EP3362378B1

EP3362378B1 - Capsule containing a product to be extracted

Info

Publication number: EP3362378B1
Application number: EP16823059.7A
Authority: EP
Inventors: Marinus Barbara Arnoldus Maria Stas
Original assignee: STAS IP BV
Current assignee: STAS IP BV
Priority date: 2015-10-16
Filing date: 2016-10-17
Publication date: 2020-01-01
Anticipated expiration: 2036-10-17
Also published as: WO2017065615A1; EP3362378A1; NL2016510B1

Description

Field of the invention

The invention relates to a container containing a product to be extracted, more particularly coffee grounds or cut tea leaves, the container being provided with a plurality of walls, of which at least one wall portion comprises at least two layers of which a first layer carries a multitude of holes.

State of the art

A container of this type is known from WO2013/029184A . In this known container the second layer is not perforated. During use of this known container in a machine suitable for this use the container is pushed with the wall portion against a wall provided with draining holes which has, for example, a waffle-like structure. While the coffee is being prepared, a liquid is injected under high pressure into the container and the wall portion is pressed against the waffle-like structure as a result of the liquid pressure built up in the container, while the second layer is torn apart as a result of the liquid pressure and the perforations in the first layer form draining holes in the wall portion.

Summary of the invention

It is an object of the invention to provide a container of the type defined in the opening paragraph which is preferably completely or substantially completely made of biologically degradable fabric and with which a good extract can be prepared when used in the known machine. To this end the container according to the invention is characterized in that the first layer is made of a fabric that has a modulus of elasticity of more than 1500 N/mm² and the second layer is impermeable to liquid and made of a fabric that has a modulus of elasticity of less than 1000 N/mm². In the container according to the invention the second layer is completely impermeable to liquid. The two layers may be present on top of and free from each other or be locally attached to each other, for example, around the holes in the first layer. However, the two layers are preferably attached to each other over the entire surface. The second layer has for its object to avoid the tearing apart of the first layer around the holes, which would lead to too large holes being formed and the liquid passing through the container in too rapid a manner and too much pressure loss occurring so that less extraction would take place as a result of which the extract would be less tasteful. The holes are evenly distributed over the entire surface of the wall portion, so that distributed over the entire extraction surface holes will be formed during the process of preparation and the liquid will pass more fully through the entire product to be extracted. During use of the container in a machine fit for this purpose the liquid pressure will tear open the foil to a minimum extent so that the pressure will hardly diminish and just enough liquid will flow through the foil.
The first layer is preferably made of a fabric that has a modulus of elasticity that exceeds 2000 N/mm². It is even more preferable for the first layer to be made of a fabric that has a modulus of elasticity that exceeds 3000 N/ N/mm².
The first layer is preferably made of a hard crispy or rigid polylactide. Polylactide (PLA) has a modulus of elasticity of 3500 N/ N/mm².
An embodiment of the container according to the invention is characterized in that the first, least elastic, layer is located on the outside of the container. During the preparation of an extract, liquid is fed under pressure to the container. The second, more elastic, layer will be presssed through the holes under the influence of the pressure of the liquid and form bulges on the outside of the first layer, which bulges will tear open or break at a certain pressure. The breaking of the stretchable layer nearly always occurs within the holes of the first layer in the centre of the hole. If the rims of the holes are not sharp but rounded, the second layer will tear open or break less rapidly at another spot (for example at the rim of the holes) and thus a higher pressure can be built up until draining holes are formed in the second layer, which is beneficial to the extraction process.
The holes in the first layer are small and are preferably made by means of a laser. This is a relatively expensive method for making holes. An advantageous embodiment of the container according to the invention is characterized in that the first layer is made of woven yarns while the holes are made among the yarns. By utilizing a relatively cost-effective woven fabric for the hole-containing first layer, there is no longer a need to make holes. The desired size of the holes in the first layer can be simply obtained by selecting or manufacturing a suitable woven fabric having the proper inter-yarn distance and thickness of the yarns. The woven filament fabric may also be flattened, for example by means of a heated flattener, so that filaments are deformed from egg-shaped to flat and the holes in the woven fabric become smaller.
The second layer is preferably made of a fabric that can stretch out to at least one and a half times its length at room temperature before it tears open. As a result, first a sufficient amount of pressure will be built up in the container to obtain a good extract and after this the tearing open of the second layer will take place in a predictable manner. It is more preferable that the second layer is made of a fabric that can stretch out to at least twice its length at room temperature before it tears open.
The second layer is preferably made of polyethylene. Polyethylene (PE) has a modulus of elasticity ranging between 100 and 900 N/mm². The second layer may also be mainly starch, or a layer based on natural oil, starch and PLA or be formed substantially from latex, rubber or an elastic polymer (TPE).
An embodiment of the container according to the invention is characterized in that the second layer weakens at a lower temperature than the first layer.
A further embodiment of the container according to the invention is characterized in that the second layer is thinner than the first layer. The first layer is for example in essence formed from a biopolyester PLA or chitosan.
The second layer is preferably provided with a moisture and oxygen barrier for a better conservation of the contents of the container so that their quality is retained for an extended period of time. In lieu of this, or supplemental to this, preferably an additional moisture and/or oxygen barrier layer is present between the first and second layer. Furthermore, in lieu of one or both measures stated above or supplemental to one or both measures, fluorine may be applied by vaporization preferably to the first and/or second layer by means of fluorination.
Yet a further embodiment of the container according to the invention is characterized in that the wall portion mentioned above further includes a third layer of filtering material. The elastic second layer may then be located between the third layer of filtering material and the first layer bearing holes. The elastic second layer may also be located on both sides of the first layer. The filtering material may be a woven but also a non-woven filament fabric. The first layer may be made of for example plastic, paper or aluminium. Since the second layer is attached to filtering material (for example sealed to it), a slightly fibre-strengthened structure is obtained as a result of which the three layers together are so strong that they do not completely adopt the waffle structure of the wall, so that the liquid during extraction sees its way to reach various draining holes while sufficiently high pressure is retained, so that a proper extract with foam is prepared. At the same time the filtering material stops the particles (for example coffee particles) which otherwise start clogging before the holes and may lead to blockages. The sheet of filtering material may in connection with a better sealing of the container have a smaller diameter than the two other layers, so that the filaments do not form holes in the seal or glue layer at the flange.
A further embodiment of the container according to the invention is characterized in that the distance between the holes is situated between 1 and 3 mm. The first and second layers may be attached to each other, for example by means of heat sealing or gluing. In the case of a liquid/gel-formed glue, the glue is preferably applied in a very thin layer. The foil layers are pressed together after the layer of glue has been applied. In that case the foil formed by the two layers is stretched out the most at the side walls of the protuberances of the waffle structure on the hole-carrying plate the container is pressed against during use of the container in a machine intended for extracting the product present in the container. By providing not too large distances between the holes, a hole-carrying zone of the first foil layer will be present at all or at any rate most of the side walls. Since the foil is stretched out the most here, the second layer will thus bulge the most here as a result of the pressure of the liquid and break open the first, which is advantageous for obtaining a good/optimal extraction process. When smaller distances are selected the foil is to cope with too much heat during the lasering process so that it deforms. When larger distances are selected the passing time of the water and the quantity of coffee in the extract start to be more variable and coffee is obtained of a less constant quality. If the holes in the first layer have sharp rims on one side, this may facilitate the breaking of the second layer when pressing the liquid through the hole.
Again a further embodiment of the container according to the invention is characterized in that the largest size of the holes is situated between 20 and 200 micrometers. The size of the holes is dependent on the thicknesses of the layers. These sizes too are optimal for obtaining a good/optimal extraction process.
The container may be a pad which is formed by two rigid walls which are attached to each other along the circumference, where at least one of the walls forms said wall portion. These two walls are preferably sealed together. At the location of the seal these two walls are preferably not provided with holes so as to avoid holes evolving from the sealing process so that no liquid density and/or air density is available any more.
The container may be formed like a cylinder or a truncated cone having a round side wall and two end walls, where at least one of the end walls comprises said wall portion.
In this case the remaining walls of the container may each also comprise a layer of filtering material. In this case the container is first to be inserted into a container basket that has a rigid side wall and a flange projecting outwards in radial direction, so as to avoid liquid easily flowing to the draining holes via the porous side wall along the outside of the container, as a result of which insufficient pressure is built up for obtaining a good extract.
In this embodiment a plastic foil having local holes in one of the layers is attached preferably also on the other end wall. In consequence, it does not matter with which end wall to the front the container is inserted into the container basket and thus it is impossible to insert the container into the container basket in the wrong way. One of the foils will then be the first to contact hot water from outside as a result of which this foil weakens and then allows water to pass through the holes. In situations where the foil does not allow water to pass on the inlet side, the water will pass the foil. This does not affect the extraction process because on the inlet side the pressing together of the contents (coffee/tea) is not as strong as on the outlet side. Subsequently, pressure is built up in the container and the other foil is pressed against the waffle structure as has already been described above. The one foil layer then operates as a press-down foil and will exert a steady pressure.
The remaining walls may also be made of rigid water impermeable fabric and form a cup open at an end side, where the side wall rim bordering on the open end side is provided with an outward projecting flange to which the sheet of filtering material accommodating the foil that has local holes is attached and closes the open end side. The side wall and this end wall are preferably self-supporting. Also in this embodiment he foil is preferably sealed to the flange, where preferably at the location of the seal the foil does not have holes, again so as to avoid that holes arise during the sealing process, so that no liquid density and/or air density is available any more.
In this embodiment the side wall and end wall of the container are preferably made of oxygen impermeable fabric and the sheet of filtering material covered by the foil having local holes is provided by means of an oxygen impermeable barrier layer.This barrier layer may be present on the sheet of filtering material or on the foil or in between the foil and the sheet of filtering material and may be a separate sheet or be formed by a coating, for example polyvinyl alcohol, SiOx (silicon oxide), or ORMOCER®, the latter being an anorganic organic hybrid polymer (brand name of the Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. Munich). This barrier layer may also be a metallized biologically degradable compostable foil or a wafer thin biologically degradable compostable foil having barrier properties. This barrier layer lengthens preservability and this cup need not be packed in oxygen impermeable packaging. The container may be made of a biologically degradable compostable material, where the side wall and end wall are provided with an oxygen impermeable layer or coating, for example polyvinyl alcohol or fluoride. An oxygen impermeable layer for lengthened preservability may also be formed by polymerisation under vacuum where the surface is densified. The container may also be an injection moulded product or thermoform product and is metallized (for example application by vaporization) on the inside and/or outside with a thin metal layer (for example aluminium) and finished with an oxygen impermeable layer (for example polyvinyl alcohol) or a biologically tinted varnish layer. In addition to an oxygen barrier this has also an attractive and recognizable appearance as a result of which the user can see that he takes the right capsule.

Brief description of the drawings

The invention will be further explained below while reference is made to the examples of embodiment shown in the appended drawings of the container according to the invention, in which:

Fig. 1 shows a first embodiment of the container according to the invention together with a sectional view of a container basket;
Fig. 2 gives a sectional view of a second embodiment of the container according to the invention;
Fig. 3 gives a sectional view of a first embodiment of the wall portion constituted by two layers that have a different modulus of elasticity of the container shown in Fig. 1;
Fig. 4 shows the wall portion shown in Fig. 3 during use in a machine;
Fig. 5 gives a sectional view of a second embodiment of the wall portion constituted by two layers that have a different modulus of elasticity of the container shown in Fig. 1 during use in a machine;
Fig. 6 gives a top view of the wall portion shown in Fig. 5;
Fig. 7 shows the embodiment shown in Fig. 1 during use in a machine suitable for this purpose;
Fig. 8 shows a waffle-iron-shaped discharge cap of a known machine for extracting the product present in the container;
Fig. 9 gives a sectional view of the discharge cap shown in Fig. 8 with above it the foil of the container according to the invention; and
Fig. 10 shows the discharge cap and foil shown in Fig. 9 during use.

Detailed description of the drawings

Fig. 1 shows a first embodiment of the container 1 according to the invention together with a sectional view of a container basket 11. The container 1 contains coffee grounds 2 and has the shape of a truncated cone that has a side wall having a flange 4 and two end walls 5 and 6. The side wall with flange and the bottom end wall are formed from a sheet of filtering material. The sheet of filtering material may be both woven and non-woven fabric. Non-woven or fleece is a category of textile fabrics that are neither woven nor knitted. Contrary to the conventional manufacture of a textile cloth, no yarn is used, but the fabric is directly used as a fibre or filament in a fleece and then bonded together.
The top end wall is built up of three layers, the bottom layer 9 of which is also a sheet of filtering material. This sheet of filtering material is covered by a thin sheet of elastic plastic material, preferably polyethylene. This polyethylene sheet is covered by a thicker sheet of hard, less elastic plastic material, preferably polylactide. The layer of polylactide is provided with a relatively large number of holes. These holes are formed, for example, by means of a CO₂ laser.
Before this container can be used in a machine suitable for working together with cups, the container is first to be inserted into a container basket 11. This container basket is provided with a rigid side wall 13 also having a flange 14 so as to avoid that liquid easily flows via the porous side wall along the outside of the container to draining holes in the machine. In the embodiment shown the side wall 13 is tapered. However, the side wall may also have a cylindrical or substantially cylindrical shape.
Fig. 2 gives a sectional view of a second embodiment of the container according to the invention. This container 21 has a tapered or substantially cylindrical side wall 23 and an end wall 25 which forms a bottom (possibly provided with holes) which are both made of a rigid material and form a cup open at an end side. The side wall rim bordering on the open end side is provided with a flange 24 projecting outwards in radial direction. A foil 26 comprising two layers 27 and 28 is sealed to this flange so that this foil closes the open end side. The outermost layer 27 of this foil is formed by a sheet of hard plastic material, preferably polylactide, and the innermost layer 28 of this foil is formed by a sheet of elastic plastic material, preferably polyethylene or another biologically degradable/compostable layer. Here too the sheet of polylactide (PLA) is provided with a relatively large number of holes.
The coffee grounds 2 are present in the container 21 in a compressed state in order to avoid that the water/extract forms channels through the coffee grounds and coffee seeks its way out through these channels and not through the entire amount of coffee grounds. Here too it holds that the side wall 23 may also have a cylindrical or substantially cylinderical shape in lieu of the shown tapered shape.
For illustrative purposes Fig. 3 shows a sectional view of a part of the upper side wall 6 of the container shown in Fig. 1. The sheet of filtering material 9 is sealed to the flange 4 of the side wall 3.To the sheet of filtering material 9 is attached the thin polyethylene sheet 8 and to this sheet is attached the polylactide sheet 7 carrying the holes. Fig. 4 shows the wall portion shown in Fig. 3 during use in a machine. As a result of the pressure build up on the inside of the foil the elastic polyethylene layer 8 will be deformed at the location of the holes 10 in the polylactide layer 7. If the pressure build up continues at least at the location of a number of holes 10, the thin layer 8 will stretch out and on the other side of the first layer form bulges 8b and then tear open, so that through-holes will be formed in the end wall 6 through which the coffee is allowed to flow out. During the pressure build up there will be a moment when all or substantially all bulges will simultaneously break or tear open.
Fig. 5 gives a sectional view of a second embodiment of the wall portion 6' constituted by two layers that have a different modulus of elasticity during use in a machine. The first layer 7' is then formed by woven yarns to which the second layer 8' is attached. To the second layer on the other side of the first layer is attached a layer 9' of filtering material. The holes 10' are then formed among the yarns. When the pressure is built up in the container, at the location of the draining holes 35 in the discharge cap 33 of the machine the elastic second layer 8' will be stretched as a result of the holes in the first layer 7' and form bulges 8b' on the other side of the first layer. When the pressure is built up even more, these bulges will tear open so that through-holes are formed through which the coffee can be allowed to flow out. The torn bulges 8b' form spouts/funnels with small orifices. By way of illustration Fig. 6 gives a top view of the wall portion 6' shown in Fig. 5, where the layer of filtering material has been omitted.
Fig. 7 shows the container 1 shown in Fig. 1 during use in a machine 31 suitable for this purpose. During the preparation of coffee a liquid is pressure injected into the cup indicated by means of arrow A. As a result of the liquid under pressure in the container basket 11 the end wall 6 is partly pressed through the waffle structure of the discharge cap 33 (indicated by broken lines) so that it tears open at a number of places. A number of the partly torn parts of the end face close a number of draining holes 35 in the wall, so that in the end a confined draining hole is left. As a result the pressure built up in the container basket 11 is maintained during the extraction process and foam is formed.
For illustrative purposes Fig. 8 shows in a top view a waffle-iron-shaped discharge cap 33 of a known machine for extracting the product present in the container. The discharge cap 33 is provided with protuberances 37 while the draining holes 35 are situated among the protuberances. The height of the protuberances 37 is 1.2 mm and the distance between the draining holes 35 is 4 mm.
Fig. 9 gives a sectional view of the discharge cap 33 with above it a two-layer foil 61 of which one layer is provided with holes. The lines 63 are the axes of the holes present in the foil. During use of the container in the machine the foil 61 will cling around the protuberances 37, cf. Fig. 10. The distance between the holes is 2 mm in this embodiment. At the location of the side walls 39 of the protuberances 37 the foil 61 is stretched out the most. As a result of the selected distances between the openings, a hole-carrying part of the foil will always be present at the location of these side walls or at any rate most of the side walls. Since the foil is stretched out the most at this spot, the second layer will tear open the first here at the holes, which is advantageous for obtaining a good/optimal extraction process.
Although the invention has been described in the foregoing based on the drawings, it should be observed that the invention is not by any manner or means restricted to the embodiments shown in the drawings. The invention also extends to all embodiments deviating from the embodiments shown in the drawings within the scope defined by the claims. For example, the hole-carrying hard layer in the embodiment shown in Fig. 1 may also be present between the sheet of filtering material and the more elastic layer. In the embodiment shown in Fig. 2 the hole-carrying hard layer may also be present on the inside of the container and the thin, more elastic layer may be present on the outside.
Furthermore, the second layer may be provided with a moisture and oxygen barrier to retain the quality of the contents of the container. It is also possible to have an extra moisture and/or oxygen barrier layer present between the first and the second layer. Further, fluorine may be applied by vaporization to the first and/or second layer by means of fluorination.

Claims

A container (1; 21) containing a product (2) to be extracted, more particularly coffee grounds or cut tea leaves, the container being provided with a plurality of walls (3,5,6; 23,25,26), of which at least one wall portion (6; 26) comprises at least two layers of which a first layer (7; 27) carries a multitude of holes (10), characterized in that the first layer (7; 27) is made of a fabric that has a modulus of elasticity of more than 1500 N/mm² and the second layer (8; 28) is impermeable to liquid and made of a fabric that has a modulus of elasticity of less than 1000 N/mm².
A container as claimed in claim 1, characterized in that the first layer (7; 27) is made of a fabric that has a modulus of elasticity that exceeds 2000 N/mm².
A container as claimed in claim 2, characterized in that the first layer (7; 27) is made of a fabric that has a modulus of elasticity that exceeds 3000 N/N/mm².
A container as claimed in claim 2 or 3, characterized in that the first layer (7; 27) is made of polylactide.
A container as claimed in claim 1, characterized in that the first layer (7; 27) is located on the outside of the container (1; 21).
A container as claimed in any one of the preceding claims, characterized in that the first layer is made of woven yarns while the holes are formed among the yarns.
A container as claimed in any one of the preceding claims, characterized in that the second layer (8; 28) is made of a fabric that can stretch out to at least one and a half times its length at room temperature before it tears open.
A container as claimed in claim 2, characterized in that the second layer is made of a fabric that can stretch out to at least twice its length at room temperature before it tears open.
A container as claimed in claim 7 or 8, characterized in that the second layer (8; 28) is made of polyethylene.
A container as claimed in any one of the preceding claims, characterized in that the second layer (8; 28) weakens at a lower temperature than the first layer (7; 27).
A container as claimed in any one of the preceding claims, characterized in that the second layer (8; 28) is thinner than the first layer (7; 27).
A container as claimed in any one of the preceding claims, characterized in that the second layer is provided with a moisture and oxygen barrier or that an additional moisture and/or oxygen barrier layer is present between the first and second layer.
A container as claimed in any one of the preceding claims, characterized in that fluorine is applied by vaporization to the first and/or second layer by means of fluorination.
A container as claimed in any one of the preceding claims, characterized in that the container (1) is formed like a cylinder or a truncated cone having a round side wall (3) and two end walls (5,6), where at least one of the end walls (6) comprises said wall portion and the further container walls (3, 5) each also comprise a layer of filtering material and where the container forms a container basket for a cup (11) open at an end side and having a round side wall (13).
A container as claimed in any one of the preceding claims 1 to 17, characterized in that the container (21) is formed like a truncated cone having a round side wall (23) and two end walls (25, 26), where at least one of the end walls (26) comprises said wall portion and the further walls (23, 25) are made of rigid water impermeable fabric and form a cup open on one side, where the side wall rim bordering on the open end side is provided with a radially outward projecting flange (24) where the side wall (23) and end wall (25) of the cup are made of oxygen impermeable fabric.