Method and apparatus for applying elongated susceptor elements to an aerosol-forming substrate - Patent Application 20070122997

Abstract

The present invention relates to a method and apparatus for applying elongated susceptor elements to an aerosol-forming substrate for use in an inductively heatable aerosol-generating article, the method comprising the steps of providing an aerosol-forming substrate in the form of a sheet material, providing elongated susceptor elements, feeding the elongated susceptor elements onto a belt conveyor system, transporting the elongated susceptor elements on the conveyor belt towards a discharge end of the belt conveyor system, the conveyor belt returning around a magnetic head pulley that generates a magnetic field, the elongated susceptor elements moving around the magnetic head pulley and being attracted and aligned along the magnetic field, and then, upon exiting the magnetic field, the elongated susceptor elements being discharged and conveyed in alignment from the conveyor belt at the discharge end, and depositing the elongated susceptor elements discharged from the discharge end of the belt conveyor system onto a major surface of the sheet material, particularly under the influence of gravity.

Description

[Technical Field]

[0001] The present disclosure relates to a method for applying elongated susceptor elements to an aerosol-forming substrate for use in an inductively heatable aerosol-generating article. The present disclosure further relates to an apparatus for applying elongated susceptor elements to an aerosol-forming substrate, particularly for use in a method according to the present disclosure. [Background technology]

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

[0003] Depending on the type of substrate and the shape of the article, different configurations of susceptor element / susceptor arrangements are known. As an 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. While solid susceptor elements are low-cost and readily available, they form a single central heat source, which can result in 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 region of the substrate portion is heated only indirectly by heat conduction across adjacent substrate layers. In particular, high-temperature gradients can overheat the inner region of the substrate portion near the susceptor element, while the temperature of the peripheral region of the substrate portion may be too low to volatilize the substrate. Furthermore, the heating efficiency of this configuration is highly sensitive to the proper positioning of the susceptor element within the substrate. All of this can result in suboptimal utilization of the aerosol-forming substrate. Alternatively, articles have been proposed that include spherical or quasi-spherical susceptor particles uniformly intercepted throughout the aerosol-forming substrate. While leading to more uniform heating of the substrate, the heating efficiency of this susceptor configuration is limited, which can also affect extraction efficiency.

[0004] It would therefore be desirable to have an inductively heatable aerosol-forming substrate and an apparatus for producing such an aerosol-forming substrate that has the advantages of the prior art solutions but reduces their limitations, and in particular, it would be desirable to have an aerosol-forming substrate that provides for more efficient heating and utilization of the aerosol-forming substrate. Summary of the Invention

[0005] According to one aspect of the present disclosure, a method for applying elongated susceptor elements to an aerosol-forming substrate for use in an inductively heatable aerosol-generating article is provided. The method includes providing an aerosol-forming substrate in the form of a sheet material and providing elongated susceptor elements. The provided elongated susceptor elements are then fed to a belt conveyor system including a conveyor belt. The elongated susceptor elements are then transported on the conveyor belt toward the discharge end of the belt conveyor system, where the conveyor belt returns around a magnetic head pulley. The magnetic head pulley generates a magnetic field that attracts and aligns the elongated susceptor elements moving around the magnetic head pulley along the magnetic field. Thereafter, upon exiting the magnetic field, the elongated susceptor elements are discharged from the conveyor belt at the discharge end at least partially aligned with respect to the direction of movement. The at least partially aligned elongated susceptor elements discharged from the discharge end of the belt conveyor system are then deposited on a major surface of the sheet material, particularly under the influence of gravity. The sheet material may be provided as a finite sheet of material or as a continuous substrate sheet.

[0006] As used herein, the term "elongated susceptor element" refers to a susceptor element having a greater extent in one major dimension than in two remaining dimensions perpendicular to the major dimension. Thus, an elongated susceptor element may also be referred to as a 1D-elongated susceptor element (synonymous with one-dimensionally elongated susceptor element) or a quasi-1D susceptor element (synonymous with quasi-one-dimensional 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 specifically, a 1D-elongated susceptor element may be an elongated susceptor element or a spheroidal susceptor element.

[0007] Although the present invention is described herein with respect to elongated susceptor elements having a length dimension greater than any transverse dimension perpendicular to the length dimension, i.e., 1D-elongated susceptor elements greater in one major dimension than in two remaining dimensions perpendicular to the major dimension, this definition equally applies to susceptor elements having two (perpendicular) major dimensions greater than the remaining dimensions perpendicular to the major dimension. Such susceptor elements may also be referred to as 2D-elongated susceptor elements. In particular, the present invention equally applies to susceptor elements having a width dimension greater than the length and thickness dimensions, and the length dimension may be greater than or substantially similar to the width dimension. More specifically, the present invention equally applies to susceptor elements having one of the following shapes: an obtuse cylindrical shape, such as a coin shape, an obtuse elliptical shape, such as a lens shape, or a flake or plate shape. For these susceptor elements, the same features and advantages described herein with respect to (1D-) elongated susceptor elements apply equally and can essentially be expressed similarly by replacing the term "maximum length dimension of the (1D-) elongated susceptor element" with "maximum dimension in the two major dimensions of the 2D-elongated susceptor element" and "maximum transverse dimension of the (1D-) elongated susceptor element" with "maximum dimension in the remaining (non-major) direction of the 2D-elongated susceptor element".

[0008] Compared to a single solid susceptor element, the use of multiple elongated susceptor elements distributed throughout the aerosol-forming substrate advantageously results in a more uniform heat distribution across the substrate without any significant temperature gradients across different substrate regions. Furthermore, if 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 containing multiple susceptor elements distributed therein exhibits an increased equivalent thermal conductivity compared to a substrate without susceptor elements or having only a single solid susceptor element. Furthermore, to achieve a uniform heat distribution, the proposed susceptor arrangement is less sensitive to the positioning of the susceptor elements compared to a single solid susceptor element.

[0009] Most importantly, it has been found that the geometry of the susceptor element, particularly its relative dimensions, has a significant impact on heating efficiency and, therefore, substrate extraction efficiency. In this regard, it has been found that susceptor elements with elongated shapes are less prone to demagnetization effects than susceptor elements with more equidimensional dimensions, 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 is progressively magnetized. As the external magnetic field increases, the internal magnetization also increases. This process continues until the magnetization reaches the magnetic saturation point of the material, beyond which no further magnetization occurs. As a result, the magnetization of the susceptor element causes a buildup of magnetic charge density at both ends of the susceptor element, as seen in the direction of the external magnetic field. As a result, the susceptor element generates a magnetic field that causes self-interaction with the material. This magnetic field is along the same direction as the external magnetic field but at a point opposite to it, and is therefore called a demagnetizing field. The demagnetization field depends on the geometry of the susceptor element but not its absolute dimensions. When a susceptor element responds to an external magnetic field change, the demagnetization field is generally assumed to be proportional to the magnetization in each direction, related by a geometrically dependent proportionality constant known as the demagnetization factor. The demagnetization factor depends not only on the shape of the susceptor element but also on its relative orientation with respect to the external magnetic field. To this extent, it has been found that an external magnetic field running through an elongated susceptor element, such as a susceptor element having the shape of a fiber or thin rod with a length dimension significantly greater than any transverse dimension perpendicular to the length dimension, generates a weak or negligible demagnetization field compared to a non-elongated (similarly sized) susceptor element, such as a spherical or quasi-spherical susceptor element. This is intuitively understandable, since in properly aligned elongated susceptor elements, the magnetic charge densities accumulated at both ends of the susceptor element are spatially separated from each other. This causes the demagnetizing field to have a significantly reduced strength and therefore less effect on the magnetizing field, which is the source of power loss. As a result, power loss and therefore heating efficiency is greater in elongated susceptor elements compared to non-elongated (of equal dimensions) susceptor elements, such as spherical or quasi-spherical susceptor elements.This is especially true when the magnetic field orientation is substantially parallel to the length dimension of the elongated susceptor elements, and in this configuration, heating performance is maximized. However, it has been found that the elongated susceptor elements do not necessarily need to be aligned perfectly parallel to the external magnetic field direction. Even if the susceptor elements are arranged at a certain range of angles relative to the orientation of the external magnetic field, the overall heating performance will still be higher than a susceptor arrangement in which the susceptor elements are randomly oriented.

[0010] Because the overall heating performance of the elongated susceptor elements increases as the deviation from an alignment substantially parallel to the alternating magnetic field used for induction heating decreases, the elongated susceptor elements may preferably be aligned such that the angle between the length dimension of the elongated susceptor element and the direction of movement is within the range of +30° to −30°, preferably +25° to −25°, specifically +10° to −10°. Accordingly, the elongated susceptor elements may be deposited on a major surface of the sheet material in a similar alignment, thereby increasing heating performance. As used herein, the terms “(at least) partially aligned” or “(at least) partially aligned” refer to this type of alignment in the angular range defined above.

[0011] As mentioned above, heating performance is maximized with a substantially parallel alignment. Therefore, it is preferred that the elongated susceptor elements are aligned substantially parallel to the direction of movement. As used herein, the term "substantially parallel" is understood to mean "a deviation of ±5° from a parallel arrangement."

[0012] In general, the elongated susceptor elements may be randomly oriented within the aerosol-forming substrate, but the random arrangement will result in a lower overall heating performance than a collection of elongated susceptor elements aligned at a specific angle range or aligned substantially parallel to the alternating magnetic field, since when considering a collection of susceptor elements, the overall heating performance of a collection of randomly oriented elongated susceptor elements will still be, on statistical average, higher than the heating performance of a collection of non-elongated susceptor elements.

[0013] In the method / apparatus according to the present disclosure, a method / apparatus is provided that allows elongated susceptor elements to be at least partially aligned prior to deposition thereof, such that the at least partially aligned elongated susceptor elements can be ejected at least partially aligned and deposited on a major surface of a sheet material at least partially aligned.

[0014] In the present disclosure, whenever a number or range is given for a plurality of objects, such as a plurality of susceptor elements, this means that the number or range applies to at least 60 percent, particularly at least 70 percent, more particularly at least 80 percent, and particularly at least 90 percent of the plurality of objects, and preferably all of the plurality of objects. For example, the present disclosure states that the elongated susceptor elements are aligned such that the angle between the length dimension of the elongated susceptor element and the direction of movement is within a range of +A degrees to -A degrees, which means that at least 60 percent, particularly at least 70 percent, more particularly at least 80 percent, and particularly at least 90 percent of all elongated susceptor elements are aligned such that the angle between the length dimension of the elongated susceptor element and the direction of movement is within a range of +A degrees to -A degrees.

[0015] In order to discharge the elongated susceptor elements on the main surface of the sheet material, particularly by gravity alone, it may be preferable for the discharge end of the belt conveyor system to be arranged vertically above the sheet material at the deposition location on the main surface.

[0016] As used herein, the term "vertically disposed above" is understood to be in the projection of a plane of the sheet material or in the projection of a plane tangent to the sheet material at the deposition location above the sheet material.

[0017] As used herein, the term "deposition site" refers to the current surface portion of the sheet material on which the elongated susceptor elements are deposited at a given time during the ejection and deposition process on a major surface of the sheet material.

[0018] By providing a discharge end of the belt conveyor system positioned vertically above the sheet material, the elongated susceptor elements can be simply deposited by gravity onto a major surface of the sheet material.

[0019] Alternatively, the discharge end of the belt conveyor system may be disposed vertically below the sheet material at the deposition location on the major surface. Thus, elongated susceptor elements that are not properly deposited on the major surface and / or not adhered to the major surface as desired, such as elongated susceptor elements that are deposited so as to at least partially overlap other elongated susceptor elements, fall off the major surface by gravity. In this arrangement, the elongated susceptor elements are preferably discharged from the upper side of the conveyor belt.

[0020] According to another alternative, the discharge end of the belt conveyor system may preferably be arranged horizontally beside the sheet material at the deposition location on the main surface. As used herein, the term "horizontally arranged beside" is understood to lie in the projection of a plane of the sheet material or in the projection of a plane tangent to the sheet material at the deposition location transverse to the sheet material when the belt conveyor system is in an operative state.

[0021] In order to deposit the elongated susceptor elements onto a large surface area of ​​the sheet material, the belt conveyor system and the discharge end of the sheet material may be moved relative to one another during deposition of the elongated susceptor elements onto a major surface of the sheet material, which is particularly advantageous when the sheet material is provided as a continuous substrate sheet.

[0022] In particular, during the deposition of the elongated susceptor elements onto the main surface of the sheet material, the sheet material may be moved continuously or stepwise relative to (in particular through) the discharge end of the belt conveyor system in a conveying direction that is preferably parallel to a plane defined by the sheet material or parallel to a plane tangent to the sheet material at the deposition location.

[0023] Upon discharge from the conveyor belt, it may be preferred that the projection of the direction of movement of the susceptor elements onto a plane defined by the sheet material or tangent to the sheet material at the deposition location is substantially parallel to the transport direction.

[0024] Movement of the sheet material in the conveying direction to (and particularly beyond) the discharge end of the belt conveyor system may preferably be achieved by a base conveyor belt or by one or more rollers, either continuously or in steps.

[0025] Again, in order to deposit the elongated susceptor elements onto a large surface area of ​​the sheet material, the discharge end of the belt conveyor system may be moved transversely, preferably perpendicularly, to the conveying direction relative to (particularly across) the sheet material while depositing the elongated susceptor elements onto the main surface of the sheet material.

[0026] In particular, in order to deposit the elongated susceptor elements onto a large surface area of ​​the sheet material, while depositing the elongated susceptor elements onto a major surface of the sheet material, the discharge end of the belt conveyor system may be moved relative to (in particular transversely) the sheet material in a plane parallel to the plane defined by the sheet material or parallel to the plane tangent to the sheet material at the deposition location. The movement may in particular be in a direction transverse to the direction of movement of the elongated susceptor elements upon discharge from the conveyor belt and / or in a direction parallel to the projection of the direction of movement upon discharge from the conveyor belt onto the plane defined by the sheet material or onto the plane tangent to the sheet material at the deposition location.

[0027] Alignment of the elongated susceptor elements may preferably be achieved using a magnetic head pulley configured as a permanent magnetic head pulley or as an electromagnetic head pulley.

[0028] The configuration of the magnetic head pulley as a permanent magnetic head pulley or an electromagnetic head pulley may preferably comprise one or more permanent magnets and / or one or more electromagnets, which may be fixedly arranged or may rotate, in particular rotate at the same rotational speed together with the magnetic head pulley.

[0029] When the magnetic head pulley includes multiple permanent magnets, the multiple permanent magnets may be arranged circumferentially around the axis of rotation of the magnetic head pulley within the periphery of the magnetic head pulley.

[0030] Similarly, if the magnetic head pulley includes multiple electromagnets, multiple permanent magnets may be arranged circumferentially around the axis of rotation of the magnetic head pulley within the periphery of the magnetic head pulley.

[0031] At least partial alignment of the elongated susceptor elements may be particularly achieved in a configuration in which the magnetic field outside the magnetic head pulley extends circumferentially around the magnetic head pulley. In particular, when multiple permanent magnets and / or electromagnets are configured by the magnetic head pulley, the magnets may be configured so that the magnetic field extends circumferentially around the magnetic head pulley outside the magnetic head pulley. Preferably, the multiple permanent magnets and / or electromagnets may be configured so that the outermost poles of the magnets relative to the radial direction of the magnetic head pulley alternate between north and south poles, i.e., the magnets are arranged so that the outermost north pole of one magnet is followed by the outermost south pole of another magnet along the circumferential direction of the magnetic head pulley. In particular, adjacent magnets may have alternating outermost north and south poles.

[0032] Alternatively, at least partial alignment of the elongated susceptor elements may be achieved by a magnetic field on the exterior of the magnetic head pulley extending parallel to the rotation axis of the magnetic head pulley. In this case, the elongated susceptor elements are at least partially aligned perpendicular to the direction of movement in a plane tangent to the conveyor belt. Therefore, the elongated susceptor elements may preferably be at least partially aligned such that the angle between the length dimension of the elongated susceptor element and the direction perpendicular to the direction of movement in a plane tangent to the conveyor belt is within the range of +30° to −30°, preferably +25° to −25°, and in particular +10° to −10°. Preferably, the elongated susceptor elements may be aligned substantially parallel to each other and perpendicular to the direction of movement in a plane tangent to the conveyor belt.

[0033] According to another alternative, at least partial alignment of the elongated susceptor elements may be achieved by a magnetic field on the outside of the magnetic head pulley, which disposes the elongated susceptor elements with their length dimension substantially radial to the rotation axis of the magnetic head pulley. In this case, the elongated susceptor elements are at least partially aligned perpendicular to a plane tangent to the conveyor belt. Thus, the elongated susceptor elements may preferably be at least partially aligned such that the angle between the length dimension of the elongated susceptor element and the direction perpendicular to the plane tangent to the conveyor belt is within the range of +30° to −30°, preferably +25° to −25°, and in particular +10° to −10°. Preferably, the elongated susceptor elements may be aligned substantially parallel to each other and perpendicular to the plane tangent to the conveyor belt. This alternative is particularly advantageous when the distance between the conveyor belt and the major surface of the sheet material at the discharge end is smaller than the maximum length extension of the elongated susceptor elements, and the belt conveyor system and the sheet material move relative to each other. Thus, the elongated susceptor elements contacting the major surface of the sheet material are peeled off the conveyor belt in at least partial alignment upon contact with the major surface of the sheet material and deposited on the major surface of the sheet material in at least partial alignment. The at least partially aligned elongated susceptor elements may preferably be peeled off from above the conveyor belt, particularly when the belt conveyor system is disposed vertically below the sheet material, or from below the conveyor belt, particularly when the belt conveyor system is disposed vertically above the sheet material. The sheet material is preferably moved at a linear velocity greater than the linear velocity of the conveyor belt to further enhance alignment with the conveying direction of the sheet material.

[0034] In order to deposit elongated susceptor elements across the width of the sheet material, the belt conveyor system may preferably be configured such that the lateral dimensions of the conveyor belt substantially correspond to the lateral dimensions of the sheet material.

[0035] The aerosol-forming substrate may be made from a substrate slurry cast in the form of a sheet material, and the elongated susceptor elements are preferably deposited on the cast substrate slurry, particularly before drying the cast substrate slurry. Depending on the hardness of the cast substrate slurry, the elongated susceptor elements may be at least partially embedded in the substrate sheet after or during deposition.

[0036] As already mentioned above, the aerosol-forming substrate in the form of a sheet material may be a continuous substrate sheet, thus allowing for the continuous deposition of elongated susceptor elements on the continuous substrate sheet.

[0037] To further improve the production of aerosol-forming substrates, elongated susceptor elements may be deposited on a major surface of the sheet material during or after crimping the continuous substrate sheet, particularly during or after crimping the continuous substrate sheet in its longitudinal direction. The longitudinal direction may be the machine direction of the continuous substrate sheet, preferably parallel to the transport direction. Deposition of the elongated susceptor elements during or after crimping has the advantage that, because the sheet material is corrugated, the formed corrugations are particularly advantageous for accommodating the elongated susceptor elements during deposition, thereby simplifying deposition and improving alignment and distribution of the elongated susceptor elements.

[0038] To improve retention of the elongated susceptor elements and to avoid displacement of the elongated susceptor elements, an adhesive may be applied to a major surface of the sheet material before depositing the elongated susceptor elements thereon. The adhesive may in particular comprise glycerol.

[0039] As mentioned above, the geometry, particularly the relative dimensions, of the elongated susceptor elements have a significant impact on the heating efficiency and, therefore, the substrate extraction efficiency. Therefore, the elongated susceptor elements may be selected so that the ratio of their length dimension to their maximum transverse dimension is greater than 4, particularly 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 term "maximum transverse dimension" refers to the largest dimension of the susceptor wire perpendicular to its major dimension (the length dimension). This ratio may also be referred to as the aspect ratio or form factor.

[0040] As used herein, the ratio of the maximum length dimension of an elongated susceptor element to the maximum transverse dimension of the elongated susceptor element perpendicular to the length dimension is also referred to as the form factor or aspect ratio. Thus, the form factor of an elongated susceptor element is greater than 4, particularly greater than 10, preferably greater than 20, more preferably greater than 25, even more preferably greater than 30, and most preferably greater than 35.

[0041] The ratio of the maximum linear dimension to the maximum transverse dimension (form factor) preferably has an upper as well as a lower limit. Thus, the ratio of the maximum linear dimension of an elongated susceptor element to the maximum transverse dimension perpendicular to the (maximum) linear dimension, i.e., the form factor of the elongated susceptor element, may be in the range of 4 to 500, in particular 10 to 300, preferably 20 to 200, and more preferably 30 to 100.

[0042] In absolute values, the length dimension of the elongated susceptor elements may be in the range of 20 micrometers to 50 millimeters, in particular 100 micrometers to 16 millimeters, preferably 0.5 millimeters to 5 millimeters. Such maximum length dimension is advantageous for deposition according to the present disclosure.

[0043] Depending on the respective absolute values ​​of the maximum length dimensions, the respective absolute values ​​of the maximum transverse dimensions of the elongated susceptor elements are advantageously also selected within the preferred ranges defined above, such that the form factor is above the lower limit defined above. Thus, the maximum transverse dimension of the elongated susceptor elements may be in the range of 5 micrometers to 500 micrometers, in particular 10 micrometers to 150 micrometers, and preferably 80 micrometers to 120 micrometers. In particular, the maximum transverse dimension of the elongated susceptor elements may be 500 micrometers or less, in particular 100 micrometers, preferably 50 micrometers, and more preferably 25 micrometers.

[0044] The heating efficiency also depends on the density of the elongated susceptor elements in the aerosol-forming substrate. The higher the density, the greater the heating efficiency. The (volume) density of the elongated susceptor elements in the aerosol-forming substrate is preferably in the range of 0.001 susceptor elements per cubic millimeter to 30 susceptor elements per cubic millimeter, in particular 0.1 susceptor elements per cubic millimeter to 10 susceptor elements per cubic millimeter. Similarly, the mass density of the elongated susceptor elements in the aerosol-forming substrate may be in the range of 0.002 milligrams of susceptor mass per cubic millimeter to 0.3 milligrams of susceptor mass per cubic millimeter, in particular 0.01 milligrams of susceptor mass per cubic millimeter to 0.1 milligrams of susceptor mass per cubic millimeter.

[0045] In general, the susceptor elements may have any elongated geometric shape. In particular, the elongated susceptor elements may have one of a cylindrical shape or an oblong shape. That is, the elongated susceptor elements may have a rod-like shape or a particle-like shape.

[0046] By way of example, the elongated susceptor elements may be fiber elements, in particular chopped or milled fiber elements. As another example, the elongated susceptor elements may be wire elements, or thread elements, or particle elements, or rod elements. Advantageously, the fiber elements, or wire elements, or thread elements, or particle elements, or filament elements, or rod elements are made of an inductively heatable material, such as metal fiber, wire, or thread, which is readily available at low cost.

[0047] As viewed in a plane perpendicular to the length dimension of the elongated susceptor element, the cross-section of the elongated susceptor element may have a circular, oval, elliptical, triangular, rectangular, square, or polygonal shape. If the cross-section is circular, the aforementioned maximum transverse dimension of the elongated susceptor element corresponds to the diameter of the susceptor element, which is greatest along the length dimension of the elongated susceptor element. If the cross-section is oval or elliptical, the aforementioned maximum transverse dimension of the susceptor element corresponds to the length of the semi-major axis of the oval or elliptical cross-section, which is greatest along the length dimension of the elongated susceptor element. If the cross-section is square or generally rectangular, the aforementioned maximum transverse dimension of the susceptor element corresponds to the length of the edge / major edge of the square / rectangular cross-section.

[0048] Generally, the term "susceptor element" as used herein refers to an element comprising a susceptor material capable of converting electromagnetic energy into heat when subjected to an alternating magnetic field. This may be the result of at least one of hysteresis loss or eddy currents induced in the susceptor material depending on the electrical and magnetic properties of the susceptor material. Hysteresis loss occurs in ferromagnetic or ferrimagnetic susceptor materials due to magnetic domains in the material being switched under the influence of the alternating electromagnetic field. Eddy currents may be induced if the susceptor material is electrically conductive. In the case of an electrically conductive ferromagnetic susceptor or an electrically conductive ferrimagnetic susceptor, heat can be generated due to both eddy currents and hysteresis loss.

[0049] Thus, the elongated susceptor elements may generally be electrically conductive and / or either ferromagnetic or ferrimagnetic. In particular, the susceptor material of the elongated susceptor elements may be non-conductive but ferromagnetic or ferrimagnetic. Alternatively, the susceptor material of the elongated susceptor elements may be electrically conductive but neither ferromagnetic nor ferrimagnetic.

[0050] Preferably, the susceptor material of the elongated susceptor elements may comprise or consist of a metal, such as ferritic iron, or stainless steel, in particular grade 410, grade 420, or grade 430 stainless steel, or a ferrimagnetic ceramic.

[0051] In addition to the susceptor material, the elongated susceptor elements further include a ferromagnetic or ferrimagnetic marker material.

[0052] The susceptor material is optimized for heat loss and therefore heating efficiency, while the temperature marker material is a magnetic (ferromagnetic or ferrimagnetic) material chosen to have a Curie temperature that essentially corresponds to a predetermined temperature point in the heating process.

[0053] The temperature marker material may have a Curie temperature of less than 500° C., preferably less than or equal to 400° C., specifically less than or equal to 390° C. For example, the temperature marker material of the elongated susceptor element may have a Curie temperature in the range of 180° C. to 420° C., specifically 210° C. to 380° C., preferably 250° C. to 380° C. The temperature marker material is primarily a functional material that provides a temperature marker by virtue of its Curie temperature, but may also contribute to the induction heating process of the susceptor arrangement.

[0054] The temperature marker material of the elongated susceptor element may comprise or consist of nickel or a nickel alloy.

[0055] The susceptor element may be formed such that the susceptor material is at least partially, and preferably completely, surrounded or covered by the temperature marker material.

[0056] Furthermore, the elongate susceptor elements may comprise an outer protective coating surrounding the susceptor material and, if present, the temperature marker material, which protective coating preferably makes the elongate susceptor elements resistant to external influences, in particular corrosive influences.

[0057] The provided elongated susceptor elements may have substantially the same characteristics, such as susceptor material, maximum dimension, feature ratio, temperature marker material, outer coating, etc. Alternatively, a mixture of elongated susceptor elements having different characteristics may be provided.

[0058] It is also possible for the susceptor material of the susceptor element itself to have the temperature marker function, i.e. the elongate susceptor element may comprise a single material that acts as both susceptor material and temperature marker material.

[0059] The present disclosure also relates to an apparatus for applying elongated susceptor elements to an aerosol-forming substrate. The apparatus may be particularly suitable for use in a method according to the present disclosure. Accordingly, the above description applies accordingly to the apparatus according to the present disclosure.

[0060] The apparatus may include a belt conveyor system comprising a conveyor belt returning around a magnetic head pulley at a discharge end of the belt conveyor system, the magnetic head pulley configured to generate a magnetic field and attract and align elongated susceptor elements on the conveyor belt as they move around the magnetic head pulley along the magnetic field, such that upon subsequent exit from the magnetic field, the elongated susceptor elements are discharged from the conveyor belt with the discharge end at least partially aligned with respect to the direction of movement.

[0061] The elongated susceptor elements may preferably be provided via a susceptor source, which may in particular be a hopper, which may be connected to a belt conveyor system for providing and feeding the elongated susceptor elements to a conveyor belt upstream of the discharge end.

[0062] Preferably, the aerosol-forming substrate in the form of a sheet material may be provided via a substrate source at or past the discharge end of the belt conveyor system. The sheet material may be provided, in particular vertically, below the discharge end of the belt conveyor system, allowing the at least partially aligned elongated susceptor elements discharged from the discharge end of the belt conveyor system to be deposited on a major surface of the sheet material, preferably under the influence of gravity.

[0063] The substrate source may preferably comprise a conveyor belt or one or more rollers for continuously or stepwise providing the aerosol-forming substrate in the form of a sheet material past the discharge end of the belt conveyor system in a conveying direction which may preferably be parallel to a plane defined by the sheet material or parallel to a plane tangent to the sheet material at a deposition location as it is provided past the discharge end.

[0064] In order to provide optimal deposition of the elongated susceptor elements onto the sheet material, it is preferred that the at least one guide channel be configured and arranged so that the projection of the direction of movement of the elongated susceptor elements upon discharge from the conveyor belt onto a plane defined by the sheet material or, when provided past the discharge end, onto a plane tangent to the sheet material at the deposition location is substantially parallel to the conveying direction.

[0065] The belt conveyor system may preferably be configured so that the discharge end is movable transversely (in particular across) to the sheet material, preferably perpendicularly to the conveying direction.

[0066] To further improve the deposition of the elongated susceptor elements onto a large surface area of ​​the sheet material, the belt conveyor system may be particularly configured such that the discharge end is movable relative to (in particular transverse to) the sheet material in a plane parallel to the plane defined by the sheet material or parallel to the plane that contacts the sheet material at the deposition location when provided at or past the discharge end. Preferably, the movement may be in a direction transverse to the direction of movement of the elongated susceptor elements upon discharge from the conveyor belt and / or parallel to the projection of the direction of movement of the elongated susceptor elements from the conveyor belt onto the plane defined by the sheet material or onto the plane that contacts the sheet material at the deposition location when provided at or past the discharge end.

[0067] The magnetic head pulley may be a permanent magnetic head pulley or an electromagnetic head pulley and may comprise one or more permanent magnets and / or one or more electromagnets.

[0068] In a preferred configuration, the magnetic head pulley may include a plurality of permanent magnets arranged circumferentially around the axis of rotation of the magnetic head pulley within the periphery of the magnetic head pulley, and / or a plurality of electromagnets arranged circumferentially around the axis of rotation of the magnetic head pulley within the periphery of the magnetic head pulley.

[0069] Preferably, the magnetic field outside the magnetic head pulley may extend at least circumferentially around the magnetic head pulley. Alternatively, the magnetic field outside the magnetic head pulley may extend at least partly parallel to the axis of rotation of the magnetic head pulley.

[0070] As used herein, the term "aerosol-generating article" refers to an article comprising at least one aerosol-forming substrate capable of releasing a volatile compound when heated to form an aerosol. The aerosol-generating article may be a consumable product, particularly a consumable product that is discarded after a single use. For example, the article may be an elongated or rod-shaped article. The elongated or rod-shaped article may have a shape similar to that of a conventional cigarette. Specifically, such an article may have a circular, oval, elliptical, square, rectangular, triangular, or polygonal cross section. As another example, the article may be a cartridge containing a liquid aerosol-forming substrate to be heated.

[0071] As used herein, the term "aerosol-forming substrate" refers to a substrate formed from or including an aerosol-forming material capable of releasing a volatile compound upon heating to generate an aerosol. Preferably, the aerosol-forming substrate is intended to be heated, rather than combusted, to release the aerosol-forming volatile compound. Such a substrate may therefore be referred to as a heat-non-combustion aerosol-forming substrate. Similarly, an aerosol-generating article comprising such an aerosol-forming substrate may also be referred to as a heat-non-combustion aerosol-generating article.

[0072] Generally, the aerosol-forming substrate may include at least one aerosol former and at least one sensory material, both of which are volatilizable when heated. The sensory material may include at least one of a tobacco-containing material, a nicotine-containing material, and a flavoring material. Examples of suitable aerosol formers include glycerin and propylene glycol. Examples of flavoring materials may include plant extracts and natural or artificial flavors.

[0073] The aerosol-forming substrate may be a solid aerosol-forming substrate, a gel-like aerosol-forming substrate, or any combination thereof.

[0074] As mentioned above, the aerosol-forming substrate may comprise a tobacco-containing material containing volatile tobacco flavor compounds that are released from the substrate upon heating. Specifically, the aerosol-forming substrate may comprise a reconstituted tobacco material or a tobacco-containing slurry. Thus, the aerosol-generating article may be a tobacco-containing article. Alternatively, or additionally, the aerosol-forming substrate may comprise a non-tobacco material. The aerosol-forming substrate may also comprise other additives and ingredients, such as nicotine or flavoring agents.

[0075] The aerosol-forming substrate may also be a paste-like material, a sachet of porous material containing the aerosol-forming substrate, or loose tobacco mixed with, for example, a gelling or adhesive agent, which may include a common aerosol former such as glycerin, which is compressed or molded into a plug.

[0076] The aerosol-forming substrate is made from a sheet material. For example, the aerosol-forming substrate may be made from a crimped tobacco sheet containing tobacco material, organic fibers, a binder, and an aerosol former. Alternatively, the aerosol-forming substrate may be made from a sheet material containing a nicotine-containing material, organic fibers, a binder, and an aerosol former. As yet another alternative, the aerosol-forming substrate may be made from a sheet material containing tobacco cut filler. In this regard, it has been found that the aerosol-generating article is easy to manufacture, particularly when the susceptor elements are applied to the aerosol-forming substrate when in the form of a sheet material, with respect to the preferred alignment of the elongated susceptor elements with respect to the predefined reference axis of the article. This may be the result of a manufacturing process that includes deposition of the susceptor elements on the outer surface of the sheet material, either during a primary process in which the sheet material is manufactured, or during a secondary process in which the sheet material is machined and combined with other semi-finished products to obtain the final product. As a result, the elongated susceptor elements may ultimately be disposed on the outer surface of the sheet material or may be at least partially embedded in the sheet material near its outer surface, even when the sheet material is subsequently machined, for example, crimped and assembled to form a substrate plug in the final article. [Brief explanation of the drawings]

[0077] [Figure 1] FIG. 1A shows a schematic diagram of a belt conveyor system according to the present invention in a top view. [Figure 1B] FIG. 1B shows a detailed schematic view of the substantially parallel aligned susceptor elements. [Figure 1C] FIG. 1C shows a schematic detail of the partially aligned susceptor elements. [Figure 2] FIG. 2 shows a schematic top view of an apparatus according to one embodiment of the present invention. [Figure 3] FIG. 3 shows a schematic top view of an apparatus according to another embodiment of the invention. [Figure 4] FIG. 4 shows a schematic side view of an apparatus according to an embodiment of the present invention. [Figure 5] FIG. 5 shows a schematic side view of an apparatus according to another embodiment of the invention. [Figure 6] FIG. 6 shows a schematic flow chart of the method according to the invention. [Figure 7] FIG. 7 shows, in schematic detail, a substrate element comprising an elongated susceptor element. [Figure 8] FIG. 8A shows a schematic diagram of a belt conveyor system in a top view according to another embodiment of the present invention. [Figure 8B] FIG. 8B shows a detailed schematic of the substantially parallel aligned susceptor elements. [Figure 8C] FIG. 8C shows a schematic detail of the partially aligned susceptor elements. DETAILED DESCRIPTION OF THE INVENTION

[0078] The present invention is defined in the claims. However, below is provided a non-exhaustive list of non-limiting examples. Any one or more of the features of these examples may be combined with any one or more features described above, for example, with any one or more features of other examples, embodiments, or aspects described herein.

[0079] Example 1: 1. A method for applying elongated susceptor elements to an aerosol-forming substrate for use in an inductively heatable aerosol-generating article, the method comprising the steps of: providing an aerosol-forming substrate in the form of a sheet material; providing elongated susceptor elements; feeding the elongated susceptor elements to a belt conveyor system comprising a conveyor belt; transporting the elongated susceptor elements on the conveyor belt towards a discharge end of the belt conveyor system, the conveyor belt returning around a magnetic head pulley that generates a magnetic field, so that the elongated susceptor elements move around the magnetic head pulley and are attracted and aligned along the magnetic field, and then, upon exiting the magnetic field, the elongated susceptor elements are discharged from the conveyor belt at the discharge end at least partially aligned with respect to the direction of movement; and depositing the elongated susceptor elements discharged from the discharge end of the belt conveyor system onto a major surface of the sheet material, particularly under the influence of gravity.

[0080] Example 2: The method according to example 1, wherein the elongated susceptor elements are at least partially aligned such that the angle between the length dimension of the elongated susceptor element and the direction of movement is in the range of +30 degrees to -30 degrees, preferably +25 degrees to -25 degrees, in particular +10 degrees to -10 degrees, or the elongated susceptor elements are at least partially aligned such that the angle between the length dimension of the elongated susceptor element and a direction perpendicular to the direction of movement in a plane tangent to the conveyor belt is in the range of +30 degrees to -30 degrees, preferably +25 degrees to -25 degrees, in particular +10 degrees to -10 degrees.

[0081] Example 3: 2. The method of example 1, wherein the elongated susceptor elements are aligned substantially parallel to one another along the direction of movement or along a direction perpendicular to the direction of movement in a plane tangent to the conveyor belt.

[0082] Example 4: 4. The method of any one of claims 1 to 3, wherein the discharge end of the belt conveyor system is disposed vertically above the sheet material at a deposition location on the major surface.

[0083] Example 5: The method of any one of Examples 1 to 4, wherein the discharge end of the belt conveyor system and the sheet material move relative to one another while the elongated susceptor elements are deposited on the major surfaces of the sheet material.

[0084] Example 6: The method according to any one of the preceding embodiments, wherein, during the deposition of the elongated susceptor elements onto the main surface of the sheet material, the sheet material moves relative to (in particular through) the discharge end of the belt conveyor system in a conveying direction, the conveying direction being preferably parallel to a plane defined by the sheet material or parallel to a plane tangent to the sheet material at the deposition location.

[0085] Example 7: 7. The method of claim 6, wherein, upon discharge from the conveyor belt, the projection of the direction of movement of the susceptor elements onto a plane defined by the sheet material at the deposition location or onto a plane tangent to the sheet material is substantially parallel to the conveying direction.

[0086] Example 8: 8. The method of any one of claims 6 or 7, wherein the sheet material is moved in the conveying direction to (particularly through) the discharge end of the belt conveyor system by a substrate conveyor belt or by one or more rollers.

[0087] Example 9: 9. The method according to any one of Examples 6 to 8, wherein, during the deposition of the elongated susceptor elements onto the main surface of the sheet material, the discharge end of the belt conveyor system is moved relative to (in particular across) the sheet material in a transverse direction, preferably perpendicular to the conveying direction of the sheet material.

[0088] Example 10: A method according to any one of Examples 1 to 9, wherein, while depositing the elongated susceptor elements on the main surface of the sheet material, the discharge end of the belt conveyor system is moved relative to (in particular transversely) the sheet material in a plane parallel to a plane defined by the sheet material or parallel to a plane tangent to the sheet material at the deposition location, in particular transverse to the direction of movement of the elongated susceptor elements when discharged from the conveyor belt and / or parallel to the projection of the direction of movement of the susceptor elements when discharged from the conveyor belt onto the plane defined by the sheet material or onto the plane tangent to the sheet material at the deposition location.

[0089] Example 11: The method according to any one of Examples 1 to 10, wherein the magnetic head pulley is a permanent magnetic head pulley or an electromagnetic head pulley.

[0090] Example 12: 12. The method according to any one of embodiments 1 to 11, wherein the magnetic head pulley comprises one or more permanent magnets and / or one or more electromagnets.

[0091] Example 13: 13. The method of any one of embodiments 1-12, wherein the magnetic head pulley comprises a plurality of permanent magnets arranged circumferentially within the periphery of the magnetic head pulley and around the axis of rotation of the magnetic head pulley.

[0092] Example 14: 14. The method of any one of embodiments 1-13, wherein the magnetic head pulley comprises a plurality of electromagnets arranged circumferentially within the periphery of the magnetic head pulley and around the axis of rotation of the magnetic head pulley.

[0093] Example 15: 15. The method according to any one of claims 1 to 14, wherein the magnetic field outside the magnetic head pulley extends at least partially circumferentially around the magnetic head pulley, or the magnetic field outside the magnetic head pulley extends at least partially parallel to the rotation axis of the magnetic head pulley.

[0094] Example 16: 16. The method of any one of embodiments 1-15, wherein the lateral dimensions of the conveyor belt substantially correspond to the lateral dimensions of the sheet material.

[0095] Example 17: 17. The method of any one of Examples 1 to 16, wherein the aerosol-forming substrate is made from a substrate slurry cast in the form of a sheet material, and the elongated susceptor elements are deposited on the cast substrate slurry.

[0096] Example 18: The method of example 17, wherein elongated susceptor elements are deposited on a major surface of the sheet material prior to drying the cast substrate slurry.

[0097] Example 19: The method according to any one of examples 1 to 18, wherein the aerosol-forming substrate in the form of a sheet material is a continuous substrate sheet.

[0098] Example 20: The method of Example 19, wherein the elongated susceptor elements are deposited on a major surface of the sheet material during or after crimping the continuous substrate sheet, particularly during or after crimping the continuous substrate sheet in the longitudinal direction, particularly in the machine direction of the continuous substrate sheet.

[0099] Example 21: The method of any one of Examples 1 to 20, wherein an adhesive is applied to a major surface of the sheet material before depositing the susceptor element thereon.

[0100] Example 22: The method of example 21, wherein the adhesive comprises glycerol.

[0101] Example 23: The method according to any one of Examples 1 to 22, wherein the ratio of the length dimension to the maximum transverse dimension of the elongated susceptor elements 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.

[0102] Example 24: A method according to any one of Examples 1 to 23, wherein the ratio of the length dimension to the maximum transverse dimension of the elongate susceptor elements is in the range of 4-500, in particular 10-300, preferably 20-200, more preferably 30-100.

[0103] Example 25: The method according to any one of the preceding embodiments, wherein the length dimension of the elongated susceptor elements is in the range of 20 micrometers to 50 millimeters, in particular 100 micrometers to 16 millimeters, preferably 0.5 millimeters to 5 millimeters.

[0104] Example 26: The method according to any one of Examples 1 to 25, wherein the maximum transverse dimension of the elongated susceptor elements is in the range of 5 micrometers to 500 micrometers, in particular 10 micrometers to 150 micrometers, preferably 80 micrometers to 120 micrometers.

[0105] Example 27: The method according to any one of Examples 1 to 26, wherein the elongate susceptor elements have a maximum transverse dimension of 500 micrometers or less, in particular 100 micrometers, preferably 50 micrometers, more preferably 25 micrometers.

[0106] Example 28: The method of any one of Examples 1-27, wherein the elongated susceptor elements have one of a cylindrical shape or an oblong shape.

[0107] Example 29: 29. The method according to any one of embodiments 1 to 28, wherein the elongated susceptor elements are one of fiber elements, in particular chopped fiber elements or milled fiber elements, or wire elements, or thread elements, or particle elements or rod elements.

[0108] Example 30: 30. The method of any one of Examples 1 to 29, 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 elliptical shape, or an elliptical shape, or a triangular shape, or a rectangular shape, or a quadrilateral shape, or a polygonal shape.

[0109] Example 31: 31. The method of any one of embodiments 1-30, wherein the elongated susceptor elements comprise a susceptor material that is electrically conductive and either one of ferromagnetic or ferrimagnetic.

[0110] Example 32: 32. The method of claim 31, wherein the susceptor material of the elongated susceptor elements comprises or consists of a metal, such as ferritic iron, or stainless steel, particularly grade 410, grade 420, or grade 430 stainless steel, or a ferrimagnetic ceramic.

[0111] Example 33: 33. The method of any one of Examples 31 or 32, wherein the elongated susceptor element further comprises a ferromagnetic or ferrimagnetic temperature marker material in addition to the susceptor material.

[0112] Example 34: 34. The method of example 33, wherein the temperature marker material of the elongated susceptor element comprises or consists of nickel or a nickel alloy.

[0113] Example 35: 10. An apparatus for applying elongated susceptor elements to an aerosol former, particularly for use in the method of any one of Examples 1 to 34, the apparatus comprising: a belt conveyor system comprising a conveyor belt that returns around a magnetic head pulley at a discharge end of the belt conveyor system, the magnetic head pulley configured to generate a magnetic field to move the elongated susceptor elements on the conveyor belt around the magnetic head pulley, attracting and aligning them along the magnetic field, such that upon exiting the magnetic field, the elongated susceptor elements are discharged from the conveyor belt at the discharge end at least partially aligned with respect to the direction of movement.

[0114] Example 36: 36. The apparatus of example 35, further comprising a susceptor source, particularly a hopper, coupled to the belt conveyor system, arranged and configured to provide and feed elongated susceptor elements to the conveyor belt upstream of the discharge end.

[0115] Example 37: An apparatus as described in any one of Examples 35 or 36, further comprising a substrate source for providing an aerosol-forming substrate in the form of a sheet material at or passing through the discharge end of the belt conveyor system, in particular vertically below the discharge end of the belt conveyor system, allowing elongated susceptor elements discharged from the discharge end of the belt conveyor system to be deposited on the main surface of the sheet material, preferably under the influence of gravity.

[0116] Example 38: 38. The apparatus of claim 37, wherein the substrate source comprises a substrate conveyor belt or one or more rollers for providing the aerosol-forming substrate in the form of a sheet material in a conveying direction past the discharge end of the belt conveyor system, the conveying direction preferably being parallel to a plane defined by the sheet material as it is provided past the discharge end of the belt conveyor system or parallel to a plane tangent to the sheet material at the deposition location.

[0117] Example 39: 39. The apparatus of embodiment 38, wherein the belt conveyor system is configured such that the discharge end is movable transversely (in particular across) the sheet material, preferably perpendicularly to the conveying direction.

[0118] Example 40: An apparatus described in any one of Examples 35 to 39, wherein the belt conveyor system is configured so that the discharge end is movable relative to (in particular across) the sheet material in a plane parallel to a plane defined by the sheet material or parallel to a plane tangent to the sheet material when provided at or past the discharge end, in particular in a direction transverse to the direction of movement of the elongated susceptor elements when discharged from the conveyor belt and / or parallel to the projection of the direction of movement of the elongated susceptor elements when discharged from the conveyor belt onto the plane defined by the sheet material or onto a plane tangent to the sheet material at the deposition location.

[0119] Example 41: The apparatus of any one of Examples 35 to 40, wherein the magnetic head pulley is a permanent magnetic head pulley or an electromagnetic head pulley.

[0120] Example 42: 42. The apparatus of any one of Examples 35-41, wherein the magnetic head pulley comprises one or more permanent magnets and / or one or more electromagnets.

[0121] Example 43: 43. The apparatus of any one of Examples 35-42, wherein the magnetic head pulley comprises a plurality of permanent magnets arranged within a periphery of the magnetic head pulley and circumferentially around the axis of rotation of the magnetic head pulley.

[0122] Example 44: 44. The apparatus of any one of Examples 35-43, wherein the magnetic head pulley comprises a plurality of electromagnets arranged circumferentially within the periphery of the magnetic head pulley and around the axis of rotation of the magnetic head pulley.

[0123] Example 45: An apparatus according to any one of Examples 35 to 44, wherein the magnetic field outside the magnetic head pulley extends at least partially circumferentially around the magnetic head pulley, or the magnetic field outside the magnetic head pulley extends at least partially parallel to the axis of rotation of the magnetic head pulley.

[0124] The embodiments will now be further described with reference to the figures.

[0125] All embodiments shown in the figures are schematic and not to scale.

[0126] FIG. 1A illustrates a schematic top view of an example of a belt conveyor system 1. A hopper 2 is disposed upstream of the belt conveyor system 1 to provide elongated susceptor elements 3 onto a conveyor belt 4. The conveyor belt 4 is configured to transport the provided elongated susceptor elements 3 along a moving direction D toward a discharge end 5 of the belt conveyor system 1. The conveyor belt 4 returns around a magnetic head pulley 6. The magnetic head pulley 6 is configured to generate a magnetic field that aligns the elongated susceptor elements 3 moving around the magnetic head pulley 6 along the generated magnetic field. In the example illustrated in FIG. 1A, the elongated susceptor elements 3 are transported along the moving direction D from left to right. Thus, the elongated susceptor elements 3 on the right side of FIG. 1A are aligned substantially parallel to each other compared to the elongated susceptor elements 3 on the left side of FIG. 1A. This is due to the magnetic field generated by the magnetic head pulley 6, which in the example of FIG. 1A extends at least partially circumferentially around the magnetic head pulley 6. When the elongated susceptor elements 3 emerge from the magnetic field, they are discharged from the conveyor belt 4 at a discharge end 5 (below the conveyor belt 4) substantially parallel to one another and aligned in the direction of travel D. From there, they are then deposited onto the main surfaces of the sheet material, in particular under the influence of gravity, substantially parallel to one another and aligned in the direction of travel.

[0127] In the embodiment shown in Figure 1A, the elongated susceptor elements 3 are discharged onto a major surface of an aerosol-forming substrate provided as a sheet material, as shown in detail in Figure 1B, in alignment substantially parallel to one another and to the direction of movement D. In this case, the elongated susceptor elements 3 may also be deposited substantially parallel to the projection of the direction of movement D on a plane defined by the sheet material or on a plane tangent to the sheet material at the deposition location.

[0128] Alternatively, as shown in detail in FIG. 1C , the elongated susceptor elements 3 may be discharged with at least partial alignment, where the angle alpha (α) between the length dimension of the elongated susceptor elements 3 and the direction of movement D is in the range of +30° to −30°, in particular +25° to −25°, and preferably +10° to −10°, and deposited on the main surface of the aerosol-forming substrate, which is provided as a sheet material. Thus, the elongated susceptor elements 3 may be deposited at least partially aligned with the projection of the direction of movement D onto a plane defined by the sheet material or a plane tangent to the sheet material at the deposition location. In this case, the angle alpha (α) is the angle between the length dimension of the elongated susceptor elements 3 and the projection of the direction of movement D onto the plane defined by the sheet material or a plane tangent to the sheet material at the deposition location.

[0129] FIG. 2 shows a schematic top view of an apparatus 9 according to the present invention. The apparatus 9 comprises a belt conveyor system 1 comprising a conveyor belt 4 supplied by a hopper 2 mounted on a beam 13, as shown in FIG. 1 . An aerosol-forming substrate 14 is provided to the apparatus 9 below the belt conveyor system 1 in the form of a sheet material 15 and may be conveyed continuously or stepwise through the belt conveyor system 1 in a conveying direction C. In the embodiment of FIG. 2 , the conveying direction C is parallel to a plane defined by the sheet material 15 (corresponding to the withdrawal plane). The projection of the movement direction D of the elongated susceptor elements onto the plane defined by the sheet material 15 is also parallel to the conveying direction C. The belt conveyor system 1 is movably mounted on the beam 13 and is moved transversely across the sheet material 15 in a transverse direction T perpendicular to the conveying direction C, as shown schematically by a double arrow. The sheet material 15 may be a continuous substrate sheet, as shown schematically in FIG. 2 , or a finite substrate sheet. The sheet material 15 may be conveyed continuously or stepwise through the belt conveyor system 1 in the conveying direction C. The movement of the belt conveyor system 1 along the transverse direction T allows for the deposition of elongated susceptor elements 3 across the entire width of the sheet using a reduced amount of belt conveyor system 1 (which lies in the withdrawal plane and is perpendicular to the conveying direction C). As an example, one belt conveyor system 1 as shown in FIG. 2 may be provided, which moves along the transverse direction T across the entire width of the sheet material 15 and is configured to deposit elongated susceptor elements 3 across the entire width of the sheet material 15. Alternatively, two or more belt conveyor systems 1 mounted on the beam 13 may be provided, each of which is movable along the transverse direction T and configured to deposit elongated susceptor elements 3 onto a respective width portion of the sheet material 15. The elongated susceptor elements 3 are discharged from the belt conveyor system 1 and deposited in at least partial alignment on a major surface of a sheet material 15, as shown in Figures 1A, 1B and 1C.

[0130] FIG. 3 shows a top view of another embodiment of an apparatus 29 according to the invention. The apparatus 29 comprises a belt conveyor system 1 with a conveyor belt 4 mounted on a beam 13. In the embodiment shown in FIG. 3, the conveyor belt 4 has a lateral dimension corresponding to the lateral dimension of the sheet material 15, meaning that the conveyor belt 4 covers the entire width of the sheet material 15. An aerosol-forming substrate 14 is provided to the apparatus 29 below the belt conveyor system 1 in the form of a sheet material 15, which may be conveyed through the belt conveyor system 1 in a conveying direction C. The conveying direction C in the embodiment of FIG. 3 is parallel to a plane defined by the sheet material 15 (corresponding to the withdrawal plane). The projection of the movement direction D onto the plane defined by the sheet material 15 is also parallel to the conveying direction C. The sheet material 15 may be a continuous substrate sheet, as shown schematically in FIG. 3, or a finite substrate sheet. The sheet material 15 may be conveyed through the belt conveyor system 1 in the conveying direction C continuously or in stages. As shown in Figure 3, providing a conveyor belt 4 having lateral dimensions corresponding to the lateral dimensions of the sheet material 15 allows for the deposition of elongated susceptor elements 3 across the entire width of the sheet material 15 without having to provide a moving belt conveyor system 1 as shown in Figure 2. However, such combinations are possible. The elongated susceptor elements 3 are discharged from the belt conveyor system 1 and deposited in at least partial alignment on a major surface of the sheet material 15 as shown in Figures 1A, 1B, and 1C.

[0131] Additionally or alternatively, the beam 13 may be moved relative to the sheet material 15. In the embodiment shown in Figures 2 and 3, the beam 13 may be moved in a beam direction parallel to the conveying direction C, as shown diagrammatically by the double arrow B, even when the sheet material 15 is not being conveyed.

[0132] FIG. 4 shows a schematic, simplified side view of an apparatus according to the present invention. The apparatus of FIG. 4 may be constructed in accordance with the apparatuses 9 and 29 of FIGS. 2 and 3. At least one belt conveyor system 1 is disposed above sheet material 15 on a beam 13. The sheet material 15 is transported in a conveying direction C parallel to a plane defined by the sheet material 15. The sheet material 15 may be transported in the conveying direction C either continuously or stepwise by one or more rollers 17 and / or one or more conveyor belts 18. The conveyor belt 4 of the belt conveyor system 1 returns onto a magnetic head pulley 6 that generates a magnetic field for aligning the elongated susceptor elements 3 transported on the conveyor belt 4 in the moving direction D. The magnetic head pulley 6 may be a permanent magnetic head pulley or an electromagnetic head pulley.

[0133] FIG. 5 shows a more detailed schematic view of a preferred embodiment of the magnetic head pulley 6. The magnetic head pulley 6 includes a plurality of magnets 8 arranged circumferentially within the magnetic head pulley 6 around the axis of rotation of the magnetic head pulley 6. The magnets 8, which may be electromagnets and / or permanent magnets, may rotate with the magnetic head pulley 6 or may be fixed in position. Furthermore, the magnets 8 are positioned and configured such that the magnetic field for at least partially aligning the elongated susceptor elements 3 extends at least partially circumferentially around the magnetic head pulley 6 during at least a portion of the magnetic head pulley 6 where the elongated susceptor elements 3 move around the magnetic head pulley 6 before being ejected upon exiting the magnetic field of the magnetic head pulley 6. For better understanding, FIG. 5 also shows a gap between the elongated susceptor elements 3 and the conveyor belt 4 to separate the elongated susceptor elements 3 from the conveyor belt 4. The elongated susceptor elements 3 are ejected from the conveyor belt at least partially aligned along the direction of movement D. The magnets 8 may be arranged to have alternating outermost north and south magnetic poles N and S along the circumferential direction of the magnetic head pulley 6 to generate an aligning magnetic field that extends at least partially circumferentially around the magnetic head pulley 6. The elongated susceptor elements 3 are thereby at least partially aligned and are subsequently discharged at the discharge end 5 in at least partial alignment.

[0134] 6 shows a flow chart of a method according to the invention. The method of applying elongated susceptor elements 3 to an aerosol-forming substrate 14 for use in an inductively heatable aerosol-generating article according to the invention may be carried out using an apparatus according to the invention, as described above. In a first step 23, the aerosol-forming substrate 14 is provided in the form of a sheet material 15. In a second step 24, elongated susceptor elements 3 are provided. In a subsequent step 25, the elongated susceptor elements 3 provided in step 24 are then fed to a belt conveyor system 1 comprising a conveyor belt 4. In step 26, the elongated susceptor elements 3 are conveyed on the conveyor belt 4 towards the discharge end 5 of the belt conveyor system 1, and the conveyor belt 4 returns around the magnetic head pulley 6 which generates the magnetic field A, attracting and aligning the elongated susceptor elements 3 moving around the magnetic head pulley 6 along the magnetic field A, and thereafter, upon moving away from the magnetic field A, the elongated susceptor elements 3 are discharged from the conveyor belt 4 at the discharge end 5 at least partially aligned with respect to the direction of movement D. In step 27, the elongated susceptor elements 3 are discharged from the discharge end 5 of the belt conveyor system 1 and deposited onto a major surface of the sheet material 15, particularly under the influence of gravity.

[0135] FIG. 7 shows a perspective view of a portion of a substrate element 110 forming part of a rod-shaped aerosol-generating article, including a detailed view (bottom right) of its internal structure, particularly the structure of the aerosol-forming substrate 14 and the elongated susceptor elements 3. As can be seen from both the perspective view and the detailed view, the aerosol-forming substrate 14 is made from a sheet material 15 that assembles into the cylindrical shape of the substrate element 110 when the elongated susceptor elements are deposited thereon. For example, the aerosol-forming substrate 14 may be made from a crimped tobacco sheet containing tobacco material, organic fibers, a binder, and an aerosol. As can be further seen from the detailed view, the elongated susceptor elements 3 are deposited on a major surface of the sheet material 15, which is still visible even after the sheet material 15 has been crimped and assembled. This may be the result of a manufacturing process according to the present invention that includes deposition of the susceptor elements 3 on a major surface of the sheet material 15, either during a primary process in which the sheet material 15 is manufactured, or during a secondary process in which the sheet material 15 is machined. All of the elongated susceptor elements 3 within the base element 110 are aligned along their length dimension (major dimension) substantially parallel to a predetermined reference axis of the aerosol-generating article, where the length axis 101 of the article is selected to coincide with the direction M of the magnetic field lines of an alternating magnetic field that is used to inductively heat the elongated susceptor elements 3 in use, for example, when the aerosol-generating article is engaged with an aerosol-generating device that provides the alternating magnetic field. As previously mentioned, heating efficiency is maximized when all of the elongated susceptor elements 3 are aligned parallel to the direction M of the alternating magnetic field.

[0136] FIG. 8A illustrates a schematic top view of an example of a belt conveyor system 1 according to another embodiment of the present invention. The belt conveyor system substantially corresponds to the belt conveyor system illustrated in FIG. 1A. A hopper 2 is disposed upstream of the belt conveyor system 1 to provide elongated susceptor elements 3 onto a conveyor belt 4. The conveyor belt 4 is configured to transport the provided elongated susceptor elements 3 along a moving direction D toward a discharge end 5 of the belt conveyor system 1. The conveyor belt 4 returns around a magnetic head pulley 6. The magnetic head pulley 6 is configured to generate a magnetic field that aligns the elongated susceptor elements 3 moving around the magnetic head pulley 6 along the generated magnetic field. As with the example illustrated in FIG. 1A, in this example, the elongated susceptor elements 3 are transported along a moving direction from left to right. Contrary to the embodiment shown in Fig. 1A, the elongated susceptor elements 3 on the right side of Fig. 8A are aligned substantially parallel to one another but perpendicular to the direction of movement D in a plane tangent to the conveyor belt 4. This is due to the magnetic field generated outside the magnetic head pulley 6, which in the embodiment of Fig. 8A extends parallel to the axis of rotation of the magnetic head pulley 6. When the elongated susceptor elements 3 emerge from the magnetic field, they are aligned substantially parallel to one another and are discharged from the conveyor belt 4 at a discharge end 5 that is aligned substantially parallel to one another and perpendicular to the direction of movement D in a plane tangent to the conveyor belt 4, and are then aligned substantially parallel to one another on the main surface of the sheet material, in particular under the influence of gravity.

[0137] 8B, similar to FIG. 1B, schematically shows elongated susceptor elements 3 discharged in substantially parallel alignment with one another and perpendicular to the direction of movement D on a major surface of an aerosol-forming substrate provided as a sheet material. In this case, the elongated susceptor elements 3 may also be deposited substantially perpendicular to the projection of the direction of movement D on a plane defined by the sheet material or on a plane tangent to the sheet material at the deposition location.

[0138] Alternatively, as shown in detail in FIG. 8C , the elongated susceptor elements 3 may be discharged at least partially aligned, with an angle alpha (α) between the length dimension of the elongated susceptor elements 3 and a direction perpendicular to the direction of movement D being in the range of +30° to −30°, in particular +25° to −25°, and preferably +10° to −10°, and deposited on a major surface of an aerosol-forming substrate provided as a sheet material. Thus, the elongated susceptor elements 3 may be discharged and deposited at least partially aligned with respect to a projection perpendicular to the direction of movement D onto a plane defined by the sheet material or a plane tangent to the sheet material at the deposition location. In this case, the angle alpha (α) is the angle between the length dimension of the elongated susceptor elements 3 and a projection perpendicular to the direction of movement D onto a plane defined by the sheet material or a plane tangent to the sheet material at the deposition location.

[0139] For purposes of this specification and the appended claims, unless otherwise indicated, all numerical values ​​expressing amounts, quantities, percentages, and the like are to be understood as being modified in all instances by the term "about." Also, all ranges include the maximum and minimum values ​​disclosed, as well as any intermediate ranges contained therein, whether or not specifically recited herein. Thus, in this context, a numerical value A would be understood as A ± 5%. In this context, a numerical value A can be considered to include numerical values ​​that fall within the typical standard error of measurement for the property that A modifies. In some instances, as used in the appended claims, a numerical value A may deviate by the percentages recited above, so long as the amount by which A deviates does not materially affect the basic and novel characteristics of the claimed invention. Also, all ranges include the maximum and minimum values ​​disclosed, as well as any intermediate ranges contained therein, whether or not specifically recited herein.

Claims

1. 1. A method for applying an elongated susceptor element to an aerosol-forming substrate for use in an inductively heatable aerosol-generating article, said method comprising: - providing an aerosol-forming substrate in the form of a sheet material; - providing an elongated susceptor element; - feeding said elongated susceptor elements into a belt conveyor system comprising a conveyor belt; - conveying the elongated susceptor elements on the conveyor belt towards a discharge end of the belt conveyor system, the conveyor belt returning around a magnetic head pulley which generates a magnetic field, the elongated susceptor elements moving around the magnetic head pulley being attracted and aligned along the magnetic field, and then, upon exiting the magnetic field, the elongated susceptor elements being discharged from the conveyor belt at the discharge end at least partially aligned with respect to the direction of movement; - depositing the elongated susceptor elements discharged from the discharge end of the belt conveyor system onto a main surface of the sheet material, in particular under the influence of gravity, A method wherein the aerosol-forming substrate is made from a substrate slurry cast in the form of a sheet material, and the elongated susceptor elements are deposited on the cast substrate slurry.

2. The method of claim 1 , wherein the elongated susceptor elements are aligned substantially parallel to one another in a plane tangent to the conveyor belt, along the direction of movement, or along a direction perpendicular to the direction of movement.

3. 3. The method according to claim 1, wherein, while the elongated susceptor elements are being deposited on the main surface of the sheet material, the sheet material is moved relative to (in particular through) the discharge end of the belt conveyor system in a conveying direction, the conveying direction being preferably parallel to a plane defined by the sheet material or parallel to a plane tangent to the sheet material at the deposition location.

4. The method according to any one of claims 1 to 3, wherein the magnetic head pulley is a permanent magnetic head pulley or an electromagnetic head pulley.

5. The method according to any one of claims 1 to 4, wherein the magnetic head pulley comprises one or more permanent magnets and / or one or more electromagnets.

6. 6. The method of claim 1, wherein the magnetic head pulley includes a plurality of permanent magnets arranged circumferentially within the periphery of the magnetic head pulley and around the axis of rotation of the magnetic head pulley.

7. The method of any one of claims 1 to 6, wherein the magnetic head pulley includes a plurality of electromagnets arranged circumferentially within the periphery of the magnetic head pulley and around the axis of rotation of the magnetic head pulley.

8. 8. The method according to claim 1, wherein the magnetic field outside the magnetic head pulley extends at least partially circumferentially around the magnetic head pulley, or the magnetic field outside the magnetic head pulley extends at least partially parallel to the axis of rotation of the magnetic head pulley.

9. The method of any one of claims 1 to 8, wherein the elongated susceptor elements are deposited on the major surfaces of the sheet material before drying the cast substrate slurry.

10. A method according to any one of claims 1 to 9, wherein the aerosol-forming substrate in the form of a sheet material is a continuous substrate sheet.

11. 11. The method of claim 10, wherein the elongated susceptor elements are deposited on the major surfaces of the sheet material during or after crimping the continuous substrate sheet, particularly during or after crimping the continuous substrate sheet in the longitudinal direction, specifically in the machine direction of the continuous substrate sheet.

12. The method of any one of claims 1 to 11, wherein an adhesive is applied to the major surface of the sheet material before depositing the susceptor element thereon.

13. 13. Apparatus for applying elongated susceptor elements to an aerosol-forming substrate, particularly for use in a method according to any one of claims 1 to 12, the apparatus comprising: an aerosol-forming substrate source; an elongated susceptor element source; and a belt conveyor system comprising a conveyor belt returning around a magnetic head pulley at a discharge end of the belt conveyor system, the magnetic head pulley being configured to generate a magnetic field to cause the elongated susceptor elements on the conveyor belt to move around the magnetic head pulley and to attract and align them along the magnetic field, whereafter, upon exiting the magnetic field, the elongated susceptor elements are discharged from the conveyor belt at the discharge end at least partially aligned with respect to a direction of movement, the aerosol-forming substrate being made from a substrate slurry cast in the form of a sheet material, and the belt conveyor system being configured to deposit the elongated susceptor elements onto the cast substrate slurry.

14. 14. The apparatus of claim 13, wherein the magnetic field outside the magnetic head pulley extends at least partially circumferentially around the magnetic head pulley, or the magnetic field outside the magnetic head pulley extends at least partially parallel to an axis of rotation of the magnetic head pulley.

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