EP4713526A1

EP4713526A1 - A process for molding cellulosic material into a tridimensional package

Info

Publication number: EP4713526A1
Application number: EP24723563.3A
Authority: EP
Inventors: Nicola GALAFFU; Austin GANN; Gerhard Niederreiter
Original assignee: Societe des Produits Nestle SA; Nestle SA
Current assignee: Societe des Produits Nestle SA; Nestle SA
Priority date: 2023-05-15
Filing date: 2024-05-06
Publication date: 2026-03-25
Also published as: CN121175467A; WO2024235687A1; AU2024271293A1

Abstract

The present invention relates to a process for molding cellulosic pulp in one step, into a tridimensional packaging item comprising several layers comprising cellulosic and non-cellulosic material, by passing a mold with cavities through several consecutive baths containing different formulations corresponding to the various layers, to superimpose the various components without the need to separate process steps as in the prior art.

Description

A PROCESS FOR MOLDING CELLULOSIC MATERIAL INTO A TRIDIMENSIONAL

PACKAGE, AND A PACKAGE THUS OBTAINED

Nicola (NMN) GALAFFU

Austin (NMN) GANN

Gerhard (NMN) NIEDERREITER

Field of the invention

Background of the invention

Tridimensional packaging items are manufactured from various materials and techniques. In the most recent years, environmental awareness increased even further, in particular in relation to waste materials, for instance used packages, that are not recycled or treated properly. This challenge is considered very seriously by industrials who spend increasingly extensive efforts to develop new packaging materials that are rapidly and easily recyclable. In order to mitigate the influence of plastic materials used in packaging, new solutions have been developed, which involve recyclable materials such as cellulose pulp - in various forms -.

However, packages have also a protective function, in particular they should include a barrier to moisture and/or oxidation to prevent degradation of the contents, especially when such contents is an edible material that is subject to oxidation or is sensitive to humidity.

In order to provide cellulosic-based packages with barrier properties, current pulp-molded packaging solutions incorporate one or several barrier layers which are thermoformed on an already formed tridimensional pulp preform. The process therefore involves two separate manufacturing steps:

- forming pulp cellulose in a mold into a tridimensional preform, and then

- thermoforming a plastic barrier liner film onto the pulp preform.

Such a process is therefore rather complex and long, and therefore is not very adequate if one considers large industrial productions.

Another drawback that was found by the inventors, is that the adhesion of the barrier (non-cellulosic) layers onto the pulp cellulosic layer is inequal and sometimes even poor which leads to delamination under certain conditions. This is especially the case when the packaging is designed to be traversed by an external element, for instance when said packaging is a capsule for beverage preparation that is pierced by a water-injection element (e.g. a needle or a blade) of a beverage preparation machine. Such delamination of the constitutive layers can result - amongst other drawbacks - in a reduced quality of the barrier properties of the package, and a reduced mechanical resistance of the whole package, which are of course undesirable.

In some prior art solutions, partial barriers were created by adding chemical additives to the pulp (e.g. Alkyl Ketene Dimers or "AKD") in order to create a barrier directly in the pulp layer of the package. However, these additives were found to be not sufficient to protect sensitive products, such as coffee for instance, which are very sensitive to oxidation and/or to moisture.

Having considered the above, there is a need for a process for making a package of cellulose pulp which comprises barrier to oxygen and/or moisture, and a package thus obtained, the making process and package thus obtained being deprived of the prior art drawbacks described above.

Summary of the invention

The primary objectives of the present invention are achieved with a process and a packaging item obtained with such a process, according to any of the related appended claims.

Especially, in a first aspect, the present invention concerns a process for manufacturing a tridimensional packaging item comprising at least two layers, one support cellulosic pulp layer, and one oxygen and/or moisture barrier layer, that comprises at least the steps of: i) providing a mold comprising at least two, male and female, cavities that are movable relative to one another, wherein the distance between the two cavities is regulated at micrometric scales, and both cavities comprising at least one liquid tight gas permeable portion connected to a vacuum source, ii) positioning the cavities at a distance (D) from each other that is comprised between 0.1 mm and 5 mm, so as to create a channel between the internal surfaces of said cavities, iii) immersing said in a first bath containing a first cellulosic pulp composition comprising a slurry of cellulosic fibres, and optionally polymers in fibres or polymer dispersion form, iv) applying vacuum through the wall of a first cavity within the channel to suck said first composition into the channel, and depositing solid material contained in said first composition onto the surface of said first cavity to create a cellulosic support layer, v) moving the cavities from one another, to maintain a distance between the surface of said solid material deposited on the first cavity and the surface of the second cavity, vi) immersing said mold in a second bath containing a second barrier composition (BC) comprising a slurry of cellulosic fibres and an organic polymer and/or inorganic material in fibres or polymer dispersion form, vii) applying vacuum through the wall of the second cavity within the channel, to suck said second composition (BC) into the channel, and depositing solid material contained in said second composition onto the surface of said second cavity, viii) circulating compressed air through the wall of the second cavity into the channel, to press said solid material containing the second composition onto the cellulosic support layer supported by said first cavity, so as to create a tridimensional multilayer solid item comprising superimposed cellulosic support layer and barrier layer, ix) separating the cavities and transferring the first cavity and the multilayer item to a dewatering oven and then to a drying press, x) detaching the dried solid item from the first cavity. The process according to the present invention involves the utilization of a mold comprising at least two cavities, movable relative to one another, wherein the distance between the two cavities is adjusted continuously during the bathing process, in order to allow deposition of the successive layers, bath in, bath out.

The molding equipment is generally of the type known in the prior art and will not be described in greater details therein.

The distance between the cavities is adjusted automatically, by any motorized or mechanical construction, e.g. via a cam path, or with motorized screw shafts adjustment. Generally, the distance increases between the two cavities, as additional layers are superimposed to form the packaging item and the thickness of the packaging wall thus obtained increases.

Duringthe manufacturing process, the distance between the cavities is always comprised between 0.1 mm and 5 mm, preferably between 0.5 and 2 mm, such that the slurry contained in the various baths, can flow between the cavities and be deposited in an even manner.

In one embodiment of the invention, the manufacturing process involves the creation of a third layer superimposed to the other two layers. This third layer comprises an aqueous dispersion coating of at least one ingredient selected within the list of: silica clay, silica oxide, aluminium oxide, siloxane oxide, or a combination thereof. The third composition can also comprise organic components, such as for example conventional or biodegradable polymers (polyolefins, Polybutylene adipate terephthalate (PBAT), Polycaprolactone (PCL), Polylactic acid (PLA), Polyvinyl Alcohol (PVOH), Ethylene Vinyl Alcohol (EVOH), Butenediol Vinyl Alcohol (BVOH), Polyhydroxyalcanoates (PHA), Polybutylene succinate (PBS), Polybutylene succinate adipate (PBSA), acrylic or methacrylic acid (co-)polymers, compounds or copolymers thereof, grafted or not with e.g. ionomers).

Optionally, binding agents may be included in at least one of the slurry compositions contained in a bath, such that such binding agents are present in any one of the different layers, to improve adhesion even further between at least two adjacent layers. Such binding agents are preferably mixed with cellulose pulp, under the form of aqueous dispersion, in the slurry batches.

In a second aspect, the present invention is directed to a packaging item obtained by the inventive process mentioned above.

More precisely, the inventive packaging item comprises at least two superimposed and partially intricated layers, said layers comprising in order from outside to inside of the packaging:

- A first cellulosic layer comprising cellulose pulp, and

- A second barrier layer comprising cellulosic pulp and at least one organic polymer and/or inorganic ingredient.

The resulting packaging is greatly improved because two consecutive layers impregnate each other therefore the adhesion between the layers and therefore improves the mechanical strength of the resulting package (resistance to delamination of the layers in particular).

In other terms, with the manufacturing process according to the invention, the different layers constitutive of the package are better "intricated" to one another. This results in a package having improved mechanical and oxygen/moisture barrier properties.

The packaging according to the present invention comprises at least two layers superimposed to one another:

- a cellulosic layer that comprises at least cellulose (hardwood or softwood), and at least one additional support ingredient selected within the list of: microfibrillated cellulose (MFC), Alkyl Ketene Dimers (AKD) - which is a water repellent -, starch - which provides mechanical strength -, dewatering agents, or a combination thereof, and - a barrier layer comprising a combination of cellulose and inorganic and/or organic components, selected within the list of: Polybutylene adipate terephthalate (PBAT), Polycaprolactone (PCL), Polylactic acid (PLA), Polyvinyl Alcohol (PVOH), Ethylene Vinyl Alcohol (EVOH), Butenediol Vinyl Alcohol (BVOH), Polyhydroxyalcanoates (PHA), polyolefins, metal oxides or metalloids, or a combination thereof.

Preferably, the cellulosic layer is the external layer (i.e. the layer opposite to the layer in contact with the packaging contents), and the barrier layer is the internal layer in contact with the packaging contents.

The overall thickness of polymer coating layers in the dry structure is extremely reduced (coating layers having a thickness of 2 to 15 microns should be obtained, preferably 5-10 microns) compared to the thickness of dried paper material (thickness between 0.15 and 3 mm), therefore the inventors have achieved to overcome the technical limitations of the known multilayer barrier structures, and achieve a packaging multilayer structure with excellent barrier properties against oxygen and moisture transfer, as well as resistance to liquid contact from their inner or outer surfaces, while achieving a total contents of cellulosic fibres of at least 85%, preferably of at least 95%, more preferably at least 99% of the overall material weight of said packaging item.

Furthermore, the organic and/or inorganic barrier polymer layer comprises very low amounts of organic and/or inorganic components and therefore is water soluble and allows recyclability in a paper recycling stream. The inventors succeeded in forming a multilayer structure with a ratio of cellulosic fibre to non- cellu losic material, which is extremely high in fibre contents, and wherein the polymer layers are easy to disintegrate in repulping process due to the high dispersibility and or solubility of organic and/or inorganic layer(s) in water. The resulting structure therefore demonstrates excellent repulping capabilities and high fibre yield of good quality which allows it to be accepted in standard recycled paper mills in most countries. The very low content of non-cellulosic polymer and/or inorganic (metal, metalloids) materials, makes the whole packaging of the invention easily disintegrated, dissolved and separated during recycling processes designed for cellulosic materials like paper or cardboard, unlike existing packages known from the art.

In a preferred embodiment of the invention, the inorganic layer comprises metals or metalloids selected within the list of: aluminium, aluminium oxide (AIOx), zinc oxide (ZnOx), silicon oxide (SiOx), Mica, Montmorillonite or (nano-)clay.

The present invention is primarily a molding process in one step for production of a multilayer pulp-based tridimensional item, and secondly, a packaging having improved adhesion between its constitutive layers.

However, in a third aspect, the invention concerns the use of a packaging item according to the invention, for packing an edible product for human or animal consumption, and in fourth aspect it concerns a packaged edible product, comprising a packaging item according to the invention that is filled with an edible product for food or animal consumption.

As used in this specification, the words "comprises", "comprising", and similar words, are not to be interpreted in an exclusive or exhaustive sense. In other words, they are intended to mean "including, but not limited to".

Brief description of the drawings

Additional features and advantages of the present invention are described in, and will be apparent from, the description of the presently preferred embodiments which are set out below with reference to the drawings in which: Figure 1 is a general schematic view showing a pulp forming machine comprising a bath filled with a first slurry composition of cellulose;

Figure 2 is a schematic perspective view of a molding block comprising six pairs of cavities for molding six items simultaneously;

Figure 3 is a schematic view of a pair of male and female cavities forming a mold, for molding a packaging item in a process according to the invention;

Figure 4 is a schematic perspective view of a male cavity for a mold as shown in figure 3;

Figures 5A and 5B are schematic cut views of a mold during molding of a first composition layer according to the invention;

Figures 6A and 6B are schematic cut views of a mold during molding of a second composition layer according to the invention;

Figure 7 is a schematic perspective view illustrating a packaging item obtained with a process according to the invention.

Detailed description of the invention

By "fibre", it is meant a cellulosic fibre, which is generally extracted from plants, seeds or trees; such fibres contain not only cellulose molecules, but also hemi-cellulose as well as lignin.

By "cellulosic pulp", it is meant a lignocellulosic fibrous material prepared by chemically or mechanically separating cellulose fibres from wood, fiber crops, waste paper, or rags.

MANUFACTURING TOOL

In figure 1 is depicted an embodiment of a molding machine 1 according to the invention. The molding machine comprises a slurry composition manufacturing section 2, and a forming section 3 where the forming tooling is located. The forming section 3 depicted in figure 1 comprises only one slurry composition bath 4, however, according to the principle of the invention, the forming section 3 actually comprises at least two independent slurry composition baths (other baths than the one illustrated in figure 1 are not shown in the drawing). Each one of the different baths composing the forming section 3 is filled with various compositions comprising cellulosic pulp fibres, preferably mixed with polymer dispersions to allow for multiple layers to be formed in the forming cavity into a tridimensional item, for instance a packaging item.

The slurry composition manufacturing section 2 comprises a mixing unit 4 for repulping cellulosic items such as recycled papers, wood items, etc. and further comprises a reactor 5 to produce a slurry composition having an homogenous and constant fiber concentration below 1% by weight. Several independent manufacturing sections (not illustrated in figure 1) can be used for simultaneously preparing various types of slurry compositions, or alternatively, the same manufacturing section 2 can be used to sequentially prepare various types of slurry compositions comprising different ingredients, as illustrated in figure 1.

Once a slurry composition is ready in the reactor 5, it can be sent to the forming section 3, through a network of pipes 6, for filling a dedicated bath (or "tank") 7.

In each bath, a mold block 8 comprising at least one mold can be immersed as shown in figure 1, wherein a tridimensional cellulosic pulp item is molded. Each molded item is then sent to a hot press unit 9, out of which finished and dried cellulosic tridimensional items 10 are produced and then stacked.

Having described the general set-up of the manufacturing equipment and the main manufacturing steps, the inventive process will now be described in more details. In figure 2, is illustrated an embodiment of the invention wherein a six-cavity mold block 8, comprises six individual molds 11 gathered in one casing 12. The mold casing 12 comprises upper 13 and lower 14 casing units, which respectively support upper cavities and lower cavities (by pairs) of each of the six individual mold 11. As shown in figure 2, the upper and lower cavities of each mold 11 is linked to a reversible gas circulation system through connections 15. Each cavity has its own independent connection 15 as illustrated in figure 2.

The upper and lower casing units 13, 14 are movable one relative to the other, such that the distance between the male and female cavities of each mold 11 can be adjusted continuously during the manufacturing process.

According to the invention, the intake of slurry into the molds is not performed by injection of said slurry into a closed mold, but by circulating said slurry composition in a space defined between the surfaces of said mold cavities, as they are kept distant from one another during bathing of said mold in a slurry composition bath 7 and because one of the cavities is connected to a gas circulation system, such that a vacuum is created at its surface that sucks said slurry composition from the bath into the mold towards the surface of the corresponding suction cavity. Depending on the slurry concentration and its viscosity, the distance between the two molds can be finely adjusted further.

In figures 3 and 4, is illustrated a mold 11 according to the invention which comprises a pair of cavities comprising an upper female cavity 16 and a lower male cavity 17. Cavities 16, 17 are represented in an open configuration of the mold. Each of the cavities 16 and 17 comprises a set of openings 18 at its surface each of which is connected through a network of channels 19 located in the mass of each cavity, to the reversible gas circulation system connections 15. Figure 4 illustrates in more detail the lower male cavity 17 comprising a set of openings 18 that are designed to create a vacuum or an overpressure at the surface of said male cavity 17. As an alternative to openings 18 as illustrated in figures 3 and 4, the surface of the cavities can be made out of sintered metal particles of stainless steel, nickel-alloy, copper, bronze, titanium.

The two cavities 16, 17 of each mold 11 are movable relatively one to another - as illustrated by a double-sided arrow - to allow for said cavities to be placed at a distance sufficient to let a slurry composition to circulate between said female and male cavities 16, 17 and settle at the surface of one cavity, according to the process steps that will be described in detail in the following.

As described above, according to the process of the invention, a mold 11 is submerged into a slurry composition bath, while the cavities of said mold are kept at a distance one from another that is sufficient to circulate said slurry composition between the two cavities, the circulation of said slurry composition being actuated from the bath into the cavity by a vacuum at the surface of at least one of the two cavities, and such that by deposition of the slurry composition at the surface of said at least one cavity, a tridimensional item is created. By closing the mold the tridimensional item is compressed and dewatered (i.e. the water present in the slurry composition making said item is removed), and then said item can be dried into a fully solid tridimensional item, for instance a packaging item.

When the cavity receives a new layer of material, the distance between the two cavities increase and the once the slurry is accumulated the cavities are compressed. Then compressed air is circulated on the side where the layer is being built to detach it from the cavity and repeat the operation.

PROCESS

The general principle of a molding process according to the invention consists of different steps taking place one after the other as described hereafter, using at least one mold with two cavities (male and female) that can be connected, where the distance between the two cavities can be regulated at micrometric scales (e.g. with 50 pm increments). At least one, but preferably both cavities are connected to a gas circulation source able to create a vacuum or an overpressure at the surface of the corresponding cavity.

Cavities are maintained at a distance from one another while they are immersed in baths containing different types of liquid slurry compositions. The preferred distance between the cavities during the slurry composition deposition process is comprised between 0.1 mm and 5 mm so as to create a channel between the cavities surfaces.

Once the cavities of a mold are immersed in a bath containing a slurry of pure cellulosic pulp fibres, or in a mixture of cellulosic pulp fibres and polymers, or in a pure polymer dispersion, and when vacuum is applied at the surface of one cavity, the channel between the cavities is filled up completely with the solid material contained in the slurry composition.

Then, the cavities are removed from the bath.

Optionally the mold is open widely such that the distance between the cavities is greater than 5 mm and then partial dewatering takes place. Then the mold is closed again as the two cavities are put together. In other words, once the suction is done, the cavities are slightly pressed to allow partial dewatering, then they are opened and the distance is adjusted, then they are reclosed to apply partial pressure. Then once the operations are completed, the cavities are separated, and the cavity where the item is supported is transferred in the hot press to dry.

Then the distance between the cavities is again adjusted to reflect the fact that material is deposited between them. The distance is adjusted though e.g. screwable shafts operated by an electric motor to create a new channel of desired thickness comprised between 0.1 and 5 mm. The full mold is immersed again in a new slurry bath that is filled with a different composition, vacuum is applied on the surface of at least one cavity of the mold, such that the composition circulates in the channel between the two cavities and is deposited on the surface where vacuum is applied.

Then air circulation at the surface of the cavity is inverted and instead of vacuum, compressed air is now circulated at the surface of the same cavity, to detach the wet object from one of the two cavities and transfer the other cavity to the hot press.

Then the cavities of the molds are fully separated, and the cavity supporting the multilayer molded item is transferred to a dewatering unit.

Some of the manufacturing steps mentioned above can be repeated several times, in order to add as many layers, one on top of the other, until the desired multilayer structure is obtained. For adding each layer onto the preceding ones, the mold is immersed in a dedicated new bath containing a slurry composition.

Finally, the dewatered multilayer molded item is transferred in a hot press unit heated at a temperature comprised between 100°C and 270°C (e.g. at 200°C) for a period of time comprised between 5 second and 10 minutes, for the final drying which provides a finished multilayer cellulose pulp molded tridimensional item.

The polymer will be applied through dispersion and particle size has to be bigger than mesh size of the cavity. Normally mesh size between 0.05 to 0.5 mm are used.

Having disclosed the general principle of the molding process according to the invention, a preferred embodiment will now be described more in detail. According to this embodiment as illustrated in figures 5A to 6B, the process comprises the steps of: i) providing a mold 11 (that can be part of a set of a plurality of molds) comprising first female, and second male cavities 16, 17 that are movable relative to one another, wherein the distance between the two cavities 16, 17 is regulated at micrometric scales, and both cavities comprising at least one liquid tight gas permeable portion connected to a vacuum source, ii) positioning the cavities 16, 17 at a distance (D) from each other that is comprised between 0.5 mm and 5 mm, as shown in figure 5A, so as to create a channel 20 between the internal surfaces of said cavities, iii) immersing said mold in a first bath containing a first cellulosic pulp composition comprising a slurry of cellulosic fibres, iv) applying vacuum (V) through openings 18 of the wall 21 of the female cavity 16 to suck said first composition into the channel 20, and depositing solid material contained in said first composition onto the surface of said female cavity 16 as shown in figure 5B to create a cellulosic support layer 22, v) moving the cavities 16, 17 from one another, to maintain a distance between the surface of said solid material deposited on the first cavity and the surface of the second cavity, that is comprised between 0.5 mm and 5 mm, vi) immersing said mold 11 in a second bath containing a second barrier composition (BC) comprising a slurry of cellulosic fibres and an organic polymer and/or inorganic material in fibres or polymer dispersion form, as illustrated in figure 6A, vii) applying vacuum (V) through the wall of the male cavity 17 as shown in figure 6A, to suck said second composition (BC) into the channel 20, and depositing solid material contained in said second composition onto the surface of said male cavity 17, viii) circulating compressed air C through the wall of the male cavity 17, into the channel 20, to press said solid material containing the second composition onto the cellulosic support layer supported by said first cavity, so as to create a tridimensional multilayer solid item comprising superimposed cellulosic support layer 22 and barrier layer 23, as illustrated in figure 6B, ix) separating the cavities and transferring the first cavity and the multilayer item to a dewatering oven and then to a drying press, x)detaching the dried solid tridimensional item from the first cavity.

MOLDED PACKAGING WITH BARRIER

During the deposition process of several layers one on top of the other as described above, the material constitutive of each layer is at least partially intricated with the material constitutive of the adjacent layer(s). This is particularly true for the cellulosic fiber material. Furthermore, at the time the cavities of the mold are closed, the multiple layers forming the item thus molded, are packed together tightly. Therefore, the adhesion between adjacent layers 22, 23 of the resulting tridimensional molded item 10, as shown in figure 7 is greatly improved versus the prior art molded items that are produced by thermoforming one additional layer (e.g. a barrier polymer layer) onto an already solid and dry mold pulp layer.

Applying the process according to the above described embodiment, to form a multilayer tridimensional item having a very high cellulosic pulp composition, one is capable of creating an item with a cellulose base substrate layer, and enrich this layer of cellulose with a very thin but homogeneous cellulose-polymer composite dispersion layer, or a pure polymer dispersion layer, in an organised superimposed but intricated manner that provides strong mechanical and barrier properties to the thus obtained tridimensional item. Such improved mechanical and oxygen/moisture barrier properties have proved to be particularly beneficial in the packaging applications which require a high bond strength between the adjacent layers of said packaging. This is especially the case for beverage capsules of the type used for preparing coffee or other beverages in beverage preparation machines, by piercing the wall of said capsule, and injecting a fluid (typically water) under pressure in said capsule or pod.

Claims

1. A process for manufacturing a tridimensional packaging item (10) comprising at least two layers, one support cellulosic pulp layer (22), and one oxygen and/or moisture barrier layer (23), said process comprising at least the steps of: i) providing a mold (11) comprising at least two, male and female, cavities (17, 16) that are movable relative to one another, wherein the distance (D) between the two cavities is regulated at micrometric scales, and both cavities comprising at least one liquid tight gas permeable portion connected to a vacuum source, ii) positioning the cavities (16, 17) at a distance (D) from each other that is comprised between 0.1 mm and 5 mm, so as to create a channel (20) between the internal surfaces of said cavities, iii) immersing said mold (11) in a first bath containing a first cellulosic pulp composition comprising a slurry of cellulosic fibres, and optionally polymers in fibres or polymer dispersion form, iv) applying vacuum (V) through the wall of a first cavity within the channel to suck said first composition into the channel (20), and depositing solid material contained in said first composition onto the surface of said first cavity to create a cellulosic support layer (22), v) moving the cavities (16, 17) from one another, to maintain a distance between the surface of said solid material deposited on the first cavity and the surface of the second cavity, vi) immersing said mold (11) in a second bath containing a second barrier composition (BC) comprising a slurry of cellulosic fibres and an organic polymer and/or inorganic material in fibres or polymer dispersion form, vii) applying vacuum (V) through the wall of the second cavity within the channel, to suck said second composition (BC) into the channel, and depositing solid material contained in said second composition onto the surface of said second cavity, viii) circulating compressed air (C) through the wall of the second cavity into the channel, to press said solid material containing the second composition onto the cellulosic support layer supported by said first cavity, so as to create a tridimensional multilayer solid item comprising superimposed cellulosic support layer (22) and barrier layer (23), ix) separating the cavities (16, 17) and transferring the first cavity and the multilayer item to a dewatering oven and then to a drying press, x) detaching the dried solid item (10) from the first cavity.

2. A process according to claim 1, which further comprises at least the following steps, between steps viii) and ix):

- moving the cavities from one another, to maintain a distance between the surface of said solid material deposited on the first cavity and the surface of the second cavity,

- immersing said mold in a third bath containing a third component composition comprising an aqueous dispersion coating of at least one ingredient selected within the list of: silica clay, silica oxide, aluminium oxide, siloxane oxide, or a combination thereof, or organic components selected within the list of: polyolefins, Polybutylene adipate terephthalate (PBAT), Polycaprolactone (PCL), Polylactic acid (PLA), Polyvinyl Alcohol (PVOH), Ethylene Vinyl Alcohol (EVOH), Butenediol Vinyl Alcohol (BVOH), Polyhydroxyalcanoates (PHA), Polybutylene succinate (PBS), Polybutylene succinate adipate (PBSA), acrylic or methacrylic acid (co-)polymers, compounds or copolymers thereof, grafted or not with e.g. ionomers, - applying vacuum through the wall of the second cavity within the channel, to suck said third composition into the channel, and depositing solid material contained in said third composition onto the surface of said second cavity,

- circulating compressed air through the wall of the second cavity into the channel, to press said solid material containing the third composition onto the barrier layer supported by said first cavity, so as to create a tridimensional multilayer solid item comprising superimposed cellulosic support layer, barrier layer, and protective layer.

3. A process according to any of the preceding claims 1 or 2, wherein the distance between the cavities is adjusted automatically, by a cam path or motorized screw adjustment mechanism.

4. A process according to any one of the preceding claims 1 to 3, wherein the mold comprises a plurality of molding blocks, each block comprising at least one male cavity and at least one corresponding female cavity.

5. A process according to any one of the preceding claims 1 to 4, wherein at least one of the slurry compositions comprises binding agents.

6. A process according to the preceding claim 5, wherein the binding agents are mixed with cellulose pulp, under the form of an aqueous dispersion, in the slurry composition.