Capsule for Producing a Beverage

The invention relates to a capsule for use in a beverage preparation machine.

Single-serve beverage capsules are known in the art. These capsules are commonly used with beverage preparation machines for on demand dispensing of beverages, like coffee or tea.

For this, usually a beverage capsule with a capsule body that encloses a beverage ingredient is inserted in a capsule receiver of a beverage preparation machine. The capsule receiver is closed and the beverage preparation is started. In the capsule receiver, a top membrane of the capsule is punctured with a needle to inject a fluid, generally water, in the capsule to interact with the beverage ingredient inside the capsule to produce the desired beverage. The fluid fills the capsule so that the pressure inside the capsule increases. When a sufficient amount of fluid fills the capsule, a self-opening mechanism in the capsule is activated and opens a bottom membrane of the capsule to release the prepared beverage at a time when the extraction of the beverage component is completed. Examples of working principles of this type of container are described in patent EP 1472156.

In the prior art, beverage containers of this type are usually made of plastic. Considering that the containers are designed for single time use only, their disposal has to be managed since reusing and recycling the materials used can be challenging. Therefore, attempts are made to replace these materials with alternatives, like cellulose or bioplastic, which allow overcoming the problems existing with disposing and/or recycling the containers after use. However, it has to be considered that these alternative materials do not have the same material characteristics and advantages as the usual plastic materials.

In particular, considering a capsule such as described in patent EP 1472156 and schematically illustrated in, such a type of capsulecomprises:

If the opening deviceof a capsule presenting such a construction is made of a bioplastic, several drawbacks can be observed.

One drawback is that, under rises of temperature and pressure, the properties of objects made of bioplastic can change. In the case of the capsule described above, this change of properties is a serious problem for the opening device made of bioplastic because when hot water is introduced in the chamber and until pressure rises and the bottom membrane is pushed to the opening device, this opening device deforms with the risk of breaking and/or not recovering its original shape after tearing of the bottom membrane and pressure decrease. The result is that beverage ingredient can be dispensed from the ingredient chamber to the drinking cup, such as roast and ground coffee particles or non-dissolved soluble powder, or that a part of the beverage is not correctly prepared. The beverage preparation is not acceptable for the consumer.

Another drawback is that the opening device presents a certain thickness in order to provide a resistance to the pressure that rises in the capsule during the beverage preparation. Consequently, when this thick piece of material ifs made of bioplastic, its disintegration as a home compostable object becomes relatively long.

An object of the invention is to address the above existing problems.

In a first aspect of the invention, there is provided a capsule for use in a beverage preparation machine, said capsule containing a soluble and/or extractable beverage ingredient, and the capsule comprises:

This capsule comprises a capsule body defining a chamber for the beverage ingredient, a top membrane closing this chamber, a bottom membrane provided inside the chamber and an opening device adapted to open said bottom membrane.

The capsule body usually comprises:

Usually the bottom of the capsule body comprises an outlet through which the beverage can be dispensed.

Generally, the top membrane is attached to the upper surface of the flange of the body.

The capsule comprises a beverage ingredient that can be a soluble or extractable beverage ingredient. The ingredient is hold between the top membrane and the bottom membrane.

The opening device is positioned inside the body but outside the ingredient chamber. Accordingly, the opening device is positioned below the bottom membrane.

Usually, the opening device comprises a plate and this plate comprises opening elements rising from the upper surface of the plate, and accordingly in direction of the bottom membrane. These opening elements are designed to pierce, tear, puncture the bottom membrane under the effect of the liquid pressure increase in the ingredient chamber during injection of said liquid.

These rising opening elements can be spikes, cone-or pyramid-shaped (optionally truncated at their ends) turned upwardly towards the bottom membrane which may form protrusions and recesses against the bottom membrane facing the opening device.

Preferably, the opening elements present sharp pointed end.

Preferably, the plate of the opening device comprises beverage evacuation holes extending from the upper surface of the plate to the lower surface of the plate, and said holes being positioned between the rising opening elements.

In the state of the art, this opening device is a moulded piece of plastic such as polypropylene.

In the present embodiment, the opening device is a moulded piece of a biodegradable material. This biodegradable material is a polymeric composition that comprises:

The opening device is manufactured by moulding from this polymeric composition. Usually, the opening device is integrally made of this polymeric composition.

Generally, the polymeric composition comprises at least one polyhydroxyalkanoate containing repeating units of formula (I):

Preferably, the polymeric composition comprises at least one polyhydroxyalkanoate, wherein Ri is methyl or ethyl, and n is 1 or 2.

Preferred repeating units of formula (I) can be those deriving from:

Particularly preferred polyhydroxyalkanoates are:

In one embodiment, the polyhydroxyalkanoate can be a copolymer or terpolymer containing repeating units of formula (I) in combination with at least one repeating unit deriving from comonomers that are able to copolymerize with hydroxyalkanoates.

These comonomers can be lactones and/or lactams.

In this embodiment, usually, the repeating units of formula (I) are present in an amount equal to at least 10% by moles with respect to the total moles of repeating units.

Preferably, the polyhydroxyalkanoate has a weight average molecular weight (M) which can range from 10to 10g/mol.

Generally, the polymeric composition comprises at least one plasticizer selected from the group consisting of:

The polymeric composition comprises at least one nucleant that can be selected from the group consisting of boron nitride, talc, hydroxyapatite, zinc stearate, nanocrystalline cellulose, montmorillonite nano clay, single wall carbon nanotube, wollastonite, multi wall carbon nanotube, cyanuric acid, fatty acids, fatty acid esters, fatty acid amines, fatty acid metal salts, pentaerythritol, di-pentaerythritol, urea derivatives, sorbitol-based compounds, sodium benzoate and mixtures thereof.

Preferably, the polymeric composition comprises a quantity of at least one nucleant of at least 0.1% in weight, preferably at most 5% in weight.

The polymeric composition comprises at least one mineral filler that can be selected from the group consisting of talc, wollastonite, mica, silica, calcium carbonate, kaolin, nano clays.

Preferably, the polymeric composition comprises a quantity of at least one mineral filler of at least 1% in weight, preferably at most 50% in weight.

Preferably, the polymeric composition comprises wollastonite, talc or nanoclays as a mineral filler, even more preferably in a content comprised between 5 and 40% in weight.

It was observed that the presence of mineral fillers inside the polymeric composition of the opening device comprising a polymer selected from the group consisting of polyhydroxyalkanoates (PHA) accelerated the disintegration of this opening compared topolymeric composition devoid of these mineral fillers.

The polymeric composition can comprise at least one functional additive selected from the group consisting of:

These functional additives can be used to improve processability, compatibility between the materials and/or accelerate biodegradation.

The polymeric composition can comprise at least one viscosity modifier and/or compatibilizer selected from the group consisting of:

Preferably, the polymeric composition can comprise fibers such as fibers selected from the group consisting of: flax, corn, rice husk, hemp, bamboo, sisal, kenaf and mixtures thereof. The advantage of integrating fibers in the polymeric composition of the opening device is that the disintegration of the opening part is accelerated compared to the neat PHA-based composition devoid of these fibers. This is particularly useful for the opening device that can be a thick piece of material and consequently that needs more time to be disintegrated thatn the other parts of the capsules.

Preferably, the polymeric composition comprises such fibers in a content comprised between 5 and 40% in weight.

Usually, the opening device comprises a plate, said plate comprising opening elements rising from the upper surface of the plate, said opening elements being designed to pierce, tear, puncture the bottom membrane under the effect of the liquid pressure increase in the ingredient chamber during injection of said liquid.

Preferably the opening elements present sharp pointed ends, in particular when the bottom membrane is made of a material that present a certain elasticity, which can be the case when the bottom membrane is made of a biodegradable material.

It can be the case when the bottom membrane is a laminated multilayer material comprising successively:

With such a bottom bottom membrane, usually the vegetable parchment support faces the opening device inside the capsule.

In one embodiment, it can be preferred that the plate of the opening device comprises beverage evacuation holes extending from the upper surface of the plate to the lower surface of the plate, and said holes being positioned between the rising opening elements. This is particularly preferred when the bottom membrane is a laminated multilayer material such as described above.

Preferably, the capsule body is made of biodegradable or compostable materials, such as paper based, starch, polycaprolactone (PCL), polylactic acid (PLA), polyhydroxyalcanoates (PHA), polybutylene succinate (PBS), polybutylene succinate adipate (PBSA), and/or polybutylene adipate terepthalate (PBAT), polyglycolic acid (PGA) or mixture thereof.