LU502616B1 - Capsule intended to receive a substance for the preparation of a drink - Google Patents

Abstract

The invention relates to a capsule (1) intended to receive a substance for the preparation of a drink, said capsule comprising a body having a side wall (2) bordered on either side by a bottom (3) and by a rim (4) surrounding an opening (5) of said body, the body being formed by molding a cellulose pulp, the side wall (2) of said body being covered with a sealing label (18).

Description

Capsule intended to receive a substance for the preparation of a drink

The invention relates to a capsule intended to receive a substance for the preparation of a drink.

Capsules are known whose body has a side wall bordered on either side by a bottom and by a rim surrounding an opening of said body, the substance for the preparation of a drink being introduced into said capsule through said opening, then enclosed inside said capsule by association, for example by gluing, of a cover on the rim to obscure the opening.

Such capsules are intended in particular for the preparation of a hot drink such as coffee, tea or infusion. To do this, a capsule is installed in the housing of a machine intended for this purpose, where it is held by a piston while an extracting liquid, for example hot water, passes through it and the substance that it contains.

The capsule must be opened to allow the flow of the drink through it, but the substance must be kept in the capsule with good barrier properties against oxygen and humidity in the air in order to preserve its organoleptic properties.

To do this, capsules are known whose body is formed by stamping a sheet of metallic material, in particular aluminum. Such capsules have good air and humidity sealing properties, but are expensive to produce, in addition to being difficult to recycle.

We also know, for example, documents WO-2019/185637 and

WO-2022/112615, capsules whose body is formed by injection molding of a compostable plastic material, these capsules further comprising a sealing film which is associated with at least one of the bottom, the side wall or the upper opening of said body, in particular during its molding following an IML (for English “In-Mould Labeling”) process, said film being compostable and having barrier properties to oxygen and/or to humidity.

These capsules have an improved ecological impact, in that they are notably biodegradable and compostable, both industrially and domestically, and also guarantee good organoleptic preservation of the substance they contain.

However, in practice these capsules prove to be expensive and complex to produce.

The invention aims to improve the prior art by proposing a capsule combining good barrier properties to oxygen and humidity while having a limited ecological impact, in particular by being biodegradable and/or compostable, while being easy and inexpensive to produce.

For this purpose, the invention proposes a capsule intended to receive a substance for the preparation of a drink, said capsule comprising a body having a side wall bordered on either side by a bottom and by a rim surrounding an opening of said body, the body being formed by molding a cellulose pulp, the side wall of said body being covered with a sealing label.

Other features and advantages of the invention will appear in the description which follows, made with reference to the appended figures, in which: - Figure 1 represents in exploded perspective a capsule according to one embodiment of the invention; - Figures 2 and 3 each represent in exploded perspective, respectively bottom view (Figure 2) and top view (Figure 3), a capsule according to another embodiment of the invention respectively.

° LU502616

In relation to these figures, a capsule 1 intended to receive a substance for the preparation of a drink is described below.

The capsule 1 comprises a body having a side wall 2 bordered on either side by a bottom 3 and by a rim 4 surrounding an opening 5 of said body.

The body is formed by molding a cellulose pulp, and preferably contains exclusively cellulose, in particular from 100% sustainable and/or organic farming.

Thus, it is possible to manufacture an easily recyclable capsule 1 inexpensively and with high yield, with reduced carbon dioxide emissions, in particular compared to injection molding of a plastic material.

In addition, the exclusive use of cellulose makes it possible to obtain a capsule 1 whose body can be easily composted, both industrially and domestically, in particular with a reduced composting duration (of the order of one month) compared to the average composting time of capsules made from compostable molded plastic material (around 6 months).

In particular, capsule 1 is biodegradable and/or compostable according to the standard

EN 13432.

The body is formed by dry molding of a sheet of cellulose pulp, which makes it possible to considerably increase the manufacturing yield of the capsule while limiting the number, size and cost of the necessary installations, as well as water and energy costs.

In particular, the use of such a manufacturing process makes it possible to obtain a production yield of capsules 1 of the order of 1000 capsules per minute, for an annual production volume greater than a billion capsules 1.

*LU502616

The method of manufacturing the body of the capsule 1 may in particular provide for: - separating cellulose fibers from a source of cellulose, in particular by grinding a natural source of cellulose, such as wood pulp, cotton, flax, hemp, or even sugar cane, or a recycled source, such as paper, cardboard or textile; - collect the cellulose fibers thus separated on a treadmill, in particular by injecting them with air before their grinding, following a process called "laid air", so as to form on said treadmill a fluffy, thick and dense, with a weight of between 300 and 15,000 g/m? ; - compact said fluffy layer, in particular by passing between two compressor rollers, possibly heated, so as to obtain a sheet of cellulose pulp of controlled thickness, in particular between 500 and 700 µm; - preheat said sheet, in particular at a temperature between 150 and 170°C; - compress said sheet thus preheated in a mold of suitable shape, in particular by means of a hydraulic press, with a pressure of the order of 45 MPa, in order to obtain capsule bodies 1 from said compressed sheet.

The cellulose pulp used makes it possible to obtain the food compatibility which is necessary for packaging a substance for preparing a drink in capsule 1, in particular by avoiding the addition of an interior coating compatible with food.

In particular, the cellulose pulp used is free of substances harmful to health and/or the environment, which could contaminate the substance used to prepare the drink by contact with the body of the capsule 1.

Advantageously, the cellulose pulp forming the body of the capsule 1 comprises microfibrillated cellulose (MFC, for English Micro-Fibrillated

Cellulose), in particular between 1% and 50% by weight of MFC microfibrillated cellulose.

MFC microfibrillated cellulose is made up of individual cellulose microfibrils or in the form of aggregates. These microfibrils generally have a diameter of 2 to 20 nanometers, and a length of around 5 micrometers. Microfibril aggregates are composed of several cellulose microfibrils clumped together.

The production of MFC microfibrillated cellulose is based on the release of the constituent elements of the secondary wall of lignocellulosic fibers by mechanical means coupled with enzymatic or chemical pretreatments.

The fibers used can be unbleached or bleached chemical pulps, mechanical pulps produced from wood, recycled pulps, etc.

In relation to Figures 1 to 3, the body of the capsule 1 has a geometry of revolution around a central axis forming a side wall 2 which is generally inscribed in a truncated cone with a straight generatrix between the bottom 3 and the upper edge 4.

The capsule 1 is equipped with an upper cover 16 which is associated with the rim 4 to cover the opening 5, forming in said body a compartment for loading the substance.

In the embodiments shown, the opening 5 can allow the substance to be loaded into the compartment which is closed on the opposite side by the bottom 3, said opening then being closed by the upper cover 16 after said loading.

In Figure 1, the bottom 3 comprises a lower opening 6 intended to be covered by a lower cover 17. In particular, the lower opening 6 can be obscured first by the cover 17, in order to load the substance into the compartment through the upper opening 5, which is then closed by the cover 16.

° LU502616

Alternatively, the capsule 1 shown in Figure 1 can be loaded through the bottom 3. In this case, the upper opening 5 is obscured first by the cover 16, then the capsule 1 is turned over to be able to load the substance through lower opening 6, the lower cover 17 then being associated with said capsule to close said compartment before preparing the drink.

Capsule 1 is intended in particular for the preparation of a hot drink such as coffee, tea or infusion. To do this, the capsule 1 can be placed in the housing of a machine provided for this purpose, in order to be crossed by at least one pin to inject extractor liquid, in particular hot water, into the substance contained in capsule 1.

The injection of the liquid induces an increase in the pressure in the compartment to allow, after rupture of a frangible wall of the capsule 1, the flow of the drink out of said capsule.

During the preparation of the drink, the capsule 1 is subjected to an injection of water at a temperature between 86°C and 90°C and under a pressure which can go up to 20 bars, for a duration of approximately 2 minutes . In particular, to prepare a coffee-type drink, the quantity of water injected into capsule 1 is between 40 ML and 150 mL.

The capsule 1 shown in Figures 1 and 3 is adapted to be placed in a machine in which it is held by a piston provided with pins to pierce its bottom 3 or its lower cover 17. In addition, the bottom 3 or the cover lower 17 is crossed by at least one pin to inject extractor liquid into the substance contained in the capsule 1, which induces an increase in pressure in the compartment to allow, after rupture of the upper cover 16, the flow of the drink through opening 5.

In Figure 2, the bottom 3 has a central orifice 19 which opens into the substance conditioning compartment, as well as an upper wall which extends substantially radially in said compartment, and on which is formed a network of pins in relief, a perforable membrane being placed in said compartment between the substance and the raised pins.

Thus, when the capsule 1 is placed in a machine to prepare a drink, the upper cover 16 is crossed by at least one pin to inject extractor liquid into the compartment, which leads to an increase in pressure, under the effect from which the membrane is torn on the raised pins of the bottom 3, in order to allow the drink to flow through the central orifice 19.

To be able to preserve the organoleptic characteristics of the substance stored before its use to prepare a drink, the capsule 1 must be waterproof, in particular by forming a barrier against the circulation of oxygen and humidity, both towards the interior of said capsule, to avoid alteration of the substance it contains by ambient air and humidity, as well as towards the outside, in particular to avoid drying out of a substance packaged in moist and/or greasy form.

In particular, to ensure optimal conservation of the substance, capsule 1 has the following characteristics: - an oxygen transmission rate of less than 10 cm%m° day.atm, in particular at most 5 cm*/m° day.atm, and more particularly less than 1 cm®m?2 day.atm, measured according to standard ASTM D3985; - a water vapor transmission rate of less than 60 g/m2.24h, and more particularly less than 10 g/m2.24h, measured according to the ASTM standard

E96 in tropical conditions (38°C and 90% humidity).

With such characteristics, the capsule 1 can in particular be stored: - before filling with a substance for preparing a drink: at a temperature between 15 and 25°C, and up to 50°C for a maximum duration of 6 weeks during transport;

- after filling: in a dry and temperate place, with a maximum ambient humidity level of between 35 and 55%.

Advantageously, the body of the capsule 1 is subjected to a preliminary treatment to close the pores of the cellulose layer constituting it, in order to form a first barrier against oxygen and water vapor.

Furthermore, the use of a cellulose pulp comprising MFC microfibrillated cellulose contributes favorably to the sealing of the capsule against oxygen and water vapor.

However, to the extent that the material constituting the body of the capsule 1 does not have sufficient performance, in particular due to the porosity of the cellulose, the side wall 2 can be covered with a sealing label 18 and/or a waterproof coating forming a second barrier against oxygen and humidity.

The coating and/or the sealing label 18 can be applied to the side wall 2, not only to reinforce its oxygen and water vapor barrier properties, but also to provide it with additional barrier properties. , in particular lipophobic properties, in order to further preserve the organoleptic properties of the substance packaged in said capsule, but also to prevent the impregnation of the body of the capsule 1 by the substance for preparing the drink, when the latter is presented in form of a moist and/or greasy paste.

In the embodiments shown, the covers 16, 17 ensure tight closure of the capsule 1, in particular by forming a barrier against oxygen and humidity.

Thus, the capsule 1 is equipped with at least one sealing film 12 covering opening 5 and possibly the bottom 3, in order to respectively form the upper cover 16 and the possible lower cover 17.

The upper cover 16 and the possible lower cover 17 are in particular fixed to the body of the capsule 1 by heat sealing, by applying for approximately 350 ms a pressure between 3 and 6 bars at a temperature between 190°C and 260°C.

In the embodiments shown, the side wall 2 is covered with a sealing label 18, which is advantageously formed from the same sealing film 12 as the cover(s) 16, 17.

The sealing label 18 can be associated with the side wall 2 during or after the molding of the body of the capsule 1, following an IML process (for English “In-

Molding Process), during which said label is placed against a side wall of a molding cavity of said body before actually carrying out said molding, so as to simultaneously carry out the steps of forming said body and associating said label to its side wall 2. Alternatively, the label can be associated by thermoforming.

The sealing label 18, and more generally the film 12 constituting said label and the cover(s) 16, 17, may also comprise MFC microfibrillated cellulose.

In particular, the sealing film 12 comprises at least one layer based on MFC microfibrillated cellulose. Advantageously, the MFC layer can be in the form of a layer of paper formed with microfibrillated cellulose so as to be highly fibrillated, in particular being able to be translucent, so as to be able to be a particularly barrier to oxygen.

Furthermore, the use of a cellulose pulp comprising MFC microfibrillated cellulose contributes favorably to the association of the label 18 on the side wall 2, in particular by limiting the granularity of said wall.

For aesthetic and/or commercial reasons, in particular in relation to the production of the label 18, the MFC layer can be provided with a print produced by depositing ink on one of its faces, said print comprising for example information textual and/or a decorative element, such as for example a logo, a brand, and/or a description of the substance contained in capsule 1.

In particular, the MFC layer being transparent, the printing ink can be deposited on its interior face in order to be protected. In addition, to improve the aesthetic qualities of the capsule 1, the printing may have gloss and/or antistatic properties.

According to exemplary embodiments, the MFC layer has: - a thickness of between 30 and 70 μm; and/or - a surface mass of between 40 and 90 g/m°.

The MFC layer makes it possible in particular to obtain a sealing film 12 having a high surface mass and sufficient oxygen tightness for the barrier function, while being perfectly biodegradable and/or compostable.

The sealing label 18 may have been treated to improve its resistance to humidity, for example by means of the sealing coating, applied in the form of a lacquer or by metallization on said label. Alternatively, the sealing coating is applied directly to the side wall 2 of the capsule 1. Furthermore, the sealing coating can also be applied to at least one of the covers 16, 17.

Advantageously, the sealing coating, like the sealing film 12, is biodegradable and/or compostable, in order to improve the total environmental impact of the capsule 1, in particular by avoiding the consumer having to separate the label 18 and the cover(s) 16, 17 of the body of the capsule 1 before its composting.

According to one embodiment, the sealing coating may comprise microfibrillated MFC cellulose, for example from food plants, in particular root vegetables such as beets. Such a composition is notably the subject of document EP-3 145 958.

The waterproofing coating may be based on an aqueous dispersion of MFC microfibrillated cellulose, comprising in particular between 0.5% and 20% by weight of MFC microfibrillated cellulose, in particular less than 5% by weight.

According to one embodiment, the waterproofing coating is made from an anionic dispersion of MFC microfibrillated cellulose, and has in particular the following characteristics: - a solid particle content of around 32% by weight; - a substantially neutral or slightly basic pH, of the order of 7 to 8; - a viscosity of between 300 and 500 mPa.s; - a density of around 1.02 at 20°C.

Such an anionic dispersion has excellent barrier properties to oxygen and humidity, as well as excellent sealing against grease and oil, and can be fixed by heat on its application support, in particular the side wall 2 of the capsule 1 and/or the label 18 covering it, to form a sealing barrier as desired.

In particular, the waterproofing coating can be applied by dipping, by spraying or by transfer, before possibly being exposed to a heat source of a suitable temperature to form a waterproof coating. Advantageously, the surface mass of the waterproofing coating is between 2 and 12 g/m°.

Furthermore, the sealing film 12, in particular the label 18, may comprise a sealing layer on the body of the capsule 1, in particular on its side wall 2, said sealing layer being able to be adapted to hot sealing and/or or cold.

According to one embodiment, the sealing coating forms a metallization layer, for example based on aluminum.

In particular, this layer can be applied by transfer or by spraying with a thickness of less than 10 μm, in particular less than 1 μm.

Claims (11)

1. Capsule (1) intended to receive a substance for the preparation of a drink, said capsule comprising a body having a side wall (2) bordered on either side by a bottom (3) and by a rim (4 ) surrounding an opening (5) of said body, said capsule being characterized in that the body is formed by molding a cellulose pulp, the side wall (2) of said body being covered with a sealing label (18) . 2. Capsule (1) according to claim 1, characterized in that the sealing label (18) comprises a layer based on MFC microfibrillated cellulose. 3. Capsule (1) according to one of claims 1 or 2, characterized in that it has an oxygen transmission rate of less than 10 cm%/m°.day.atm, according to the ASTM D3985 standard. 4. Capsule (1) according to claim 3, characterized in that the oxygen transmission rate is at most 5 cm3®m?2 day.atm, and in particular less than 1 cm*/m?day.atm , according to ASTM D3985. 5. Capsule (1) according to any one of claims 1 to 4, characterized in that it has a water vapor transmission rate which is less than 60 g/m2.24h, measured according to the ASTM standard E96. 6. Capsule (1) according to claim 5, characterized in that the water vapor transmission rate is less than 10 g/m2.24h, measured according to the ASTM E96 standard. 7. Capsule (1) according to claim 6, characterized in that the sealing label (18) has been treated to improve its resistance to humidity. 8. Capsule (1) according to any one of claims 1 to 7, characterized in that the sealing label (18) comprises a sealing layer on the side wall (2). 9. Capsule (1) according to any one of claims 1 to 8, characterized in that at least one, and in particular both, among the body of the capsule (1) and the sealing label (18) is biodegradable and/or compostable. 10. Capsule (1) according to any one of claims 1 to 9, characterized in that the sealing label (18) is associated with the side wall (2) during or after the molding of the body following an IML process . 11. Capsule (1) according to any one of claims 1 to 10, characterized in that the body is formed by dry molding of a sheet of cellulose pulp.