METHOD AND PACKAGING MACHINE FOR MANUFACTURING A COMPOSTABLE POD FOR BREWING PRODUCTS

A method for manufacturing a compostable pod for brewing products involves arranging a first (2) and a second sheet (3) made of biodegradable material with gas barrier properties; shaping the sheets (2, 3) so as to make at least one first concave portion (2a) on the first sheet (2) and at least one second concave portion (3a) on the second sheet (3) delimited by respective peripheral annular portions (2a′, 3a′), folding the sheets (2, 3) at the peripheral annular portions (2a′, 3a′) so as to define respective stiffening annular portions (2b, 3b) of the sheets (2, 3), filling the first concave portion (2a) with a predetermined quantity (4) of a brewing product, and coupling the sheets (2, 3) at the peripheral annular portions (2a, 3a) so that the respective concavities of the concave portions (2a, 3a) are opposite each other and define a housing volume of said brewing product.

This invention relates to a method and a packaging machine for manufacturing a compostable pod for brewing products.

This invention finds its main application in the food sector, more particularly in the technical field of manufacturing pods for brewing products, such as coffee or tea, or the like.

In the last few years, in the field of brewing products, packaging solutions for products such as capsules and pods have become increasingly popular. These solutions ensure the brewing products are easy to use in special machines that speed up the preparation of the drink.

Although, of the two main solutions, the pod was considered preferable due to its only having biodegradable material (e.g., filter paper) in contact with the product, over time the technique increasingly focused on improving the quality of capsules, both for reasons of economy and in the light of capsules' better maintenance of the organoleptic qualities of the product.

In fact, capsules make it possible to avoid the need for additional packaging with respect to the capsule itself and, by their very nature, guarantee a gas barrier that maintains the quality of the product contained therein, even for long periods.

For this reason, some manufacturers have recently opted to modify the concept of the “pod”, developing models that, while maintaining the canonical disc conformation, were made with materials capable of providing a gas barrier, such as aluminium, or the like.

Unfortunately, this solution is not in line with the significant increase in recent years in both institutions' and consumers' awareness regarding environmental issues.

The use of materials other than aluminium, today, encounters, moreover, considerable problems of both stability and size, thus discouraging technicians in the sector from experimenting with the use of biodegradable/compostable materials.

During the shaping step for shaping the concave portions defining the two halves of the pod, it is, in fact, possible that the sheets of compostable material undergo sagging, displacements, and misalignments due to the poor stiffness of the material, which can result in the pod's ineffective closure during the coupling of the sheets.

In addition, the Applicant has pointed out that the use of biodegradable material may lead to shrinkage in the material itself, which may result in tears or cracks in the finished pod.

The purpose of this invention is, thus, to overcome the drawbacks of the prior art mentioned above.

In particular, the purpose of this invention is to provide a method and a packaging machine for manufacturing a pod for brewing products that enables the use of compostable materials, increasing the efficiency of the production process and improving the quality of the pod that is made.

Said purpose is achieved with a method for manufacturing a compostable pod for brewing products with the characteristics of one or more of claims1to5, and with a packaging machine for manufacturing a compostable pod for brewing products with the characteristics contained in claim12.

In particular, the method involves arranging a first and second sheet made of biodegradable material with gas barrier properties.

The method preferably involves forming the sheets so that at least one first concave portion is made on the first sheet and at least one second concave portion is made on the second sheet, wherein the concave portions are bounded by respective peripheral annular portions.

According to a first aspect of this invention, the method comprises the step of folding the sheets at the peripheral annular portions so as to define respective stiffening annular portions in the sheets.

The method preferably involves the step of filling the first concave portion with a predetermined quantity of a brewing product.

The method preferably involves the step of coupling the sheets at the peripheral annular portions so that the respective concavities of the concave portions are opposite each other and define a housing volume of said brewing product.

The stiffening annular portions, therefore, advantageously enable the concave portions to be stiffened externally so that the subsequent coupling steps are carried out correctly and precisely.

In this way, the efficiency of the packaging process is improved, as no machine stoppages or special devices for supporting, checking, and aligning the sheets are required, and the resulting pod is qualitatively improved.

The shaping step and the folding step are preferably carried out simultaneously in order to optimise the packaging process.

The method preferably comprises a cutting step for cutting the peripheral annular portions following the coupling step, along respective cutting lines between the concave portions and the stiffening annular portions.

Advantageously, the presence of stiffening annular portions increases the stiffness of the sheets and keeps them in the correct position during the cutting step.

The shaping steps for the first and second sheets preferably involve moistening at least a first portion of said first sheet and a second portion of said second sheet.

In addition, it preferably involves configuring said first and said second portion so as to make said first and said second concave portion.

There is, preferably, a drying step for drying the first and second concave portion.

Advantageously, thanks to the moistening step, it is possible to make the cellulose components of the biodegradable material with gas barrier properties more malleable, making it possible to conform the moistened portions by punching or other methods known in and of themselves.

In addition, the subsequent drying step enables the moistened and conformed material to crystallize, thus maintaining the correct profile to proceed with the filling and final closure of the pod.

This methodology therefore makes it possible to manufacture a compostable pod with gas barrier properties in a simple and cost-effective way that is advantageous for the manufacturer.

This invention also relates to a shaping station and a packaging machine for manufacturing a compostable pod for brewing products, comprising said shaping station.

The shaping station comprises a feeding unit of at least one sheet made of biodegradable material with gas barrier properties and a conformation device.

The conformation device shall preferably comprise a shaping device and a folding device.

The shaping device comprising at least one movable punch moving closer to and away from a die provided with a concavity delimited around the edge by a peripheral edge.

The shaping device is configured to form at least one concave portion and one corresponding peripheral annular portion on the respective sheet.

The folding element is configured to be placed outside the peripheral edge of the die to make a fold in the sheet at the peripheral annular portion so as to define at least one stiffening annular portion on the sheet.

Advantageously, therefore, the presence of the folding element makes it possible to stiffen the sheets at the peripheral annular portions adjacent to the concave portions that will be used to make the pod once coupled.

The folding element is preferably mobile, moving closer to and away from an abutment portion that is placed outside the peripheral edge of the die and configured to receive the folding element against it in order to make the fold.

The abutment portion, with reference to a reciprocal movement direction between the punch and the die, is preferably interposed between the peripheral edge of the die and a bottom portion of the concavity.

Advantageously, this configuration enables the creation of the stiffening annular portion on the sheet

The distance, measured along the reciprocal movement direction between the punch and the die, between the peripheral edge and the abutment portion preferably ranges between 0.5 mm and 2 mm, and is, even more preferably, 1.3 mm.

The distance, measured along the reciprocal movement direction between the punch and the die, between the peripheral edge and the bottom portion, preferably ranges between 3 mm and 7 mm, and is, even more preferably, 5 mm.

There is also, preferably, at least one moistening device of at least one portion of said first or second sheet.

In addition, heating elements are preferably provided, configured to dry said portion enabling the maintenance of said concave conformation.

Advantageously, the packaging machine is provided with a first shaping station configured to provide a first sheet made of biodegradable material with gas barrier properties provided with at least one first concave portion and a second shaping station configured to provide a second sheet made of biodegradable material with gas barrier properties provided with at least one second concave portion.

In addition, there is a filling station operationally arranged downstream of said first shaping station and configured to fill said first concave portion with a predetermined quantity of a brewing product.

Finally, a coupling station is operationally arranged downstream of said filling station and is configured to couple the sheets at the peripheral annular portions so that the respective concavities are opposite each other and define a housing volume of said brewing product.

In accordance with a second aspect of this invention, which is alternative or complementary to the preceding one, there is a method and a machine for making a compostable pod for brewing products characterised in that the depth of the concavity of the die of the shaping device is oversized in relation to half the height of the packaged pod.

In other words, by coupling deeper concave portions, for the same quantity of brewing product inserted, even if shrinkage in the compostable material with gas barrier properties should occur (which may result in compacting of the pod and therefore thinning of the pod thickness) the shrinkage would be compensated for.

With reference to the appended figures, the reference number1denotes a packaging machine used to implement the method for manufacturing a compostable pod for brewing products according to this invention.

The machine1, as well as the manufacturing method implemented by it, therefore finds application in the production and manufacture of disposable compostable pods, of the type used in preparing beverages, mostly hot, by brewing or percolation.

Generally speaking, the pod100is an element comprising a first concave portion2aand a second concave portion3acoupled to each other so that their respective concavities are opposite each other and define a housing volume within which a predetermined quantity of a brewing product is placed.

It should be noted that the pods100manufactured with the machine and method according to this invention may be of various types and the brewing products contained therein may be the most varied, such as (preferably) coffee, tea, herbal tea, or the like.

Procedurally, a first2and a second sheet3are first prepared from biodegradable material with gas barrier properties.

The term “sheet” is intended to define any flexible element with a planar extension having two flat faces opposite each other.

It should be noted that the definition of “sheet” is intended to include both elements with a well-defined planar extension and reels of material in which the length of the material is much greater than its width.

In fact, the spirit of the invention is intended to include both “in-line” solutions and more stationary solutions, in which single sheets of material are processed in a separate manner.

The first2or second sheet3made of biodegradable material with gas barrier properties is a preferably made of a composite having a cellulosic component and a biopolymeric or bioplastic component.

This material is devoid of any fossil or petroleum derivative content, allowing it to be considered fully compostable or biodegradable under any national regulations, even the most stringent.

In a preferred embodiment, the biodegradable material with gas barrier properties has a weight ranging between 90 and 150 grams.

The biodegradable material with gas barrier properties preferably comprises multiple overlapping layers, including one or more of the following:a non-woven fabric that is at least 40% by weight, preferably 100%, made of biodegradable fibres;a layer of adhesive suitable for contact with food, in any case less than 5% by weight of the material;a barrier medium that reduces gas permeability, such as vegetable parchment or the like.

The biodegradable fibres used may for example be selected from a group containing:PLA (polylactic acid),PHA (polyhydroxyalkanoates);PHB (polyhydroxybutyrate);PHB(V) (polyhydroxybutyrate-co-hydroxyvalerate);PBS (polybutylene succinate);biopolyester;cellulose fibres such as cotton, flax, and wood fibres.

The adhesive layer, if present, is preferably of the acrylic type.

In order to manufacture the pod100, it is generally necessary to include a step for shaping the first2and second sheet3so that the first concave portion2ais made on the first sheet2and the second concave portion3ais made on the second sheet3.

An array of first concave portions2aand a corresponding array of second concave portions3aare, preferably, made on the first2and second sheet3.

In particular, the shaping of the sheets2,3creates concave portions2a,3abounded by corresponding peripheral annular portions2a′,3a′.

It should be noted that, such shaping steps may be performed at the same time or in successive steps, at the same station or at different stations, in each case adhering to the spirit of this invention.

Advantageously, the method then comprises a folding step for folding the sheets2,3at the peripheral annular portions2a′,3a′ so as to define respective stiffening annular portions2b,3bof the sheets2,3, as illustrated inFIG.4.

In accordance with a possible embodiment of this invention, the shaping steps of the first2and second sheet3preferably involve moistening at least one first portion of said first sheet2and a second portion of said second sheet3.

Moistening or soaking the sheet portions2,3is preferably performed by hitting the first and said second portions with at least one steam jet at a predetermined temperature.

Alternatively, however, the moistening step could be performed using other methods. For example, the moistening step could be performed by nebulisation of a liquid (e.g., demineralised water) on the sheet2,3or by soaking the sheet2,3by means of suitable devices (baths, rollers, sponges).

In accordance with a preferred embodiment, the step of moistening the first or second portion is performed by hitting the two faces of each first2or second sheet3with two separate, preferably independently driven and adjustable, steam jets.

Advantageously, this enables differentiated soaking of the different layers of the biodegradable material with gas barrier properties.

The shaping step also involves conforming the first and second portion so as to make the first2aand second concave portion3a.

In other words, it involves conforming, for example by means of a punch, mould, or the like, the previously moistened portion of the first2and the second sheet3.

In this way, the cellulose fractions of the material are, advantageously, more malleable and the risk of breakage is considerably reduced, while maintaining production speeds compatible with the cycle times required by today's market.

Following the conformation, or concurrently therewith, the first2aand second3aconcave portions are then dried.

In other words, the drying step involves heating the first2aand the second3aconcave portions, concurrently with or subsequent to said conformation, so as to crystallize the shape of the resulting material.

The concave portions2a,3aresulting from the shaping step are then used to manufacture the pod100.

In particular, the first concave portion2ais filled with a predetermined quantity4of a brewing product, which, as already mentioned, can be of various kinds.

The method then involves coupling the sheets2,3at the peripheral annular portions2a′,3a′ so that the respective concavities of the concave portions2a,3aare opposite each other and define a housing volume of the brewing product.

In other words, the first concave portion2afilled with said quantity4is coupled with the second concave portion3aso that the respective concavities are opposite and define a housing volume for said brewing product.

Advantageously, therefore, the method to which this invention relates makes it possible to manufacture a pod100, wherein both the first2aand the second concave portion3aare pre-shaped and made of a biodegradable material with gas barrier properties of a high quality. In fact, coupling the peripheral annular portions2a′,3a′ is precise and effective since the sheets2,3have been stiffened by the stiffening annular portions2b,3bduring the folding step.

The shaping step and said folding step are preferably carried out simultaneously, as will be clearer in the following description.

Finally, the method preferably comprises a cutting step for cutting the peripheral annular portions2a′,3a′, following the coupling step, along respective cutting lines T (as illustrated inFIG.4) between the concave portions2a,3aand the stiffening annular portions2b,3b.

Thus, the stiffening annular portions2b,3bconstitute waste at the end of the process, but play an important supporting and stiffening function during the coupling steps.

In order to implement this method, for example, the packaging machine1to which this invention relates is used.

This machine1comprises one or more shaping stations5,6, a filling station7, and a coupling station8.

In particular, the machine1comprises a first shaping station5and a second shaping station6.

The first shaping station5is configured to provide the first sheet2of biodegradable material provided with said first concave portion2a,preferably with an array of first concave portions2a.

The second shaping station6is configured to provide the second sheet3made of biodegradable material provided with said second concave portion3a,preferably with an array of second concave portions3a.

It should be noted that the first5and the second shaping station6could be located within the same device and act simultaneously on the two sheets2,3or be physically separated from each other, adhering, in any case, to the spirit of this invention.

Each shaping station5,6comprises a feeding unit9of the corresponding first2or second sheet3of biodegradable material with gas barrier properties.

This feeding unit9is configured to feed the sheet2,3(or ribbon) along a forward direction “A”.

Along said forward direction “A”, there is preferably a moistening device10of at least one portion of the respective first2or second3sheet.

The moistening device10preferably comprises at least one steam generator10aconfigured to generate a steam jet “V” hitting the comprises portion of the first2or second3sheet.

In the preferred embodiment, the moistening device10comprises two steam generators10aopposite each other, each oriented towards a corresponding face of the first2or second3sheet.

These steam generators10aare preferably independently driven, in order to differentiate and optimise the soaking of each face of the sheet2,3.

Alternatively, however, other moistening systems could be used, such as nebulising nozzles/sprays or application rollers (e.g., with brushes or sponges).

The shaping station5,6comprises a conformation device11, preferably operationally arranged downstream of the moistening device10.

The conformation device11comprises at least one shaping device12.

The shaping device12is configured to give the, preferably soaked, portion of the sheet a concave conformation.

With reference toFIG.2, the shaping device12comprises at least one punch12a,preferably convex, that can be moved closer to and away from a die12b—which is preferably concave, provided with a concavity12b′, and delimited around the edge by a peripheral edge12b″—in a reciprocal movement direction (preferably perpendicular to the forward direction A).

Thus, the shaping device12is configured to form at least one concave portion2a,3aand one corresponding peripheral annular portion2a′,3a′ on the respective sheet2,3.

Advantageously, the conformation device11comprises a folding element14configured to be placed outside the peripheral edge12b″ of the matrix12bto make a fold P in the sheet2,3at the peripheral annular portion2a′,3a′ so as to define at least one stiffening annular portion2b,3bof the sheet2,3.

In other words, the folding element14pushes the sheet2,3and folds it along the peripheral edge12b″ creating the fold P that results in a stiffening of the area itself. In fact, the presence of a stiffening annular portion2b,3b, which is not coplanar, and preferably lying substantially on a transverse plane in relation to the peripheral annular portion2a′,3a′, increases the stiffness of the sheet2,3.

In other words, as a result of the intervention of the folding element the peripheral annular portions2a′,3a′ are arranged to straddle the respective peripheral edge12b″, with the fold P and the annular edge of the concave portion2a,3agrasping the corresponding edges (or fittings) of the peripheral edge12b″. In this way, the correct positioning of the concave portion within the concavity is ensured, improving product quality and reducing waste.

The folding element14is preferably mounted on the shaping device12and can preferably be moved in conjunction with this device.

The folding element14can preferably be moved closer to and away from an abutment portion12cthat is placed outside the peripheral edge12b″ of the die12band configured to receive said folding element14against it in order to make the fold P.

With particular reference toFIG.3, the abutment portion12c,with reference to the reciprocal movement direction between the punch12aand the die12b,is preferably interposed between the peripheral edge12b″ of the die12band a bottom portion12fof the concavity12b′.

The distance D1, measured along the reciprocal movement direction, between the peripheral edge12b″ and the abutment portion, preferably ranges between 0.5 mm and 2 mm, and is, even more preferably, 1.3 mm.

The distance D2, measured along the reciprocal movement direction, between the peripheral edge12b″ and the bottom portion12f,ranges between 3 mm and 7 mm, and is, even more preferably, 5 mm.

In this regard, according to an additional aspect of this invention, in order to solve the problem of shrinkage in the biodegradable material with gas barrier properties with which the sheet2,3is made, it is possible to determine the distance D2so that it is half the thickness S of the packaged pod100increased by an additional value X able to compensate for this material shrinkage, whereby D2=S/2+X.

The additional value X may preferably take a value ranging between 10% and 30% of the thickness S.

Therefore, by increasing the depth of the concavity12b′ of the die12b,for the same amount of brewing material inserted into the first concave portion2a,it is possible to prevent shrinkage in the biodegradable material with gas barrier properties from resulting in the breaking of the pod100.

The conformation device then, preferably, comprises heating means13configured to dry the conformed sheet portion2,3, allowing subsequent maintenance of said concave conformation.

In addition, the heating means13preferably comprise a heating device13ajoined to said punch12aand/or to said die12bin order to dry the concave portion2a,3aof the first2or second3sheet during its conformation.

The heating device13ais preferably defined by at least one resistor integrated into the punch12aor die12b.

In the preferred embodiment, the shaping device12is configured to exert a compressive force ranging from 1000 to 3000 N.

On the other hand, the heating device13ais preferably configured to raise the temperature of the punch12aor die12bto a temperature ranging between 50 and 130° C. during the conformation step. Advantageously, a precise conformation of the concave portions2a,3acan thus be obtained quickly and reliably.

The filling station7preferably comprises a dosing device7a,itself known and therefore not described in detail. The dosing device7amay be of the weight, time, or volume type, in each case adhering to the spirit of this invention.

The coupling station8, in turn, may be of various types. It preferably involves using an ultrasonic welding device8a(sonotrode) in order to avoid or limit the presence of adhesive.

Alternatively, however, a heat sealer or other known system may be used.

The drying step carried out during the conformation also allows a precise maintenance of the conformation, facilitating the subsequent filling and coupling steps and freeing the producer from the need to use suction or vacuum systems to maintain it.

This invention achieves the proposed purposes, overcoming the drawbacks complained of in the prior art and providing the user with a method and a machine for manufacturing a compostable pod made of biodegradable material with gas barrier properties for high-quality brewing products.

In particular, the invention makes it possible to effectively implement the coupling step for coupling the two concave portions that make the capsule.