CAPSULE FOR PRODUCING A BEVERAGE AND METHOD FOR MANUFACTURING A CAPSULE

Abstract

Capsule (1) for use in a beverage preparation machine, said capsule comprising: a capsule body (2) defining a chamber (21), said capsule body comprising: one or more side walls (22), said walls extending axially towards a top opening (23), and a circumferential flange (24) that extends radially outward from the one or more side walls, and a top membrane (3) attached to at least a part of the upper surface (241) of the said circumferential flange and closing the top opening, and adapted to be punctured for liquid injection into the capsule, the top membrane and the flange extending globally along a common plane (P), and a bottom membrane (4), provided inside the chamber (21) so as to delimit between the top membrane (3) and said bottom membrane an ingredient chamber, and an opening device (5) provided inside the chamber and adapted to open the chamber.

Claims

1. A capsule for use in a beverage preparation machine, said capsule containing a soluble and/or extractable beverage ingredient, said capsule comprising: a capsule body defining a chamber, said capsule body comprising: one or more side walls, said walls extending axially towards a top opening, and a circumferential flange that extends radially outward from the one or more side walls, and a bottom beverage outlet, and a top membrane attached to at least a part of the upper surface of the said circumferential flange and closing the top opening, and adapted to be punctured for liquid injection into the capsule, the top membrane and the flange extending globally along a common plane, and a bottom membrane, provided inside the chamber so as to delimit between the top membrane and said bottom membrane an ingredient chamber, and an opening device provided inside the capsule body and adapted to open the ingredient chamber by relative engagement of said opening device with the bottom membrane under the effect of the liquid pressure increase in the ingredient chamber during injection of said liquid, wherein the upper surface of said flange comprises at least one circumferential transverse fixing section, said fixing section extending transversely to the common plane, and wherein the top membrane is attached at least to said fixing section.

2. A capsule according to claim 1, wherein the transverse fixing section can comprise at least one circumferential recess and/or at least one circumferential protrusion around the top opening.

3. A capsule according to claim 1, wherein the at least one circumferential transverse fixing section is positioned between the radially inward end of the flange and the radially outward end of the flange.

4. A capsule according to claim 1, wherein the at least one circumferential transverse fixing section extends by a length of at least 0.2 mm.

5. A capsule according to claim 1, wherein the at least one circumferential transverse fixing section extends by a width of at least 0.8 mm, preferably at most 2 mm, and is preferably comprised between 0.8 and 1.8 mm.

6. A capsule according to claim 1, wherein the at least one circumferential transverse fixing section comprises at least one radially inward end and at said radially inward end the circumferential transverse fixing section extends transversely to the common plane by an angle of at least 10, preferably at most 45.

7. A capsule according to claim 1, wherein the circumferential transverse fixing section comprises at least one recess, said recess extending transversely to the common plane and from the upper surface of the flange inside the flange, and wherein the bottom of the said recess presents a round concave shape.

8. A capsule according to claim 1, wherein a radially inward side and a radially outward side of said recess present straight surfaces.

9. A capsule according to claim 1, wherein the top membrane is fixed to the transverse fixing section by heat sealing.

10. The capsule according to claim 1, wherein the capsule body and the top membrane are made of the same recyclable plastic, such as polypropylene.

11. The capsule according to claim 1, wherein the capsule body and the top membrane are made of compostable and/or biodegradable material.

12. A method for manufacturing a capsule, said method comprising the steps of: providing a capsule body defining a chamber, said capsule body comprising: one or more side walls, said walls extending towards a top opening, and a circumferential flange that extends radially outward from the one or more side walls, said flange extending along a plane, and a bottom outlet, wherein an upper surface of said flange comprises at least one circumferential transverse fixing section, said fixing section extending transversely to the plane, introducing an opening device inside the capsule body, attaching a bottom membrane inside the capsule body and above the opening device, filling the capsule body with beverage ingredient, and fixing a top membrane to the upper surface of the flange of the capsule body by applying heat to the top membrane positioned along the flange with a heating die, wherein the heating die presents a shape complementary to the transverse fixing section of the flange and heats and presses the top membrane in the at least one transverse fixing section of the capsule.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0074] In the following, the invention is described exemplarily with reference to the enclosed figures, in which:

[0075] FIG. 1A shows a schematic cross-sectional view of a current existing capsule and FIG. 1B is a perspective cross-section view of an existing alternative embodiment,

[0076] FIG. 2A shows a schematic cross-sectional view of the upper part of a capsule according to a first preferred embodiment of the invention,

[0077] FIG. 2B is a magnified part of the recess in the flange of the capsule of FIG. 2A,

[0078] FIG. 3 shows a schematic cross-sectional view of the upper part of a capsule according to a second preferred embodiment of the invention,

[0079] FIG. 4 shows a schematic cross-sectional view of a capsule according to a third embodiment of the invention,

[0080] FIG. 5 shows a schematic cross-sectional view of a sealing die according to the first preferred embodiment of the invention,

[0081] FIG. 6 shows a schematic cross-sectional view of a sealing die according to the second preferred embodiment of the invention,

[0082] FIG. 7 shows a schematic cross-sectional view of the sealing die according to another embodiment of the invention,

[0083] FIG. 8 schematically shows a manufacturing method according to the invention.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

[0084] FIG. 1A illustrates an existing capsule 1 adapted for use in a beverage preparation machine. The capsule 1 comprises a capsule body 2 with one or more side walls 22 that extend axially from a bottom towards a top. The side walls extend towards a top opening 23. At the top opening 23, the body comprises a circumferential flange 24 that extends radially outward from the one or more side walls. The flange 24 is usually integrally formed with the one or more side walls 22. The flange preferably extends around the opening 23 in the form of a closed ring. The flange comprises an upper surface 241 facing the top and a lower surface. The lower surface preferably comprises, or consists of, a flat surface.

[0085] Generally, the transversal cross section of the body capsule is circular from the bottom to the top and the flange is circular too as illustrated in the perspective view of FIG. 1B.

[0086] The one or more side walls delimit a chamber 21 for containing a soluble and/or extractable beverage ingredient.

[0087] This soluble beverage ingredient is a water soluble powder ingredient and can be selected within the list of: instant coffee powder, milk powder, cream powder, instant tea powder, cocoa powder, soup powder, fruit powder or mixture of said powders. The powders can be agglomerated or sintered.

[0088] This beverage ingredient packed in the package can also be an ingredient able to be extracted or infused like a roast and ground coffee, or tea leaves. In that embodiment water extracts the beverage ingredient.

[0089] The capsule comprises a top membrane 3 that is fixed, sealed or attached to at least a part of the upper surface 241 of the circumferential flange and accordingly covers and closes the top opening 23. The top membrane 3 and the flange 24 extends globally along a common plane (P) corresponding to the plane of the top opening 23.

[0090] This top membrane is adapted to be punctured for liquid injection into the capsule. Preferably, the top membrane is pierceable by an injection needle of the beverage preparation machine which is adapted to inject an extraction liquid under pressure inside or into the chamber. Preferably, the puncturing operation is made at one single place by a water injection needle such as described in WO2006/082064 or WO2008/107281.

[0091] The term top membrane should be understood as the membrane which is pierced by the injection needle of machine, as opposed to the bottom membrane (such as described below) which should be understood as the membrane located on the opposite side of the capsule 1. This definition is such that top and bottom membranes are defined whatever the position of the capsule 1 within the machine, when both capsule and machine are engaged in a functional manner.

[0092] The capsule comprises a bottom membrane 4 that closes the bottom of the chamber 21. Accordingly, the soluble and/or extractable beverage ingredient is enclosed between the top and bottom membranes. The top and bottom membranes delimit an internal space of the chamber configured to hold the beverage ingredient for the preparation of a beverage.

[0093] In one preferred embodiment, a distributor wall 9 can extend through the internal cross section of the chamber defining an inferior sub-chamber for the ingredient and a superior distribution chamber for the liquid. This distributor wall comprises small holes to distribute liquid uniformly on the ingredient.

[0094] The capsule comprises an opening device 5 adapted to open the chamber by relative engagement with the bottom membrane 4 under the effect of the liquid pressure increase in the chamber during injection of said liquid. The opening device 5 may comprise a rigid plate comprising opening elements such as spikes on its surface turned upwardly towards the bottom membrane 4. The opening device 5 may be generally referred to as pyramid plate. Upon liquid injection inside the chamber 4, pressure builds up, which deforms the bottom membrane 4 against the opening means 5, until the bottom membrane is pierced, giving way to the beverage prepared inside the capsule 1 respectively chamber 21 below the opening device 5.

[0095] The capsule body comprises a bottom beverage outlet 25 at its bottom and below the opening device 5. The bottom of the capsule body preferably extends below the opening means to hold said opening means and collect the beverage to this beverage outlet 25 dispensing the beverage outside of the capsule 1, e.g. into a cup (not illustrated).

[0096] The top membrane 3 is fixed to the flange 24 in such a way that the extraction liquid injected into the chamber 21 effects a pressure increase therein and reaches the pressure necessary to obtain the piercing of the deformed bottom membrane 4 by the opening device 5. The top membrane 3 is thus fixed to the flange in such a way that it does not detach at least until a defined pressure inside of the chamber is achieved. This defined pressure may be at least 2 bars, preferably at least 3 bars or at least 6 bars. Thereby, the fixation effects that the capsule 1 does not leak via the interface between the flange and the top membrane during beverage preparation.

[0097] FIG. 2A shows a schematic cross-sectional view of the upper part of a capsule according to a first embodiment of the invention. The rest of the capsule is similar to the capsule of FIG. 1.

[0098] In this capsule, the upper surface 241 of said flange comprises a circumferential transverse fixing section 7 to which the top membrane 3 is attached. By circumferential, it is meant that this fixing extension is present on the whole circumference of the flange as represented on the left and right sides of the cross-sectional view. Preferably the membrane is fixed to said area by heat sealing, the membrane comprising a heat sealant component at its lower face facing the upper surface of the capsule flange.

[0099] The transverse fixing section extends transversely to the common plane P of the top membrane, the flange and the top opening. By transversely, it is meant that this fixing section is not in this plane P but extends in a direction that crosses said plane. As a result, at least a part 71 of the surface of said fixing section is inclined or slanted relatively to the plane P. FIG. 2B illustrates the slanted plane surface of the part 71 that forms and angle with the plane P at the radial inward end 73 of the fixing section.

[0100] Preferably, the circumferential transverse fixing section 7 extends by a length I of at least 0.2 mm. This length corresponds to the most important dimension of the transverse fixing section along the direction perpendicular to the common plane (P) as illustrated.

[0101] The flange may comprise one or more flat sections 6. Preferably, the upper part of the flange consists of the one or more flat parts 6 and the transverse fixing section 7. Each of the flat parts 6 comprises a flat surface, wherein these flat surfaces preferably extend along the plane P. One first flat part 6 is radially inward relative to the transverse fixing section 7 and the second flat part 6 is radially outward relative to said fixing section 7. Optionally, the top membrane 3 is not fixed to the one or more flat parts 6. Hence, the top membrane 3 may be fixed to the transverse fixing section 7 only.

[0102] According to this embodiment of FIG. 2A, the fixing section 7 is a recess extending transversely from the upper surface 241 of the flange inside the flange 24. As shown in FIG. 2A, the recess may have, in a cross-sectional view, two straight chamfers 71 surrounding a bottom concave rounded shape 72 The chamfers 71 and the concave shape 72 preferably extend around the whole circumference of the opening 23.

[0103] Hence, the top membrane 3 is fixed to the fixing section 7 in a very advantageous manner. This fixation in particular effects that the top membrane 3 is not fixed along the single plane P that covers the opening 6. Instead, the top membrane 3 is fixed along different directions provided by the parts 71 and 72. Accordingly, the strength needed to tear the fixation until it breaks or detaches is increased. In particular, when pressure increases inside the capsule due to the filling with water, said water exerts a force at the intersection 241a between the side wall 22 and the flange 24, said force pushing the membrane 3 upwardly and away from the flange 24 as illustrated by the arrow A. This force can facilitate the separation of the top membrane 3 from the flange along the flat part 6. Yet, at the transverse fixing section 7, the new orientation of this fixing section decreases the impact of the upwardly oriented force on the sealing of the membrane and the flange.

[0104] As shown in FIG. 2A, the fixing section 7 comprises a radially outward chamfer and a radially inward chamfer 71 and the top membrane 3 is fixed to both of them. In this way, the fixation between the flange and the top membrane is even further improved, because fixation between these parts is present in even further different directions.

[0105] The capsule is not limited to a specific material.

[0106] In one embodiment, the capsule body 2 is recyclable and/or consists of a single material, such as polypropylene. In particular, the capsule body 2 and the top membrane 3. Accordingly, these both elements can be sealed together strongly by heat sealing at a lower temperature by implementing the circumferential transverse fixing section 7.

[0107] In another embodiment, the capsule may be made of compostable and/or biodegradable materials, in particular the capsule body 2 and the top membrane 3. Accordingly, even if the sealing between the compostable and/or biodegradable materials of these both elements is weak, their attachment can be reinforced with circumferential transverse fixing section 7.

[0108] FIG. 3 exemplarily shows a capsule 1 according to a second embodiment of the invention. The capsule 1 corresponds to the embodiment of FIG. 2A except that the cross-section shape of the circumferential transverse fixing section 7 is different: the radially inward chamfer 71 is not present.

[0109] In other embodiments not illustrated, the recess 74 may be replaced by a protrusion. That is, the circumferential transverse fixing section extends transversely from the upper surface of the flange above the flange.

[0110] Instead of the recess receding relative to the upper surface of the flange extending along the plane P in FIGS. 2A and 3, the protrusion protrudes. This protrusion may comprise a shape that is complementary shaped to the shape of the recess illustrated in FIGS. 2A and 3. Preferably, the protrusion comprises a ridge, such as an annular ridge, that extends around the opening 6.

[0111] The upper surface of the flange can comprise a plurality of protrusions that are concentrically arranged relative to one another.

[0112] In one other embodiment not illustrated, the upper surface of the flange can comprise: [0113] at least one protrusion such as described above that extends transversely to the common plane P from the upper surface of the flange above the flange, and [0114] at least one recess such as described above that extends transversely inside the upper surface of the flange above the flange.

[0115] The protrusion(s) and recess(es) are concentrically arranged relative to one another.

[0116] FIG. 4 shows a schematic cross-sectional view of the upper part of a capsule according to a third embodiment of the invention.

[0117] The upper surface 241 of the flange comprises one circumferential transverse fixing section 7 that is transverse to the common plane P and that is positioned at the radially outward end 241b of the flange. The fixing section 7 consists in a plane chamfer 71 to which is attached the top membrane 3.

[0118] This embodiment is less preferred because generally during manufacturing, attaching the top membrane to the capsule body requires two different steps first to cut the membrane to the desired dimension and then to attach it to the recess 7.

[0119] FIG. 5 shows a cross section of a sealing die 100A used for manufacturing of the capsule illustrated in FIG. 2A. The sealing die 100A is adapted to seal and thus fix a top membrane to a fixing section of the flange of a capsule body. The sealing die 100A comprises an annular sealing section 170A configured to press and heat the membrane against the flange 241 of the capsule to fix the top membrane 3 to a fixing section of the flange of the capsule body.

[0120] The annular heating portion 170A of the sealing die presents a shape complementary to the circumferential transverse fixing section 7 of the flange of the capsule of FIG. 2A and an annular shape with a diameter such that the external surface of said portion 170A can be positioned along the external surface of the transverse fixing section of the capsule and so that the top membrane positioned between these surfaces can be attached along the whole surface of the transverse fixing section.

[0121] For this reason, the annular heating portion 170A presents a cross section comprising two chamfers 171 and an intermediate convex portion 172 corresponding to the negative shape or conformal shape of the two chamfers 71 and the concave shape 72 of the transverse fixing section 71 of the capsule of FIG. 2A.

[0122] By pressing the hot heating die on a top membrane 3 extending along the plane P defined by the capsule top opening and the flange of the capsule, the annular heating portion 170A enters inside the corresponding transverse fixing section 71 of the capsule and fixed it.

[0123] In a similar manner, FIG. 6 exemplarily shows a cross section of a sealing die 100B used for manufacturing the capsule illustrated in FIG. 3.

[0124] For this reason, the annular heating portion 170B presents a cross section comprising one chamfer 171 only and a convex portion 172 corresponding to the negative shape or conformal shape of the chamfer 71 and the concave shape 72 of the transverse fixing section 71 of the capsule of FIG. 3.

[0125] In a similar manner, FIG. 7 exemplarily shows a part of the cross section of a sealing die 100C used for manufacturing another type of capsule (not illustrated).

[0126] The annular heating portion 170C presents a cross section comprising one convex portion 172 and a plane portion 173 that is positioned radially outwardly.

[0127] The capsule to be sealed by a top membrane with this heating die 170 presents a flange comprising a groove corresponding to the negative shape or conformal shape of the annular heating portion 170C that is a concave rounded shape. The top membrane is sealed along this concave shape and along a plane portion extending along the plane P of the capsule and positioned at a radially outwardly part from the concave portion.

[0128] It is preferred that when a part of the top membrane is attached to the upper flat surface of the flange of a capsule, this part is attached to a portion of the flange that is radially outwardly positioned compared to the transverse fixing section.

[0129] In other embodiments, the annular heating portion 170A, 170B, 170C, which are protrusions, can be replaced by a recess. For example, the recess may comprise a shape that is complementary shaped to the shape of a protrusion at the upper surface of the flange of the capsule.

[0130] The above description with respect to protrusion thus applies analogously to the recess.

[0131] In FIG. 8, an exemplary manufacturing arrangement (e.g. a manufacturing line) that performs a preferred embodiment of a method for manufacturing a capsule 1 is shown. The capsule 1 may be the capsule of FIG. 2A or 3 described above. The manufacturing arrangement comprises at least a fixing device 100 such as one or more of the sealing dies 100A, 100B described above.

[0132] In a first step (a), a capsule body 2 is provided. Prior to step (a), the opening device 5, the bottom membrane and the beverage ingredient were introduced via the top opening. Further, a raw material 30 is provided between the capsule body 2 and the fixing device 100. The raw material 30 may be provided in the form of a foil. In the first step (a), the fixing device 100 is in an initial position.

[0133] In a second step (b), the fixing device 100 performs cutting and heat sealing of the top membrane to the fixing section 7 of the capsule body 2. The step of fixing may be performed by applying heat to the top membrane 3 that is contacted by the fixing device 100. In this way, the top membrane 3 is fixed to the fixing section 7.

[0134] Once the top membrane 3 is fixed to the fixing section 7, an advantageous fixation of the top membrane 8 to the fixing section 7 is achieved, as described above.

[0135] In a third step (c), which is optional, the fixing device 100 returns along the movement axis into its initial position. Thereby, a remainder of the raw material 20 remains and can subsequently move further to repeat steps (a) to (c) for manufacturing a further capsule 1.

EXAMPLES

[0136] In the following, examples with capsules according to the invention are described in comparison to comparative examples.

[0137] In each example, the resistance of the capsule to burst is measured. The procedure for such a measurement comprises the following steps: a) placing the capsule to be tested in a bell under airtight conditions; b) introducing compressed air (6 bars) inside the bell and through the hole at the bottom of the capsule and measuring pressure inside the bell; the tested capsule can be empty (no pyramid plate and no (aluminium) bottom membrane at the bottom of the body) or, if there are the pyramid plate and the (aluminium) bottom membrane, the air introduced through the bottom hole pierces easily the (aluminium) bottom membrane or wall; in both of these cases the results in terms of burst resistance of the top membrane are the same; and c) waiting for the bursting of the top membrane and measuring the corresponding pressure.

Example 1Comparative

[0138] The capsule according to this comparative example comprises a capsule body with a flat flange with a fixing section for the membrane. Hence, the fixing section does not comprise any parts that extend transversely relative to one another. Sealing of the top membrane to this fixing section is performed with heat at a temperature of 220 C. The top membrane is non-recyclable and has the layer structure PET/alu/PP. Burst pressure measurement is carried out on a series (number to be confirmed) of such capsules and provided the following results (the pressures indicate the pressures at which the capsules burst, i.e. at which the top membrane separates from the capsule body, resulting in leakage):

TABLE-US-00001 Type of Standard capsules Average deviation Min Max Choccocino 3.8 bar 0.23 3.21 bar 4.65 bar Caf au lait 3.8 bar 0.39 2.26 bar 4.66 bar

[0139] In order to be extracted correctly inside the beverage preparation machine (e.g. an NDG Nestl Dolce Gusto machine), the capsules preferably present a burst pressure of at least 2.1 bar for product extracted at low pressure and at least 3.0 bar for other products extracted at high pressure.

Example 2Comparative

[0140] The capsule according to this comparative example comprises a capsule body with a flat flange with a fixing section for the membrane. Hence, the fixing section does not comprise any parts that extend transversely relative to one another. Sealing of the top membrane to this fixing section is performed with heat at a temperature of 175 C. The top membrane is a recyclable multi-layer mono-material membrane made from PP. Burst pressure measurement is carried out on a series (number to be confirmed) of such capsules and provided the following results (the pressures indicate the pressures at which the capsules burst, i.e. at which the top membrane separates from the capsule body, resulting in leakage):

TABLE-US-00002 Type of Standard capsules Average deviation Min Max Choccocino 2.34 bar 0.4 1.49 bar 3.08 bar Caf au lait 2.56 bar 0.32 1.59 bar 3.02 bar

[0141] As can be derived from these results, the burst pressures are too low to enable the extraction of these capsules in the beverage machine. The membrane will delaminate during the beverage preparation.

Example 3According to the Invention

[0142] The capsule according to this example comprises a capsule body with a flange having a fixing section that comprises a recess as a groove and that has a symmetrical design such as illustrated in FIGS. 2A and 2B. Sealing of the top membrane to these parts is performed with heat at a temperature of 220 C. The top membrane is a non-recyclable membrane and has the layer structure PET/alu/PP sealed. Burst pressure measurement carried out on a series of such capsules and provided the following results (the pressures indicate the pressures at which the capsules burst, i.e. at which the top membrane separates from the capsule body, resulting in leakage):

TABLE-US-00003 Average Standard deviation Min Max 3.84 bar 0.34 3.08 bar 4.12 bar

[0143] As can be seen, the values of the burst pressures are comparable to the values of the comparative example 1.

Example 4According to the Invention

[0144] The capsule according to this example comprises a capsule body with a flange having a fixing section that comprises a recess as a groove with the same symmetrical design of example 3. Thus, the symmetrical design comprises a first part and a second part that are transverse relative to one another, and the top membrane is sealed and thus fixed to these parts. Sealing of the top membrane to these parts is performed with heat at a temperature of 175 C. The top membrane is a recyclable multi-layer mono-material PP membrane. Burst pressure measurement is carried out on a series of such capsules and provided the following results (the pressures indicate the pressures at which the capsules burst, i.e. at which the top membrane separates from the capsule body, resulting in leakage):

TABLE-US-00004 Average Standard deviation Min Max 2.73 0.50 2.21 3.50

[0145] As can be seen, the minimum values of the burst pressures increased and are always above 2.1 bar meaning a positive increase compared to the values of the same capsules with flat flange (comparative example 2).

Example 5According to the Invention

[0146] The capsule according to this comparative example comprises a capsule body with a flange having a fixing section that comprises a recess as a groove with an asymmetrical design such as illustrated in FIG. 3. Sealing of the top membrane to this fixing section is performed with heat at a temperature of 220 C. The top membrane is a non-recyclable membrane having the layer structure PET/alu/PP. Burst pressure measurement carried out on a series of such capsules and provided the following results (the pressures indicate the pressures at which the capsules burst, i.e. at which the top membrane separates from the capsule body, resulting in leakage):

TABLE-US-00005 Average Standard deviation Min Max 4.03 bar 0.21 3.45 bar 4.18 bar

[0147] As can be seen, the values of the burst pressures are improved compared to the values of the comparative example 1 which is the reference for having capsules working efficiently in the beverage machine.

Example 6According to the Invention

[0148] The capsule according to this example comprises a capsule body with a flange having a fixing section that comprises a recess as groove with the same asymmetrical design illustrated in FIG. 3. Sealing of the top membrane to this fixing section is performed with heat at a temperature of 175 C. The top membrane is a recyclable multilayer mono-material PP membrane. Burst pressure measurement is carried out on a series of such capsules and provided the following results (the pressures indicate the pressures at which the capsules burst, i.e. at which the top membrane separates from the capsule body, resulting in leakage):

TABLE-US-00006 Average Standard deviation Min Max 2.90 0.50 2.17 bar 3.55 bar

[0149] As can be seen, the minimum values of the burst pressures increased and are always above 2.1 bar in average meaning a positive increase compared to the values of the same capsules with a flat flange (comparative example 2).

Example 7Comparative

[0150] Capsules were produced with a capsule body made of a biodegradable material, namely polyhydroxyalkanoate (PHA), and a 120 micrometer top membrane made of PHA, too. The top membrane was fixed to an entirely flat fixing section of a flange of the capsule body. The average burst pressure was 8 bars.

Example 8According to the Invention

[0151] Capsules were produced with a capsule body made of polyhydroxyalkanoate (PHA) and a 120 micrometer top membrane made of PHA, too. The top membrane was fixed to a fixing section of a flange of the capsule body, which fixing section comprises an asymmetrical shape with a groove in the flange such as shown in FIG. 3. The average burst pressure was 10 bars.

[0152] Hence, the asymmetrical shape of the fixing section, to which the top membrane is fixed, effected that the burst pressure increased from an average of 8 bar in the comparative example 7 to an average up of 10.5 bars.

Example 9According to the Invention

[0153] Capsules were produced with a capsule body made of a biodegradable material, namely polyhydroxyalkanoate (PHA), and a 150 micrometer top membrane made of PHA, too. The top membrane was fixed to a fixing section of a flange of the capsule body, which fixing section comprises an asymmetrical shape with a groove in the flange such as shown in FIG. 3. Compared to example 8, the depth of the groove was changed from 2 mm to 0.5 mm. The average burst pressure increased from 10 bars to 11 bars.

[0154] It should be clear to a skilled person that the embodiments shown in the figures are only preferred embodiments, but that, however, also other designs of a capsule, sealing die and manufacturing arrangement for the method can be used.

[0155] List of references in the drawings: [0156] capsule 1 [0157] capsule body 2 [0158] chamber 21 [0159] side wall 22 [0160] top opening 23 [0161] flange 24 [0162] upper surface 241 [0163] radially inward end 241a [0164] radially outward end 241b [0165] beverage outlet 25 [0166] intersection 26 [0167] top membrane 3 [0168] raw material 30 [0169] bottom membrane 4 [0170] opening means 5 [0171] plane section 6 [0172] transverse fixing section 7 [0173] radially inward or outward surface 71 [0174] bottom surface portion 72 [0175] radial inward end 73 [0176] heating die 100A, 100B, 100C [0177] annular heating portion 170A, 170B, 170C [0178] chamfer 171 [0179] convex portion 172 [0180] plane portion 173 [0181] beverage ingredient 8 [0182] distributor wall 9