FLAT TOBACCO ARTICLES WITH IMPROVED HEAT TRANSFER AND ASSOCIATED AEROSOL GENERATING DEVICES - Patent application

Abstract

The present invention relates to a flat tobacco article (12) configured to operate with an aerosol generating device and extending along an article axis (X). The flat tobacco article (12) includes a first tobacco layer (50A) defining a first layer inner surface (60A) and a first layer outer surface (62A) designed to be heated by a heater (26) of an aerosol generating device, and a non-tobacco core element (52) designed to contact the first layer inner surface (60A) and apply pressure to the inner surface (60A) to push the first layer outer surface (62A) towards the heater.

Description

[Technical field]

[0001] The present invention relates to flat tobacco articles.

[0002] The present invention also relates to an aerosol-generating assembly associated with such a tobacco article.

[0003] The present invention also relates to methods of making such tobacco articles.

[0004] In particular, the aerosol generation assembly comprises an aerosol generation device configured to operate with a flat tobacco article according to the invention, comprising a tobacco substrate capable of forming an aerosol upon heating. Thus, such types of aerosol generation assemblies are also known as heated non-combustion devices, and are adapted to heat, rather than ignite, the substrate by conduction, convection and / or radiation to generate an aerosol for inhalation. [Background technology]

[0005] The popularity and use of reduced-risk or modified-risk devices (also known as vaporizers) has grown rapidly in recent years as an aid to support regular smokers who wish to quit smoking traditional tobacco products such as cigarettes, cigars, cigarillos and roll-up cigarettes. A variety of devices and systems are available that heat or warm a vaporizable substance, as opposed to lighting the tobacco of traditional tobacco products.

[0006] A commonly available device that reduces or modifies the risk is the heated substrate aerosol generating device or heated non-combustion device. This type of device generates an aerosol or vapor by heating an aerosol substrate, typically comprising moist tobacco or other suitable vaporizable material, to a temperature typically ranging from 150°C to 350°C. By heating the aerosol substrate but not burning or igniting it, an aerosol is released that contains the components desired by the user but that are not the toxic and carcinogenic by-products of combustion and ignition. Furthermore, since the aerosol generated by heating tobacco or other vaporizable material does not contain the burnt or bitter taste that typically results from combustion and ignition, which can be unpleasant to the user, the substrate therefore does not require the sugar and other additives that are typically added to such materials to make the smoke and / or vapor more palatable to the user.

[0007] Tobacco articles that can be used with such types of aerosol generating devices can take a variety of forms, some of which can represent elongated sticks or any other suitable shape, such as flattened, but the design of the tobacco article often represents a trade-off between convenience, aesthetics, and efficiency in heating.

[0008] Specifically, flat tobacco articles generally require that the tobacco portion be wrapped in paper to avoid the need for direct contact with the tobacco material, to allow convenient and hygienic handling of the article, and to make the sample more appealing to consumers. However, the paper acts as a thermal barrier during external heating, reducing the potential efficiency of the device. Additionally, such tobacco articles are very thin (e.g., 1 mm), so it is difficult to heat the tobacco article from the inside, as is used in tobacco sticks that use internal susceptors or heated leaves. Summary of the Invention [Problem to be solved by the invention]

[0009] One of the objects of the present invention is to provide a flat tobacco article whose heating efficiency can be increased in a simple manner. [Means for solving the problem]

[0010] To this end, the present invention relates to a flat tobacco article configured to operate with an aerosol generating device and extending along an article axis, the flat tobacco article comprising: a first tobacco layer defining a first layer inner surface and a first layer outer surface designed to be heated by a heater of an aerosol generating device; a non-tobacco core element designed to contact the first layer inner surface and exert pressure on the first layer outer surface to urge the first layer outer surface towards the heater.

[0011] With these features, the tobacco article is designed to ensure that, when inserted into a device, pressure is applied between the tobacco article and the heater of the associated device. The tobacco article is in this way assured of firm and uniform contact with the heater. This contact improves heat transfer through the joint and ensures consistent aerosol generation from the tobacco layer, regardless of thickness variations due to manufacturing processes.

[0012] According to some embodiments, the non-tobacco core elements include discontinuous surface portions in contact with the first layer inner surface and voids extending between the surface portions such that the core elements can be elastically deformed when a compressive force is applied to the layer in a direction perpendicular to the first layer outer surface such that the non-tobacco core elements are designed to apply pressure to the first layer outer surface to force this inner surface outwardly.

[0013] These features allow the core element to be compressed and exert pressure on the tobacco layer to ensure good contact with the heater, while allowing air flow across the article through the voids.

[0014] According to some embodiments, the article further includes a second tobacco layer defining a second layer inner surface and a second layer outer surface designed to be heated by a heater of an aerosol generating device, and the core element is disposed between the first and second tobacco layers and includes a second discontinuous surface portion for further contacting the second layer inner surface, and a void extending between the second surface portions such that the core element can be elastically deformed when a compressive force is applied to the second layer in a direction perpendicular to the second layer outer surface such that the non-tobacco core elements are designed to apply pressure to the second layer inner surface to push the second layer outer surface outward.

[0015] With these features, aerosol generation is carried out between the two tobacco layers, and the single core element can ensure tight contact between each tobacco layer and the associated heater.

[0016] According to some embodiments, the core element includes one or more air flow channels extending along the article axis.

[0017] These features allow airflow to flow through the tobacco article in the airflow channel and mix with the generated tobacco aerosol obtained through heating of the tobacco layer by the respective heater. This vapor is delivered to the user for inhalation.

[0018] According to some embodiments, the core element extends along the entire length of the or each tobacco layer.

[0019] These features ensure that the core element ensures firm and uniform contact of all tobacco layers with their associated heaters.

[0020] According to some embodiments, the tobacco article extends along an article axis between a mouth end and an abutment end, the tobacco article including a mouthpiece portion adjacent the mouth end and a tobacco portion adjacent the abutment end, and the tobacco layer and non-tobacco core elements are disposed within the tobacco portion.

[0021] With these features, the article includes a tobacco portion designed for insertion into the heating chamber of the device, and a mouthpiece portion designed for insertion into the mouthpiece.

[0022] According to some embodiments, the core element comprises a plurality, advantageously at least three, distinct corrugations in contact with the or each layer inner surface, the corrugations advantageously extending longitudinally along the article axis.

[0023] These features allow the corrugations to be compressed and exert pressure on the tobacco layer to ensure good contact with the heater while allowing air flow across the article. The corrugations allow for stable behavior of the article under compression.

[0024] According to some embodiments, the core element is a resilient element configured to exert pressure when compressed, the core element being conveniently made from paper.

[0025] According to some embodiments, the tobacco article further comprises a wrapper which assembles the or each tobacco layer together with the core element, the core element and the wrapper being conveniently made from a single sheet.

[0026] With these features, manufacturing of the article is simple as it requires only one sheet of paper to obtain the core element and the wrapper.

[0027] According to some embodiments, the core element includes a moisture resistant coating.

[0028] With these features, the coating prevents excessive softening of the core element and loss of aerosol delivery due to the paper core that comprises the core element.

[0029] According to some embodiments, the flat tobacco represents the article thickness in a cross section perpendicular to the article axis and the core element represents the core thickness in a cross section perpendicular to the article axis, the ratio between the core thickness and the article thickness being comprised between 0.2 and 0.8.

[0030] According to some embodiments, the core element is a thermal expansion element configured to expand while being heated.

[0031] In one possible mode, the present invention relates to a flat tobacco article configured to operate with an aerosol generating device and extending along an article axis, the flat tobacco article comprising: a first tobacco layer defining a first layer inner surface and a first layer outer surface designed to be heated by a heater of an aerosol generating device; a non-tobacco core element including a body made of a deformable, heat-expandable material in contact with the first layer inner surface and designed such that when the core element is heated, the non-tobacco core element exerts pressure on said inner surface to push the first layer outer surface outward; Includes.

[0032] The tobacco article may further include a second tobacco layer defining a second layer inner surface and a second layer outer surface designed to be heated by a heater of the aerosol generating device; the core element is disposed between the first tobacco layer and the second tobacco layer and further contacted with an inner surface of the second layer; The deformable, thermally expandable body of the core element is designed to exert pressure on the second layer inner surface to urge the second layer outer surface outward when the core element is heated.

[0033] Due to these characteristics, the core element may be formed from a foam or material with a lattice structure and / or a positive coefficient of thermal expansion that, upon heating, increases the pressure between the tobacco layer and the associated heater.

[0034] The present invention provides an aerosol generation assembly comprising: a flat tobacco article as defined above; an aerosol generation device extending along a device axis and including a heating chamber between a closed end and an opening, the heating chamber including at least one heater; The invention also relates to an aerosol generation assembly, wherein the heating chamber is configured to receive a flat tobacco article through its opening, and the first layer outer surface faces one of the or each of the heaters.

[0035] According to some embodiments, the flat tobacco article can be transformed from a released configuration to a compressed configuration in which the core is compressed and exerts pressure on the inner surface, and the flat tobacco article is in the compressed configuration when inserted into a heating chamber.

[0036] According to some embodiments, the flat tobacco represents a cross section perpendicular to the article axis representing an article width and an article thickness, and the opening of the heating chamber represents a chamber width and a chamber height, the chamber height being less than the article thickness in the released configuration.

[0037] The present invention also relates to a method for producing such a flat tobacco article, the method comprising the steps of: providing a layer of elastic elements, advantageously a layer of paper; forming a compressible three-dimensional core element from a layer of elastic material, the core having a thickness and a flattened shape with first and second opposed larger sides; attaching a tobacco layer to a first side of the core element; Includes.

[0038] Preferably, the method further comprises attaching a second tobacco layer to a second side of the core element, for example to form a sandwich structure.

[0039] In the method, forming the core element may include forming a corrugated layer. In particular, the layer may be corrugated by a forming roll.

[0040] The method may include placing at least a tobacco layer on top of the core element, and bending and adhering the remainder of the layer around the tobacco layer.

[0041] The method may further include cutting the layers of the sandwich into individual flat articles.

[0042] The invention and its advantages will be better understood on reading the following description, given by way of non-limiting example only, and with reference to the accompanying drawings, in which: [Brief description of the drawings]

[0043] [Figure 1] FIG. 1 is a perspective view of an aerosol generation assembly according to the present invention, the aerosol generation assembly comprising an aerosol generating device according to the present invention and a flat tobacco article, the flat tobacco article being usable with the aerosol generating device; [Diagram 2] FIG. 2 is a perspective view of the flat tobacco article of FIG. 1. [Diagram 3] 3A-3C are cross-sectional views of the flat tobacco article of FIG. 2 in a released configuration and a compressed configuration. [Figure 4] FIG. 2 is a transverse cross-sectional view of the aerosol generation assembly of FIG. 1. [Diagram 5] FIG. 2 is a perspective view of the aerosol generation assembly of FIG. 1 without the mouthpiece. [Figure 6] 3A-3D sequentially depict a method for producing the flat tobacco article of FIG. 2. [Figure 7] 1A-1D are perspective views of different variations of core elements of flat tobacco articles. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0044] Before the present invention is described, it is to be understood that it is not limited to the details of construction set forth in the following description, as it will be apparent to one skilled in the art having the benefit of this disclosure that the invention is capable of other embodiments and of being practiced or carried out in various ways.

[0045] As used herein, the term "aerosol generating device" or "device" may include an inhalation device for delivering aerosol to a user, including aerosol for inhalation, using a heater element, which will be described in further detail below. The device may be portable. "Portable" may refer to a device for use when held by a user. The device may be adapted to generate a variable amount of aerosol, for example by activating a heater element for various amounts of time (as opposed to a fixed amount of aerosol), which may be controlled by a trigger. The trigger may be an inhale button and / or a draw sensor, etc., that the user activates. The draw sensor may be sensitive to the duration of the draw as well as the intensity of the draw, to provide a variable amount of vapor (to mimic the smoking effect of a conventional combustion-based smoking article, such as a cigarette, cigar, or pipe, etc.). The device may include a temperature regulation control device to drive the temperature of the heater and / or heated aerosol-generating material (aerosol precursor) to a specific target temperature and then maintain the temperature at the target temperature at which aerosol can be efficiently generated.

[0046] As used herein, the term "aerosol" may include a suspension of vaporizable material as one or more of solid particles, liquid droplets, or gas. The suspension may be in a gas, including air. Aerosol may generally refer to / include vapors herein. Aerosol may include one or more components of vaporizable material.

[0047] As used herein, the term "vaporizable material" or "precursor" may refer to a smokable material, which may include, for example, nicotine or tobacco and an aerosol-forming agent. Tobacco may take the form of various materials, such as cut tobacco, granulated tobacco, tobacco leaf, and / or reconstituted tobacco. Suitable aerosol-forming agents include polyols, such as sorbitol, glycerol, and glycols, such as propylene glycol or triethylene glycol, non-polyols, 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 include at least one of a gelling agent, a binder, a stabilizer, and a humectant.

[0048] Description of the main embodiments of the invention 1 shows an aerosol-generating assembly 10, including an aerosol-generating device 11 and a flat tobacco article 12 (hereafter referred to as tobacco article 12). The flat tobacco article 12 is specifically of planar shape, meaning that its effective thickness is much smaller than its other dimensions. The aerosol-generating device 11 is intended to work with the tobacco article 12, which is shown in more detail in FIG. 2.

[0049] The aerosol generating device 11 comprises a device body extending along a device axis Y. The device body comprises a mouthpiece 13 and a housing 14 arranged successively along the device axis Y. According to the example of FIG. 1, the mouthpiece 13 and the housing 14 form two distinct pieces. In particular, the mouthpiece 13 is here designed to be fixed on or received in an insertion opening formed at one of the ends of the housing 14. In this case, the tobacco article 12 can be inserted inside the device 11 once the mouthpiece 13 has been removed from the housing 14. According to another example (not shown), the mouthpiece 13 and the housing 14 form one unique piece. In this case, the tobacco article 12 can be inserted inside the device 11, for example through a flow outlet. According to both examples, the mouthpiece 13 defines a through hole adapted to receive at least a part of the tobacco article 12.

[0050] The housing 14 defines an interior space of the device 11 that receives various elements designed to perform different functions of the device 11. This interior space may receive, for example, a battery for powering the device 11, a control module for controlling the operation of the device 11, a heating chamber 20 for heating the tobacco article 12, etc. The housing may further include airflow paths and / or inlets for introducing air into the tobacco article. Of these elements, only the heating chamber 20 will be described in more detail with reference to Figures 4 and 5.

[0051] 4 and 5, the heating chamber 20 may form a cup shape adapted to receive at least a portion of the tobacco article 12. The heating chamber 20 may form a rectangular parallelepiped shape extending along the device axis Y that complements the shape of the tobacco article 12.

[0052] The heating chamber 20 includes a pair of parallel narrow walls 22A, 22B extending along the device axis Y, a pair of parallel wide walls 23A, 23B also extending along the device axis Y, and a bottom wall adjacent each of said walls and extending perpendicular to the device axis Y. The bottom wall thus forms a closed end 24 of the chamber 20. Opposite the closed end 24, the heating chamber 20 defines an opening 25 configured to receive the tobacco article 12. The opening 25 of the heating chamber 20 defines a chamber width Wc and a chamber height Dc.

[0053] With reference to FIG. 5, the device 11 includes at least one heater 26. Here, the device 11 includes two heaters 26. Each heater 26 may be arranged in contact with one of the outer surfaces of the narrow walls 22A, 22B of the heating chamber 20. Each heater 25 may include a polyimide film heater extending along substantially the total area of ​​said outer surface of the narrow walls 22A, 22B of the chamber, or along only a portion of this surface. In this last case, said portion may form a width substantially equal to the width W of the aerosol-generating substrate 12. Each heater 26 is powered by a battery and controlled by a control module of the aerosol-generating device 11. In some embodiments, the aerosol-generating device 11 may include a single heater 26 mounted on one of the outer surfaces of one of the narrow walls 22A, 22B of the chamber. The narrow walls are preferably made of a thin conductive material, preferably a metal such as stainless steel.

[0054] With reference to FIG. 2, the tobacco article 12 is, for example, a flattened rectangular parallelepiped extending along the article axis X and having external dimensions La×Wa×Da. In a specific example, the length La of the article 12 according to the article axis X is substantially equal to 33 mm, while its width Wa and thickness Da are substantially equal to 12 mm and 4 mm, respectively. According to different examples, the values ​​La, Wa and Da can be selected, for example, within a range of + / - 40%. The thickness Da of the tobacco article 12 is formed by a pair of parallel walls 30A, 30B (hereinafter referred to as narrow walls 30A, 30B), and the width W of the substrate is formed by a pair of parallel walls 32A, 32B (hereinafter referred to as wide walls 32A, 32B). In some embodiments, the edges between the wide walls 32A, 32B and the narrow walls 30A, 30B may be rounded. According to other embodiments of the present invention, the tobacco article 12 may have any other suitable flat shape and / or outer dimensions.

[0055] When inserted into the heating chamber 20, the tobacco article 12 remains in a flattened shape.

[0056] The tobacco article 12 comprises a tobacco section 40 and a mouthpiece section 42 arranged along an article axis X. The tobacco section 40 may, for example, be slightly longer than the mouthpiece section 42. For example, the length of the tobacco section 40 along the article axis X may be substantially equal to 18 mm, and the length of the mouthpiece section 16 along the article axis X may be substantially equal to 15 mm. The tobacco section 40 defines an abutment end 44 of the article 12, and the mouthpiece section 42 defines a mouth end 46 of the article 12. The tobacco section 40 and the mouthpiece section 42 may be secured one to the other by a wrapper 48 extending around the article axis X.

[0057] The wrapper 48 forms the narrow and broad walls 30A, 30B, 32A, 32B of the tobacco article 12. The wrapper 48 may be formed from the same wrapping sheet. The wrapper 48 may comprise, for example, paper and / or a nonwoven fabric and / or aluminum foil. The wrapper 48 may be porous or air impermeable and forms a plurality of air flow channels that extend inside the article 12 between the abutment end 44 and the mouth end 46. As described below, the wrapper 48 and the core elements disposed within the tobacco section 40 are conveniently made from a single sheet, specifically a piece of paper.

[0058] When the tobacco article 12 is inserted into the heating chamber 20, the corresponding broad walls 32A, 32B of the tobacco article 12 face the corresponding broad walls 23A, 23B of the heating chamber 20, the corresponding narrow walls 30A, 30B of the tobacco article 12 face the corresponding narrow walls 22A, 22B of the heating chamber 20, and the abutting end 44 of the tobacco article 12 abuts the bottom wall defining the closed end 24. Specifically, the heating chamber 20 is configured to receive the tobacco article 12 such that the narrow walls 30A (respectively 30B) of the tobacco article 12 face the narrow walls 22B (respectively 22A) of the heating chamber 20, and the broad walls 23A (respectively 23B) of the tobacco article 12 face the broad walls 32B (respectively 32A) of the heating chamber 20.

[0059] The mouthpiece portion 42 forms a cooling and / or filtering portion. The mouthpiece portion 42 is intended to act as a cooler and / or filter, for example to slightly cool the vapour and / or filter it before it is inhaled by the user, as represented by arrow F in Figures 1 and 2. The mouthpiece portion may contain filtering materials such as paper and / or cellulose acetate fibres.

[0060] The tobacco section 40 is intended to be heated by a heater 26, seen in Figure 5, as will be explained in more detail below. As shown in Figure 2, the tobacco section 40 comprises at least a tobacco layer 50 and a non-tobacco core element 52. In particular, the tobacco section 40 comprises a first tobacco layer 50A and a second tobacco layer 50B. The core element 12 exhibits a core thickness De in a cross section perpendicular to the article axis X. The ratio between the core thickness De and the article thickness Da is comprised between 0.2 and 0.8.

[0061] Each tobacco layer 50 includes a vaporizable material as defined above. Each tobacco layer 50 extends inside the tobacco section 40 along the article axis X. The first tobacco layer 50A and the second tobacco layer 50B form two opposing sides of the tobacco section 40. Each tobacco layer 50 contacts the wrapper 48. Specifically, the first tobacco layer 50A contacts the broad wall 32A and the second tobacco layer 50B contacts the other broad wall 32B. The two tobacco layers 50 form a gap between them, in which the core element 52 is disposed.

[0062] 3, the first tobacco layer 50A defines a first layer inner surface 60A and a first layer outer surface 62A. The first layer inner surface 60A is designed to contact the core element 52. The first layer outer surface 62A is designed to be heated by an associated heater 26 of the device 11. The second tobacco layer 50B defines a second layer inner surface 60B and a second layer outer surface 62B. The second layer inner surface 60B is designed to contact the core element 52. The second layer outer surface 60B, designed to be heated by an associated heater 26, is different from the heater 26 associated with the first layer 50A.

[0063] The non-tobacco core element 52 contacts the first layer inner surface 60A and advantageously the second layer inner surface 60B. It should be understood that the core element 52 does not include any vaporizable material. Referring to FIG. 3, the tobacco article 12 can be switched from a released configuration depicted in part A of FIG. 3 to a compressed configuration depicted in part B of FIG. 3. In the released configuration, no external force is applied to the tobacco article 12. In the compressed configuration, the core element 52 is compressed. Specifically, the core element 52 is compressed on a compression axis Z perpendicular to the article axis X. In the compressed configuration, the core element 52 applies pressure to the inner surfaces 60A, 60B of the tobacco layers 50A, 50B in response to this compression. The tobacco article 12 is in the compressed configuration when inserted into the heating chamber 20. Specifically, the chamber height Hc is less than the article thickness Ha in the released configuration. The tobacco article 12 is thus compressed for insertion into the heating chamber 20 through the opening 25. Upon insertion, the core element 52 exerts pressure on the inner surface 60A to urge the first layer outer surface 60A towards the associated heater 26. Similarly, the core element 52 is designed to exert pressure on the inner surface 60B to urge the second layer outer surface 60B towards the associated heater 26. Thus, the core element 52 ensures uniform and efficient heat transfer between each heater 26 and the associated tobacco layer 50A, 50B by increasing the contact pressure, thereby reducing associated contact losses. Specifically, the core element 52 prevents the formation of any voids between the heater 26 and the tobacco layers 50A, 50B that could impair the heating function.

[0064] 3, the core element 52 includes a first discontinuous surface portion 64A in contact with the first layer inner surface 60A. The core element 52 advantageously includes a second discontinuous surface portion 64B in contact with the second layer inner surface 60B, where each discontinuous surface portion 64 is a line extending along the article axis X.

[0065] The core elements 52 further include voids 66 extending between the surface portions 64 to render the core elements 52 elastically deformable when a compressive force is applied to the layers 50A, 50B in a direction perpendicular to the associated layer outer surfaces 62A, 62B such that the non-tobacco core elements 52 are designed to apply pressure to the inner surfaces 60A, 60B to urge the layer outer surfaces 62A, 62B outwardly.

[0066] The core element 52 is an elastic element configured to exert a pressure when compressed. The core element 52 is advantageously made from paper. The core element 52 extends along the entire length of each tobacco layer 50A, 50B along the article axis X. The core element 52 advantageously extends along the entire width of each tobacco layer 50A, 50B perpendicular to the article axis X. With reference to figures 2 to 4, the core element 52 is here a corrugated sheet. The core element 52 comprises a plurality of distinct corrugations 65 in contact with each layer inner surface 60A, 60B. Advantageously, the core element 52 comprises at least three corrugations 65 that ensure a stable behavior under compression. The corrugations 65 extend here longitudinally along the article axis X. The corrugations 65 form waves that can be compressed under pressure. The corrugated sheet advantageously presents a thickness comprised between 80 μm and 300 μm.

[0067] Core element 52 may include a moisture resistant coating that prevents excessive softening of core element 52 and loss of vapor delivery due to the paper core that comprises core element 52 while the assembly 10 is being used by a consumer.

[0068] Core element 52 includes one or more air flow channels that extend along article axis X. As can be seen in FIG. 2, the air flow channels are formed by voids 66 disposed between surface portions 64 to allow vapor flow F to proceed through article 12.

[0069] Operation of the invention The operation of the aerosol generating assembly 10 will now be described. First, the tobacco article 12 is considered to be extracted from the device 11. To insert it, the user first removes the mouthpiece 13 from the housing 14. The tobacco article 12 is then in the released configuration.

[0070] The user then compresses the tobacco article 12 as depicted in Figure 3. Once the tobacco article 12 is in the compressed configuration, the user inserts the tobacco portion 40 of the article 12 into the heating chamber 20. In a convenient variation, the tobacco article 12 is compressed upon insertion into the heating chamber 20 by a guide channel piece. In another convenient variation, a mechanism is disposed within the heating chamber 20 that compresses the tobacco article 12 once it is fully inserted.

[0071] The user then secures the mouthpiece 13 onto the housing 14 by sliding the mouthpiece portion 42 of the tobacco article 12 inside the mouthpiece 13 .

[0072] The user may then activate operation of the aerosol generation assembly 10, for example by actuating an on button or by puffing, which generates an airflow in an airflow path formed inside the device 11 between a flow inlet and a flow outlet within the device 11.

[0073] The flow inlet may be located near the mouthpiece 13, with the airflow passing between the broad walls 23A, 23B of the heating chamber 20 and the article 12. The transition is located at the closed end 24 of the heating chamber 20, which forms a "U" turn inside the heating chamber 20. The transition allows the airflow F to flow inside the tobacco article 12, as shown in FIG.

[0074] In a variant, the flow inlet may be located on the opposite side of the mouthpiece 13, with the airflow F passing directly across the device 11 and the article 12 without making a U-turn.

[0075] Airflow F passes through the tobacco article 12 and flows in the airflow channels formed by the gaps 66 between the corrugations 65. The air mixes with the tobacco aerosol obtained through heating of the tobacco layers 50A, 50B by the respective heaters 26. If the article 12 includes ventilation holes, the flow toward the mouthpiece may further include fresh air that has entered through these holes.

[0076] Finally, the vapor containing the tobacco aerosol is delivered to the user through the mouthpiece 13, as shown in FIG.

[0077] Manufacture of tobacco articles We now describe the manufacture of the flat tobacco article 12. The different steps of the method for manufacturing the tobacco article 12 are represented in FIG.

[0078] With reference to this figure, the method comprises in a first step (A) providing a layer of elastic element, advantageously a layer of paper.

[0079] In step (B), the method includes forming a compressible three-dimensional core element 52 from a layer of resilient material. Core element 52 has a flattened shape with a thickness and first and second opposing larger sides.

[0080] Specifically, the core element 52 is obtained by a roll that forms part of the layer.

[0081] In step (C), the tobacco layer 50A is attached to a first side of the core element 52 to form a discontinuous surface portion 64A.

[0082] The method further includes attaching a second tobacco layer 50B to a second side of the core element 52, advantageously to form the second discontinuous surface portion 64B. The steps of attaching the tobacco layers 50A, 50B to the core element may occur simultaneously or sequentially.

[0083] Specifically, tobacco layers 50A, 50B are placed on either side of a core element 52 to form a sandwich structure.

[0084] In step (D), the remainder of the paper layer is wrapped around the tobacco layers 50A, 50B to form the wrapper 48. Specifically, the remainder of the paper layer is bent and glued around the tobacco layers 50A, 50B at the tobacco article sides 30A and 30B. The core element 52 and the wrapper 48 of the article 12 are made from the same paper sheet, which is now folded around the tobacco layers 50A, 50B. Specifically, a first portion of the paper layer is folded over the outer surface of the top tobacco layer 50A and a second, opposite portion of the paper layer is folded over the outer surface of the bottom tobacco layer 50B. The outer surfaces of the tobacco layers are advantageously completely covered by the respective portions of the paper layer.

[0085] The method may include the optional step of adding additions to the cooling section 42, such as filters or other structures, contiguous to the article axis X from the tobacco layers 50A, 50B of the same width and thickness.

[0086] The method includes an optional final step of cutting the core elements and wrappers into single pieces to obtain a plurality of tobacco articles 12.

[0087] Description of Other Embodiments of the Invention FIG. 7 shows different variations of the core element 52 .

[0088] In part (A), each corrugation 65 represents a triangular transverse cross section. Each corrugation 65 is then a right prism with a triangular base extending along the article axis X. There are voids between the corrugations.

[0089] The article 12 includes first discontinuous surface portions 64A, here in the form of parallel lines extending along the article axis X. Second discontinuities, also in the form of parallel lines extending along the article axis X, may be formed at the junctions between the rectangular posts. Each of the first and second discontinuous surface portions may be attached to the tobacco layer to form channels between the tobacco layer and the voids.

[0090] In part (B), each corrugation 65 presents a trapezoidal transverse cross section. Each corrugation 65 is then a right prism with a trapezoidal base extending along the article axis X. Between the corrugations there are voids in the form of parallel channels.

[0091] Article 12 includes only first discontinuous surface portions 64A, here in the form of parallel stripes extending along article axis X.

[0092] In part (C), each corrugation 65 is a cylinder disposed between two tobacco layers 50A and 50B. The corrugations are spaced both longitudinally and laterally to form voids between the corrugations.

[0093] Article 12 includes a first discontinuous surface portion 64A and a second discontinuous surface portion 64B, here in the shape of a disk.

[0094] In part (D), each corrugation 65 is a paraboloid. The core element 52 then represents the shape of an egg crate.

[0095] Article 12 includes first discontinuous surface portions 64A and second discontinuous surface portions 64B, here in the form of dots.

[0096] For example, waveform 65 may be obtained by additive manufacturing.

[0097] In another embodiment, the corrugations 65 extend transversely perpendicular to the article axis X.

[0098] In another embodiment, the core element 52 is a thermal expansion element configured to expand while being heated. Specifically, the core element 52 is a foam or material with a high efficient coefficient of thermal expansion such that, upon heating, the pressure between the tobacco article 12 and the respective heater 26 increases. In this case, no compression of the tobacco article 12 is required when inserting it. Expansion occurs upon heating the thermal expansion material.

[0099] It will be apparent to one skilled in the art that the above embodiments may be combined to produce other embodiments in various ways.

Claims

**Claim 1** A flat tobacco article (12) configured to operate with an aerosol generating device (11) and extending along an article axis (X), comprising a first tobacco layer (50A) defining a first layer inner surface (60A) and a first layer outer surface (62A), designed to be heated by a heater (26) of the aerosol generating device (11); and a non-tobacco core element (52) in contact with the first layer inner surface (60A) and designed to apply pressure to this inner surface (60A) to push the first layer outer surface (62A) towards the heater (26). The non-tobacco core element (52) has a discontinuous surface portion in contact with the first layer inner surface (60A), and an air gap extending between the surface portions such that the core element can be elastically deformed when a compressive force is applied to the layer (50A) in a direction orthogonal to the first layer outer surface (62A) so that the non-tobacco core element is designed to apply pressure to this inner surface (60A) to push the first layer outer surface (62A) outwards. A flat tobacco article (12). **Claim 2** Further comprising a second tobacco layer (50B) defining a second layer inner surface (60B) and a second layer outer surface (62B), designed to be heated by a heater (26) of the aerosol generating device (11); The core element (52) is disposed between the first tobacco layer (50A) and the second tobacco layer (50B), has a second discontinuous surface portion in further contact with the second layer inner surface (60B), and an air gap extending between the second surface portions such that the core element can be elastically deformed when a compressive force is applied to the second layer (50B) in a direction orthogonal to the second layer outer surface (62B) so that the non-tobacco core element is designed to apply pressure to the second layer inner surface (60B) to push the second layer outer surface (62B) outwards. The flat tobacco article (12) according to claim 1. **Claim 3** The flat tobacco article (12) according to claim 1, wherein the gap forms one or more airflow channels extending along the article axis (X). **Claim 4** The flat tobacco article (12) according to claim 1, wherein the core element (52) extends along the entire length of the tobacco layer or each tobacco layer (50A, 50B). **Claim 5** The tobacco article (12) extends along the article axis (X) between a mouth end portion (46) and a contact end portion (44), and the tobacco article (12) includes a mouthpiece portion (42) adjacent to the mouth end portion (46) and a tobacco portion (40) adjacent to the contact end portion (44). The tobacco layers (50A, 50B) and the non-tobacco core element (52) are disposed within the tobacco portion (40) of the flat tobacco article (12) according to claim 1.

6. The core element (52) includes a plurality of, preferably at least three, distinct corrugations (65) that contact the inner surface (60A, 60B) of the or each layer. The corrugations (65) preferably extend longitudinally along the article axis (X) of the flat tobacco article (12) according to claim 1.

7. The core element (52) is an elastic element configured to apply pressure when compressed. The core element is preferably made of paper in the flat tobacco article (12) according to claim 1.

8. The flat tobacco article further includes a wrapper (48) that assembles the or each tobacco layer (50A, 50B) together with the core element (52). The core element (52) and the wrapper (48) are preferably made from a single sheet in the flat tobacco article (12) according to claim 1.

9. The flat tobacco represents the article thickness in a cross-section orthogonal to the article axis, and the core element represents the core thickness in a cross-section orthogonal to the article axis. The ratio between the core thickness and the article thickness is included in 0.2 to 0.8 in the flat tobacco article (12) according to claim 1.

10. The core element (52) is a thermal expansion element configured to expand while being heated in the flat tobacco article (12) according to claim 1.

11. An aerosol generating assembly (10), a flat tobacco article (12) according to any one of claims 1 to 10, and an aerosol generating device (11) extending along a device axis (Y) and including a heating chamber (20) between a closed end portion (24) and an opening (25), the heating chamber (20) including at least one heater (26), the aerosol generating assembly (10) including the aerosol generating device (11). The heating chamber (20) is configured to receive the flat tobacco article (12) through its opening (25), and the outer surface (60A) of the first layer faces the or one of the heaters (26) in the aerosol generating assembly (10).

12. The flat tobacco article (12) can be switched from a release configuration to a compression configuration in which the core element (52) is compressed and pressure is applied to the inner surfaces (60A, 60B). The aerosol generating assembly (10) according to claim 11, wherein the flat tobacco article (12) assumes a compressed configuration when inserted into the heating chamber (20).

13. The flat tobacco article (12) represents a cross-section orthogonal to the article axis (X) representing the article width (Wa) and the article thickness (Da), and the opening (25) of the heating chamber (20) represents the chamber width (Wc) and the chamber height (Dc). The aerosol generating assembly (10) according to claim 12, wherein the chamber height (Wc) is smaller than the article thickness (Da) in the release configuration.

14. A method of manufacturing a flat tobacco article according to any one of claims 1 to 10, the method comprising the following steps, namely providing a layer of elastic elements, preferably a layer of paper; forming a compressible three-dimensional core element from the layer of elastic material, the core having a thickness and a flat shape with first and second larger opposing sides; attaching a tobacco layer to the first side of the core element and the method preferably further comprises the step of attaching a second tobacco layer to the second side of the core element to form a clamping structure.

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