EP1836110B1 - Plastic packaging and production and packaging method - Google Patents

Description

The invention relates to a plastic package, its manufacturing method and a manufacturing device. It is particularly suited to the field of food packaging for parallelepipedic, prismatic or cylindrical packaging, and thus also relates to a method of packaging a food product.

A first solution of the prior art concerns an aluminum packaging as disclosed by the FR2012286 . Its manufacturing process includes the folding and joining of several aluminum sheets. Aluminum is a product whose obtaining and recycling require a great expenditure of energy and it is desirable not to use it.

For this, the document EP0803439 discloses a polypropylene package made by joining three plastic sheets, one of which is shaped around a mandrel. The disadvantage of this manufacturing process is its complexity because it requires the cutting and joining of three sheets and a construction around a mandrel.

To solve the disadvantages of the previous solution, another method of manufacturing a plastic package is described in the document WO2004 / 052753 , which rests on the cutout of a main sheet, which represents a large surface of the finished package and comprises a projecting portion defining an opening tab, on which a cover is added. The disadvantage of this method stems from the fact that the complex shape of the proposed sheet leads to significant material drops when it is cut from a rectangular plastic film. In addition, since the film is coated with an adhesive to promote hot gluing on the lid and to obtain the tightness of the package, there is a risk of obtaining the bonding of the opening tab on the cover since it is also coated with this glue and that the entire process is based on heating and possibly hot food content during its packaging, which makes it difficult to use.

A fourth method of manufacturing a package is known to DE3233670 .

A general object of the present invention is to provide a package and its manufacturing method which have the advantages of the prior art without the disadvantages.

More specifically, a first object of the invention is to provide a packaging and its manufacturing process simpler, economic and ecological.

1. a) -découpage de feuillets dans un film sur lequel les feuillets sont disposés en quinconce de sorte que ce découpage génère peu ou pas de chute ;
2. b) pliage d'un feuillet pour former une coquille;
3. c) ajout d'un couvercle;
4. d) pliage de rabats sur le couvercle, un rabat comportant une partie sensiblement triangulaire en saillie formant une languette d'ouverture.

A second object of the invention is to provide a method of manufacturing a packaging adapted to the field of food packaging.
The invention is based on a method of manufacturing a package, characterized in that it comprises the following steps:

1. a) -cutting leaflets in a film on which the leaflets are staggered so that this cutting generates little or no fall;
2. b) folding a sheet to form a shell;
3. c) adding a lid;
4. d) folding flaps on the lid, a flap having a substantially triangular protruding portion forming an opening tab.

Advantageously, the film is a plastic film, one side of which is coated with a heat-sealable material.

Step a) may further comprise a step of transporting, reversing and welding a triangular fall of the film on the projecting triangular portion of corresponding size, bringing into contact the two heat-sealable coated surfaces of the two parts, for form the opening tab.

Steps b) and d) may include hot bends.

The method may include a step of cutting a thin tear strip and a step of bonding the tear strip to the sheet so that it extends from the end of the opening tab to a length important leaflet, and / or a step of making pre-cuts on the opening tab.

The invention also relates to a package comprising a main sheet occupying its largest area, comprising a cover, flaps of the leaf folded on the cover, characterized in that one of the flaps comprises a substantially triangular projecting portion, the oblique edge of which delimiting the triangular portion is symmetrical about its center so that it can place several sheets of the same form staggered on the same film.

The angular portions of the sheet, opposite the projecting triangular portion, have a rectangular shape whose angle is truncated, defining a triangle of dimension approximately equal to half of the opening tongue.

Alternatively, the package comprises a main sheet having a rectangular central portion, four side portions, one of which is extended by the substantially projecting triangular portion, four truncated rectangular corner portions, the sheet being folded to form a parallelepiped package rectangle.

The main sheet of the package may be of plastic material, for example polypropylene.

• La figure 1 a représente une vue d'un feuillet plastique dans une étape au début du procédé de fabrication de l'emballage, selon un mode d'exécution de l'invention ;
• la figure 1b représente plusieurs feuillets plastique sur un même film avant leur découpage ;
• la figure 2 représente une vue schématique d'une première étape du procédé de fabrication de l'emballage selon un mode d'exécution de l'invention ;
• la figure 3 représente la coquille obtenue après cette première étape ;
• la figure 4 représente une vue schématique d'une seconde étape du procédé de fabrication de l'emballage selon un mode d'exécution de l'invention ;
• la figure 5 représente une vue schématique d'une troisième étape du procédé de fabrication de l'emballage selon un mode d'exécution de l'invention ;
• la figure 6 représente une vue schématique d'une quatrième étape du procédé de fabrication de l'emballage selon un mode d'exécution de l'invention ;
• la figure 7 représente une vue schématique d'une cinquième étape du procédé de fabrication de l'emballage selon un mode d'exécution de l'invention ;
• la figure 8 représente une vue schématique d'une sixième étape du procédé de fabrication de l'emballage selon un mode d'exécution de l'invention ;
• la figure 9 représente une vue schématique de la fin du procédé de fabrication de l'emballage selon un mode d'exécution de l'invention ;
• la figure 10 représente une vue de l'emballage fini.

This object, features and advantages of the present invention will be set forth in detail in the following description of a particular embodiment made in a non-limiting manner in relation to the attached figures among which:

• The figure 1 a represents a view of a plastic sheet in a step at the beginning of the packaging manufacturing process, according to an embodiment of the invention;
• the figure 1b represents several plastic sheets on the same film before their cutting;
• the figure 2 is a schematic view of a first step of the method of manufacturing the package according to one embodiment of the invention;
• the figure 3 represents the shell obtained after this first step;
• the figure 4 is a schematic view of a second step of the method of manufacturing the package according to one embodiment of the invention;
• the figure 5 is a schematic view of a third step of the method of manufacturing the package according to one embodiment of the invention;
• the figure 6 is a schematic view of a fourth step of the method of manufacturing the package according to one embodiment of the invention;
• the figure 7 is a schematic view of a fifth step of the method of manufacturing the package according to one embodiment of the invention;
• the figure 8 is a schematic view of a sixth step of the method of manufacturing the package according to one embodiment of the invention;
• the figure 9 is a schematic view of the end of the packaging manufacturing method according to one embodiment of the invention;
• the figure 10 represents a view of the finished package.

The embodiment shown represents an application in the field of food packaging, for the packaging of a cheese in a rectangular parallelepiped shaped packaging.

The method of manufacturing the package is based on a plastic sheet 1, for example polypropylene, illustrated on the figure 1a , one side, which will correspond to the inner surface of the manufactured packaging is coated with a heat-sealable material. This sheet comprises a central zone 2, four lateral bands 3, one of which is extended by a projecting triangular tip 4 which is intended to form a tongue to facilitate the opening of the package. The sheet 1 finally comprises four angular zones or ears 5 which will be folded along a fold line 6. Two tear strips 7 extend from the triangular point 4 to the opposite lateral strip, along the edges of the central portion 2.

The sheets 1 are cut from a rectangular film 8 illustrated in figure 1 b. Their shape is such that they are distributed in staggered rows on the film 8, forming only a small triangular element 9 as a drop after the cutting of the film 8. For this, the oblique edge 4a, going from the point A to the point B of the sheet 1, drawing the contour of an angle 5 and the tip 4 of the sheet 1, also defines this sheet 1 with respect to another sheet placed in staggered rows on the film 8. For this, this edge 4a has a symmetrical shape around from its central point O; Thus, the point B is at the end of the tip of a sheet 1 and the point A at the end of the tip of the sheet placed in a quincunx and the two sheets have exactly the same shape.

After this cutting of the film 8, the triangular element 9 is transported, turned over and glued to the projecting tip 4 of the sheet 1, this step can be implemented using a device which will be described later, of so as to bring into contact the two heat-sealable material-coated surfaces of the two triangular elements 4 and 9 and to obtain their soldering after heating. A resistant opening tongue 10 is thus obtained by the union of the two elements 4 and 9. The triangular element 9, obtained by truncating the angular portions 5 of the sheets 1 opposite to the projecting point 4, is provided with a dimension corresponding to that of the projecting tip 4 of the sheet 1. The tearing primers 11 are also provided at this opening tab 10. The preparation of the sheet 1 thus formed does not generate any plastic material drop.

Then, in a first manufacturing step represented diagrammatically in figure 2 , the sheet 1 is lowered through a not shown training corridor, which progressively folds the ears 5 along their fold line 6 through helical parts of the formation corridor. The latter further causes the folding of the side portions 3. At the exit of the corridor, the folded sheet 1 is placed in a bucket 12 by a punch 13. During the entire descent phase, the sheet 1 is also heated. The heat makes it possible to obtain a definitive folding of the plastic material of the sheet 1, by modifying its memory, to form a shell 15 illustrated in FIG. figure 3 in the bucket 12. The bottom 14 of this bucket is movable by a piston system and is fixed so as to form a bucket 12 of depth equal to the width of the flaps 3 of the sheet 1.

The second step, illustrated in figure 4 , corresponds to the filling of the shell 15 with a food substance 11, cheese, for example. This substance does not fill the entire height of the shell.

The third step consists in laying a cover 16 of plastic surface corresponding to that of the central zone 2 of the sheet 1, which forms the base of the shell 15.

In a fourth step illustrated in figure 6 , the bottom 14 of the bucket 12 is raised so that the portion 17 of the four side walls 3 of the shell above the cover 16 protrudes from the upper surface of the bucket 12. It is then folded two of these parts 17 placed on opposite sides, which forms flaps 17, with two clamps 18 on each side and a counter piece 19 placed on the cover 16 so as not to crush the contents 11 of the packaging manufacturing. During this step, the four corners of the flaps 17 are folded, heated and squeezed to remain in place by this hot gluing.

The figure 7 illustrates a fifth step by which a hot reel 21 will fold down the last two opposite side surfaces 17 by pressing against a counterpart 20 disposed on the lid 16. At the end of this step, the four flaps 17 of the four lateral sides 3 are folded over the cover 16. This step may be repeated for a second times to ensure success and prevent one or more flaps from unfolding.

The figure 8 illustrates a last step by which a hot press 22 presses the entire upper surface of the package to ensure the welding of the entire surface of the flaps 17 on the cover 16 and ensure the tightness of the package. During this step, the bottom 14 of the bucket 12 is lowered so that the package is fully depressed in the bucket 12 so that the press 22 remains retained by the upper lateral surface of the bucket 12 and can penetrate only a few millimeters, avoiding the crushing of the packaging. Only the tongue 10 of the triangular tip of one of the flaps 17 is not glued to the cover 16 because it does not include a heat-sealable coating on its surface. It can thus be easily manually grasped and serves as the opening tab of the package.

Finally, as represented in figure 9 , the finished package 24, represented in figure 10 , has left the bucket 12 by the piston 14 of the bottom of the bucket which goes up completely out of the bucket, so that it is guided by a transport means 23 and stored with the other finished products.

Claims (10)

1. Method of producing a packaging, characterised in that it comprises the following steps:

   a) cutting sheets (1) comprising a lateral strip (3) extended by a protruding substantially triangular point (4) from a film (8) on which the sheets (1) are disposed in alternating rows so that the cutting process generates little or no offcut;

   b) folding a sheet (1) to form a shell (15);

   c) adding a cover (16);

   d) folding flaps (17) onto the cover (16), the flap (17) comprising the protruding substantially triangular part (4) forming an opening tab (10).
2. Method of producing a packaging as claimed in claim 1, characterised in that the film (8) is a plastic film, one face of which is coated with a heat-sealable material.
3. Method of producing a packaging as claimed in claim 2, characterised in that step a) further comprises a step of conveying, turning and sealing a triangular offcut (9) of the film (8) onto the protruding, triangular part (4) of corresponding size by placing the two faces of heat-sealable material of the two parts (4, 9) in contact to form the opening tab (10).
4. Method of producing a packaging as claimed in claim 2 or 3, characterised in that steps b) and d) comprise hot folding operations.
5. Method of producing a packaging as claimed in one of the preceding claims, characterised in that it comprises a step of cutting a fine tear-off strip (7) and a step of gluing this tear-off strip onto the sheet (1) so that it extends from the end of the opening tab (10) across a significant length of the sheet (1) and/or a step comprising making pre-cuts (11) on the opening tab (10).
6. Method of producing a packaging as claimed in one of the preceding claims, characterised in that the oblique edge (4a) outlining the contour of the protruding triangular point (4) of each sheet (1) also bounds said sheet (1) relative to another sheet positioned in an alternating row on the film (8), said edge (4a) having a symmetrical shape around its central point (0).
7. Packaging comprising a main plastic sheet (1) occupying its biggest surface, comprising a cover (16), flaps (17) of the sheet (1) folded onto the cover (16), characterised in that one of the flaps (17) comprises a protruding substantially triangular part (10), the oblique edge (4a) of which bounding the triangular part is symmetrical around its centre (0) to enable several sheets (1) of the same shape to be positioned in alternating rows on a same film (8).
8. Packaging as claimed in claim 7, characterised in that the angular parts (5) of the sheet (1) opposite the protruding triangular part (4) have a rectangular shape, one angle of which is truncated, defining a triangle approximately equal in size to half of the opening tab (10).
9. Packaging as claimed in one of claims 7 or 8, characterised in that the sheet (1) has a rectangular central part (2), four side parts (3), one of which is extended by the protruding substantially triangular part (4), four truncated, right angled parts (5), the sheet (1) being folded to form a rectangular, parallelepipedic packaging.
10. Packaging as claimed in one of claims 7 to 9, characterised in that the sheet (1) is made from a plastic material.

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