Capsule containing a substance and method for its production

Abstract

 A capsule (1) containing a substance is made from two parts (2, 3) each having folds (10, 10' - 13, 13') made in the capsule parts made of preferably unstretchable sheet material. The folds are complementary, so that they interlock. In this way a stable capsule, preferably for ground coffee, can be made, even of paper or paper containing material.

Description

[0001] The invention relates to a capsule according to claim 1, to a method for its production according to claim 13 and a preferred use of the capsule according to claim 18.

[0002] Capsules containing a substance are known in different forms. In particular such capsules containing ground coffee are known that are made of deep drawn aluminum cups covered by a lid of sheet material. These capsules are water impermeable and are pierced in a coffee machine by piercing means for injecting water into the capsule and burst open when a certain pressure is reached. Such capsules can keep the ground coffee fresh for a certain time without further package around the capsule, but are regarded as problematic for the environment by some consumers due to the use of aluminum which needs considerable amounts of energy for its production. On the other hand, capsules are known that are made from two dish-like halves made of filter paper connected to a ring of cardboard, These capsules containing pressed ground coffee are water permeable and let the water run through the coffee rather freely, which is adverse to the perceived quality of the coffee extract. Further, an additional gas tight package is needed around this kind of capsules to keep the ground coffee fresh. The halves of thin filter paper forming the capsule together with the cardboard ring show many accidentally arranged overlapping folds or creases, respectively where the tin, porous filter paper is randomly folded during adapting its flat circular form to the wanted, dish-shaped form. The folds occur since paper will tear if stretched, so that the amount of paper used has to be large enough to form the dish shape, which will result in having to much paper in the circumferential edge regions.

[0003] The invention aims at providing a capsule, in particular for ground coffee, which avoids the disadvantages of the known capsules.

[0004] This goal is attained by a capsule as characterized by claim 1.

[0005] By the folded or creased edge regions, respectively, of the two halves, which are correspondingly creased and thus exhibit creased edge regions of the parts that match each other, it is possible to produce a stable capsule from two sheets only that can be made from a non-stretchable sheet. It is therefore possible and even preferred, to use paper or paper containing sheets, which can produce a capsule with good environmental properties. Due to the defined complementary creases or folds, respectively, strong thick paper - compared to the filter paper as known - can be used, so that a capsule can be made in this way from paper or paper containing material that is very stable and essentially water impermeable and can keep the ground coffee fresh for some time. Preferably the paper or paper containing sheet material is provided with thin layers of plastic material to make the capsule water and gas tight to a preferable extent. Even a thin layer of aluminum may be preferable, giving very good gas tightness even if a very thin layer is used that needs only a small fraction of the aluminum needed for the capsules made of aluminum.

[0006] The folds or creases can be shaped in many ways and can be easily provided for by an embossing procedure with a shaped punch and a corresponding die, which forms the parts of the capsule with corresponding creases, which then can be bonded to form the capsule enclosing the substance.

[0007] This method of manufacture for the capsule is defined by claim 13.

[0008] Preferably, the capsule is made essentially water tight as mentioned even if made of paper containing material and the capsule is provided thus for a coffee making process where the capsule has to be pierced to inject water and to extract liquid coffee therefrom. A coffee extracting device and system that works accordingly is described in the European Patent Application No. 01 107 800.3 which is hereby included in its entirety into the present specification as regards the piercing of the capsule described herein.

[0009] Now, preferred embodiments of the present invention are described with reference to the drawings wherein

Figure 1 shows a 3-D view of a preferred embodiment of a capsule;

Figure 2 shows a side view of the capsule of Figure 1; and

Figure 3 shows a top view upon the capsule of Figure 1.

[0010] Figures 1 to 3 show an example of a capsule 1 according to the invention. In this preferred embodiment, the capsule is made of two parts 2, 3 which are identical. Both parts 2, 3 are dish-shaped hollow pieces which enclose between them a space that contains a substance. A preferred embodiment is a capsule containing a dose of ground coffee, so that the capsule is intended to be used in a coffee machine to extract liquid coffee from this dose, as will be explained later. In this example, each part has a center section 14, which may be essentially flat, as shown, a rounded outer section 15 and an edge section 16, so that each part is dish-shaped.

[0011] The edge section 16 is provided with creases or folds respectively. In the shown embodiments only the creases 10 to 13 and 17 to 19 are provided with reference numerals. In this case the creases are separated from each other by flat zones of which only zones 5 to 9 and 20 are provided with reference numerals. It is as well possible to omit the flat zones so that the creases are directly adjacent to each other.

[0012] The creases 10 to 13 and 17 to 19 are provided on both parts 2, 3 in a complementary way so that the parts 2, 3 can be put together as shown so that each crease on one part can interlock with a complementary crease of the other part. In this example, each part 2, 3 has creases that are protruding in such a way that they extend outwardly i.e. creases 10, 12 and 18 of part 2 as seen in Figure 1 and creases that extend inwardly, i.e. creases 11, 13, 17 and 19 of part 2 as seen in Figure 1. Of course, on the other part 3, the creases are complementary, so that outwardly folded creases 10, 12, 18 of part 2 are met by inwardly extending complementary creases of part 3 and vice versa, which gives the shape of the shown capsule that has creases of alternating direction. The edge section of the capsule is thus formed by the two shaped sheets abutting on each other and has the double thickness of the sheet material.

[0013] The creases of the shown example extend into the curved section 15, which can be seen by the zones 10', 11', 12' and 13' of the creases, which extend like valleys (creases 11' and 13') or like ridges (creases 10', 12') into the rounded section 15 of part 2 of the capsule 1.

[0014] The shown preferred embodiment is only to be understood as an example. It can as well be, that the creases on the one part are all folded in the same direction, on the other part in the other direction. The flat zones between the creases can be less in number or can be omitted altogether. The creases can be larger on one part and smaller on the other, so that an asymmetrical capsule will be formed, but of course the creases of unequal size must be formed such that they are partly complementary such that a closed capsule can be made at all. Only one of the parts can be dish-shaped and the other can be an essentially flat lid, but having as well creases in the edge sections. The parts 2, 3 abut preferably directly as shown, but it is as well possible to have a third part that forms a center part on which the two creased parts abut. This center part needs to have a shape to interlock with the creases of the two other parts and would for the two parts 2, 3 shown in the drawings consist of a ring being on its one side shaped complementary to the creases of part 2 and on its other side complementary to the creases of part 3, which in this case need then not be complementary to each other, but can of course still be complementary to each other if such a ring is only inserted for some of the capsules to enlarge the volume of substance contained therein. The shown, rather angularly formed creases or folds, respectively, have to be understood as a preferred embodiment only. The creases may be provided as well in a more rounded shape, for example a wave-like shape. The number of such waves around the capsule may be equal, less or higher, respectively, than the number of shown folds, and of course the number of these angularly shaped folds may as well be less or higher than in the drawing. The different embodiments explained for these folds are as well applicable to folds of different shape, in particular to the wave-like shaped folds.

[0015] The creases or folds, respectively can be provided in a sheet material that can be stretched, for example aluminum or plastic, and accordingly can be deep drawn, but the folds are then rather beads formed into the sheet material. In this case they provide good stability of the capsule even if very thin sheet material is used.

[0016] It is preferred, however, to make the capsule from a sheet material that is not stretchable but will tear if a stretching force is applied, such as paper or paper containing material. In this preferred case, the folds or creases, respectively, are true folds wherein the flat, non stretchable sheet material is formed to a part for the capsule.

[0017] In any case, the creasing of folding, or beading is done in a controlled way by a tool, so that each part has the same folds, which leads to the shown and described interlocking of the creased parts and their abutting.

[0018] As said, preferred is a sheet material of paper or containing paper. It is preferred to provide rather thick paper, that can be regarded as water impermeable, at least if compared with filter paper. Of course, even comparably thick paper will let water soak through after a certain time, but this soaking through would not allow a useful extraction of a liquid from the substance in the capsule, for example liquid coffee extract from ground coffee enclosed in the capsule. In this sense, even a paper capsule can be described as water impermeable.

[0019] In a preferred embodiment, the paper of the capsule can be coated with layers of other materials. For example, on the side of the paper sheet material that will form the outside of the capsule, a plastic layer can be provided, that makes the capsule water impermeable from the outside.

[0020] On the other side of the paper sheet material, the side that faces the substance when the capsule is formed, a thin layer of aluminum or other material may be present. This layer makes the capsule essentially gas tight, allowing longer storage of the substance. For example if this is ground coffee it remains fresh longer if no oxygen can enter the capsule. An aluminum (or other material) layer or layers, respectively, can be provided as well on the outside of the capsule or only on the outside. Further, the plastic layer or layers, respectively, may be provided at the inside too or only at the inside. Any combination of such layers is possible.

[0021] Further it is preferred if on at least one side, better on both sides, of the sheet materials that face each other when the capsule is put together there is provided a heat bondable layer, for example a thin hotmelt layer or meltable lacquer, that can be melted temporarily, when the capsule parts are put and pressed together, so that these parts will be fixed to each other when the layer has cooled down.

[0022] The method of making the preferred capsule as shown or other capsules as described includes the steps of shaping the parts. This can be done in a tool having a die with the form of the dish and the folds or creases, respectively. A section of sheet material, in the preferred embodiment a circular patch of sheet material is then placed on the die and pressed by another punch or die with a form complementing the first die. If the sheet material is stretchable it will stretch during the process and will be provided with the beaded shape. If - as preferred - the sheet material is not stretchable, the section or patch of sheet material is oversized, so that excess material is provided to follow the form of the dies, so that the material is not stretched. In this case the dies promote the folding or creasing, respectively, into the shape with the folds or creases. Parts of the desired shape can be folded in this way. If the parts are identical in shape, as shown in the preferred example of Figures 1 to 3, the same dies can be used for both parts. Otherwise, different dies are used. The dies are driven by suitable driving means to exert the folding force on the sheet material.

[0023] Afterwards, the substance to be encapsulated by the capsule is placed on one of the parts, or more exactly into the hollow space of the first part which is to this end preferably inserted into another die of the same shape as the folding die. The substance can be placed into the part being already in a compacted shaped form or can be compacted on the part which is supported by the die. Compacting of the substance can also be done by closing the capsule in the following step. Afterwards, the second part is placed on the first part so that the creases abut on one another. A second die in the corresponding shape can then be pressed onto the capsule parts and they can be heat bonded by heating the dies in the edge regions. Another possibility is to apply a glue or adhesive to the edge sections of the parts before closing the capsule. If a liquid substance is to be filled into the capsule, an opening between the parts is left open, so that the otherwise closed capsule can be filled through the opening which is closed afterwards. A liquid filling can also be provided by placing a liquid filled plastic bag between the parts.

[0024] For extracting for example coffee from the capsule filled with ground coffee, it is preferred to use a coffee extracting device as described in detail in the European Patent Application No. 01 107 800.3 the contents of which is hereby enclosed by reference. Accordingly, the capsule will be inserted in an extraction chamber where the capsule is pierced upon closing of this chamber by water injection means on one side thereof and by extraction means on the other side thereof. Blocking means may prevent flowing out of extracted coffee until a predetermined pressure has been reached in the capsule. On the other hand it is possible that the capsule is pierced only by the water injecting means and bursts open under water pressure if deformed by water pressure such that piercing means are contacted by the capsule.

Claims

1. Capsule (1) containing a pulverulent or liquid substance, preferably ground coffee, characterized in that the capsule comprises parts (2, 3) defining between them a space containing the substance, and each having a creased edge section (16) with creases corresponding to the creases of the other part, so that the creased edge sections matchingly abut to each other, and that the parts are tightly connected to each other.

2. Capsule (1) according to claim 1, characterized that there are provided two parts that abut directly to each other, or that there is provided a center part to which the two part abut.

3. Capsule (1) according to claim 1 or 2, characterized in that the creases (10 - 13, 10' - 13') extend from the edge section into the space defining sections of the parts.

4. Capsule (1) according to any of claims 1 to 3, characterized in that the parts are dish-shaped.

5. Capsule (1) according to claim 4, characterized in that the dish-shaped parts include an essentially flat center section (14), a curved outer section (15) and the edge section (16), and that the creases reach from the edge section into the curved section.

6. Capsule (1) according to one of claims 1 to 5, characterized in that the creases of each part comprise creases protruding outwardly and creases extending inwardly.

7. Capsule (1) according to claim 6, characterized in that the creases are arranged alternatingly.

8. Capsule (1) according to one of claims 1 to 7, characterized in that flat zones are present between the creases.

9. Capsule (1) according to one of claims 1 to 8, characterized in that the capsule parts are made of essentially water impermeable material, and preferably are made of paper or a paper containing sheet material.

10. Capsule (1) according to claim 9, characterized in that the sheet is provided with an aluminum layer on its side facing the substance and/or on its outer side.

11. Capsule (1) according to claim 9 or 10, characterized in that the sheet material is provided with a layer for heat bonding of the parts.

12. Capsule (1) according to one of claims 9 to 11, characterized in that the sheet material is provided with a plastic layer on its side facing away from the substance and/or on its side facing the substance.

13. A method for manufacturing a capsule according to claims 1 to 12, characterized in that a first piece of sheet material is formed to provide a hollow part with a edge section folded in a defined manner, a second piece of sheet material is formed to provide a second part with a edge section folded in a defined manner, the first and second edge sections being matchingly folded, applying a dose of a substance within the hollow part on the first part, so that the complementary folded edge sections abut interlockingly on each other and bonding the parts together with their edge sections.

14. Method according to claim 13, characterized in that the second part is a hollow part as well.

15. Method according to claim 13 or 14, characterized in that the substance is ground coffee that is compacted before closing the capsule or by closing the capsule.

16. Method according to one of claims 13 to 15, characterized in that the parts are bonded together by heating a bonding film applied to at least one of the parts at least in the edge section, that bonds the parts together when cooled down.

17. Method according to one of claims 13 to 16, characterized in that the folds are angularly shaped and/or wave-like shaped.

18. Use of the capsule according to one of claims 1 to 12, containing ground coffee for making coffee in a coffee machine where the capsule is pierced to inject water therein and is pierced to extract liquid coffee therefrom.

Drawing