Aerosol-generating article for use with induction-heated aerosol-generating device

Abstract

The present disclosure relates to an aerosol-generating article (100) for use with an induction-heated aerosol-generating device (10). An article comprises an aerosol-forming substrate (130) and a susceptor device (120) for heating the aerosol-forming substrate by interaction of the susceptor device with an alternating magnetic field provided by an aerosol-generating device wherein the aerosol-forming substrate comprises at least one aerosol-forming agent and at least one sensory material, the at least one aerosol former and the at least one sensory material are volatilizable when heated. The susceptor device comprises a plurality of elongate susceptor elements (121) comprising a susceptor material dispersed throughout the aerosol-forming substrate wherein the ratio of a maximum length dimension of the elongate susceptor elements to a maximum lateral dimension of the elongate susceptor elements perpendicular to the length dimension is greater than 4. The present disclosure also relates to an aerosol-generating system comprising such an article and an induction heated aerosol-generating device for use with an article.

Description

[0001] The present disclosure relates to an aerosol-generating article for use with an induction-heated aerosol-generating device. The present disclosure also relates to an aerosol-generating system comprising such an article and an induction-heated aerosol-generating device for use with the article.

[0002] Aerosol generating systems that use induction heating to generate inhalable aerosols are well known from the prior art. Such systems may include an induction-heated aerosol generating device and a separate aerosol-generating article for use with the device. Together with other components, the article may include an aerosol-forming substrate capable of forming an inhalable aerosol when heated, and an inductively heatable susceptor device that is in thermal proximity to or in direct physical contact with the substrate for heating the substrate. The inductive heating of the susceptor device is achieved by the interaction of the susceptor device with an alternating magnetic field provided by the aerosol generating device. In operation, the alternating magnetic field induces at least one of heat-generating eddy currents or hysteresis losses in the susceptor device, thereby heating the susceptor device to a temperature sufficient to release volatile compounds from the heated substrate, which volatile compounds can then cool to form an aerosol.

[0003] Different configurations of susceptor element / susceptor arrangements are known, depending on the type of substrate and the shape of the article. For example, an article may include a single solid susceptor element, such as a susceptor strip, embedded in a solid or gel-like aerosol-forming substrate within the substrate portion of the article. Although solid susceptor elements are readily available at low cost, they form a single central heat source, which can lead to a non-uniform temperature distribution across the substrate portion. This is because direct heating of the substrate occurs only in the immediate vicinity of the susceptor element, while the peripheral regions of the substrate portion are heated only indirectly via heat conduction across adjacent substrate layers. In particular, high temperature gradients can cause the interior regions of the substrate portion near the susceptor element to overheat, while temperatures in the peripheral regions of the substrate portion may be too low to volatilize the substrate. Furthermore, the heating efficiency of this configuration is quite sensitive to the proper positioning of the susceptor element within the substrate. All of this can lead to suboptimal utilization of the aerosol-forming substrate. Alternatively, articles have been proposed that include spherical or quasi-spherical susceptor particles uniformly dispersed throughout the aerosol-forming substrate. While resulting in more uniform heating of the substrate, this susceptor configuration has limited heating efficiency, which can also affect extraction efficiency.

[0004] It would therefore be desirable to have an inductively heatable aerosol-generating article and an aerosol-generating system including such an article that have the advantages of prior art solutions while alleviating the limitations of such solutions. In particular, it would be desirable to have an inductively heatable aerosol-generating article and an aerosol-generating system including such an article that provide for more efficient heating and utilization of an aerosol-forming substrate.

[0005] According to one aspect of the present invention, an aerosol-generating article for use with an induction-heated aerosol-generating device is provided. The article comprises an aerosol-forming substrate and a susceptor device for heating the aerosol-forming substrate through interaction between the susceptor device and an alternating magnetic field provided by the aerosol-generating device, wherein the aerosol-forming substrate comprises at least one aerosol-forming agent and at least one sensory material, the at least one aerosol-forming agent and the at least one sensory material being volatile upon heating. In particular, the aerosol-forming substrate is a solid aerosol-forming substrate. The susceptor device comprises a plurality of elongated susceptor elements comprising or consisting of the susceptor material, the plurality of elongated susceptor elements being dispersed throughout the aerosol-forming substrate. In particular, the elongated susceptor elements are one of fiber elements, filament elements, thread elements, granular elements, or strip elements. The fiber elements may be chopped fiber elements or milled fiber elements. The ratio of the maximum length dimension of the elongated susceptor elements to the maximum transverse dimension of the elongated susceptor elements perpendicular to the (maximum) length dimension is greater than 4.

[0006] As used herein, the term "elongated susceptor element" refers to a susceptor element having a greater extent in one primary dimension than in the two remaining dimensions perpendicular to the primary dimension. Thus, an elongated susceptor element may also be denoted as a 1D elongated susceptor element (a synonym for a one-dimensional elongated susceptor element) or a quasi-1D susceptor element (a synonym for a quasi-1D susceptor element). In particular, the term "elongated susceptor element" may refer to a susceptor element having a length dimension that is greater than any transverse dimension perpendicular to the length dimension. More particularly, a 1D elongated susceptor element may be an elongated or prolate susceptor element.

[0007] Compared to a single solid susceptor element, the use of multiple elongated susceptor elements dispersed throughout the aerosol-forming substrate advantageously produces a more uniform heat distribution across the substrate, without any significant temperature gradients across different substrate regions. Furthermore, in cases where the susceptor material of the susceptor elements has a high thermal conductivity, the uniformity of the heat distribution is further enhanced by the fact that a substrate including multiple susceptor elements dispersed therein exhibits an increased equivalent thermal conductivity compared to a substrate without susceptor elements or a substrate having only a single solid susceptor element. Furthermore, compared to a single solid susceptor element, the proposed susceptor device is less sensitive to the positioning of the susceptor elements in achieving a uniform heat distribution.

[0008] Most importantly, it was found that the geometry of the susceptor element, and in particular its relative size, has a significant impact on the heating efficiency and, therefore, the extraction efficiency of the matrix. In this regard, susceptor elements with an elongated shape were found to be less susceptible to demagnetization effects than comparable equidimensional susceptor elements, such as spherical or quasi-spherical susceptor particles. This can be explained as follows: When a susceptor element is placed in an external magnetic field, it gradually becomes magnetized. As the external field increases, so does the internal magnetization. This process continues until the magnetization reaches the material's magnetic saturation point, beyond which no further magnetization occurs. Consequently, the magnetization of the susceptor element causes a buildup of magnetic charge density at opposite ends of the susceptor element, as seen in the direction of the external magnetic field. Consequently, the susceptor element generates a magnetic field that induces a self-interaction with its material. This field lies in the same direction as the external magnetic field, but points in the opposite direction, and is therefore referred to as the demagnetization field. The demagnetization field depends on the susceptor element's geometry, but not its absolute size. Assuming that a susceptor element changes in response to an external magnetic field, it is generally assumed that the demagnetization field is proportional to the magnetization in each direction, related by a geometrically related proportionality constant known as the demagnetization factor. The demagnetization factor depends on the shape of the susceptor element and its relative orientation with respect to the external magnetic field. In this regard, it has been found that an external magnetic field extending through an elongated susceptor element (such as a susceptor element having a fiber or thin strip shape) with a length dimension significantly greater than any transverse dimension perpendicular to the length dimension produces a weaker or even negligible demagnetization field compared to a non-elongated (equidimensional) susceptor element, such as a spherical or quasi-spherical susceptor element. This is intuitively understandable because, in a properly aligned elongated susceptor element, the cumulative magnetic charge densities at the opposing ends of the susceptor element are spatially farther apart. This significantly reduces the demagnetization field's strength, and thus has less impact on the magnetization field, which contributes to power loss. Consequently, power loss, and therefore heating efficiency, is greater for elongated susceptor elements than for non-elongated (equidimensional) susceptor elements, such as spherical or quasi-spherical susceptor elements. This is particularly true when the magnetic field is substantially parallel to the length dimension of the elongated susceptor element. However, when considering a collection of susceptor elements, even if the elongated susceptor elements are not all aligned parallel to the alternating magnetic field, but are randomly oriented, the overall heating performance of the collection of elongated susceptor elements is still higher on a statistical average than the overall heating performance of the collection of non-elongated (equidimensional) susceptor elements. Thus, in any case, the overall heating performance of the proposed susceptor device of a plurality of elongated susceptor elements is higher than that of a similar configuration of non-elongated (equidimensional) susceptor elements, regardless of whether the elongated susceptor elements are dispersed throughout the substrate in a random orientation or in an orientation parallel to the alternating magnetic field used for induction heating.

[0009] In summary, the high power available, the increased thermal conductivity of the substrate, and the uniform heat distribution into the substrate allow for rapid heating of the aerosol-forming substrate. Advantageously, the heat-up time can be less than 0.5 milliseconds. The reduced heat-up time and the low thermal gradient across the substrate even allow for a puff-on-demand strategy based on delivering instantaneous or quasi-instantaneous power only when the user needs an aerosol in order to heat the substrate and generate an aerosol, while during the waiting dwell time, the power supplied to the substrate is low or zero.

[0010] According to the present invention, it has been found that the heating efficiency and, therefore, the extraction efficiency of the matrix is ​​particularly enhanced if the ratio of the maximum length dimension of the elongated susceptor element to the maximum transverse dimension of the elongated susceptor element perpendicular to the (maximum) length dimension is greater than 4, in particular greater than 10, preferably greater than 20, more preferably greater than 25, even more preferably greater than 30, and most preferably greater than 35. As used herein, the ratio of the maximum length dimension of the elongated susceptor element to the maximum transverse dimension of the elongated susceptor element perpendicular to the length dimension is also denoted as the shape factor or aspect ratio. Thus, the shape factor of the elongated susceptor element is greater than 4, in particular greater than 10, preferably greater than 20, more preferably greater than 25, even more preferably greater than 30, and most preferably greater than 35.

[0011] Whenever a number or range is given in the present disclosure for a plurality of objects (such as for a plurality of susceptor elements), this means that the number or range applies to at least 60%, particularly at least 70%, more particularly at least 80%, and especially at least 90%, of all objects in the plurality of objects, preferably to all objects in the plurality of objects. For example, when the present disclosure states that the shape factor of an elongated susceptor element is greater than A, this means that at least 60%, particularly at least 70%, more particularly at least 80%, and especially at least 90% of all elongated susceptor elements of the susceptor device have a shape factor greater than A.

[0012] Preferably, the ratio of the maximum length dimension to the maximum transverse dimension (shape factor) has not only a lower limit but also an upper limit. Thus, the ratio of the maximum length dimension of the elongated susceptor element to the maximum transverse dimension perpendicular to the (maximum) length dimension (i.e., the shape factor of the elongated susceptor element) may be in the range of 4 to 500, in particular 10 to 300, preferably 20 to 200, more preferably 30 to 100.

[0013] In absolute numbers, the maximum length dimension of the elongated susceptor elements may be in the range of between 0.02 μm and 50 mm, in particular between 1 μm and 16 mm, preferably between 0.1 mm and 5 mm. Such maximum length dimensions may prove advantageous in dispersing the susceptor elements throughout the aerosol-forming substrate.

[0014] Depending on the respective absolute values ​​of the maximum length dimension, the respective absolute values ​​of the maximum transverse dimension of the elongated susceptor element are preferably selected such that the shape factor is above the lower limit defined above, and advantageously also within the preferred range defined above. Thus, the maximum transverse dimension of the elongated susceptor element may be equal to or less than 500 micrometers, in particular equal to or less than 100 micrometers, preferably equal to or less than 10 micrometers, and more preferably equal to or less than 1 micrometer. Similarly, the maximum transverse dimension of the elongated susceptor element may be in the range between 0.005 micrometers and 500 micrometers, in particular between 0.1 micrometers and 150 micrometers, and preferably between 20 micrometers and 100 micrometers. As an example, the elongated susceptor element may have a length dimension of approximately 2 millimeters and a transverse dimension of approximately 25 micrometers.

[0015] The heating efficiency, and therefore the extraction efficiency of the substrate, depends not only on the geometry of the elongated susceptor elements, in particular their relative dimensions, but also on their orientation relative to the alternating magnetic field used for induction heating. In this regard, it has been found that the overall heating performance of the elongated susceptor elements improves as the deviation from alignment substantially parallel to the alternating magnetic field used for induction heating decreases. For a substantially parallel alignment, the heating performance is at a maximum.

[0016] Thus, the elongated susceptor element is preferably aligned within the aerosol-forming substrate substantially parallel to a predefined reference axis of the article. Preferably, the predefined reference axis of the article is given by the orientation of the alternating magnetic field provided by the aerosol-generating device with which the article is to be used. More particularly, the predefined reference axis of the article may be defined by the orientation of the magnetic field lines at the location of the elongated susceptor element when the aerosol-generating article is engaged with the device, i.e. may correspond to or may be parallel to the orientation of the magnetic field lines. For example, in the case where the magnetic field lines at the location of the elongated susceptor element in the article in use extend substantially parallel to the longitudinal axis of the article, the predefined reference axis of the article may correspond to the longitudinal axis of the article. Thus, the elongated susceptor element may be aligned within the aerosol-forming substrate substantially parallel to the longitudinal axis of the article. As used herein, the term "substantially parallel" is understood to mean "parallel with a deviation of ±5° from a parallel arrangement".

[0017] The elongated susceptor element does not necessarily need to be aligned perfectly parallel to a predefined reference axis of the article, in particular the orientation of the alternating magnetic field. Even if the elongated susceptor element is aligned within a certain angular range with respect to the predefined reference axis of the article, in particular the longitudinal axis of the article, and more particularly the orientation of the alternating magnetic field, the overall heating performance is still higher than that of a susceptor device having randomly oriented susceptor elements. Advantageously, the elongated susceptor element may be aligned within the aerosol-forming substrate such that the angle between the length dimension of the elongated susceptor element and the predefined reference axis of the article, in particular the longitudinal axis of the article, and more particularly the orientation of the alternating magnetic field when used with an aerosol-generating device providing the alternating magnetic field, is in the range of between +30 degrees and -30 degrees, in particular between +25 degrees and -25 degrees, and more particularly between +10 degrees and -10 degrees.

[0018] In general, the elongated susceptor elements may even be randomly oriented within the aerosol-forming substrate, although the overall heating performance may be lower for the random orientation than for a collection of elongated susceptor elements aligned substantially parallel to the alternating magnetic field used for induction heating. As mentioned above, even for the random orientation, the overall heating performance of the collection of elongated susceptor elements is still higher on statistical average than the overall heating performance of the collection of non-elongated susceptor elements.

[0019] The heating efficiency also depends on the density of the elongated susceptor elements within the aerosol-forming substrate. The higher the density, the higher the heating efficiency. Preferably, the (volume) density of the elongated susceptor elements within the aerosol-forming substrate is in the range of between 0.001 susceptor elements / m3 and 30 susceptor elements / m3, in particular between 0.1 susceptor elements / m3 and 10 susceptor elements / m3. Similarly, the mass density of the elongated susceptor elements within the aerosol-forming substrate may be in the range of between 0.002 mg susceptor mass / m3 and 0.3 mg susceptor mass / m3, in particular between 0.01 mg susceptor mass / m3 and 0.1 mg susceptor mass / m3.

[0020] In general, the susceptor element may have any geometric shape as long as it is elongated. In particular, the elongated susceptor element may have one of an elongated cylindrical shape or an oblate elliptical shape. That is, the elongated susceptor element may have a strip-like shape or a granular shape.

[0021] As an example, the elongated susceptor element may be a fiber element, in particular a chopped fiber element or a ground fiber element. As another example, the elongated susceptor element may be a wire element, a thread element, a granular element, a filament element, or a strip element. Advantageously, the fiber element, the wire element, the granular element, the filament element, or the strip element is made of an inductively heatable material (such as metal fiber, metal wire, or metal thread) that is readily available at low cost.

[0022] As viewed in a plane perpendicular to the length dimension of the susceptor element, the cross-section of the elongated susceptor element may have a circular shape, an oval shape, an elliptical shape, a triangular shape, a rectangular shape, a quadratic shape, or a polygonal shape. If the cross-section is circular, the aforementioned maximum lateral dimension of the elongated susceptor element corresponds to the diameter of the susceptor element, wherein the diameter is at its maximum along the length dimension of the elongated susceptor element. If the cross-section is oval or elliptical, the aforementioned maximum lateral dimension of the susceptor element corresponds to the length of the semi-major axis of the oval or elliptical cross-section, wherein the length is at its maximum along the length dimension of the elongated susceptor element. If the cross-section is quadratic or generally rectangular, the aforementioned maximum lateral dimension of the susceptor element corresponds to the length of the edge / major edge of the quadratic / rectangular cross-section.

[0023] Generally speaking, the term "susceptor element," as used herein, refers to an element comprising a susceptor material that is capable of converting electromagnetic energy into heat when subjected to an alternating magnetic field. This can be the result of at least one of hysteresis losses and eddy currents induced in the susceptor material, depending on the electrical and magnetic properties of the susceptor material. In ferromagnetic or ferrimagnetic susceptor materials, hysteresis losses occur due to the switching of magnetic domains within the material under the influence of the alternating electromagnetic field. If the susceptor material is electrically conductive, eddy currents can be induced. In the case of electrically conductive ferromagnetic or electrically conductive ferrimagnetic susceptors, heat can be generated due to both eddy currents and hysteresis losses.

[0024] Thus, the susceptor material of the elongated susceptor element may generally be at least one of: electrically conductive, and ferromagnetic or ferrimagnetic. In particular, the susceptor material of the elongated susceptor element may be non-conductive, but ferromagnetic or ferrimagnetic. Alternatively, the susceptor material of the elongated susceptor element may be electrically conductive, but neither ferromagnetic nor ferrimagnetic.

[0025] Preferably, the susceptor material of the elongated susceptor element comprises or consists of a metal, such as ferritic iron, or stainless steel, in particular stainless steel grade 410, 420 or 430. Alternatively, the susceptor material of the elongated susceptor element may comprise a ferrimagnetic ceramic.

[0026] In addition to the susceptor material, the elongated susceptor element may also contain a ferromagnetic or ferrimagnetic temperature marker material. While the susceptor material is optimized for heat loss and, therefore, heating efficiency, the temperature marker material is a magnetic (ferromagnetic or ferrimagnetic) material selected to have a Curie temperature that substantially corresponds to a predefined temperature point during the heating process. When the temperature of the susceptor assembly and the aerosol-forming substrate reaches the Curie temperature of the temperature marker material, the magnetic permeability of the temperature marker material drops to unity, causing a change in its magnetic properties from ferromagnetic or ferrimagnetic to paramagnetic. This change in magnetic properties is accompanied by a temporary change in the resistance of the susceptor assembly and a temporary change in the inductance of the induction heating assembly. Therefore, by monitoring the corresponding change in the current passing through the induction heating assembly, which generates the alternating magnetic field that heats the susceptor assembly, it is possible to detect when the temperature marker material has reached its Curie temperature, and therefore, when the predefined temperature point has been reached.

[0027] In particular, the temperature-marking material may be selected to have a Curie temperature that substantially corresponds to a predefined maximum heating temperature of the susceptor device. The maximum desired heating temperature may be defined as the approximate temperature to which the susceptor device should be heated in order to generate an aerosol from the aerosol-forming substrate. However, the maximum desired heating temperature should be sufficiently low to avoid localized overheating or even combustion of the aerosol-forming substrate. Preferably, the Curie temperature of the temperature-marking material should be below the ignition point of the aerosol-forming substrate to be heated.

[0028] The temperature marking material may have a Curie temperature below 500° C., preferably equal to or below 400° C., in particular equal to or below 390° C. For example, the temperature marking material of the elongated susceptor element may have a Curie temperature in the range of between 180° C. and 420° C., in particular between 210° C. and 380° C., preferably between 250° C. and 380° C. Although the temperature marking material is primarily a functional material that provides a temperature marking via its Curie temperature, it may also affect the inductive heating process of the susceptor device.

[0029] The temperature marking material of the elongated susceptor element may comprise or consist of nickel or a nickel alloy. As an example, the temperature marking material of the elongated susceptor element may comprise or consist of a Ni—Fe alloy, in particular a Ni—Fe alloy comprising 75-85 wt.-% Ni and 10-25 wt.-% Fe, more in particular a Ni—Fe alloy comprising one of the following:

[0030] - 79-82 wt% Ni and 13-15 wt% Fe; or

[0031] - 79-82 wt% Ni, 4-6 wt% Mo, less than 1 wt% Si and Mn combined, and 13-15 wt% Fe; or

[0032] 77 wt% Ni, 16 wt% Fe, 5 wt% Cu and 2 wt% of one of Cr and Mo; or 77 wt% Ni, 14 to 15 wt% Fe, 4 wt% Cu and 4 wt% Mo.

[0033] As another example, the temperature marking material may include or may consist of a Fe-Ni-Cr alloy, in particular a Fe-Ni-Cr alloy including one of:

[0034] 50 wt. % Ni, 11 wt. % Cr, the remainder Fe (a commercial alloy available under the trade name Phytherm 210, having a Curie temperature of about 210° C.); or

[0035] 50% by weight of Ni, 10% by weight of Cr, the remainder being Fe (a commercial alloy available under the trade name Phytherm 230, having a Curie temperature of approximately 230° C.); or

[0036] 50% by weight of Ni, 9% by weight of Cr, the remainder being Fe (a commercial alloy available under the trade name Phytherm 260, having a Curie temperature of about 260° C.), or

[0037] 50 wt.-% Ni, 9 wt.-% Cr, up to 1 wt.-% Si and up to 1 wt.-% Mn, the remainder being Fe; or

[0038] 50 wt.-% Ni, 10 wt.-% Cr, up to 1 wt.-% Si and up to 1 wt.-% Mn, the remainder being Fe; or

[0039] 50 wt.-% Ni, 11 wt.-% Cr, up to 1 wt.-% Si and up to 1 wt.-% Mn, the remainder being Fe.

[0040] As yet another example, the temperature marking material of the elongated susceptor element may comprise or consist of a Ni—Fe alloy available from Hitachi under the designation “MS-10”, which has a Ni content of 36.1% by weight and a Curie temperature of 213° C. Similarly, the temperature marking material of the elongated susceptor element may comprise or consist of a Ni—Fe alloy available from Hitachi under the designation “MS-16”, which has a Ni content of 36.4% by weight and a Curie temperature of 221.5° C.

[0041] The susceptor element can be formed such that the susceptor material is at least partially, preferably completely, surrounded or covered by the temperature marking material. In other words, the temperature marking material can be a coating or layer that at least partially, preferably completely, surrounds or covers the susceptor material. Conversely, the susceptor element can be formed such that the temperature marking material is at least partially, preferably completely, surrounded or covered by the susceptor material. In other words, the susceptor material can be a coating or layer that at least partially, preferably completely, surrounds or covers the temperature marking material.

[0042] Advantageously, the temperature marker material and the susceptor material can be tightly coupled to each other. For example, one of the temperature marker material and the susceptor material can be applied, deposited, coated, clad, or welded to the other material. In particular, one of the temperature marker material and the susceptor material can be applied to the other material by spraying, dipping, roller coating, electroplating, or cladding. Any of the configurations described above fall within the term "tightly coupled" as used herein.

[0043] In addition, the elongated susceptor element may include an outer protective coating surrounding the susceptor material and, if present, the temperature marker material. Preferably, the protective coating is an anti-corrosion coating. Advantageously, the protective coating renders the elongated susceptor element resistant to external influences, in particular corrosive influences.

[0044] It is also possible that the susceptor material of the susceptor element itself has a temperature marking function. That is, the elongated susceptor element may comprise a single material that serves as both the susceptor material and the temperature marking material. For example, this single material may be one of the materials mentioned above with respect to the susceptor temperature marking material in addition to the susceptor material.

[0045] As an alternative or in addition to a temperature marking material as part of the elongate susceptor element, the susceptor device may comprise one or more sensitive temperature marking elements in addition to the plurality of elongate susceptor elements.

[0046] Similar to the susceptor element, the one or more temperature marker elements may include or consist of a ferromagnetic or ferrimagnetic temperature marker material. Similar to the temperature marker material of the susceptor element, the ferromagnetic or ferrimagnetic temperature marker material of the one or more temperature marker elements may be selected to have a Curie temperature that substantially corresponds to a predefined temperature point of the heating process, in particular, to a predefined maximum heating temperature of the susceptor device. Thus, the sensitive temperature marker material of the one or more temperature marker elements may have a Curie temperature below 500°C, preferably equal to or below 400°C, and in particular equal to or below 390°C. For example, the temperature marker material of the temperature marker element may have a Curie temperature in the range of between 180°C and 420°C, in particular between 210°C and 380°C, and preferably between 250°C and 380°C.

[0047] The ferromagnetic or ferrimagnetic temperature marking material of the one or more temperature marking elements may be one of the materials disclosed above with respect to the temperature marking material of the susceptor element. In other words, the ferromagnetic or ferrimagnetic temperature marking material of the one or more temperature marking elements may contain nickel or a nickel alloy or may consist of nickel or a nickel alloy. As an example, the temperature marking material of the one or more temperature marking elements may contain or may consist of a Ni-Fe alloy, in particular a Ni-Fe alloy containing 75% to 85% by weight of Ni and 10% to 25% by weight of Fe, more in particular a Ni-Fe alloy comprising one of the following:

[0048] - 79-82 wt% Ni and 13-15 wt% Fe; or

[0049] - 79-82 wt% Ni, 4-6 wt% Mo, less than 1 wt% Si and Mn combined, and 13-15 wt% Fe; or

[0050] - 77 wt% Ni, 16 wt% Fe, 5 wt% Cu and 2 wt% of one of Cr and Mo; or

[0051] 77 wt.-% Ni, 14 to 15 wt.-% Fe, 4 wt.-% Cu and 4 wt.-% Mo.

[0052] As another example, the temperature marking material of the one or more temperature marking elements may include or may consist of a Fe-Ni-Cr alloy, in particular a Fe-Ni-Cr alloy comprising one of:

[0053] 50 wt. % Ni, 11 wt. % Cr, the remainder Fe (a commercial alloy available under the trade name Phytherm 210, having a Curie temperature of about 210° C.); or

[0054] 50% by weight of Ni, 10% by weight of Cr, the remainder being Fe (a commercial alloy available under the trade name Phytherm 230, having a Curie temperature of approximately 230° C.); or

[0055] 50% by weight of Ni, 9% by weight of Cr, the remainder being Fe (a commercial alloy available under the trade name Phytherm 260, having a Curie temperature of about 260° C.), or

[0056] 50 wt.-% Ni, 9 wt.-% Cr, up to 1 wt.-% Si and up to 1 wt.-% Mn, the remainder being Fe; or

[0057] 50 wt.-% Ni, 10 wt.-% Cr, up to 1 wt.-% Si and up to 1 wt.-% Mn, the remainder being Fe; or

[0058] 50 wt.-% Ni, 11 wt.-% Cr, up to 1 wt.-% Si and up to 1 wt.-% Mn, the remainder being Fe.

[0059] As yet another example, the temperature marking material of one or more temperature marking elements may comprise or consist of a Ni—Fe alloy available from Hitachi under the designation “MS-10”, which has a Ni content of 36.1% by weight and a Curie temperature of 213° C. Similarly, the temperature marking material of the elongated susceptor element may comprise or consist of a Ni—Fe alloy available from Hitachi under the designation “MS-16”, which has a Ni content of 36.4% by weight and a Curie temperature of 221.5° C.

[0060] Similar to the susceptor element, the temperature marking element may be dispersed throughout the aerosol-forming matrix.

[0061] Conversely, it is also possible that the susceptor arrangement comprises a single temperature marking element that is arranged in the aerosol-generating article so as to be subjected to the alternating magnetic field provided by an aerosol-generating device with which the aerosol-generating article is to be used.

[0062] In general, the one or more temperature marker elements may be granular temperature marker elements, isodimensional temperature marker elements, flat temperature marker elements, or elongated temperature marker elements, in particular elongated temperature marker elements having the same shape and / or the same dimensions as the elongated susceptor element. In the case where the susceptor device comprises a single temperature marker element, the single temperature marker element may have the shape of, or may be, a strip element, a pin element, a sheet element, a granular element, a sheet element, a mesh element, a thread element, a fiber element, a filament element, or a fine filament element. In the case where the sensor device includes multiple temperature marking elements, the temperature marking element may have the shape of one of a granular element, a wire element, a fiber element, a silk element or a filament element, a spherical or quasi-spherical element, an oblate cylindrical element or an oblate elliptical element, or a thin sheet element or a plate element, or may be one of a granular element, a wire element, a fiber element, a silk element or a filament element, a spherical or quasi-spherical element, an oblate cylindrical element or an oblate elliptical element, or a thin sheet element or a plate element.

[0063] In the case where the temperature marker element has an elongated shape, the temperature marker element may be dispersed throughout the aerosol-forming substrate in a random orientation, within a range of angles, or in an orientation parallel to a predefined reference axis of the article, similar to the elongated susceptor element. In particular, the temperature marker element may be aligned within the aerosol-forming substrate such that the angle between the length dimension of the elongated susceptor element and the predefined reference axis of the article, in particular the longitudinal axis of the article, is in the range of between +30 degrees and -30 degrees, in particular between +25 degrees and -25 degrees, more in particular between +10 degrees and -10 degrees. Again, the predefined reference axis of the article is preferably given by the orientation of the alternating magnetic field provided by the aerosol-generating device with which the article is to be used.

[0064] Similar to the elongated susceptor element, the one or more temperature marking elements may comprise an external protective coating, in particular an external anti-corrosion coating, in order to render the one or more temperature marking elements resistant to external influences, in particular corrosive influences.

[0065] Although the present invention has been described herein with respect to elongated susceptor elements having a length dimension that is greater than any transverse dimension perpendicular to the length dimension (i.e., with respect to 1D elongated susceptor elements having a greater extent in one principal dimension than in the two remaining dimensions perpendicular to the principal dimension), it is equally applicable to susceptor elements having a greater extent in two (perpendicular) principal dimensions than in the remaining dimensions perpendicular to the principal dimensions. Such susceptor elements may also be denoted as 2D elongated susceptor elements. In particular, the present invention is equally applicable to susceptor elements having a length dimension that is greater than the thickness direction and a width dimension, wherein the length dimension may be greater than or substantially similar to the width dimension. More particularly, the present invention is equally applicable to susceptor elements having one of an oblate cylindrical shape (such as a coin), an oblate elliptical shape (such as a lens), or a sheet or plate shape. For these susceptor elements, the same features and advantages as described herein with respect to the (1D) elongated susceptor elements apply equally and can be expressed equally by essentially replacing the term "maximum length dimension of the (1D) elongated susceptor element(s)" with "maximum extent of the (1D) elongated susceptor element(s) in the two principal dimensions" and replacing "maximum lateral dimension of the (1D) elongated susceptor element(s)" with "maximum extent of the (1D) elongated susceptor element(s) in the remaining (non-principal) dimensions".

[0066] As used herein, the term "aerosol-generating article" refers to an article comprising at least one aerosol-forming substrate capable of releasing volatile compounds upon heating in order to form an aerosol. The aerosol-generating article may be a consumable, in particular a consumable that is disposed of after a single use. For example, the article may be an elongated article or a strip-shaped article. The elongated or strip-shaped article may have a shape similar to that of a conventional cigarette. In particular, such an article may have a circular, elliptical, oval, square, rectangular, triangular, or polygonal cross-section. As another example, the article may be a cartridge comprising a liquid aerosol-forming substrate to be heated.

[0067] As used herein, the term "aerosol-forming substrate" refers to a substrate formed of or comprising an aerosol-forming material that is capable of releasing volatile compounds upon heating to generate an aerosol. Preferably, the aerosol-forming substrate is intended to be heated rather than burned to release the volatile compounds that form the aerosol. Thus, such a substrate may be denoted as a heat-not-burn aerosol-forming substrate. Similarly, an aerosol-generating article comprising such an aerosol-forming substrate may be denoted as a heat-not-burn aerosol-generating article.

[0068] In general, the aerosol-forming substrate comprises at least one aerosol-forming agent and at least one sensory material, both of which are volatile when heated. The sensory material may include at least one of a tobacco-containing material, a nicotine-containing material, and a flavoring substance. Examples of suitable aerosol-forming agents are glycerol and propylene glycol. Examples of flavoring substances may be plant extracts and natural or artificial flavorings.

[0069] 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 comprise both a solid component and a liquid component.

[0070] As mentioned above, aerosol forms a matrix and can comprise the tobacco-containing material that contains volatile tobacco flavor compounds, and described volatile tobacco flavor compounds releases from matrix when heating.For example, aerosol forms a matrix and can comprise porous matrix or foam based on tobacco fiber or the filler that comprises cut tobacco material.Especially, aerosol forms a matrix and can comprise reconstituted tobacco material or contain tobacco slurry.Therefore, aerosol generates goods and can be tobacco-containing goods.Alternately or in addition, aerosol forms a matrix and can comprise non-tobacco material.For example, aerosol forms a matrix and can comprise porous matrix or foam based on vegetable material fiber, or the filler that comprises cut vegetable material, or the cellulose fiber or the cellulose-based fiber that comprises flavoring substance.Aerosol forms a matrix and can also comprise other additives and composition, such as nicotine or spices.

[0071] As another example, the article may include a plurality of elongated susceptor elements in combination with an aerosol-forming substrate comprising a nicotine-containing material, organic fibers, a binder, and an aerosol-forming agent. According to yet another example, the article may include a plurality of elongated susceptor elements in contact with a substrate comprising cut tobacco filler. As yet another example, the article may include a plurality of elongated susceptor elements embedded in a gel-like aerosol-forming substrate. In particular, the aerosol-forming substrate may also be a pasty material, a pouch of porous material comprising an aerosol-forming substrate, or loose tobacco, for example, mixed with a gelling agent or adhesive, which may contain common aerosol-forming agents such as glycerol, and which is compressed or molded into a rod.

[0072] Preferably, the aerosol-forming substrate is made of a sheet material. For example, the aerosol-forming substrate can be made of a curled tobacco sheet containing tobacco material, organic fibers, a binder, and an aerosol-forming agent. Alternatively, the aerosol-forming substrate can be made of a sheet material containing nicotine-containing material, organic fibers, a binder, and an aerosol-forming agent. As another alternative, the aerosol-forming substrate can be made of a sheet material containing tobacco cut filler. In this regard, it has been found that if the susceptor element is applied to the aerosol-forming substrate when the aerosol-forming substrate is in the form of a sheet material, the aerosol-generating article is easy to manufacture, particularly with respect to the preferred alignment of the elongated susceptor element relative to a predefined reference axis of the article. This may be the result of a manufacturing process that includes depositing the susceptor element on the outer surface of the sheet material during a primary process (in which the sheet material is produced) or during a secondary process (in which the sheet material is machined and combined with other semi-finished products to obtain the final product). Thus, the elongated susceptor element can ultimately be disposed on or at least partially embedded in the outer surface of the sheet material, near the outer surface of the sheet material. This can be observed even if the sheet material is subsequently machined (e.g., curled and gathered) to form the matrix rods in the final product. As previously described with respect to the elongated susceptor element, one or more temperature marker elements (if present) can also be disposed on or at least partially embedded in the outer surface of the sheet material, near the outer surface of the sheet material.

[0073] Preferably, the aerosol generating article can be a strip-shaped article. In particular, the cylindrical article comprises one or more of the following elements: a distal front rod element, a matrix element, a first tube element, a second tube element, and a filter element. The matrix element preferably comprises at least one aerosol-forming matrix to be heated, and a susceptor device having a plurality of elongated susceptor elements dispersed throughout the matrix. The matrix element can have a length of 10 mm to 14 mm (e.g., 12 mm). The susceptor device can extend along the entire length of the matrix element, or can extend with a length shorter than the length of the matrix element.

[0074] The first tube element is more distal than the second tube element. Preferably, the first tube element is proximal to the matrix element, while the second tube element is proximal to the first tube element and distal to the filter element, that is, between the first tube element and the filter element. At least one of the first tube element and the second tube element may include 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 include a hollow cellulose acetate tube. At least one of the first tube element and the second tube element may have a length of 6 mm to 10 mm (e.g., 8 mm).

[0075] The filter element is preferably used as a mouthpiece, or as part of a mouthpiece together with the second tube element. As used herein, the term "mouthpiece" refers to the portion of the article through which the aerosol leaves the aerosol-generating article. The filter element may have a length of 10 mm to 14 mm (e.g., 12 mm).

[0076] The distal front rod element can be used to cover and protect the distal front end of the matrix element. The distal front rod element can have a length of 3 mm to 6 mm (e.g., 5 mm). The distal front rod element can be made of the same material as the filter element.

[0077] All of the aforementioned elements can be arranged sequentially along the longitudinal axis of the article in the order described above, with the distal front rod element preferably being arranged at the distal end of the article and the filter element preferably being arranged at the proximal end of the article. Each of the aforementioned elements can be substantially cylindrical. In particular, all elements can have the same outer cross-sectional shape and / or size.

[0078] In some embodiments, the strip product of claim 1 is a strip product of the present invention. In some embodiments, the strip product of the present invention is a strip product of the present invention. In some embodiments, the strip product of the present invention is a strip product of the present invention. In some embodiments, the strip product of the present invention is a strip product of the present invention. In some embodiments, the strip product of the present invention is a strip product of the present invention. In some embodiments, the strip product of the present invention is a strip product of the present invention. In some embodiments, the strip product of the present invention is a strip product of the present invention. In some embodiments, the strip product of the present invention is a strip product of the present invention. In some embodiments, the strip product of the present invention is a strip product of the present invention. In some embodiments, the strip product of the present invention is a strip product of the present invention. In some embodiments, the strip product of the present invention is a strip product of the present invention. In some embodiments, the strip product of the present invention is a strip product of the present invention. In some embodiments, the strip product of the present invention is a strip product of the present invention. In some embodiments, the strip product of the present invention is a strip product of the present invention. In some embodiments, the strip product of the present invention is a strip product of the present invention.

[0079] According to another aspect of the present invention, there is provided an aerosol-generating system comprising an aerosol-generating article according to the present invention and as described herein, and an induction-heated aerosol-generating device for use with the aerosol-generating article.

[0080] As used herein, the term "aerosol-generating device" describes an electrically operated device for interacting with an aerosol-generating article to generate an aerosol by heating an aerosol-forming substrate within the article through interaction with an alternating magnetic field provided by the electrically operated device via a susceptor device. Preferably, the aerosol-generating device is a puffing device for generating an aerosol that is directly inhalable by a user through the user's mouth. In particular, the aerosol-generating device is a handheld aerosol-generating device.

[0081] The device may comprise a receiving cavity for removably receiving at least a portion of a respective aerosol-generating article.

[0082] The aerosol generating device may further comprise induction heating means configured and arranged to generate an alternating magnetic field in the receiving cavity so as to inductively heat the susceptor means when the article is received in the cavity.

[0083] To generate the alternating magnetic field, the induction heating device may include at least one induction coil that surrounds at least a portion of the susceptor device during use of the system. The at least one induction coil may be a spiral coil or a flat planar coil, in particular a pancake coil or a curved planar coil. The aerosol-generating device and the aerosol-generating article are preferably configured such that, when the article is received in the aerosol-generating device, the susceptor device is disposed within a cavity of the device, in particular within the interior space of the at least one induction coil, so as to be subjected to the alternating magnetic field. The induction heating device may further include an alternating current (AC) generator. The AC generator may be powered by a power supply of the aerosol-generating device. The AC generator may be operably coupled to the 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 through the at least one induction coil for generating the alternating magnetic field. The AC current may be supplied continuously to the at least one induction coil after activation of the system, or may be supplied intermittently, such as on a puff-by-puff basis. Preferably, the induction heating device includes a DC / AC converter comprising an LC network, wherein the LC network comprises a series connection of a capacitor and an inductor. The DC / AC converter may be connected to a DC power supply.

[0084] The induction heating device is preferably configured to generate a high-frequency magnetic field. As mentioned herein, the frequency of the high-frequency magnetic field may be in the range of 500kHz (kilohertz) to 30MHz (megahertz), in particular 5MHz (megahertz) to 15MHz (megahertz), preferably 5MHz (megahertz) to 10MHz (megahertz).

[0085] The aerosol generating device may further comprise a controller configured to control the operation of the heating process. The controller may be an overall controller of the aerosol generating device, or may be part of the overall controller. The controller may comprise a microprocessor, such as a programmable microprocessor, a microcontroller or an application specific integrated circuit (ASIC), or other electronic circuitry capable of providing control. The controller may comprise further electronic components, such as at least one DC / AC converter and / or a power amplifier, such as a class C power amplifier, a class D power amplifier or a class E power amplifier. In particular, the induction source may be part of the controller.

[0086] The aerosol generating device may further comprise a power source, in particular a DC power source, configured to provide a DC supply voltage and a DC supply current to the induction source. Preferably, the power source is 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 sufficient capacity to allow for continuous aerosol generation for a period of approximately six minutes, or a multiple of six minutes. In another example, the power source may have sufficient capacity to allow for a predetermined number of puffs or discontinuous activation of the induction source.

[0087] Further features and advantages of the aerosol-generating system have been described with respect to the aerosol-generating article and therefore apply equally.

[0088] The present invention is defined in the claims. However, a non-exhaustive list of non-limiting examples is provided below. Any one or more features of these examples may be combined with any one or more features of another example, embodiment or aspect described herein.

[0089] Example Ex1: An aerosol-generating article for use with an induction-heating aerosol-generating device, the article comprising an aerosol-forming substrate and a sensor device, the sensor device being used to heat the aerosol-forming substrate by interaction of the sensor device with an alternating magnetic field provided by the aerosol-generating device, wherein the aerosol-forming substrate comprises at least one aerosol-forming agent and at least one sensory material, the at least one aerosol-forming agent and the at least one sensory material being volatile when heated, wherein the sensor device comprises a plurality of elongated sensor elements comprising sensor material, the plurality of elongated sensor elements being dispersed throughout the aerosol-forming substrate, wherein the ratio of the maximum length dimension of the elongated sensor element to the maximum lateral dimension of the elongated sensor element perpendicular to the (maximum) length dimension is greater than 4.

[0090] Example Ex2: An aerosol-generating article according to Example Ex1, wherein the ratio of the maximum length dimension of the elongated receptor to the maximum transverse dimension of the element perpendicular to the (maximum) length dimension is greater than 10, preferably greater than 20, more preferably greater than 25, even more preferably greater than 30, and most preferably greater than 35.

[0091] Example Ex3: An aerosol-generating article according to any of the preceding examples, wherein the ratio of the maximum length dimension of the elongated sensor element to the maximum transverse dimension perpendicular to the (maximum) length dimension is in the range between 4 and 500, in particular between 10 and 300, preferably between 20 and 200, more preferably between 30 and 100.

[0092] Example Ex4: An aerosol-generating article according to any one of the preceding examples, wherein the maximum length dimension of the elongated susceptor element is in the range between 0.02 μm and 50 mm, in particular between 1 μm and 16 mm, preferably between 0.1 mm and 5 mm.

[0093] Example Ex5: An aerosol-generating article according to any of the preceding examples, wherein the maximum transverse dimension of the elongated susceptor element is in the range between 0.005 and 500 micrometers, in particular between 0.1 and 150 micrometers, preferably between 20 and 100 micrometers.

[0094] Example Ex6: An aerosol-generating article according to any one of the preceding examples, wherein the maximum transverse dimension of the elongated susceptor element is equal to or less than 500 microns, particularly equal to or less than 100 microns, preferably equal to or less than 10 microns, more preferably equal to or less than 1 micron.

[0095] Example Ex7: An aerosol-generating article according to any one of Examples Ex1 to Ex6, wherein the elongated susceptor elements are randomly oriented within the aerosol-forming substrate.

[0096] Example Ex8: An aerosol-generating article according to any one of Examples Ex1 to Ex6, wherein the elongated susceptor element is aligned within the aerosol-forming substrate substantially parallel to a predefined reference axis of the article, in particular parallel to the length axis of the article.

[0097] Example Ex9: An aerosol-generating article according to any one of Examples Ex1 to Ex6, wherein the elongated sensor element is aligned within the aerosol-forming substrate such that the angle between the length dimension of the elongated sensor element and a predefined reference axis of the article, in particular the length axis of the article, is in the range between +30 degrees and -30 degrees, in particular between +25 degrees and -25 degrees, more in particular between +10 degrees and -10 degrees.

[0098] Example Ex10: An aerosol-generating article according to any of the preceding examples, wherein the density of the elongated sensor elements within the aerosol-forming substrate is in the range between 0.001 sensor elements / mm3 and 30 sensor elements / mm3, in particular between 0.1 sensor elements / mm3 and 10 sensor elements / mm3; or wherein the mass density of the elongated sensor elements within the aerosol-forming substrate is in the range between 0.002 mg sensor mass / mm3 and 0.3 mg sensor mass / mm3, in particular between 0.01 mg sensor mass / mm3 and 0.1 mg sensor mass / mm3.

[0099] Example Ex11: The aerosol-generating article according to any of the preceding examples, wherein the elongated susceptor element has one of an elongated cylindrical shape or a prolate elliptical shape.

[0100] Example Ex12: The aerosol-generating article according to any one of the preceding examples, wherein the elongated susceptor element is one of a fiber element, a thread element, a string element, a particle element, or a strip element, in particular a chopped fiber element or a milled fiber element.

[0101] Example Ex13: An aerosol-generating article according to any one of the preceding examples, wherein the cross-section of the elongated susceptor element in a plane perpendicular to the length dimension of the susceptor element has a circular shape or an oval shape or an elliptical shape or a triangular shape or a rectangular shape or a quadratic shape or a polygonal shape.

[0102] Example Ex 14: The aerosol-generating article according to any of the preceding examples, wherein the susceptor material of the elongated susceptor element is at least one of: electrically conductive, and ferromagnetic or ferrimagnetic.

[0103] Example Ex15: An aerosol-generating article according to any of the preceding examples, wherein the susceptor material of the elongated susceptor element comprises or consists of a metal or a ferrimagnetic ceramic, the metal being, for example, ferritic iron, or stainless steel, in particular grade 410, 420 or 430 stainless steel.

[0104] Example Ex 16: The aerosol-generating article according to any one of the preceding examples, wherein the elongated susceptor element comprises, in addition to the susceptor material, a ferromagnetic or ferrimagnetic temperature marking material.

[0105] Example Ex17: An aerosol-generating article according to example Ex16, wherein the temperature marking material of the elongated susceptor element comprises or consists of nickel or a nickel alloy.

[0106] Example Ex18: An aerosol-generating article according to any one of Examples Ex16 to Ex17, wherein the temperature marking material of the elongated susceptor element has a Curie temperature in the range between 180°C and 420°C, in particular between 210°C and 380°C, preferably between 250°C and 380°C.

[0107] Example Ex19: An aerosol-generating article according to any one of Examples Ex16 to Ex18, wherein the susceptor material is surrounded by the temperature marking material.

[0108] Example Ex20: An aerosol-generating article according to any one of the preceding examples, wherein the elongated susceptor element comprises an outer protective coating surrounding the susceptor material and the temperature marking material, if present.

[0109] Example Ex21: The aerosol-generating article according to any of the preceding examples, wherein the susceptor device further comprises, in addition to the plurality of elongated susceptor elements, one or more temperature marking elements comprising a ferromagnetic or ferrimagnetic temperature marking material.

[0110] Example Ex22: An aerosol-generating article according to Example Ex21, wherein the temperature marking element is dispersed throughout the aerosol-forming substrate.

[0111] Example Ex23: An aerosol-generating article according to any one of Examples Ex21 or Ex22, wherein the temperature marking material of the one or more temperature marking elements comprises or consists of nickel or a nickel alloy.

[0112] Example Ex24: An aerosol-generating article according to any one of Examples Ex21 to Ex23, wherein the temperature marking material of the one or more temperature marking elements has a Curie temperature in the range between 180°C and 420°C, in particular between 210°C and 380°C, preferably between 250°C and 380°C.

[0113] Example Ex25: An aerosol-generating article according to any one of Examples Ex21 to Ex24, wherein the one or more temperature marking elements comprise an outer protective coating.

[0114] Example Ex26: An aerosol-generating article according to any one of Examples Ex21 to Ex25, wherein the one or more temperature marking elements are particulate temperature marking elements or isodimensional temperature marking elements or flat temperature marking elements or elongated temperature marking elements, in particular elongated temperature marking elements having the same shape and / or the same size as the elongated sensor element.

[0115] Example Ex27: An aerosol-generating article according to any of the preceding examples, wherein the aerosol-forming substrate is made of a sheet material, and wherein the elongated susceptor element is disposed on an outer surface of the sheet material or is at least partially embedded in the sheet material near an outer surface of the sheet material.

[0116] Example Ex28: An aerosol-generating system comprising an aerosol-generating article according to any one of the preceding examples, and an induction-heated aerosol-generating device for use with the article.

[0117] Examples will now be further described with reference to the accompanying drawings, in which:

[0118] Figure 1 schematically illustrates an exemplary embodiment of an inductively heatable aerosol-generating article according to the present invention, the inductively heatable aerosol-generating article comprising a susceptor arrangement having a plurality of elongate susceptor elements;

[0119] Figure 2 Schematically shows the Figure 1 Exemplary embodiments of an aerosol-generating system for an aerosol-generating article;

[0120] Figure 3 Shown according to Figure 1 Details of the sensor device of the product;

[0121] Figure 4 shows details of another embodiment of a susceptor device;

[0122] Figure 5 shows details of yet another embodiment of a susceptor device;

[0123] Figure 6 shows details of yet another embodiment of a susceptor device;

[0124] Figure 7 Details of an alternative embodiment of an elongated susceptor element are shown;

[0125] Figure 8 shows details of another alternative embodiment of the elongated susceptor element; and

[0126] Figure 9 Shown according to Figure 1 Details of the matrix element of the article.

[0127] Figure 1An exemplary embodiment of an inductively heatable aerosol-generating article 100 according to the present invention is schematically illustrated (not to scale). The aerosol-generating article 100 is a substantially strip-shaped consumable product comprising five elements arranged in sequence in coaxial alignment: a distal front rod element 150, a matrix element 110, a first tube element 140, a second tube element 145, and a filter element 160. The distal front rod element 150 is disposed at the distal end 102 of the article 100 to cover and protect the distal front end of the matrix element 110, while the filter element 160 is disposed at the proximal end 103 of the article 100. Both the distal front rod element 150 and the filter element 160 may be made of the same filter material. The filter element 160 is preferably used as a mouthpiece, particularly as part of a mouthpiece together with the second tube element 145. The filter element may have a length of 10 to 14 mm (e.g., 12 mm), and the distal front rod element 150 may have a length of 3 to 6 mm (e.g., 5 mm). Each of the first and second tube elements 140, 145 is a hollow cellulose acetate tube having a central air passage 141, 146, wherein the cross-section of the central air passage 146 of the second tube element 145 is larger than the cross-section of the central air passage 141 of the first tube element 140. The first and second tube elements 140, 145 may have a length of 6 to 10 mm (e.g., 8 mm). The substrate element 110 comprises an aerosol-forming substrate 130 to be heated and a susceptor arrangement 120 for heating the substrate 130. According to the present invention, the susceptor arrangement 120 comprises a plurality of elongated susceptor elements 121 comprising a ferromagnetic or ferrimagnetic susceptor material, the plurality of elongated susceptor elements being dispersed throughout the aerosol-forming substrate 130 to achieve uniform heating of the substrate 130. The substrate element 110 may have a length of 10 to 14 mm (e.g., 12 mm). Each of the aforementioned elements 150, 110, 140, 145, 160 may be substantially cylindrical. In one embodiment, the strip-shaped article is made of a plurality of outer packagings, such as a rod element 150, a matrix element 110 and a first tube element 140. In another embodiment, the rod element 150, a matrix element 110 and a first tube element 140 are made of a plurality of outer packagings, such as a rod element 150, a matrix element 110 and a first tube element 140. In another embodiment, the rod element 150, a matrix element 110 and a first tube element 140 are made of a plurality of outer packagings, such as a rod element 150, a matrix element 110 and a first tube element 140. In another embodiment, the rod element 150, a matrix element 110 and a first tube element 140 are made of a plurality of outer packagings, such as a rod element 150, a matrix element 110 and a first tube element 140. In another embodiment, the rod element 150, a matrix element 110 and a first tube element 140 are made of a plurality of outer packagings, such as a rod element 150, a matrix element 110 and a first tube element 140. In another embodiment, the rod element 150, a matrix element 110 and a first tube element 140 are made of a plurality of outer packagings, such as a rod element 150, a matrix element 110 and a first tube element 140. In another embodiment, the rod element 150, a matrix element 110 and a first tube element 140 are made of a plurality of outer packagings, such as a paperThe wrappers 171 , 172 may also include an adhesive that adheres the overlapping free ends of the wrappers to each other.

[0128] like Figure 2 As shown in FIG, an aerosol-generating article 100 is configured for use with an induction-heated aerosol-generating device 10. The device 10 and the article 100 together form an aerosol-generating system 1 according to the present invention. The aerosol-generating device 10 comprises a cylindrical receiving cavity 20 defined within a proximal portion 12 of the device 10 for receiving at least a distal portion of the article 100 therein. The device 10 further comprises an induction heating device comprising an induction coil 30 for generating a high-frequency alternating magnetic field within the cavity 20. In this embodiment, the induction coil 30 is a helical coil circumferentially surrounding the cylindrical receiving cavity 20. Due to the cylindrical shape of the helical coil 30, the alternating magnetic field in the cavity is substantially uniform within the space enclosed by the helical coil 30, with the magnetic field lines extending substantially parallel to the longitudinal axis of the cavity 20. The induction coil 30 is arranged such that when the article 100 is inserted into the cavity 20 of the device 10, the substrate portion 110 of the article 100, including the susceptor device 120, is exposed to the alternating magnetic field. Thus, when the induction heating device is activated, the susceptor element 121 of the susceptor device 120 heats up due to eddy currents and / or hysteresis losses caused by the alternating magnetic field, depending on the magnetic and electrical properties of the susceptor material of the susceptor element 121. The susceptor device 120 is heated until a temperature sufficient to evaporate the aerosol-forming substrate 130 is reached. As a result, volatile compounds are released from the aerosol-forming substrate 130 in the substrate element 110 to form an aerosol, which can be drawn towards the proximal end 103 of the article 100 through the first and second tube elements 140, 145 and the filter element 160. Within the distal portion 13, the aerosol generating device 10 further comprises a DC power supply 40 and a controller 50 (only in the case of Figure 2 In addition to the induction coil 30, the induction heating device is preferably at least partially an integrated part of the controller 50.

[0129] Figure 3 Shown in Figure 1Detailed view (not drawn to scale) of a portion of a substrate element 110 used within an aerosol-generating article 100 is shown in FIG. As described above, the substrate element 110 comprises a plurality of elongated susceptor elements 121, i.e., susceptor elements having a greater extent in one principal dimension than in the two remaining dimensions. In the present embodiment, the elongated susceptor elements 121 are chopped fiber elements having a substantially cylindrical shape. According to the present invention, it has been found that heating efficiency, and therefore substrate extraction efficiency, is particularly enhanced if the susceptor elements have an elongated shape (i.e., a shape in which the length dimension of the susceptor element is predominantly greater than any transverse dimension perpendicular to the length dimension). As further explained above, the enhanced heating efficiency is due to the fact that the strength of the demagnetizing field induced in the susceptor elements when exposed to the external alternating magnetic field of an induction heating device is enhanced for elongated shapes compared to, for example, spherical shapes. The heating efficiency of a multi-element susceptor device is higher the more elements are aligned along their length dimension parallel to the external alternating magnetic field of the induction heating device.

[0130] The heating efficiency and thus the extraction efficiency of the matrix is ​​particularly enhanced if the ratio of the maximum length dimension of the elongated susceptor element to the maximum transverse dimension of the elongated susceptor element perpendicular to the length dimension is greater than 4, in particular greater than 10, preferably greater than 20, more preferably greater than 25. Figure 1 and Figure 3 In an embodiment of the present invention, the chopped fiber element has a maximum length dimension L in the range between 0.8 mm and 1.2 mm (average of about 1 mm) and a maximum transverse dimension T (i.e., diameter T) perpendicular to the length dimension L of about 25 microns. Figure 1 、 2 In the embodiments shown in Figures 1 and 3, the ratio of the maximum length dimension L to the maximum transverse dimension T of the elongated susceptor elements 121 (shape factor) averages about 40, which is well above the preferred threshold of 4.

[0131] As previously mentioned, heating efficiency is at a maximum if the elongated susceptor elements 121 are all aligned parallel to the orientation M of the alternating magnetic field. Figure 1 and Figure 3 The elongated susceptor elements 121 within the matrix element 110 shown in FIG. 1 are all substantially parallel to a predefined reference axis of the article (here, the length axis 101 of the article 100, which is defined in accordance with FIG. Figure 1 The product 100 is as follows Figure 2 When the aerosol generating device shown in FIG is engaged, the orientation M of the magnetic field lines at the location of the substrate element 110 within the cavity 20 is aligned along their length dimension (coinciding).

[0132] The elongated susceptor element 121 does not necessarily need to be aligned perfectly parallel to the length axis 101 of the article 100 and the orientation M of the magnetic field lines at the location of the matrix element 110 within the cavity 20, respectively. Figure 4 As shown in , even when aligned within a certain range of angles about the length axis 101 of the article, the overall heating performance is still higher than that of a susceptor device with randomly oriented susceptor elements. Figure 4 As shown in , the elongated susceptor element 121 may advantageously be aligned within the aerosol-forming substrate 130 such that the angle β between the length dimension of the elongated susceptor element and a predefined reference axis of the article, in particular the length axis 101 of the article 100, is in the range between +30 degrees and -30 degrees, in particular between +25 degrees and -25 degrees, more in particular between +10 degrees and -10 degrees.

[0133] However, when considering a collection of susceptor elements, even if the elongated susceptor elements 121 are not all parallel or aligned within a certain angular range, but rather Figure 5 Even when randomly oriented as shown in FIG, the overall heating performance of the collection of elongated susceptor elements 121 is still higher than the overall heating performance of the collection of isodimensional susceptor elements on a statistical average. Thus, in any case, the overall heating performance of the proposed susceptor device 120 of elongated susceptor elements 121 is higher than that of a similar configuration of isodimensional susceptor elements, regardless of whether the elongated susceptor elements are dispersed throughout the substrate in a random orientation, within a certain range of angles, or in an orientation parallel to the alternating magnetic field used for induction heating.

[0134] In addition to the plurality of elongated susceptor elements 121, according to Figure 1-6The susceptor device 120 of the embodiment shown in FIGURE 1 also includes a plurality of temperature marker elements 122 in the form of chopped fiber elements similar to the chopped fiber elements forming the elongated susceptor element 121. The temperature marker elements 122 comprise a ferromagnetic temperature marker material selected to have a Curie temperature substantially corresponding to the predefined maximum heating temperature of the susceptor device 120. When the temperature of the susceptor device 120 and the aerosol-forming substrate 130 reaches the Curie temperature of the temperature marker material, the magnetic permeability of the temperature marker material drops to unity, causing a change in its magnetic properties from ferromagnetic to paramagnetic. This change in magnetic properties is accompanied by a temporary change in the resistance of the susceptor device 120, as well as a temporary change in the inductance of the induction heating device. Thus, by monitoring the corresponding change in the current flowing through the induction heating device of the device 10, it is possible to detect when the temperature marker material has reached its Curie temperature, and therefore when the predefined temperature point has been reached. Advantageously, the Curie temperature is below 500° C., in particular equal to or below 400° C., more in particular equal to or below 390° C., in order to avoid local overheating or even burning of the aerosol-forming substrate 130. For example, the temperature marking material of the temperature marking element may have a Curie temperature in the range of between 180° C. and 420° C., in particular between 210° C. and 380° C., preferably between 250° C. and 380° C. Preferably, the ferromagnetic or ferrimagnetic temperature marking material of the temperature marking element 122 may comprise nickel or a nickel alloy or may consist of nickel or a nickel alloy. As an example, the temperature marking material of one or more temperature marking elements may comprise or may consist of a Ni—Fe alloy, in particular a Ni—Fe alloy comprising 75 wt.-% to 85 wt.-% Ni and 10 wt.-% to 25 wt.-% Fe. As can be seen from Figure 3-6 It is further seen that the temperature marking element 122 can be similar to the sensor element 121, with random orientation ( Figure 5 ) or within a certain angle range ( Figure 4 ) or parallel to the orientation of the alternating magnetic field for induction heating ( Figure 3 and Figure 6 ) are dispersed throughout the aerosol-forming matrix 130.

[0135] As Figure 1-5 As an alternative to the temperature marking element 122 shown, the susceptor element itself may comprise a ferromagnetic or ferrimagnetic temperature marking material having a Curie temperature selected to correspond to a predefined maximum heating temperature of the susceptor device. Figure 7As shown in FIG, the elongated susceptor element 321 can be formed as a fiber element having a susceptor material 323 forming a fiber core surrounded by a temperature marking material 324. That is, the temperature marking material 324 can be a coating or layer surrounding the susceptor material 323. Advantageously, the temperature marking material 324 and the susceptor material 323 are closely coupled to each other. For example, the temperature marking material 324 can be applied to the susceptor material 323, such as by dip coating. Figure 7 As further shown in FIG, the elongated susceptor element 321 may include an outer protective coating 325 surrounding the susceptor material 323 and the temperature marking material 324. Preferably, the protective coating 325 is an anti-corrosion coating that renders the susceptor element 321 resistant to external influences, particularly corrosive influences.

[0136] Instead of Figure 1-5 As shown in FIG1 , the susceptor device 220 may include a plurality of susceptor elements 221 in the form of thread elements or filament elements. Figure 6 As shown in . Figure 3 Similarly, the thread element or filament element is arranged substantially parallel to the length axis 201 of the article, which in turn coincides with the orientation M of the magnetic field lines at the location of the substrate element when used with an aerosol generating device. The thread element or filament element may extend along the entire length dimension of the substrate element.

[0137] As an alternative to fiber elements, thread elements or filament elements, the susceptor device may comprise a plurality of elongated susceptor elements 421 in the form of particle elements. Figure 8 An exemplary embodiment of such a granular element is shown. The granular susceptor element 421 has an oblong oval shape with a length dimension L of approximately 4.5 mm and a maximum transverse dimension T of 1 mm, i.e., a form factor of approximately 4.5. The susceptor element 421 may be made of, for example, a ferrimagnetic ceramic material having a Curie temperature below 400°C. The granular susceptor elements 421 may be dispersed throughout the aerosol-forming substrate in a random orientation or in an orientation M within a range of angles or parallel to the alternating magnetic field used for induction heating.

[0138] Figure 9 Shown included in the Figure 1100, including a perspective view of a portion of the matrix element 110 in the article 100, including a detailed view (lower right) of the internal structure of the portion, particularly the structure of the aerosol-forming matrix 130 and the susceptor device 120. As can be seen from both the perspective view and the detailed view, the aerosol-forming matrix 130 is made of a sheet material. For example, the aerosol-forming matrix 130 may be made of a rolled tobacco sheet containing tobacco material, organic fibers, a binder, and an aerosol-forming agent that has been aggregated into the cylindrical shape of the matrix element 110. As can be further seen from the detailed view, the elongated susceptor element 121 and the temperature marker element 122 are disposed on the outer surface of the sheet material, and even though the sheet material is rolled and aggregated, the elongated susceptor element and the temperature marker element are still visible. This may be the result of a manufacturing process that includes depositing the susceptor element 121 and the temperature marker element 122 on the outer surface of the sheet material during a primary process (in which the sheet material is produced) or during a secondary process (in which the sheet material is machined). In this regard, it has been found that preferred alignment of the elongate susceptor element 121 and the temperature marking element 122 relative to a predefined reference axis of the article (here the length axis 101 of the final article 100) is particularly easy to achieve if the elongate susceptor element 121 and the temperature marking element 122 are applied to the aerosol-forming substrate 130 when the aerosol-forming substrate is in the form of a sheet material.

[0139] For the purpose of this specification and the appended claims, unless otherwise indicated, all numbers representing amounts, quantities, percentages, etc. should be understood to be modified by the term "about" in all cases. Moreover, all ranges include the disclosed maximum and minimum points, and include any intermediate ranges therein that may be specifically listed or may not be listed in this article. Therefore, in this context, the number A is understood to be 5% of A±A. In this context, the number A can be regarded as including the numerical value within the general standard error for the measurement of the attribute modified by the number A. In some cases used in the appended claims, the number A can deviate from the percentages listed above, provided that the amount of A deviation does not substantially affect the basic characteristics and novel features of the invention claimed. Moreover, all ranges include the disclosed maximum and minimum points, and include any intermediate ranges therein that may be specifically listed or may not be listed in this article.

Claims

1. An aerosol-generating article for use with an induction-heated aerosol-generating device, the article comprising an aerosol-forming substrate and susceptor means for heating the aerosol-forming substrate by interaction of the susceptor means with an alternating magnetic field provided by the aerosol-generating device, wherein the aerosol-forming substrate comprises at least one aerosol-forming agent and at least one sensory material, the at least one aerosol-forming agent and the at least one sensory material being volatilizable when heated, wherein the aerosol-forming substrate is a solid aerosol-forming substrate, wherein the susceptor means comprises a plurality of elongate susceptor elements comprising a susceptor material, the plurality of elongate susceptor elements being dispersed throughout the aerosol-forming substrate, wherein the elongated susceptor element is one of a fiber element or a silk element or a thread element or a particle element or a strip element, the fiber element being in particular a chopped fiber element or a milled fiber element, wherein a ratio of a maximum length dimension of the elongated susceptor element to a maximum transverse dimension of the elongated susceptor element perpendicular to the length dimension is greater than 4.

2. An aerosol-generating article according to claim 1, wherein the ratio of the maximum length dimension to the maximum transverse dimension of the elongate susceptor element is greater than 10, preferably greater than 20, more preferably greater than 25, even more preferably greater than 30, and most preferably greater than 35.

3. An aerosol-generating article according to any one of the preceding claims, wherein the ratio of the maximum length dimension to the maximum transverse dimension of the elongate susceptor element is in the range between 4 and 500, in particular between 10 and 300, preferably between 20 and 200, more preferably between 30 and 100.

4. An aerosol-generating article according to any one of the preceding claims, wherein the maximum length dimension of the elongate susceptor element is in the range between 0.02 micrometers and 50 millimeters, in particular between 1 micrometer and 16 millimeters, preferably between 0.1 millimeters and 5 millimeters.

5. An aerosol-generating article according to any one of the preceding claims, wherein the maximum transverse dimension of the elongate susceptor element is in the range of between 0.005 μm and 500 μm, in particular between 0.1 μm and 150 μm, preferably between 20 μm and 100 μm; or wherein the maximum transverse dimension of the elongate susceptor element is equal to or less than 500 μm, in particular equal to or less than 100 μm, preferably equal to or less than 10 μm, more preferably equal to or less than 1 μm.

6. An aerosol-generating article according to any one of the preceding claims, wherein the elongate susceptor elements are randomly oriented within the aerosol-forming substrate; or wherein the elongate susceptor element is aligned within the aerosol-forming substrate substantially parallel to a predefined reference axis of the article, in particular parallel to the length axis of the article; or wherein the elongated susceptor element is aligned within the aerosol-forming substrate such that the angle between the length dimension of the elongated susceptor element and a predefined reference axis of the article, in particular the length axis of the article, is in the range between +30 degrees and -30 degrees, in particular between +25 degrees and -25 degrees, more in particular between +10 degrees and -10 degrees.

7. An aerosol-generating article according to any of the preceding claims, wherein the density of the elongate susceptor elements within the aerosol-forming substrate is in the range between 0.001 susceptor elements / mm3 and 30 susceptor elements / mm3, in particular between 0.1 susceptor elements / mm3 and 10 susceptor elements / mm3; or wherein the mass density of the elongate susceptor elements within the aerosol-forming substrate is in the range between 0.002 mg susceptor mass / mm3 and 0.3 mg susceptor mass / mm3, in particular between 0.01 mg susceptor mass / mm3 and 0.1 mg susceptor mass / mm3.

8. An aerosol-generating article according to any one of the preceding claims, wherein the susceptor material of the elongate susceptor element is at least one of: electrically conductive, and ferromagnetic or ferrimagnetic.

9. An aerosol-generating article according to any one of the preceding claims, wherein the elongate susceptor element comprises, in addition to the susceptor material, a ferromagnetic or ferrimagnetic temperature marking material.

10. An aerosol-generating article according to claim 9, wherein the temperature marking material of the elongate susceptor element has a Curie temperature in the range between 180°C and 420°C, in particular between 210°C and 380°C, preferably between 250°C and 380°C.

11. An aerosol-generating article according to any one of the preceding claims, wherein in addition to the plurality of elongate susceptor elements, the susceptor arrangement further comprises one or more temperature marking elements, the one or more temperature marking elements comprising a ferromagnetic or ferrimagnetic temperature marking material.

12. An aerosol-generating article according to claim 11, the temperature marking element being dispersed throughout the aerosol-forming substrate.

13. An aerosol-generating article according to claim 11 or 12, wherein the one or more temperature marking elements comprise an outer protective coating.

14. An aerosol-generating article according to any one of claims 11 to 13, wherein the one or more temperature marking elements are particulate temperature marking elements or isodimensional temperature marking elements or flat temperature marking elements or elongated temperature marking elements, in particular elongated temperature marking elements having the same shape and / or the same size as the elongated susceptor element.

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