Susceptor arrangement for heating an aerosol-forming substrate

Abstract

There is provided a susceptor arrangement for inductively heating an aerosol-forming substrate, comprising an elongate susceptor body configured to generate heat by absorbing energy from a magnetic field; at least one thermally conductive heat-spreading body being made from a different material as compared to the susceptor body and configured to spread the heat generated by the susceptor body across the aerosol-forming substrate, wherein the heat- spreading body extends along the elongate susceptor body and forms at least one wing that laterally protrudes beyond the susceptor body.

Description

[0001] Susceptor arrangement for heating an aerosol-forming substrate

[0002] 1. Technical field

[0003] The present disclosure relates to a susceptor arrangement for heating an aerosol-forming substrate. The invention further relates to a heatable aerosol-generating article comprising such a susceptor arrangement.

[0004] 2. Background

[0005] Aerosol-generating articles including at least one aerosol-forming substrate that is capable to form an inhalable aerosol when heated are generally known. For heating the aerosol-forming substrate, the aerosol-generating article may be received within an aerosolgenerating device, which comprises an electrical heater. The heater may be an inductive heater comprising an induction source. The induction source is configured for generating an alternating magnetic field to inductively heat a susceptor arrangement by at least one of eddy currents and hysteresis losses, depending on the electrical and magnetic properties of the susceptor arrangement. The susceptor arrangement may be an integral part of the aerosol-generating article and arranged such as to be in thermal proximity or direct physical contact with the aerosolgenerating substrate to be heated. In operation of the device, volatile compounds are released from the heated aerosol-forming substrate in the aerosol-generating article and entrained in an airflow that is drawn through the aerosol-generating article during a user's puff. As the released compounds cool down, they condense to form an aerosol.

[0006] To assure proper heating of the aerosol-forming substrate by the susceptor arrangement, the susceptor material requires suitable magnetic and electric properties and a certain thermal conductivity. In the prior art, the preferred material for the susceptor is steel, in particular AISI 430 steel. This material is a stainless steel, which avoids contamination of the aerosol-forming substrate with harmful substances typically resulting from degradation / corrosion of corrosive materials. The aerosol-generating article is disposable. With the susceptor arrangement being an integral part of the aerosol-generating article, the susceptor arrangement is used only once. This results in high material costs for the susceptor arrangement and a high cost-value-factor per aerosol-generating article.

[0007] Therefore, it would be desirable to have a susceptor arrangement with the advantages of prior art solutions, whilst reducing costs for the susceptor material. In particular, it would be desirable to achieve a volume reduction of the susceptor arrangement.

[0008] 3. Summary According to an aspect of the present invention, there is provided a susceptor arrangement for inductively heating an aerosol-forming substrate, comprising an elongate susceptor body configured to generate heat by absorbing energy from a magnetic field; at least one thermally conductive heat-spreading body being made from a different material as compared to the susceptor body and configured to spread the heat generated by the susceptor body across the aerosol-forming substrate, wherein the heat-spreading body extends along the elongate susceptor body and forms at least one wing that laterally protrudes beyond the susceptor body.

[0009] Using a susceptor arrangement wherein the heat-spreading body extends along the elongate susceptor body provides a plurality of advantages as compared to other susceptor arrangements. Most notably, the susceptor arrangement disclosed herein uses two separate bodies to provide the functionalities of heat generation on the one hand and heat distribution on the other hand, hitherto provided by the susceptor body itself. The susceptor body disclosed herein - in particular due to its elongate shape and energy absorbing material - is specifically designed and optimized to generate heat from a magnetic field. On the other hand, the heatspreading body is specifically designed and optimized to receive the heat generated by the susceptor body and dissipate it across the aerosol-generating article. The parallel arrangement of the heat-spreading body and the susceptor body enables a high heat transfer rate between the two bodies. The at least one laterally protruding wing of the heat-spreading body conveys the heat even to remote and peripheral areas of the aerosol-generating article, thereby allowing for a homogenous temperature distribution across the aerosol-generating article. In summary, the susceptor arrangement disclosed herein allows the susceptor body to be minimized so that it has considerably less width and volume as compared to conventional susceptor arrangements. Hence, the material costs for the susceptor material can be reduced. Hence, heating of the aerosol-generating substrate is improved while a low cost-factor per aerosol-generating article can be achieved.

[0010] Arrangement

[0011] The elongate susceptor body may extend along a first direction, wherein the first direction is the longitudinal direction of the susceptor arrangement. The longitudinal direction of the susceptor arrangement may coincide with the longitudinal direction of the aerosol-generating article. Hence, the elongate susceptor body may extend coaxially to the aerosol-generating article.

[0012] The elongate susceptor body and / or the heat-spreading body may have its maximum extension (length) in the first direction. The elongate susceptor body and / or heat-spreading body may extend over the entire length of the aerosol-generating article in the first direction.

[0013] The elongate susceptor body and the heat-spreading body may have the same extension in the first direction. This provides a homogenous heat distribution along the first direction. The at least one wing may protrude beyond the susceptor body in a second direction, which is different from the first direction, wherein the second direction may be the transversal direction. The second direction may be orthogonal to the first direction.

[0014] The susceptor body and / or the heat-spreading body may have its maximum width (not length) in the second direction. The susceptor body and / or the heat-spreading body may have a constant extension in the second direction over its entire extension in the first direction. The heatspreading body may have a greater extension than the susceptor body in the second direction. This arrangement may lead to a further reduction of the susceptor material and cost savings.

[0015] The relation of an extension of the heat-spreading body to an extension of the susceptor body in the second direction may be between 4 / 3 and 5 / 2. Thus, with this relation, sufficient inductive heating of the susceptor body and proper heat spreading by the heat-spreading body can be assured, while the susceptor material costs can be lowered.

[0016] Shape & Dimensions

[0017] The at least one wing may extend in a plane, wherein the plane may be spanned by the first direction and the second direction. The entire susceptor body may extend in the same or parallel plane and / or the entire heat-spreading body may extend in the same or parallel plane. Respective arrangement may provide simple manufacturing of the susceptor arrangement and may lead to homogeneous heat spreading within the aerosol-generating article.

[0018] The heat-spreading body may comprise two or more wings protruding beyond the susceptor body, wherein the wings may extend in the same plane. The wings may be symmetrically arranged to each other. The wings may protrude beyond different sides of the susceptor body. The wings may protrude beyond lateral sides of the susceptor body or may protrude beyond opposite sides of the susceptor body.

[0019] The susceptor body may have a self-supporting structure or may form a frame or skeleton. With this arrangement, the susceptor body can support the heat-spreading body. The susceptor body may comprise a backbone and limbs protruding from the backbone, wherein the wing may extend between the limbs of the susceptor body.

[0020] A volume and / or a surface area of the susceptor body may be less than that of the heatspreading body. This arrangement may lead to reduction of the susceptor material and cost savings.

[0021] The heat-spreading body may comprise at least one foil or strip. The heat-spreading body may be flexible and may extend in one plane. The heat-spreading body may have a polygonal outline. Preferably, the heat-spreading body has a rectangular outline, wherein the longer side may be aligned with the longitudinal or first direction and the shorter side may be aligned with the transversal or second direction. The heat-spreading body may have a thickness of 2 to 180 pm, preferably 3 to 100 pm, more preferred 5 to 100 pm, in particular 12 to 60 pm, for example 3 to 30 pm or 30 pm to 60 pm.

[0022] The heat-spreading body may partly or fully cover the susceptor body. Thus, the susceptor body and the heat-spreading body may be in direct contact with each other, providing maximum heat transfer via heat conduction. The heat transfer between the susceptor body and the heatspreading body may even be increased by pressing the bodies against each other.

[0023] The susceptor body may be partly or fully located inside the heat-spreading body and the susceptor body may be partly or fully embedded within the heat-spreading body. This arrangement may avoid direct contact between the susceptor body and the aerosol-generating substrate leading to less contamination of the aerosol-forming substrate with substances of the susceptor body.

[0024] The susceptor body may be partly or fully sandwiched between two layers of the heatspreading body. This may lead to permanent contact between the susceptor body and the heatspreading body, providing maximum heat transfer via heat conduction, while the susceptor body does not require further fixture to the heat-spreading body.

[0025] The heat-spreading body may be partly or fully folded around the susceptor body or the heat-spreading body may be partly or fully wrapped around the susceptor body. Such an arrangement may provide a simple manufacturing, and may provide a permanent contact between the susceptor body and the heat-spreading body with a maximum heat transfer via heat conduction.

[0026] The susceptor body may be centrally arranged in a transversal direction along a longitudinal direction of the susceptor arrangement. Such an arrangement may support controllable inductive heating as the alternating magnetic field can be arranged appropriately corresponding to the central arrangement of the susceptor in the aerosol-generating article.

[0027] The susceptor body and the heat-spreading body may be concentrically arranged with respect to the susceptor arrangement. The heat-spreading body may be symmetrically arranged with respect to the susceptor body, or vice-versa. Symmetrical arrangement of the susceptor body and the heat-spreading body may provide homogeneous spreading of the heat within the susceptor arrangement.

[0028] The susceptor body and the heat-spreading body may be provided laterally and / or longitudinally offset from one another. Laterally offset means that, as seen in topview (on the plane of extension), the susceptor body and the heat-spreading body are not symmetrically arranged with respect to a longitudinal direction of the susceptor arrangement. Longitudinally offset means that, as seen in topview (on the plane of extension), the susceptor body and the heat-spreading body are not symmetrically arranged with respect to a lateral direction of the susceptor arrangement. The lateral direction is orthogonal to the longitudinal direction of the susceptor arrangement. An offset arrangement of the susceptor body and the heat-spreading body may provide a higher overall surface of the susceptor body facing the aerosol-forming substrate and spread the heat within the aerosol-forming substrate so as to increase to aerosol yield and enhance the consumer experience.

[0029] The susceptor body may have a flat or plane shape or may have the shape of a layer or panel. This may provide simple manufacturing of the susceptor body.

[0030] The susceptor body may extend in one plane. The susceptor body may have a polygonal outline. The susceptor body may have a rectangular outline, wherein the longer side may be aligned with the longitudinal direction and wherein the shorter side may be aligned with the transversal direction. The shorter side of the susceptor body may be shorter than the shorter side of the heat-spreading body. This arrangement may lead to a further reduction of the susceptor material and may save costs.

[0031] The heat-spreading body may be attached to one side or both sides of the susceptor body. Such an arrangement may provides a simple manufacturing, and may provide a permanent contact between the susceptor body and the heat-spreading body with a maximum of heat transfer via heat conduction. The heat-spreading body may be adhered to one side or both sides of the susceptor body. Thus, a reliable fixture of the heat-spreading body to the susceptor body can be provided.

[0032] The heat-spreading body may be composed of two or more layers of heat conductive material. In such an arrangement, the susceptor body can be surrounded by two layers of heat conductive material. The two layers may be arranged on opposite sides of the susceptor body, so that the susceptor body is arranged between the two or more layers. This may improve the heat transfer of heat from the susceptor body to the heat-spreading body.

[0033] The susceptor body may be formed as a rod or a cylinder or a twisted wire extending along an axis. Hence, the susceptor body may form a stable backbone to support the heat-spreading body attached thereto.

[0034] The axis may be aligned with the longitudinal direction. The wing may extend in a radial direction with respect to said axis, wherein the radial direction may be aligned with the transversal direction.

[0035] The heat-spreading body may be extruded around the susceptor body. With this manufacturing step, complex cross-sections, like said wings of the heat-spreading body can be formed.

[0036] The susceptor body may comprise two end surfaces, particularly circular surfaces, and a shell surface arranged between these end surfaces, wherein the heat-spreading body may surround at least a part of or the entire shell surface. Such an arrangement may provide permanent contact between the susceptor body and the heat-spreading body with a maximum heat transfer via conduction.

[0037] The susceptor body and the heat-spreading body may be strip shaped flat bodies extending in two parallel planes, wherein the heat-spreading body may cover at least one of the two main surfaces of the susceptor body and may comprise two wings that laterally protrude beyond the covered main surface of the susceptor body on opposite sides. Such an arrangement may simplify the manufacturing of the arrangement while enabling a high heat transfer rate between the susceptor body and the heat-spreading body.

[0038] The susceptor body and the heat-spreading body may have the same length. Preferably this length is identical to the length of the aerosol-forming article. This may enable a possible bearing of the susceptor arrangement from the two end surfaces of the aerosol-forming article.

[0039] The heat-spreading body may partly or fully cover at least one of the two main surfaces of the susceptor body. Such an arrangement may provide permanent contact between the susceptor body and the heat-spreading body, entailing a maximum heat transfer via heat conduction.

[0040] The relation of a width of the susceptor body to the width of the heat-spreading body may be in a range between 0,4 and 0,75. Such an arrangement leads to reduction of the susceptor material and cost savings.

[0041] The (absolute) width of the susceptor body may be 2mm or more, but less than 4mm, preferably 3mm. With a common width of the aerosol-forming article of 5mm, a susceptor body of 2mm to 4mm in width would lead to a significant saving of susceptor material as compared to conventional solutions. The heat-spreading body may the same width as the aerosol-forming article (5mm). Hence, the heat-spreading body can be supported by the surfaces of the shell surface of the aerosol-forming article.

[0042] Parameters

[0043] Materials, thickness, width and configuration of the heat-spreading body may have an impact on aerosol performance, energy consumption, stick device compatibility, productivity, machinability and sustainability. Optimizing these parameters for the heat-spreading body is a trade-off between several and sometimes-contradictory demands. As an example, increasing the thickness of the heat-spreading body may support the thermal conductivity but on the other hand increase the weight and costs for manufacturing. Moreover, since the susceptor arrangement may form part of an aerosol-generating article and may be disposed together with the aerosolgenerating article after its consumption, materials, thickness and width may be designed not only with a view to maximize heating efficiency but also to minimizing the environmental impact during incineration or disposal. The thoughtful use of selected materials in aerosol-generating articles are also key to minimizing production costs. Using mono-materials and avoiding complex composites lowers raw material expenses and simplifies manufacturing. Reducing the amount of expensive materials - while maintaining functionality - further contributes to cost efficiency. A streamlined design that limits material usage enables economical large-scale production without compromising product performance.

[0044] Materials

[0045] The susceptor body may be partially or entirely made from a material selected from a group comprising: copper, a copper alloy, nickel, a nickel alloy, aluminum, an aluminum alloy.

[0046] The susceptor body may be partially or entirely made from steel, in particular AISI 430 steel.

[0047] The heat-spreading body may be partially or entirely made from a material selected from a group comprising: metal, carbon allotrope, preferably graphite or graphene, graphite sheet, preferably a pyrolytic graphite sheet or onyx. Onyx is a substrate composition comprising glycerin, graphite, fibers and ceramic, preferably 20% glycerin, 69% graphite, 7% fibers and 4% Ceramic Matrix Composite. Graphite may be most preferable in terms of thermal conductivity and also preferable in terms of electrical conductivity as well as sustainability. However, graphite may be more expensive than other materials. Metal and aluminum in particular may be most preferable in terms of electrical conductivity and also preferable in terms of thermal conductivity, but less preferable in terms of sustainability. Onyx may be preferable in terms of thermal conductivity, energy consumption, prices as well as sustainability, and may be less preferable in terms of electrical conductivity.

[0048] The heat-spreading body may be partially or entirely made from a material that 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 preferred greater than 1000 W / (m K). The material of the susceptor body may have a thermal conductivity different from, in particular less than, the material of the heat-spreading body, wherein the thermal conductivity of the material of the susceptor body may be above 25 W / (m K), in particular above 30 W / (m K), more particularly above 40 W / (m K). A relation between the thermal conductivity of the material of the heat-spreading body and the thermal conductivity of the material of the susceptor body may be in a range from 1.1 to 10 and / or may be greater than 1.5, preferably greater than 2, even more preferably greater than 2.5, in particular 3.

[0049] Fixation

[0050] The heat-spreading body may be fixed to the susceptor body. Such an arrangement may provide permanent contact between the susceptor body and the heat-spreading body, which may result in a high heat transfer rate by conduction.

[0051] The susceptor body may be press-fitted to the heat-spreading body, or vice-versa. The susceptor body may be connected to the heat-spreading body by press-fit or form fit, or vice- versa. The heat-spreading body may be adhered to the susceptor body by glue, preferably thermally conductive glue. Usable glues available commercially are for example the Durabond PC 8869 or Ipacoll LP 2741 PM produced by H.B. Fuller Adhesives. The heat-spreading body may be folded around the susceptor body. The heat-spreading body may be molded around the susceptor body, wherein the heat-spreading body may be extruded around the susceptor body. These fixation methods may provide customized and individual forming possibilities for the fixation of the susceptor to the heat-spreading body and vice-versa dependent on the susceptor arrangement.

[0052] Layers of susceptor body

[0053] The susceptor arrangement may comprise a separator body that is arranged between the susceptor body and the heat-spreading body. The separator body may provide several advantages compared to a direct contact of the susceptor body and the heat-spreading body.

[0054] The separator body may comprise at least one of: an electrical insulation layer configured to avoid a skin effect in the susceptor arrangement, an anti-diffusion layer configured to prevent diffusion of ions and / or build-up of electrical potential within the susceptor arrangement, a temperature marker layer with a specific Curie temperature configured to determine if the susceptor arrangement has reached a predetermined temperature and a protective layer configured to protect the susceptor arrangement from corrosion.

[0055] The separator body may be arranged on top of the temperature marker layer opposite to heat-spreading body. The heat-spreading body and the temperature marker layer may be coupled to each other. The protective layer may be coupled to the temperature marker layer opposite to the susceptor body.

[0056] Use

[0057] Another aspect disclosed herein relates to a susceptor arrangement according to any one of the preceding aspects for inductively heating an aerosol-forming substrate.

[0058] Heatable aerosol-generating article

[0059] Still another aspect disclosed herein relates to an inductively heatable aerosol-generating article, which may comprise an aerosol-forming substrate and at least one susceptor arrangement according to any one of the preceding aspects.

[0060] The aerosol-generating article may be a tobacco plug.

[0061] The tobacco plug may have a cylindrical shape. The tobacco plug may extend along a linear axis. The (longitudinal axis of the) susceptor body may be aligned with the linear axis of the tobacco plug.

[0062] 4. Terms and Definitions

[0063] As used herein, the term “aerosol-generating device” refers to a device that interacts with an aerosol-forming substrate of an aerosol-forming article to generate an aerosol. Preferably, the aerosol-generating device is a smoking device that interacts with an aerosol-forming substrate of an aerosol-forming article to generate an aerosol that is directly inhalable into a user’s lungs through the user's mouth. The aerosol-generating device may be a holder for a smoking article.

[0064] Preferably, the aerosol-forming article is a smoking article that generates an aerosol that is directly inhalable into a user’s lungs through the user's mouth. More preferably, the aerosolforming article is a smoking article that generates a nicotine-containing aerosol that is directly inhalable into a user’s lungs through the user's mouth.

[0065] As used herein, the term “aerosol-generating system” refers to a combination of an aerosolgenerating device and an aerosol-forming article, in which the aerosol-forming article and the aerosol-generating device cooperate to generate and deliver an aerosol to a user of the system.

[0066] As used herein, the term “aerosol-forming substrate” refers to a substrate consisting of or comprising an aerosol-forming material that is capable of releasing volatile compounds upon heating to generate an aerosol.

[0067] 5. List of non-limiting examples

[0068] The invention is defined in the claims. However, below there 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 another example, embodiment, or aspect described herein.

[0069] Example Ex1. A susceptor arrangement for inductively heating an aerosol-forming substrate, comprising an elongate susceptor body configured to generate heat by absorbing energy from a magnetic field; at least one thermally conductive heat-spreading body being made from a different material as compared to the susceptor body and configured to spread the heat generated by the susceptor body across the aerosol-forming substrate, wherein the heatspreading body extends along the elongate susceptor body and forms at least one wing that laterally protrudes beyond the susceptor body.

[0070] Example Ex1 .1 . A susceptor arrangement according to Example Ex1 , wherein the elongate susceptor body extends along a first direction.

[0071] Example Ex1.1.1. A susceptor arrangement according to Example Ex1.1 , wherein the first direction is the longitudinal direction.

[0072] Example Ex1.1.2. A susceptor arrangement according to Example Ex1.1 , wherein the susceptor body and / or heat-spreading body has its maximum extension (length) in the first direction.

[0073] Example Ex1.1.3. A susceptor arrangement according to Example Ex1.1 , wherein the susceptor body and the heat-spreading body have the same extension in the first direction.

[0074] Example Ex1.2. A susceptor arrangement according to Example Ex1 , wherein the wing protrudes beyond the susceptor body in a second direction, which is different from the first direction. Example Ex1.2.1. A susceptor arrangement according to Example Ex1.2, wherein the second direction is the transversal direction.

[0075] Example Ex1.2.2. A susceptor arrangement according to Example Ex1.2, wherein the second direction is orthogonal to the first direction.

[0076] Example Ex1.2.3. A susceptor arrangement according to Example Ex1.2, wherein the susceptor body and / or the heat-spreading body has its maximum width (not length) in the second direction.

[0077] Example Ex1.2.4. A susceptor arrangement according to Example Ex1.2, wherein the susceptor body and / or the heat-spreading body has a constant extension in the second direction over its entire extension in the first direction.

[0078] Example Ex1.2.5. A susceptor arrangement according to Example Ex1.2, wherein the heatspreading body has a greater extension than the susceptor body in the second direction.

[0079] Example Ex1.2.5.1. A susceptor arrangement according to Example Ex1.2.5, wherein the relation of an extension of the heat-spreading body to an extension of the susceptor body in the second direction is between 4 / 3 and 5 / 2.

[0080] Example Ex1.3. A susceptor arrangement according to Example Ex1 , wherein the wing extends in a plane.

[0081] Example Ex1.3.1. A susceptor arrangement according to Example Ex1 .3, wherein the plane is spanned by the first direction and the second direction.

[0082] Example Ex1.3.2. A susceptor arrangement according to Example Ex1.3, wherein the entire susceptor body extends in that plane or a parallel plane.

[0083] Example Ex1.3.3. A susceptor arrangement according to Example Ex1.3, wherein the entire heat-spreading body extends in that plane.

[0084] Example Ex1.4. A susceptor arrangement according to Example Ex1 , wherein the heatspreading body comprises two or more wings protruding beyond the susceptor body.

[0085] Example Ex1.4.1. A susceptor arrangement according to Example Ex1.4, wherein the wings extend in the same plane.

[0086] Example Ex1.4.2. A susceptor arrangement according to Example Ex1.4, wherein the wings are symmetrically arranged with respect to each other.

[0087] Example Ex1.4.3. A susceptor arrangement according to Example Ex1.4, wherein the wings protrude beyond different sides of the susceptor body.

[0088] Example Ex1.4.3.1. A susceptor arrangement according to Example Ex1.4.3, wherein the wings protrude beyond lateral sides of the susceptor body.

[0089] Example Ex1.4.3.2. A susceptor arrangement according to Example Ex1.4.3, wherein the wings protrude beyond opposite sides of the susceptor body. Example Ex1.5. A susceptor arrangement according to Example Ex1 , wherein the susceptor body has a self-supporting structure.

[0090] Example Ex1.6. A susceptor arrangement according to Example Ex1 , wherein the susceptor body forms a frame or skeleton.

[0091] Example Ex1.6.1. A susceptor arrangement according to Example Ex1.6, wherein the susceptor body comprises a backbone and limbs protruding from the backbone.

[0092] Example Ex1.6.1.1. A susceptor arrangement according to Example Ex1.6.1, wherein the wing extends between the limbs and preferably the backbone of the susceptor body.

[0093] Example Ex1.7. A susceptor arrangement according to Example Ex1, wherein a volume and / or a surface area of the susceptor body is less than that of the heat-spreading body.

[0094] Example Ex2. A susceptor arrangement according to any one of the preceding examples, wherein the heat-spreading body is or comprises at least one foil or strip.

[0095] Example Ex2.1. A susceptor arrangement according to Example Ex2, wherein the heat- spreading body is flexible.

[0096] Example Ex2.2. A susceptor arrangement according to Example Ex2, wherein the heat- spreading body extends in one plane.

[0097] Example Ex2.3. A susceptor arrangement according to Example Ex2, wherein the heat- spreading body has a polygonal outline.

[0098] Example Ex2.3.1. A susceptor arrangement according to Example Ex2.3, wherein the heatspreading body has a rectangular outline.

[0099] Example Ex2.3.1.1. A susceptor arrangement according to Example Ex2.3.1, wherein the longer side of the rectangle is aligned with the longitudinal direction.

[0100] Example Ex2.3.1.2. A susceptor arrangement according to Example Ex2.3.1, wherein the shorter side of the rectangle is aligned with the transversal direction.

[0101] Example Ex2.4. A susceptor arrangement according to Example Ex2, wherein the heatspreading body has a thickness of 2 to 180 pm, preferably 3 to 100 pm, more preferred 5 to 60 pm, in particular 12 to 20 pm, for example 3 to 30 pm or 30 pm to 60 pm.

[0102] Example Ex2.5. A susceptor arrangement according to Example Ex2, wherein the heatspreading body has a width of 1 to 7 mm, preferably 3 to 5 mm.

[0103] Example Ex2.6. A susceptor arrangement according to Example Ex2, wherein the heatspreading body has a thickness of 2 to 200 pm, preferably 3 to 100 pm, more preferred 5 to 100 pm, in particular 12 to 60 pm, for example 3 to 30 pm or 30 pm to 60 pm.

[0104] Example Ex3. A susceptor arrangement according to any one of the preceding examples, wherein the heat-spreading body partly or fully covers the susceptor body.

[0105] Example Ex3.1. A susceptor arrangement according to Example Ex3, wherein the susceptor body is partly or fully located inside the heat-spreading body. Example Ex3.2. A susceptor arrangement according to Example Ex3, wherein the susceptor body is partly or fully embedded within the heat-spreading body.

[0106] Example Ex3.3. A susceptor arrangement according to Example Ex3, wherein the susceptor body is partly or fully sandwiched between two layers of the heat-spreading body.

[0107] Example Ex3.4. A susceptor arrangement according to Example Ex3, wherein the heatspreading body is partly or fully folded around the susceptor body.

[0108] Example Ex3.5. A susceptor arrangement according to Example Ex3, wherein the heatspreading body is partly or fully wrapped around the susceptor body.

[0109] Example Ex4. A susceptor arrangement according to any one of the preceding examples, wherein the susceptor body is centrally arranged along a longitudinal direction of the susceptor arrangement.

[0110] Example Ex4.1 . A susceptor arrangement according to Example Ex4, wherein the susceptor body and the heat-spreading body are concentrically arranged with respect to the susceptor arrangement.

[0111] Example Ex4.2. A susceptor arrangement according to Example Ex4, wherein the heatspreading body is symmetrically arranged with respect to the susceptor body, or vice-versa.

[0112] Example Ex4a. A susceptor arrangement according to any one of the preceding examples, wherein the susceptor body and the heat-spreading body are provided laterally and / or londitudinally offset from one another.

[0113] Example Ex4a.1 A susceptor arrangement according to Example Ex4a, wherein the susceptor body and the heat-spreading body have the same width.

[0114] Example Ex4a.1.1 A susceptor arrangement according to Example Ex4a.1 , wherein the susceptor body and the heat-spreading body have the same thickness.

[0115] Example Ex4a.1.2 A susceptor arrangement according to Example Ex4a.1 , wherein the susceptor body and the heat-spreading body have a different thickness.

[0116] Example Ex4a.2 A susceptor arrangement according to Example Ex4a, wherein the susceptor body and the heat-spreading body have a different width.

[0117] Example Ex4a.2.1 A susceptor arrangement according to Example Ex4a.2, wherein the susceptor body and the heat-spreading body have the same thickness.

[0118] Example Ex4a.2.2 A susceptor arrangement according to Example Ex4a.2, wherein the susceptor body and the heat-spreading body have a different thickness.

[0119] Example Ex4a.2.3 A susceptor arrangement according to Example Ex4a.2.1 or Example Ex4a.2, wherein the susceptor body and the heat-spreading body are provided offset only on one side in a lateral and / or longitudinal direction and are flush on the other side. Example Ex4a.2.4 A susceptor arrangement according to Example Ex4a.2.1 or

[0120] Example Ex4a.2., wherein the susceptor body and the heat-spreading body are provided offset on each side in a lateral and / or longitudinal direction.

[0121] Example Ex5. A susceptor arrangement according to any one of the preceding examples, wherein the susceptor body has a flat or plane shape or has the shape of a layer or panel.

[0122] Example Ex5.1. A susceptor arrangement according to Example Ex5, wherein the susceptor body extends in one plane.

[0123] Example Ex5.2. A susceptor arrangement according to Example Ex5, wherein the susceptor body has a polygonal outline.

[0124] Example Ex5.2.1. A susceptor arrangement according to Example Ex5.2, wherein the susceptor body has a rectangular outline.

[0125] Example Ex5.2.1.1. A susceptor arrangement according to Example Ex5.2.1, wherein the longer side is aligned with the longitudinal or first direction.

[0126] Example Ex5.2.1.2. A susceptor arrangement according to Example Ex5.2.1, wherein the shorter side is aligned with the transversal or second direction.

[0127] Example Ex5.2.1.3. A susceptor arrangement according to Example Ex5.2.1, wherein the shorter side is shorter than the shorter side of the heat-spreading body.

[0128] Example Ex5.3. A susceptor arrangement according to Example Ex5, wherein the heatspreading body is attached to one side or both sides of the susceptor body.

[0129] Example Ex5.3.1. A susceptor arrangement according to Example Ex5.3, wherein the heatspreading body is adhered to one side or both sides of the susceptor body.

[0130] Example Ex6. A susceptor arrangement according to any one of the preceding examples, wherein the heat-spreading body is composed of two or more layers of heat conductive material.

[0131] Example Ex6.1. A susceptor arrangement according to Example Ex6, wherein the two layers are arranged on opposite sides of the susceptor body, so that the susceptor body is arranged between the two or more layers.

[0132] Example Ex7. A susceptor arrangement according to any one of the preceding examples, wherein the susceptor body is formed as a rod or a cylinder or a twisted wire extending along an axis.

[0133] Example Ex7.1. A susceptor arrangement according to Example Ex7, wherein the axis is aligned with the longitudinal direction.

[0134] Example Ex7.2. A susceptor arrangement according to Example Ex7, wherein the wing extends in a radial direction with respect to said axis.

[0135] Example Ex7.2.1. A susceptor arrangement according to Example Ex7.2, wherein the radial direction is aligned with the transversal direction. Example Ex7.3. A susceptor arrangement according to Example Ex7, wherein the heatspreading body is extruded around the susceptor body.

[0136] Example Ex7.4. A susceptor arrangement according to Example Ex7, wherein the susceptor body comprises two end surfaces, particularly circular surfaces, and a shell surface arranged between these end surfaces, wherein the heat-spreading body surrounds at least a part of or the entire shell surface.

[0137] Example Ex8. A susceptor arrangement according to any one of the preceding examples, wherein the susceptor body and the heat-spreading body are strip shaped flat bodies extending in two parallel planes, wherein the heat-spreading body covers at least one of the two main surfaces of the susceptor body and comprises two wings that laterally protrude beyond the covered main surface of the susceptor body on opposite sides.

[0138] Example Ex8.1 . A susceptor arrangement according to Example Ex8, wherein the susceptor body and the heat-spreading body have the same length.

[0139] Example Ex8.2. A susceptor arrangement according to Example Ex8, wherein the heatspreading body partly or fully covers at least one of the two main surfaces of the susceptor body.

[0140] Example Ex8.3. A susceptor arrangement according to Example Ex8, wherein the relation of the width of the susceptor body to the width of the heat-spreading body is between 0,4 and 0,75.

[0141] Example Ex8.4. A susceptor arrangement according to Example Ex8, wherein the width of the susceptor body is 2mm or more, but less than 4mm.

[0142] Example Ex8.4.1. A susceptor arrangement according to Example Ex8.4, wherein the width of the susceptor body is 3mm.

[0143] Example Ex8.4.2. A susceptor arrangement according to Example Ex8.4, wherein the heatspreading body has a maximum width of 5 mm.

[0144] Example Ex9. A susceptor arrangement according to any one of the preceding examples, wherein the susceptor body is partially or entirely made from a material selected from a group comprising: copper, a copper alloy, nickel, a nickel alloy, aluminum, an aluminum alloy.

[0145] Example Ex9.1 . A susceptor arrangement according to Example Ex9, wherein the susceptor body is partially or entirely made from steel, in particular AISI 430 steel.

[0146] Example Ex10. A susceptor arrangement according to any one of the preceding examples, wherein the heat-spreading body is partially or entirely made from a material selected from a group comprising: metal, carbon allotrope, preferably graphite or graphene, graphite sheet, preferably a pyrolytic graphite sheet or onyx.

[0147] Example Ex10.1. A susceptor arrangement according to Example Ex10, wherein the heatspreading body is partially or entirely made from a material that 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 preferred greater than 1000 W / (m K).

[0148] Example Ex11. A susceptor arrangement according to any one of the preceding examples, wherein the heat-spreading body is fixed to the susceptor body.

[0149] Example Ex11.1. A susceptor arrangement according to Example Ex11, wherein the susceptor body is press-fitted to the heat-spreading body, or vice-versa.

[0150] Example Ex11.2. A susceptor arrangement according to Example Ex11, wherein the susceptor body is connected to the heat-spreading body by form fit, or vice-versa.

[0151] Example Ex11.3. A susceptor arrangement according to Example Ex11 , wherein the heatspreading body is adhered to the susceptor body by glue.

[0152] Example Ex11.4. A susceptor arrangement according to Example Ex11 , wherein the heatspreading body is molded around the susceptor body.

[0153] Example Ex11.4.1. A susceptor arrangement according to Example Ex11.4, wherein heat-spreading body is extruded around the susceptor body.

[0154] Example Ex11.5. A susceptor arrangement according to Example Ex11 , wherein the heatspreading body is folded around the susceptor body.

[0155] Example Ex12. A susceptor arrangement according to any one of the preceding examples, wherein the susceptor arrangement comprises a separator body that is arranged between the susceptor body and the heat-spreading body.

[0156] Example Ex12.1. A susceptor arrangement according to Example Ex12, wherein the separator body comprises at least one of an electrical insulation layer configured to avoid a skin effect in the susceptor arrangement, an anti-diffusion layer configured to prevent diffusion of ions and / or build-up of electrical potential within the susceptor arrangement, a temperature marker layer with a specific Curie temperature configured to determine if the susceptor arrangement has reached a predetermined temperature, and / or a protective layer configured to protect the susceptor arrangement from corrosion.

[0157] Example Ex12.2. A susceptor arrangement according to Example Ex12, wherein the separator body comprises an electrical insulation layer configured to avoid a skin effect in the susceptor arrangement.

[0158] Example Ex12.3. A susceptor arrangement according to Example Ex12, wherein the separator body comprises an anti-diffusion layer configured to prevent diffusion of ions and / or build-up of electrical potential within the susceptor arrangement.

[0159] Example Ex12.4. A susceptor arrangement according to Example Ex12, wherein the separator body comprises a temperature marker layer with a specific Curie temperature configured to determine if the susceptor arrangement has reached a predetermined temperature. Example Ex12.5. A susceptor arrangement according to Example Ex12, wherein the separator body comprises a protective layer configured to protect the susceptor arrangement from corrosion.

[0160] Example Ex12.5.1. A susceptor arrangement according to Example Ex12.5, wherein the protective layer is arranged on top of the temperature marker layer opposite to the heatspreading body.

[0161] Example Ex12.5.2. A susceptor arrangement according to Example Ex12.5, wherein the heat-spreading body and the temperature marker layer are coupled to each other.

[0162] Example Ex12.5.3. A susceptor arrangement according to Example Ex12.5, wherein the protective layer is coupled to the temperature marker layer opposite to the susceptor body.

[0163] Example Ex13. Use of a susceptor arrangement according to any one of the preceding examples, for inductively heating an aerosol-forming substrate.

[0164] Example Ex14. An inductively heatable aerosol-generating article comprising an aerosolforming substrate and at least one susceptor arrangement according to any one of the preceding examples.

[0165] Example Ex15. An inductively heatable aerosol-generating article according to Example Ex14, wherein the aerosol-generating article is a tobacco plug.

[0166] Example Ex15.1. An inductively heatable aerosol-generating article according to Example

[0167] Ex15, wherein the tobacco plug has a cylindrical shape.

[0168] Example Ex15.2. An inductively heatable aerosol-generating article according to Example

[0169] Ex15, wherein the tobacco plug extends along a linear axis.

[0170] Example Ex15.3. An inductively heatable aerosol-generating article according to Example

[0171] Ex15, wherein the susceptor body is aligned with the linear axis of the tobacco plug.

[0172] 6. Brief Description of Drawings

[0173] The invention will be further described, by way of example only, with reference to the accompanying drawings in which:

[0174] Figure 1 is a schematic illustration of an aerosol-generating article comprising a susceptor arrangement according to a first embodiment.

[0175] Figure 2 is a schematic illustration of an aerosol-generating article comprising a susceptor arrangement according to a second embodiment.

[0176] Figure 3A shows a schematically possible configuration of a susceptor body having a flat rectangular shape;

[0177] Figure 3B shows an exploded view of a schematically possible configuration of susceptor arrangement comprising the susceptor body of Fig. 3A and one flat and rectangular heatspreading body arranged in parallel with the susceptor body, the heat-spreading body having a width greater than the width of the susceptor body; Figure 3C shows an exploded view of a schematically possible configuration of another susceptor arrangement comprising the susceptor body of Fig. 3A and flat and rectangular two heat-spreading bodies arranged in parallel with the susceptor body, the heat-spreading bodies having a width greater than the width of the susceptor body;

[0178] Figures 4A and 4B show in schematic sectional views further possible layer configurations of a susceptor arrangement;

[0179] Figure 5 shows schematically an inductively heatable aerosol-generating article comprising a susceptor arrangement according to the present invention;

[0180] Figure 6 shows schematically an aerosol-generating device comprising an aerosolgenerating article according to the present invention.

[0181] Figure 7 shows a sectional view of an aerosol-generating article comprising a susceptor arrangement according to a third embodiment.

[0182] Figure 8 shows a sectional view of multiple susceptor arrangements varying in thickness, width and structural configuration.

[0183] 7. Figure 9 shows a diagram of the glycerin and nicotine yield depending on the width / thickness relation and structural configuration of a graphite heat-spreading body. Detailed Description

[0184] The above and other features and advantages of example embodiments will become more apparent by describing in detail with reference to the attached drawings. However, specific structural and functional details disclosed herein are merely representative for purposes of describing the example embodiments. The example embodiments may, however, be embodied in many alternate forms and should not be construed as limited to only the embodiments set forth herein.

[0185] Accordingly, while the example embodiments are capable of various modifications and alternative forms, the embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that there is no intent to limit the example embodiments to the particular forms disclosed, but to the contrary, the example embodiments are to cover all modifications, equivalents, and alternatives falling within the scope of example embodiments. Like numbers refer to like elements throughout the description of the Figures.

[0186] Figure 1 is a schematic illustration of an aerosol-forming substrate 18 forming a cylindrical substrate element 12, such as a tobacco plug, for an aerosol-generating article. The substrate element 12 comprises a susceptor arrangement 1 according to a first embodiment that is concentrically arranged with the central axis of the cylindrical substrate element 12, representing a longitudinal or first direction. The susceptor arrangement 1 is configured and arranged to heat the aerosol forming substrate 18. For this reason, the susceptor arrangement 1 is fully embedded in the aerosol forming substrate 18 such as to be in direct thermal contact with the aerosol forming substrate 18. The aerosol-forming substrate 18 may have a length of 10 millimeters to 14 millimeters, for example, 12 millimeters.

[0187] The susceptor arrangement 1 comprises a susceptor body 2 with a susceptor body surface 3 and a heat-spreading body 4. The susceptor arrangement 1 has a rectangular flat shape extending from one end surface of the cylindrical substrate element 12 to the other. The heatspreading body 4 is a rectangular flat strip with a width W2 and is configured to spread the heat generated by the susceptor body 2 across the aerosol-forming substrate 18. The susceptor body 2 is a rectangular flat strip with a width W1 smaller than the width W2 of the heat-spreading body 4. The widths of the susceptor body surface 3 and the heat-spreading body 4 are measured in a second or transversal direction, orthogonal to the first direction. The heat-spreading body 4 and the susceptor body 2 are arranged in parallel. The relation of the width W2 of the heat-spreading body to the width W1 of the susceptor body 2 in the second direction is between 4 / 3 and 5 / 2.

[0188] The width W1 of the susceptor body 2 is 2mm or more, but less than 4mm, preferably 3mm. The heat-spreading body 4 has a maximum width W2 of 5 mm, which is limited by the diameter of the cylindrical substrate element 12.

[0189] With the susceptor body 2 having a smaller width W1 than the heat-spreading body 4, the heat-spreading body 4 extends along the susceptor body 2 and forms two wings 4a, 4b that laterally protrude beyond the susceptor body 2 in the second or transversal direction. In the longitudinal or first direction, the susceptor body 2 and the heat-spreading body 4 have the same length.

[0190] The susceptor body 2 is partially or entirely made from a material 6 selected from a group comprising: copper, a copper alloy, nickel, a nickel alloy, aluminum, an aluminum alloy. The heatspreading body 4 is partially or entirely made from a material selected from a group comprising: metal, carbon allotrope, preferably graphite or graphene, graphite sheet, preferably a pyrolytic graphite sheet. The susceptor body 2 can be a foil or strip, which can be flexible. The heatspreading body 4 may have a thickness in a range of 2 to 200 pm, preferably 3 to 180 pm, more preferred 5 to 100pm, in particular 12 to 60 pm, for example 3 to 30 pm or 30 pm to 60 pm. The thickness of the heat-spreading body 4 is preferably constant across its entire surface.

[0191] The heat-spreading body 4 is partially or entirely made from a material that 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 preferred greater than 1000 W / (m K).

[0192] The susceptor body 2 is fixed to the heat-spreading body 4 by press-fit or form fit or can be adhered to the heat-spreading body 4 by glue. In a possible variation of this embodiment, the heat-spreading body 4 is partially or entirely made from a material selected from a group comprising: metal, carbon allotrope, preferably graphite or graphene, graphite sheet, preferably a pyrolytic graphite sheet or onyx. Onyx and graphite are favorable materials in terms of performance and productivity. The susceptor body 2 can be a foil or strip, which can be flexible. The heat-spreading body 4 may have a thickness in a range of 2 to 200 pm, preferably 3 to 100 pm, more preferred 5 to 100 pm, in particular 12 to 60 pm, for example 3 to 30 pm or 30 pm to 60 pm.

[0193] Figure 2 is a schematic illustration of an aerosol-forming substrate 18 forming a cylindrical substrate element 12 comprising a susceptor arrangement 1 according to a second embodiment. The basic structure of the cylindrical substrate element 12 and the susceptor arrangement 1 corresponds to that of the first embodiment, which is why the same parts are not described.

[0194] In the second embodiment, the susceptor body 2 is a twisted rod shaped wire extending along the longitudinal direction. The susceptor body 2 is embedded between two layers of the heat-spreading body 4, such that the susceptor body 2 is fully located inside the heat-spreading body 4. The two layers of the heat-spreading body 4 form two wings 4a, 4b which laterally / radially protrude from the susceptor body 2.

[0195] Each of the two layers of the heat-spreading body 4 may be a rectangular flat strip, wherein the two layers have the same size and are adhered to each other to enclose the susceptor body 2.

[0196] Figure 3A shows a schematically possible configuration of a susceptor body 2 forming a rectangular flat strip or sheet. The susceptor body 2 has a first susceptor body surface 3’ and a second susceptor body surface 3”. The susceptor body 2 has a width W1 in a transversal direction. Figure 3B shows an exploded view of a schematically possible configuration of a susceptor arrangement 1 with the susceptor body 2 of Fig. 3A and one heat-spreading body 4 that also forms a rectangular flat strip or sheet. The heat-spreading body 4 has a width W2 in a transversal direction. The width W2 of the heat-spreading body 4 is bigger than the width W1 of the susceptor body 2. The relation of the width W1 of the susceptor body 2 to the width W2 of the heat-spreading body 4 is between 0,4 and 0,75. Figure 3C shows an exploded view of a schematically possible configuration of another susceptor arrangement 1 with the susceptor body 2 of Fig. 3A and two heat-spreading bodies 4, 5 that also form rectangular flat strips or sheets. The first (top) susceptor body surface 3’ of the susceptor body 2 is covered with a first heatspreading body 4 and the second (bottom) susceptor body surface 3” is additionally covered with a second heat-spreading body 5. A width W2 of the second heat-spreading body 5 is the same as the width W2 of the first heat-spreading body W1 . The first and second heat-spreading bodies 4, 5 may be formed from the same material, but may also be of a different material. If fixed to each other, the first and second heat-spreading bodies 4, 5 may be regarded as layers, which together form one heat-spreading body 4, 5.

[0197] Another possible configuration of a susceptor arrangement 1 is shown in Figure 4A. The susceptor arrangement 1 comprises a susceptor body 2, which comprises a first susceptor material 6 with a first susceptor body surface 3’ and a second susceptor body main surface 3”. The first susceptor material 6 is steel, in particular AISI 430 steel. The susceptor body 2 may have a thickness of up to 60 micrometers. A heat-spreading body 4 is in thermal contact with the first susceptor body surface 3’ and has a thickness between 12 micrometers and 16 micrometers. The heat-spreading body 4 is intimately coupled to the susceptor body 2 and comprises at least a heat-spreading material, preferably a carbon allotrope or a metal, as described above. A temperature marker layer 7 is intimately coupled to the heat-spreading body 4 opposite to the susceptor body 2. The temperature marker layer 7 is made of FeNi80Mo alloy, and has a thickness between 6 micrometers and 8 micrometers. A protective layer 8 is intimately coupled to the temperature marker layer 7. The protective layer 8 is made of steel, in particular AISI 430 steel, and has a thickness of 3.5 micrometers.

[0198] Alternatively, as shown in Figure 4B, a separation body 9 is arranged between the susceptor body 2 and the heat-spreading body 4. The separation layer 9 is made of an antidiffusion material and has a thickness of 6 micrometers. The separator body 9 may be arranged between the susceptor body 2 and the heat-spreading body 4. The separator body 9 may preferably comprise at least one of an electrical insulation layer, an anti-diffusion layer, a temperature marker layer 7 with a specific Curie temperature, and a protective layer 8.

[0199] The temperature marker layer 7 is intimately coupled to the heat-spreading body 4 opposite to the susceptor body 2. The temperature marker layer 7 is made of FeNi80Mo alloy, and has a thickness between 6 micrometers and 8 micrometers. The protective layer 8 is intimately coupled to the temperature marker layer 7. The protective layer 8 is made of steel, in particular AISI 430 steel, and has a thickness of 3.5 micrometers.

[0200] The separation layer may be advantageous for providing additional functions to the susceptor arrangement 1. The electrical insulation layer may be advantageous for avoiding a “skin effect” in the susceptor arrangement 1 , where induced eddy currents at high frequencies tend to flow mainly at the outer surface of the susceptor. In particular, the induced eddy currents tend to flow between the outer surface and a level called the skin depth. By providing the electrical insulation layer between the susceptor body 2 and the heat spreading body 4, the induced eddy currents may be limited to the susceptor body 2, where they can provide more energy losses and hence more heat.

[0201] Fig. 5 shows schematically an inductively heatable aerosol-generating article 10 comprising a susceptor arrangement 1 according to the present invention (not to scale). The aerosol- generating article 10 is a substantially rod-shaped consumable comprising five elements sequentially arranged in coaxial alignment: a distal front plug element 11 , a substrate element 12, a first tube element 13, a second tube element 14, and a filter element 15. The distal front plug element 11 is arranged at a distal end 16 of the aerosol-generating article 10 to cover and protect the distal front end of the substrate element 12, whereas the filter element 15 is arranged at a proximal end 17 of the aerosol-generating article 10. Both the distal front plug element 11 and the filter element 15 may be made of the same filter material. The filter element 15 preferably serves as a mouthpiece, preferably as part of a mouthpiece together with the second tube element 14.

[0202] The filter element 15 may have a length of 10 millimeters to 14 millimeters, for example, 12 millimeters, whereas the distal front plug element 11 may have a length of 3 millimeters to 6 millimeters, for example, 5 millimeters. The substrate element 12 comprises an aerosol-forming substrate 18 to be heated as well as a susceptor arrangement 1 according to the present invention, for example as shown in Figs. 1 to 4, that is configured and arranged to heat the aerosol forming substrate 18. For this, the susceptor arrangement 1 is fully embedded in the aerosol forming substrate 18 such as to be in direct thermal contact with the aerosol forming substrate 18. The substrate element 12 may have a length of 10 millimeters to 14 millimeters, for example, 12 millimeters. Each one of the first and the second tube element 13, 14 is a hollow cellulose acetate tube having a central air passage 19, 20, wherein a cross-section of the central air passage 20 of the second tube element 14 is larger than a cross-section of the central air passage 19 of the first tube element 13. The first and second tube elements 13, 14 may have a length of 6 millimeters to 10 millimeters, for example, 8 millimeters.

[0203] In use, an aerosol formed by volatile compounds released from the substrate element 12 upon heating is drawn through the first and second tube elements 13, 14 and the filter element 15 towards the proximal end 17 of the aerosol-generating article 10. Each of the aforementioned elements 11 , 12 ,13, 14, 15 may be substantially cylindrical. In particular, all elements 11 , 12 ,13, 14, 15 may have the same outer cross-sectional shape and dimensions.

[0204] In addition, the elements may be surrounded and held together by one or more outer wrappers to form a rod-shaped article with a desired cross-sectional shape. The distal front plug element 11 , the substrate element 12 and the first tube element 13 are surrounded by a wrapper 21. Preferably, the wrapper 21 is made of paper.

[0205] As shown in Fig. 6, the aerosol-generating article 10 according to Fig. 5 is configured for use in combination with an inductively heating aerosol-generating device 23. Together, the aerosol-generating device 23 and the aerosol-generating article 10 form an aerosol-generating system 24. The aerosol-generating device 23 comprises a cylindrical receiving cavity 25 defined within a proximal portion 26 of the aerosol-generating device 23 for receiving a least a distal portion of the aerosol-generating article 10 therein. The aerosol-generating device 23 further comprises an inductive heating arrangement including an induction coil 27 for generating an alternating, in particular high-frequency magnetic field within the cylindrical receiving cavity 25. The induction coil 27 is a helical coil circumferentially surrounding the cylindrical receiving cavity 25. The induction coil 27 is arranged such that the susceptor arrangement 1 of the aerosolgenerating article 10 is exposed to a magnetic field upon inserting the aerosol-generating article 10 into the cylindrical receiving cavity 25 of the aerosol-generating device 23. Thus, when activating the inductive heating arrangement, the susceptor arrangement 1 heats up due to eddy currents and / or hysteresis losses that are induced by the alternating magnetic field, depending on the magnetic and electric properties of the susceptor materials of the susceptor arrangement 1 . The susceptor arrangement 1 is heated until reaching an operating temperature sufficient to vaporize the aerosol-forming substrate 18 surrounding the susceptor arrangement 1 within the aerosol generating article 10. Within a distal portion 28, the aerosol-generating device 23 further comprises a DC power supply 29 and a controller 30 (only schematically illustrated in Figure 6) for powering and controlling the heating process. Apart from the induction coil 27, the inductive heating arrangement preferably is at least partially an integral part of the controller 30.

[0206] Figure 7 shows a sectional view of an aerosol-generating article 12 comprising a susceptor arrangement 1 according to a third embodiment. The susceptor arrangement 1 is embedded in the aerosol-forming substrate 18, depicted as a circle in the sectional view. The susceptor body 2 and the heat-spreading body 4 have the same width and thickness, preferable 3 mm and 100 pm. The heat-spreading body 4 is arranged offset to the susceptor body 2. In other words, an end section 4a or wing of the heat-spreading body 4 laterally protrudes beyond the susceptor body 2. On the other end, an end section 2a of the susceptor body 2 protrudes from the heat-spreading body 4. With this arrangement, a higher overall surface of the susceptor body 2 facing the aerosolforming substrate 18 can be provided, while also the surface of the heat-spreading body 4 facing the aerosol-forming substrate 18 can be enhanced. This arrangement is preferred when a smaller contact area between the susceptor body 2 and the heat-spreading body 4 is sufficient to transfer the heat from the susceptor body 2 to the heat-spreading body 4. This might optimize the transmission of the heat from the susceptor arrangement 1 to the aerosol-forming substrate 18. In the above-described third embodiment, the susceptor arrangement 1 is positioned in the aerosol-forming substrate 18, such that only the susceptor body 2 is centrally arranged in the aerosol-generating article 12. However, the susceptor body 2 can also be arranged in the aerosolforming substrate 18, such that the entire susceptor arrangement 1 is centrally arranged in the aerosol-generating article 12.

[0207] Figure 8 shows eight Examples A to H of susceptor arrangements 1 of different structural configurations with heat-spreading bodies 4 of different thicknesses and widths. In all Examples, the susceptor body 2 is identical and has the same width of preferably 3 mm and the same thickness of preferably 100 pm. Example A shows a susceptor arrangement 1 , wherein the susceptor body 2 and the heat-spreading body 4 have the same width and the same thickness and are congruent. Example B shows a susceptor arrangement 1 according to Fig. 7, wherein the susceptor body 2 and the heat-spreading body 4 have the same width and the same thickness but are offset. Example C shows a susceptor arrangement 1 , wherein the heat-spreading body 4 is wider than the susceptor body 2, preferably 5 mm, and wherein the heat-spreading body 4 and the susceptor body 2 have the same thickness. The heat-spreading body 4 and the susceptor body 2 of Example C are offset from each other, such that both end sections of the heat-spreading body 4 laterally protrude beyond the susceptor body 2. Example D shows a susceptor arrangement 1 , wherein the heat-spreading body 4 is wider than the susceptor body 2, preferably having a width of 5 mm, and wherein the heat-spreading body 4 and the susceptor body 2 have the same thickness. The heat-spreading body 4 and the susceptor body 2 of Example D are laterally offset, such that one end section or wing of the heat-spreading body 4 laterally protrudes beyond the susceptor body 2 while the other end section of the heat-spreading body 4 is flush with the susceptor body 2, but wherein the end sections of the susceptor body 2 and the heatspreading body 4 on the opposite side of the susceptor arrangement 1 are aligned in the same plane without any offset. Examples E to H are almost identical to the Examples A to D, with the only difference that the thickness of the heat-spreading body 4 is 180 pm instead of 100 pm.

[0208] Glycerin and nicotine are both key components of the aerosol that is generated from an aerosol-generating article to be inhaled by a user. An analysis was performed with heat-spreading bodies 4 made from graphite and configurations according to the Examples A to H in order to investigate their impact of the on the content of glycerin and nicotine in the aerosol. As the susceptor body 2 is identical in all Examples A to H, the impact of the susceptor body 2 on this analysis is eliminated / negligible. Figure 9 shows a diagram with boxplots of the glycerin and nicotine yields depending on the width / thickness relation and the structural configuration of the heat-spreading body 4. The yields are presented in the unit pg per stick, i.e. per heatable aerosolgenerating article 10. As mentioned above, each of the Examples A to H comprises a susceptor body 2 with a width of 3 mm and a heat-spreading body 4 made from graphite.

[0209] In Fig. 9, the Y-Axis of the glycerin (top) and nicotine yields (bottom) and given in the unit pg / stick are depicted over the X-Axis listing the multiple Examples A to H. The Examples A, C, E, G having a centered configuration are depicted with a bar having horizontal strips, while the Examples B, D, F, H having a laterally offset configuration are depicted with a bar having vertical stripes. The results are shown as boxplots. Therein, the median is shown by a thick line and the dispersion is shown using boxes. This means that the skewness and possible outliers of data can be shown at a glance in addition to the position and dispersion. Additionally, a yield value for a 4 mm susceptor is provided as a reference value. Figure 9 shows that all Examples A to H provide a superior deliverance of glycerin and nicotine yield as compared to the reference line, relating to the susceptor with 4mm width (but without a heat spreading body 4). Examples B and D having a heat spreading body 4 with a smaller thickness of 100 pm and an offset configuration with respect to the susceptor body 2 show the best values regarding the glycerin yield. For the Examples E to H having a heat spreading body 4 of a greater thickness of 200 pm, the centered configuration according to the Examples E and G revealed a higher glycerin yield than the offset configuration according the Examples F and H. One may conclude from this analysis that the width of the heat-spreading layer 4 has high impact for glycerin and nicotine deliveries, whereas the thickness of the heat-spreading layer 4 has only little impact for glycerin and nicotine deliveries.

[0210] Further analyses were conducted employing heat-spreading bodies 4 composed of Aluminum and Onyx, and configured in accordance with the Examples A, C, E, G, in order to assess the impact of materials on glycerin and nicotine yields. The heat-spreading bodies 4 were provided with widths of 3 mm or 5 mm, and thicknesses of 100 pm or 200 pm, respectively. It was observed that, for a width of 5 mm, both Aluminum and Onyx resulted in superior delivery rates of glycerin and nicotine in the aerosol. Variations in the thickness of the heat-spreading body 4, within the tested range, exhibited only a minor effect on the yield of glycerin and nicotine.

[0211] In summary, it has been found that an increased width ratio, specifically a width of 5 mm compared to 3 mm, between the heat-spreading layer 4 and the susceptor body 2 is generally advantageous for achieving improved glycerin and nicotine yields in the aerosol. When the heatspreading layer 4 and the susceptor body 2 are arranged in an offset configuration, a reduction in the thickness of the heat-spreading layer 4 can lead to an enhancement in the delivery of aerosol constituents, such as glycerin and nicotine. Conversely, when the heat-spreading layer 4 and the susceptor body 2 are arranged in a congruent or centered manner, an increased thickness of the heat-spreading layer 4 may contribute positively to the aerosol yield. Among the materials tested, Graphite, Aluminum, and Onyx have demonstrated superior performance as heat-spreading materials, particularly when employed with a layer width of 5 mm, indicating their suitability for use in aerosol generating systems.

[0212] For the purpose of the present description and of the appended claims, except where otherwise indicated, all numbers expressing amounts, quantities, percentages, and so forth, are to be understood as being modified in all instances by the term "about". Also, all ranges include the maximum and minimum points disclosed and include any intermediate ranges therein, which may or may not be specifically enumerated herein. In this context, therefore, a number A is understood as A ± 5% of A. Within this context, a number A may be considered to include numerical values that are within general standard error for the measurement of the property that the number A modifies. The number A, in some instances as used in the appended claims, may deviate by the percentages enumerated above provided that the amount by which A deviates does not materially affect the basic and novel characteristic(s) of the claimed invention. Also, all ranges include the maximum and minimum points disclosed and include any intermediate ranges therein, which may or may not be specifically enumerated herein.

Claims

CLAIMS1. A susceptor arrangement (1) for inductively heating an aerosol-forming substrate (18), comprising: an elongate susceptor body (2) configured to generate heat by absorbing energy from a magnetic field; at least one thermally conductive heat-spreading body (4) being made from a different material as compared to the susceptor body (2) and configured to spread the heat generated by the susceptor body (2) across the aerosol-forming substrate (18), wherein the heat-spreading body (4) extends along the elongate susceptor body (2) and forms at least one wing that laterally protrudes beyond the susceptor body (2).

2. The susceptor arrangement according to the preceding claim, wherein the heat-spreading body (4) is or comprises at least one foil or strip.

3. The susceptor arrangement according to one of the preceding claims, wherein heatspreading body (4) partly or fully covers the susceptor body (2).

4. The susceptor arrangement according to one of the preceding claims, wherein the susceptor body (2) is centrally arranged along a longitudinal direction of the susceptor arrangement (1).

5. The susceptor arrangement according to one of the preceding claims, wherein the susceptor body (2) and the heat-spreading body (4) are provided laterally and / or longitudinally offset from one another.

6. The susceptor arrangement according to one of the preceding claims, wherein the susceptor body (2) has a flat or plane shape or has the shape of a layer or panel.

7. The susceptor arrangement according to one of the preceding claims, wherein the heatspreading body (4) is composed of two or more layers of heat conductive material.

8. The susceptor arrangement according to one of the preceding claims, wherein the susceptor body (2) is formed as a rod or a cylinder or a twisted wire extending along an axis.

9. The susceptor arrangement according to one of the preceding claims, wherein the susceptor body (2) and the heat-spreading body (4) are strip shaped flat bodies extending in twoparallel planes, wherein the heat-spreading body (4) covers at least one of the two main surfaces of the susceptor body (2) and comprises two wings that laterally protrude beyond the covered main surface of the susceptor body (2) on opposite sides.

10. The susceptor arrangement according to one of the preceding claims, wherein the susceptor body (2) is partially or entirely made from a material (6) selected from a group comprising: copper, a copper alloy, nickel, a nickel alloy, aluminum, an aluminum alloy.11 . The susceptor arrangement according to one of the preceding claims, wherein the heatspreading body (4) is partially or entirely made from a material selected from a group comprising: metal, carbon allotrope, preferably graphite or graphene, graphite sheet, preferably a pyrolytic graphite sheet or onyx.

12. The susceptor arrangement according to one of the preceding claims, wherein the heatspreading body (4) is fixed to the susceptor body (2).

13. The susceptor arrangement according to one of the preceding claims, wherein the susceptor arrangement (1) comprises a separator body (9) that is arranged between the susceptor body (2) and the heat-spreading body (4).

14. Use of a susceptor arrangement (1) according to any one of the preceding claims for inductively heating an aerosol-forming substrate (18).

15. An inductively heatable aerosol-generating article comprising an aerosol-forming substrate and at least one susceptor arrangement (1) according to any one of the preceding claims.

16. The inductively heatable aerosol-generating article according to the preceding claim, wherein the aerosol-generating article is a tobacco plug.

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