Capsule and Device for Preparing Beverages and Method for Manufacturing a Capsule

Abstract

The invention relates to a capsule for use in a device for preparing beverages. The invention next relates to a method for manufacturing a capsule according to the invention. The invention further relates to an assembly of such a capsule and a device for preparing beverages.

Claims

1. A capsule for preparing beverages, comprising: an essentially closed housing which is at least partially filled with a substance to be extracted and/or dissolved, such as ground coffee, for preparing a beverage, wherein the housing is essentially closed, wherein the housing is defined at least by a peripheral wall, an end side connected to the peripheral wall, and a laterally protruding engaging edge connected to the peripheral wall at a distance from the end side in order to allow the capsule to be clamped into a capsule holder of a device for preparing beverages; and at least one essentially closed closing element connected to the laterally protruding engaging edge for sealing the substance into the capsule in order to preserve it, wherein at least a part of the closing element is composed of a laminated film comprising a plurality of polymer layers, which film comprises at least one polymer oxygen barrier layer, which barrier layer is essentially impermeable to oxygen, and which film comprises at least one polymer carrier layer connected to the oxygen barrier layer, wherein at least one carrier layer is provided with at least one weakened area.

2. The capsule according to claim 1, wherein the oxygen barrier layer is closed.

3. The capsule according to claim 2, wherein the oxygen barrier layer is not weakened.

4. The capsule according to claim 1, wherein a plurality of carrier layers of the film are weakened.

5. The capsule according to claim 4, wherein the weakened carrier layers are configured adjacent to one another.

6. The capsule according to claim 1, wherein the at least one weakened carrier layer is perforated.

7. The capsule according to claim 6, wherein the perforations are made in a pattern in the at least one weakened carrier layer.

8. The capsule according to claim 6, wherein the pattern is composed of a plurality of broken lines essentially oriented in parallel.

9. The capsule according to claim 6, wherein each perforation is elongated.

10. The capsule according to claim 1, wherein at least one weakened carrier layer faces toward the substance held in the housing.

11. The capsule according to claim 1, wherein the film is configured so as to tear as a result of pressure build-up in the capsule when water is injected into the capsule.

12. The capsule according to claim 1, wherein the film forms an outlet side of the capsule.

13. The capsule according to claim 1, wherein the end side of the housing forms an inlet side of the capsule.

14. The capsule according to claim 1, wherein the layers of the film are connected to one another in such a way that the film forms a composite.

15. The capsule according to claim 1, wherein at least two adjacent film layers are glued together.

16. The capsule according to claim 1, wherein the film is essentially fully compostable.

17. The capsule according to claim 1, wherein at least one carrier layer is composed of a non-woven fabric (non-woven) and/or a woven fabric (woven).

18. The capsule according to claim 1, wherein the layer composed of a non-woven fabric (non-woven) and/or a woven fabric (woven) is essentially impermeable to solid components of the substance enclosed in the capsule.

19. The capsule according to claim 17, wherein the carrier layer composed of a non-woven fabric and/or a woven fabric (woven) is composed of polylactic acid (PLA) and/or cellulose.

20. The capsule according to claim 1, wherein the oxygen barrier layer is at least partially composed of a material selected from the group composed of: polyvinyl alcohol (PVOH), polyvinylpyrrolidone (PVP), and polyvinyl acetate (PVAc).

21. The capsule according to claim 1, wherein the oxygen barrier layer is at least partially composed of an organic fraction (R), and an inorganic fraction, wherein the inorganic fraction preferably is composed of silicon alkoxide (Si(OR).sub.4).

22. The capsule according to claim 1, wherein the oxygen barrier layer is essentially impermeable to water vapour.

23. The capsule according to claim 1, wherein the film comprises at least one shielding layer connected to a side of the oxygen barrier layer facing away from the substance.

24. The capsule according to claim 23, wherein the shielding layer forms a moisture barrier layer.

25. The capsule according to claim 23, wherein the shielding layer is at least partially composed of cellulose.

26. The capsule according to claim 23, wherein the shielding layer is configured in a closed position.

27. The capsule according to claim 23, wherein the shielding layer functions as a carrier layer for the oxygen barrier.

28. The capsule according to claim 23, wherein the at least one surrounding material completely shields the oxygen barrier layer from an atmosphere surrounding the capsule.

29. The capsule according to claim 1, wherein the oxygen barrier layer is essentially fully enclosed by other layers of the film.

30. The capsule according to claim 1, wherein the capsule is at least partially composed of at least one bio-based material.

31. The capsule according to claim 1, wherein the closing element is glued to the housing, preferably by application of an essentially fully compostable glue.

32. The capsule according to claim 31, wherein the glue contains 1 to 70 wt % of a compostable polymer selected from the group composed of: an aliphatic or partially aromatic polyester and a thermoplastic aliphatic polyester urethane.

33. The capsule according to claim 1, wherein the housing is at least partially composed of polylactic acid (PLA) and/or cellulose.

34. The capsule according to claim 1, wherein the housing is composed of a laminate of a plurality of material layers, wherein at least one material layer is composed of an oxygen barrier layer.

35. The capsule according to claim 34, wherein the oxygen barrier layer is enclosed by at least two surrounding material layers.

36. The capsule according to claim 1, wherein the engaging edge is connected to an end of the peripheral wall facing away from the end side.

37. The capsule according to claim 1, wherein the peripheral wall has an essentially frustoconical design.

38. The capsule according to claim 1, wherein the housing is essentially rigid.

39. A closing element for use in a capsule, wherein at least a part of the closing element is composed of a laminated film, which film comprises at least one oxygen barrier layer, which barrier layer is essentially impermeable to oxygen, and which film comprises at least one carrier layer connected to the oxygen barrier layer, wherein at least one carrier layer is provided with at least one weakened area.

40. A method for manufacturing a capsule for preparing beverages, particularly a capsule, comprising the steps: A) manufacturing of a housing of the capsule from at least one preferably compostable material, wherein the housing is essentially closed, and wherein the housing is defined at least by a peripheral wall, an end side connected to the peripheral wall, and a laterally protruding engaging edge connected to the peripheral wall at a distance from the end side in order to allow the capsule to be clamped into a capsule holder of a device for preparing beverages; B) manufacturing of a laminated film, which film comprises at least one oxygen barrier layer, which oxygen barrier layer is essentially impermeable to oxygen, and which film comprises at least one carrier layer connected to the oxygen barrier layer, wherein at least one carrier layer is provided with at least one weakened area, and C) at least partial filling of the housing with a substance to be extracted and/or dissolved, such as ground coffee, for preparing a beverage; and D) connecting of the film to the housing in such a way that the substance is enclosed in the capsule in an essentially airtight manner.

41. The method according to claim 40, wherein the housing is manufactured during step A) by co-injecting various essentially compostable, liquefied materials into a mould, after which the housing is cooled to a temperature below the lowest melting temperature of the materials.

42. An assembly of a capsule according to claim 1 and a device for preparing beverages, which device comprises a capsule holder for holding the capsule.

43. The assembly according to claim 42, wherein the capsule holder comprises a plurality of holder parts which are moveable with respect to one another between an open position in which the capsule can be placed in the capsule holder and a closed position in which the engaging edge and the sealing element of the capsule are clamped in by the holder parts in an essentially fluid-impermeable manner.

44. The assembly according to claim 43, wherein the end side of the housing, when closed, is perforated by the capsule holder.

45. The assembly according to claim 44, wherein, when the capsule holder is closed, the film is perforated by the capsule holder as a result of pressure build-up in the capsule during injection of water into the housing.

46. (canceled)

Description

[0032] The invention will be explained by means of the non-limiting working examples depicted in the following figures. Specifically:

[0033] FIG. 1 shows a schematic depiction of a capsule according to the present invention,

[0034] FIG. 2 shows a perspective view of a capsule according to the invention,

[0035] FIG. 3 shows a cross section of the capsule according to FIG. 2,

[0036] FIG. 4 shows a detailed cross section of the capsule according to FIGS. 1 and 2,

[0037] FIG. 5 shows a detailed cross section of the film used in the capsule according to FIGS. 2-4,

[0038] FIG. 6 shows a view of a perforation pattern made in the film according to FIG. 5,

[0039] FIG. 7 shows a schematic depiction of a method for manufacturing a capsule according to the invention, and

[0040] FIG. 8 shows a schematic cross section of an alternative film for use as a closing element for a capsule according to the invention.

[0041] FIG. 1 shows a schematic view of a capsule (1) provided with a closing film (2). The film is composed of a laminate of various layers (3, 4, 5, 6). The first layer is composed of an open structure such as a non-woven fabric (non-woven) and/or a woven fabric (woven), in which openings are made to weaken it compared to a fully closed layer and thus facilitate tearing of the film. This layer (3) is for example composed of compostable PLA and has a thickness of for example 1 to 10 microns. The second layer (4) is composed of an adhesive layer (4), for example a PLA-based adhesive, in order to connect the first layer (3) to the third layer (5). The second layer (4) preferably has a thickness of approximately 2 microns. The third layer (5) is composed of a compostable barrier layer of PVOH in order to keep the ingredients in the capsule (1) fresh. The fourth layer (6) is composed of a carrier (6), which is composed of cellulose or PLA. This layer (6) has a thickness of between 20 and 50 microns. The carrier (6) comprises a plurality of weakened areas (7), which are made for example by means of a laser. The weakened area extends over approximately (two-thirds) of the thickness of the carrier (6). The first layer (3) can also function as a carrier layer.

[0042] FIG. 2 shows a perspective view of a capsule 11 according to the invention. FIG. 3 shows a cross section of the capsule 11 according to FIG. 1. The initially essentially closed capsule 11 comprises a housing 12, which has an essentially closed end side 12a, a frustoconical peripheral wall 12b adjacent to the end side 12a, and a laterally protruding engaging edge 12c (or flange) adjacent to the frustoconical peripheral wall 12b. This housing 12 is filled with coffee (not shown) and forms the basis of the capsule 11. The housing 12 is manufactured by co-injection technology, with the result that the housing 12 is composed of an (integrated) laminate of two material layers composed of PLA between which a material layer manufactured from PVOH is configured. This composition is fully compostable. Preferably, the PLA layers are in the amorphous state. The PLA layers fully enclose the PVOH layer. The PLA layers function specifically as a moisture barrier, while the PVOH layer functions as an oxygen barrier. An (under)side of the engaging edge 12c facing away from the end side 12a is connected to an essentially compostable film 13 in order to enclose the coffee in the housing 12 in an essentially medium-tight manner. An upper side of the engaging edge 12a is connected to a surface-mounted sealing ring 14 (see FIG. 4). The sealing ring 14 determines the maximum diameter of the capsule 11, as the latter protrudes with respect to the peripheral edge of the engaging edge 12c. The sealing ring 14 is composed of one or a plurality of additives, such as talc, including amorphous PLA, and is therefore essentially fully compostable. As shown in FIG. 4, the sealing ring 14 is fused by means of two concentric weld seams 15a, 15b to the engaging edge 12c. An innermost peripheral edge 14a of the sealing ring 14 is not connected to the housing 12 and extends out in an upward direction. An outermost peripheral edge 14b of the sealing ring 14 is also free and not connected to the engaging edge 12c. These free ends 14a, 14b facilitate positioning of the sealing ring 14 during clamping of the capsule 11 into a capsule holder, which is beneficial to the sealing capacity of the sealing ring 14. Between the free ends 14a, 14b, the sealing ring 14 is provided with a raised circular water-repellent edge 14c which further improves the sealing effect.

[0043] The film 13 closes off the housing 12 in an essentially airtight manner and is composed of an essentially fully compostable multi-layer composite, and is composed successively, as shown in FIG. 5, of a non-woven fabric (non-woven) 13a composed of PLA, a single-component glue layer 13b, an intermediate layer 13c at least partially composed of PLA, an oxygen barrier layer 13d composed of PVOH, a (two-component) glue layer 13e, and an outer layer 13f at least partially composed of cellulose having a thickness of about 14 microns. The non-woven fabric 13a, the intermediate layer 13c at least partially composed of PLA, and the outer layer at least partially composed of cellulose can be considered to be carrier layers. The three innermost layers, the non-woven layer 13a, the glue layer 13b, and the PLA layer 13c, are processed by means of an infrared laser, causing a hole pattern to be made (only) in these layers 13a-13c, which weakens them, with the result that the film 13 will tear more easily during use. The point or line-shaped perforations preferably have a thickness of 0.3 mm and are arranged in 11 rows, as also shown in FIG. 6. The outermost film layers, particularly the cellulose layer 13f and the oxygen barrier layer 13d, are not configured in a weakened manner and remain fully intact during the laser processing.

[0044] The non-woven fabric and/or woven fabric 13a preferably has a thickness of between 1 and 10 microns. The cellulose layer 13f is preferably between 20 and 50 microns thick, and more preferably between 30 and 40 microns thick. The intermediate PLA-based stiffening layer 13c is preferably about 20 microns thick. The oxygen barrier 13d is relatively thin, and is generally applied as a coating to an adjacent film layer, wherein the thickness of the oxygen barrier is preferably between 1 and 5 microns, and more preferably about 2 microns. The weakened areas therefore preferably extend over approximately half of the thickness of the film 13. In cases where a plurality of weakened areas is present, these areas can be applied in a pattern or randomly distributed over the carrier layer. For example, in order to allow the outflow of coffee over the entire surface of the film, the weakened areas should preferably also extend over the entire (outflow) surface of the film. This (outflow) surface is limited by the inner periphery of the engaging element 14.

[0045] The use of the capsule for preparing coffee can be described as follows. The capsule 1 is clamped into an opened capsule holder (not shown), after which the capsule holder is closed. During the closing of the capsule holder, the engaging edge 12c and the sealing ring 14 attached thereto are clamped in. During this clamping, the end side 12a is to be perforated by perforating elements of the capsule holder, and the sealing ring 14 manufactured from amorphous PLA is to partially form around a clamping edge of the capsule holder, thus creating a seal. After this, hot water having a temperature of about 95 C. is fed into the capsule holder, and via the end side 12a, into the capsule 11. This increase in pressure causes the film 13 to be deformed and, as a result of the weakened areas (perforations) made in the layers facing toward the coffee (13a-13c) of the film 13, to undergo controlled tearing on interaction with a perforation plate which is part of the capsule holder. By means of this perforation plate, the coffee can be caused to flow out of the capsule 11 and into the cup. During this extraction process, the sealing ring 14 will partially crystallise as a result of cold crystallisation into semi-crystalline form. Above the glass transition temperature (Tg) of PLA of about 55-60 C., moreover, the ring 14 will become somewhat rubbery, which improves the sealing effect. After the extraction process, the temperature of the sealing ring 14 will drop fairly quickly to below the aforementioned glass transition temperature, with the result that a relatively stiff, semi-crystalline sealing ring 14 is obtained. Because of the increased stiffness compared to its initial amorphous state, the sealing ring 14, and thus the capsule 11, can fairly easily be removed from the capsule holder.

[0046] FIG. 7 shows a schematic depiction of a method for manufacturing a capsule 20 according to the invention. In manufacturing the capsule 20, a laminated plastic film 21 is produced. The film 21 comprises a plurality of plastic-containing layers 21a-21f, which are described separately in the following.

[0047] An uppermost layer 21a, as shown in FIG. 7, is composed of a non-woven fabric (also referred to as non-woven or a web) or a woven fabric (also referred to as a woven). A non-woven fabric (non-woven) is a textile material that is neither woven nor knit. In this case, no yarn is used; rather, the material is directly layered into a non-woven fabric as a fibre or filament, and the layers are then attached to one another. In this case, the fibres or filaments may be oriented or non-oriented (oriented or non-oriented non-wovens). The structure may differ widely. It ranges from barely connected to very strongly connected, supple to stiff, and compact to highly voluminous. The fibres or filaments may be attached to one another by various methods, such as mechanical methods (fibres are crocheted or felted to one another using barbed needles), chemical methods (fibres are attached to one another using adhesives such as glue), or thermal methods (fibres are melted or fused with application of a glue or adhesive). The thickness of this non-woven fabric 21a may vary, but is preferably between 1 and 10 microns. The weight of the non-woven fabric is preferably between 10 and 30 grams per square meter. The tensile strength of the non-woven fabric, expressed as MD:CD ratio (wherein MD stands for machine direction and CD for cross direction) is preferably between 2.5 and 5. The non-woven fabric 21a is by nature an open or porous structure. The non-woven fabric 21a is preferably at least partially composed of an anisotropic polymer and/or a thermoplastic polymer, preferably a polyester, and more preferably polylactic acid (PLA). PLA is biodegradable in industrial composting facilities. Instead of a non-woven fabric 21a, a woven fabric may also be used.

[0048] A subsequent layer 21b is composed of a glue layer. A compostable adhesive is preferably used in this case. A suitable compostable adhesive is for example a pressure-sensitive adhesive (PSA) that contains poly(D,L-lactide-co-glycolide-co-c-caprolactone). Alternatively, one may use a terpolymer blend comprising poly(D,L-lactide-co-glycolide-co-c-caprolactone) together with another poly(D,L-lactide-co-glycolide-co-c-caprolactone) or together with a poly(D,L-lactide-co-glycolide-co-mPEG). Of course, conceivable alternative adhesives may also be used.

[0049] The third layer 21c relates to an intermediate polymer layer, preferably composed of a thermoplastic polymer, preferably a polyester, and more preferably polylactic acid (PLA) or polyethylene terephthalate (PET). The thickness of this intermediate polymer layer 21c is preferably between 10 and 30 microns, and in this working example is 20 microns.

[0050] A fourth layer 21d relates to an oxygen barrier layer. This layer is relatively thin and is preferably applied to the third layer 21c during the manufacturing process of the film 21, preferably by means of vapour deposition. Because of the low thickness, preferably between 1 and 5 microns, and more preferably about 2 microns, of the oxygen barrier layer 21d, one can also speak of a coating. The oxygen barrier layer 21d is preferably at least partially composed of a compostable material selected from the group composed of polyvinyl alcohol (PVOH), polyvinylpyrrolidone (PVP), and polyvinyl acetate (PVAc). PVOH is generally the most preferred of these substances, as PVOH can fairly easily be applied as a dense oxygen-impermeable film and has favourable adhesive properties. The oxygen barrier layer is preferably composed of a hybrid coating of an organic phase, for example formed by application of at least one of the aforementioned components, and an inorganic fraction which functions as a precursor. More preferably, the inorganic fraction is composed of silicon alkoxide (Si(OR)4), wherein R denotes an organic tail derived from one of the aforementioned organic molecules. Such hybrid coatings generally show particularly favourable compostability, and also show satisfactory oxygen impermeability. As a less environmentally-friendly alternative, the oxygen barrier layer can be composed for example of polyvinylidene chloride (PVdC), ethene vinyl alcohol (EVOH), or a metal oxide such as SiO.sub.2 or Al.sub.2O.sub.3.

[0051] A fifth layer 21e of the film 21 is composed of a glue layer, and is preferably composed of a compostable glue layer. An important component of this glue layer (adhesive layer) may be soybean flour, which is used for example in combination with phenol resin, or is mixed with casein- or sodium silicate-based adhesives.

[0052] The aforementioned adhesive layer 21e is applied in order to glue the oxygen barrier layer 21c to an outermost layer which is preferably composed of cellulose and/or PLA. The outermost layer 21e not only serves as a carrier layer which stiffens the film 21, but also shields the oxygen barrier layer 21c, making it possible to prevent damage to the oxygen barrier layer 21c. Moreover, this shielding leads to better preservation of the oxygen barrier layer 21c, as various oxygen barrier layers 21c are moisture-sensitive and disintegrate in a moist environment. By applying a moisture barrier layer 21e, such as for example cellulose or PLA, it becomes possible to keep the oxygen barrier layer 21c intact for a longer period of time, with the result that the substance can be preserved longer in the capsule.

[0053] The non-woven fabric 21a, the intermediate layer 21c, and the shielding underlayer 21f function as carrier layers for the oxygen barrier layer 21d.

[0054] After manufacturing the film 21, the film 21 is processed using an infrared laser 22 in such a way that the non-woven fabric 21a, the intermediate layer 21c, and the glue layer 21b between themalso referred to collectively as the top layerare perforated. The underlying layers 21d-21f are not exposed to the laser and thus remain intact, with the result that the film 21 is initially virtually impermeable to oxygen/gas. The laser 22 makes the perforations in the top layer 21a-21c in circular patterns 23, wherein each circular pattern 23 is composed of a plurality of broken lines arranged in parallel 24, wherein each line is composed of elongated perforations positioned at intervals from one another. In this case, the dimensioning of each perforation is particularly small, and they have a typical micron-order length and width. The interval between adjacent lines 24 is preferably between 0.1 and 2 millimetres. After the perforations have been made in the film 21, the film 21 is cut using a cutting element 25 such as for example another laser, a punch, or a knife in such a way that circular (disk-shaped) film parts are formed which are to function as a closing element 25 for a capsule.

[0055] After manufacturing of the closing element formed by the processed film 21, the closing element is to be applied to a housing 27 filled with ground coffee 26 (and/or some other beverage component). In this case, the housing 27 is cup-shaped and configured in an essentially shape-retaining manner. The housing 27 comprises a closed inlet side 28 (end side), a tapered side wall 29, and a laterally protruding flange 30 which functions as an engaging edge. A sealing ring 31 is applied to the side of the flange 30 facing toward the side wall 29. The ring 31 is preferably inseparably connected to the flange 30. A more detailed description of the housing 27 and the ring 30 applied thereto is described in international patent application number PCT/IB2014/002648 of the applicant, not pre-published, the contents of which are incorporated herein by reference as constituting part of the contents of the present patent. The film 21 is glued and/or welded to the flange 30, with the result that the coffee is packed into the capsule in an airtight manner. The film 21 is oriented in such a way that the perforated top layer faces toward the coffee 26. The film 21 functions as the outlet side of the capsule 27.

[0056] FIG. 8 shows a schematic cross section of an alternative film 40 for use as a closing element for a capsule according to the invention (not shown). The film 40 is essentially fully manufactured from plastic and is composed of three layers 40a, 40b, 40c. An uppermost layer 40a is composed of a damaged layer. The damage may be of various kinds, and may consist for example of a local decrease in layer thickness, one or a plurality of perforations, one or a plurality of roughened or torn surfaces, or a combination thereof. Because of the damage, the uppermost layer 40a is relatively weak and will tear fairly quickly when subjected to stress. The uppermost layer 40a may be composed of PLA, possibly enriched with one or a plurality of additives. The middle layer 40b is composed of a relatively thin oxygen barrier layer, for example manufacturedat least partiallyfrom PVOH. A lowermost layer 40c provides the film 40 with the desired stiffness. This lowermost layer 40c may, at least partly, be composed of PLA and/or cellulose. Both the uppermost layer 40a and the lowermost layer 40c play a role in directly or indirectly supporting the oxygen barrier 40b, and are therefore deemed to be carrier layers in the context of this patent. All of the layers are fused together under the effect of heat during a laminating process. Of course, glue may also be used if desired. As an alternative to the film 21 shown in FIG. 8, one may select a two-layer film, comprising a preferably moisture-impermeable oxygen barrier layer and a weakened carrier layer connected thereto. The carrier layer may form an inner side of the film, wherein the carrier layer faces toward a substance held by the capsule, but may also be configured on an outer side, wherein the oxygen barrier faces toward the substance held in the capsule and the carrier layer is not in direct contact with the aforementioned substance.

[0057] It will be apparent that the invention is not limited to the working examples shown and described herein, but that numerous variants are possible within the scope of the attached claims that will be obvious to a person skilled in the art.

[0058] The above-described inventive concepts are illustrated by several illustrative embodiments. It is conceivable that individual inventive concepts may be applied without, in so doing, also applying other details of the described example. It is not necessary to elaborate on examples of all conceivable combinations of the above-described inventive concepts, as a person skilled in the art will understand numerous inventive concepts can be (re)combined in order to arrive at a specific application.