Susceptor device for inductively heating an aerosol-forming substrate

Abstract

[0009] A susceptor apparatus for inductively heating an aerosol-forming substrate is provided, comprising: at least one susceptor body having a susceptor body surface comprising a first susceptor material; and a first heat spread layer comprising a first heat spread material, the first heat spread layer extending over at least a portion of the susceptor body surface and in thermal contact with or in thermal proximity to a portion of the susceptor body surface, the first heat spread material having a thermal conductivity at least 3.5 times, preferably 4 times, and more preferably 5 times greater than the thermal conductivity of the first susceptor material. The present invention also relates to an inductively heatable aerosol-generating article comprising such a susceptor apparatus.

Description

[Technical Field]

[0001] The present invention relates to a susceptor device for inductively heating an aerosol-forming substrate. The present invention further relates to an inductively heated aerosol-generating article comprising such a susceptor device, and to an aerosol-generating device comprising such a susceptor device. [Background technology]

[0002] Aerosol-generating articles including at least one aerosol-forming substrate capable of forming an inhalable aerosol upon heating are generally known. To heat the aerosol-forming substrate, the aerosol-generating article can be housed within an aerosol-generating device equipped with an electric heater. The heater can be an induction heater equipped with an induction source. The induction source is configured to generate an alternating current electromagnetic field to inductively heat the susceptor device by at least one of eddy currents and hysteresis losses, depending on the electrical and magnetic properties of the susceptor device. The susceptor device can be an integral part of the aerosol-generating article, disposed in thermal proximity or direct physical contact with the aerosol-generating substrate to be heated, or can be part of the aerosol-generating device. During operation of the device, volatile compounds are released from the heated aerosol-forming substrate in the aerosol-generating article and entrained in the airflow drawn through the aerosol-generating article during a user's puff. As the released compounds cool, they condense to form an aerosol.

[0003] However, depending on the geometry and internal structure of the susceptor device, heating of the aerosol-generating substrate can sometimes be unsatisfactory. In particular, heating of the substrate can be uneven due to different temperature regions across the substrate, leading to, for example, inefficiencies in aerosol generation, inconsistencies in the perception of the aerosol, or the emission of undesirable volatile compounds.

[0004] It would therefore be desirable to have a susceptor apparatus that possesses the advantages of prior art solutions while mitigating their limitations. In particular, it would be desirable to achieve more uniform heating of the aerosol-generating substrate. Summary of the Invention

[0005] According to one embodiment of the present invention, there is provided a susceptor apparatus for inductively heating an aerosol-forming substrate. The susceptor apparatus includes at least one susceptor body having a susceptor body surface including a first susceptor material and a first heat spreading layer including a first heat spreading material. The first heat spreading layer extends over at least a portion of the susceptor body surface in thermal contact with or in thermal proximity to a portion of the susceptor body surface. The first heat spreading material further has a thermal conductivity at least 3.5 times, preferably 4 times, and more preferably 5 times greater than the thermal conductivity of the first susceptor material.

[0006] The use of a susceptor device that includes a heat spreading layer provides several advantages over other susceptor devices.

[0007] The heat spreading layer improves the distribution and dissipation of the heat generated across the surface of the susceptor device, thus enabling a more uniform temperature distribution across the surface of the susceptor device while avoiding temperature hot spots on the surface of the susceptor device, thereby improving heating of the aerosol-generating substrate and achieving a uniform temperature distribution across the aerosol-generating substrate.

[0008] According to another aspect of the present invention, there is provided a susceptor apparatus for inductively heating an aerosol-forming substrate. The susceptor apparatus includes at least one susceptor body having a susceptor body surface including a first susceptor material and a first heat spreading layer including a first heat spreading material. The first heat spreading layer extends over at least a portion of the susceptor body surface in thermal contact with or in thermal proximity to a portion of the susceptor body surface. The first susceptor material has a thermal conductivity greater than 25 W / (m K), particularly greater than 30 W / (m K), and more particularly greater than 40 W / (m K). For each of these values ​​of thermal conductivity of the first susceptor material, the first heat spreading material may have a thermal conductivity at least 1.5 times, preferably 2 times, more preferably 2.5 times, and particularly 3 times greater than the thermal conductivity of the first susceptor material.

[0009] The first heat spreading material is preferably a carbon allotrope, more preferably graphite or graphene, which are known to exhibit high thermal conductivity values ​​and can be provided as very thin layers, improving the thermal properties of the susceptor apparatus without substantially increasing the volume and mass of the susceptor apparatus.

[0010] The first heat diffusion material may preferably be provided as a graphite sheet, more preferably as a pyrolytic graphite sheet. The graphite sheet has the advantage of being flexible and easy to cut, and therefore can be adapted and / or cut to different shapes of the susceptor device. The graphite sheet is preferably bonded to the susceptor body with a temperature-resistant adhesive, which may also be non-hazardous when used to heat the aerosol-generating product.

[0011] The graphite sheet preferably has a thickness of from 1 micrometer to 200 micrometers, more preferably from 5 micrometers to 20 micrometers, and even more preferably substantially 10 micrometers.

[0012] Alternatively, the first heat spreading material may be provided as graphene. Thus, the graphene may be deposited on the susceptor body surface by a vapor deposition method, preferably a chemical vapor deposition (CVD) method or a catalytic chemical vapor deposition (CCVD) method. When provided as graphene, the first heat spreading material may include one graphene layer or several graphene layers.

[0013] In yet another alternative, the first heat spreading material may be a metal, preferably selected from the group including copper, copper alloys, nickel, nickel alloys, aluminum, and aluminum alloys.

[0014] The first heat spreading layer preferably has a thickness of 2 to 100 micrometers, more preferably 3 to 60 micrometers, even more preferably 5 to 20 micrometers, and particularly preferably 12 to 16 micrometers. For example, the first heat spreading layer may have a thickness of 3 to 30 micrometers, or 30 to 60 micrometers.

[0015] Preferably, an isolation layer may be disposed between the susceptor body and the first heat spreading layer. The isolation layer may preferably include at least one of an electrical insulating layer, a diffusion prevention layer, a temperature marker layer having a specific Curie temperature, and a protective layer. The isolation layer may be advantageous for providing additional functionality to the susceptor device. The electrical insulating layer may be advantageous for avoiding the "skin effect" in the susceptor device, in which induced eddy currents at high frequencies tend to flow primarily at the outer surface of the susceptor. In particular, the induced eddy currents tend to flow between the outer surface and a level called skin depth. By providing an electrical insulating layer between the susceptor body and the first heat spreading layer, the induced eddy currents can be enclosed by the susceptor body, which can provide more energy loss and, therefore, more heat.

[0016] The temperature marker layer can be advantageous in determining whether the susceptor device has reached a predetermined temperature.

[0017] To this end, the temperature marker layer may comprise a temperature marker material selected to be magnetic (ferromagnetic or ferrimagnetic) and have a Curie temperature corresponding to a predetermined temperature of the susceptor device. At that Curie temperature, the magnetic permeability of the temperature marker material decreases, causing its magnetic properties to change from ferromagnetic or ferrimagnetic to paramagnetic. The change in magnetic properties is accompanied by a temporary change in the electrical resistance of the temperature marker layer and, therefore, the susceptor device. Therefore, by monitoring the corresponding change in current through the induction source used to heat the susceptor device, it can be determined when the temperature marker material has reached its Curie temperature, and therefore, when the predetermined temperature point of the susceptor device has been reached.

[0018] A protective layer can be advantageous in providing protection from corrosion. Accordingly, as used herein, the term "protective layer" refers to a layer of a susceptor device that consists of or includes a corrosion-resistant material to protect materials disposed thereunder from corrosion. The corrosion-resistant material may be any suitable material that is resistant to corrosion. The corrosion-resistant material may include at least one of a corrosion-resistant metal, an inert metal, a corrosion-resistant alloy, a corrosion-resistant organic coating, a glass, a ceramic, a polymer, a corrosion-resistant paint, a wax, or a grease.

[0019] The diffusion barrier layer can be advantageous for providing a barrier between the susceptor body and the first heat spreading layer, for example, to prevent ion diffusion and the buildup of undesired electrical potentials within the susceptor device. Therefore, as used herein, the term "diffusion barrier layer" refers to a layer of the susceptor device that consists of or includes a diffusion barrier material that acts as a barrier to prevent material diffusion from and / or to the underlying material of the susceptor device. For example, the diffusion barrier layer can be configured to prevent metal migration from the susceptor device material to the aerosol-forming substrate or between different layers of the susceptor device. By way of example, the diffusion barrier layer may have a thickness of 6 micrometers and may include or consist of nickel or a nickel alloy. This is particularly advantageous for preventing ion diffusion from the heat spreading layer into the susceptor body when a metallic heat spreading layer, e.g., copper or a copper alloy, which may have a thickness of 12 to 16 micrometers, is used. In this example, the susceptor body may preferably comprise or consist of AISI 430 steel susceptor material and may be up to 60 micrometers thick.

[0020] On the side facing the susceptor device, the first heat spreading layer may additionally or alternatively be at least partially coated with at least one of an electrical insulating layer, a diffusion barrier layer, a temperature marker layer having a specific Curie temperature, and a protective layer, which may have the same functions and properties as the respective layers described above with respect to the separation layer.

[0021] Preferably, the susceptor body is a substantially planar element, and the susceptor body surface comprises a first susceptor body major surface and an opposing second susceptor body major surface. This has the advantage that the susceptor body precursor can be provided as a strip or sheet, and the susceptor body can be cut from the strip or sheet to the desired shape and size. Alternatively, the susceptor device precursor can be provided as a strip or sheet, and the susceptor device can be cut from the strip or sheet to the desired shape and size. Of course, the susceptor device intermediate product can also be provided as a strip- or sheet-like precursor.

[0022] The first heat spreading layer may preferably extend across at least a portion of at least one of the first susceptor body major surface and the second susceptor body major surface.

[0023] Alternatively, the first heat spreading layer may extend over at least a portion of the first susceptor body major surface, and the susceptor apparatus may further comprise a second heat spreading layer comprising a second heat spreading material, the second heat spreading layer extending over at least a portion of the second susceptor body major surface and in thermal contact or thermal proximity with a portion of the second susceptor body major surface, which is advantageous in that at least a portion of both the first and second susceptor body major surfaces are provided with the first and second heat spreading layers, respectively, thus providing the benefit of heat spreading layers on both opposing sides of the susceptor apparatus.

[0024] Preferably, the first heat spreading layer extends over the entire first susceptor body major surface and / or the second heat spreading layer extends over the entire second susceptor body major surface.

[0025] Preferably, the first heat spreading layer and the second heat spreading layer may be identical in at least one of the following characteristics: heat spreading material, heat spreading layer thickness, heat spreading layer width, heat spreading layer length, and heat spreading layer area.

[0026] When the susceptor body is provided as a substantially planar element, the term "width" of the heat spreading layer, as used herein, refers to the dimension of the heat spreading layer extending along a first of its major axes. Similarly, the term "length" refers to the dimension of the heat spreading layer extending along a second major axis perpendicular to the first axis. Finally, the term "area" refers to the dimension of the surface of the heat spreading layer extending along a given width and a given length.

[0027] Preferably, the susceptor body may be a multi-layer susceptor body, which may comprise at least two layers, in particular two layers, or three layers or four layers.

[0028] The susceptor body may preferably include a layer made of a first susceptor material and a temperature marker layer having a specific Curie temperature. The layer made of the first susceptor material and the temperature marker layer may be adjacent layers. Furthermore, the susceptor body may further include a protective layer. The protective layer may preferably be disposed on the temperature marker layer opposite the layer made of the first susceptor material. The layer made of the first susceptor material and the temperature marker layer may be closely bonded to each other. Similarly, the protective layer and the temperature marker layer, if present, may be closely bonded to each other. For example, one of the layers may be plated, vapor-deposited, coated, clad, or welded onto the other of the layers. Similarly, one of the layers may be applied to the other of the layers by spraying, dip coating, roll coating, electroplating, or cladding. Any of the above configurations fall within the scope of the term "closely bonded" as used herein.

[0029] The susceptor body may, in an alternative configuration, be rod-shaped, with the susceptor body surface being the shell surface of the rod-shaped susceptor body. For configurations in which the susceptor body is provided as a substantially planar element, a rod-shaped susceptor body precursor may be provided as a filament or strip, and a rod-shaped successor may be cut from the filament or strip to the desired dimensions. Of course, a susceptor device or intermediate product thereof may similarly be provided as a filament-like or strip-like precursor and processed accordingly.

[0030] The susceptor body may also include at least one fiber or thread; more preferably, the susceptor body or susceptor device may be provided as one of a wick, fleece, mesh, or woven fabric. These alternative configurations are particularly advantageous when the aerosol-forming substrate is provided as a liquid or gel-like substrate, and a susceptor body or susceptor device provided as one of a wick, fleece, mesh, or woven fabric may be used not only to heat the aerosol-forming substrate but also to store and / or transport the aerosol-forming substrate due to the capillary properties of the wick, fleece, mesh, or woven fabric. The susceptor body may be provided as a fiber, fiber bundle, or thread, after which a first heat spreading layer may be provided on the susceptor body, and then a wick, fleece, mesh, or woven fabric may be made from the susceptor body including the first heat spreading layer. Alternatively, the susceptor body may already be provided as one of a batt, fleece, mesh, or fabric, and then the first heat spreading layer may be provided on the susceptor body. Intermediate forms may also be possible. As an example, a fabric may be provided that includes a first susceptor material, a temperature marker layer having a specific Curie temperature, and a protective layer. The fabric may then be used to fabricate a susceptor body mesh, and then the first heat spreading layer may be provided on the susceptor body mesh.

[0031] Alternatively, the susceptor body or susceptor device may be a mesh. The difference from the above-mentioned configuration is that in this preferred configuration, the susceptor body does not include fibers or threads, but is monolithically formed as a mesh. As an example, the susceptor body may be provided as a multi-layer sheet, which may then be perforated to form the mesh, and then a heat spreading layer may be provided on the mesh. Or the susceptor device may be provided as a multi-layer sheet, which may then be perforated to form the mesh.

[0032] Preferably, the susceptor body may be a bead, and the susceptor body surface may be an outer surface of the bead. Therefore, the susceptor body may be provided as a bulk material, particularly having a spherical shape. The advantage of the susceptor body being a bead is that the susceptor devices are spread or dispersed within the aerosol-forming substrate, thus providing more uniform heating of the aerosol-forming substrate compared to configurations with substantially flat or rod-shaped susceptor devices.

[0033] Preferably, the first and / or second heat diffusion material may have a thermal conductivity at 25 degrees Celsius of more than 80 W / (m K), in particular more than 100 W / (m K), more particularly more than 200 W / (m K), preferably more than 350 W / (m K), more preferably more than 1000 W / (m K).

[0034] According to another aspect of the present invention, there is provided an inductively heatable aerosol-generating article comprising an aerosol-forming substrate and at least one susceptor device as described herein. As noted above, all preferred features and advantages associated with these preferred features may be applied to the inductively heatable aerosol-generating article.

[0035] As used herein, the term "aerosol-generating article" refers to an article comprising at least one aerosol-forming substrate capable of emitting a volatile compound capable of forming an aerosol when heated. The aerosol-generating article is preferably a heated aerosol-generating article, i.e., an aerosol-generating article comprising at least one aerosol-forming substrate intended to be heated rather than combusted. The aerosol-generating article may also be a consumable product, particularly one that is disposed of after a single use. For example, the article may be a cartridge containing a liquid aerosol-forming substrate to be heated. As another example, the article may be a rod-shaped article resembling a conventional cigarette, particularly a tobacco article.

[0036] As used herein, the term "aerosol-forming substrate" refers to a substrate formed from or containing an aerosol-forming material capable of releasing a volatile compound upon heating to generate an aerosol. Preferably, the aerosol-forming substrate is intended to be heated, rather than combusted, to release the aerosol-forming volatile compound. The aerosol-forming substrate may be a solid aerosol-forming substrate, a liquid aerosol-forming substrate, a gel-like aerosol-forming substrate, or any combination thereof. For example, the aerosol-forming substrate may contain both solid and liquid components. The aerosol-forming substrate may include a tobacco-containing material containing volatile tobacco flavor compounds that are released from the substrate upon heating. Alternatively, or additionally, the aerosol-forming substrate may include a non-tobacco material. The aerosol-forming substrate may further include an aerosol former. Examples of suitable aerosol formers are glycerin and propylene glycol. The aerosol-forming substrate may also include other additives and ingredients (such as nicotine or flavoring agents). The aerosol-forming substrate may also be a paste-like material, a sachet of porous material containing the aerosol-forming substrate, or, for example, loose tobacco mixed with a gelling or adhesive agent, which may include a common aerosol former such as glycerin, and compressed or molded into a plug.

[0037] Preferably, the article is an elongated or rod-shaped article. The elongated or rod-shaped article may have a shape that resembles the shape of a conventional cigarette.

[0038] Aerosol-generating articles, especially elongated or rod-shaped articles, may have a circular, elliptical, oval, square, rectangular, triangular or polygonal cross section.

[0039] As an example, the aerosol-generating article may be a rod-shaped article, in particular a cylindrical article comprising one or more of the following elements: a distal front plug element, a base element, a first tube element, a second tube element, and a filter element.

[0040] The substrate element preferably comprises at least one aerosol-forming substrate to be heated and a susceptor device in thermal contact or proximity with the aerosol-forming substrate. The substrate element may have a length of 10 to 14 millimeters, for example 12 millimeters.

[0041] The first tube element is distal to the second tube element. Preferably, the first tube element is proximal to the base element, and the second tube element is proximal to the first tube element and distal to the filter element, i.e., between the first tube element and the filter element. At least one of the first tube element and the second tube element may comprise a central air passage. The cross-section of the central air passage of the second tube element may be larger than the cross-section of the central air passage of the first tube element. Preferably, at least one of the first tube element and the second tube element may comprise a hollow cellulose acetate tube. At least one of the first tube element and the second tube element may have a length of 6 to 10 millimeters, for example, 8 millimeters.

[0042] The filter element preferably functions as a mouthpiece or as part of a mouthpiece together with a second tube element. As used herein, the term "mouthpiece" refers to the portion of the aerosol-generating article through which the aerosol exits the article. The filter element may have a length of 10 millimeters to 14 millimeters, for example, 12 millimeters.

[0043] The distal front plug element can be used to cover and protect the distal front end of the base element. The distal front plug element can have a length of 3 to 6 millimeters, for example, 5 millimeters. The distal front plug element can be made of the same material as the filter element.

[0044] All of the aforementioned elements may be disposed consecutively along the longitudinal axis of the article in the order described above, with the distal forward plug element preferably disposed at the distal end of the article and the filter element preferably disposed at the proximal end of the article. Each of the aforementioned elements may be substantially cylindrical. In particular, all of the elements may have the same external cross-sectional shape and / or dimensions. Additionally, the elements may be surrounded by one or more outer wrappers to hold the elements together and maintain the desired cross-sectional shape of the rod-shaped article, etc. The wrappers are preferably made of paper. The wrappers may further comprise an adhesive that bonds the overlapping free ends of the wrappers to each other. For example, the distal forward plug element, the base element, and the first tubing element may be surrounded by a first wrapper, and the second tubing element and the filter element may be surrounded by a second wrapper. The second wrapper may also surround at least a portion of the first tubing element (after being wrapped by the first wrapper) and connect the distal forward plug element, the base element, and the first tubing element, which are surrounded by the first wrapper, to the second tubing element and the filter element. The second wrapper may include perforations around its circumference.

[0045] According to another aspect of the present invention, there is provided an aerosol-generating apparatus for heating an aerosol-generating article comprising an aerosol-forming substrate, the aerosol-generating apparatus comprising at least one susceptor device as described herein. As noted above, all preferred features and advantages associated with these preferred features may be applied depending on the aerosol-generating apparatus.

[0046] The term "aerosol-generating device" as used herein may refer to an electrically operated device for interaction with an aerosol-generating article comprising an aerosol-forming substrate to generate an aerosol by inductively heating the aerosol-forming substrate via a susceptor device of the device. The aerosol-generating device is preferably a smoking device for generating an aerosol that can be directly inhaled by a user through the user's mouth. In particular, the aerosol-generating device is a handheld aerosol-generating device.

[0047] The device may comprise a receiving cavity for removably receiving at least a portion of the aerosol-generating article.

[0048] The aerosol generating device includes an induction heating device constructed and arranged to generate an alternating magnetic field capable of inductively heating a susceptor device of the device.

[0049] To generate the alternating magnetic field, the induction heating device may comprise at least one induction coil surrounding at least a portion of the susceptor device, which may be a helical coil or a flat planar coil, in particular a pancake coil or a curved planar coil.

[0050] The induction heating device may further comprise an alternating current (AC) generator. The AC generator may be powered by a power supply of the aerosol generating device. The AC generator is operably coupled to at least one induction coil. In particular, the at least one induction coil may be an integral part of the AC generator. The AC generator is configured to generate a high-frequency oscillating current that passes through the at least one induction coil to generate an alternating magnetic field. The AC current may be supplied to the at least one induction coil continuously after activation of the system, or may be supplied intermittently (e.g., after each puff). Preferably, the induction heating device comprises a DC / AC converter including an LC network, the LC network comprising a series connection of a capacitor and an inductor. The DC / AC converter may be connected to a DC power source.

[0051] The induction heating device is preferably configured to generate a high-frequency magnetic field. As referred to herein, the frequency of the high-frequency magnetic field may be an alternating magnetic field with a frequency in the range of 500 kHz (kilohertz) to 30 MHz (megahertz), particularly 5 MHz (megahertz) to 15 MHz (megahertz), and preferably 5 MHz (megahertz) to 10 MHz (megahertz).

[0052] The aerosol generating device may further comprise a controller configured to control the operation of the heating process, preferably in a closed loop configuration, in particular to control the heating of the aerosol-forming liquid to a predetermined operating temperature.

[0053] The controller may be the overall controller of the aerosol generating device or may be part of the overall controller of the aerosol generating device.

[0054] The controller may comprise a microprocessor (e.g., a programmable microprocessor), a microcontroller, or an application specific integrated circuit (ASIC) or other electronic circuit capable of providing control. The controller may comprise further electronic components, such as at least one DC / AC inverter and / or a power amplifier (e.g., a class C power amplifier, or a class D power amplifier, or a class E power amplifier). In particular, the inductive source may be part of the controller.

[0055] The aerosol generating device may also comprise a power supply, in particular a DC power supply configured to provide a DC supply voltage and a DC supply current to the induction source.

[0056] The power source is preferably a battery, such as a lithium iron phosphate battery. The power source may be rechargeable. The power source may have a capacity that allows for storage of sufficient energy for one or more user experiences. For example, the power source may have a capacity sufficient to allow continuous generation of aerosol for approximately six minutes, or a multiple of six minutes. In another embodiment, the power source may have a capacity sufficient to allow a predetermined number of puffs, or discontinuous operation of the induction source. [Example]

[0057] The present invention is defined in the claims. However, below is provided a non-exhaustive list of non-limiting examples. Any one or more of the features of these examples may be combined with any one or more features of any other example, embodiment, or aspect described herein.

[0058] Example 1: 1. A susceptor apparatus for inductively heating an aerosol-forming substrate, comprising: at least one susceptor body having a susceptor body surface and comprising a first susceptor material; and a first heat spreading layer comprising a first heat spreading material, the first heat spreading layer extending over at least a portion of the susceptor body surface and in thermal contact or thermal proximity with a portion of the susceptor body surface, the first heat spreading material having a thermal conductivity at least 3.5 times, preferably 4 times, and more preferably 5 times greater than the thermal conductivity of the first susceptor material. Example 2: 10. The susceptor device of claim 1, wherein the first heat spreading material is a carbon allotrope, preferably graphite or graphene. Example 3: 3. The susceptor apparatus of any one of claims 1 to 2, wherein the first heat spreading material is provided as a graphite sheet, preferably a pyrolytic graphite sheet. Example 4: The susceptor device of Example 3, wherein the graphite sheet has a thickness of 1 micrometer to 200 micrometers, preferably 5 micrometers to 20 micrometers, and more preferably substantially 10 micrometers. Example 5: 10. The susceptor device of claim 1, wherein the first heat spreading material is a metal. Example 6: 6. The susceptor device of example 5, wherein the metal is selected from the group consisting of copper, copper alloy, nickel, nickel alloy, aluminum, and aluminum alloy. Example 7: The susceptor device according to Example 5 or 6, wherein the first thermal diffusion layer has a thickness of 2 micrometers to 100 micrometers, preferably 3 micrometers to 60 micrometers, more preferably 5 micrometers to 20 micrometers, more preferably 12 micrometers to 16 micrometers, for example, 3 micrometers to 30 micrometers or 30 micrometers to 60 micrometers. Example 8: 8. The susceptor device according to any one of Examples 1 to 7, wherein the separation layer is disposed between the susceptor body and the first thermal diffusion layer. Example 9: 9. The susceptor device of example 8, wherein the isolation layer comprises at least one of an electrical insulating layer, a diffusion barrier layer, a temperature marker layer having a specific Curie temperature, and a protective layer. Example 10: The susceptor device according to any one of Examples 1 to 9, wherein the first thermal diffusion layer is at least partially coated with at least one of an electrical insulating layer, a diffusion prevention layer, a temperature marker layer having a specific Curie temperature, and a protective layer. Example 11: The susceptor apparatus of any one of Examples 1 to 10, wherein the susceptor body is a substantially planar element, and the susceptor body surface includes a first susceptor body major surface and an opposing second susceptor body major surface. Example 12: 12. The susceptor apparatus of example 11, wherein the first heat spreading layer extends across at least a portion of at least one of the first susceptor body major surface and the second susceptor body major surface. Example 13: A susceptor device as described in Example 11, wherein the first heat spreading layer extends over at least a portion of the first susceptor body main surface, and the susceptor device further comprises a second heat spreading layer comprising a second heat spreading material, the second heat spreading layer extending over at least a portion of the second susceptor body main surface and in thermal contact or thermal proximity with a portion of the second susceptor body main surface. Example 14: 14. The susceptor apparatus of example 13, wherein the first heat spreading layer extends across the entire first susceptor body major surface and / or the second heat spreading layer extends across the entire second susceptor body major surface. Example 15: A susceptor device as described in Example 13 or 14, wherein the first thermal diffusion layer and the second thermal diffusion layer are identical in at least one of the thermal diffusion material, the thickness of the thermal diffusion layer, the width of the thermal diffusion layer, the length of the thermal diffusion layer, and the area of ​​the thermal diffusion layer. Example 16: The susceptor device according to any one of Examples 11 to 15, wherein the susceptor body is a multi-layer susceptor body. Example 17: 17. The susceptor apparatus of example 16, wherein the susceptor body comprises at least two layers. Example 18: 18. The susceptor apparatus of example 17, wherein the susceptor body comprises a layer made of a first susceptor material and a temperature marker layer having a specific Curie temperature. Example 19: 19. The susceptor apparatus of example 18, wherein the susceptor body preferably further comprises a protective layer intimately coupled to the temperature marker layer. Example 20: The susceptor device according to any one of Examples 1 to 10, wherein the susceptor body is rod-shaped, and the susceptor body surface is a shell surface of the rod-shaped susceptor body. Example 21: 11. The susceptor device according to any one of Examples 1 to 10, wherein the susceptor body comprises at least one fiber or strand. Example 22: 22. The susceptor device of example 21, wherein the susceptor body or susceptor device is provided as one of a wick, a fleece, a mesh, or a woven fabric. Example 23: The susceptor device according to any one of Examples 1 to 10, wherein the susceptor body or the susceptor device is a mesh. Example 24: The susceptor device according to any one of Examples 1 to 10, wherein the susceptor body is a bead, and the susceptor body surface is an outer surface of the bead. Example 25: The susceptor device according to any one of Examples 1 to 24, wherein the first thermal diffusion material and / or the second thermal diffusion material has a thermal conductivity greater than 80 W / (m K), in particular greater than 100 W / (m K), more particularly greater than 200 W / (m K), preferably greater than 350 W / (m K), and more preferably greater than 1000 W / (m K). Example 26: An inductively heatable aerosol-generating article comprising an aerosol-forming substrate and at least one susceptor device according to any one of Examples 1 to 25. Example 27: 26. An aerosol-generating apparatus for heating an aerosol-generating article comprising an aerosol-forming substrate, the aerosol-generating apparatus comprising at least one susceptor device according to any one of Examples 1 to 25.

[0059] The embodiments will now be further described with reference to the figures. [Brief explanation of the drawings]

[0060] [Figure 1] Figure 1A shows a schematic representation of a possible configuration of a susceptor body without a heat spreading layer, and Figures 1B-C show a schematic representation of a possible configuration of a susceptor body and heat spreading layer according to the present invention. [Figure 2] Figure 2A shows a schematic representation of a possible configuration of a susceptor body without a heat spreading layer, and Figures 2B-C show a schematic representation of different possible layer configurations of a susceptor device according to the present invention. [Figure 3] 3A-B show, in schematic cross-sectional views, further possible layer configurations of a susceptor device according to the present invention. [Figure 4] FIG. 4 shows a schematic cross section through a rod-shaped susceptor device according to the present invention. [Figure 5] FIG. 5 shows a schematic representation of an inductively heatable aerosol-generating article comprising a susceptor device according to the present invention. [Figure 6] FIG. 6 shows a schematic diagram of an aerosol generating device comprising an aerosol-generating article according to the present invention. [Figure 7] FIG. 7 shows a schematic diagram of an aerosol generating device comprising a susceptor device according to the present invention. [Figure 8] FIG. 8 shows a schematic diagram of another embodiment of an aerosol generating device comprising a susceptor device according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0061] 1A shows a susceptor body 2 provided as a substantially planar element. The susceptor body 2 has a susceptor body surface 3, which in the configuration shown in FIG. 1A comprises a first susceptor body major surface 3′ and a second susceptor body major surface 3″ opposite the first susceptor body major surface 3′.

[0062] 1B shows a susceptor apparatus including the susceptor body 2 shown in FIG. 1A and a first heat spreading layer 4. The first heat spreading layer 4 is in thermal contact with or in thermal proximity to the first susceptor body main surface 3′ and extends substantially across the entire first susceptor body main surface 3′. In contrast, the second susceptor body main surface 3″ opposite the first susceptor body main surface 3′ is not covered by any layer, in particular a heat spreading layer, but is exposed.

[0063] In FIG. 1C , the susceptor device 1 includes a first heat spreading layer 4 and a second heat spreading layer 5. The first heat spreading layer 4 is in thermal contact with or close to the first susceptor body major surface 3′ and extends substantially across the entire first susceptor body major surface 3′, and the second heat spreading layer 5 is in thermal contact with or close to the second susceptor body major surface 3″ and extends substantially across the entire second susceptor body major surface 3″. The first heat spreading layer 4 and / or the second heat spreading layer 5 improve the distribution and dispersion of heat generated across the surface of the susceptor device 1, thus enabling a more uniform temperature distribution across the surface of the susceptor device 1 while avoiding temperature hot spots on the surface of the susceptor device 1. This improves heating of the aerosol-generating substrate, and a uniform temperature distribution across the aerosol-generating substrate is achieved.

[0064] In FIG. 2A , another possible configuration of the susceptor body 2 is shown in cross section. The susceptor body 2 is a multi-layer susceptor body comprising a layer made of a first susceptor material 6 intimately bonded to a temperature marker layer 7. The susceptor body 2 also comprises a protective layer 8 intimately bonded to the temperature marker layer 7 opposite the layer made of the first susceptor material 6. The first susceptor body major surface 3′ is the outer surface of the layer made of the first susceptor material 6, while the second susceptor body major surface 3″ is the outer surface of the protective layer 8. The first susceptor material 6 is steel, specifically AISI 430 steel, and has a thickness of 40.5 micrometers. The temperature marker layer 7 is made of an FeNi80Mo alloy and has a thickness of 16.5 micrometers. The protective layer 8 is made of steel, specifically AISI 430 steel, and has a thickness of 3 micrometers. In an alternative configuration, the temperature marker layer 7 is made of an FeNi80Mo alloy and has a thickness of 16 micrometers, while the protective layer 8 is made of steel, in particular AISI 430 steel, and has a thickness of 3.5 micrometers.

[0065] 2B and 2C show another possible configuration of the susceptor apparatus 1. The susceptor body 2 is shown in the same configuration as the susceptor body 2 in FIG. 2A for simplicity's sake only. The first susceptor body major surface 3' and the second susceptor body major surface 3'' are provided with a first heat spreading layer 4 and a second heat spreading layer 5, respectively. The first heat spreading layer 4 and the second heat spreading layer 5 comprise a first heat spreading material and a second heat spreading material, respectively.

[0066] In the configuration of FIG. 2C, the first heat spreading layer 4 and the second heat spreading layer 5 are in thermal contact with the susceptor body 2, while in the configuration of FIG. 2B, separation layers 9 are interposed between the susceptor body 2 and the first heat spreading layer 4 and between the susceptor body 2 and the second heat spreading layer 5, respectively. Each of the two separation layers 9 is an electrical insulator layer having a thickness of 5 micrometers. The first heat spreading material and / or the second heat spreading material may be a carbon allotrope such as graphite. The first heat spreading layer 4 and the second heat spreading layer 5 may each have a thickness of 10 micrometers. The graphite is preferably provided as a graphite sheet and is bonded to the susceptor body 2 as shown in FIG. 2C or to the respective separation layers 9 as shown in FIG. 2B by an adhesive.

[0067] Alternatively, the first heat spreading material and / or the second heat spreading material may be another carbon allotrope, such as graphene. Graphene may be deposited on the susceptor body 2 as shown in FIG. 2C or on the separation layer 9 as shown in FIG. 2B by a vapor deposition method, preferably a chemical vapor deposition (CVD) method or a catalytic chemical vapor deposition (CCVD) method. The first heat spreading layer 4 and / or the second heat spreading layer 5 may each include one graphene layer or several graphene layers.

[0068] In another alternative configuration, the first heat spreading material and / or the second heat spreading material is a metal or metal alloy.

[0069] Another possible configuration of the susceptor device 1 is shown in FIG. 3A. The susceptor device 1 includes a susceptor body 2 including a first susceptor material 6 having a first susceptor body major surface 3' and a second susceptor body major surface 3''. The first susceptor material 6 is steel, particularly AISI 430 steel. The susceptor body 2 can have a thickness of up to 60 micrometers. A first heat spreading layer 4 is in thermal contact with the first susceptor body major surface 3' and has a thickness of 12 to 16 micrometers. The first heat spreading layer 4 is intimately bonded to the susceptor body 2 and includes at least a first heat spreading material, preferably a carbon allotrope or a metal, as described above. Alternatively, as shown in FIG. 3B, a separation layer 9 is disposed between the susceptor body 2 and the first heat spreading layer 4. The separation layer 9 is made of a diffusion barrier material and has a thickness of 6 micrometers. The susceptor device 1 further includes a temperature marker layer 7 that is tightly bonded to the first heat spreading layer 4 facing the susceptor body 2. The temperature marker layer 7 is made of an FeNi80Mo alloy and has a thickness of 6 to 8 micrometers. The susceptor device 1 further includes a protective layer 8 that is tightly bonded to the temperature marker layer 7. The protective layer 8 is made of steel, in particular, AISI430 steel, and has a thickness of 3.5 micrometers.

[0070] FIG. 4 shows a schematic cross section through a rod-shaped susceptor device 1. The rod-shaped susceptor device 1 comprises a multi-layer rod-shaped susceptor body 2 having a susceptor body surface 3, which is the shell surface of the rod-shaped susceptor body 2. The multi-layer rod-shaped susceptor body 2 comprises a core comprising a first susceptor material 6. On top, the rod-shaped susceptor body 2 further comprises a temperature marker layer 7 intimately bonded to the core comprising the first susceptor material 6. On top of the temperature marker layer 7, the rod-shaped susceptor body 2 further comprises a protective layer 8 intimately bonded to the temperature marker layer 7. The susceptor device 1 further comprises a first heat spreading layer 4 intimately bonded to the protective layer 8 of the susceptor body 2, which in this configuration forms the susceptor body surface 3.

[0071] It should be self-explanatory that in the case of a rod-shaped susceptor device 1, the configurations described above are purely exemplary and that other configurations than those described above for a susceptor body 2 provided as a substantially flat element can be implemented.

[0072] 5 is a schematic diagram of an inductively heatable aerosol-generating article 10 (not drawn to scale) comprising a susceptor device 1 according to the present invention. The aerosol-generating article 10 is a substantially rod-shaped consumable comprising five elements arranged consecutively in coaxial alignment: a distal forward plug element 11, a base element 12, a first tube element 13, a second tube element 14, and a filter element 15. The distal forward plug element 11 is disposed at a distal end 16 of the aerosol-generating article 10 and covers and protects the distal forward end of the base element 12, while the filter element 15 is disposed at a proximal end 17 of the aerosol-generating article 10. Both the distal forward plug element 11 and the filter element 15 may be made of the same filter material. The filter element 15 preferably functions as a mouthpiece, preferably as part of the mouthpiece together with the second tube element 14.

[0073] The filter element 15 may have a length of 10 to 14 millimeters, e.g., 12 millimeters, while the distal front plug element 11 may have a length of 3 to 6 millimeters, e.g., 5 millimeters. The base element 12 comprises a heated aerosol-forming substrate 18 and a susceptor device 1 according to the present invention, as shown in Figures 1B, 1C; 2B, 2C, 3A, or 3B, configured and arranged to heat the aerosol-forming substrate 18. To this end, the susceptor device 1 is fully embedded in the aerosol-forming substrate 18, e.g., to be in direct thermal contact with the aerosol-forming substrate 18. The base element 12 may have a length of 10 to 14 millimeters, e.g., 12 millimeters. Each one of the first and second pipe elements 13, 14 is a hollow cellulose acetate tube having a central air passage 19, 20, while the cross section of the central air passage 20 of the second pipe element 14 is larger than the cross section of the central air passage 19 of the first pipe element 13. The first pipe element 13 and the second pipe element 14 may have a length of 6 mm to 10 mm, for example 8 mm.

[0074] In use, an aerosol formed by volatile compounds released from the substrate element 12 is drawn through the first and second tube elements 13, 14, and the filter element 15 toward the proximal end 17 of the aerosol-generating article 10. Each of the aforementioned elements 11, 12, 13, 14, and 15 may be substantially cylindrical. In particular, all elements 11, 12, 13, 14, and 15 may have the same external cross-sectional shape and dimensions.

[0075] Additionally, the elements may be surrounded by one or more outer wrappers to hold the elements together, maintain the desired cross-sectional shape of the rod-shaped article, etc. The distal forward plug element 11, the base element 12, and the first tube element 13 are surrounded by a first wrapper 21, while the second tube element 14 and the filter element 15 are surrounded by a second wrapper 22. The second wrapper 22 also surrounds at least a portion of the first tube element 13 (after being wrapped by the first wrapper 21) and connects the distal forward plug element 11, the base element 12, and the first tube element 13, which are surrounded by the first wrapper 21, to the second tube element 14 and the filter element 15. The first wrapper 21 and the second wrapper 22 are preferably made of paper. Additionally, the second wrapper 22 may include perforations (not shown) around its periphery. The wrappers 21, 22 may further include an adhesive that adheres the overlapping free ends of the wrappers to each other.

[0076] As shown in Figure 6, the aerosol-generating article 10 according to Figure 5 is configured for use in an induction-heated aerosol-generating device 23. The aerosol-generating device 23 and the aerosol-generating article 10 together form an aerosol-generation system 24. The aerosol-generating device 23 comprises a cylindrical receiving cavity 25 defined in a proximal portion 26 of the aerosol-generating device 23 for receiving at least a distal portion of the aerosol-generating article 10 therein. The aerosol-generating device 23 further comprises an induction-heating device including an induction coil 27 for generating an alternating magnetic field, in particular a high-frequency alternating magnetic field, within the cylindrical receiving cavity 25. The induction coil 27 is a helical coil that circumferentially surrounds the cylindrical receiving cavity 25. The induction coil 27 is arranged so that the susceptor device 1 of the aerosol-generating article 10 is exposed to the magnetic field upon insertion of the aerosol-generating article 10 into the cylindrical receiving cavity 25 of the aerosol-generating device 23. Therefore, when the induction heating device is operated, the susceptor device 1 heats up due to eddy currents and / or hysteresis losses induced by the alternating magnetic field, depending on the magnetic and electrical properties of the susceptor material of the susceptor device 1. The susceptor device 1 is heated until it reaches an operating temperature sufficient to vaporize the aerosol-forming substrate 18 surrounding the susceptor device 1 within the aerosol-generating article 10. Within the distal portion 28, the aerosol-generating device 23 further comprises a DC power supply 29 and a controller 30 (shown only diagrammatically in FIG. 6 ) for powering and controlling the heating process. Apart from the induction coil 27, the induction heating device is preferably an at least partially integral part of the controller 30.

[0077] FIG. 7 illustrates an aerosol-generating device 23′ according to the present invention, which includes a susceptor device 1. The aerosol-generating device 23′ is configured for use with an aerosol-generating article 10′. The aerosol-generating article 10′ is configured substantially similar to the aerosol-generating article 10 shown in FIG. 5, but lacks the susceptor device 1. The aerosol-generating device 23′ and the aerosol-generating article 10′ together form an aerosol-generating system 24′. The aerosol-generating device 23′ includes a cylindrical receiving cavity 25′ defined in a proximal portion 26′ of the aerosol-generating device 23′ for receiving at least a distal portion of the aerosol-generating article 10′ therein. The aerosol-generating device 23′ further includes an induction heating device including an induction coil 27′ for generating an alternating magnetic field, particularly a high-frequency alternating magnetic field, within the cylindrical receiving cavity 25′. The induction coil 27′ is a helical coil circumferentially surrounding the cylindrical receiving cavity 25′. The susceptor device 1 is provided as a substantially cylindrical hollow body within and coaxial with the cylindrical receiving cavity 25'. In this configuration, the susceptor device 1 implements an induction heating oven or heating chamber. The susceptor device 1 is disposed so as to at least partially surround the substrate element 12 of the aerosol-generating article 10' when the aerosol-generating article 10' is inserted into the cylindrical receiving cavity 25', as shown in FIG.

[0078] The susceptor device 1 is further disposed so as to be exposed to a magnetic field generated by an induction heating device of the aerosol-generating device 23'. Therefore, when the induction heating device is activated, the susceptor device 1 heats up due to eddy currents and / or hysteresis losses induced by the alternating magnetic field, depending on the magnetic and electrical properties of the susceptor material of the susceptor device 1. The susceptor device 1 is heated until it reaches an operating temperature sufficient to vaporize the aerosol-forming substrate 18 within the aerosol-generating article 10. Within the distal portion 28', the aerosol-generating device 23' further comprises a DC power supply 29' and a controller 30' (shown only diagrammatically in FIG. 7) for powering and controlling the heating process. Apart from the induction coil 27', the induction heating device is preferably an at least partially integral part of the controller 30'.

[0079] FIG. 8 shows another embodiment of an aerosol-generating device 23'' comprising a susceptor device 1 according to the present invention. The aerosol-generating device 23'' is configured for use with an aerosol-generating article 10''. The aerosol-generating article 10'' is configured substantially similar to the aerosol-generating article 10 shown in FIG. 5, but lacks the susceptor device 1 and the distal front plug element 11. Instead, the base element 12 has an extension of greater length.

[0080] The aerosol-generating device 23'' comprises a cylindrical receiving cavity 25'' defined in a proximal portion 26'' of the aerosol-generating device 23'' for receiving at least a distal portion of the aerosol-generating article 10'' therein. The aerosol-generating device 23'' further comprises an induction heating device including an induction coil 27'' for generating an alternating magnetic field, in particular a high-frequency alternating magnetic field, within the cylindrical receiving cavity 25''. The induction coil 27'' is a helical coil circumferentially surrounding the cylindrical receiving cavity 25''. The susceptor device 1 is provided as a blade element, a rod element, or a pin element and is disposed within the cylindrical receiving cavity 25''.

[0081] The distal end of the susceptor device 1 is disposed in the bottom portion of the cylindrical receiving cavity 25''. From there, the susceptor device 1 extends into the interior space of the cylindrical receiving cavity 25'' toward an opening of the cylindrical receiving cavity 25'' located in the proximal portion 26'' of the aerosol-generating device 23''. The proximal end of the susceptor device 1 may be tapered, pointed, or provided with a sharp edge for easily penetrating the substrate element 12 of the aerosol-generating article 10'' at the distal end 16 of the aerosol-generating article 10'' when the aerosol-generating article 10'' is inserted into the cylindrical receiving cavity 25'', as shown in FIG. 8 .

[0082] The susceptor device 1 is disposed so as to be exposed to a magnetic field generated by an induction heating device of the aerosol-generating device 23''. Therefore, when the induction heating device is operated, the susceptor device 1 heats up due to eddy currents and / or hysteresis losses induced by the alternating magnetic field, depending on the magnetic and electrical properties of the susceptor material of the susceptor device 1. The susceptor device 1 is heated until it reaches an operating temperature sufficient to vaporize the aerosol-forming substrate 18 in the aerosol-generating article 10''. Within the distal portion 28'' the aerosol-generating device 23'' further comprises a DC power supply 29'' and a controller 30'' (shown only diagrammatically in FIG. 8) for powering and controlling the heating process. Apart from the induction coil 27'', the induction heating device is preferably an at least partially integral part of the controller 30''.

[0083] For purposes of this specification and the appended claims, unless otherwise indicated, all numbers expressing amounts, quantities, percentages, and the like are understood to be modified in all instances by the term "about." Also, all ranges include the disclosed maximum and minimum points, and include any intermediate ranges therein, which may or may not be specifically recited herein. Thus, in this context, a numerical value A is understood as A ± 5% for A. In this context, a numerical value A can be considered to include values ​​that fall within the usual standard error of measurement for the property that A modifies. In some instances, as used in the appended claims, a numerical value A may deviate by the percentages recited above, so long as the amount by which A deviates does not materially affect the basic and novel characteristics of the claimed invention. Also, all ranges include the disclosed maximum and minimum points, and include any intermediate ranges therein, which may or may not be specifically recited herein.

Claims

1. 1. A susceptor apparatus for inductively heating an aerosol-forming substrate, comprising: - at least one susceptor body having a susceptor body surface and comprising a first susceptor material; a first heat spreading layer comprising a first heat spreading material; Equipped with the first heat spreading layer extends over at least a portion of the susceptor body surface and in thermal contact or proximity with said portion of the susceptor body surface, and the first heat spreading material is a non-magnetic metal or non-magnetic metal alloy having a thermal conductivity at least 3.5 times, preferably 4 times, and more preferably 5 times greater than the thermal conductivity of the first susceptor material; Susceptor device.

2. The susceptor device of claim 1 , wherein the metal is selected from the group consisting of copper, copper alloys, aluminum, and aluminum alloys.

3. 3. The susceptor device according to claim 1, wherein the first heat spreading layer has a thickness of 2 micrometers to 100 micrometers, preferably 3 micrometers to 60 micrometers, more preferably 5 micrometers to 20 micrometers, in particular 12 micrometers to 16 micrometers, for example 3 micrometers to 30 micrometers or 30 micrometers to 60 micrometers.

4. 4. The susceptor device according to claim 1, wherein a separation layer is disposed between the susceptor body and the first thermal diffusion layer.

5. The susceptor device of claim 4 , wherein the isolation layer includes at least one of an electrical insulating layer, a diffusion barrier layer, a temperature marker layer having a specific Curie temperature, and a protective layer.

6. 6. The susceptor apparatus of claim 1, wherein the susceptor body is a substantially flat element, and the susceptor body surface comprises a first susceptor body major surface and an opposing second susceptor body major surface.

7. 7. The susceptor device of claim 6, wherein the first heat spreading layer extends over at least a portion of the first susceptor body major surface, and the susceptor device further comprises a second heat spreading layer comprising a second heat spreading material, the second heat spreading layer extending over at least a portion of the second susceptor body major surface and in thermal contact or thermal proximity with the portion of the second susceptor body major surface.

8. The susceptor apparatus of claim 7 , wherein the first heat spreading layer extends across the entire first susceptor body major surface and / or the second heat spreading layer extends across the entire second susceptor body major surface.

9. The susceptor device according to any one of claims 6 to 8, wherein the susceptor body is a multi-layer susceptor body.

10. 1. A susceptor apparatus for inductively heating an aerosol-forming substrate, comprising: at least one susceptor body having a susceptor body surface, said susceptor body being a substantially planar element, said susceptor body surface comprising a first susceptor body major surface and an opposing second susceptor body major surface, said susceptor body comprising a first susceptor material; a first heat spreading layer comprising a first heat spreading material; Equipped with the first heat spreading layer extends over at least a portion of the susceptor body surface and in thermal contact or thermal proximity with said portion of the susceptor body surface, the first heat spreading material is a metal having a thermal conductivity at least 3.5 times, preferably 4 times, more preferably 5 times greater than the thermal conductivity of the first susceptor material, and the first heat spreading layer is at least partially coated with a temperature marker layer having a specific Curie temperature; Susceptor device.

11. The susceptor device of claim 1 , wherein the metal is selected from the group consisting of copper, copper alloys, nickel, nickel alloys, aluminum, and aluminum alloys.

12. 12. The susceptor device according to claim 10 or 11, wherein the first heat spreading layer has a thickness of 2 micrometers to 100 micrometers, preferably 3 micrometers to 60 micrometers, more preferably 5 micrometers to 20 micrometers, in particular 12 micrometers to 16 micrometers, for example 3 micrometers to 30 micrometers or 30 micrometers to 60 micrometers.

13. The susceptor device according to any one of claims 10 to 12, wherein a separation layer is disposed between the susceptor body and the first heat spreading layer.

14. 11. The susceptor device of claim 10, wherein the first heat spreading layer extends over at least a portion of the first susceptor body major surface, and the susceptor device further comprises a second heat spreading layer comprising a second heat spreading material, the second heat spreading layer extending over at least a portion of the second susceptor body major surface and in thermal contact or thermal proximity with the portion of the second susceptor body major surface.

15. The susceptor apparatus of claim 14 , wherein the first heat spreading layer extends across the entire first susceptor body major surface and / or the second heat spreading layer extends across the entire second susceptor body major surface.

16. The susceptor device according to any one of claims 10 to 15, wherein the susceptor body is a multi-layer susceptor body.

17. 1. A susceptor apparatus for inductively heating an aerosol-forming substrate, comprising: - at least one susceptor body having a susceptor body surface and comprising a first susceptor material; a first heat spreading layer comprising a first heat spreading material; Equipped with the first heat spreading layer extends over at least a portion of the susceptor body surface and in thermal contact or thermal proximity with said portion of the susceptor body surface, the first heat spreading material having a thermal conductivity at least 3.5 times, preferably 4 times, more preferably 5 times greater than the thermal conductivity of the first susceptor material, and the first heat spreading material is a carbon allotrope, preferably graphite or graphene; Susceptor device.

18. 18. The susceptor device of claim 17, wherein the first heat spreading material is provided as a graphite sheet, preferably a pyrolytic graphite sheet.

19. 19. The susceptor device of claim 18, wherein the graphite sheet has a thickness of 1 micrometer to 200 micrometers, preferably 5 micrometers to 20 micrometers, more preferably substantially 10 micrometers.

20. The susceptor device according to any one of claims 17 to 19, wherein a separation layer is disposed between the susceptor body and the first heat spreading layer.

21. 21. The susceptor device of claim 20, wherein the isolation layer comprises at least one of an electrical insulating layer, a diffusion barrier layer, a temperature marker layer having a specific Curie temperature, and a protective layer.

22. 22. The susceptor apparatus of claim 17, wherein the susceptor body is a substantially flat element, and the susceptor body surface comprises a first susceptor body major surface and an opposing second susceptor body major surface.

23. 23. The susceptor apparatus of claim 22, wherein the first heat spreading layer extends over at least a portion of the first susceptor body major surface, and the susceptor apparatus further comprises a second heat spreading layer comprising a second heat spreading material, the second heat spreading layer extending over at least a portion of the second susceptor body major surface and in thermal contact or thermal proximity with the portion of the second susceptor body major surface.

24. 24. The susceptor apparatus of claim 23, wherein the first heat spreading layer extends across the entire first susceptor body major surface and / or the second heat spreading layer extends across the entire second susceptor body major surface.

25. The susceptor device according to any one of claims 22 to 24, wherein the susceptor body is a multi-layer susceptor body.

26. 26. The susceptor device according to any one of claims 1 to 25, wherein the first and / or second heat spreading material has a thermal conductivity greater than 80 W / (m K), in particular greater than 100 W / (m K), more particularly greater than 200 W / (m K), preferably greater than 350 W / (m K), more preferably greater than 1000 W / (m K).

27. An inductively heatable aerosol-generating article comprising an aerosol-forming substrate and at least one susceptor device according to any one of claims 1 to 26.

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