Tobacco articles with resistive layers and related aerosol-generating assemblies

Abstract

The present invention provides a tobacco article (12) configured to operate with an aerosol generating device comprising a pair of electrodes, Tobacco articles (12) - a substrate layer extending along an article axis (X); - a resistive layer configured to generate heat when a current flows between the electrodes, the resistive layer extending continuously along the article axis (X) and along a transverse direction (Y) perpendicular to the article axis (X), a heat transfer surface disposed adjacent to the base layer for transferring heat generated by the resistance layer to the base layer; a first contact surface opposite the heat transfer surface, the first contact surface having a contact portion (44) designed to be in electrical contact with at least one of the electrodes; a resistive layer defining The present invention relates to a tobacco article (12) comprising a tobacco portion (15) comprising:

Description

[Technical Field]

[0001] The present invention relates to a tobacco article comprising a resistive layer. The present invention also relates to an aerosol-generating assembly comprising such a tobacco article.

[0002] In particular, the aerosol generating assembly according to the present invention comprises an aerosol generating device configured to operate with a tobacco article comprising, for example, a solid substrate capable of forming an aerosol when heated. Thus, these types of aerosol generating devices, also known as non-combustion heated devices, are adapted to generate an aerosol for inhalation by heating rather than burning. [Background technology]

[0003] The popularity and use of risk-reducing or risk-modifying devices (also known as vaporizers) has grown rapidly in recent years as aids to assist regular smokers who wish to quit smoking traditional tobacco products such as cigarettes, cigars, cigarillos, and rolling tobacco. A variety of devices and systems are available that heat or warm a vaporizable substance, as opposed to burning tobacco in traditional tobacco products.

[0004] Commonly available risk reduction or risk modification devices are substrate-heated aerosol generating devices or heat-and-burn devices. These types of devices typically generate aerosol or vapor by heating an aerosol substrate containing moist tobacco or other suitable vaporizable material, typically to temperatures ranging from 150°C to 350°C. By heating the aerosol substrate rather than burning or combusting it, an aerosol is released that contains the ingredients desired by the user but is free of the toxic and carcinogenic by-products of combustion and burning. Furthermore, aerosols generated by heating tobacco or other vaporizable material typically do not contain the burnt or bitter taste that can be unpleasant to users due to combustion and burning, and therefore the substrate does not require sugars and other additives typically added to such materials to make the smoke and / or vapor more palatable to users.

[0005] To provide high user comfort, it is desirable to obtain rapid and efficient heating of the aerosol substrate. Some known aerosol generating devices that operate with tobacco articles include heaters configured to transfer heat to the aerosol substrate for heating. However, such heating methods may not be completely efficient and may result in heat loss. Summary of the Invention [Problem to be solved by the invention]

[0006] One of the objects of the present invention is to provide a tobacco article that can be heated in a rapid and efficient manner. [Means for solving the problem]

[0007] To this end, the present invention provides a tobacco article configured to operate with an aerosol-generating device comprising a pair of electrodes, the tobacco article comprising: a tobacco article extending along an article axis between a mouth end and a tobacco end, the tobacco article having a non-tobacco portion adjacent the mouth end and a tobacco portion adjacent the tobacco end; The tobacco part a substrate layer extending along the article axis; - a resistive layer configured to generate heat when a current flows between the electrodes, the resistive layer extending continuously along the article axis and along a transverse direction perpendicular to the article axis; a heat transfer surface disposed adjacent to the base layer for transferring heat generated by the resistance layer when the resistance layer contacts the pair of electrodes to the base layer; a first contact surface opposite the heat transfer surface, the first contact surface having a contact portion designed to be in electrical contact with at least one of the pair of electrodes; a resistive layer defining The present invention relates to a tobacco article comprising:

[0008] These features allow the resistive layer of the tobacco article to reliably heat the substrate layer. Because the resistive layer is included in the tobacco layer, the resistive layer can efficiently transfer heat to the substrate layer, thereby minimizing heat loss. For example, the resistive layer can be positioned adjacent to the substrate layer to maximize their common contact area. For example, the heat transfer surface can be defined by the substrate layer and extend along the entire surface facing the heat transfer surface.

[0009] Additionally, the resistive layer extends continuously along at least one axis and at least one transverse direction perpendicular to the axis. By "continuously extending" the resistive layer, it is understood that the resistive layer has no gaps or holes in the material forming the resistive layer along the corresponding axis / direction. The continuous extension of the resistive layer maximizes the contact area between its heat transfer surface and the substrate layer, which improves the efficiency of heat transfer to the substrate layer.

[0010] The tobacco article, and thus the resistance layer, may have a flat shape. The tobacco article may, for example, have a substantially rectangular parallelepiped shape. In this case, the transverse direction of its continuous extent corresponds to a linear axis perpendicular to the article axis and extending in a plane defining the resistance layer. In other embodiments, the tobacco article and the resistance layer may have any other suitable shape, for example, a cylindrical shape with a substantially circular cross section. In this case, the transverse direction may correspond to the circumferential direction of this shape.

[0011] The contact portion of the first contact surface is designed to be in direct or indirect electrical contact with the corresponding electrode. In the case of direct electrical contact, the electrode touches the contact portion without penetrating the resistive layer. In the case of indirect electrical contact, an intermediate conductive material is sandwiched between the contact portion and the corresponding electrode without penetrating the contact portion.

[0012] According to some embodiments, the resistive layer comprises, and is preferably made from, a carbon-based material.

[0013] According to some embodiments, the resistive layer comprises charcoal, and preferably the resistive layer does not comprise a polymer.

[0014] These characteristics allow the resistive layer to achieve an electrical resistivity suitable for heating the substrate layer to a target temperature. The resistive layer may contain a carbon-based material such as charcoal or graphite, which ensures its electrical resistance. In such cases, the charcoal or graphite content of the resistive layer may be 5% to 50%, advantageously 8% to 40%, and preferably 10% to 25% of its total mass.

[0015] The resistive layer may also include non-carbon ingredients such as glycerol, propylene glycol, gellan / xanthan gum, water, CMC binder, etc. These ingredients may be mixed with the carbon-based material to form a homogeneous mixture.

[0016] In an alternative embodiment, the resistive layer may be made solely from a carbon-based material such as charcoal.

[0017] According to some embodiments, the resistive layer comprises or consists of graphite.

[0018] The resistive layer can be polymer-free. By eliminating the polymer from the resistive layer, a lower resistance can be used, thereby requiring a lower voltage to generate heat, making it more suitable for handheld devices.

[0019] In either case, the resistive layer does not contain tobacco, which means, according to the present invention, that only the substrate layer contains tobacco.

[0020] The resistive layer may be formed from particles, such as charcoal particles, agglomerated with a binder. The binder may be a cellulose derivative or a gum. In particular, to produce such a resistive layer, carbon-containing particles, such as charcoal particles, may first be mixed with at least a binder and, optionally, water. In a preferred embodiment, this mixture forms a paste or dough, which may then be compressed into a layer. The mixture may then be solidified by curing and / or drying.

[0021] According to some embodiments, the resistant layer or at least some of its components are biodegradable. For example, the binder of the resistant layer may be biodegradable. Biodegradability may be defined as the process of biodegradation under controlled composting conditions, for example as defined according to the EN 13432 standard.

[0022] Thanks to these characteristics, tobacco articles have a lower impact on the environment.

[0023] According to some embodiments, the electrical resistance of the resistive layer is comprised between 0.5 ohm and 1.5 ohm, advantageously substantially equal to 1 ohm.

[0024] These features result in less voltage being required to generate the heat necessary to generate the aerosol.

[0025] According to some embodiments, the resistive layer extends along the article axis and transverse direction substantially along the entire area of ​​the surface defined by the substrate layer.

[0026] These features allow for uniform heating of the substrate layer, thereby avoiding underheated and overheated areas that can reduce the quality of the aerosol.

[0027] According to some embodiments, the article further comprises a wrapper extending along the article axis and transversely, the wrapper encasing the substrate layer together with the resistive layer; The wrapper defines a window that bounds a contact portion of the first contact surface of the resistive layer.

[0028] These features allow the tobacco article to be ready for use when removed from the package, and in particular, the contact portions can directly or indirectly engage with corresponding electrodes through windows formed in the wrapper, eliminating the need for the user to prepare the tobacco article before inserting it into the device.

[0029] In some embodiments, the window in the wrapper can be formed by an opening. In this case, the contact between the contact portion and the electrode is direct contact. Thus, the contact portion forms an uncovered portion of the resistive layer. The wrapper can be made, for example, entirely from a non-conductive material.

[0030] In some other embodiments, the window may be formed from a conductive material (e.g., aluminum, etc.). In this case, the contact between the contact portion and the electrode is indirect. The wrapper may be made from a non-conductive material that incorporates a portion of conductive material that forms the window. The conductive portion may be bonded to the non-conductive portion of the wrapper, for example, prior to wrapping.

[0031] According to some embodiments, the tobacco portion comprises only one substrate layer and only one resistive layer.

[0032] These features allow the tobacco article to form a compact shape while ensuring efficient heat transfer from the resistive layer to the substrate layer within the article.

[0033] According to some embodiments, the contact portion of the first contact surface is adjacent to the non-tobacco portion.

[0034] Thanks to these features, the contact portion can be positioned at one of the ends of the resistive layer along the article axis, thus maximizing the area of ​​the resistive layer that provides resistance, and therefore heat, when current flows through it.

[0035] According to some embodiments, the resistive layer further defines a second contact surface extending transversely at the tobacco end perpendicular to the article axis and designed to contact the other electrode of the pair of electrodes.

[0036] These features allow the second contact surface to be naturally uncovered by the wrapper, since the wrapper extends generally around the article axis and does not cover the sides formed at each end of the article. Additionally, contact between the second contact surface and the corresponding electrode can be particularly reliable due to the insertion direction that presses the second contact surface against the electrode.

[0037] Advantageously, the second contact surface extends along only a portion of such side surface, the remainder of which is formed by the substrate layer, which is also wrapper-free, so that an airflow path can be formed through the substrate layer along the article axis.

[0038] In some embodiments, the substrate layer forms airflow channels on at least one of its surfaces. For example, airflow channels may be formed on the surface of the substrate layer that contacts the resistive layer. Thus, airflow passing through these channels upon a user's inhalation may be heated by the resistive layer. Conversely, airflow passing through airflow channels formed on the opposite surface of the substrate layer (i.e., the surface that is not in contact with the resistive layer) is not directly heated by the resistive layer, but is heated only by passing through the substrate layer.

[0039] According to some embodiments, the article forms a substantially flat shape; Advantageously, the tobacco portion comprises a plurality of airflow channels extending along the article axis.

[0040] A flat shape is advantageous in the present invention because it allows maximizing the surface of the substrate portion in contact with the resistive layer, and in addition, the airflow channels as defined above can be more easily positioned and geometrically and dimensionally defined in a flat shaped article.

[0041] The present invention also provides - a tobacco article according to any one of the preceding claims; - an aerosol-generating device, a cavity extending along the device axis and configured to receive a tobacco article; a pair of electrodes disposed in the cavity so as to contact the resistive layer of the tobacco article; an aerosol generating device comprising: The present invention relates to an aerosol generation assembly comprising:

[0042] According to some embodiments, the pair of electrodes comprises a first electrode arranged on at least one side wall of the cavity extending along the device axis and designed to contact a contact portion of a first contact surface of the resistive layer.

[0043] The first electrode may protrude slightly from the sidewall of the cavity so as to abut against a contact portion of the tobacco article when the tobacco article is inserted into the cavity. This may improve electrical contact between the first contact surface of the resistive layer and the first electrode. In some embodiments, the first electrode may be attached to a resilient element, such as a spring, that applies a force to the first electrode to abut against the first contact surface.

[0044] According to some embodiments, the first electrode comprises two opposing portions disposed on opposing sidewalls of the cavity.

[0045] Thanks to these features, the tobacco article can be inserted into the cavity in at least two different orientations without affecting its operation. In particular, for a flat-shaped tobacco article, it is clear that there are two possible orientations for inserting the article into the cavity. By providing two opposing portions, the first electrode can always contact the first contact surface of the resistive layer, regardless of how the article is inserted into the cavity.

[0046] According to some embodiments, the pair of electrodes further comprises a second electrode at least partially forming an abutting wall of the cavity and extending perpendicular to the device axis.

[0047] The second electrode can extend along the entire area of ​​the corresponding side of the tobacco article. Thus, the second electrode can contact the second contact surface of the resistive layer regardless of how the article is inserted into the cavity. In addition, the second electrode can define one or more holes for airflow through the substrate layer. When airflow channels are provided in the substrate layer, the holes in the second electrode are positioned to face these channels.

[0048] According to some embodiments, the aerosol generating device further comprises a controller configured to control the temperature of the substrate layer by measuring the electrical resistance of the resistive layer.

[0049] Thanks to these features, the operation of the aerosol generating device can be directly controlled using the electrical resistance measurements. For example, the temperature of the substrate layer can be directly derived from these measurements. Therefore, there is no need to provide an additional sensor, such as a temperature sensor, to ensure control of the aerosol generating device.

[0050] The invention and its advantages will be better understood from a reading of the following description, given purely by way of non-limiting example, and with reference to the accompanying drawings, in which: [Brief explanation of the drawings]

[0051] [Figure 1]1 is a schematic diagram of an aerosol generation assembly according to the present invention, the aerosol generation assembly comprising an aerosol generation device according to the present invention and a tobacco article, the tobacco article having been removed from the aerosol generation device. [Figure 2] FIG. 2 is a perspective view of the tobacco article of FIG. 1. [Figure 3] 3A-3C are different views of the tobacco article of FIG. 2 (A: top view, B: front view, C: bottom view). [Figure 4] 4 is a cross-sectional view of the tobacco article of FIG. 2 along plane IV. [Figure 5] FIG. 2 is a schematic diagram of the aerosol-generating assembly of FIG. 1, with a tobacco article inserted into the device. DETAILED DESCRIPTION OF THE INVENTION

[0052] Before the present invention is described, it is to be understood that the invention is not limited to the details of construction set forth in the following description. 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.

[0053] As used herein, the terms "aerosol-generating device" or "device" may include a vaping device for delivering an aerosol, including an aerosol for vaping, to a user using a heater element, as described in more detail below. The device may be portable. "Portable" may refer to a device used while held by a user. The device may be adapted to generate a variable amount of aerosol (as opposed to a fixed amount of aerosol), for example, by activating a heater element for a variable amount of time, which may be controlled by a trigger. The trigger may be user-activated, such as a vaping button and / or an inhalation sensor. The inhalation sensor may be sensitive to inhalation intensity and inhalation duration, allowing for the provision of a variable amount of vapor (to mimic the smoking effect of a conventional combustion-type smoking article, such as a cigarette, cigar, or pipe). The device may include a temperature regulation control for driving the temperature of the heated aerosol-generating material (aerosol precursor) to a specific target temperature and then maintaining the temperature at a target temperature that can efficiently generate aerosol.

[0054] As used herein, the term "aerosol" can include a suspension of vaporizable material as one or more of solid particles, liquid droplets, or gas. The suspension can be in a gas, including air. Aerosol herein generally refers to / can include a vapor. Aerosol can include one or more components of vaporizable material.

[0055] As used herein, the terms "vaporizable material" or "precursor" may refer to smokable material, which may include, for example, nicotine or tobacco and an aerosol-forming agent. The 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 and glycerol), 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.

[0056] Figure 1 shows an aerosol-generating assembly 10 including an aerosol-generating device 11 and a tobacco article 12. The aerosol-generating device 11 is intended to operate with a tobacco article 12, which is shown in more detail in Figures 2-4.

[0057] The tobacco article 12 extends along an article axis X and a transverse direction Y perpendicular to the article axis X. In the example of Figures 2-4, the tobacco article 12 has a flat shape, and its transverse direction Y represents a linear axis perpendicular to the article axis X and, together with the article axis X, forms the spreading surface of the tobacco article 12. It should be understood that the "flat shape" of such a tobacco article means that its depth (i.e., the dimension extending perpendicular to the spreading surface) is less than a small fraction (e.g., at least one-fifth or at least one-tenth) of any of its other dimensions (e.g., length or width) measured at the spreading surface.

[0058] According to other embodiments, the tobacco article 12 may have any other suitable shape, for example a cylindrical shape with a substantially circular cross section, in this last case the transverse direction Y should be understood as the circumferential direction extending around the article axis X.

[0059] 2, the tobacco article 12 extends along the article axis X and presents a rectangular parallelepiped with external dimensions L×W×D. In a typical example, the length L of the article 12 along the article axis X is substantially equal to 33 mm, while its width W and depth D are substantially equal to 12 mm and 1.2 mm, respectively. According to different examples, the values ​​L, W, and D can be selected within a range of, for example, ±40%. The depth D of the tobacco article 12 is formed by a pair of parallel walls 13A, 13B, hereinafter referred to as narrow walls 13A, 13B, and the width W of the substrate is formed by a pair of parallel walls 14A, 14B, hereinafter referred to as wide walls 14A, 14B. In some embodiments, the edges between the wide and narrow walls 13A, 13B, 14A, 14B, may be rounded.

[0060] The tobacco article 12 comprises a tobacco portion 15 and a non-tobacco portion 16 arranged contiguously along the article axis X. The tobacco portion 15 may, for example, be longer than the non-tobacco portion 16. For example, the length L2 of the tobacco portion 15 along the article axis X may be substantially equal to 25 mm, and the length L1 of the non-tobacco portion 16 along the article axis X may be substantially equal to 8 mm. These dimensions are given by way of example only and may vary considerably depending on various embodiments of the invention. The tobacco portion 15 defines a tobacco end 18 of the article 12, and the non-tobacco portion 16 defines a mouth end 20 of the article 12. The tobacco portion 15 and the non-tobacco portion 16 may be secured to one another by a wrapper 21 extending around the substrate axis X. The wrapper 21 forms the narrow and broad walls 13A, 13B, 14A, 14B of the tobacco article 12. In some embodiments, the wrapper 21 is formed from the same wrapping sheet. In some other embodiments, the wrapper 21 is formed by separate wrapping sheets that separately wrap the sections 15, 16 and are secured together by any other suitable means. The wrapper 21 may comprise, for example, paper, and / or a nonwoven fabric, and / or aluminum foil. In some embodiments, the wrapper 21 is formed entirely from a non-conductive material. In some other embodiments, the wrapper 21 is formed partially from a conductive material and partially from a non-conductive material, as described in more detail below. The wrapper 21 may be porous or air-impermeable, forming a plurality of airflow channels within the article 12 that extend between the tobacco end 18 and the mouth end 20. Advantageously, the wrapper 21 does not cover the transverse end faces 25, 26 of the tobacco article 12 that extend perpendicular to the article axis X and are formed by the tobacco portion 15 at the tobacco end 18 and the non-tobacco portion 16 at the mouth end 20, respectively.

[0061] The non-tobacco portion 16 comprises a core 27, also shown in part A of Figure 3, which corresponds to a top view of the tobacco article 12. The core 27 is intended, for example, to function as a cooler to slightly cool the vapor before it is inhaled by the user, and may comprise, for example, corrugated paper for this purpose. The core 27 may be formed into a stable shape via an extrusion and / or rolling process. Advantageously, the core 27 is disposed inside the non-tobacco portion 16 so as to fully contact the inner surface of the wrapper 21, as shown in part A of Figure 3, and defines this non-tobacco portion 16. In other words, there is no gap between the inner surface of the wrapper 21 and the core 27 in the non-tobacco portion 16. The non-tobacco portion 16 is intended, for example, to be in direct contact with the user's mouth or to be received within a separate mouthpiece.

[0062] In a particular embodiment of the present invention (not shown), the non-tobacco portion 16 defines a plurality of ventilation holes arranged along the entire circumference of the non-tobacco portion 16, for example, along two axes perpendicular to the article axis X. In other words, according to this particular embodiment, ventilation holes are arranged in each of the narrow walls 13A, 13B and the wide walls 14A, 14B of the substrate. According to another example, ventilation holes are arranged only in the wide walls 14A, 14B, or preferably only in one of the wide walls 14A, 14B. In both examples, the ventilation holes may be aligned with the corresponding wall or walls of the article 12 perpendicular to the article axis X and may be spaced apart by the same distance. The ventilation holes allow fresh air to flow into the interior of the article 12 to achieve a particular vaping / tasting effect. In a preferred embodiment of the present invention, ventilation holes are not provided.

[0063] The tobacco portion 15 exhibits a two-layer structure. As shown in part C of Figure 3, which corresponds to a bottom view of the tobacco article 12, and in Figure 4, which corresponds to a longitudinal cross section thereof, the tobacco portion 15 comprises a substrate layer 30 and a resistance layer 32. Advantageously, the tobacco portion 15 is not provided with any other layers.

[0064] The substrate layer 30 comprises a vaporizable material as defined above. In particular, the substrate layer 30 comprises cut tobacco and / or tobacco particles.

[0065] In one possible embodiment, the substrate layer is formed of a compressed layer of aerosol material comprising an inhalable agent containing tobacco particles and / or at least one stimulant and / or flavor, as described in WO 2021094365, a gelling agent for gelling the aerosol material, a disintegrant and / or a thickening stabilizer, and an aerosol-forming agent. The gelling agent may be a non-protein-containing polysaccharide and / or may include gellan gum, lecithin, agar, and / or a mixture thereof. The aerosol-forming agent may be present in an amount of 20 to 70% by weight of the total weight of the vaporizable material. The aerosol-forming agent may be glycerol, propylene glycol, ethanol, water, or a combination thereof. The disintegrant and / or a thickening stabilizer may be carboxymethylcellulose and / or a hydroxyalkylated carbohydrate. Preferably, this is purified CMC, such as Ceroga 4550 C or CEOKOL 2000 (CERoeper GmbH).

[0066] The substrate layer 30 extends inside the tobacco portion 15 along the article axis X and forms two oppositely facing sides. In particular, the substrate layer 30 is positioned so that one of its sides contacts the wrapper 21 and the other side contacts the resistive layer 32. In some embodiments, the substrate layer 30 further comprises air flow channels, e.g., in at least one or both of its surfaces, extending along the article axis X. The air flow channels may be formed by extruding a vaporizable material or by stamping.

[0067] The resistive layer 32 forms a layer that extends continuously along the article axis X and the transverse direction Y. For example, the resistive layer 32 may extend along the entire area of ​​the substrate layer 30. In particular, the resistive layer 32 is in at least partial contact with the substrate layer 30 and forms a heat transfer surface 34 designed to transfer heat from the resistive layer 32 to the substrate layer 30.

[0068] The resistive layer 32 comprises an electrically resistive material capable of generating heat when an electric current passes through it when it is engaged between two external electrodes. The resistive layer 32 may comprise a carbon-based material, such as charcoal, which ensures its electrical resistance. In such a case, the charcoal portion of the resistive layer may comprise 5% to 50%, advantageously 8% to 40%, and preferably 10% to 25% of its total mass.

[0069] To be engaged between two external electrodes, the resistive layer 32 defines a first contact surface 41 and a second contact surface 42 .

[0070] The first contact surface 41 is located opposite the heat transfer surface 34 and comprises a covered portion covered by the wrapper 21 and a contact portion 44 designed to contact an external electrode. In particular, as shown in FIGS. 2-4 , the contact portion 44 may be formed by a portion of the first contact surface 41 facing a window 46 formed in the wrapper 21. In some embodiments, the window 46 may be formed by an opening in the wrapper. In this case, the contact portion 44 does not include the wrapper (i.e., forms an uncovered portion) and is designed to directly contact the external electrode. In some other embodiments, the window 46 is formed by a conductive material. In this case, the contact portion 44 is designed to contact the external electrode via the conductive material. Advantageously, the window 46 is formed on the broad walls 14A, 14B of the article 12 in the portion of the wrapper 21 covering the tobacco portion 15 adjacent to or on the border of the non-tobacco portion 16. The window 46 may have a rectangular shape and extend along the entire width of the corresponding broad wall 14A, 14B. The length L3 of the window 46 along the article axis X is less than the length L2 of the tobacco portion 15, for example by at least 50%, advantageously 70%, preferably 80% or 90%.

[0071] The second contact surface 42 is formed by a portion of the resistive layer 32 that forms the cross-section 25 of the tobacco article 12 on the tobacco end 18 of the tobacco article 12. The second contact surface 42 is not covered by the wrapper 21 and extends perpendicular to the first contact surface 41 at the opposite end of the resistive layer 32. Thus, the distance between the first contact surface 41 and the second contact surface 42 within the resistive layer 32 can be maximized.

[0072] 1 , the aerosol-generating device 11 comprises a device body 50 that extends along a device axis Z and defines a cavity 52 configured to at least partially receive a tobacco article 12. In particular, the cavity 52 forms a shape complementary to that of the tobacco article 12. Additionally, in the case of a flat-shaped tobacco article, the cavity 52 is configured to receive the tobacco article 12 according to two different manners in which the article axis X coincides with the device axis Z, and the non-tobacco portion 16 either protrudes from the cavity 52 or is disposed within the opening of the cavity, as shown in FIG. 5 . Rotating the tobacco article 12 by 180 degrees about the article axis X switches between the two different insertion manners of the tobacco article 12.

[0073] Device body 50 defines an interior space of device 11 that houses various elements designed to perform different functions of device 11. This interior space may house, for example, a battery 54 for powering device 11 and a controller 56 for controlling the operation of device 11.

[0074] The aerosol generating device 11 further comprises a pair of electrodes designed to engage with the resistive layer 32. In particular, the pair of electrodes comprises a first electrode 61 designed to contact the first contact surface 41 of the resistive layer 32 and a second electrode 62 designed to contact the second contact surface 42 of the resistive layer 32.

[0075] As shown in FIG. 1 , the second electrode 62 may at least partially form the abutment wall 65 of the cavity 52. ​​The abutment wall 65 is perpendicular to the device axis Z and is designed to contact the cross section 25 formed on the tobacco end 18 of the article 12 when the article is received in the cavity 52. ​​Advantageously, the second electrode 62 is positioned to contact the second contact surface 42 of the resistive layer 32 regardless of how the tobacco article 12 is inserted. To this end, the abutment wall 65 may be completely formed by the second electrode 62, which may have one or more holes formed therein. These holes face the substrate layer 30 when the article 12 is inserted into the cavity 52 and form entrances to the airflow channels formed by the substrate layer 30. These holes may be formed, for example, in a central portion of the second electrode 62. According to another embodiment, the second electrode 62 is formed by two distinct portions spaced apart from each other in the center of the abutting wall 62 to form an entrance to the airflow channel formed by the substrate layer 30 between these portions.

[0076] The first electrode 61 is integrated into the sidewall of the cavity 52 so as to be in electrical contact with the contact portion 44 of the first contact surface 41 when the tobacco article 12 is inserted into the cavity 52. ​​In particular, as shown in FIG. 5 , the first electrode 61 is arranged parallel to the device axis Z so as to be aligned with the contact portion 44 of the first contact surface 41 when the tobacco article 12 is inserted into the cavity. As shown in FIGS. 1 and 5 , in the case of a flat-shaped tobacco article 12, the first electrode 61 may form two opposing portions located on opposite sidewalls of the cavity 52. ​​Thus, the contact portion 44 of the second contact surface 42 can contact one of these portions regardless of how the tobacco article 12 is inserted into the cavity 52. ​​Each portion of the first electrode 61 may have substantially the same dimensions and shape as the window 46 of the wrapper 21. In addition, each portion of the first electrode 61 may protrude slightly from the corresponding sidewall of the cavity 52 so as to abut the contact portion 44 of the second contact surface 42 when the tobacco article 12 is inserted into the cavity 52. ​​In some embodiments, each portion of the first electrode 61 may be mounted on a resilient element for this purpose. In some embodiments, each portion of the first electrode 61 forms a flat and substantially smooth surface designed to make electrical contact with the contact portion 44 of the first contact surface 41.

[0077] The electrodes 61, 62 are connected to the battery 54 via a controller 56. The controller 56 can thus control the power on each electrode 61, 62 and, consequently, the current passing through the resistive layer 32 and the heat generated by this layer. In some embodiments, the controller 56 is configured to control the temperature of the substrate layer 30 by measuring the resistance of the resistive layer 32 and controlling the power on the electrodes 61, 62 based on these measurements. Resistance measurements can be correlated with temperature values, such as by using a look-up table stored in the memory of the controller 56. Control of the resistance and temperature may be used to ensure that heating stays within a safe temperature range and / or to control that a particular temperature profile is followed during a vaping session.

Claims

1. A tobacco article (12) configured to operate with an aerosol generating device (11) comprising a pair of electrodes (61, 62), the tobacco article (12) extends along an article axis (X) between a mouth end (20) and a tobacco end (18), and comprises a non-tobacco portion (16) adjacent the mouth end (18) and a tobacco portion (15) adjacent the tobacco end (18); The tobacco portion (15) a substrate layer (30) extending along the article axis (X); a resistive layer (32) configured to generate heat when a current flows between the electrodes (61, 62), the resistive layer (32) extending continuously along the article axis (X) and along a transverse direction (Y) perpendicular to the article axis (X), a heat transfer surface (34) disposed adjacent to the base layer (30) for transferring heat generated by the resistance layer (32) to the base layer (30) when the resistance layer (32) comes into contact with the pair of electrodes (61, 62); a first contact surface (41) opposite the heat transfer surface (34), the first contact surface (41) having a contact portion (44) designed to be in electrical contact with at least one electrode (61, 62) of the pair of electrodes (61, 62); a resistive layer (32) defining A tobacco article (12) comprising:

2. 10. The tobacco article (12) of claim 1, wherein the resistive layer (32) comprises, and is preferably made from, a carbon-based material.

3. the resistive layer (32) comprises charcoal; The tobacco article (12) of claim 2, wherein the resistive layer (32) is preferably polymer-free.

4. A tobacco article (12) according to any one of claims 1 to 3, wherein the electrical resistance of said resistive layer (32) is comprised between 0.5 ohms and 1.5 ohms, advantageously substantially equal to 1 ohm.

5. A tobacco article (12) according to any one of claims 1 to 4, wherein the resistance layer (32) extends along the article axis (X) and the transverse direction (Y) substantially along the entire area of ​​the surface defined by the substrate layer (30).

6. a wrapper (21) extending along the article axis (X) and the transverse direction (Y) and enclosing the substrate layer (30) together with the resistive layer (32); A tobacco article (12) according to any one of claims 1 to 5, wherein the wrapper (21) defines a window (46) that bounds the contact portion (44) of the first contact surface (41) of the resistance layer (32).

7. A tobacco article (12) according to any one of claims 1 to 6, wherein the tobacco portion (15) comprises only one substrate layer (30) and only one resistance layer (32).

8. A tobacco article (12) according to any one of claims 1 to 7, wherein the contact portion (44) of the first contact surface (41) is adjacent to the non-tobacco portion (16).

9. A tobacco article (12) according to any one of claims 1 to 8, wherein the resistive layer (32) further defines a second contact surface (42) extending perpendicular to the article axis (X) along the transverse direction (Y) at the tobacco-side end (18) and designed to contact the other electrode (61, 62) of the pair of electrodes (61, 62).

10. forming a substantially flat shape; Advantageously, a tobacco article (12) according to any one of claims 1 to 9, wherein said tobacco portion (15) comprises a plurality of airflow channels extending along said article axis (X).

11. A tobacco article (12) according to any one of claims 1 to 10; An aerosol generating device (11), comprising: a cavity (52) extending along a device axis (Z) and configured to receive said tobacco article (12); a pair of electrodes (61, 62) disposed in the cavity (52) and configured to contact the resistive layer (32) of the tobacco article (12); an aerosol generating device (11) comprising: An aerosol generating assembly (10) comprising:

12. 12. The aerosol generation assembly (10) of claim 11, wherein the pair of electrodes (61, 62) is arranged on at least one side wall of the cavity (52) extending along the device axis (Z) and comprises a first electrode (61) designed to contact the contact portion (44) of the first contact surface (41) of the resistive layer (32).

13. 13. The aerosol generation assembly (10) of claim 12, wherein the first electrode (61) comprises two opposing portions arranged on opposite side walls of the cavity (52).

14. An aerosol generation assembly (10) as described in claim 12 or 13, wherein the pair of electrodes (61, 62) at least partially form an abutting wall (65) of the cavity (52) and further comprises a second electrode (62) extending perpendicular to the device axis (Z).

15. 15. An aerosol generating assembly (10) according to any one of claims 11 to 14, wherein the aerosol generating device (11) further comprises a controller (56) configured to control the temperature of the substrate layer (30) by measuring the electrical resistance of the resistive layer (32).

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