WO2006016038A1

WO2006016038A1 - Package comprising a plastic container closed with a peelable inner seal heat-sealed to said container

Info

Publication number: WO2006016038A1
Application number: PCT/FR2005/001717
Authority: WO
Inventors: Jean-Luc Rick; Isabelle Jenny; Guy Boiron; Alain Grayer
Original assignee: Societe Alsacienne D'aluminium
Priority date: 2004-07-09
Filing date: 2005-07-05
Publication date: 2006-02-16
Also published as: EP1773683A1; ATE461131T1; DK1773683T3; FR2872788B1; PT1773683E; EP1773683B1; PL1773683T3; SI1773683T1; DE602005020016D1; FR2872788A1; ES2342949T3

Abstract

The invention concerns a package (1) comprising a container (10) provided with a surface (12) delimiting an opening (14), and an inner seal (16) sealed on the surface (129 and removable by peeling. The invention is characterized in that: a) the inner seal (16) comprises a support sheet (20) and an extruded (22') or co-extruded (22) plastic layer, forming or comprising a sealing layer (38', 38); b) said extruded (22') or co-extruded (22) layer is made of a material selected to adhere, through its outer surface, to said support sheet (20), and through its inner surface, to said surface (12) when sealed; c) said support sheet (20) is coated on its outer surface with a metal-plated film 21); d) and in that said extruded (22') or co-extruded (22) layer has a thickness Ec selected such that said peeling of the inner seal (16) brings about a coherent rupture of the extruded (22') or co-extruded (22) layer. The invention provides the advantage that said seals enable a broader selection of sealing techniques.

Description

PACKAGING COMPRISING A PLASTIC CONTAINER OBTAINED BY A THERMOSCELLET PELABLE OPERATOR RECIPIENT AUDIT

FIELD OF THE INVENTION

The invention relates to the field of packaging comprising pots or plastic containers generally containing fresh dairy products, typically yoghurt, sealed with lids.

STATE OF THE ART

These covers are formed of a flexible multilayer material comprising a sealing layer and capable of being sealed, typically by heat sealing, over a sealing range of a pot or plastic container, in order to seal it. This sealing range defines a filling and sampling aperture, and the lids, once heat-sealed on the range of the pot, can be separated from the pot by peeling. These lids may either form pre-cut lids or form a lidding leaf.

Generally, for a known type of packaging containing foodstuffs such as yogurt and other foods with limited shelf life, they are poured into pots or plastic containers which are then sealed with a foil seal of aluminum or a laminated paper / PET composite sheet from the container's range. The covers consist of a layer of lacquer which produces, during heat sealing of the covers, the adhesion of the cap on the container necessary for a closure free of germs. When peeling the seal from the container's range, separation occurs at the interface between the sealant and the sealant. substrate of the container in the form of an adhesive peel between the lacquered operculum and the range of the container.

PROBLEMS POSED

A disadvantage of the usual lids today is that they often tear during peeling when opening packages and they are detached as part of the beach. In addition, there is a risk, if the sealing conditions are not optimal, especially in the industrial sealing conditions, that the adhesion to the boundary surface between the seal layer of the seal and the substrate of the sealing range. sealing is so weak that it can occur, already during transport, a local separation of the lid and the range of the pot in the sealing region and thus an unplanned opening and in some cases even undetectable of the package, so that the shelf life of the content is no longer guaranteed.

The object of the invention is to provide lids, in the form of lidding sheets in a reel or in the form of pre-cut lidded stacks, which do not have the abovementioned disadvantages of lids made of aluminum foil or of paper composite multilayer material. / PET currently used and comprising a layer of sealing lacquer.

In addition, the invention relates to economical seals to manufacture and comply with current environmental guidelines for packaging materials.

DESCRIPTION OF THE INVENTION

According to the invention, the package comprises a plastic container having a range defining a filling and sampling aperture, said container containing a product, typically a food product, and a lid of a flexible sealing foil sealed by heat-sealing on the container surface by means of a sealing layer and peeled off thereof, said lid being secured to said range of said container by a sealing bead, and is characterized in that: a) the lidding sheet comprises a support sheet and an extruded layer or coextruded plastic layer, said extruded layer forming said sealing layer, said coextruded layer comprising a layer forming said sealing layer, b) said extruded layer or coextraded is formed of a material chosen to adhere, by its outer face, to said support sheet, and by its inner face, to said range during said heat-sealing, c) and in that said extruded or coextruded layer presents a thickness Ec chosen so that said peeling of the lid causes a cohesive rupture of the extruded or coextruded layer.

The covers according to the invention which comprise the combination of means a) to c) above solve the problems posed. Indeed, on the one hand, the applicant was surprised to find that it was possible to have an extruded layer providing the sealing layer function, and contributing significantly to the thickness of the lid, and that to his holding or his "hand", that is to say the impression felt by the consumer during the manual gripping of the edge of the lid for the opening of the sealed package. On the other hand, she was able to observe both the ease of peel opening of the lid and the stability of the peel force, probably due to the cohesive rupture of the extruded or coextruded layer, as well as the relative wide latitude or tolerance of sealing conditions, which is very important in practice. Indeed, she was able to observe that the lids according to the invention, probably due to a relatively large extruded layer thickness, ensured both a high stability of the peel force and especially a low sensitivity of the final seal. containers to the heat sealing conditions. Indeed, especially in the case where the covers form a sheet of operculum of large width, typically greater than 300 mm, there may be local differences in pressure of the heat sealing jaws, in the direction of the width of the foil. lidding. Thus, it appeared that the sealing quality of the extruded or coextruded layer was independent of the depth of the annular groove formed by the pressure exerted by a sealing tool during heat sealing. Moreover, these covers are of economical manufacture taking into account that a large part of the lid is constituted by an extruded or coextruded layer, so that at least the major part of the lid is an extruded or coextruded layer formed from a thermoplastic material in the least elaborate form that is, namely in the form of granules.

By "cohesive rupture of the extruded or coextruded layer", it is meant that, during the peel removal of a lid made with the operculum sheet according to the invention and sealed against the range of the opening of a plastic container or container, material separation occurs within the extruded or coextruded layer, with a portion of the extruded layer remaining on the sealing range of the container and another portion on the carrier sheet of the container operculum.

The structure of the extruded or coextruded layer is selected depending on the plastic material used for the carrier sheet and the container material. Indeed, the adhesion between the support sheet and the extruded or coextraded layer on the one hand, and between the extruded or coextraded layer and the container on the other hand; ^* after sealing the lid on the beach of the container, must be larger at least in the parts of the sealing region critical for sealing the sealing the cohesive bond within the extruded layer or coextradée , so as to have a cohesive rupture of the extruded layer. In addition, the layered structure of the extruded or coextruded layer is chosen according to the properties desired for the lid.

DESCRIPTION OF THE FIGURES

Figure 1 is a perspective view of a plurality of packages (1) comprising four containers or containers (10) of plastic material closed by lids (16) sealed and formed into a lidding sheet (17). On one of the containers (10), in the lower left, the peeling of a lid (16) was initiated by manually pulling on a corner of the cover or tear-off tab (19). On another of the containers (10), bottom right, the seal (16) has been partially removed on a portion of the container (10) where the sealing trace (183) of the sealing bead (18) has been shown , the seal (16) being present on the other part where the sealing bead (18) has been shown.

FIG. 2 shows, in enlarged view and in a vertical plane perpendicular to the plane of the lid, a section of the sealing bead (18) of a package (1) of FIG. 1, comprising a cover (16) consisting of a support sheet (20) and an extruded layer (22 ') forming said sealing layer (38') or a coextruded layer (22)

1 comprising said sealing layer (38), the different layers of said coextruded layer (22) not being shown distinct from each other.

Fig. 3 shows a cross section of a modality of a coextruded layer (22) comprising three layers (34), (36) and (38), while FIG. 4 represents a cross section of another coextruded layer modality comprising two layers (34) and (38). In order not to overload the figure, the layer (36) has not been hatched.

FIG. 5 schematically illustrates in cross-section similar to that of FIG. 3, the production of a lidding sheet (17) by supplying a support sheet (20) and co-extruding a layer (22). .

In this figure, the layers (21) and (40) have not been hatched.

FIG. 6, similar to the right-hand part of FIG. 5, shows a sealing foil mode (17) in which the coextruded layer (22) is assembled to a support sheet (20) comprising externally successively: primer layer (39), an imprint (41) and an overprint varnish layer (42). In this figure, the layers (39), (40) and (42) have not been hatched.

Fig. 7 is a perspective view of a sealing sheet reel (17). FIG. 8 represents, at its upper part, a cross-sectional view of a stack (17 ') of pre-cut lids (16'), and at its lower part, a top view of a pre-cut lid (16 '). ) printed.

DETAILED DESCRIPTION OF THE INVENTION

According to the invention, the support sheet (20) can be a plastic sheet. By "backsheet" is meant here the sheet which is coated on one side with the extruded layer (22 ') coextruded (22). However, the carrier sheet, although preferably made of plastic material, may also comprise a sheet of paper and / or aluminum. Thus, other layers of plastic, aluminum or paper, possibly printed and provided with a protective lacquer, may be disposed on the other side of said support sheet (20).

Said plastic sheet may be a plastic chosen from: a polyester, in particular polyethylene terephthalate (PET), a polyolefin, especially a polypropylene ^* (PP), polyamide (PA) or a copolymer cyclo- olefinic (COC). Said support sheet (20) may be covered on one of its inner or outer faces by a metallization layer (21) or a layer of a barrier material, in particular with water vapor, with oxygen or with UV radiation. Typically, said metallization layer (21) can cover said outer face of said support sheet (20), as shown in FIG. 5. Said support sheet (20) can be obtained either from a film of said material plastic supplied in coil, or possibly by a second extrusion or coextrusion from said plastic material supplied in the form of granules. Whatever the method of obtaining said support sheet, said support sheet and / or said metallization layer may comprise, on at least one of its faces, a layer of a primer (39, 40). . The thickness of the carrier sheet (20) is generally between about 7 and 200 μm and depends on the size and weight of the contents of the container to be closed.

According to the invention, said extruded layer (22 ') or coextruded layer (22) may have a thickness Ec ranging from 5 μm to 80 μm, and typically from 15 μm to 60 μm.

Depending on the type of cap, said extruded layer (22 ') or coextraded layer (22) may have a thickness Ec ranging from 25 μm to 40 μm, and typically a thickness ranging from 30 μm to 35 μm.

₍ As shown in FIG. 3, the coextruded layer (22) may comprise three layers and have an adhesive layer (34) joined to the backing sheet (20), an intermediate layer (36) and a sealing layer ( 38) assembled at the beach (12) of the container

(10).

However, as illustrated in FIG. 2, the coextruded layer (22) may comprise two layers and have an adhesive layer (34) joined to the backing sheet (20) and a sealing layer (38) assembled at the beach (12) of the container (10).

^{"* ',} The adhesive layer (34)" may contain "at least one ^{^*'} ^* following components: copolymers and / or graft copolymers and / or terpolymers including acid groups or ionomers, metallocene PE, linear PE, copolymers EVA copolymers, EMA copolymers, EEA copolymers, EBA copolymers, mixtures of these components or a polyolefin with a tackifying resin.

Said adhesive layer (34) can have a thickness ranging from 2 microns to 10 microns.

Said sealing layer (38) can contain at least one of the following components: copolymer of ethylene and vinyl acetate (EVA), copolymer of ethylene and methyl acrylate (EMA), copolymer of ethylene and butyl acrylate (EBA), copolymer of ethylene and ethyl acrylate (EEA), terpolymers with α-olefin monomers comprising esters.

Said sealing layer may comprise at least one of said components and at least one tackifying resin. δ

Said sealing layer may have a thickness ranging from 5 μm to 70 μm, and typically from 10 μm to 30 μm.

Said intermediate layer (36) may contain at least one of the following components: polyamide (PA) polymer and cycloolefin copolymer (COC) ₅ homo- and copolymers of polyolefins with or without inorganic or organic fillers. The intermediate layer (36) may comprise a mineral filler such as, for example, talc, at a weight content typically ranging from 5% to 30%, so as to promote the cohesive failure of said intermediate layer during the opening of said packaging.

Similarly, said sealing layer (38, 38 ') may comprise a mineral or organic filler, for example talc, at a weight content typically ranging from 5% to 30% by weight.

%, so as to promote cohesive rupture of said sealing layer upon opening of said package.

Said intermediate layer (36) may have a thickness ranging from 2 microns to 40 microns.

According to the invention, the container (10) can be made of a material chosen from: a polystyrene (PS), a polyester (PET), a polyolefin, in particular polyethylene (PE) or polypropylene (PP), the polymer of vinyl chlorine (PVC).

Said cover (16) is typically a printed cover, a printed pattern (41) that can be formed on an outer face of said support sheet (20) or said metallization layer (21) or said primary attachment layer (39). ). In this case, an overprint varnish (42) may cover said printed pattern (41).

Said operculum sheet (17) of said seal (16) may have a thickness ranging from 10 μm to 90 μm, said support sheet (20) having a thickness Es and said coextruded layer (22) having a thickness Ec such that the Ec / Es ratio is at least 1, and is typically between 2 and 4.

As illustrated in FIG. 2, said sealing bead (18), formed during said heat-sealing by a sealing tool (24), may comprise a collapsed annular central portion (180) bordered by two peripheral beads (181, 182), a inner bead (181) and an outer bead (182), said peripheral bead (181, 182) comprising an over-thickness t ¹ of said coextruded layer (22), said over¬ thickness being at least 1.5. .

Another object of the invention is constituted by a lid (16) intended to obtain, by heat-sealing on said container (10), said package (1) according to the invention, said lid (16) being a part of said foil lidding (17) or a pre-cut lid (16 ') of a stack (17') of pre-cut lids in said lidding foil (17).

EXAMPLES OF REALIZATION

Figures 1 to 8 illustrate embodiments of the invention.

Packaging (1) according to FIG. 1 has been manufactured.

Fig. 1 shows an arrangement with four pots or plastic containers (10) for packaging fresh products, for example yoghurt. In the illustrated example, four pots (10) are assembled to each other. Each pot (10) has a sealing pad (12) surrounding an opening (14) covered by a lid (16) of a lidding foil (17). The operculum sheet 17 is sealed on the sealing pad (12) in a sealing cord (18), cord (18) which has been shown in the bottom right of FIG. the cover (16), as illustrated at the bottom left of Figure 1 by an arrow (44) symbolizing a manual effort of peeling, provides access to the opening (14) of the pot and allows to take all or part of the pot content.

The individual pots (10) are assembled by the sealing pad (12) forming a plurality of closed pots, after filling, by a sealing sheet (17) forming a plurality of lids (16). To separate the pots (10), common edge edges are provided, which can be easily separated by hand along marked or cut lines of weakness in the sealing range (12). In recovery of these weakening lines, the lidding foil (17) is also cut into individual lids (16), so that each lid (16) can be removed individually. Each cap (16) is thus freely applied to the sealing surface (12) of the pot (10) and sealed along the sealing bead (18), so that outside this sealing bead (18), the package (1) comprises a tear tab 19 at each of the four corners of the sealing range (12) of each pot (10).

Fig. 2 shows the displacements or creep of material which occur during the sealing of the lidding foil (17) or the lid (16) on the sealing range (12) of the pot (10) of FIG. this same figure has also been shown the plot of the tear - noted from Sl to S5 - through the sealing bead (18) during the peeling of the cover (16) when exerted a manual effort of peeling (44) on a corner of the lid to separate it from the sealing range (12). Given the high temperature of the sealing tool (24) applied to the sealing foil (17) and the sealing range (12) of the underlying pot (10), typically comprising a sealing jaw as shown in broken lines in

^" Figuring out the ^" softened materials ^" in this ^" seal area ^"and the pressure exerted ^" by the sealing tool (24) on the seal (16) leads to the formation of a sealing bead (18) having , in the case of the pots of Figure 1 and in the plane of the lid (16), the shape of a square with rounded corners.

In cross-section, the sealing bead (18) comprises a collapsed annular central portion (180) bordered by two peripheral beads (181, 182), an inner bead (181) and an outer bead (182), said peripheral bead (181). , 182) comprising an over-thickness t 'of said coextruded layer (22), said over¬ thickness being at least equal to 1.5.Ec.

As regards the sealing range (12) of the pot (10), it comprises an annular groove (26), of depth t, corresponding to the annular central annular portion (180), and two sealing rings (28) and (29) corresponding to peripheral beads (181) and (182) of the sealing bead (18). Indeed, the material discharged by the formation of the groove (26) thus leads to the formation of sealing rings (28) and (29) on either side of the groove (26). By varying the sealing conditions, it is possible to vary the depth t of the sealing rings 28 and 29, which can typically range from 0.1 mm to 1 mm, while maintaining the tightness of the seal. With regard to the sealing foil (17) or the seal (16), under the pressure of the sealing tool (24), the coextruded layer (22) is discharged largely out of the groove (26). ) in the sealing range (12) of the pot (10), so that a thin annular central portion (32) substantially corresponding to said collapsed annular central portion (180) of the sealing bead (18) is formed, and that concentric annular beads (30) and (31) are formed with a thickness t 'greater than the thickness Ec of the coextruded layer (22), above the sealing rings (28) and (29).

The sealing bead (18) thus has, in particular thanks to these movements of material, a strong adhesion at the same time between the support sheet (20) and the coextruded layer (22), and between the coextruded layer (22) and the range (12) of the pot or container (10), which leads to a high sealing tightness of the sealing bead (18), in particular in the sealing regions corresponding to the marks S 1 to S 5 of FIG.

During the peeling of the sealing foil (17) or the lid (16) by a manual effort (44) ^" tending to ^' separate the operculum from the sealing range (12) of the pot (10) of the 1, it ^"appears a tear (33) first in the Sl region in the coextruded layer (22), typically in the sealing layer (38), which tear then propagates to the Sl region to region S5 , until complete separation of the seal (16), in the form of a cohesive rupture.

Indeed, the mechanical characteristics of the support sheet (20), in particular the hardness of the materials, are greater than those of the coextruded layer (22), so that the tear (33) propagates in the thickness of the layer coextruded (22).

In the example shown, the lidding foil (17) for example has a support layer (20) of 12 μm polyethylene terephthalate (PET) with a coextruded layer (22) with a basis weight of 30 g / m ² and the pot or container (10) is made of polystyrene (PS). The support sheet (20) can for example still be printed and be provided with a protective lacquer with a basis weight of 1 g / m ² . To form the package (1), a lidding sheet (17) comprising the extruded layer (22 ') forming said sealing layer (38') according to Fig. 2 is formed. To form the package (1) a lidding sheet (17) comprising the coextruded layer (22) according to FIG. 3 has also been manufactured. This coextruded layer (22) comprises three layers: an adhesive layer (34), an intermediate layer (36) and a sealing layer (38).

A lidding sheet (17) comprising the coextruded layer (22) according to FIG. 4 has also been manufactured. This coextruded layer (22) comprises three layers: an adhesive layer 34 and a sealing layer 38.

A lidding sheet (17) has also been manufactured as schematically illustrated in FIG. 5: a support sheet (20) having an outer metallization layer (21) and an inner layer of a primer (40) and a layer (22) comprising an adhesive layer (34) for adhering to the primer layer (40), an intermediate layer (20), and a coextruded layer (22) on said carrier sheet (20) ( 36) and a sealing layer (38). Thus, said lidding sheet (17) represented on the right part of FIG. 5 has been obtained.

Similarly, the lidding foil (17) of FIG. 6 is manufactured. In this sheet mode (17), the coextruded layer (22) - or the extruded layer (22 ') - has been assembled to a support sheet (20) comprising externally successively

a primer layer (39), an imprint (41) and an overprint varnish layer (42).

Regardless of the type of lidding foil (17), a lidding foil (17) has been obtained in the form of a coil, as illustrated in FIG. 7.

A stack (17 ') of pre-cut lids (16') was also formed from the lidding foil (17) as a coil of FIG. 7.

ADVANTAGES OF THE INVENTION The invention has great advantages.

Indeed, on the one hand, the lids (16, 16 ') according to the invention can be sealed on pots with sealing beads (18) of variable depth, without affecting the sealing of the packaging (1) and the adhesion of the seal on the pot, which is very advantageous in practice because it increases the adjustment tolerances of sealing tools on industrial line, and thus greatly reduces the scrap rate and health risks related to leaks in packaging (1). On the other hand, the invention makes it possible to obtain operculas (16, 16 ') or sealing foils (17) that are economical to manufacture insofar as one can have lids with a fraction of at least 50% of the thickness or at least 50% of the mass corresponds to an extruded layer (22 ') or coextruded layer (22) formed from plastic material in granules. This fraction can be much higher and reach 60, 70 or even 80%. Finally, the invention makes it possible to obtain, from one and the same support sheet (20), a whole family of lids (16, 16 ') or lidding foil (17) by varying the composition of the extruded layer (22 ') or coextruded layer (22), so that it is easy to have a large variety of covers, with various properties, as regards their weight, their "hand", their barrier properties , their adhesion and peel force or opening force, etc ....

LIST OF REFERENCES

Packaging 1 Container or Container 10

Heat sealing range of 10 12

Filling aperture of 10 14

Opercule 16

Cut-out lid 16 'Lidding foil 17

Stack of pre-cut operculas 17 ' Sealing cord 18

Sagged central part 180

Inner bead 181

Exterior bead 182 Trace of 18 of 12 183

Breakout tab 19

Support sheet 20

Metallization layer 21

Coextruded layer 22 Extruded layer 22 '

Sealing tool 24

Annular groove of 12 26

Annular bulges of 12 28, 29

Ring thicknesses of 22 30, 31 Thin ring center portion of 22 32

Tear of 18 33

22. Adhesive layer of 34

Intermediate layer of 22. ^" ...... ^" .1 ......... ^" ~ ^*" 36 ^"

Sealing layer of 22 38, 38 'Clinging primer of 20 or 21 (outer) ... 39

Primary fastening of 20 or 21 (internal) .. 40

Printing 41

Overprint varnish 42

Manual effort of peeling 44

Claims

A package (1) comprising a plastic container (10) having a pad (12) defining a filling and sampling aperture (14), said container containing a product, typically a food product, and a lid ( 16) of a flexible lidding sheet (17) sealed by heat-sealing on the beach (12) of the container (10) with the aid of a sealing layer and peeled off thereof, said lid being secured to said range of said container by a sealing bead (18), characterized in that: a) the lidding sheet (17) comprises a carrier sheet (20) and an extruded layer (22 ') or a coextruded layer ( 22) of plastic material, said extruded layer (22 ') forming said sealing layer (38'), said coextruded layer (22) comprising a layer forming said sealing layer (38), b) said extruded layer (22 ') or coextruded (22) is formed of a material chosen to adhere, by its face ex said backing sheet (20), and at its inner face, at said range during said heat-sealing, c) said backing sheet (20) is covered on its outer surface by a metallization layer (21), and in that said extruded (22 ') or coextruded layer (22) has a thickness Ec chosen so that said peel of the seal (16) causes a cohesive rupture of the extruded layer (22') or coextraded (22).

The package of claim 1 wherein the carrier sheet (20) is a plastic sheet.

3. Package according to claim 2 wherein the plastic sheet is made of a plastic material chosen from: a polyester, in particular polyethylene terephthalate (PET), a polyolefin, in particular a polypropylene (PP), a polyamide (PA) or a cycloolefinic copolymer (COC).

4. Packaging according to any one of claims 1 to 3 wherein said support sheet (20) and / or said metallization layer (21) comprises, on at least one of its faces, a layer of a primer ( 39, 40).

5. Package according to any one of claims 1 to 5 wherein said extruded layer (22 ') or coextruded (22) has a thickness EC ranging from 5 microns to 80 microns, and typically from 15 microns to 60 microns.

6. Packaging according to claim 5 wherein said extruded layer (22 ') or coextruded (22) has a thickness Ec ranging from 25μm to 40 microns, and typically a thickness ranging from 30 microns to 35 microns.

A package according to any one of claims 1 to 6 wherein the coextruded layer (22) comprises three layers and has an adhesive layer (34) joined to the carrier sheet (20), an intermediate layer (36) and a sealing layer (38) joined to the beach (12) of the container (10).

A package according to any one of claims 1 to 7, wherein the coextruded layer (22) comprises two layers and has an adhesive layer (34) joined to the carrier sheet (20) and a sealing layer (38) assembled at the beach (12) of the container (10).

9. Package according to any one of claims 7 to 8 wherein the adhesive layer (34) contains at least one of the following components: graft copolymers and / or copolymers and / or terpolymers comprising acid groups or ionomers, metallocene PE, Linear PE, EVA copolymers, EMA copolymers, EEA copolymers, EBA copolymers, mixtures of these components or a polyolefin with a tackifying resin.

10. Package according to any one of claims 7 to 9 wherein said adhesive layer (34) has a thickness ranging from 2 microns to 10 microns.

The package according to any one of claims 1 to 10 wherein the sealing layer (38, 38 ') contains at least one of the following components: ethylene-vinyl acetate copolymer (EVA), ethylene copolymer and methyl acrylate (EMA) copolymer of ethylene and butyl acrylate (EBA), copolymer of ethylene and ethyl acrylate (EEA), terpolymers with α-olefin monomers comprising esters.

The package of claim 11 wherein said sealing layer (38, 38 ') comprises at least one of said components and at least tackifying resin.

13. Package according to any one of claims 1 to 12 wherein said sealing layer (38, 38 ') has a thickness ranging from 5 microns to 70 microns.

14. Packaging according to claim 7, characterized in that the intermediate layer (36) contains at least one of the following components: polyamide (PA), cyclo-olefin polymer (COC) or copolymer, homopolymer or copolymer of polyolefins, with or without mineral or organic fillers.

The package of any one of claims 1 to 14 wherein said sealing layer (38, 38 ') comprises a mineral or organic filler.

16. Package according to any one of claims 7 or 14 wherein said intermediate layer has a thickness ranging from 2 microns to 40 microns.

17. Package according to any one of claims 1 to 16 wherein the container (10) is made of a material selected from: polystyrene (PS), polyester (PET), polyolefin, in particular polyethylene (PE) or polypropylene (PP), the vinyl chlorine polymer (PVC).

A package according to any one of claims 1 to 17 wherein a printed pattern (41) is formed on an outer face of said carrier sheet (20) or said metallization layer (21) or said primary bonding layer ( 39).

The package of claim 18 wherein an overprint varnish (42) overlies said printed pattern (41).

20. Package according to any one of claims 1 to 19 wherein said sealing bead (18) formed during said heat sealing by a sealing tool (24) comprises a collapsed annular central portion (180) bordered by two peripheral beads (181). , 182), an inner bead (181) and an outer bead (182), said peripheral bead (181, 182) comprising an over-thickness f of said coextruded layer (22), said over-thickness being at least 1 , 5.Ec.

21. Package according to any one of claims 1 to 20 wherein said sealing bead, formed during said heat sealing by a sealing tool comprises a collapsed annular central portion bordered by two peripheral beads, an inner bead and an outer bead, said beads. peripherals comprising a sur¬ thickness of said coextruded layer, said over-thickness being at least equal to 1.5.Ec.

A seal (16) for sealing by heat sealing to the range (12) of the container (10) of said package (1) according to any one of claims 1 to 21, said seal (16) being a part of said foil lidding (17) or a pre-cut lid (16 ') of a stack (17') of pre-cut lids in said lidding foil (17).

A method of making a lidding foil (17) for forming said lids according to claim 22 or forming a portion of said package according to any one of claims 1 to 21, wherein: a) supplying said carrier foil (20), typically in coil form, said carrier sheet typically being covered with said metallization layer (21), and being a film typically chosen from the films of: PET, PA ₅ PP, COC, said film having a thickness ranging from 7 μm to 2 μm μm, b) coextrusion is applied to the inner face of said carrier sheet (20) a coextruded layer (22, 22 ') internally comprising said adhesive layer (34) for adhering to said carrier sheet (20), and externally said sealing layer (38), said coextruded layer (22, 22 ') having a thickness Ec ranging from 25 μm to 40 μm.

24 :! The method of claim 24 wherein said metallization layer (21) covers the outer surface of said carrier sheet (20).

The method of any of claims 23 to 24 wherein said coextruded layer (22, 22 ') comprises between said adhesive (34) and seal (38) layers, said intermediate layer (36) of thickness ranging from 2 μm to 40 μm.