AU2011281237B2

AU2011281237B2 - Sealed capsule and system for a beverage extracted under pressure

Info

Publication number: AU2011281237B2
Application number: AU2011281237A
Authority: AU
Inventors: Jacques Pascot
Original assignee: MOCOFFEE AG
Current assignee: MOCOFFEE AG
Priority date: 2010-07-21
Filing date: 2011-07-19
Publication date: 2014-10-09
Anticipated expiration: 2031-07-19
Also published as: FR2962893A1; KR20130042573A; AU2011281237A1; EP2595516A1; EP2595516B2; EP2595516B1; WO2012011053A1

Abstract

The invention relates to a sealed capsule for preparing a beverage by injecting pressurised water, including a sidewall (2), a bottom wall (4), and a top wall (6) defining a hermetically sealed space containing a substance to be extracted, the bottom wall and the sidewall being made as an integral part forming a rigid or semi-rigid shell, a collar (10) extending from one end of the sidewall, the top wall being provided in the form of a flexible membrane attached to the collar, the bottom wall being configured so as to be perforated by perforation tips of a perforating plate when a certain water pressure is reached inside the capsule, characterised in that the bottom wall includes a main central portion (20) to be perforated and a folded portion (22) rigidly connecting the main central portion to the sidewall, the folding portion including one or more folds (18, 24, 28) enabling the central portion to move toward the inside and outside of the capsule at an amplitude corresponding to an amplitude required for perforating the bottom wall without applying sideways tension to the bottom wall.

Description

WO 2012/011053 PCT/IB2011/053215 Sealed capsule and system for a beverage extracted under pressure The present invention relates to a capsule or a system for preparing beverages extracted 5 under pressure, notably coffee, but also other beverages such as tea, hot chocolate, milk and broths. Hermetic capsules have several advantages: convenience of use, the possibility of having beverages of different aromas in small portions, the possibility of being able to produce 10 beverages with consistency and taste in a highly controlled and reproducible way, and the possibility of storing the product and preserving the taste for a long time. Some of the capsules on the market contain aluminum, which poses an environmental problem because of the significant energy required for producing aluminum and then 15 because of the problem of processing wastes. Other capsules are made in plastic material which is more easily recyclable or which may be burnt with the dregs of the coffee or other substances to be extracted after use, plastic materials having a more favorable ecological balance than aluminum. However, there is a benefit of reducing as much as possible the use of plastic and of other package materials in the capsule. This should however be done so as 20 not to be detrimental to the quality of extraction of the beverage. In the case of coffee of the espresso type, it is sought to obtain a creamy mousse, which requires high pressure extraction and good irrigation of the coffee inside the capsule. One of the aspects which is difficult to control in a system with capsules, is to ensure homogeneous 25 distribution of the pressurized water through the coffee grains and avoid the formation of preferential flow channels. A non-homogeneous water passage through coffee grains or other substances to be extracted reduces the extraction level and also reduces the pressure gradient so as not to have optimum extraction. By good control of these extraction parameters, it is possible to use a reduced amount of coffee (or of another substance to be 30 extracted) as compared with a conventional coffee machine (i.e. without any capsules). In existing systems, the capsules are often very small. This is sufficient for producing a small coffee of the espresso type, notably from the fact that it is easier to control the extraction with an extraction volume and surface which are smaller. The larger the capsule, the more it 35 is difficult to ensure proper and homogeneous passage of pressurized water through the coffee bed or of other substances to be extracted in the capsule.

2 Any discussion of documents, devices, acts or knowledge in this specification is included to explain the context of the invention. It should not be taken as an admission that any of the material formed part of the prior art base or the common general knowledge in the relevant art in Australia on or before the priority date of the claims herein. 5 Comprises/comprising and grammatical variations thereof when used in this specification are to be taken to specify the presence of stated features, integers, steps or components or groups thereof, but do not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof. 10 It would be desirable to produce a hermetically sealed capsule containing a substance to be extracted for producing beverages by injecting pressurized water into the capsule, which uses little material, and which gives the possibility of ensuring a high extraction level and with good reproducibility. 15 It is advantageous to produce a capsule having very good performances with different sizes, for example for substances to be extracted from 5 grams to 20 grams contained in the capsule, without any loss of performance. 20 It is advantageous to provide a capsule which may be manufactured in a mass production series with very low cost and which is very easy to package. It is advantageous to provide a capsule which may be easily treated after use, either for recycling or for producing energy by incineration. 25 In accordance with a first aspect of the present invention, there is provided a hermetically sealed capsule for preparing a beverage by injection of pressurized water, comprising a side wall, a bottom wall and an upper wall containing a hermetically sealed volume containing a substance to be extracted, the bottom wall and the side wall being in a 30 one-piece part forming a rigid or semi-rigid shell, a collar extending radially from one end of the side wall, the upper wall being in the form of a flexible membrane attached to the collar, the bottom wall being configured so as to be perforated by perforation spikes of a perforating plate when a certain water pressure is attained in the capsule, wherein the bottom wall comprises a central main portion intended to be perforated and an accordion 35 portion securely attaching the central main portion to the side wall, the accordion portion comprising one or several folds allowing the central portion to move towards the inside 3 and towards the outside of the capsule with an amplitude corresponding to an amplitude required for perforating the bottom wall without any lateral tension in the bottom wall, the diameter ratio between the bottom wall and the central main portion of the bottom wall being in the range between 0.6 and 0.8. 5 The central main portion of the bottom wall is, in position before use, positioned at a non-zero distance from a bottom line of the capsule. The distance between the central main portion of the bottom wall and the bottom line may advantageously be located between 0.2 and 1 mm. 10 The height of the accordion portion may advantageously be less than 8% of the height of the capsule. The height of the accordion portion may advantageously be located between 1 and 3 mm. The folds of the accordion portion may advantageously have portions with essentially circular or elliptical curvatures. The accordion portion may comprise a fold 15 oriented from a bottom line of the capsule towards the inside of the capsule and a second radially inner fold oriented towards the outside of the capsule. The collar may advantageously comprise an annular protrusion forming a radially inner area against which the upper wall is sealed, the protrusion being positioned radially 20 inside the radial periphery of the collar. The protrusion may have a height relatively to the area essentially equivalent to the thickness of the upper wall. A system for extracting a beverage by ejection of pressurized water in a capsule in accordance with the first aspect of the invention comprises an injection head configured 25 so as to bear against the upper wall, and a perforating and filtering plate intended to be bearing against the bottom wall and to perforate this bottom wall when the water attains a certain pressure in the capsule, the perforating and filtering plate and the capsule being configured so that the perforation spikes of the plate push the central main portion of the capsule towards the inside of the capsule when the capsule is set into place in the 30 system but before injecting pressurized water. The injection head may comprise spikes mounted on a convex surface, the injection head may further comprise a central channel for supplying water, the spikes positioned towards the outer periphery of the injection head being at a lower height than the height 35 of the spikes positioned towards the center.

3a In accordance with another aspect of the invention, there is provided a system for extracting a beverage by injecting pressurized water into a capsule containing a substance to be extracted, the system comprising an injection head configured to bear against an upper wall of the capsule, and a perforating and filtering plate configured to 5 bear against a bottom wall of the capsule and to perforate this bottom wall when the water attains a certain pressure in the capsule, the perforating and filtering plate and the capsule being configured so that the perforation spikes of the plate push the central main portion of the capsule towards the inside of the capsule when the capsule is placed into the system but before injecting pressurized water, wherein the injection head comprises 10 spikes mounted on a convex surface, the spikes that are positioned towards an outer periphery of the injection head being at a lower height than the height of the spikes positioned towards the center. The injection points positioned towards the periphery may be mounted on the protruding 15 bumps relatively to the convex surface. The injection head may comprise a ring-shaped elastic gasket configured so as to partly bear against the protrusion of the collar of the capsule. 20 THE REMAINDER OF THIS PAGE HAS BEEN INTENTIONALLY LEFT BLANK. THE NEXT PAGE IS PAGE 4.

Wu ZUZiUiiUtm F'11B2U1l1/053215 4 Other advantageous objects and aspects of the invention will become apparent from the claims or from the detailed description of an embodiment hereafter with reference to the appended figures, wherein: Fig. la is a perspective view of a capsule, showing the bottom wall, according to an 5 embodiment of the invention; Fig. lb is a sectional view of the capsule according to an embodiment of the invention; Fig. 1c is a detailed sectional view of a collar portion of the upper wall of the capsule according to the illustrated embodiment; 10 Fig. 2a is a perspective view of a perforating plate of an extraction system for capsules according to an embodiment of the invention; Fig. 2b is a planar view of the top of the perforating plate; Fig. 2c is a sectional view through the line 2c-2c of Fig. 2b; Fig. 3a is a perspective view of an injection head on an extraction system according 15 to an embodiment of the invention; Fig. 3b is an exploded perspective view of the injection head; Fig. 3c is a planar view of the top of the injection head; Fig. 3d is a sectional view of the injection head along the line 3d-3d of Fig. 3c; and Fig. 4 is a sectional view of a capsule in an extraction device before injection of 20 water. Referring first to Figs. la to 1c and 4, a hermetically sealed capsule for preparing beverages, notably hot beverages by injection of pressurized water, comprises a bottom or extraction wall 4, a side wall 2, a collar 10 and an upper or injection wall 6. The side wall 2 25 has a slightly conical shape and is entirely formed with the collar 10 and the bottom wall 4, forming a self-supporting shell. The walls 2, 4, 6 form a hermetically closed container partly or completely filled with a substance to be extracted, such as coffee grains, tea leaves, powdered milk, freeze-dried stock, or further other substances. The upper wall 6 is in the form of a sheet or a membrane in flexible material, advantageously in laminated multilayer 30 plastic material and optionally slightly tensioned attached to a collar 10. The upper membrane may advantageously be attached to the collar by welding, for example thermo-welding or ultrasonic welding. The collar preferably has a flat annular shape with a thickness (e) greater than the thickness of the side and bottom walls 2, 4, this in order to give some rigidity to the collar 10 which is intended to be clamped between drawers of an 35 injection head of an extraction appliance. The collar also provides stability and rigidity to the shell formed by the side and bottom walls.

WU ZU14/U11U' PCT/12111/053215 5 According to an advantageous aspect of the invention, the collar comprises an annular protrusion 12 defining an inner area 14, the protrusion 12 having a height relatively to the area 14 equal or essentially equal to the thickness of the upper membrane 6. The periphery 5 of the membrane 6 is housed in the area 14 as far as the annular protrusion 12. According to an aspect of the invention, the protrusion 12 is positioned at a certain radial distance (r) of the outer diameter 16 of the collar. This configuration gives the possibility of having a clean finish of the connection between the upper membrane and the collar, as well as an excellent seal with jaws of an injection head which sandwiches the collar. This gives the possibility of 10 supporting high injection pressures without any leaks and in a reproducible way, with low manufacturing cost of the capsules. The shell formed by the side wall, the bottom wall and the collar may advantageously be formed with injected plastic material or with a sheet in a thermoformed multilayer plastic 15 material (blow-molding). The shell may be entirely formed in plastic for example comprising polypropylene, but the invention also advantageously gives the possibility of forming the shell in a material other than plastic or in a combination of materials such as laminates comprising plastic. Notably, other materials which may be used for forming the shell within the scope of this invention are cellulose materials, i.e. materials formed with fibers similar to 20 the fibers used in the production of paper or cardboard. The cellulose material may give some rigidity and may be provided with a layer on the inner surface of the container in plastic material or with food wax, or even a very thin aluminum layer in order to guarantee the seal and reduce the diffusion of molecules through the wall. The cellulose fiber material may also be impregnated or mixed with other materials such as plastics for giving some 25 elasticity to the walls, this addition of materials may be locally distributed to the areas requiring some elastic displacement such as on the bottom wall or on portions of the bottom wall. In other words, by forming the side wall and the bottom wall in a mainly cellulose material or containing cellulose fibers or in other materials based on vegetable fibers, it is possible to have a composition of non-homogeneous materials, i.e. which vary according to 30 the position on the capsule. The bottom wall 4 is connected to the side wall 2 by a portion of rounded wedges 18 and comprises a central main portion 20 forming an extraction surface, and a peripheral annular accordion-shaped portion 22 entirely and securely attached with the side wall 2 by the 35 rounded wedge 18.

YVU 4U14/U1U) V1/iBJ2Ul1/U53215 6 The accordion-shaped annular portion 22 comprises at least one fold 24 oriented towards the inside of the capsule, i.e. forming a protrusion which enters the inside of the capsule from the bottom line 26, and preferably a second successive fold 28 radially inside the first fold 24 oriented in the opposite direction, i.e. towards the outside of the capsule. The folds 5 24 and 28 are preferably rounded with essentially circular or elliptical rounded portions, but other configurations may also be contemplated within the scope of this invention, for example folds with apices having a roundness with a small radius or a sharp angle. The rounded shape as illustrated is advantageous from the point of view of manufacturing since with it, it is possible to obtain very regular and reproducible wall thicknesses during 10 manufacturing with optimum elasticity and rigidity properties for the positioning and displacement of the bottom wall. The central or extraction portion 20 may advantageously have a larger thickness than the accordion portion 22 and is, depending on an embodiment, positioned at a small distance F 15 towards the inside of the capsule from the bottom line 26. The accordion area 22 allows the central portion 20 to elastically move towards the inside of the capsule or towards the outside. A significant advantage of this configuration is to allow the filling of the capsule as far as the collar if this is desired for the product to be extracted, to confine the contents with the upper membrane. The substance to be extracted may be slightly compressed inside the 20 capsule, the elasticity of the bottom wall and its capability of slightly moving due to the accordion portion allowing this filling in a highly controlled, regular and reproducible way. Such an optimum filling is not possible with a capsule having a completely flat bottom or a capsule having an only convex bottom since during the compacting of the substance in the shell during the manufacturing process, upon removing the press for placing the membrane, 25 it is not possible to avoid either having too much coffee when it decompresses or not having enough coffee for keeping it packed when there is no elastic adjustment of the capsule. The total height h of the accordion from apex to apex, may advantageously be of the order of 3 to 8% of the height H of the capsule, for example from 5 to 7% of the height H of the 30 capsule (i.e. the h/H ratio is of the order of 0.05 to 0.07), the distance between the bottom line 26 and the bottom of the central portion 20 being preferably less than 3% of the height of the capsule. In a suitable capsule for containing coffee grains for making a coffee of the espresso type, the height h of the accordion portion may be of the order of 1.5 to 2 mm and the distance f between the central portion of the bottom wall and the bottom line 26 being 35 less than 1 mm, for example between 0.3 and 0.7 mm. The central portion 20 preferably has vyU 14/t11:.U3 VUT/11I20111053215 7 a diameter d which is between 60 and 80% of the diameter D, of the bottom wall, i.e. the d/D ratio is greater than 0.6 and less than 0.8. Now also referring to Figs. 2a to 2c, 3a to 3c and 4, an appliance for extracting beverages, 5 for capsules, comprises a capsule holder into which the capsule is inserted for the extraction operation, the capsule holder having a perforating and filtering plate 30 against which the bottom wall of the capsule is positioned, and an injection head 32 which will be applied against the upper membrane of the capsule for injecting pressurized water into the capsule. The injection head comprises one or several ring-shaped gaskets 34a, 34b at its periphery 10 which are configured so as to press against the collar of the capsule. A gasket may notably be bearing against the protrusion 12 so as to be supported on either side of the protrusion on the periphery of the membrane and the radially outer side of the protrusion in order to produce a very good seal supporting the high injection pressures. It is also possible to have two ring-shaped gaskets 34a and 34b, radially positioned on either side of the periphery of 15 the upper membrane 6. The shape of the annular protrusion 12 on the collar of the capsule is an essential component of the direct seal (package seal) but also of the indirect seal (locking during extraction). Indeed, the triangular shape gives the possibility of triggering significant local 20 heating. The latter will generate an accurate and homogeneous weld. The weld creates a planar and regular area (shape of the weld head). The locking of the block compresses the injector gasket onto this interface area. In the illustrated embodiment, the injection head has a base body 38 with a slightly convex 25 supporting surface 35, a central channel 36 for supplying pressurized water and around the supply channel, distributed over the convex surface, a plurality of perforation spikes 37. In the illustrated embodiment, the perforation spikes are parts made separately or which are assembled in the base body 38 of the injection head 32. Advantageously, the height of the perforation spikes 37a positioned close to the water supply channel 36, i.e. towards the 30 center of the injection head, have a height slightly greater than the spikes 37b located towards the outer radial periphery of the injection head. The height difference between the spikes 37a radially towards the inside and the spikes 37b radially towards the outside is however less pronounced than the height difference due to the curvature of the convex surface 35 of the injection surface. For this purpose, the spikes 37 are made separately, 35 have identical shapes but are housed in holes 40 of the body 38 of the injection head at the desired height. In order that the radially outer spikes 37b may be raised relatively to the WO 2U12/U11053 PCT/IB2O1 1/053215 8 convex surface 35, around the hole 40, there are bumps 42 for anchoring the spikes at a raised height relatively to the convex surface 35. Elastic flexure of the upper membrane 6 towards the inside of the capsule when it is pressed 5 against the injection head is greater at the center than towards the radial edge, the convex shape of the surface of the injection head being adapted to the flexure of the membrane. In spite of the slightly smaller height of the peripheral spikes 37b relatively to the central spikes 37a, the radial position of the peripheral spikes 37b is configured so that they penetrate more into the membrane 6, taking into account its elastic flexure, than the central spikes 10 37a. This combined with the bumps 42 bearing upon the membrane gives the possibility of ensuring proper distribution of water towards the peripheral areas and ensuring a distribution of water flowing through the membrane and into the substance bed contained in the capsule with a homogeneous flow taking the curvature into account of the elastic membrane pressed against the substance inside the capsule. In this respect, after perforating the membrane 15 with the injection head, when the capsule is placed in the appliance, ready for use, the arrival of pressurized water through the central channel pushes the membrane towards the substance to be extracted towards the inside of the capsule and clears the membrane from the perforation spikes, the membrane acting as a pressure regulator. 20 When the capsule is placed in the appliance in the ready-for-use position, with the capsule holder closed, the perforation spikes 44 of the perforating and filtering plate 30 bear against the central portion 20 of the capsule and push it elastically towards the inside of the capsule. The capsule is configured with the perforating and filtering plate so that the bottom wall is bearing against the spikes 44 of the filtering plate before injection of water. An advantage of 25 the configuration of the bottom wall according to the invention is that the central portion 20 essentially moves parallel towards the inside so that it remains essentially planar upon bearing against the apices of the perforation spikes 44. When the pressurized water is injected into the capsule, at a certain pressure threshold, the central portion 20 of the bottom wall moves towards the bottom surface 46 of the filtering plate and the spikes 44 perforate 30 the bottom of the capsule in order to allow the beverage to flow through the channels 48 provided in the perforating and filtering plate 30. The accordion portion 22 of the bottom wall advantageously allows the displacement of the central portion 20 intended to be perforated, without their being any sideways tension so that there is no sideways tension on the bottom wall which would inhibit its uniform displacement towards the bottom of the perforating and 35 filtering plate. In other words, the central portion 20 of the bottom wall is free to move without any lateral stresses under the effect of the pressure uniformly distributed over the bottom so WU 2142/UI1Ui PCT/1132U11/053215 9 as to ensure very regular perforation over the whole central portion 20 intended to be perforated. This gives the possibility of ensuring a very homogeneous flow and well distributed in the substance bed contained in the capsule since the perforation of certain holes is avoided before the others which would generate lowering of pressure and formation 5 of preferential flow channels. Within the scope of the invention, it is possible to have an accordion portion which comprises more folds than in the illustrated embodiment. 10 The proportion ratio between the diameter on the left of the capsule is a significant element of the invention. The more the capsule is elongated, the more the extraction pressure (closely related to the flow rate) will be stable and high (optimum extraction). Actually, the injection distribution should limit to a maximum the preferential paths in order to provide extraction homogeneity. The distribution (size) of the particles also plays a role 15 The bottom wall of the capsule has a large deformation margin, which advantageously allows absorption and handling of the pressure factors during the packaging. The distribution of the twelve spikes of the filtering plate is also an advantageous aspect. 20 They are positioned preferably so as to represent four equilateral triangles. The pressure on the bottom of the capsule is homogeneous so as to obtain perforation under a specific and simultaneous pressure. For this, the thickness of the central main portion (20) intended to be perforated, is regular. 25 The capsule may further have an EVOH layer allowing substitution of the aluminum, it reduces molecular (oxygen) diffusion through the polypropylene multilayer.

Claims

1. A hermetically sealed capsule for preparing a beverage by injection of pressurized water, comprising a side wall, a bottom wall and an upper wall containing a hermetically sealed volume containing a substance to be extracted, the bottom wall and the side wall being in a one-piece part forming a rigid or semi-rigid shell, a collar extending radially from one end of the side wall, the upper wall being in the form of a flexible membrane attached to the collar, the bottom wall being configured so as to be perforated by perforation spikes of a perforating plate when a certain water pressure is attained in the capsule, wherein the bottom wall comprises a central main portion intended to be perforated and an accordion portion securely attaching the central main portion to the side wall, the accordion portion comprising one or several folds allowing the central portion to move towards the inside and towards the outside of the capsule with an amplitude corresponding to an amplitude required for perforating the bottom wall without any lateral tension in the bottom wall, the diameter ratio between the bottom wall and the central main portion of the bottom wall being in the range between 0.6 and 0.8.

2. The capsule according to claim 1, wherein a height of the accordion portion is less than 8% of the height of the capsule.

3. The capsule according to claims 1 and 2, wherein the central main portion of the bottom wall is essentially planar.

4. The capsule according to any one of claims 1 to 3, wherein the central main portion of the bottom wall is, in the position before use, positioned at a non-zero distance from a bottom line of the capsule.

5. The capsule according to claim 4, wherein the distance between the central main portion of the bottom wall and the bottom line is located between 0.2 and 1 mm.

6. The capsule according to any one of the preceding claims, wherein the height of the accordion portion is located between 1 and 3 mm.

7. The capsule according to any one of the preceding claims, wherein the folds of the accordion portion have essentially circular or elliptical curvature portions. 11

8. The capsule according to any one of the preceding claims, wherein the accordion portion comprises a fold oriented from a bottom line of the capsule towards the inside of the capsule and a second radially inner fold oriented towards the outside of the capsule.

9. The capsule according to any one of the preceding claims, wherein the collar comprises annular protrusions forming a radially inner area against which the upper wall is sealed, the protrusions being positioned radially inside the radial periphery of the collar.

10. The capsule according to any one of the preceding claims, wherein the protrusion has a height relatively to the area essentially equivalent to the thickness of the upper wall.

11. A system for extracting a beverage by injection of pressurized water comprising a capsule according to any one of the preceding claims, an injection head configured to bear against the upper wall, and a perforating and filtering plate configured to bear against the bottom wall and to perforate this bottom wall when the water attains a certain pressure in the capsule, the perforating and filtering plate and the capsule being configured so that the perforation spikes of the plate push the central main portion of the capsule towards the inside of the capsule when the capsule is placed into the system but before injecting pressurized water.

12. The system according to claim 11, wherein the injection head comprises spikes mounted on a convex surface, the spikes positioned towards the outer periphery of the injection head being at a lower height than the height of the spikes positioned towards the center.

13. A system for extracting a beverage by injecting pressurized water into a capsule containing a substance to be extracted, the system comprising an injection head configured to bear against an upper wall of the capsule, and a perforating and filtering plate configured to bear against a bottom wall of the capsule and to perforate this bottom wall when the water attains a certain pressure in the capsule, the perforating and filtering plate and the capsule being configured so that the perforation spikes of the plate push the central main portion of the capsule towards the inside of the capsule when the capsule is placed into the system but before injecting pressurized water, wherein the injection head comprises spikes mounted on a convex surface, the spikes that are 12 positioned towards an outer periphery of the injection head being at a lower height than the height of the spikes positioned towards the center.

14. The system according to any one of claims 11 to 13, wherein the injection spikes positioned towards the periphery are mounted on protruding bumps relatively to the convex surface.

15. The system according to any one of claims 11 to 14, wherein the injection head comprises a ring-shaped elastic gasket configured so as to partly bear against a protrusion of the collar of the capsule.

16. The system according to one of claims 11 to 15, wherein the injection head comprises a central water supply channel.

17. A hermetically sealed capsule for preparing a beverage by injection of pressurized water, substantially as hereinbefore described with reference to the accompanying drawings.

18. A system for extracting a beverage by injecting pressurized water into a capsule containing a substance to be extracted, substantially as hereinbefore described with reference to the accompanying drawings. MOCOFFEE AG WATERMARK PATENT AND TRADE MARKS ATTORNEYS P37069AU00