EP3556685A1 - Portion capsule - Google Patents

Abstract

A filter element (2) for a portion capsule can be inserted into a base element, for example a cup-like design, which defines an outer capsule wall together with a capsule cover attached to the base element after the filter element has been inserted. The filter element (2) is designed in such a way that it divides the interior of the capsule between an extraction material area and a collecting area which is formed between the filter element and the outer capsule wall. The filter element forms a filter plate (21) and a two-dimensional framework of struts (26) running along the filter plate and meeting one another at an angle, the struts having a cross-section that decreases radially outward.

Description

The invention relates to the field of systems for preparing beverages by means of liquid introduced into a beverage capsule. More particularly, it relates to a portion capsule containing a soluble food substance from which a beverage or beverage ingredient can be prepared by injecting water.

Among the systems for preparing beverages are the so-called coffee capsule systems (they are also available in variants for the preparation of tea) in which generally hot water is usually introduced under pressure into a capsule to prepare by extraction a coffee or tea beverage. For the introduction of hot water, the capsule is often pierced on one side (injection side). For discharging the brewed beverage, generally on the other side of the capsule (the extraction side), various possibilities are known. On the one hand, there are systems in which a piercing is provided by appropriate Perforationsdorne extraction side. On the other hand, systems are known in which an extraction-side boundary of the capsule is pierced or torn under the internal pressure during the brewing process, for which an external capsule (present in the brewing chamber of the corresponding coffee machine) or an internal capsule agent can be present. Finally, there are also capsules that are already open, so that no capsule wall / membrane has to be pierced or torn to dissipate the drink.

Among other things, to prevent unwanted coffee powder (or tea leaves) from entering the brewing beverage, capsules have become known in which a filter element is arranged in the interior of the capsule, which separates an extraction material region from a collection region and which is suitable liquid-permeable, for example, by having a plurality of filter openings.

Examples of portion capsules with such filter elements can be found for example in EP 1 344 722 as in WO 2010/085824 , The latter publication shows the filter element with supports which extend radially from an outer frame towards the center and thereby become thinner toward the center. These are intended to reinforce the filter element. Such a reinforcement may be indicated, in particular with regard to the preparation of brewed beverages under pressure, as is the case, for example, with espresso or other coffee with so-called "crema". In such brewing the capsule internal pressure rests to a large extent on the filter element, which therefore may also be exposed to mechanical deformation.

It is an object of the present invention to provide a filter element for a portion capsule and a corresponding portion capsule. The filter element should be mechanically stable and inexpensive and easy to manufacture.

According to one aspect of the invention, a filter element for a portion capsule is provided. This can be inserted into a, for example, cup-shaped base element, which defines an outer capsule wall together with a capsule lid attached to the base element after insertion of the filter element. The filter element is designed such that it divides the capsule interior between an extraction material region and a collecting region, which is formed between the filter element and the outer capsule wall. The filter element forms a filter plate and a two-dimensional framework of extending along the filter plate at an angle meeting struts.

This inventive approach is based on the finding that a two-dimensional framework generally brings more stability than a system of only radially outwardly inwardly extending supports. This may be due to the fact that under real conditions, the capsule internal pressure is not strictly constant in time and place, and therefore also bending vibrations of the filter plate may arise. A two-dimensional framework can absorb such comparatively better. However, the invention does not depend on any particular explanation for this finding.

The struts may have a radially-outwardly decreasing cross-section (i.e., a decreasing cross-sectional area).

Such a decrease in the cross-section of the struts may be a decrease in the extent perpendicular to the filter plate plane. The decrease of the cross section may be continuous to the outside. However, it is not excluded that the cross section in function of the radial position is also, for example, partially constant; on the average, however, the cross-section will be smaller further outward with respect to a center of the filter plate than further inside. It is also possible that the scaffolding of the struts is completely outwards, i. that the struts do not reach all the way to the outer edge of the filter element.

This preferred Ausrührungsform with outwardly decreasing cross-section is based on the finding that when a pressure in the capsule interior the concern Deformation is strongest in a central region of the filter element. In addition, generally less material is required for geometrical reasons when the struts have a larger inside cross-section than outside, compared to the inverted approach.

In a group of embodiments, the filter element has a central element. This can, for example, form a projection towards the interior of the capsule (towards the area of the extraction material); such a projection may be substantially conical. The framework of the struts then preferably extends to the central element, i. the innermost struts are connected to the central element to stabilize it. The central element can, for example, define a free space for an extraction-side piercing mandrel.

The framework of the struts can form a plurality of branches, in particular on a path formed by the struts, from the inside to the outside, so that struts arranged at least in a central region are respectively stabilized at both ends towards the sides.

The framework of the struts may in particular form a honeycomb structure. In such, the ratio between einzusetzendem material and stability is particularly favorable.

The filter plate may be provided in a conventional manner with filter openings which are regularly or irregularly distributed over the filter plate and allow passage of the liquid. The size of the filter openings may be such that a passage of extraction material is prevented. It is also not excluded the filter openings are spanned by, for example, a tissue-like filter material in order to prevent the passage of extraction material through the filter openings.

The struts may in particular be arranged on the side of the filter element for capsule interior, i. towards the extraction area. On the back side, the filter element can have a plurality of spacers which help to prevent the filter plate from being pressed against the outer capsule wall under a large internal capsule pressure.

The filter element can be made cup-like in a manner known per se by having a peripheral side wall adjoining the filter plate on the outside, in particular on the side of the extraction material, so that a filter cup volume forms part of the area of the extraction material. A circumferential sidewall may form a radially outwardly projecting circumferential flange which may serve to secure the filter element in a capsule base member (eg capsule cup).

In an alternative embodiment, the filter element as a whole is approximately disk-shaped, without circumferential side wall. Such a filter element is suitable, for example, for being fastened to a shoulder of the capsule base element (for example a capsule cup), for example by welding or another material connection. Alternatively, such a disk-shaped filter element can also be accommodated in a form-fitting manner - for example by clicking into a peripheral groove of the capsule base element - and / or non-positively in the capsule.

The invention also relates to a portion capsule with such a filter element. The filter element is within an outer capsule wall of the portion capsule arranged. Such may be formed by a cup-like base element and a cover attached thereto, for example. be formed. The base member generally defines a capsule bottom and a capsule sidewall. The filter element is located between the extraction material region filled with an extraction material, in particular coffee powder, and the capsule bottom or between the extraction material region and the capsule cover. The filter element can be fastened to the base element or possibly to the cover, or it can also merely be inserted into the base element and, for example, be stabilized by the material to be extracted relative to the base element. A possible attachment of the filter element to the base element or cover can be positive, non-positive and / or cohesive. Fasteners of filter elements in a capsule cup are known per se, and the present invention is independent of the way the filter element is mounted.

• Fig. 1 eine schematische Schnittdarstellung einer Portionenkapsel mit dem Filterelement;
• Fig. 2 eine Ansicht eines Filterelements von der Extraktionsgutseite her;
• Fig. 3 eine Ansicht des verkleinert dargestellten Filterelements von der gegenüberliegenden Seite (Sammelbereichseite) her;
• Fig. 4 eine Ansicht des Filterelements von Fig. 2 und 3 von oben;
• Fig. 5 eine Darstellung des Filterelements entlang der Ebene V-V in Fig. 4 geschnitten;
• Fig. 6 eine Darstellung des Filterelements entlang der Ebene VI-VI in Fig. 4 geschnitten; und
• Fig. 7 eine Ansicht eines alternativen Filterelements von der Extraktionsgutseite her.

Hereinafter, embodiments of the invention will be described with reference to figures. Show it:

• Fig. 1 a schematic sectional view of a portion capsule with the filter element;
• Fig. 2 a view of a filter element from the extraction material side;
• Fig. 3 a view of the reduced-size filter element from the opposite side (collection area side) forth;
• Fig. 4 a view of the filter element of FIGS. 2 and 3 from above;
• Fig. 5 a representation of the filter element along the plane VV in Fig. 4 cut;
• Fig. 6 a representation of the filter element along the plane VI-VI in Fig. 4 cut; and
• Fig. 7 a view of an alternative filter element from the extraction good side.

In the FIGS. 2, 3 . 7 and 4-6 different scales were used. In the figures, like reference characters designate like or analogous elements.

The capsule 1 according to FIG. 1 comprises a base member in the form of a cup 11 (with axis 20) and a cover 12 attached thereto along a peripheral flange 13, which together form an outer capsule wall and define a capsule interior. The cup 11 forms as known per se a slightly curved capsule bottom 14 and a circumferential side wall 15th

Cup and lid can be made of plastic in a conventional manner; However, on capsules made of other materials, such as aluminum, the invention is applicable. The attachment of the lid to the cup has also been made in a known manner, for example. By ultrasonic welding or possibly by gluing.

In the capsule interior, an inserted into the cup filter element 2 is present, the properties of which will be described in more detail below. In the illustrated embodiment, the cup is attached to a shoulder 16 formed by the circumferential side wall 15, for example, by welding, i. through a cohesive connection. Other attachment methods, including positive and non-positive connections, would also be possible.

The filter element separates an extraction material region 5, which will be filled with extraction material, from a collection region 6. In the exemplary embodiment shown, the filter element 2 is arranged in the vicinity of the capsule bottom 14, and the collection region 6 is located on the side of the capsule base. The injection of the water into the capsule for the brewing process then generally takes place from the lid side. The reverse arrangement would be conceivable in which the water is injected from the bottom and the filter element is arranged on the cover side.

FIG. 1 schematically and dashed represents an optional distribution element 3, which is also inserted into the capsule and which limits the Ausktionsgutbereich 5 to the injection side and between itself and the capsule cover 12 (or in the reverse arrangement between itself and the capsule bottom) defines a distribution region 7 ,

Both the filter element 2 and optionally the distribution element 3 is / are suitably liquid-permeable, in such a way that the extraction material can not pass.

The functioning of such filter elements as well as distribution elements is, for example, in EP 1 792 850 which publication is referred to in this regard.

In Figures 2-6 an embodiment of the filter element is shown. The filter element 2 forms a filter plate 21 with a plurality of filter openings 22 extending therethrough, which in the embodiment shown are slightly widening in the direction away from the area of the extraction material (towards the collection area side) in order to prevent clogging by small coffee grains. A plurality of spacers 29 are present on the collecting area side, which, in addition to the reinforcing scaffold described below, prevent the filter plate 21 from being pressed against the capsule bottom 14 under great internal capsule pressure and thus prevent flow in radial directions in the collecting area.

In the illustrated embodiment, the filter element is designed as a whole cup-like, with an outer side adjacent to the filter plate 21 circumferential side wall 23 which defines a Filterbechervolumen together with the filter plate, which is part of the Ausktionsgutbereichs. On the outside of the circumferential side wall 23, a flange-like outwardly projecting peripheral edge 24 is formed, which serves in the illustrated embodiment, the attachment of the filter element 2 in the capsule cup 11.

In the center of the filter plate 21, a central element 25 is formed, which has the shape of a projecting inward, that is to the extraction material region down protrusion. This protrusion forming the central member 25 is substantially conical with a plurality of protrusions.

On the extraction side of the filter plate 21, the filter element has a framework of struts 26 having a hexagonal structure, i. form a honeycomb structure. Such a structure is peculiar that the individual struts 26 each have the same length in bifurcations 27, so that each branch 27 has three struts 26 adjacent to it. Such a honeycomb structure forms a particularly stable two-dimensional framework.

Another property of honeycomb structures and other stable two-dimensional framework structures is that there will always be a plurality of branches on any path along the struts from radially outward to radially inward, i.e. there are no struts in the framework which extend from the outside to the very inside without being supported by a plurality of branches 27 also in lateral directions. The same applies to any path in the circumferential direction, i. it is impossible to find a path of struts around the whole circumference in the framework on which the struts do not branch in several places.

Radial-inside (directional information such as "radial" or "in the circumferential direction" or "central" refer in this text, unless otherwise stated, always on the axis 20 of the capsule) connects the framework to the central element.

The strength of the struts (ie the cross-sectional area perpendicular to the respective strut-course direction) decreases radially outward. This is realized in that the extent of the struts in the dimension perpendicular to the filter plate against radial-outside is gradually reduced, while the width, ie the extension perpendicular to the direction of the respective strut and parallel to the filter plate, is constant. The strength of the struts goes in the illustrated embodiment radially on the outside to zero, which is in FIGS. 5 and 6 looks very good. It would be but also possible that the strength is radially not very zeraususserst first, and that the struts extend to the circumferential side wall 23.

FIG. 7 shows an alternative embodiment of the filter element 2, which differs from that of Figures 2-6 in particular differs in that it has no circumferential side wall and is therefore not cup-shaped, but is disc-shaped as a whole. The edge region 28 of the filter element adjoins the filter plate 21 with the framework on the radial outer side. It can be on the outside (ie the side towards the collecting area, in Fig. 7 the underside and therefore not visible) have a circumferential rib which serves as energy directors in an ultrasonic welding process. The filter element can thus be welded to a shoulder formed by the capsule base element, which, for example, has a somewhat more pronounced design than that in FIG Fig. 1 schematically illustrated shoulder 16.

The central element, the framework of the struts 26 and the filter plate 21 in total are in the embodiment of Fig. 7 functionally identical to the embodiment described above.

Other embodiments are possible, including with other capsule shapes.

It would also be possible to remove the framework of the struts on the outside, i. on the side of the filter plate 21 to the collecting area to provide.

Example : It was carried out with a filter element according to Figures 2-6 performed numerical simulations. It was simulated that the filter element at a Temperature of 100 ° C is subjected to a pressure of 12 bar on the inside. For comparison, the same simulation was carried out on a filter element which does not have the framework of struts, but which is otherwise identical in design. It has been found that in both compared filter plates, the deformation in a central region, especially at the location of the central element and in its immediate vicinity, is strongest. However, the maximum deformation in the filter element according to the invention is reduced by about a factor of 3 in comparison to the filter element not designed according to the invention.

Claims (13)

Filter element (2) for a portion capsule (1) with base element (11) and capsule cover (12) which together define an outer capsule wall, which filter element (12) for the purpose of separating a collecting region (6) from an extraction material region (5) in a capsule interior Base element (11) can be inserted, wherein the filter element (2) has a liquid-permeable filter plate (21) and a plurality of along the filter plate (21) extending struts (26), characterized in that the struts (26) is a two-dimensional framework from below form an angle meeting struts (26). Filter element according to claim 1, wherein the struts have a according to the filter plate (21) radially-outwardly decreasing cross-section. Filter element according to claim 2, wherein the cross-section of the struts (26) decreases radially outwardly by the expansion perpendicular to the filter plate (21) decreases, while the width of the struts (26) is constant. Filter element according to one of the preceding claims, comprising a central element (25), wherein the framework of the struts extends to the central element and is connected thereto. Filter element according to claim 4, wherein the central element (25) is formed by a projection of the filter element to the extraction material region. Filter element according to one of the preceding claims, wherein the frame forms a honeycomb structure. Filter element according to one of the preceding claims, wherein the framework is present on a Ausktionsgutbereichseite the filter plate (21). Filter element according to claim 7, wherein a plurality of spacers (29) is arranged on a collecting region side of the filter plate (21) opposite the area of extraction area. Filter element according to one of the preceding claims, which is performed overall cup-like and has a side on the outside of the filter plate (21) adjoining the side wall (23). Portion capsule (1), comprising a cup-like base element (11) and a cover (12) connected thereto along a peripheral edge, wherein a filter element according to one of the preceding claims is inserted into the base element (1) and an extraction material region filled with an extraction material ( 5) separates from a collecting area (6). Portion capsule according to claim 10, wherein the filter element (2) is positively, materially and / or non-positively attached to the base member (11). Portion capsule according to claim 10 or 11, comprising a in the base member (11) inserted distribution element (3), which the extraction material region (5) to limited to an injection side and thus defines a distribution area (7) in the capsule interior. Portion capsule according to one of claims 10-12, wherein the base element (11) defines a capsule bottom (14) and a side wall (15), and wherein the filter element (2) is arranged between the capsule bottom (14) and the extraction material region (5).

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