WO2023135137A1

WO2023135137A1 - Portion capsule

Info

Publication number: WO2023135137A1
Application number: PCT/EP2023/050461
Authority: WO
Inventors: Ralf MÜLLER
Original assignee: Tchibo Gmbh
Priority date: 2022-01-11
Filing date: 2023-01-10
Publication date: 2023-07-20
Also published as: EP4209431A1

Abstract

A portion capsule (1) filled with an extraction material for the production of a brewed product has, in a manner known per se, a main body made of plastic and a lid (3) fastened thereto. The main body forms a bottom region, a peripheral side wall and, adjoining the peripheral side wall towards a lid side, a peripheral main body collar. The lid has a lid collar whose inner side is welded to the main body collar in such a way that the main body collar and the lid collar jointly form a collar (4) of the capsule. The main body and lid together form a capsule which encloses the extraction material. The capsule has a substantially rectangular, in particular square, outline by virtue of the main body having, at least in the region of the collar, a substantially rectangular, in particular square, outline. The collar has, on the lid side, a plurality of ribs (50) which extend so as to be non-parallel to, that is to say at an angle to, the side wall.

Description

PORTION CAPSULE

The invention relates to the preparation of beverages or the like from an extraction material contained in a capsule, for example ground coffee. It relates in particular to a portion capsule.

Extraction devices for preparing beverages from an extraction material present in a portion pack are known, for example, as coffee, espresso or tea machines. In many corresponding systems, the portion packs are designed as capsules in which the extraction material is sealed, for example, in an airtight manner. For the extraction, the capsule is pierced on two opposite sides. A brewing liquid - generally hot water - is introduced on the first side. On the second side, the brewed product is discharged from the capsule. Depending on the drink to be prepared and the system, there must be quite a considerable pressure inside the capsule.

Coffee portion capsules are known from WO 2010/118543 and WO 2015/096989, which have approximately the shape of a cube, are made of plastic and, in contrast to the known cup-shaped capsules, do not have a circumferential collar at the level of one (top) cover surface. In the case of capsule systems according to the prior art, such a peripheral collar is required, among other things, for closing the capsule with a film serving as a lid. In contrast, a curved cover is used according to WO 2010/118543 and WO 2015/096989. The capsule produced according to the teaching of WO 2010/118543 therefore has a between the Cover surface defined planes circumferential, forming a collar welding brow, whose extension / lateral projection is significantly reduced compared to the collar of known capsules. An energy director is required for the welding, which is formed by a circumferential rib and which can be present on the cup (according to WO 2010/118543) or on the lid (according to WO 2015/096989). In the solution according to WO 2015/096989, the rib is formed by forming a circumferential groove (groove) on the cover from the top (i.e. the side opposite the side with the energy director), for example using a deep-drawing process. A circumferential groove is therefore formed on the capsule according to WO 2015/096989 for the purpose of forming the energy generator.

In particular, aluminum and plastics, for example polypropylene, have become known as capsule materials. So-called bio-plastics have also been discussed as capsule materials. On the one hand, this refers to plastics that are made from a renewable raw material (so-called bio-based plastics). On the other hand, bio-plastics are plastics that are biodegradable (so-called biodegradable plastics). The plastics proposed for the production of portion capsules are biodegradable and some contain a proportion of bio-based plastics.

In the present text, "biodegradable" means biodegradable according to the ENI 3432 standard (as of the end of 2020), and "bio-based" means "made from renewable raw materials, not on a fossil basis".

The available bioplastics, in particular biodegradable plastics, have the property that they soften at relatively low temperatures and therefore have a certain fluidity even at low temperatures (low glass transition temperature), but that they have to be heated to a fairly high degree before they are completely flowable (ie the melting temperature, as far as defined, is not particularly low). This poses special challenges when welding, since a transition to a very flowable state (if defined above the melting temperature) is a prerequisite for reliable welding, which is why the period of time during which the material is basically flowable is longer than with conventional plastics.

Plastic capsules of the type described in WO 2010/118543 and in WO 2015/096989 have proven themselves. However, their production is associated with a certain amount of effort. In addition, due to the sharp-edged ultrasonic tool to be used described in WO 2015/096989, it poses a certain challenge to adequately protect the diffusion barrier layer present in plastic capsules in the area of the weld.

It is therefore an object of the present invention to further improve the properties of capsules of this type, in particular with regard to manufacturability, and in particular with regard to their usability with different materials, including bioplastics.

This object is solved by the invention as defined in the claims.

A portion capsule filled with an extraction material for the production of a brewed product has, in a manner known per se, a base body made of plastic and a lid attached thereto. The base body forms a base area, a circumferential side wall and a cover side towards the circumferential Side wall adjoining all-round main body collar. The cover has a cover collar, the inside of which is welded to the base body collar, so that the base body collar and the cover collar together form a collar of the capsule. The body and lid together form a capsule that encloses the extraction material. The capsule has an essentially rectangular, in particular square outline, in that the base body has an essentially rectangular, in particular square outline, at least in the region of the collar. The collar has a plurality of ribs which do not run parallel, ie at an angle to the side wall, and which run on the cover side.

The ribs have the following function: they are used during torsional welding--torsional welding is a known method which does not need to be described in detail here--to engage a tool so that rotational oscillations of the cover relative to the base body are made possible. This applies regardless of whether the ribs are created by this tool or whether they are created in a separate step.

After the welding process, the ribs can contribute to the stability of the connection between the base body and the cover by structuring the weld. As a result, they have a stabilizing effect, in particular against shearing forces between the base body and the cover.

It turns out that the combination of such ribs with torsional welding firstly produces good welding strength with many plastic materials, with little material deformation. It is particularly advantageous that very different materials are available for the capsule, including bioplastics in particular. Second, any barrier layer remains intact. In plastic capsules, the barrier layer is a layer integrated into the wall, which increases the oxygen-tightness of the capsule compared to a structure made only of plastic (e.g. polypropylene or a bioplastic), which means that, for example, an oxygen-tight outer packaging of the capsule can be omitted. An example of a barrier layer material is EVOH (ethylene vinyl alcohol copolymer). Such a barrier layer can be integrated, for example, in the interior of the encapsulating material in the manner of a sandwich between layers of plastic. A conventional plastic welding process with an energy director can locally destroy the barrier layer at the site of the energy director. This disadvantage is avoided by the ribs and the torsional welding made possible thereby, the mentioned stabilizing effect, in particular with regard to shearing forces, nevertheless existing.

Thirdly, there are also other manufacturing advantages, including shorter welding times.

One finding underlying the invention is the stated advantages of the ribs in the collar, which are partly associated with torsional welding, especially with non-round but rectangular cross-sections, although torsional welding is associated with rotary movements (rotational oscillations).

The number of ribs can be selected as required, with a larger number generally being present, for example a total of at least 20 or at least 30, or at least 40 or else 60 and more. A maximum number can be 150 or 120 or 100, for example, due to the dimensions of the capsule. The width of the ribs and their spacing can be of a similar magnitude that that they form a rib and groove pattern. For example, the average distance between adjacent ribs may be less than or equal to five, four, or three times their average width, such that the width of the groove between the ribs is no more than four, three, or twice the width of the rib itself The relative dimensions of ribs and intervening grooves need not be constant along the circumference of the capsule, but may vary markedly, e.g Ribs that are about the same width as the grooves or markedly less wide midway between the corners.

As mentioned, the ribs run at an angle to the side wall and to the course of the collar, for example approximately perpendicular. The ribs can, for example, run approximately radially.

"Radial" and "axial" in this text always refers to the axis of the capsule, which runs centrally through the capsule and perpendicular to the plane defined by the collar (and generally also to the plane of the capsule base and a plane of the lid). This axis is also related to the function of the capsule: During brewing, the liquid flows axially, i.e. from the capsule base to the capsule lid (or vice versa).

The ribs can in particular run from the inside to the very outside of the collar, up to a radially outer edge.

The ribs are present on the collar on the cover side, i.e. they are formed in the cover collar. However, they can also cause the welding - i.e. the transition between the cover collar and base body collar, as far as still defined - itself gets a certain rib-groove pattern (wave pattern), so that in addition to the material connection there is also a certain interlocking, which contributes to the additional stabilization mentioned.

As is known per se from WO 2010/118543 and WO 2015/096989, the lid cannot be flat but curved outwards (relative to a capsule interior), i.e. axially outwards, i.e. an axial end lid surface is opposite that of the collar defined level offset axially outwards. According to these embodiments, the cover thus differs from a flat cover element, for example a foil or plate-like cover element. It is a three-dimensional shaped body. The cover can be produced in particular by deep drawing or alternatively by injection molding, which also applies to the base body.

In such embodiments, the shape of the lid can have, from the outside inward, the lid collar, a curved transition area and a central flat area which forms the actual upper-side cover surface. The transition area can, for example, be curved in an S-shape or run continuously curved from an outer part standing at an angle to the plane of the collar to the central flat area. In this case, the dimensioning is selected, for example, in such a way that the central flat area visually dominates, for example by being the same size as or only insignificantly (for example a maximum of 10%) smaller than the floor area. In particular, it can be provided that this flat area occupies more than 60% of the diameter and correspondingly at least 40% of the area.

The lid collar will generally form a peripheral surface facing the lid side—with the ribs if they are present on the lid side—which extends from an outer edge of the collar to a base of the bulge. It can be provided in embodiments that the approach of Bulge compared to the part of the base body side wall, to which the collar connects, is offset inwards. Such an offset can be at least 0.2 mm, for example.

In embodiments, the base body and/or cover can be present, for example, as a multi-layer system with bioplastic (e.g. Ecovio)/PVOH/bioplastic, with PVOH forming the diffusion barrier layer. In particular for thermoformable layer systems, a so-called tie layer, i.e. an adhesive layer, can also be arranged between the PVOH layer and the bioplastic, so that the structure can then be bioplastic/tie/PVOH/tie/bioplastic. Biodegradable tie layers are now known and available on the market, for example as natural waxes.

As an alternative to the design made of bioplastics, the base body and cover can also be made of another plastic, for example with a diffusion barrier layer, for example made of polypropylene.

The plastic material of the lid and that of the base body can be identical. However, it is also possible for the cover to consist of a plastic of a different composition, which can, however, be welded to the plastic of the base body.

A wall thickness in the area of the base body is in particular between 0.2 mm and 0.4 mm, for example between 0.25 mm and 0.35 mm. The same can also apply to the wall thickness of the lid. In one embodiment, the wall thickness of the lid corresponds approximately to the wall thickness of the base body. A special optional feature can be that the base body forms a thickening in the area of the transition between the circumferential side wall and the base body collar, which forms a bead that projects radially inwards. This serves to stiffen the collar area.

The capsule can--this applies to all embodiments, including the first aspect--be designed in particular in such a way that the base body and the lid together completely enclose the extraction material, without an opening covered by a foil or the like, for example. In particular, it can be hermetic and impermeable to oxygen, for example by having a suitable diffusion barrier.

Exemplary embodiments of the invention are described below with reference to drawings. In the drawings, the same reference numbers indicate the same or analogous elements. The drawings are not to scale and partially show corresponding elements in different sizes from figure to figure. Show it:

- Figure 1 shows a capsule;

- Figure 2 shows a base body for the production of a capsule according to Figure 1;

- Figure 3 shows a cover according to the prior art, drawn in section;

4 is a view of a capsule according to the invention; other

- Fig. 5 is a section through the capsule shown only partially, in the area of the weld.

The capsule 1 according to FIG. 1 essentially has the shape of a cube with rounded edges. However, the expansion increases slightly towards the upper side so that, strictly mathematically speaking, the capsule has the shape of a truncated pyramid. The angle of inclination of the lateral surfaces in the figure in relation to the perpendicular to the base surface 5 - meaning, of course, the plane perpendicular to the base surface that runs through the edge between the base surface and the corresponding lateral surface - is very small, it is preferably at most 2°, for example only about 1°. In addition, the height of the capsule above the base corresponds approximately to the length of the base edges.

The capsule has a body (or cup) 2 and a lid 3 attached thereto along a peripheral collar 4 . The base body forms a capsule base 5 and a peripheral side wall 6, which is closed off by the collar 4 at its outer end in relation to axial directions (axis 10), which is the upper end in the figure. The lid is curved outwards, in that the lid surface 9, which is essentially parallel to the capsule base 5, is offset outwards compared to the peripheral collar 4, ie upwards in FIG.

FIG. 2 shows the base body 2 (cup) before filling and before closing. The body collar 41 has an extent which may be greater than that of the collar 4 of the finished capsule.

FIG. 3 shows a cover 3 which—like the base body 2—is produced, for example, by deep-drawing or, for example, by injection molding. The lid has a substantially planar central area 31, a transitional area 32 forming a bulge, and a lid collar 42. Capsules of the type shown in FIG. 1, base body 2 of the type shown in FIG. 2 and cover 3 of the type shown in FIG. 3 are also already known from the prior art, for example from WO 2015/096990.

During the production of the capsule, the base body 2 is first filled with the extraction material and then the cover 3 is positioned. Ultrasonic welding then takes place, specifically torsional welding as is known per se from the prior art. Depending on the initial expansion of the base body collar and the cover collar, a protruding collar section can optionally be detached after the welding.

FIG. 4 shows an example of a capsule 1 according to the invention. It can be seen that the capsule has a plurality of ribs 50 with grooves 51 formed between them in the region of the collar 4 on the upper side—ie on the side of the cover collar. The ribs 50 are radial with respect to the axis 10 . Deviations from the radial direction are also conceivable—for example, the ribs 50 could each run parallel to one another on each of the four sides and perpendicular to the capsule side wall. In any case, the orientation of the ribs is not parallel to the circumferential direction (not locally parallel to the sidewall, i.e. at an angle to the plane defined locally by the sidewall at the location of the corresponding rib), nor parallel to the run of the collar. In particular, the ribs can each run from radially-inside to the radially-outer end of the collar.

The ribs may be arranged relatively close together as shown in Figure 4 so that their width and spacing are of a similar magnitude and they form a rib and groove pattern. For example, it can be provided that the distance between adjacent ribs (measured from their center) is not greater than Is four times or not more than three times its width. However, arrangements with ribs further apart are also conceivable.

FIG. 5 shows a schematic cross section through the capsule in the area of the collar (in the area shown in dashed lines in FIG. 1). The weld 70 between the base body 2 and the cover 3 is shown schematically by hatching. It can be seen in FIG. 5 that the diffusion barrier layer 70 is essentially intact up to the radially outer end (far left in FIG. 5).

In addition, the following optional features, which are advantageous for the stable connection between the base body and the cover, are shown in FIG. 5:

- The approach 12 of the curvature of the cover is compared to the outside of the peripheral side wall 6 offset radially -inside (offset v). The offset v is relevant in comparison to the thickness of the capsule wall; it is in particular at least 0.2 mm. The offset v is measured between the planes parallel to the outer surface of the base body in the area of the collar 4, which pass through the location of maximum concave curvature in the transition between the surface of the lid and the curvature of the lid or the outer surface of the base body.

- In the region of the transition between the circumferential side wall 6 and the base body collar 41, the base body forms a thickening 21, which forms a bead that projects radially inwards. - The material thickness of the base body is increased in the base body collar compared to the surrounding side wall 6, ie the base body collar is thicker than the side wall. This is also used for reinforcement.

Claims

PATENT CLAIMS Portion capsule (1) filled with an extraction material for the production of a brewed product, having

- A base body (2) made of plastic, with a base area (5), a peripheral side wall (6) and a peripheral base body collar adjoining the peripheral side wall towards a cover side

(41); and a lid (3) made of plastic, with a surrounding lid collar (42), the lid being attached to the base body by welding an inside of the lid collar to the base body collar, so that a common collar (4 ) trains;

- The base body and the cover enclosing the extraction material;

- wherein the base body (2) in the region of the collar (4) has a substantially rectangular cross-section;

- The collar (4) having a plurality of ribs (50) on an outside, characterized in that the ribs (50) run in the collar on the cover side. A portion capsule according to claim 1, wherein the ribs (50) extend at an angle to the side wall. Portion capsule according to Claim 2, in which the ribs (50) extend radially with respect to an axis (10) which is perpendicular to a plane in which the collar (4) extends. Portion capsule according to one of the preceding claims, wherein the ribs (50) extend to a radially outer end of the collar. Portion capsule according to one of the preceding claims, wherein the lid (3) forms a bulge such that the lid contributes to a capsule volume and a lid surface (9) is offset to the collar (4). Portion capsule according to claim 5, wherein the collar forms a peripheral surface (8) facing the lid side, which extends from an outer edge (7) of the collar (4) to a projection (12) of the curvature, the projection (12 ) of the curvature compared to a transition between the side wall (6) and the collar (4) is offset inwards. Portion capsule according to one of the preceding claims, in which the lid (3) is produced by deep-drawing. Portion capsule according to one of the preceding claims, in which the base body (2) is produced by deep-drawing. Portion capsule according to one of the preceding claims, in which the lid (3) and the base body (2) are made from the same plastic. - 16 - Portion capsule according to one of the preceding claims, wherein the cover (3) and / or the base body (2) are made of a biodegradable plastic. Portion capsule according to one of the preceding claims, wherein the cover (3) and the base body (2) has a diffusion barrier layer (70), for example

PVOH. Portion capsule according to one of the preceding claims, wherein the base body (2) forms a thickening (21) in the region of a transition between the peripheral side wall (6) and the base body collar (41), which forms a radially inwardly projecting bead. Portion capsule according to one of the preceding claims, wherein the number of ribs (50) is at least 20. Portion capsule according to one of the preceding claims, wherein a distance between two adjacent ribs (50) is not more than three times the average width of the ribs (50).