EP2675730B1

EP2675730B1 - Container for the preparation of beverage comprising an improved perforable foil and method for preparing a beverage

Info

Publication number: EP2675730B1
Application number: EP12702514.6A
Authority: EP
Inventors: Arnaud Gerbaulet; Daniel Abegglen; Sébastien Pelletier; Alexandre Perentes; Patrick Benz
Original assignee: Nestec SA
Current assignee: Nestec SA
Priority date: 2011-02-16
Filing date: 2012-02-02
Publication date: 2015-03-25
Anticipated expiration: 2032-02-02
Also published as: MX2013009416A; WO2012110323A1; US20130323370A1; CN103380066A; AU2012217357A1; IL227335A0; KR20140010078A; SG192001A1; AR085270A1; ZA201306910B; BR112013020483A2; JP2014505564A; PT2675730E; EP2675730A1; CA2824195A1; MA34895B1; ES2535937T3

Description

Field of the invention:

The present invention relates to the field of the preparation of beverages by the use of a portioned beverage container in a beverage preparation device. The invention also relates to a method for preparing a beverage from such a container.

Background of the invention:

The preparation of a beverage such as coffee by means of a portioned beverage container, such as a capsule has become very popular. Many brands and food manufacturers now propose their own beverage capsule system. One principle consists in injecting liquid in a container such as by perforating an entry wall of the container. The liquid then interacts with the beverage ingredients contained in the container and the resulting beverage extract is drained through perforations created in or through the container. Usually, a pressure of liquid is created inside the container to promote the extraction of certain aromatic compounds in particular for coffee. A pressurized extraction of the beverage ingredients can be obtained by forcing liquid in the confined volume of the capsule using a pressure pump or centrifugation, such as by centrifuging the container in a centrifugal preparation device.
In EP1165398 , a sealed cartridge is designed to be extracted under pressure. The cartridge comprises a cup with a base containing roasted coffee and a frusto-conical wall, a circular lip and a cover welded to the periphery of the lip. The cartridge comprises in the cup near the base, where perforating means are introduced for creating openings for liquid to be fed in the cartridge, a layer such as a fabric or a valve for avoiding the solid substance to leave the capsule when the perforating means, e.g., blades, are retrieved from the cartridge.
Other systems, such as described in WO02080745 or EP1967099 , provide a container with a flexible membrane which is perforated by one or several intruding members. The flexible membrane, generally of lower thickness, is easier to perforate than the thicker/more rigid (plastic or aluminum) body of the container.
EP1247756 relates to a capsule with a plastic body and a lid. The plastic body includes an opening for introduction of an emptying device. The opening is closed and sealed by a flexible membrane which has a lower resistance to rupture, than the remainder of the body.
WO2006030461 relates to a capsule for the preparation of beverages within dispensing machines, has a sealing film which is perforated at the time of the use when the pressurized infusion water is supplied to the capsule and deforms the film, bringing it into contact with underlying perforation means fixed to the same capsule.
US2010288131 relates to a single-use mineral composite beverage brewing cup and cartridge. The cup is formed from polymeric materials with calcium carbonate and the lid is made of metal foil laminated to a heat sealable polymeric layer (e.g., metalized polypropylene).
US7552672 discloses a cartridge containing one serving of coffee powder for preparing a coffee beverage. The bottom of the cartridge is provided with a passage covered by a gas-tight foil. The foil is manually removed before the cartridge is inserted into the coffee machine or perforated by an outlet piercing sting. Between the passage and the coffee powder, a filter element is disposed, preventing coffee powder to escape from the cartridge. The passage prevents an hydraulic pressure build-up in the cartridge, which would lead to the formation of froth.
US6607762 relates to an outer container with an access opening. A filter element is received in and configured and arranged to subdivide the interior of the container into first and second chambers. A beverage medium is stored in the first chamber. A lid closes the access opening. The lid has a first section overlying the first chamber and a second section overlying the second chamber. The first section of the lid is yieldably piercable to accommodate an inflow of liquid into the first chamber for infusion with the beverage medium to produce a beverage. The filter element is permeable to accommodate a flow of the beverage from the first chamber into the second chamber, and the second section of the lid is yieldably piercable to accommodate an outflow of the beverage from the second chamber to the exterior of the cartridge.
A capsule for preparing a beverage or liquid food and a system using brewing centrifugal forces is described in WO2008/148604 . Typically, the capsule is formed of a body containing a beverage making substance such as coffee powder which is closed by a membrane. The membrane is perforated by a water injection needle of the device in the central part of the membrane for injecting liquid in the capsule and is simultaneously perforated in the peripheral part of the membrane by many smaller needles for extracting the beverage out of the capsule. The problem with such capsule is that the extraction perforators must be sharp enough to provide sufficiently large openings in the membrane. As a consequence, liquid and/or solids can easily flow back also along the surface of the water injection needle by the effect of the centrifugal momentum. As a result, such liquid and/or solid can contaminate the external surface of the container and dirty the extraction device. These residues may also be drained into the beverage. Of course, this is not desirable for the taste and the texture of the beverage.
WO2010/063644 relates to a capsule with a flexible membrane configured in the central inlet portion to provide liquid tightness between the liquid inlet and the surface of an injection needle of the beverage production device to prevent liquid from leaking from inside toward outside of the capsule. The capsule is also configured to allow centrifuged liquid to traverse the upper wall in the peripheral outlet portion. More particularly, the tightness-producing layer can be obtained by a resilient or soft material comparatively thicker than the same material in the peripheral outlet portion, or a more resilient or softer thickness of material than the material thickness in the peripheral outlet portion and/or a fibrous or foam material localized in the central inlet portion, to create in the central inlet portion, a liquid tightness by contact of such material with the outer surface of an injection needle of the device when said needle is introduced through the upper wall in the central inlet portion. The tightness-producing layer may be a layer of a laminate comprising other layers such as aluminium.

Summary of the invention:

The present invention aims at providing an improvement for a portioned beverage container to facilitate perforation by an intruding member of the beverage producing device, e.g., a liquid injector, while still reducing leakage and avoiding by-pass of liquid at the injection site of the container. The present invention further facilitates filtering of the beverage and reduces resurgence of solids without the requirement for an additional filter in the container. The present invention also reduces backflow of liquid and/or solids such as after withdrawal of the intruding member. The present invention also aims at providing a simpler, more industrial and more economical container than prior art solutions. In particular, the invention aims at reducing the number of parts constituting the container while maintaining the previous functions and advantages.
For this, the present invention is broadly defined by the main independent claim 1. The dependent claims further define the invention.
More particularly, the invention relates to a portioned container, for the preparation of a beverage in a beverage producing device, comprising a body having a main cavity and a foil connected to the body for closing said main cavity; said main cavity containing beverage ingredients,
wherein the foil is perforable in axial direction above the cavity by an elongated intruding member of the beverage preparation device,
wherein the foil comprises at least a base layer and at least a tightness-producing layer;
said tightness-producing layer constituting an inner layer underneath the base layer; wherein said tightness-producing layer and said base layer are adhesively bonded above the cavity at least in a first region of the foil and are free of adhesive bond in at least a second region of the foil; such second region being the region intended for being perforated by the elongated intruding member forming a tightness engagement with the surface of the elongated intruding member.
The term "container" refers to any single-use rigid or semi-rigid packaging container containing beverage ingredients such as a capsule. Other synonymous to a capsule are "cartridge" or "pod". The term "ingredients" means any suitable beverage substance such as ground coffee, soluble coffee, leaf tea, soluble tea, herbal tea, cocoa powder, dairy powder, culinary powder, baby food, other beverage nutritional ingredients and any combinations thereof. The term "tightness" is meant here to designate the tightness to a liquid medium (i.e., injected water, liquid coffee extract) and/or solids (i.e., non-fully soluble particles such as coffee grains). The term "layer" is meant here to designate a single layer or a combination of sub-layers assembled together. The term "foil" or "flexible membrane" are used for designating the same closing element for the container.
In the second region, in which the base layer and the tightness-producing layer are free of adhesive bond, the base layer and the tightness-producing layer preferably overlap.
In a preferable mode, the second region, in which the base layer and the tightness-producing layer are free of adhesive bond, represents less than a third of the total surface area of the foil above the cavity.
The second region, in which the base layer and the tightness-producing layer are free of adhesive bond, is a circular region in the central axis (I) of the capsule.
More particularly, the second region in which the base layer and tightness-producing layer are free of adhesive bond represents an axially centered region which is less than a third, preferably less than a 1/4 of the total surface area of the foil above the cavity. In particular, the second region has a surface area comprised between 0.5 and 1000 mm², preferably 3 and 350 mm² and the foil has a total surface area comprised between 500 and 150000 mm², preferably between 1000 and 5000 mm².
The term "free of adhesive bond" means that the base layer and the tightness-producing layer are not connected together at all or that the two layers are connected by a bond having a peeling resistance of less than 0.5 N/15mm according to the DIN53357 standard.
According to an aspect of the invention, the tightness-producing layer has a elongation at break of at least 200%, preferably at least 300%. The elongation at break is measured by ISO 527.3 standard (Tensile Properties of Films and Sheets).
In the foil of the container, the tightness producing layer is preferably made of a material chosen amongst: PP, PE, their copolymers or their terpolymers, PVC, elastomeric thermoplastic, a biodegradable material and combinations thereof.
The tightness-producing layer is preferably made of polypropylene, most preferably cPP (cast polypropylene). The tightness-producing layer is preferably formed of PP having a thickness of between 3 and 500 microns, more preferably between 10 and 100 microns. Most preferably, the tightness-producing layer is comprised between 10 and 50 microns, for example, 30 microns.
The tightness-producing layer can also be a biodegradable material such as natural fibers (e.g., cellulose), starch, PLA and combinations thereof. Preferably, the biodegradable material is a blend of cellulose, starch and PLA.
When the tightness-producing layer is perforated by the liquid injection member, the layer elongates and creates an elongated sealing portion of film such as sealing lips around the surface of the intruding member.
The base layer has preferably an elongation at break which is lower than the elongation at break of the tightness-producing layer to ensure that it breaks earlier during insertion of the intruding member in the region in which the base layer and the tightness-producing layer are free of adhesive bond. Preferably, the base layer has an elongation at break of less than 200%, most preferably less than 100% according to ISO 527.3 standard (Tensile Properties of Films and Sheets).
The base layer preferably comprises at least one sub-layer configured for forming a decorative or printable support. The support can be printed with ink or a metal deposit, embossing or combinations.
The base layer comprises aluminium, polyester such as PET, PLA, polyolefin(s), polyamide, starch, and combination thereof. The base layer can be formed of a laminate having two or more sub-layers of these materials.
The base layer preferably comprises an additional gas barrier layer (if absent from the preceding list). The gas barrier layer can be chosen amongst: aluminium, EVOH, PA6, Siox or Alox coating and combinations thereof.
More preferably, the foil comprises a base layer with two sub-layers, mainly, an external sub-layer made of PET and an internal sub-layer made of aluminium. The aluminium sub-layer serves the function of preventing undesirable transmission of light, moisture and oxygen. As a preferred example, the foil is made (from the outer to inner side of the foil): 8-20, preferably 12 microns of PET; 5-15, preferably, 8 microns of aluminum; 15-30, preferably 30 microns of cPP.
cPP is known as "cast polypropylene" and is a film of polypropylene made from copolymer and/or homo-polymer polypropylene. Other extrusion process can be used to produce PP layer such as co-extrusion cast, mono or co-extrusion blown film. In case of a coextruded structure, all layers can be made from the same PP grade or made from different grades. The preferred polypropylene has preferably a density between 0.860 and 0.92 and a melt index from 0.5 to 20g/min (ISO 1133, 230°C, 2.16kg).
The body of the capsule is preferably formed of rigid material such as aluminium and/or polymer such as polypropylene. A multi-layer of aluminium and polypropylene is preferred.
The container of the invention may comprise an internal filter which separates the main cavity into two internal chambers; a first chamber containing the beverage ingredients and a second chamber which is free of beverage ingredients. However, in a preferred mode, the capsule is free of any internal filter. In this mode, the filtering of the beverage is thereby obtained through the interstices or cracks which are provided by perforation with the beverage extracting members, such as for example those described in WO2010/066736 , the first region of the foil where the tightness-producing layers and said base layer are adhesively bonded.
The invention further relates to a method for preparing a beverage from a container as aforementioned in a beverage preparation device comprising:

providing the portioned beverage container in the beverage preparation device,
axially inserting through the foil of the container, at least one elongate intruding member comprising at least one liquid outlet opening; wherein during insertion, the tightness-producing layer stretches to form a stretched portion at least until it becomes perforated by the intruding member,
injecting liquid in the container through said intruding member.

Therefore, as a result, a liquid-tight arrangement can be obtained between the surface of the intruding member and the elongated portion of the tightness-producing layer.
The stretched portion of the tightness-producing layer thereby forms a tight sealing engagement on the surface of the elongated intruding member above the at least one outlet opening.
In particular, the elongated portion may form one or more free lips or a sheath which seals with the surface of the intruding member. More particularly, the at least one outlet opening communicates with the cavity below the elongated portion formed by the tightness-producing layer.
In the preferred method, the elongate intruding member is inserted along the central axis (I) of the container representing the axis of rotation during centrifugation of the container in the device. Furthermore, a plurality of liquid outlets are perforated in the first region of the foil and the capsule is centrifuged in the beverage preparation device around its central axis (I) to force liquid through the beverage ingredients in the main cavity and to force it to leave the container through the perforated liquid outlets. The beverage outlets are preferably perforated in the second region of the foil close to the periphery where the centrifugation forces are higher.
The container of the invention may also be used in a beverage preparation device wherein the extraction forces in the container are obtained by injecting a liquid under pressure in the capsule without requiring centrifugation of the capsule ("non-centrifugal beverage preparation device").

Brief description of the figure:

Figure 1 is a perspective view of a container according to the invention;
Figure 2 is a cross-sectional view of the container of figure 1;
Figure 3 is an enlargement view (E) of the cross-section view of figure 1;
Figures 4 to 6 show a schematic representation of the perforation of the container by a intruding member of the beverage producing device;
Figure 4 shows the foil of the container before perforation by the intruding member;
Figure 5 shows the foil when being perforated by the intruding member, in particular, when the base layer is broken and the tightness-producing layer is stretched by the intruding member;
Figure 6 shows the foil after insertion of the intruding member and injection of liquid inside the container;
Figure 7 is a top view of a variant of the container of the invention.

Detailed description of the preferred embodiments:

An example of portioned beverage container 1 is illustrated in Figures 1 to 3. The container may comprise a body 2 having the form of a cup forming a main cavity 3 extending along a central axis I. The body extends outwardly by a peripheral flange 4. The main cavity contains beverage ingredients such as a portion 5 of ground coffee powder in loose or pre-compacted form. The container further comprises a foil or flexible membrane 6 closing the body and sealed onto the flange 4. The body can be made of gastight material such as aluminium or a aluminium-PP. The foil is preferably gastight, in which case, protective gas contained inside the container may force the foil to bulge outwardly as represented in figure 1. Protective gas may be gas originated from the beverage ingredients during a degassing stage occurring after sealing the foil onto the body, such as CO₂ and/or may be gas added or flushed before or during sealing of the foil such as CO₂, nitrogen and combination thereof. Of course, it may be that the foil is not fully (or does not require to be) gastight and/or is not sealingly connected to the flange of the body. In which case, gas transfer between the external environment and the inside of the container is made possible.
As illustrated in figure 3, the closing foil 6 is formed by a multi-layer configuration. The foil is configured to provide at least a base layer 7 and at least a tightness-producing layer 8 placed underneath the base layer 7. The base layer is configured to have a lower elongation at break than the tightness-producing layer.
The base layer 7 and tightness-producing layer 8 are adhesively connected in a first region 9 above the cavity and overlap but are free of adhesive connection in a second region 10 or tightness-producing region above the cavity. For this, the base layer 7 is connected by an adhesive layer 11 which is interrupted in the second region 10, where the layers still overlap, while it is present in the first region 9 between the base layer 7 and the tightness-producing layer 8 (The outer limit of the region 10 is virtually defined in dotted line on figure 1). The first adhesively connected region 9 of the foil is preferably a peripheral region relative to the second non-adhesively connected region 10 which is more central. However, the opposite configuration could as well be envisaged for use of the container in a non-centrifugal beverage preparation device. Note that the adhesive layer 11 can also extend in the free-of-bond region 10 without creating an adhesive bond between the layers 7, 8.
In the preferred embodiment, the region 10 is formed as a circular region centered around the central axis I. More than one region 10 can be provided in the foil. The number and the location of regions 10 are function of the number and location of the liquid intruding members (e.g., liquid injector). For example, several circular regions may be distributed along an annular path of the foil for enabling insertion of an equal (or lower) number of intruding members.
In the first region 9, i.e., outside the tightness-producing region 10, where there would be no intention to provide a liquid-tight sealing engagement between the foil and a liquid intruding member, the base layer 7 and tightness-producing layer 8 are preferably connected with an adhesive 11 that provides a tear resistant bond under the force exerted by the intruding member before perforation of the tightness-producing layer 8. A suitable adhesive can be, for instance, aliphatic or aromatic adhesive used in a lamination coating process.
The base layer 7 of the foil may comprise several sub-layers 12, 13 connected by an adhesive film 14. For example, the sub-layer 12 connected to the tightness-producing layer 8 can be an aluminium layer. By "aluminium" it is meant a layer containing aluminium as its main constituent such that it can be an aluminium alloy. The sub-layer may also be another metal layer or a metalized polymer layer. The aluminium sub-layer may be embossed or engraved for decorative purpose. The outermost sub-layer may be a decorative or printable support layer such as PET (polyethylene terephtalate), PLA (polylactic acid) or polyolefin(s). The sub-layer 13 may serve as a support for ink, for an image, a structure in relief and/or recess such as decorative embossing. The decorative sub-layer may be transparent, translucent, colored or opaque.
The tightness-producing layer 8 can be formed of a single layer or more than one layer. In a preferred example, the tightness-producing layer 8 is polypropylene, more particularly cPP.
The adhesive connection of the base layer and tightness-producing layer in the region 9 has for effect that upon axial insertion of an intruding member through the foil, the tightness-producing layer is prevented from stretching freely and perforates together with the base layer. It will also result that in the region 9, the perforation obtained by an intruding member will provide no effective liquid sealing engagement at the surface of the intruding member since the tightness-producing layer will not stretch but will rather tear jointly with the base layer. Since the energy required for tearing the bonded layers is relatively high, larger cracks tend to propagate in the vicinity of the intruding member. The consequence will be so that in the region 9, outside the liquid tightness-producing region 10, it is possible to extract the beverage via one or more intruding members (e.g., such as beverage extractors) simply by effect of the beverage passing in the cracks formed in the perforated foil. As a benefit, the outlet intruding members do not require through-openings for extracting the beverage from the capsule which are known as becoming easily clogged such as by coffee particles or limestone scale. Also, the filtration can be obtained without using a dedicated filtering element in the capsule. Therefore, the extraction system becomes more simple and more reliable and the capsule's cost is also considerably reduced.
A thin adhesive layer may also be applied to the external surface of the tightness-producing layer 8 to provide adhesive properties of the foil onto the body of the capsule. Such additional layer can be a heat seal lacquer such as a PU lacquer (not shown in figure 3).
Figures 4 to 6 illustrate the method of perforating the container in a beverage production device while providing a tightness arrangement. More particularly, the perforation of the region 10 (i.e., the region of the foil without bond between layers 7 and 8) of the foil is obtained by an intruding member 15 such as a liquid injector of the beverage producing device. The container is typically received in a container holder and the intruding member which can be part of a liquid injection part of the device is engaged against the foil of the container such as by mechanical closure of the holder and liquid injection part around the container (not shown). The intruding member 15 has preferably a larger base and an opposite free end provided with outlet openings 17. The intruding member typically comprises an axial internal water conduit (not visible) which ends by several peripherally distributed openings 17 near the free end. The free end is preferably relatively rounded to avoid cutting the layer 8 before it sufficiently stretches. As shown in figure 5, the base layer 7, such as made of a multi-layer of PET and aluminium, breaks while the tightness-producing layer 8 stretches during the axial insertion of the intruding member. When the limit of elongation of the tightness-producing layer 8 is reached, it breaks but the broken lips 16 of the layer tends to retract slightly around the intruding member so to create a tight seal above the liquid outlets 17 of the intruding member 15. Therefore, a backflow of liquid and/or solids is prevented around the surface of the intruding member. Preferably, the distance "A", representing the axial dimension of the stretched portion of the tightness-producing layer, is lower than the total axial length "L" of the intruding member. Even preferably, the distance "A" is lower than the axial length "L1" representing the distance separating the outlet openings 17 from the base of the intruding member. Preferably, the larger diameter "D" of the intruding member is lower than d/n, where "d" is the diameter of the region 10 and "n" is comprised between 1.5 and 5. For example, A is comprised between 5 and 8 mm, "d" is comprised between 5 and 14 mm and the thickness "t" of the tightness-producing layer is comprised between 10 and 500 microns most preferably between 10 and 200 microns. Additional information regarding the beverage production device can be found in the following patent publications which are given as an illustrative nonlimiting purpose: WO2008/148601 , WO2008/148646 ; WO2010/026045 ;
According to the mode of figure 7, the container of the invention may comprise a foil with a tightness-producing region 10 which forms an annular region around and distant from the central axis I. The annular region has an inner edge distant of distance "k" from axis I and an outer edge distant of distance "k1" from axis I. The distances "k" and "k1" are determined in function of the location and the diameter "D" of the intruding member (represented by reference 15 in dotted lines) or members of the beverage producing device. For example, the distances k is about 1.9-2.1 cm and k1 is about 2.4-2.6 cm. The advantage of such configuration is that it provides the possibility to have an intruding member (e.g., water injecting needle) which is off-centered relative to axis I. When the intruding member is retrieved from the container, the foil closes off automatically (by the tightness-producing region shrinking) and the back-flow of liquid can be reduced or prevented. This container may be used in a non-centrifugal beverage producing device such as a Nescafé^® Dolce Gusto^® beverage machine in which the water injecting needle of the device is placed offset relative to the central axis I of the container such as it is described in the following patent applications: WO 2005/020769 , WO2006/082064 WO2008/107348 , WO2008/107281 and WO 2010/066736 .
The foil 6 of the container can be produced by lamination coating in which the adhesive layer is coated on selective parts of the base layer or tightness-producing layer. Then, the other layer (tightness-producing layer or base layer) is laminated onto the partially coated layer. Different lamination techniques can be employed such as cold seal lamination or triplex lamination including a partial lamination with the coating adhesive.

Claims

A portioned container (1), for the preparation of a beverage in a beverage producing device, comprising a body (2) having a main cavity (3) and a foil (6) connected to the body for closing said main cavity; said main cavity (3) containing beverage ingredients (5),
wherein the foil (6) is perforable in axial direction above the cavity by an elongated intruding member (15) of the beverage preparation device, wherein the foil (6) comprises at least a base layer (7) and at least a tightness-producing layer (8);
said tightness-producing layer (8) constituting an inner layer underneath the base layer (7);
characterized in that:
said tightness-producing layers (8) and said base layer (7) are adhesively bonded above the cavity (3) at least in a first region (9) of the foil and are free of adhesive bond in at least a second region (10) or tightness-producing region of the foil, such second region being the region intended for being perforated by the elongated intruding member (15) and forming a tightness engagement with the surface of the elongated intruding member (15).
Container according to claim 1, wherein the second region (10), in which the base layer (7) and the tightness-producing layer (8) are free of adhesive bond, represents less than a third of the total surface area of the foil (6) above the cavity.
Container according to claims 1 or 2, wherein the tightness-producing layer (8) has an elongation at break of at least 200%, preferably at least 300% (ISO527-3).
Container according to any one of claims 1 to 3, wherein the second region (10) in which the base layer and the tightness-producing layer are free of adhesive bond, is a circular region in the central axis (I) of the capsule.
Container according to any one of claims 1 to 4, wherein the tightness-producing layer (8) is made of PP, PE or their copolymers or their terpolymers, PVC, elastomeric thermoplastic, a biodegradable material and combinations thereof.
Container according to claim 5, wherein the tightness-producing layer (8) is formed of PP having a thickness of between 3 and 500 microns, preferably 10 and 200 microns.
Container according to any of the preceding claims, wherein the base layer (7) has an elongation at break which is lower than the elongation at break of the tightness-producing layer.
Container according to any one of claims 1 to 7, wherein the base layer (7) comprises at least one sub-layer (13) configured for forming a decorative or printable support.
Container according to any one of claims 1 to 8, wherein the base layer (7) comprises aluminium, polyester such as PET, PLA, polyolefin(s), polyamide, starch, and combination thereof.
Container according to claim 9, wherein the base layer further comprises an additional gas barrier sub-layer (14).
Container according to claim 10, wherein the gas barrier sub-layer (14) is chosen amongst: aluminium, EVOH, PA6, Siox or Alox coating and combinations thereof.
Container according to any one of claims 8 to 11, wherein the foil comprises a base layer (7) with two sub-layers (13, 14), mainly, an external sub-layer (13) made of PET and an inner sub-layer (14) of aluminium.
Container according to any one of claims 8 to 12, wherein the tightness-producing layer (8) is made of polypropylene.
Method for preparing a beverage from a container according to any of the preceding claims in a beverage preparation device comprising:
- providing the portioned beverage container (1) in the beverage preparation device ,

- axially inserting through the foil (6) of the container, at least one elongated intruding member (15) comprising at least one liquid outlet opening (17); wherein during insertion, the tightness-producing layer (8) stretches to form an stretched portion at least until it becomes perforated by the intruding member,

- injecting liquid in the container through said intruding member..
Method according to claim 14, wherein the stretched portion of the tightness-producing layer (8) forms a tight sealing engagement on the surface of the elongated intruding member (15) above the at least one outlet opening (17).