite walls, the blank forming the cover is simply quadrangular.

In addition, to facilitate the folding down of the panel 302, creasing lines are provided along which the cardboard easily folds, as is well known in itself.

The choice between the solution of FIG. 13 and the solution of FIG. 14 according to its two variants (drawdown on two or on four walls) depends on the aim sought and on the constraints and characteristics of each case.

It should be noted that in comparison with the very good prints obtained on the cardboard, the rim 211 made of synthetic material observed from the bottom up, is not very flattering. Thanks to the folding of the cover 300, it is the folded panel 302 that we see because it hides the underside of the rim 211 and offers the observation a larger printed surface while giving the entire packaging a original and attractive form.

It emerges from the above description that, thanks to the invention, it is possible to use the adhesion faculty of a film of synthetic material to fix the part which carries it to another part, whether this is only in cardboard, only made of synthetic material or formed by the combination of these two materials.

The foregoing description essentially refers to cardboard because the invention applies particularly well to it, but the invention applies to other materials which are presented in sheets or sheets and which are not adhesive in themselves: fabrics, non-woven materials, synthetic materials, wood etc.

Claims (14)

1- Article comprising at least one part composed of a cardboard blank, or similar material, and of a plastic film, characterized in that at least one opening is made in the cardboard blank but not in the film , so that the fraction of it which is opposite each opening can extend through it and be applied and fixed to another part of the article located against the previous one. 2- Article according to claim 1, characterized in that the other part of the article is made of cardboard or similar material. 3- Article according to claim 1, characterized in that the other part of the article is made of synthetic material. 4- Article according to claim 1, characterized in that the other part of the article is a film applied against a blank of cardboard or similar material. 5- Article according to claim 1, characterized in that the parts of the article located one against the other are composed of a blank of cardboard, or similar material, and a film of synthetic material and an opening at least is provided in the cardboard blank of each part, so that at least two openings are located face to face when the two parts are located against each other. 6- Article according to claim 1, characterized in that it is formed from at least one blank cut from a sheet material such as cardboard, or similar material, covered at least in part with a thermoplastic film and is kept in shape by fixing to each other of facing parts, at least one of these parts having at least one opening at the right of which the film of one part adheres to the film of the other part . 7- Article according to claim 1, characterized in that the opening is oblong. 8- Article according to claim 6, characterized in that one of the parts has at least one oblong opening while the other part has at least one non-oblong opening capable of being placed opposite the oblong opening, face anywhere in the latter. 9- Article according to claim 1, characterized in that the film extends over the entire surface of the blank and over the opening, respectively each opening. 10- Article according to claim 1, characterized in that the film is on only one of the two faces of the blank. 11- Article according to claim 1, characterized in that the film is only in each area of the blank which has an opening. 12- Method for constituting an article comprising at least a part composed of a blank of cardboard, or similar material, and a film of synthetic material, characterized in that at least one opening is created in at least the one of the parts, that one applies a thermoplastic film which covers said opening, that one puts the parts opposite and that one heats the film so that it adheres to the other at the right of the opening. 13- A method according to claim 12, characterized in that a film is applied over the entire surface of the blank. 14- A method according to claim 12, characterized in that a film is applied only in the areas of the blank which have an opening.

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