WO2023275318A1

WO2023275318A1 - Flat tobacco article comprising at least two layers and aerosol generating device with such an article

Info

Publication number: WO2023275318A1
Application number: PCT/EP2022/068185
Authority: WO
Inventors: Yasuhiro Miyatani
Original assignee: Jt International S.A.
Priority date: 2021-06-30
Filing date: 2022-06-30
Publication date: 2023-01-05
Also published as: EP4362717A1; KR20240027610A

Abstract

Flat-shaped tobacco article configured to receive at least a part of a double-sided flat heater and aerosol generating assembly comprising such an article The present invention concerns a flat- shaped tobacco article (12) comprising a first heating portion (81) and a second heating portion (82) designed to be arranged parallel to the first heating portion (81); the first heating portion (81) comprising a substrate layer (91) comprising tobacco substrate; the second heating portion (82) comprising a retainer layer (92) comprising a vapour forming agent and an agent retainer retaining the vapour forming agent; the flat-shaped tobacco article (12) being configured to receive at least a part of a double-sided flat heater (47) of an aerosol generating device between the first and the second heating portions (81, 82) to heat simultaneously each of the heating portions (81, 82). Said substrate layer (91; 94A) and retainer layer (92; 93C) of the first heating portion (81) and the second heating portion (82) respectively are arranged to be heated directly by the corresponding side of the flat heater (47).

Description

FLAT TOBACCO ARTICLE COMPRISING AT LEAST TWO LAYERS AND AEROSOL GENERATING DEVICE WITH SUCH AN ARTICLE

FIELD OF THE INVENTION

The present invention concerns a flat-shaped tobacco article configured to receive at least a part of a double-sided flat heater.

The present invention also concerns an aerosol generating assembly comprising such an article and an aerosol generating device configured to operate with this article. The tobacco article comprises for example a solid substrate able to form aerosol when being heated. Thus, the aerosol generating device configured to operate with the article, also known as a heat-not-burn device, 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 comprised in a tobacco article usable with such type of devices. The aerosol substrate 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 substrate, but not combusting or burning it, releases aerosol that comprises the components sought by the user but not the toxic and carcinogenic by-products 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. It is clear therefore that the aerosol generation from the substrate through the whole vaping session presents a challenging issue. For example, in some cases, the aerosol substrate can generate vapour at the beginning of the session and can be exhausted at the end. Thus, the quantity of vapour generated during the session can vary significantly that can cause undesirable user experience. Additionally, in some aerosol generating devices, heat transfer from the heater to the substrate is not optimal. In this case, the heat is wasted or a large amount of insulator materials is used to avoid heat leakage.

SUMMARY OF THE INVENTION

The present invention aims to propose a tobacco article for using with a heat-not- burn device which can provide a better user experience during the whole vaping session. Particularly, the invention aims to enhance and make it last during the whole vaping session aerosol generation ensured by a tobacco article when it is used with a heat-not-burn device. Additionally, the invention ensures an optimal heat transfer from the heater to the tobacco article so as to avoid heat wasting or using a large amount of insulators.

For this purpose, the invention relates to a flat-shaped tobacco article comprising a first heating portion and a second heating portion designed to be arranged parallel to the first heating portion; the first heating portion comprising a substrate layer comprising tobacco substrate; the second heating portion comprising a retainer layer comprising a vapour forming agent and an agent retainer retaining the vapour forming agent; the flat-shaped tobacco article being configured to receive at least a part of a double sided flat heater of an aerosol generating device between the first and the second heating portions to heat simultaneously each of the heating portions.

Thanks to these features, the double-sided flat heater is fully surrounded by the tobacco article so as the heat is substantially fully transferred to the tobacco article without heat wasting or using a large amount of insulators. Additionally, the invention proposes to associate to opposite sides of the heater heating portions which may have different compositions. Thus, it is possible to adapt the response times of these heating portions to obtain a desired effect while vapour generating. Particularly, by “response time”, it should be understood the time that is necessary to the corresponding layer or heating portion to provide the desired effect when it is being heated. The desired effect can be vapour generation. Different response times imply different temperatures of the corresponding layers in each heating portion at least at some moments of the vaping session. These layers can be used to store separately at least a part of the vapour forming agent from the tobacco substrate. By adapting the properties of these layers in each heating portion, their composition and respective arrangement, it is possible to enhance vapour generation at different moments of the vaping session. For example, it is possible to enhance vapour generation at early stages of the vaping session (i.e. preheating stage) or on the contrary, at the end of the vaping session.

According to the invention, the tobacco substrate can present shredded and/or compressed tobacco leafs. The substrate layer comprises such a tobacco substrate together with a bonding material. The substrate layer may thus present a dough flatten and cut in an appropriate manner. In some embodiments, the substrate layer may be free of vapour forming agent. In some other embodiments, the substrate layer comprises one or several vapour forming agents.

According to some embodiments, the agent retainer is chosen in the group consisting of unwoven fabric; cotton and paper.

Thanks to these features, an appropriate agent retainer adapted to retain the vapour forming agent and heat it until a suitable temperature at a suitable moment of the vaping session can be chosen.

According to some embodiments, the vapour forming agent is chosen in the group consisting of:

- polyol such as sorbitol, glycerol;

- glycol such as propylene glycol or triethylene glycol;

- non-polyol such as monohydric alcohols;

- acid such as lactic acid, glycerol derivatives;

- esters such as triacetin, triethylene glycol diacetate, triethyl citrate, glycerine or vegetable glycerine;

- any mixture of the previously cited elements.

Thanks to these features, an appropriate vapour forming agent adapted to release vapour when being heated until a suitable temperature at a suitable moment of the vaping session can be chosen. According to some embodiments, the first heating portion further comprises at least one retainer layer arranged parallel to the substrate layer.

Thanks to these features, a retainer layer in the first heating portion can be used. This retainer layer may have for example a response time different from the response time of the retainer layer used in the second heating portion. Thus, the aerosol generation during the whole vaping session can be adjusted to obtain a desired effect.

According to some embodiments, said retainer layer of the first heating portion is arranged to be heated directly by the corresponding side of the flat heater.

Thanks to these features, the retainer layer of the first heating portion can be heated until a greater temperature than the substrate layer. Thus, in some cases, it is possible to ensure a greater heating temperature of the retainer layer without burning the tobacco substrate contained in the substrate layer.

According to some embodiments, said retainer layer of the first heating portion is arranged to be heated through the corresponding substrate layer.

According to some embodiments, the second heating portion comprises two retainer layers, the substrate layer being arranged between these two retainer layers.

According to some embodiments, said two retainer layers of the second heating portion have different thicknesses and/or comprise different vapour forming agents and/or comprise different agent retainers.

Thanks to these features, it is possible to use two retainer layers having different response times in the same heating portion.

According to some embodiments, the second heating portion further comprises a substrate layer arranged parallel to the retainer layer of this heating portion.

According to some embodiments, said substrate layer of the second heating portion is arranged to be heated directly by the corresponding side of the flat heater. Thanks to these features, it is also possible to use a substrate layer in the second heating portion to improve user experience during a vaping session. Additionally, the different substrate layers can comprise different tobacco substrates (tobacco nature, blend, flavour, etc.).

According to some embodiments, the second heating portion has the same layer composition as the first heating portion.

Thanks to these features, the tobacco article can have a symmetrical structure. Therefore, the flat-shaped heater can be received in the centre of this structure and ensure homogeneous heat transfer over all of the layers.

According to some embodiments, the second heating portion has a layer composition different from a layer composition of the first heating portion.

According to some embodiments, each heating portion is wrapped into a separate wrapper.

Thanks to these features, the flat-shaped heater can be easily inserted in the tobacco article and extracted therefrom.

According to some embodiments, comprising attaching means for attaching said heating portions or their extensions, one to the other.

Thanks to these features, the tobacco article can present a unique piece which can be easily manipulated by the user.

According to some embodiments, each heating portion is extended by a filter part, preferably both heating portions share a same portion of a mouthpiece part.

Thanks to these features, the aerosol generated in each heating portion can be filtered and advantageously cooled before reaching the user’s mouth and/or lips.

According to some embodiments, the or at least one substrate layer and/or the or at least one retainer layer is (are) arranged to be heated directly by the corresponding side of the flat heater. Thanks to these features, the heat transfer can be further improved.

The invention also relates to an aerosol generating assembly comprising:

- an aerosol generating device comprising a double-sided flat heater;

- a flat-shaped tobacco article intended to be heated by the heater to generate aerosol, as defined above.

BRIEF DESCRIPTION OF THE DRAWINGS

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

- Figure 1 is a perspective view of an aerosol generating assembly according to the invention, the aerosol generating assembly comprising an aerosol generating device and a flat-shaped tobacco article;

- Figure 2 is a perspective view of the flat-shaped tobacco article of Figure 1 ;

- Figure 3 is a perspective view of a heating chamber of the aerosol generating device of Figure 1 , the heating chamber receiving the flat-shaped tobacco article;

- Figure 4 is a cross-sectional view of Figure 2 according to plane IV; and

- Figure 5 is a cross-sectional view of a heater part of the flat-shaped tobacco article according to an example different from the example 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 a vapour forming agent. Tobacco may take the form of various materials such as shredded tobacco, granulated tobacco, tobacco leaf and/or reconstituted tobacco. The vaporizable material may also comprise at least one of a gelling agent, a binding agent, a stabilizing agent, and a humectant.

As used herein, the term “vapour forming agent” or “aerosol forming agent” or “aerosol former” may referrer to: 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. A vapour forming agent may also refer to any mixture of the previously cited elements. Figure 1 shows an aerosol generating assembly 10 comprising an aerosol generating device 11 and flat-shaped tobacco article 12 inserted into the aerosol generating device 11 . This flat-shaped tobacco article 12 is shown in more detail on Figure 2.

In reference to Figure 2, the flat-shaped tobacco article 12, referenced here-below as tobacco article 12, is for example a flat-shaped cuboid extending along a longitudinal axis X and having external dimensions LxWxD. In a typical example, the length L of the article according to the longitudinal axis X equals substantially to 33 mm while its width W and depth D are substantially equal respectively to 12 mm and 3,5 mm. According to different examples, the values L, W and D can be selected within a range of +/- 40%, but dimensions of the flat-shaped tobacco article of the invention are not limited to specific ranges. The depth D of the tobacco article 12 is formed by a pair of parallel walls 13A, 13B, called hereinafter article lateral walls 13A, 13B, and the width W of the tobacco article 12 is formed by a pair of parallel walls 14A, 14B, called hereinafter article contact walls 14A, 14B. The article walls 13A, 13B, 14A, 14B form two parallel pairs of outer surfaces of the tobacco article 12. According to other examples of the invention, the tobacco article 12 can have any other suitable flat shape and/or external dimensions. In a general case, the flat shape of the tobacco article should be understood as a shape having its depth for example at least 5 times, advantageously at least 10 times and more advantageously at least 15 times less than each of its longitudinal and/or transversal dimension. Additionally, as it will be explained in further detail below, the depth D of at least a part of the tobacco article 12 may vary when it is received in the aerosol generating device 11 .

The tobacco article 12 comprises a heater part 15 and a mouthpiece part 16 arranged along the longitudinal axis X. In some embodiments, the tobacco article 12 may comprise only the heater part 15. The heater part 15 may for example be slightly longer than the mouthpiece part 16. For example, the length L2 of the heater part 15 according to the longitudinal axis X may be substantially equal to 18 mm and the length L1 of the mouthpiece part 16 according to the longitudinal axis X may be substantially equal to 15 mm. The heater part 15 defines an abutting end 18 of the article 12 and the mouthpiece part 16 defines a mouth end 20 of the article 12. The heater part 15 and the mouthpiece part 16 may be fixed one to the other by a unique wrapper extending around the longitudinal axis X or using different wrappers as it will be explained in further detail below. The or each wrapper may, for example, comprise paper and/or non-woven fabric and/or aluminium. The or each wrapper may be porous or air impermeable. The or each wrapper forms a plurality of airflow channels extending inside the article 12 between the abutting end 18 and the mouth end 20.

The heater part 15 is intended to be heated by a heater and comprises at least one substrate layer and at least one retainer layer. These layers will be explained in more detail referring to cross-sectional views of the tobacco article 12 shown on Figures 4 to 5, according to different examples of the invention.

According to the example of Figure 1 , the mouthpiece part 16 is intended to be received inside a mouthpiece of aerosol generating device 11 . According to other examples of the invention, the mouthpiece part 16 forms itself a mouthpiece intended to be in contact with the user’s mouth and/or lips. The mouthpiece part 16 comprises a core 17 acting for example like a filter. The core 17 may for example be a foam, or packed strands or fibres. The core 17 may be formed through an extrusion and/or rolling process into a stable shape. The article may be shaped to provide one or more airflow channels. In the particular example of Figure 2, the mouthpiece part 16 defines a plurality of venting holes 22 arranged for example according to the whole perimeter of the mouthpiece part 16 along two axis perpendicular to the longitudinal axis X. In other words, according to this example, the venting holes 22 are arranged on each wall of the article among the article lateral walls 13A, 13B and the article contact walls 14A, 14B. According to another example, the venting holes 22 are arranged only on the article contact walls 14A, 14B or preferably, only on one of the article contact walls 14A, 14B. In both examples, the venting holes 22 may be aligned perpendicularly to the longitudinal axis X on the or each corresponding wall of the tobacco article 12, and can be spaced by a same distance. The venting holes 22 allow fresh air entering inside the tobacco article 12 to achieve particular vaping/tasting effects.

Referring again to Figure 1 , the aerosol generating device 11 comprises a device body 30 forming at least one side wall 40. The device body 30 comprises a mouthpiece 32 and a housing 34 arranged successively according to axis Y shown on Figure 1 . According to different examples of the invention, the mouthpiece 32 and the housing 34 can form two different pieces or one single piece. Particularly, in case of two different pieces, the mouthpiece 32 is designed to be fixed on or be received in an insertion opening formed at one of the ends of the housing 34.

In each cross section, the housing 34 may for example form a substantially rectangular shape with rounded edges. In this case, the housing 34 with the mouthpiece 32 form at least four side walls 40. According to other examples, the housing 34 can have a round cross-sectional shape. In this case, it can form with the mouthpiece 32 only one side wall 40. The housing 34 can be formed from a single piece or several assembled pieces made of any suitable material like aluminium or plastic. In some embodiments, the material of the housing 34 can be a thermally conductive material. In some other embodiments, it can be a thermally insulating material. In some embodiments, the housing 34 can form on the corresponding part of the device side wall 40 one or several openings suitable for arranging control and/or visual elements. For example, such element may comprise control buttons, touch panels, screens, LEDs, etc. Particularly, in the example of Figure 1 , the housing 34 forms a slot opening 42 receiving for example a LED indicating at least an ON state of the device 11 . It can also indicate for example a battery law state, an error state, etc.

In some examples, the housing 34 and/or the mouthpiece 32 may form an air inlet 43 in a fluid communication with an airflow path inside the device 11 . This air inlet 43 can be formed for example on the side wall 40, for example in the transition zone between the mouthpiece 32 and the housing 34, as it is shown on Figure 1. According to another example, the air inlet can be formed in a bottom wall of the housing 34, opposite to the insertion opening of the housing 34.

The mouthpiece 32 forms an air outlet 44 in a fluid communication with the airflow path inside the device 11 . Particularly, the air outlet 44 is configured to deliver to the user aerosol formed inside the device 11 . In some examples, the air outlet 44 may also be used to load the tobacco article 12 inside the device 11. In some other examples, the tobacco article 12 can be loaded inside the device 11 when the mouthpiece 32 is detached from the housing 34.

The housing 34 delimits an internal space of the device 11 receiving various elements designed to carry out different functionalities of the device 11. This internal space can for example receive a battery for powering the device 11 , a control module for controlling the operation of the device 11 , a heating chamber 45 for receiving the tobacco article 12 and a heater 47 for heating the heater part 15 of the tobacco article 12. Among these elements, only the heating chamber 45 and the heater 47 will be explained in further detail in reference to Figures 3 and 4. Referring to Figure 3, the heating chamber 45 forms a cup-shaped heating chamber extending along the axis Y between a proximal end 70 and a distal end 71 . The heating chamber 45 is designed to receive the heater part 15 of the tobacco article 12. For this purpose, the heating chamber 45 defines substantially the same cross-sectional shape as the tobacco article 12. Particularly, in the example of the Figure 3, the heating chamber 45 defines a rectangular cross-sectional shape with two parallel chamber lateral walls 73A, 73B and two parallel chamber contact walls 74A, 74B. The heating chamber 45 also defines a distal wall 75 arranged perpendicularly to the axis Y. Particularly, the distal wall 75 is adjacent to each of the walls 73A, 73B, 74A, 74B.

The heating chamber 45 is adapted to receive at least the heater part 15 of the tobacco article 12 so as the longitudinal axis X coincides with the axis Y, the article lateral walls 13A, 13B face the respective chamber lateral walls 73A, 73B and the article contact walls 14A, 14B face the respective camber contact walls 74A, 74B.

According to different examples of the invention, the distal end 71 of the heating chamber 45 may be sealed or may define at least one opening. In the first case, the proximal end 70 of the chamber 45 may form the unique opening of the chamber 45 configured to receive the tobacco article 12 with a play. Particularly, in this case, an airflow channel can be formed between each pair of the lateral walls 13A, 73A and 13B, 73B of the article 12 and the chamber 45, while the corresponding contact walls 14A, 74A and 14B, 74B can be in contact one with the other. As it is shown on Figure 3, while using the device 11 , in this case, an airflow path can extend from the air inlet 43 through the airflow channels formed between the corresponding pairs of lateral walls and then, after a “U”-turn inside the heating chamber 45 through the tobacco article 12 until the air outlet 44. In the second case, all of the walls of the tobacco article 12 can be in contact with the corresponding walls of the heating chamber 45. In this case, while using the device 11 , an airflow path can extend from the air inlet 43 through the opening formed in the distal end 71 and then, through the tobacco article 12 until the air outlet 44. According to other examples, the heating chamber 45 may form other openings for example in its lateral or contact walls to form an airflow path through the tobacco article 12.

As shown on Figure 4, the heater 47 is arranged inside the heating chamber 45 and extends for example from the distal wall 75 substantially along the whole length of the other chamber walls 73A, 73B, 74A, 74B. According to one embodiment of the invention, the heater 47 extends from a centre of the distal wall 75. According to another embodiment, the heater 47 is arranged between the centre of the distal wall 75 and one of the chamber lateral walls 73A, 73B. According to still another embodiment that can be combined with the previous embodiment, the heater 47 is arranged between the centre of the distal wall 75 and one of the chamber contact walls 74A, 74B.

According to the invention, the heater 47 is a double-sided flat heater configured to penetrate inside the heater part 15 of the tobacco article 12 when the article 12 is inserted in the heating chamber 45. Particularly, the heater 47 defines two opposite sides configured to transfer heat to the corresponding portions of the tobacco article 12. For this purpose, the heater 47 may comprise for example a unique heating element, as for example a heating blade. This heating element is connected to the control module of the device 11 and is configured to be operated according to one or several heating profiles by this control module. According to another embodiment, the heater 47 comprises a flat support receiving on each of its sides a heating element. In this case, each heating element can be made for example from a film, like a polyimide film. Additionally, in some embodiments, both heating elements can be operated by the control module according to a same heating profile. According to other embodiments, the heating elements are operated separately by the control module, for example according to different heating profiles. These heating profiles can for example be chosen depending on the tobacco article portion in contact with the corresponding side of the heater 47 and/or depending on the stage of the vaping session (pre-heating, heating, etc.).

In some embodiments, the different sides of the heater 47 can be covered by a same coating or different coatings. In this last case, the coatings can be chosen to ensure different heat transfer properties to obtain for example different heating temperatures on these sides, at least at some stages of the vaping session. These coatings can for example be used when the heater 47 comprises a unique heating element.

Figure 4 shows a cross-sectional view of the tobacco article 12, when it is inserted partially inside the heating chamber 45. According to the example of this Figure 4, the heater part 15 of the tobacco article 12 comprises a first heating portion 81 and a second heating portion 82 intended to be in contact with different sides of the flat heater 47. In other words, the heater part 15 of the tobacco article 12 is configured to receive the heater 47 between its heating portions 81 , 82. In some embodiments, each heating portion 81 , 82 is configured to be compressed at least slightly upon insertion the heater 47 between them. In this case, when non-compressed, the depth D of the tobacco article 12 can correspond substantially to the distance between the chamber contact walls 74A, 74B. Additionally, the heating portions 81 , 82 may have the same thickness or different thicknesses. In the first case, the heater 47 is advantageously arranged at the centre between the chamber contact walls 74A, 74B, and the in the second case, the heater 47 may be arranged in offset with this centre. Additionally, in the second case, the tobacco article 12 may for example define a unique insertion orientation. This insertion orientation can for example be indicated on the external surface of the article 12 or be defined by a specific shape of the article 12 and/or the heating chamber 45 preventing thus the insertion of the tobacco article 12 according to the other orientation.

Each heating portion 81 , 82 can be wrapped in a corresponding wrapper. Additionally, the same wrapper can be used to wrap the corresponding portion of the mouthpiece part 16 of the tobacco article 12. Thus, in the example of Figure 4, a first wrapper 83 can be used to wrap the first heating portion 81 of the heater part 15 and the portion of the mouthpiece part 16 extending continuously the first heating portion 81 to the mouthpiece part 16. Similarly, a second wrapper 84 can be used to wrap the second heating portion 82 of the heater part 15 and the portion of the mouthpiece part 16 extending continuously the second heating portion 82 to the mouthpiece part 16. In this example, the mouthpiece part 16 is thus divided in two distinct portions wrapped in different wrappers 81 , 82. Additionally, in this case, these portions of the mouthpiece part 16 can be attached between them using appropriate attaching means 85, like glue, clips, wires, etc. In a variant, only the first and the second heating portions 81 , 82 are wrapped in different wrappers. In this case, these heating portions 81 , 82 can share the same non-divided portion of the mouthpiece part 16. According to still another variant, the tobacco article 12 has only an external wrapper and the heating portions 81 , 82 can be divided by their layers or any other appropriate mean.

According to the example of Figure 4, the first heating portion 81 comprises a unique layer which is a substrate layer 91. Particularly, the substrate layer 91 comprises tobacco substrate as for example shredded tobacco, granulated tobacco, tobacco leaf and/or reconstituted tobacco. According to some examples, the substrate layer 91 may further comprise a vapour forming agent integrated into the tobacco substrate.

In the same example, the second heating portion 82 also comprises a unique layer. Contrary to the first heating portion, the unique layer of the second heating portion 82 is a retainer layer 92. This retainer layer 92 comprises an agent retainer impregnated with a vapour forming agent. The agent retainer is chosen for example in the group comprising: - unwoven fabric;

- cotton; and

- paper.

The agent retainer can be impregnated with the vapour forming agent in a liquid or gas form using any suitable manufacturing process. For example, this can be done while forming the retainer layer 92. After being impregnated, the agent retainer keeps substantially unchanged its internal structure and stocks the vapour forming agent for example in a form of droplets between different segments of this internal structure.

Advantageously, the retainer layer 92 consists of said agent retainer impregnated with said vapour forming agent. In other words, in this case, the retainer layer 92 comprises only said elements and notably, does not comprise any tobacco or nicotine containing substrate.

Advantageously, in the case where the substrate layer 91 also comprises a vapour forming agent, this vapour forming agent may be chosen different or substantially the same that the vapour forming agent comprised in the retainer layer 92, based on the response time of each layer 91 , 92.

According to the example of Figure 4, each of the layers 91 , 92 is intended to be heated directly by the heater 47. Particularly, as used herein, a layer of the tobacco article 12 is considered to be heated directly by the heater 47 when there is no any other layer of the tobacco article 12 between this layer and the heater 47. However, other elements, like the wrappers 83, 84 or a coating of the heater 47, may be interposed between this layer and the heater 47.

Figure 5 shows an example of the heater portion 15 having a different layer arrangement inside each heating portion 81 , 82.

Particularly, in the example of this Figure 5, the second heating portion 82 comprises two retainer layers 93A, 93C and one substrate layer 93B. The substrate layer 93B is similar to the substrate layer 91 explained above and may for example be arranged between the retainer layers 93A, 93C. Each of the retainer layers 93A, 93C can be similar to the retainer layer 92 explained above. The retainer layers 93A, 93C can comprise a same vapour forming agent and/or agent retainer, or different vapour forming agents and/or agent retainers. Additionally, the retainer layers 93A, 93C can have a same thickness or different thicknesses. In this last case, the retainer layer 93C can be thicker than the retainer layer 93A. Finally, as it is shown on Figure 5, the retainer layer 93C is intended to be heated directly by the corresponding side of the heater 47

The first portion 81 of the heater part 15 can also comprise several layers. Thus, according to the example of the same Figure 5, the first portion 81 comprises one substrate layer 94A and one retainer layer 94B. The substrate layer 94A is for example similar to the substrate layer 93B explained above and is intended for example to be heated directly by the corresponding side of the heater 47. The retainer layer 94B can also be similar to the retainer layers 93A, 93C explained above and may comprise a same vapour forming agent and/or agent retainer, or a vapour forming agent and/or agent retainer different from those of at least one of these retainer layers 93A, 93C. Additionally, the layers 94A, 94B can have the same thickness or different thicknesses. For example, the retainer layer 94B can be thicker than the substrate layer 94A.

Of course, many other examples of layer arrangement inside each of the heating portions 81 , 82 are possible. This arrangement can correspond to any combination of layers explained above. According to some examples, the heating portions 81 , 82 can have the same layer composition. Additionally, for the person skilled in art, it is clear that the number of retainer layers and/or their arrangement and/or their thickness and/or their composition can be adapted basing on the desired response time of each of this layer.

The illustrations in the accompanying Figures 4 and 5 are non-limiting examples of the flat-shaped tobacco article of the invention, and there are numerous modifications and variations of the invention that still fall within the scope of appended claims. For example, the flat-shaped tobacco article 12 in Figure 4 and Figure 5 can have a gap formed between the heating portions 81 , 82, before being inserted into the heating chamber 45. Such a gap can have a shape corresponding to the heater 47, and thus can facilitate insertion of the flat-shaped tobacco article 12 into the heating chamber 45 and/or reduce compression of the heating portions 81 , 82 due to the insertion of the heater 47, for example. Furthermore, unlike the illustrations in Figures 2, 3, 4 and 5, the heating portions 81 , 82 can also be provided as separate members from each other, which are inserted into the heating chamber 45 to come in contact with the opposite sides of the heater 47, respectively.

Claims

1. A flat-shaped tobacco article (12) comprising a first heating portion (81 ) and a second heating portion (82) designed to be arranged parallel to the first heating portion (81 ); the first heating portion (81) comprising a substrate layer (91 ; 94A) comprising tobacco substrate; the second heating portion (82) comprising a retainer layer (92; 93C) comprising a vapour forming agent and an agent retainer retaining the vapour forming agent; the flat-shaped tobacco article (12) being configured to receive at least a part of a double-sided flat heater (47) of an aerosol generating device (11 ) between the first and the second heating portions (81 , 82) to heat simultaneously each of the heating portions (81 , 82), said substrate layer (91 ; 94A) and retainer layer (92; 93C) of respectfully the first heating portion (81) and the second heating portion (82) are arranged to be heated directly by the corresponding side of the flat heater (47).

2. The flat-shaped tobacco article (12) according to claim 1 , wherein the agent retainer is chosen in the group consisting of:

- unwoven fabric;

- cotton;

- paper.

3. The flat-shaped tobacco article (12) according to claim 1 or 2, wherein the vapour forming agent is chosen in the group consisting of:

- polyol such as sorbitol, glycerol;

- glycol such as propylene glycol or triethylene glycol;

- non-polyol such as monohydric alcohols;

- acid such as lactic acid, glycerol derivatives;

- any mixture of the previously cited elements.

4. The flat-shaped tobacco article (12) according to any one of the preceding claims, wherein the first heating portion (81) further comprises at least one retainer layer (94B) arranged parallel to the substrate layer (94A).

5. The flat-shaped tobacco article (12) according to claim 4, wherein said retainer layer (94B) of the first heating portion (81) is arranged to be heated through the corresponding substrate layer (94A).

6. The flat-shaped tobacco article (12) according to any one of the preceding claims, wherein the second heating portion (82) further comprises a substrate layer (93B) arranged parallel to the retainer layer (93C) of this heating portion.

7. The flat-shaped tobacco article (12) according to claim 6, wherein the second heating portion (82) comprises two retainer layers (93A, 93C), the substrate layer (93B) being arranged between these two retainer layers (93A, 93C).

8. The flat-shaped tobacco article (12) according to claim 7, wherein said two retainer layers (93A, 93C) of the second heating portion (82) have different thicknesses and/or comprise different vapour forming agents and/or comprise different agent retainers.

9. The flat-shaped tobacco article (12) according to any one of the preceding claims, wherein the second heating portion (82) has a layer composition different from a layer composition of the first heating portion (81).

10. The flat-shaped tobacco article (12) according to any one of the preceding claims, wherein each heating portion (81 , 82) is wrapped into a separate wrapper (83, 84).

11 . The flat-shaped tobacco article (12) according to any one of the preceding claims, further comprising attaching means (85) for attaching said heating portions or their extensions, one to the other.

12. The flat-shaped tobacco article (12) according to any one of the preceding claims, wherein each heating portion (81 , 82) is extended by a filter part (16), preferably both heating portions (81 , 82) share a same portion of a mouthpiece part (15).

13. An aerosol generating assembly (10) comprising:

- an aerosol generating device (11) comprising a double-sided flat heater (47);

- a flat-shaped tobacco article (12) intended to be heated by the heater (47) to generate aerosol, the flat-shape tobacco article (12) being according to any one of the preceding claims.