WO2024188759A1

WO2024188759A1 - Method of production of a plurality of flat shaped aerosol generating substrates and associated tobacco article

Info

Publication number: WO2024188759A1
Application number: PCT/EP2024/055864
Authority: WO
Inventors: Sandra SPIELES; Alex HERRES
Original assignee: Jt International Sa
Priority date: 2023-03-10
Filing date: 2024-03-06
Publication date: 2024-09-19
Also published as: TW202435771A

Abstract

The present invention concerns a method of production of a plurality of flat shaped aerosol generating substrates, each aerosol generating substrate being usable with in a heat-not-burn aerosol generating device. The method comprises the following steps: - forming a mixture intended to form the aerosol generating substrates; - dosing the mixture in separate mould cavities of a mould (50), each mould cavity corresponding to a single aerosol generating substrate; - pressing and heating the mould (50) to form a plurality of single aerosol generating substrates of a desired shape and dimensions.

Description

Method of production of a plurality of flat shaped aerosol generating substrates and associated tobacco article

FIELD OF THE INVENTION

The present invention concerns a method of production of a plurality of flat shaped aerosol generating substrates.

An aerosol generating substrate formed according to the method is for example a solid substrate able to form aerosol when being heated. The substrate can be thus used to form a tobacco article, advantageously a flat shaped tobacco article.

The flat shaped tobacco article is operated with an aerosol generating device. Such type of aerosol generating devices, also known as heat-not-burn devices, is adapted to heat, rather than burn, the substrate by conduction, convection and/or radiation, to generate aerosol for inhalation.

BACKGROUND OF THE INVENTION

The popularity and use of reduced-risk or modified-risk devices (also known as vaporisers) has grown rapidly in the past few years as an aid to assist habitual smokers wishing to quit smoking traditional tobacco products such as cigarettes, cigars, cigarillos, and rolling tobacco. Various devices and systems are available that heat or warm vaporizable substances as opposed to burning tobacco in conventional tobacco products.

A commonly available reduced-risk or modified-risk device is the heated substrate aerosol generation device or heat-not-burn device. Devices of this type generate aerosol or vapour by heating an aerosol substrate that typically comprises moist leaf tobacco or other suitable vaporizable material to a temperature typically in the range 150°C to 350°C. Heating an aerosol generating substrate, but not combusting or burning it, releases aerosol that comprises the components sought by the user but not the toxic and carcinogenic byproducts of combustion and burning. Furthermore, the aerosol produced by heating the tobacco or other vaporizable material does not typically comprise the burnt or bitter taste resulting from combustion and burning that can be unpleasant for the user and so the substrate does not therefore require the sugars and other additives that are typically added to such materials to make the smoke and/or vapour more palatable for the user. Tobacco articles, usable with such type of aerosol generating devices can take various forms. Some of them can present an elongated stick or any other suitable shape, like for example a flat shape. Generally, such a tobacco article is received at least partially in a heating chamber of the device which comprises one or several heaters to heat the tobacco article.

A flat shaped tobacco article comprises a flat shaped aerosol generating substrate. Such a substrate can for example be produced using a forming process. In this case, a continuous substrate strip is formed by a press, e.g., with grooves and channels, and then cut into individual portions of aerosol generating substrates.

However, this production method is not fully satisfying. Particularly, after the cutting step, each individual portion should be weighted in order to match a target weight. When the target weight is not achieved, the portion is rejected or reused in the further production. As the portions of aerosol generating substrates are soft, the cutting step may also modify, even damage the formed shape of the individual portions. Additionally, different components used to form the substrate can be unevenly mixed in the substrate strip. This leads to uneven taste between different tobacco articles and as a consequence to a poor user experience.

SUMMARY OF THE INVENTION

One of the aims of the invention is to propose a method of production of a plurality of flat shaped aerosol generating substrates reducing considerably a waste rate during the production and allowing the production of tobacco articles improving the user experience.

For this purpose, the invention relates to a method of production of a plurality of flat shaped aerosol generating substrates, each aerosol generating substrate being usable with in a heat-not-burn aerosol generating device, the method comprising the following steps:

- forming a mixture intended to form the aerosol generating substrates;

- dosing the mixture in separate mould cavities of a mould, each mould cavity corresponding to a single aerosol generating substrate;

- pressing and heating the mould to form a plurality of single aerosol generating substrates of a desired shape and dimensions. Provided with these features, each portion of aerosol generating substrate can be formed individually with a high precision and consistency of the defined weight and the defined shape. Particularly, each mould cavity can be filled with a target portion of mixture intended to form a single aerosol generating substrate so as cutting and weighting steps are not necessary. After the pressing and heating step, the individual aerosol generating substrates can be released and directly used to form tobacco articles. Advantageously, the individual aerosol generating substrate is released from the mould and wrapped in a wrapper immediately after. Advantageously, no drying step is necessary after releasing the substrates from the mould.

Additionally, the mixture intended to form the substrates can be formed before the dosing step so as the components forming the mixture can be evenly distributed inside the mixture. This means that these components are also evenly distributed inside the resulting aerosol generating substrate that ensures homogeneous taste between different tobacco articles. Thus, the user experience can be improved.

According to some embodiments, the mixture comprises:

- 20-70% of an aerosol former;

- tobacco particles and/or inhalable agent;

- a gelling agent;

- optionally, a binder.

More generally, the mixture can form granular or crumbed structure. Advantageously, the mixture is a soft granular material.

The mixture can contain tobacco particles and/or inhalable agent which contains at least one stimulant, e.g., nicotine and/or flavour, aerosol former, and a gelling agent. The aerosol former may represent 20-70 wt. % in dry basis of the substrate. The gelling agent may represent between 1 -8 wt. % in dry basis. The gelling agent may be guar gum, gellan gum, non-protein polysaccharides and mixtures thereof. The gelling agent provides viscoelasticity to the substrate.

The substrate may further comprise a binder. The binder acts as a thickener. They increase the viscosity of the substrate, but the substrate still remains flowable for enabling the dosing of the mixture in the mould. The binder is preferably selected from: hydroxypropyl cellulose, variations of modified starch, cellulose ether such as carboxymethylcellulose, xanthan gum and combinations thereof .

The mixture may comprise solid tobacco comminuted to bring them to a particle size (D90) below 300 microns, advantageously between 50 and 1000 microns, and preferably between 60 and 220 microns. The tobacco particles may be mixed with aerosol former, the gelling agent, optionally binder and water. The water can be used to activate the binder. Preferably, the binder is carboxymethyl cellulose (CMC), more preferred carboxymethylcellulose sodium binder (Ceroga Roeper 4550 C; Cas. No. 9004-32-4).

In some embodiments, the dosing is performed in equal portions. For example, the weight of each portion can be comprised between 150 mg and 250 mg, and substantially equal to 200 mg.

Provided with these features, a mass production of tobacco articles can be carried out. Particularly, after releasing the aerosol generating substrates from the mould, these substrates can be directly used to form tobacco articles. In this case, a non-tobacco portion comprising for example a corrugated core can be attached to each aerosol generating substrate and a wrapper can fix both portions together. This reduces considerably the producing time and complexity of the tobacco articles.

According to some embodiments, the heating is performed until activating the binder comprised in the mixture.

Particularly, heated or boiling water contained in the mixture or water vaporization can activate the binder which forms the thickening stabilizer. Thus, the binder allows forming a relatively solid but still elastic structure of the aerosol generating substrate which can be directly used to form a tobacco article. Additionally, a drying step can be avoided.

Advantageously, the binder is activated only upon heating the mixture. This allows to avoid undesirable mixture solidification when for example the mixture is being stored or distributed.

According to some embodiments, the heating is performed after dosing the mixture in the mould. More preferably, the heating is performed during pressing the mould. Advantageously, before being filled with the mixture, the mould is unheated and presents for example an ambient temperature. The heating can be started simultaneously with the pressing the mould or shortly after pressing the mould, for example a few seconds after. In some other embodiments, the pressing is performed during a longer interval and then, the mould is heated. This interval can be adapted based on the mixture and/or dimensions and/or shape of the aerosol generating substrates. In some embodiment, a preheating phase is started simultaneously with the pressing or even before the pressing. In this case, an optimal temperature of the substrate can be achieved after the pressing.

Heating of the substrate can be performed in various ways. In some embodiments, the mould cavities are directly heated by an appropriate heating element. The heating element can for example comprises a plurality of heating parts, each heating part being associated to a mould cavity. Alternatively, the heating element presents one or several heating tracks extending through the mould. In some other embodiments, the mould are heated by heat transfer from the press. In this case, the press can present one or several contact surfaces configured to be in close contact with one or several surfaces of the mould. Both press and mould can be made or can comprise a material presenting high heat conducting properties such as a metal. Other heat techniques can also be used. For example, the mould can be heated by induction and/or radiation.

The heating temperature of the substrate during the pressing and heating step is comprised between 70°C and 120°C, advantageously between 75°C and 100°C. To achieve this temperature of the substrate, the mould can be heated to a greater temperature, for example a temperature comprised between 80°C and 120°C. It can be substantially equal to 1 10°C, for example.

More generally, the heating temperature is adapted to activate the binder in each mould cavity. For example, when the binder is adapted to be activated by heating water contained in the substrate to a temperature close to the boiling point of water (e.g., close to or at 100°C). As moisture evaporates, it activates the binder and the shape becomes rigid yet still elastic.

In some embodiments, the pressure exerted on the mould during the pressing and heating step is comprised between 5 and 15 bars, advantageously between 3 and 5 bars. Preferably, the substrate is pressed to a maximum thickness of 3 mm, most preferably between 1 ,5 and 2,5 mm. In some embodiments, the pressure is exerted on the mould during a pressing time comprised between 30 s and 120 s, and advantageously equal to 60 s. The time range may be important for achieving the proper texture of the substrate. If time is too high, the substrate may dry and become brittle. Also, the liquids may drain out of the mould. If the time is too low, the binding process may not have ended, and parts of the substrate may be too crumbled and fall apart.

These pressure values and duration ensure optimal results in producing the aerosol generating substrates. Additionally, these values can vary based on the mixture used to form the aerosol generating substrates as well as on shape and dimensions of the aerosol generating substrates.

In some embodiments, each mould cavity is delimited by a pair of opposite surfaces, at least one opposite surface having at least one protruding part to form at least one airflow channel on a surface of the corresponding aerosol generating substrate.

Provided with this features, at least one opposite surface of the mould cavity has a shape complementary to the shape of the corresponding surface of the aerosol generating substrate. Thus, airflow channels can be easily formed on this surface without any other additional step.

In some embodiments, each opposite surface has at least one protruding part arranged in offset with the corresponding protruding part of the other surface, to form a corrugated shape of the aerosol generating substrate.

A corrugated shape of the aerosol generating substrate is particularly advantageous since it allows the increase of the heating surface and accordingly even heating of the substrate. Thus, the airflow passing through the substrate can evenly extract the flavour from the substrate during the whole vaping session.

In some embodiments, each mould cavity has a substantially rectangular shape.

Particularly, each mould cavity has a substantially flat rectangular shape. Provided with this shape, the aerosol generating substrate can be used to form a flat shaped tobacco article. A tobacco article having such a shape is particularly advantageous since its pre- heating phase can be considerably reduced in comparison with articles having conventional shapes (cylindrical for example). Additionally, a flat shaped tobacco article can be efficiently heated from both sides so as to ensure a reach vapour generation during the whole vaping session.

In some embodiments, the mould cavities are arranged to form at least two columns and at least two lines on the mould.

In other words, the mould cavities can form a matrix structure in the mould. The cavities can be distanced by a same distance according to both directions or at least one direction of the matrix structure.

The matrix structure is advantageous during the dosing step of the mixture. For example, one or several dosing nozzles can be used to distribute the mixture during the dosing step. The nozzles can be moveable or fixed. They can be arranged so as to match the centre of each moulding cavity for filling with the mixture. For example, the nozzles can be aligned according to one direction of the matrix structure and can be moveable according to the other direction. In variant, the mould can be mounted on a moveable platform to be moveable in respect with the nozzles.

According to some embodiments, the mould forms two opposite parts distanced by a predetermined distance in a closed position of the mould, during the heating and pressing step to form a flat-shaped aerosol generating substrate.

The predetermined distance can be chosen based on the desired thickness of the aerosol generating substrate. Thus, it is possible to obtain a flat shaped aerosol generating substrate. A limiter inserted in one of the parts of the mould can be used to maintain the predetermined distance between the parts of mould while pressure is being exerted to maintain the mould in the closed position. The limiter can further form a grid structure so as to delimit laterally the mould cavities. The limiter can be solidary attached to the corresponding part of the mould.

One of the parts of the mould can form a male part and the other, a female part. The female part can be provided with a plurality of recesses forming partially the mould cavities while the male part can be provided with a plurality of protrusions. Each protrusion can face a recess and when it is received in this recess, forms together with the recess the corresponding mould cavity. The limiter can be arranged in the female part so as to form the recesses.

The invention also concerns a tobacco article configured to operate with an aerosol generating device and comprising:

- a tobacco portion comprising a flat shaped aerosol generating substrate produced by a method as defined above;

- a non-tobacco portion extending the tobacco portion.

The invention also concerns an aerosol generating system comprising:

- a tobacco article as defined above;

- an aerosol generating device configured to operate with the tobacco article.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention and its advantages will be better understood upon reading the following description, which is given by way of non-limiting examples and which is made with reference to the appended drawings, in which:

- Figure 1 is a perspective view of an aerosol generating system comprising an aerosol generating device and a tobacco article according to the invention, the tobacco article being usable with the aerosol generating device;

- Figure 2 is a perspective view of the tobacco article of Figure 1 , the tobacco article comprising an aerosol generating substrate;

- Figure 3 is a perspective view of the aerosol generating substrate of Figure 2;

- Figure 4 is a perspective view of the mould used to form the aerosol generating substrate of Figure 3;

- Figure 5 is a top view of a part of the mould of Figure 4; and

- Figure 6 is a cross-sectional partial view of the mould of Figure 4.

DETAILED DESCRIPTION OF THE INVENTION Before describing the invention, it is to be understood that it is not limited to the details of construction set forth in the following description. It will be apparent to those skilled in the art having the benefit of the present disclosure that the invention is capable of other embodiments and of being practiced or being carried out in various ways.

As used herein, the term “aerosol generating device” or “device” may include a vaping device to deliver an aerosol to a user, including an aerosol for vaping, by means of a heater element explained in further detail below. The device may be portable. “Portable” may refer to the device being for use when held by a user. The device may be adapted to generate a variable amount of aerosol, e.g. by activating the heater element for a variable amount of time (as opposed to a metered dose of aerosol), which can be controlled by a trigger. The trigger may be user activated, such as a vaping button and/or inhalation sensor. The inhalation sensor may be sensitive to the strength of inhalation as well as the duration of inhalation to enable a variable amount of vapour to be provided (so as to mimic the effect of smoking a conventional combustible smoking article such as a cigarette, cigar or pipe, etc.). The device may include a temperature regulation control to drive the temperature of the heater and/or the heated aerosol generating substance (aerosol pre-cursor) to a specified target temperature and thereafter to maintain the temperature at the target temperature that enables efficient generation of aerosol.

As used herein, the term “aerosol” may include a suspension of vaporizable material as one or more of: solid particles; liquid droplets; gas. Said suspension may be in a gas including air. Aerosol herein may generally refer to/include a vapour. Aerosol may include one or more components of the vaporizable material.

As used herein, the term “vaporizable material” or “precursor” may refer to a smokable material which may for example comprise nicotine or tobacco and an aerosol former. Tobacco may take the form of various materials such as shredded tobacco, granulated tobacco, tobacco leaf and/or reconstituted tobacco. Suitable aerosol formers include: a polyol such as sorbitol, glycerol, and glycols like propylene glycol or triethylene glycol; a non-polyol such as monohydric alcohols, acids such as lactic acid, glycerol derivatives, esters such as triacetin, triethylene glycol diacetate, triethyl citrate, glycerin or vegetable glycerin. In some embodiments, the aerosol generating agent may be glycerol, propylene glycol, or a mixture of glycerol and propylene glycol. The substrate may also comprise at least one of a gelling agent, a binding agent, a stabilizing agent, and a humectant.

Figure 1 shows an aerosol generating system 10 comprising an aerosol generating device 11 and a tobacco article 12, also called consumable article 12. The aerosol generating device 1 1 is intended to operate with the tobacco article 12 which is shown in more detail in Figure 2.

Referring to Figure 1 , the aerosol generating device 11 comprises a device body 15 extending along a device axis Y. The device body 15 comprises a mouthpiece 16 and a housing 17 arranged successively along the device axis Y. According to the example of Figure 1 , the mouthpiece 16 and the housing 17 form two different pieces. Particularly, according to this example, the mouthpiece 16 is designed to be fixed on or be received in an insertion opening formed at one of the ends of the housing 17. In this case, the tobacco article 12 can be inserted inside the device 1 1 when the mouthpiece 16 is removed from the housing 17. According to another example (not-shown), the mouthpiece 16 and the housing 17 form one unique piece. In this case, the tobacco article 12 can be inserted inside the device 1 1 through for example an outlet hole. According to both examples, the mouthpiece 16 defines a through hole adapted to receive at least partially the tobacco article 12. Particularly, the through hole can be adapted to receive at least a mouth end of the tobacco article 12, explained in further detail below. According to still another embodiment (not-shown), no mouthpiece 16 is provided with the aerosol generating device 11. In this case, the mouth end of the tobacco article 12 can form a mouthpiece designed to be in contact with the user’s lips and/or mouth while a vaping session.

The housing 17 delimits an internal space of the device 11 receiving various elements designed to carry out different functionalities of the device 1 1. This internal space can for example receive a battery for powering the device 11 , a control module for controlling the operation of the device 1 1 , a heating chamber for heating the tobacco article 12, etc. Particularly, the heating chamber is designed to receive at least partially the tobacco article 12. In the example of Figure 1 , the heating chamber may be for example arranged in the extension of the through hole of the mouthpiece 16, according to the device axis Y. The heating chamber may for example present a cup shape and comprises a heater designed to heat at least a part of the tobacco article 12. The heater comprises for example a pair of heating plates facing each other and designed to heat opposite walls of the tobacco article 12. In reference to Figure 2, the tobacco article 12 is a flat-shaped cuboid extending along an article axis X between an inlet end 18 and a mouth end 19, and having external dimensions LxWxD. In a typical example, the length L of the article 12 according to the article axis X equals substantially to 33 mm while its width W and depth D are substantially equal respectively to 12 mm and 1 ,2 mm. According to different examples, the values L, W and D can be selected within a range of +/- 40%, for example. The depth D of the tobacco article 12 is formed by a pair of parallel walls 23A, 23B, called hereinafter lateral walls 23A, 23B, and the width W of the tobacco article 12 is formed by a pair of parallel walls 24A, 24B, called hereinafter wider walls 24A, 24B. Each wider wall 24A, 24B is for example at least 5 times, advantageously 10 times, wider than each lateral wall 23A, 23B. The flat shape of the tobacco article 12 is thus defined by the ratio between each wider wall 24A, 24B and each lateral wall 23A, 23B, which is greater than 5, advantageously greater than 10. In some embodiments, the edges between the wide and lateral walls 23A, 23B, 24A, 24B can be rounded. According to other embodiments of the invention, the tobacco article 12 can have any other suitable flat shape and/or external dimensions.

The tobacco article 12 comprises a tobacco portion 25 and a non-tobacco portion 26 arranged successively with the tobacco portion 25 along the article axis X. The tobacco portion 25 may for example be slightly longer than the non-tobacco portion 26. For example, the length L2 of the tobacco portion 25 according to the article axis X may be substantially equal to 18 mm and the length L1 of the non-tobacco portion 26 according to the article axis X may be substantially equal to 15 mm. The tobacco portion 25 defines the inlet end 18 of the article 12 and the non-tobacco portion 26 defines the mouth end 19 of the article 12. The tobacco portion 25 and the non-tobacco portion 26 may be fixed one to the other by a wrapper 31 extending around the article axis X. In this case, the wrapper 31 forms the lateral and wider walls 23A, 23B, 24A, 24B of the tobacco article 12. In some embodiments, the wrapper 31 is formed from a same wrapping sheet. In some other embodiments, the wrapper 31 is formed from separate wrapping sheets wrapping separately the portions 25, 26 and fixed one to the other by any other suitable mean. The wrapper 31 may, for example, comprise paper and/or non-woven fabric and/or aluminium foil. The wrapper 31 may be porous or air impermeable. In some embodiments, when the wrapper 31 comprises aluminium, the aluminium can wrap only the aerosol generating substrate explained in further detail below, to prevent condensation leakage and/or vapour leakage. In an embodiment, the wrapper is a laminate of paper and aluminium which extends along the full length of the article axis X. Additionally, aluminium allows a better heat transfer. In some embodiments, the tobacco article 12 can be provided and used without the wrapper 31 .

The part of each wider wall 23A, 23B corresponding to the tobacco portion 25 of the article 12 is designed to be heated by the heating chamber of the device 1 1. Particularly, each of these parts is designed to be in contact with the heating plate forming the heater, as explained above. In some embodiments, the corresponding part of only one of the wider walls 23A, 23B is designed to be heated by the heater.

The non-tobacco portion 26 comprises a core 37 intended to act for example as a cooler and/or filter to cool and/or filter the vapour before it is inhaled by the user. The core 37 may comprise for example corrugated paper. The core 37 may be formed through an extrusion and/or rolling process into a stable shape. Advantageously, the core 37 is arranged inside the non-tobacco portion 26 to be entirely in contact with the internal surface of the wrapper 31 delimiting this non-tobacco portion 26. In some embodiments, no core is provided and the non-tobacco portion 26 can for example be hollow. Still according to some other embodiments, no non-tobacco portion 26 is provided and the tobacco article 12 is formed by the tobacco portion 25.

The tobacco portion 25 comprises an aerosol generating substrate 32 containing a vaporizable material as defined above. The vaporizable material is for example compressed to form a solid structure which is able to release aerosol upon heating.

As shown in Figure 3, the aerosol generating substrate 32 defines for example a generally flat-shaped cuboid defining a pair of opposite lateral surfaces 33A, 33B (represented as the right and left sides of the substrate in Figure 3), and a pair of opposite wider surfaces 34A, 34B (represented as the top and bottom sides in Figure 3), each of said surfaces extending along the article axis X. The lateral surfaces 33A, 33B and the wider surfaces 34A, 34B form an external surface of the substrate 32. When the tobacco article 12 is in use in the device, the wider surfaces 34A, 34B are positioned in close contact with the heating elements of the device so as to be heated by the heater element, e.g., with the wrapper positioned in-between. In the embodiments where the tobacco article 12 comprises the wrapper 31 , the lateral surfaces 33A, 33B are adjacent at least partially to the internal surface of the lateral walls 23A, 23B formed by the wrapper 31 and the wider surfaces 34A, 34B are adjacent partially to the internal surface of the wide walls 24A, 24B formed by the wrapper 31. The aerosol generating substrate 32 further defines a pair of transversal surfaces 36A, 36B (represented as the back and front sides of the substrate in Figure 3) extending transversally to the article axis X. The transversal surface 36A forms the inlet end 18 of the tobacco article 12 and the transversal surface 36B is adjacent to the non-tobacco portion 26 of the tobacco article 12.

At least one of the wider surfaces 34A, 34B, advantageously each wider surface 34A, 34B, of the aerosol generating substrate 32 defines one or a plurality of grooves extending between the transversal surfaces 36A, 36B. Each groove forms an airflow channel designed to conduct an airflow along the corresponding wider surface 34A, 34B.

Each airflow channel can extend generally along the article axis X which means that the airflow conducted by this airflow channel is mainly directed from the inlet end 18 to the non-tobacco portion 26. At least some of the airflow channels can be rectilinear and/or at least some of the airflow channels can be curvilinear. At least some of the airflow channels can present a variable cross-sectional dimension and/or shape along their length. Particularly, the groove’s width and/or depth of forming an airflow channel can vary along the length of this channel. The cross-sectional shape of the groove can also vary. For example, in some cross-sections the groove can have a rounded shape and in some other cross-sections a rectangular shape. The variation of the shape and/or dimensions can be smooth (gradual) or discontinuous. Additionally, at least some airflow channels can be split in two or more sub-channels.

In the example of Figure 3, three airflow channels 40A, 40B are formed on each wider surface 34A, 34B. These airflow channels are rectilinear and define a substantially constant cross-section along their length. Additionally, the airflow channels 40B of the wider surface 34B are in offset in transversal direction in respect with the airflow channels 40A of the wider surface 34A. Thus, in this example, the aerosol generating substrate 32 defines a corrugated shape when viewed in the transversal plane perpendicular to the article axis X.

To produce a plurality of aerosol generating substrates 32 according to the method of production explained in further detail below, a mould 50 is used. An example of such a mould 50 is shown in Figure 4. The mould 50 comprises a plurality of mould cavities 52. Each mould cavity 52 (shown in Figure 6) is designed to form a single aerosol generating substrate 32. For example, the mould 50 can form a substantially rectangular shape and comprise a plurality of mould cavities 52 forming a two-dimensional matrix structure. Thus, for example, the mould 50 can form 48 mould cavities forming 6 lines and 8 columns, as it is shown in Figure 5. The mould cavities 52 can be evenly spaced between them according to each direction of the matrix structure. The distance d between each pair of the mould cavities 52 can for example be comprised between 2 and 10 mm, advantageously between 3 and 9 mm, and can for example be equal to 4,5 mm. The mould 50 can be done from or comprise a metal material ensuring a good heat transfer.

The mould cavities 52 have substantially the same shape and dimensions. Each mould cavity 52 is delimited by a pair of opposite surfaces 54A, 54B. Each opposite surface 54A, 54B has a shape adapted to form the corresponding wider surface 34A, 34B of the aerosol generating substrate 32. Particularly, each opposite surface 54A, 54B has a shape complementary to the shape of the corresponding wider surface 34A, 34B of the aerosol generating substrate 32. Thus, each opposite surface 54A, 54B comprises at least one protruding part 55 intended to form a groove of the corresponding wider surface 34A, 34B. When the mould cavity 52 is intended to form an aerosol generating substrate 32 as shown in Figure 3, the protruding parts 55 of the opposite surfaces 54A, 54B are in offset in respect to each other to form a corrugated cross-sectional shape of the aerosol generating substrate 32, as explained in reference to Figure 3.

The mould 50 comprises two facing parts 60A, 60B forming between them the mould cavities 52 as explained above. The facing parts 60A, 60B are moveable between an open position in which the mould 50 can be filled with the mixture intending to form the aerosol generating substrates, and a closed position in which the facing parts 60A, 60B are distanced one from the other by a predetermined distance D (shown in Figure 6). This distance D is chosen based on the desired thickness of the aerosol generating substrates 32. The facing parts 60A, 60B can be maintained in the closed position by a press (not shown) adapted to exert a predetermined pressure on each side of the mould 50.

In the example of Figures 4 to 6, the mould 50 forms a female part 60B and a male part 60A. As it is shown in further detail in Figure 5 illustrating a top view of the female part 60B, the female part 60B forms a plurality of recesses 62 delimited laterally by a grid structure forming a limiter 64. The distance D between the parts 60A, 60B in the closed position can be controlled by the limiter 64. This distance D can for example be substantially equal to 3 mm or most preferably comprised between 1 ,5 and 2,5 mm The male part 60A comprises a plurality of protrusions 66 arranged to face the recesses 62. Each protrusion 66 is designed to be received in the corresponding recess 62 so as to form a mould cavity 52 as explained below. Particularly, each mould cavity 52 is delimited by the corresponding recess 62 and protrusion 66 on its bottom and top, and laterally by the limiter 64. In some embodiments, the protrusions 66 can be dimensioned to enter laterally in contact with the limiter 64 or to form a gap with the limiter 64 that cannot be crossed by the tobacco dough.

In some embodiments, the mould 50 can be provided with a heating element configured to heat each mould cavity 52. According to different examples of these embodiments, the heating element can comprise for example a plurality of heating parts, each heating part being arranged adjacent to the corresponding mould cavity 52 and configured to heat this cavity 52. The heating parts can for example be connected electrically between them. According to another example, the heating element comprises a single heating part (for example one or several heating tracks) arranged along a surface of the mould to ensure a homogenous heating of the mould cavities 52.

In some other embodiments, the mould 50 is provided without heating element. In this case, the mould 52 can be heated by heat transfer from the press or using any other appropriate heating means such as induction or radiant heater(s).

A method of production used to manufacture a plurality of aerosol generating substrates 32 comprised in the tobacco article 12 will now be explained.

This method comprises an initial step of forming a mixture intended to form the aerosol generating substrates 32, for example at least 48 or 64 aerosol generating substrates 32. More generally, the amount of mixture is determined so as to fill at least one mould 50, as it will be explained below. More preferably, the amount of mixture is determined so as to fill several moulds 50.

This mixture can for example be in a form of tobacco dough. The tobacco dough may be a substrate containing tobacco particles and/or inhalable agent which contains at least one stimulant, e.g., nicotine and/or flavour, aerosol former, and a gelling agent and optionally a binder. The aerosol former may represent 20-70 wt. % in dry basis of the substrate. The gelling agent may represent between 1 -8 wt. % in dry basis of the aerosol generating substrate. The gelling agent may be guar gum, gellan gum, non-protein polysaccharides and mixtures thereof. The substrate may further comprise a binder or degradation preventing and/or thickening stabilizer such as hydroxypropyl cellulose, variations of modified starch, cellulose ether such as carboxymethylcellulose, xanthan gum and combinations thereof. The substrate can be a crumbed aerosol generating substrate wherein the aerosol releasing substrate has a soft granular texture such as described in WO2021094366. An example of pressed aerosol generating substrate is described in WO2021094365. The mixture may comprise solid tobacco comminuted to bring them to a particle size (D90) below 300 microns, advantageously between 50 and 1000 microns, and preferably between 60 and 220 microns. The tobacco particles may be mixed with aerosol former, the gelling agent, optionally stabilizer and water. A tobacco dough of water content below 50 wt. %, e.g., of about 30-40 % can be obtained. The production of the tobacco dough may be carried out as described in EP 3852554. The water is used to activate the binder, which together form the thickening stabilizer. Preferably, the binder is carboxymethyl cellulose (CMC), more preferred Ceroga Roeper 4550 C (Cas. No. 9004-32-4).

Preferably, the mixture presents an even distribution of tobacco particles and other particles composing this mixture. For this purpose, the components of the mixture can be first put in a mixture bowl and a mixing mechanism can be activated to mix these components until achieving a mixture with evenly distributed particles.

In some cases, the mixture can be stored before being used during the next step. It can for example be stored for a duration comprised between 1 and 48 hours, for example for a duration of 24 hours. The storing temperature can be adapted to avoid binder activation. For example, the storing temperature can be below 40°C.

During the next step, a mould 50 as explained above is provided for example in the open position. The mould 50 can be unheated, i.e. present the ambient temperature. Then, a dosing mechanism distributes the mixture prepared during the previous step among the mould cavities 52 of the mould 50. Particularly, the dosing mechanism distributes in each mould cavity 52 a predetermined portion of the mixture which is intended to form a single aerosol generating substrate 32. This portion has for example a weight greater than 50 mg, preferably greater than 100 mg, more preferably greater than 150 mg and/or lower than 400 mg, preferably lower than 350 mg, more preferably lower than 300 mg. Advantageously, the portion weight is comprised between 150 mg and 250 mg, and is substantially equal to 200 mg. To distribute the mixture, the dosing mechanism can comprise a dosing nozzle moveable between the recesses 62 formed by the female part 60B of the mould 50 and distributing in each recess 62 the predetermined portion of the mixture. In some embodiments, the dosing mechanism can comprise a plurality of dosing nozzles. These nozzles can be aligned and able to move according to a single direction. This direction can correspond to one of the directions of the matrix structure of the mould 50. In this case, the dosing nozzles are aligned according to the other direction and their number corresponds to the number of the mould cavities 52 in the matrix structure according to this direction. According to still another embodiment, the dosing nozzles are fixed and the female part 60B is positioned so as each recess 62 faces a corresponding dosing nozzle. In this case, the number of the dosing nozzles corresponds to the number of the mould cavities 52 in the mould 50. Of course, instead of one or several moveable dosing nozzles, the female part 60B of the mould 50 can be mounted on a moveable platform according to one or two directions.

During the next step, the mould 50 is closed and the press is actuated to maintain the mould 50 in the closed position. When for example the mould 50 of Figure 4 is used, the male part 60A can cover the female part 60B and be distanced from it according to the predetermined distance, as explained above. The press can for example exert pressure on opposite surfaces of the mould 50 comprised between 5 and 15 bars, advantageously between 3 and 5 bars.

Substantially at the same time or shortly after (for example 1 or 2 seconds after) actuating the press, the mould cavities 52 are heated to activate the binder in the mixture. Particularly, heated or boiling water of the mixture can activate the binder which forms the thickening stabilizer. According to different embodiments of the invention, the mould cavities 52 can be heated directly by the heating element associated to the cavities or by heat transfer from the press. In this last case, the press defines for example at least two contact surfaces configured to be in a close contact with opposite sides of the mould and provided with a heater. Heat can be thus transferred from the contact surfaces to the mould. The heating temperature of the substrate is for example comprised between 70°C and 120°C, advantageously between 75°C and 100°C. The heating temperature may not necessarily be constant. A profile of temperatures may be provided such that the substrate reaches a temperature close to the boiling point of water at least during a certain period of time. The pressure can be exerted on the mould during a pressing time comprised between 30 s and 120 s, and advantageously equal to 60 s.

At the end of this step, the mould is opened and the individual aerosol generating substrates 32 are realised. After, each of the aerosol generating substrates can be fixed with a non-tobacco portion by a wrapper to form a tobacco article 12.

Claims

1 . A method of production of a plurality of flat shaped aerosol generating substrates (32), each aerosol generating substrate (32) being usable with in a heat-not-burn aerosol generating device (1 1 ), the method comprising the following steps:

- forming a mixture intended to form the aerosol generating substrates (32);

- dosing the mixture in separate mould cavities (52) of a mould (50), each mould cavity (52) corresponding to a single aerosol generating substrate (32);

- pressing and heating the mould (50) to form a plurality of single aerosol generating substrates (32) of a desired shape and dimensions.

2. The method according to claim 1 , wherein the mixture comprises:

- 20-70% of an aerosol former;

- tobacco particles and/or inhalable agent;

- a gelling agent;

- optionally, a binder.

3. The method according to claim 1 or 2, wherein the dosing is performed in equal portions in the mould cavities (53).

4. The method according to claim 3, wherein the weight of each portion is comprised between 150 mg and 250 mg, and is substantially equal to 200 mg.

5. The method according to any one of the preceding claims, wherein the heating is performed until activating a binder comprised in the mixture.

6. The method according to any one of the preceding claims, wherein the heating is performed during pressing the mould (50).

7. The method according to any one of the preceding claims, wherein:

- the heating temperature during the pressing and heating step is comprised between 70°C and 120°C, advantageously between 75°C and 100°C; and/or

- the pressure exerted on the mould (50) during the pressing and heating step is comprised between 3 and 5 bar and/or

- the substrate is pressed to a maximum thickness (D) of 3 mm, most preferably between 1 ,5 and 2,5 mm.

8. The method according to any one of the preceding claims, wherein the pressure is exerted on the mould (50) during a pressing time comprised between 30 s and 120 s, and advantageously equal to 60 s.

9. The method according to any one of the preceding claims, wherein the mould cavities (52) have a substantially same shape and dimensions.

10. The method according to any one of the preceding claims, wherein each mould cavity (52) is delimited by a pair of opposite surfaces (54A, 54B), at least one opposite surface (54A, 54B) having at least one protruding part (55) to form at least one airflow channel (40A, 40B) on a surface of the corresponding aerosol generating substrate (32).

11 . The method according to claim 10, wherein each opposite surface (54A, 54B) has at least one protruding part (55) arranged in offset with the corresponding protruding part (55) of the other surface (54A, 54B), to form a corrugated shape of the aerosol generating substrate (32).

12. The method according to any one of the preceding claims, wherein each mould cavity (52) has a substantially rectangular shape.

13. The method according to claim 12, wherein the mould cavities (52) are arranged to form at least two columns and at least two lines on the mould (50).

14. The method according to any one of the preceding claims, wherein the mould (50) forms two opposite parts (60A, 60B) distanced by a predetermined distance (D) in a closed position of the mould (50), during the heating and pressing step to form a flat-shaped aerosol generating substrate (32).

15. A tobacco article (12) configured to operate with an aerosol generating device (1 1 ) and comprising:

- a tobacco portion (25) comprising a flat shaped aerosol generating substrate (32) produced by a method according to any one of the preceding claims;

- a non-tobacco portion (26) extending the tobacco portion (25).