ES2312739T3 - PACK WITH PERFORABLE COVER. - Google Patents

Abstract

The packaging (10), especially for foodstuffs, has a tub (12) with an upper opening (16) surrounded by a flat rim (20). The opening is covered and sealed by a polymer film (14), secured to the rim by a peripheral weld (22). The sealing film carries a weakened line (24) for a circular section (18) to be pulled clear by a tab (26). The peripheral weld has a stronger hold than the resistance of the weakened film line.

Description

Container with perforable lid.

The present invention relates to a container according to the preamble of claim 1.

Today, numerous food products are conditioned in trays or glasses initially sealed by means of a top. These products can be solid, such as rice, pasta, sauce dishes It can also be semi-liquid products, such as soups or desserts or even liquids, such as drinks Refreshing or yogurt

In known containers, the lid is formed by a polymer film welded on the periphery of the opening of access. To access the contents of the container, the lid must trim or tear. In particular, it is known, to allow tear off the cover by breaking the peripheral weld, provide a strip over the edge of the opening, being able to hold this protruding strip manually by the user to exercise a traction on the lid.

This strip that extends the lid beyond the access opening is sometimes difficult to hold, and the opening of the container for the breakage of peripheral welding is often difficult to get. In particular, a controlled welding with a breaking strength of the weld sufficiently high to effectively protect the products to be packaged and insufficient enough to allow a break without the user have to make an effort too important.

Document US-A-3,550,835 describes, in view of Figure 1, a package according to the preamble of the claim.
tion 1.

The document GB-A-2,156,660 describes a package of another type since it is not welded and not sealed.

Thus, these containers do not provide satisfaction full and, in particular, are difficult to open.

The object of the invention is to propose a container whose opening is easier.

For this purpose, the invention aims at a container according to claim 1.

According to particular embodiments, the invention comprises one or more of the characteristics of the dependent claims.

The invention will be better understood from the reading of the attached description, which is given only by way of example and will be done with reference to the drawings, in which:

- Figure 1 is a perspective view of a first embodiment of a container before opening;

- Figures 2, 3, 4 and 5 are identical views of those of figure 1 in successive phases of the opening of the container;

- Figure 6 is a perspective view of another embodiment of a package according to the invention before the opening;

- Figure 7 is a view identical to that of the Figure 6 of the container, after opening; Y

- Figure 8 is a perspective view of another embodiment of a package according to the invention.

A container 10 is shown in Figure 1 for the conditioning of a solid cooked dish or of solid food products. This package is specially adapted for a product that undergoes a sterilization treatment or pasteurization. It is intended to be heated, in particular, in a microwave oven. The container can also be used for conditioning of liquid or semi-liquid food products or non-food products, such as cosmetic products, shampoos, glues or mechanical elements such as screws.

This package consists of a tray generally circular 12 and by a flexible cover 14 for closing a access passage or opening 16 inside the tray 12.

The tray consists of a film of thermoforming polymer It is relatively rigid and in particular self-supporting, so that it retains its shape although this container whether or not it is full of content, such as a product food Tray 12 is, for example, constituted by a outer support layer of suitable material, for example of polyvinyl chloride (PVC), coated on its surface interior with a weldable layer, for example polyethylene (PE). The tray, alternatively, is formed by a polymer thermoforming, such as amorphous polyester (APET), polypropylene (PP), polystyrene (PS), or an amorphous polyester complex (APET) / polyethylene (PE).

The tray defines a receptacle 18 confined especially its perimeter of an edge 20 that delimits a surface welding plane of the cover 14 according to a peripheral welding 22

The cover 14 consists of a film Flexible polymer formed by one or several overlapping layers. The cover 14 has an identical shape to the outer edge perimeter peripheral of the tray and, more exactly, an identical form to that of welding 22. Thus, no outer fastening strip is not extend the cover outwards beyond weld 22 in the prolongation of a weakening line.

Initially, the lid remains on the edge 20 through the access opening 16. In particular, it keeps the lid on the divergence of food products contained in the package, so that a space is interposed free 23 (Figure 4) filled with air or any other gas between the lid and food products contained in the package and that they rest on the bottom of the tray.

The gas contained in the free space 23 can be at atmospheric pressure, at a higher pressure or at a lower pressure In the latter case, a vacuum is created the more or less advanced in the packaging after sealing.

According to the invention, the cover 14 comprises, outside of peripheral welding 22, in the coverage region of the access opening 16, a line of weakening 24 of the lid. This line of weakening 24 does not cross the thickness of the lid. The weakening and welding line 22 of the lid on the container are such that the breaking strength of the lid according to the weakening line it is less than the resistance to weld break after application of a pressure on the lid

Preferably, the breaking strength of the tension cover on each side of the weakening line is includes between 1 N / 15 mm and 70 N / 15 mm, and preferably between 2 N / 15 mm and 25 N / 15 mm.

In the embodiment of Figure 1, the weakening line 24 delimits a closed contour and is completely includes its layout in the coverage region of the access opening 16. The closed contour delimits a profile that generally corresponds to the edge profile 20 that borders the passage 16.

More specifically, in the embodiment represented, the weakening line 24 delimits a profile generally circular and locally has a tongue 26 that stands out in relation to the general layout of the line of weakening outward.

This tab has a profile generally concave of substantially constant curvature. Has some dimensions that generally correspond to the dimensions of the End of a finger of a human being. So, this tab has a width included between 2 cm and 5 cm and a length included also between 2 cm and 5 cm.

The weakening line 24 that delimits the tab presents advantageous but not necessarily, at least an unrepresented angular tip that forms an adapted acute angle to favor the rupture of the lid.

The cover 14 comprises a visible mark of definition of the position of the weakening line 24. In the embodiment illustrated in figure 1, this mark is constituted by a dashed black line printed on the top.

The weakening line 24 is made by treatment of the film constituting the lid 14.

According to a first embodiment, the line of weakening 24 is performed by applying a high energy radiation, such as a laser, by application of a laser beam according to the line of the weakening line 24, before that cover 14 is placed on the tray. The treatment by means of high energy radiation it is carried out on one or several films of the cover 14 when it comprises several.

According to another embodiment, the line of weakening is formed by a mechanical weakening of the cover that extends according to the line of the weakening line 24. This mechanical treatment is performed on one or several cover films when it comprises several.

According to a first example, a microporous weakening according to a band of reduced width for at least partially form the line of weakening 24. This microporous band of a film is obtained for example by the passage of the cover film between two rollers, one of the which becomes abrasive according to the layout of the line weakening This treatment is described, for example, in the document FR-2,717,449.

According to a second example, the weakening mechanical is formed by a notch the thickness of one or several cover films when it comprises more than one film. These notches are made using an array of elements. sharp, compressing the cover between this matrix and a support, as he knows himself.

According to another example, the weakening line is obtained through a line of non-through microperforations to through the lid, passing these microperforations through a or several films when the cover comprises several.

According to a particular embodiment, the weakening of the lid according to the weakening line is variable depending on the longitudinal position of this line of weakening For example, weakening is more important in the region of the edge of the tongue 26 which on the perimeter generally circular that borders peripheral welding.

These weakening differences are obtained for example by the local combination of several treatments of weakening on one or several films that constitute the lid, or by the application of a weakening treatment more or less deep or more or less dense depending on the regions of the line weakening 24. This treatment the more or less dense or more or Shallower is done especially by submission of the High energy radiation film.

According to a first embodiment, the cover 14 It is single layer and is formed by a base film of polymer or paper. Thus, the cover 14 is a single-cover material. To ensure its connection on the edge of the tray, The polymer film or paper that forms the lid is covered advantageously on its inner surface of a material of sealing placed, for example, by extrusion, coating, coextrusion or coating after ink application of Printing on the base film.

The base film is preferably formed at from a bioriented polymer film that can be coextruded It can also be a movie mono-oriented or non-oriented obtained by coextrusion This film is formed, for example, from polypropylene (OPP), polyester (OPET), or polyvinylchloride (PVC) The thickness of the base film is usually included between 5 and 500 microns, and preferably between 15 microns and 150 microns

The sealing material is chosen to be compatible with the material that constitutes the tray to allow a weld Typically, the thickness of the sealing material is included between 10 and 40 microns, including the amount of reservoir of sealing material between 1 and 12 g / m2.

In this case, the weakening is formed in the base film.

According to a second embodiment, the cover 14 It is formed by two complex films. So, the lid comprises a base film formed by polymer or paper associated according to your face turned towards the tray from a Polymer sealing film compatible with the material of the tray to allow welding.

The base film and the sealing film are linked together by lamination with the help of a glue or resin extrusion.

The base film is advantageously formed by a bioriented polymer film. However, this movie can also be a cast movie ("cast"). He polymer forming the base film is preferably of polyester (PET), polyamide (OPA) or polypropylene (OPP).

The sealing film is formed by for example, from polyethylene (PE), possibly mixed or coextruded with other polymers. The sealing film, in a alternative, it is formed from polypropylene (PP), preferably cast ("cast"), homopolymer type or copolymer with ethyl vinyl acetate (EVA).

According to another alternative, the sealing film It consists of amorphous or copolyester polyester (PETG).

When the lid is formed by two films complex, the film turned towards the tray receives advantageously on its face in contact with the tray a varnish of sealed, as in the case of a single material lid.

In this embodiment, where the lid is form by means of two films, the weakening is carried out on the outer layer and eventually over a part of the thickness of the layer internal According to a particular embodiment, the film External is weakened by high radiation treatment energy after the inner film is weakened by a mechanical treatment, such as a microporous weakening or reverse. The same mechanical or radiation treatment provides high energy, alternatively, on the two films.

In an alternative, the cover 14 is formed from of a complex two-layer film formed for example from Polyester (PET) / Polypropylene (PP) film aluminum / polyester (PET), aluminum / polypropylene film oriented (OPP) or paper / polypropylene (PP) layer.

Polyethylene films are complex advantageously by coextrusion with a low thickness.

According to one embodiment, the cover comprises three movies, whose three end movies are such as the mentioned above in a cover formed by two films, interposing an intermediate film between the two films of extremes

This intermediate film is formed by example, from an aluminum sheet of 6 to 100 microns and preferably from 7 to 38 microns. This sheet is hammered Aluminum overheats or hardens.

Thus, the lid is formed for example of polyester (PET) / aluminum / cast polypropylene (PPC) or polyester (PET) / aluminum
nio / polyethylene (PE) or even oriented polyamide (OPA) / aluminum / polypropylene (OPA) / aluminum / cast polypropylene (PPC) or oriented polyamide (OPA) / aluminum / cast polyethylene (PEC).

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Alternatively, the intermediate film is a bioriented film, for example a polyamide film oriented, in particular, of a polyester structure (PET) / polyamide (OPA) / polypropylene (PP) and polyester (PET) / polyamide  (OPA) / polyethylene (PE).

When the cover comprises three films, the intermediate film is advantageously weakened by treatment with high energy radiation according to the line of weakening

According to an alternative, the cover is formed by three films and is composed, for example, of polyester (PET) / poly-
Lipropylene (PP) / Polyester (PET).

This container is opened as follows.

After the container is placed on a flat surface from the bottom of the tray, the user inserts the tongue 26 of the lid inside the container supporting its finger, as shown in figure 2. The contents of the container the cover is not immediately present below, so that it can deform inward, causing the onset of its rupture according to the weakening line 24 without the lid entering in contact with the product contained in the package and relying on the bottom of the tray.

The resistance to rupture of the lid is more low following the line of weakening that resistance to welding break, breaking the film in the vicinity of the user's finger. In particular, the curvature of the tongue is relatively important, breaking the lid according to The contour of this tongue.

After the initial drilling of the lid by finger support, a characteristic noise like a "pop" is audible to the user due to the passage of gas contained in the tray through the lid broken when the pressure of this gas is higher than atmospheric pressure.

Also, a characteristic noise is also audible to the user after the initial break of the lid after the initial pressure in the container is lower than the atmospheric pressure. This noise results from the passage of air from the outside of the container inwards through the broken lid.

If necessary, the container is placed in a microwave oven after the lid only breaks over the perimeter of the tongue. Under the action of radiation in the oven microwave, the products contained in the package are heated and produces a release of gas through the opening formed to the tongue level 26. Moreover, this tongue overheats and tends to bend outward from the container, as appreciate in figure 3.

After the container leaves the oven, the user easily hold the deformed tongue and pull on the part of the cover delimited by the weakening line 24. Thus, the lid breaks progressively along this line of weakening, as seen in figure 4 until the central range of the lid is completely moved, as shown in figure 5, thus allowing access to the food product contained in the container.

Alternatively, the container is placed in a Microwave oven before the lid does not break. Radiation of microwaves cause heating of the products contained in the container, so that the pressure in it increases. Under the action of the pressure in the container, the lid expands outwards, until it breaks along the line of weakening, in particular on the contour of the tongue 26. After the removed from the microwave oven, the separate part of the lid is torn and completely removed from the rest of the container, as can be seen in figure 5.

In figures 6 and 7 another mode is represented of realization of a container according to the invention.

In this embodiment, the elements identical or similar to those of the first embodiment are designated by the same reference numbers.

Here, tray 12 is replaced by a glass designated by the same reference number, the vessel being deeper than the tray and that is likely to receive a liquid.

In addition, the weakening line, indicated 124, defined on the surface of the lid 14 forms a line transverse that extends into the coverage region of the opening of access between two different points of peripheral welding 16. More specifically, this line of weakening 124 connects two opposite points of the perimeter of the access opening. Presents a general arched shape that presents, in its middle part, a tongue 126 in a manner comparable to tongue 26 of the mode of previous embodiment.

In this embodiment, the tongue 126 has, according to its outline, an angular tip 128 that facilitates the initiation of the rupture of the lid according to the line of weakening

After sinking the lid, for example by resting a finger on the surface of the tongue 126, the cover it breaks according to tip 128. The break propagates according to the contour of the tongue 126 on each side thereof. Then the operator holds the tongue 126 and pulls the lid part separated, as shown in figure 7. Thus, the complete rupture of the cover according to the weakening line 124 and progressive delamination of peripheral welding 22. This delamination causes exposure of an indicated area 130 of the Edge initially covered by the lid. This area recently exposed allows the user to place the lips on a surface own to drink the liquid contained in the glass.

In this embodiment, the lid is formed advantageously by a complex film comprising three layers formed for example of polyester (PET) / film aluminum / polyethylene (PE) or oriented polypropylene (OPP) / film Aluminum / polyethylene (PE). Alternatively, the lid is constituted by a complex film comprising the two layers, for example polyester (PET) / polyethylene (PE), polypropylene oriented (OPP) / polyethylene (PE) or paper / polyethylene (PE).

The materials described for the packaging of Figures 1 to 5 can also be used advantageously.

In this embodiment, the line of weakening 124 is performed according to one of the embodiments which were planned for the previous embodiment.

Figure 8 shows another Alternative embodiment of a package according to the invention. In this embodiment, the weakening line 124 extends only in the area of the cover that covers the access opening. Thus, the line of weakening does not extend over the peripheral welding 22. Here, the weakening line delimits An outline not closed. In particular, a tongue 126 is formed which extends laterally on each side by two sections curves

The weakening line allows opening partial cover to introduce an object or substance into the container. Thus, the opening provided in the lid allows, by example, introduce a straw. It also allows to add in the container Some substances, such as sugar or salt. It also allows the introduction of a mixing element, such as a spoon or a rigid stirrer

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References cited in the description

This list of references cited by the applicant is intended solely to help the reader and not It is part of the European patent document. Although it has been put maximum care in its realization, errors cannot be excluded or omissions and the EPO declines any responsibility in this respect.

Patent documents cited in the description

US 3550835 A [0005]

GB 2156660 A [0006]

FR 2717449 [0029]

Claims (17)

1. Container (10) comprising a bucket-shaped container (12) that delimits an access opening (16) bordered by a peripheral welding zone (20) of a lid (14) and a flexible lid (14) of Initial sealing of the access opening (16) maintained over the area (20) according to a continuous peripheral weld (22), the cover (14), outside the peripheral weld (20), in a region covering the opening of access (16), a line (24; 124) of weakening of the cover that does not cross the cover, characterized in that said cover (14) is devoid of a fastening strip that extends the line of weakening towards the outside beyond the peripheral weld (22), and the weakening line (24; 124) and the weld (22) of the lid on the container (12) are such that the breaking strength of the lid (14) according to the weakening line (24; 124), especially the thickness of the lid is less than the resistance to rupture weld ra (22), after applying a pressure on the lid, and by the fact that the resistance to rupture of the lid is such that the sinking of the lid into the container when supporting a finger It causes the beginning of its rupture according to the weakening line (24), especially the thickness of the lid. 2. Container according to claim 1, characterized in that the weakening line (24) extends along a path completely included in the coverage region of the access opening (16). 3. Container according to claim 2, characterized in that the weakening line (24) delimits a closed contour completely included in the coverage region of the access opening (16). A package according to claim 1, characterized in that the weakening line (124) forms a line that extends at least in the coverage region of the access opening (16), between two different points of the peripheral welding (22). 5. Packaging according to any one of the preceding claims, characterized in that the tensile strength of the lid according to the line of weakness (24; 124) is included between 1 N / 15 mm and
70 N / 15 mm. A package according to any one of the preceding claims, characterized in that the weakening line (24; 124) delimits a tongue (26) where the dimensions correspond substantially to the dimensions of a human finger. 7. Container according to claim 6, characterized in that the weakening line (24; 124) forms at least one angular tip (128) on the contour of said tongue (26). 8. Container according to any of the preceding claims, characterized in that the lid (14) has a visible mark defining the position of the weakening line (24; 124). 9. Container according to any one of the preceding claims, characterized in that the lid (14) comprises at least one mechanical weakening treatment on at least one film of the lid on the weakening line (24; 124) . 10. Container according to claim 9, characterized in that said mechanical weakening treatment comprises a microporous weakening. 11. Container according to claim 9 or 10, characterized in that said mechanical weakening treatment comprises a partial trimming of at least one film of the lid (14) with the aid of a knife die according to the layout of the weakening line (24). 12. Container according to any one of the preceding claims, characterized in that the lid (14) comprises, according to the weakening line (24; 124), a weakening treatment by a high energy radiation according to at least one film of the lid 13. Packaging according to claim 12 and any one of claims 9 to 11, characterized in that the lid comprises at least two complex films, the first film undergoing a mechanical weakening treatment according to the line of the weakening line (24), the second film undergoing a weakening treatment by means of high energy radiation according to the line of the weakening line (24). 14. Package according to any one of the preceding claims, characterized in that the lid (14) is a complex in which the association of the films is chosen from the group consisting of polyester (PET) / polyamide (OPA) / polypropylene (PP), polyester (PET) / polyamide (OPA) / polyethylene (PE), polyester (PET) / polypropylene (PP), aluminum / polyester (PET), aluminum / oriented polypropylene (OPP), paper layer / polypropylene (PP), polyester (PET) / aluminum
minio / cast polypropylene (PPC), polyester (PET) / alumunium / polyethylene (PE), oriented polyamide (OPA) / aluminum /
cast polypropylene (PPC), oriented polyamide (OPA) / aluminum / cast polyethylene (PEC), polyester (PET) / polypropylene
leno (PP) / polyester (PET), polyester (PET) / aluminum / polyethylene (PE), oriented polypropylene (OPP) / aluminum / polyethylene
leno (PE), polyester (PET) / polyethylene (PE), oriented polypropylene (OPP) / polyethylene (PE), and paper / polyethylene (PE). 15. Container according to any one of the preceding claims, characterized in that the weakening line (24; 124) is shaped so that a sound is emitted at its initial rupture under the action of a gas circulating through the cover (14) broken. 16. Packaging according to any one of the preceding claims, characterized in that it comprises a product contained in the container (12) and that rests on one side of the container opposite to the lid (14), and by the fact that a free space (23) filled with a gas is defined between the lid (14) and the product, whose free space (23) is sufficient to allow deformation of the lid into the container (12) until the rupture of the lid (14), without the lid coming into contact with the product. 17. Packaging according to any one of the preceding claims, characterized in that the weakening line (24) has a breaking resistance by applying a pressure on the lid (14) which varies according to the length of the line of weakening (24).