Method and apparatus for aligning elongated susceptor elements within an aerosol-forming substrate

Abstract

In a method for aligning elongated susceptor elements within an aerosol-forming substrate for use in an induction-heatable aerosol-generating article, the aerosol-forming substrate is provided in the form of a sheet material (4) in an alignment device (1) comprising at least one comb (5) having a plurality of teeth (6) arranged in a row. The aerosol-forming substrate includes a plurality of elongated susceptor elements (3). The alignment device (1) and the sheet material (4) are moved relative to each other such that the elongated susceptor elements (3) passing between the teeth (6) of at least one comb (5) are at least partially aligned with respect to a reference axis of the sheet material (4).

Description

Technical Field

[0001] The present disclosure relates to a method of aligning elongate susceptor elements within an aerosol-forming substrate for use in an inductively heatable aerosol-generating article. The present disclosure further relates to an apparatus for aligning elongate susceptor elements within an aerosol-forming substrate, particularly for use in a method according to the present disclosure.

Background Art

[0002] Aerosol generation systems that use inductive heating to generate an inhalable aerosol are generally known from the prior art. Such systems comprise an inductive heating aerosol generator and a separate aerosol-generating article for use with the apparatus. The article can include, among other components, an aerosol-forming substrate having the ability to form an inhalable aerosol when heated, and an inductively heatable susceptor arrangement that is thermally proximate to or physically in direct contact with the substrate to heat the substrate. Inductive heating of the susceptor arrangement is achieved by interaction of the susceptor arrangement with an alternating magnetic field provided by the aerosol generator. In operation, the alternating magnetic field induces at least one of eddy currents or hysteresis losses in the susceptor arrangement, heating the latter to a temperature sufficient to release volatile compounds from the heated substrate, and then cooling to form an aerosol.

[0003] Different configurations of susceptor element arrangements are known, depending on the type of substrate and the shape of the article. For example, an article may comprise a single solid susceptor element, such as a susceptor flake, embedded within a solid or gel-like aerosol-forming substrate within the substrate portion of the article. While solid susceptor elements are inexpensive and readily available, they form a single central heat source that can result in a heterogeneous temperature distribution across the substrate. 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 are heated only indirectly by heat conduction across adjacent substrate layers. In particular, high temperature gradients can overheat the internal regions of the substrate near the susceptor element, while the temperature in the peripheral regions of the substrate 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 containing spherical or quasi-spherical susceptor particles homogeneously obstructed throughout the aerosol-forming substrate have been proposed. While this leads to more homogeneous heating of the substrate, the heating efficiency of this susceptor configuration is limited, which can also affect extraction efficiency. Another alternative is to provide elongated susceptor elements distributed throughout the aerosol-forming substrate or deposited on the main surface of the aerosol-forming substrate. This leads to more uniform heating of the aerosol-forming substrate, but it has been found that proper alignment of the elongated susceptor elements with respect to the applied alternating magnetic field can further increase heating efficiency.

[0004] Therefore, it is desirable to have an induction-heatable aerosol-forming substrate and an apparatus for producing such an aerosol-forming substrate that has the advantages of prior art solutions while mitigating their limitations. In particular, it is desirable to have an aerosol-forming substrate that includes at least partially aligned elongated susceptor elements to provide more efficient heating and utilization of the aerosol-forming substrate. [Overview of the project]

[0005] According to one aspect of the present disclosure, a method is provided for aligning elongated susceptor elements within an aerosol-forming substrate for use in an induction-heatable aerosol-generating article. The method includes the step of providing an aerosol-forming substrate in the form of a sheet material comprising a plurality of elongated susceptor elements to an alignment device comprising at least one comb, the at least one comb comprising a plurality of teeth arranged in a row. The alignment device and the sheet material are moved relative to each other such that the elongated susceptor elements passing between the teeth of the at least one comb are at least partially aligned with respect to a reference axis of the sheet material. [Brief explanation of the drawing]

[0006] [Figure 1A] A schematic top view shows the alignment device according to the present invention. [Figure 1B] A schematic diagram of the aligned, elongated susceptor elements is shown. [Figure 1C] A schematic diagram of the partially aligned, elongated susceptor elements is shown. [Figure 2] A schematic top view shows an alignment device according to another embodiment of the present invention. [Figure 3] A schematic side view shows the alignment device according to the present invention. [Figure 4A] A schematic representation of the comb arrangement according to the present invention is shown. [Figure 4B] A schematic representation of a comb arrangement according to another embodiment of the present invention is shown. [Figure 5] A schematic side view shows an alignment device according to another embodiment of the present invention. [Figure 6] A schematic flowchart of the method according to the present invention is shown below. [Figure 7] The substrate elements, including the elongated susceptor elements, are shown in both schematic and detailed form.

[0007] All examples shown in the diagram are schematic and not to scale. [Modes for carrying out the invention]

[0008] Here, we will further describe the examples with reference to the figures.

[0009] Figure 1A schematically shows an embodiment of the alignment device 1 in a top view. A susceptor supply source 2 is positioned upstream of the alignment device, which includes a comb 5, to supply elongated susceptor elements 3 to an aerosol-forming substrate provided as a sheet material 4. The comb 5 is schematically shown in Figure 4A. The comb 5 has a plurality of teeth 6 arranged in a row, thereby defining a plurality of tooth spacings T between adjacent teeth 6 of the comb 5, and each tooth 6 has a free end 7. The comb 5 is positioned vertically above the sheet material 5, and in the case of the top view in Figure 1A, above the plane of the sheet material 4. For clarity, in the embodiment shown in Figure 1A, the elongated susceptor elements 3 are shown as being deposited on the main surface of the sheet material 4, but according to other possible embodiments, the elongated susceptor elements 3 may be dispersed throughout the aerosol-forming substrate provided as the sheet material 4. The sheet material 4 is transported by the susceptor supply source in the transport direction C, which will be described in more detail later.

[0010] As shown in Figure 4A, the comb 5 is positioned such that the free ends 7 of the teeth 6 of the comb 5 are in contact with the main surface of the sheet material 4. Alternatively, as shown in Figure 4B, if the elongated susceptor elements 3 are dispersed throughout the aerosol-forming substrate provided as the sheet material, the free ends 7 of the teeth 6 of the comb 5 may be positioned below the main surface of the sheet material 4. As the sheet material 4 is conveyed in the conveying direction C and the elongated susceptor elements 3 move with the sheet material, the elongated susceptor elements 3 pass between the teeth 6 of the comb 6, and depending on their original orientation, they may pass without contacting the teeth 6 of the comb 5 or change their orientation by contacting the teeth 6 of the comb 5. The width of the tooth spacing T is selected so that the elongated susceptor elements 3 passing between the teeth 6 of the comb 5 are at least partially aligned with respect to the reference axis R of the sheet material 4. In the embodiment shown in Figure 1A, the elongated susceptor elements 3 are conveyed from left to right along the conveying direction C. Therefore, the elongated susceptor element 3 on the right side of Figure 1A, passing between the teeth 6 of the comb 5, is aligned substantially parallel to each other compared to the elongated susceptor element 3 on the left side of Figure 1A, and is also aligned substantially parallel to the reference axis R of the sheet material 4, as shown in detail in Figure 1B, where the reference axis R is parallel to the transport direction C. In this case, the elongated susceptor element 3 can also be aligned substantially parallel to the projection of the transport direction C onto the plane tangent to the sheet material 4 at the alignment point.

[0011] Alternatively, as shown in detail in Figure 1C, the elongated susceptor element 3 may be aligned with at least partial alignment, and the angle alpha (α) between the length dimension of the elongated susceptor element 3 and the reference axis R parallel to the transport direction C is in the range of +30° to -30°, particularly +25° to -25°, preferably +10° to -10°. As a result, the elongated susceptor element 3 can be aligned with at least partial alignment to the projection of the transport direction C onto the plane in contact with the sheet material at the alignment location.

[0012] Figure 2 schematically shows another embodiment of the alignment device 1 in a top view. The alignment device 1 shown in Figure 2 substantially corresponds to the alignment device 1 shown in Figure 1A, except that the alignment device comprises multiple combs, in the example shown in Figure 2, three combs 5, 5', and 5''. The combs 5, 5', and 5'' are arranged sequentially along the transport direction C, and therefore along the reference axis R of the sheet material 4. The width of the tooth spacing T of comb 5 is greater than the width of the tooth spacing T of comb 5'. Similarly, the width of the tooth spacing T of comb 5' is greater than the width of the tooth spacing T of cam 5''. Thus, the elongated susceptor element 3 is transported along the transport direction C together with the sheet material 4, passing first between the teeth 6 of comb 5, then between the teeth 6 of comb 5', and finally between the teeth of comb 5''. As the width of the tooth spacing T decreases along the transport direction C, the elongated susceptor element 3 aligns more and more with each passing between the teeth 6 of combs 5, 5', and 5',', achieving the desired, at least partial, alignment, which, as shown in Figure 2, is substantially parallel to each other and to the reference axis R. In other words, as shown in Figure 1C, the angle α (alpha) between the length dimension of the elongated susceptor element 3 and the reference axis R decreases with each passing between the teeth 6 of combs 5, 5', and 5''. Combs 5, 5', and 5'' do not necessarily have different tooth spacing T widths. For example, combs 5 and 5' may have the same tooth spacing T width, where T is greater than that of comb 5''. Similarly, combs 5' and 5'' may have the same tooth spacing T width, where T is smaller than that of comb 5.

[0013] Figure 3 shows a schematic and simplified side view of an alignment device 1 according to the present invention and equipped with the above-described substrate supply source. The sheet material 4 is conveyed in a conveying direction C parallel to the plane defined by the sheet material 4. The sheet material 4 may be conveyed in the conveying direction C, either continuously or in stages, by one or more rollers 8 and / or one or more conveyor belts 9. The comb 5 is positioned vertically above the sheet material 4 such that the free ends 7 of the teeth 6 of the comb 5 are in contact with the main surface of the sheet material, as shown in Figure 4A, but the free ends 7 of the teeth 6 of the comb 5 may be positioned below the main surface of the sheet material 4, according to Figure 4B.

[0014] Figure 5 shows a schematic and simplified side view of another embodiment of the alignment device 1 according to the present invention. The substrate supply source corresponds to the substrate supply source shown in Figure 3 and may comprise one or more rollers 8 and / or one or more conveyor belts 9. The alignment device comprises a plurality of combs 5 arranged on a drive mechanism 10 for moving the combs 5 relative to the sheet material 4. The combs 5 are moved relative to the sheet material 4 along a direction of movement D, which may be opposite to the conveying direction C of the sheet material 4, during the alignment of the elongated susceptor elements 3, i.e., when the free ends 7 of the teeth 6 are positioned in the alignment location as shown in Figure 4A or Figure 4B. The plurality of combs 5 may have the same tooth spacing T width or different tooth spacing T widths, as described with respect to the alignment device of Figure 2. For example, the plurality of combs may be a continuous arrangement of combs 5, 5' and 5'', followed by another continuous arrangement having the same arrangement 5, 5' and 5''. As another example, combs 5 may be arranged alternately between two combs 5', or vice versa.

[0015] The alignment device 1 in Figure 5 may be configured to transport the sheet material 4 in stages while continuously operating the drive mechanism 10. The elongated susceptor elements 3 located at the alignment locations are at least partially aligned by passing between the teeth 6 of the comb 5. After alignment, the sheet material 4 is transported in the transport direction until the at least partially aligned elongated susceptor elements 3 are outside the alignment locations, the transport of the sheet material 4 is stopped, and the next portion of the sheet material 4 is subjected to the action of the comb 5, which moves to at least partially align the elongated susceptor elements 3. The process is then repeated. However, preferably, the alignment device 1 is configured such that the sheet material 4, which is preferably a continuous substrate sheet, is transported continuously in the transport direction C beyond the comb 5 where the elongated susceptor elements 3 are at least partially aligned. This embodiment has the advantage that, because the comb 5 is lifted from the sheet material when moving outside the alignment locations, clogging of the comb 5 can be avoided, especially when the alignment device includes multiple combs with different tooth spacing widths T.

[0016] Figure 6 shows a flowchart of the method according to the present invention. The method for aligning elongated susceptor elements in an aerosol-forming substrate can be carried out using the alignment apparatus 1 according to the present invention, as described above. In a first step 20, the aerosol-forming substrate is provided in the form of a sheet material 4, the aerosol-forming substrate including elongated susceptor elements 3 deposited on the main surface of the sheet material 4 and / or dispersed throughout the aerosol-forming substrate provided as the sheet material 4. The sheet material 4, comprising the elongated susceptor elements 3, is provided in step 20 to an alignment apparatus comprising at least one comb 5 having a plurality of teeth 6 arranged in a row. In a second step 21, the sheet material 4, comprising the elongated susceptor elements 3, is moved relative to the alignment apparatus such that the elongated susceptor elements 3 passing between the teeth 6 of at least one comb 5 are at least partially aligned with respect to a reference axis R of the sheet material 4.

[0017] Figure 7 shows a perspective view of a portion of the substrate element 110 that forms part of a rod-shaped aerosol generating article, and a detailed view of its internal structure (lower right), specifically including the structure of the aerosol-forming substrate and the elongated susceptor element 3. As can be seen from both the perspective view and the detailed view, the aerosol-forming substrate is made from a sheet material 4 assembled into the cylindrical shape of the substrate element 110 after the elongated susceptor element 3 has been aligned. For example, the aerosol-forming substrate 4 may be made from a crimped tobacco sheet containing tobacco material, organic fibers, a binder, and aerosol. As can be seen further from the detailed view, at least a portion of the elongated susceptor element 3 is still observable even after the sheet material 4 has been crimped and assembled. This may be the result of a manufacturing process that, according to the present invention, includes the deposition of elongated susceptor elements 3 onto the main surface of a sheet material 4, and at least partial alignment and / or dispersion of the elongated susceptor elements 3 through an aerosol-forming substrate provided as a subsequent sheet material 4, and at least partial alignment of the elongated susceptor elements 3 either during a primary process in which the subsequent sheet material 4 is produced or during a secondary process in which the sheet material 4 is machined. All elongated susceptor elements 3 within the substrate element 110 are aligned along their length dimension (main dimension) substantially parallel to a predetermined reference axis of the aerosol-generating article (corresponding to the reference axis R of the sheet material), where the length axis 101 of the article is selected to coincide with the orientation M of the magnetic field lines of the alternating magnetic field used to inductively heat the elongated susceptor elements 3 when, for example, the aerosol-generating article engages with an aerosol generator that provides an alternating magnetic field. As mentioned above, the heating efficiency is maximized when all the elongated susceptor elements 3 are aligned parallel to the direction M of the alternating magnetic field.

[0018] For the purposes of this specification and the appended claims, unless otherwise indicated, all numbers representing amounts, quantities, percentages, etc., are understood to be modified in all cases by the term “approximately.” Furthermore, all ranges include the disclosed maximum and minimum points and any intermediate ranges within them, which may or may not be specifically listed herein. Thus, in this context, numerical value A is understood as A ± 5% of A. In this context, numerical value A may be considered to include numerical values ​​within the general standard error range for the measurement of the characteristic that numerical value A modifies. In some examples used in the appended claims, numerical value A may deviate by the percentages listed above, as long as the amount of deviation from A does not substantially affect the basic and novel characteristics of the invention described in the claims. Furthermore, all ranges include the disclosed maximum and minimum points and any intermediate ranges within them, which may or may not be specifically listed herein.

[0019] At least one comb tooth is configured to allow passage of an elongate susceptor element where the width of the space between two adjacent teeth, the tooth pitch width, is within a specific partial alignment range with respect to a reference axis. An elongate susceptor element outside the partial alignment range contacts at least one comb tooth and is preferably oriented to be at least partially aligned with respect to the reference axis of the sheet material when passing between at least one comb tooth. For this purpose, at least one comb tooth can have any suitable cross-sectional shape, but preferably has or includes a circular, elliptical, triangular, or polygonal cross-sectional shape. To support at least partial alignment of the elongate susceptor element, the teeth also have or can include pointed cross-sectional shape portions that contact the elongate susceptor element when moving at least one comb relative to the sheet material or vice versa, and facilitate the orientation of the elongate susceptor element to achieve at least partial alignment with respect to the reference axis. By moving the alignment device and the sheet material relative to each other during alignment of the elongate susceptor element, the throughput of the method according to the present disclosure can be increased, and thus the elongate susceptor element can be at least partially aligned over a majority of the sheet material. This is particularly advantageous when the sheet material is provided as a continuous substrate sheet. At least one comb tooth is preferably arranged at equal intervals along the row of teeth, which means that the width of the tooth pitch between adjacent teeth is the same for all teeth of at least one comb.

[0020] As used herein, the term "elongate susceptor element" refers to a susceptor element having a greater extent in one principal dimension than in the two remaining dimensions perpendicular to the principal dimension. Thus, an elongate susceptor element is also represented as a 1D elongate susceptor element (synonymous with a one-dimensionally elongate susceptor element) or a quasi-1D susceptor element (synonymous with a quasi-one-dimensional susceptor element). Specifically, the term "elongate susceptor element" can refer to a susceptor element having a length dimension greater than any cross-sectional dimension perpendicular to the length dimension. More specifically, a 1D elongate susceptor element can be an elongate susceptor element or an oblong susceptor element.

[0021] As used herein, the term "width of the tooth gap" refers to the minimum dimension of the gap between adjacent teeth.

[0022] The present invention is described herein with respect to an elongate susceptor element having a length dimension greater than any transverse dimension that is perpendicular to the length dimension, i.e., a 1D elongate susceptor element having a dimension in one principal direction greater than the dimensions in the remaining two directions that are perpendicular to the principal direction, although this applies equally to susceptor elements having dimensions in two (perpendicular) principal directions greater than the dimension in the remaining direction that is perpendicular to the principal direction. Such susceptor elements are also referred to as 2D elongate susceptor elements. Specifically, the present invention applies equally to susceptor elements having a length dimension and a width dimension that are greater than the thickness dimension, where the length dimension may be greater than or substantially the same as the width dimension. More specifically, the present invention applies equally to susceptor elements having any of an oblate cylindrical shape (e.g., coin shape) or an oblate ellipsoidal shape (e.g., lens shape) or a sheet shape or a plate shape. For these susceptor elements, the same features and advantages described herein for the (1D) elongate susceptor element can be similarly expressed by replacing the term "(1D) elongate susceptor element's maximum length dimension" with the term "two principal direction maximum dimensions of the 2D elongate susceptor element" and replacing "(1D) elongate susceptor element's maximum transverse dimension" with "remaining (non-principal) direction maximum dimension of the 2D elongate susceptor element".

[0023] Compared to a single solid susceptor element, the use of multiple elongated susceptor elements dispersed throughout the aerosol-forming substrate advantageously results in a more homogeneous thermal distribution across the substrate, without significant temperature gradients across different substrate regions. Furthermore, if the susceptor material of the susceptor elements has high thermal conductivity, the homogeneity of the thermal distribution is further enhanced by the fact that a substrate containing multiple dispersed susceptor elements exhibits an equivalent increase in thermal conductivity compared to a substrate without susceptor elements or with only a single solid susceptor element. Moreover, in achieving a homogeneous thermal distribution, the proposed susceptor arrangement is less sensitive to the positioning of the susceptor elements compared to a single solid susceptor element.

[0024] Most importantly, it was found that the geometric shape, specifically the relative dimensions of the susceptor elements, has a significant impact on the heating efficiency of the substrate and, consequently, the extraction efficiency. In this regard, it was found that elongated susceptor elements tend to exhibit a smaller demagnetizing effect compared to relatively equidistant 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 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 can occur. As a result, the magnetization of the susceptor element causes an accumulation of magnetic charge density at both ends of the susceptor element, as seen in the direction of the external magnetic field. Consequently, the susceptor element generates a magnetic field that causes self-interaction with the material. This magnetic field is called a demagnetizing field because it is aligned in the same direction as the external magnetic field but in the opposite direction. The demagnetizing field depends on the geometric shape of the susceptor element, but not on its absolute dimensions. When a susceptor element responds to a change in an external magnetic field, the demagnetizing field is generally assumed to be proportional to the magnetization in each direction, with a geometrically-dependent proportionality constant known as the demagnetizing coefficient. The demagnetizing coefficient depends on the shape of the susceptor element and its relative orientation to the external magnetic field. In this respect, it has been found that an external magnetic field passing through an elongated susceptor element, such as a fiber or thin rod, where the length dimension is significantly larger than any of the transverse dimensions perpendicular to the length, generates a weaker or negligible demagnetizing field compared to a non-elongated (equal-dimensional) susceptor element, such as a spherical or quasi-spherical susceptor element. This is intuitively understandable because, in a properly aligned elongated susceptor element, the magnetic charge densities accumulated at both ends of the susceptor element are more spatially separated from each other. This significantly reduces the intensity of the demagnetizing field, and therefore has less influence on the magnetization field, which is the cause of power loss. As a result, power loss and therefore heating efficiency are greater in elongated susceptor elements compared to non-elongated (equal-dimensional) susceptor elements such as spherical or quasi-spherical susceptor elements.This is especially true when the orientation of the magnetic field is substantially parallel to the length dimension of the elongated susceptor element, in which heating performance is maximized. However, it has been found that the elongated susceptor element does not necessarily need to be perfectly aligned parallel to the direction of the external magnetic field. Even when the susceptor element is aligned within a certain angular range with respect to the orientation of the external magnetic field, the overall heating performance is still higher than that of a susceptor arrangement where the susceptor elements are randomly oriented.

[0025] As described above, the aerosol-forming substrate includes a plurality of elongated susceptor elements. Preferably, the elongated susceptor elements may be deposited on the main surface of the sheet material before passing them between the teeth of at least one comb. In this particular case, at least one comb may be positioned such that the free end of at least one comb tooth, meaning the end of the tooth facing the sheet material, wipes the main surface of the sheet material, thereby at least partially aligning the elongated susceptor elements passing between the teeth.

[0026] To increase the adhesion of elongated susceptor elements to the main surface of the sheet material, an adhesive may be applied to the main surface of the sheet material. The adhesive may be applied before the susceptor elements are deposited thereon. Alternatively, the adhesive may be applied to the main surface of the sheet material after the elongated susceptor elements have been at least partially aligned. Thus, the adhesive can advantageously avoid displacement of the at least partially aligned elongated susceptor elements during subsequent processing of the sheet material. Preferably, the adhesive contains glycerol.

[0027] Displacement of the elongated susceptor elements can also be avoided, or in addition to, by embedding the elongated susceptor elements at least partially in the sheet material, for example, by a pressurizing device and / or rollers, after at least partial alignment of the elongated susceptor elements, instead of applying adhesive.

[0028] Alternatively or additionally, the elongated susceptor elements may be dispersed throughout an aerosol-forming substrate provided as a sheet material. In this case, the aerosol-forming substrate may have a viscosity that allows it to be inserted into the sheet material such that the elongated susceptor elements dispersed therein can move and at least partially align as at least one comb tooth passes between at least one comb tooth. The aerosol-forming substrate is preferably dried, strengthened, and / or cured after the elongated susceptor elements have been at least partially aligned to avoid displacement of the elongated susceptor elements during subsequent processing of the sheet material.

[0029] Since the overall heating performance of elongated susceptor elements increases as the deviation from substantially parallel alignment with the alternating magnetic field used for induction heating decreases, elongated susceptor elements may be aligned such that the angle between the length dimension of the elongated susceptor element and the reference axis is preferably in the range of +30° to -30°, preferably +25° to -25°, specifically +10° to -10°. Thus, an aerosol-forming substrate with increased heating performance can be provided. As used herein, the terms "(at least) partially aligned" or "(at least) partially aligned" refer to this type of alignment within the angular range defined above.

[0030] As described above, heating performance is maximized for substantially parallel alignment. Therefore, it is preferable that the elongated susceptor elements be aligned substantially parallel to the reference axis. As used herein, the term “substantially parallel” is understood to mean “a deviation of ±5° from parallel alignment.”

[0031] Generally, elongated susceptor elements can be randomly arranged within an aerosol-forming substrate; however, random arrangement results in lower overall heating performance compared to an aggregate of elongated susceptor elements aligned within a specific angular range or substantially parallel to the alternating magnetic field. This is because, when considering an aggregate of susceptor elements, the overall heating performance of an aggregate of randomly oriented elongated susceptor elements is still statistically higher than that of an aggregate of non-elongated susceptor elements.

[0032] The present disclosure provides a method / apparatus that enables the easy, at least partially, alignment of elongated susceptor elements deposited on the main surface of a sheet material and / or dispersed throughout an aerosol-forming substrate provided as a sheet material, thus enabling the production of induction-heatable aerosol-generating articles with increased heating performance.

[0033] Whenever a number or range is given for multiple objects, such as multiple susceptor elements, this means that the number or range applies to at least 60 percent, in particular at least 70 percent, more specifically at least 80 percent, in particular at least 90 percent of the multiple objects, and preferably all of the multiple objects. For example, the disclosure states that elongated susceptor elements are aligned such that the angle between the length dimension of the elongated susceptor element and the reference axis is within the range of +A degrees to -A degrees, which means that at least 60 percent, in particular at least 70 percent, more specifically at least 80 percent, in particular 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 reference axis is within the range of +A degrees to -A degrees.

[0034] In particular, during the alignment of elongated susceptor elements, the sheet material may be moved in the conveying direction relative to (especially through) the alignment device, either continuously or in stages. The conveying direction may preferably be parallel to the plane defined by the sheet material, or parallel to the plane in contact with the sheet material at the alignment location.

[0035] As used herein, the term “alignment location” refers to the current (surface) portion of a sheet material through which an elongated susceptor element passes between the teeth of at least one comb of the alignment device.

[0036] The conveying direction may preferably be substantially parallel to the reference axis of the sheet material. Therefore, a sheet material having elongated susceptor elements that are at least partially aligned with respect to both the reference axis and the conveying direction may be provided in particular by providing the sheet material as a continuous substrate sheet, thereby enabling increased alignment performance when using the method according to this disclosure.

[0037] The continuous or stepwise movement of sheet material (especially through it) in the conveying direction relative to the alignment device can be achieved by a base conveyor belt or one or more rollers.

[0038] The alignment device is preferably positioned vertically above the sheet material at the alignment location.

[0039] As used herein, the term “vertically above” is understood to mean the projection of the plane of the sheet material, or the projection of the plane that is in contact with the sheet material at the alignment point above the sheet material.

[0040] The alignment device comprises multiple combs, each comb may have a different tooth spacing width, preferably the lateral distance between adjacent teeth of the comb. The multiple combs may be arranged in an order such that the tooth spacing width decreases along the reference axis of the sheet material.

[0041] By providing an alignment device comprising multiple combs, at least partial alignment is further improved. The alignment device may comprise multiple combs having the same tooth spacing width. Alternatively, at least one of the multiple combs may have a different tooth spacing width than the remaining combs, particularly a narrower tooth spacing width than the remaining combs. In particular, each comb may have a different tooth spacing width and be arranged along the reference axis of the sheet material such that the tooth spacing width decreases. This has proven particularly advantageous when the multiple combs are moved relative to the sheet material, for example using a drive mechanism, along the length extension of the alignment location, particularly along the direction of movement opposite to the conveying direction of the sheet material, so that they are lifted away from the sheet material when they leave the alignment location. Thus, the accumulation of elongated susceptor elements upstream of the combs and comb clogging can be reduced and / or avoided. This is even more preferable when the multiple combs consist of at least one comb having a different tooth spacing width than the remaining combs.

[0042] Therefore, when the alignment device and the sheet material are moved relative to each other, the elongated susceptor element first passes between the widely spaced teeth of the first comb, then between the teeth of the second comb, so that the width of the spacing between the teeth of the second comb may be smaller than the width of the spacing between the teeth of the first comb. Similarly, the elongated susceptor element may pass between the teeth of a third comb, a fourth comb, and so on, until the desired at least partial alignment of the elongated susceptor element with respect to the reference axis is achieved. At least partial alignment of the elongated susceptor element may already be achieved after passing between the teeth of the first comb, and further continuously arranged combs may be used to further enhance the at least partial alignment of the elongated susceptor element. Alternatively, at least the first comb may be used to roughly orient the elongated susceptor element with respect to the reference axis, and one or more of the further continuously arranged combs may be used to at least partially align the elongated susceptor element.

[0043] At least one tooth of the comb may be pre-stressed, particularly in a direction substantially parallel to the reference axis. Pre-stressing of the teeth can be achieved by providing a comb with flexible teeth, or by configuring the teeth of the comb or the comb itself to be mechanically pre-stressed. Thereafter, at least one tooth of the comb is preferably configured such that, when a force exceeding a given threshold is applied, the pre-stressing force is overcome, and therefore the tooth can bend and / or move in response to the applied force (and the pre-stressing force). Thus, the accumulation of elongated susceptor elements upstream of the comb and / or clogging of the comb can be avoided, as it has been shown that the force on the comb teeth increases when elongated susceptor elements accumulate upstream of the comb, particularly by filling the spaces between the comb teeth. Preferably, in arrangements with pre-stressed teeth, the alignment device comprises at least two continuously arranged combs having the same tooth spacing width to ensure that elongated susceptor elements pass at least between the comb teeth, even in the case of accumulation and / or clogging.

[0044] An additional or alternative means to avoid the accumulation of elongated susceptor elements upstream of at least one comb, and / or clogging of the spaces between the teeth of at least one comb, may be to provide a vibration generator for vibrating at least one comb.

[0045] To align elongated susceptor elements across the entire width of the sheet material, the alignment device may be configured such that the lateral dimension of at least one comb substantially corresponds to the lateral dimension of the sheet material.

[0046] The aerosol-forming substrate may preferably be made from a substrate slurry cast in the form of a sheet material, and the elongated susceptor elements may be deposited on the main surface of the sheet material and / or dispersed throughout the sheet material, in particular before the cast substrate slurry is dried. Depending on the hardness of the cast substrate slurry, the elongated susceptor elements may be at least partially embedded within the substrate sheet after or during deposition prior to the alignment process.

[0047] As already mentioned above, the aerosol-forming substrate in the form of a sheet material may be a continuous substrate sheet, thus enabling the continuous alignment of elongated susceptor elements on / within the continuous substrate sheet and increasing the throughput of the method according to this disclosure.

[0048] As described above, the geometric shape of the elongated susceptor element, particularly its relative dimensions, significantly affects the heating efficiency and, consequently, the substrate extraction efficiency. Therefore, the elongated susceptor element may be selected such that the ratio of the length dimension to the maximum cross-sectional 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 cross-sectional dimension" refers to the maximum dimension of the elongated susceptor element perpendicular to the principal dimension (length dimension). This ratio may also be expressed as the aspect ratio or morphological factor.

[0049] As used herein, the ratio of the maximum length dimension of an elongated susceptor element to the maximum cross-sectional dimension of an elongated susceptor element perpendicular to the length dimension is also expressed as a morphological factor or aspect ratio. Therefore, the morphological 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.

[0050] Preferably, the ratio of the maximum length dimension to the maximum cross-sectional dimension (morphological factor) has both a lower and upper limit. Therefore, the ratio of the maximum length dimension of an elongated susceptor element to the maximum cross-sectional dimension perpendicular to the (maximum) length dimension, i.e., the morphological factor of an elongated susceptor element, can be in the range of 4 to 500, particularly 10 to 300, preferably 20 to 200, and more preferably 30 to 100.

[0051] In absolute terms, the length dimension of the elongated susceptor element may be in the range of 20 micrometers to 50 millimeters, particularly 100 micrometers to 16 millimeters, preferably 0.5 millimeters to 5 millimeters. Such maximum length dimensions are advantageous with respect to alignment according to this disclosure.

[0052] Depending on the absolute value of each of the maximum length dimensions, it is preferable that the absolute value of each of the maximum cross-sectional dimensions of the elongated susceptor element be selected to be advantageously within the preferred range defined above, such that the morphological factor exceeds the lower limit defined above. Therefore, the maximum cross-sectional dimension of the elongated susceptor element may be in the range of 5 micrometers to 500 micrometers, particularly 10 micrometers to 150 micrometers, preferably 80 micrometers to 120 micrometers. In particular, the maximum cross-sectional dimension of the elongated susceptor element may be 500 micrometers or less, particularly 100 micrometers, preferably 50 micrometers, and more preferably 25 micrometers.

[0053] To provide efficient alignment of elongated susceptor elements, at least one comb may be configured with tooth spacing widths ranging from 1 to 5 times, particularly 1 to 3 times, and more specifically 1 to 2 times, the maximum transverse dimension of the elongated susceptor elements. In absolute numbers, at least one comb may be configured with tooth spacing widths ranging from 5 micrometers to 1000 micrometers, particularly 5 to 500 micrometers, or 5 to 300 micrometers, more specifically 5 to 150 micrometers, preferably 10 to 120 micrometers, or 80 to 120 micrometers, or 20 to 240 micrometers, or 80 to 240 micrometers. Similarly, at least one comb may be configured with tooth spacing widths of 1000 micrometers, particularly 500 micrometers, more specifically 200 micrometers, preferably 100 micrometers, more preferably 50 micrometers or 25 micrometers or less.

[0054] The heating efficiency also depends on the density of elongated susceptor elements in the aerosol-forming substrate. Higher densities result in greater heating efficiency. The (volume) density of elongated susceptor elements in the aerosol-forming substrate is preferably in the range of 0.001 to 30 susceptor elements per cubic millimeter, specifically 0.1 to 10 susceptor elements per cubic millimeter. Similarly, the mass density of 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, specifically 0.01 milligrams of susceptor mass per cubic millimeter to 0.1 milligrams of susceptor mass per cubic millimeter.

[0055] In general, a susceptor element may have any geometric shape as long as it is elongated. In particular, an elongated susceptor element may have either a cylindrical shape or an elongated ellipse shape. That is, an elongated susceptor element may have a rod-like shape or a particle-like shape.

[0056] As an example, the elongated susceptor element may be a fibrous element, particularly a chopped fiber element or a milled fiber element. In another embodiment, the elongated susceptor element may be a wire element, or a thread element, or a particle element, or a rod element. Advantageously, the fibrous element, or wire element, or thread element, or particle element, or filament element, or rod element may be made from an inductively heatable material such as a metal fiber, or a metal wire, or a metal thread, and are readily available at low cost.

[0057] As seen in a plane perpendicular to the length dimension of an elongated susceptor element, the cross-section of an elongated susceptor element may have the shape of a circle, oval, ellipse, triangle, rectangle, quadrilateral, or polygon. If the cross-section is circular, the aforementioned maximum cross-sectional dimension of the elongated susceptor element corresponds to the diameter of the susceptor element that is maximum along the length dimension of the elongated susceptor element. If the cross-section is elliptical or oval, the aforementioned maximum cross-sectional dimension of the susceptor element corresponds to the length of the semi-major axis of the oval or elliptical cross-section that is maximum along the length dimension of the elongated susceptor element. If the cross-section is quadrilateral or generally rectangular, the aforementioned maximum cross-sectional dimension of the susceptor element corresponds to the length of the edge / major edge of the quadrilateral / rectangular cross-section.

[0058] Generally, as used herein, the term “susceptor element” refers to an element comprising a susceptor material having the ability to convert electromagnetic energy into heat when subjected to an alternating magnetic field. This may result from at least one of hysteresis loss and eddy currents induced within the susceptor material, depending on the electrical properties and magnetism 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 an alternating electromagnetic field. Eddy currents can be induced when the susceptor material is conductive. In the case of a conductive ferromagnetic susceptor or a conductive ferrimagnetic susceptor, heat can be generated due to both eddy currents and hysteresis loss.

[0059] Therefore, elongated susceptor elements can generally be conductive and ferromagnetic or ferrimagnetic, or at least one of the latter. In particular, the susceptor material of an elongated susceptor element may be non-conductive, but may be either ferromagnetic or ferrimagnetic. Alternatively, the susceptor material of an elongated susceptor element may be conductive, but neither ferromagnetic nor ferrimagnetic.

[0060] Preferably, the susceptor material of the elongated susceptor element includes, or may consist of, a metal, such as ferrite iron, or stainless steel, specifically grade 410, grade 420, or grade 430 stainless steel, or ferrimagnetic ceramic.

[0061] In addition to the susceptor material, the elongated susceptor element may further include a ferromagnetic or ferrimagnetic temperature marker material.

[0062] The susceptor material is optimized with respect to heat loss and therefore heating efficiency, while the temperature marker material is a magnetic (ferromagnetic or ferrimagnetic) material selected to have a Curie temperature that essentially corresponds to a given temperature point in the heating process.

[0063] The temperature marker material may have a Curie temperature of less than 500°C, preferably 400°C or less, specifically 390°C or less. For example, the temperature marker material for an 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 its Curie temperature, but it may also contribute to the induction heating process of the susceptor arrangement.

[0064] The temperature marker material of the elongated susceptor element may contain or consist of nickel or a nickel alloy.

[0065] The susceptor element may be formed such that the susceptor material is at least partially, preferably completely, surrounded or covered by the temperature marker material.

[0066] Furthermore, the elongated susceptor element may include an outer protective coating that surrounds the susceptor material and, if present, the temperature marker material. The protective coating preferably makes the elongated susceptor element resistant to external influences, particularly corrosive influences.

[0067] The elongated susceptor elements provided may have substantially identical properties such as susceptor material, maximum dimensions, aspect ratio, temperature marker material, and outer coating. Alternatively, a mixture of elongated susceptor elements having different properties may be provided.

[0068] Furthermore, the susceptor material of the susceptor element itself can also have a temperature marker function. That is, an elongated susceptor element may contain a single material that acts both as a susceptor material and as a temperature marker material.

[0069] This disclosure also relates to an apparatus for aligning elongated susceptor elements in / on an aerosol-forming substrate. The apparatus may be particularly suitable for use in the method according to this disclosure. Accordingly, the above description applies as appropriate to the apparatus according to this disclosure.

[0070] The apparatus may include an alignment device, which comprises at least one comb having a plurality of teeth arranged in a row. An aerosol-forming substrate having elongated susceptor elements is provided to the apparatus as a sheet material. The alignment device and the sheet material are moved relative to each other such that the elongated susceptor elements passing between the teeth of at least one comb are at least partially aligned with respect to a reference axis of the sheet material.

[0071] The elongated susceptor elements can preferably be supplied to and from the aerosol-forming substrate via a susceptor supply source upstream of the alignment device. The susceptor supply source may particularly be a hopper.

[0072] The aerosol-forming substrate in the form of a sheet material may preferably be supplied to or through the alignment device via a substrate supply. The substrate supply source may preferably be configured to supply the sheet material vertically below the magnetic alignment device.

[0073] The substrate supply source may preferably include a conveyor belt or one or more rollers for supplying the aerosol-forming substrate in the form of a sheet material to and / or through the alignment device in a conveying direction, either continuously or in stages. The conveying direction may preferably be parallel to the plane defined by the sheet material, or parallel to the plane in contact with the sheet material at the alignment location.

[0074] The alignment device preferably comprises a plurality of combs, each comb preferably having a different tooth spacing width, and the plurality of combs may be arranged along the reference axis of the sheet material in an order in which the tooth spacing width decreases.

[0075] At least one tooth of the comb may be pre-stressed, preferably in a direction substantially parallel to the reference axis of the sheet material, in order to counteract the accumulation of elongated susceptor elements upstream of at least one comb, particularly due to clogging.

[0076] As an alternative or additional feature to avoid and / or reduce the accumulation of elongated susceptor elements upstream of at least one comb, the device may preferably further include a vibration generator for vibrating at least one comb.

[0077] As used herein, the term “aerosol-generating article” means an article comprising at least one aerosol-forming substrate having the ability to release volatile compounds when heated to form an aerosol. Aerosol-generating articles may be consumables, in particular consumables that are discarded after single use. For example, an article may be an elongated or rod-shaped article. An elongated or rod-shaped article may have a shape similar to that of a conventional cigarette. Specifically, such articles may have a circular, elliptical, oblong, square, rectangular, triangular, or polygonal cross-section.

[0078] As used herein, the term “aerosol-forming substrate” means a substrate formed from or containing an aerosol-forming material having the ability to release volatile compounds upon heating in order to generate aerosols. Preferably, the aerosol-forming substrate is intended to be heated rather than burned in order to release aerosol-forming volatile compounds. Thus, such substrates may be referred to as heat-non-combustible aerosol-forming substrates. Similarly, an aerosol-generating article containing such an aerosol-forming substrate may be referred to as a heat-non-combustible aerosol-generating article.

[0079] Generally, an aerosol-forming substrate may comprise at least one aerosol-forming material and at least one sensory material, both of which are volatile when heated. The sensory material may comprise at least one of a tobacco-containing material, a nicotine-containing material, and a flavoring substance. Examples of suitable aerosol-forming materials are glycerin and propylene glycol. Examples of flavoring substances may include plant extracts and natural or artificial flavors.

[0080] The aerosol-forming substrate may be a solid aerosol-forming substrate, a gel-like aerosol-forming substrate, or any combination thereof.

[0081] As described above, the aerosol-forming substrate may contain tobacco-containing materials that include volatile tobacco-flavored compounds released from the substrate upon heating. Specifically, the aerosol-forming substrate may contain reconstituted tobacco material or tobacco-containing slurry. Therefore, the aerosol-generating article may be a tobacco-containing article. Alternatively or additionally, the aerosol-forming substrate may contain non-tobacco materials. The aerosol-forming substrate may also contain other additives and components (such as nicotine or flavoring agents).

[0082] The aerosol-forming substrate may also be a paste-like material, a sachet of a porous material containing the aerosol-forming substrate, or loose tobacco mixed with, for example, a gelling agent or adhesive, which may contain a common aerosol-forming agent such as glycerin, and which is compressed or molded into a plug.

[0083] Aerosol-forming substrates are made from sheet materials. For example, an aerosol-forming substrate may be made from a crimped tobacco sheet containing tobacco material, organic fibers, a binder, and an aerosol-forming element. Alternatively, an aerosol-forming substrate may be made from a sheet material containing nicotine-containing material, organic fibers, a binder, and an aerosol-forming element. As yet another alternative, an aerosol-forming substrate may be made from a sheet material containing tobacco cut filler. In this regard, aerosol-generating articles may be found to be easy to manufacture, particularly with respect to the preferred alignment of elongated susceptor elements with respect to a predefined reference axis of the article, when applied to and aligned with an aerosol-forming substrate when the elongated susceptor elements are in the form of a sheet material. This may be the result of a manufacturing process that includes the deposition of elongated susceptor elements onto the outer surface of the sheet material and / or the dispersion of elongated susceptor elements within the sheet material, either during the primary process in which the sheet material is manufactured, or when elongated susceptor elements are deposited on the main surface of the sheet material, or during the secondary process in which the sheet material is machined and combined with other semi-finished products to obtain a final product. As a result, the elongated susceptor elements may ultimately be positioned on the outer surface of the sheet material, aligned with each other and at least partially aligned with the reference axis of the sheet material, at least partially embedded in the sheet material near the outer surface of the sheet material, or dispersed throughout the sheet material. This can also be observed when the sheet material is subsequently machined, for example, when it is crimped and assembled to form a substrate plug within the final article. [Examples]

[0084] The present invention is defined in the claims. However, a non-exclusive list of non-limiting embodiments is provided below. One or more features of these embodiments may be combined with one or more features of other embodiments, forms, or aspects described herein.

[0085] Example 1: A method for arranging elongated susceptor elements in an aerosol-forming substrate for use in an induction-heatable aerosol-generating article, the method comprising: providing an aerosol-forming substrate in the form of a sheet material comprising a plurality of elongated susceptor elements to an alignment device comprising at least one comb having a plurality of teeth arranged in a row; and moving the alignment device and the sheet material relative to each other such that the elongated susceptor elements passing between the at least one comb are at least partially aligned with respect to a reference axis of the sheet material. Example 2: The method according to Example 1, wherein elongated susceptor elements are deposited on the main surface of the sheet material. Example 3: The method according to Example 1 or 2, wherein an adhesive is applied to the main surface of the sheet material either before or after depositing the susceptor elements thereon. Example 4: The method according to Example 3, wherein the adhesive contains glycerol. Example 5: The method according to Example 1, wherein elongated susceptor elements are dispersed throughout an aerosol-forming substrate provided as a sheet material. Example 6: The method according to any one of Examples 1 to 5, wherein the elongated susceptor elements are at least partially aligned such that the angle between the length dimension of the elongated susceptor elements and the reference axis is in the range of +30 degrees to -30 degrees, preferably +25 degrees to -25 degrees, and particularly +10 degrees to -10 degrees. Example 7: The method according to any one of Examples 1 to 6, wherein elongated susceptor elements are aligned with respect to each other and substantially parallel to a reference axis. Example 8: The method according to any one of Examples 1 to 7, wherein, during the alignment of elongated susceptor elements, the sheet material is moved in a conveying direction relative to (particularly through) the alignment device, and the conveying direction is preferably parallel to a plane defined by the sheet material or parallel to a plane in contact with the sheet material at the alignment location. Example 9: The method according to Example 8, wherein the conveying direction is substantially parallel to the reference axis. Example 10: The method according to either one of Examples 8 or 9, wherein the sheet material is moved in the transport direction relative to (particularly through) an alignment device by a base conveyor belt or by one or more rollers. Example 11: The method according to any one of Examples 1 to 10, wherein the alignment device is positioned vertically above the sheet material at the alignment location. Example 12: The method according to any one of Examples 1 to 11, wherein the alignment device comprises a plurality of combs, each comb preferably having a different tooth spacing width, and the plurality of combs are arranged along a reference axis of the sheet material in an order in which the tooth spacing width decreases. Example 13: The method according to any one of Examples 1 to 12, wherein at least one tooth of the comb is subjected to a pre-stress, particularly in a direction substantially parallel to the reference axis of the sheet material. Example 14: The method according to any one of Examples 1 to 13, wherein at least one comb can be vibrated by means of a vibration generator. Example 15: The method according to any one of Examples 1 to 14, wherein the transverse dimension of at least one comb substantially corresponds to the transverse dimension of the sheet material. Example 16: The method according to any one of Examples 1 to 15, wherein the aerosol-forming substrate is prepared from a substrate slurry cast in the form of a sheet material. Example 17: The method according to Example 16, wherein elongated susceptor elements are deposited on the main surface of the sheet material or dispersed throughout the sheet material before the cast substrate slurry dries. Example 18: The method according to any one of Examples 1 to 17, wherein the aerosol-forming substrate in the form of a sheet material is a continuous substrate sheet. Example 19: The method according to any one of Examples 1 to 18, wherein the ratio of the length dimension to the maximum cross-sectional dimension of the 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. Example 20: The method according to any one of Examples 1 to 19, wherein the ratio of the length dimension to the maximum cross-sectional dimension of the elongated susceptor element is in the range of 4 to 500, particularly 10 to 300, preferably 20 to 200, and more preferably 30 to 100. Example 21: The method according to any one of Examples 1 to 20, wherein the length dimension of the elongated susceptor element is in the range of 20 micrometers to 50 millimeters, particularly 100 micrometers to 16 millimeters, preferably 0.5 millimeters to 5 millimeters. Example 22: The method according to any one of Examples 1 to 21, wherein the maximum transverse dimension of the elongated susceptor element is in the range of 5 micrometers to 500 micrometers, particularly 10 micrometers to 150 micrometers, preferably 80 micrometers to 120 micrometers. Example 23: The method according to any one of Examples 1 to 22, wherein the maximum transverse dimension of the elongated susceptor element is 500 micrometers or less, particularly 100 micrometers, preferably 50 micrometers, and more preferably 25 micrometers. Example 24: The method according to any one of Examples 1 to 23, wherein the elongated susceptor element has either a cylindrical or elongated elliptical shape. Example 25: The method according to any one of Examples 1 to 24, wherein the elongated susceptor element is one of the following: a fibrous element, particularly a chopped fiber element or a milled fiber element, or a wire element, or a thread element, or a particle element, or a rod element. Example 26: The method according to any one of Examples 1 to 25, wherein the cross-section of the elongated susceptor element in a plane perpendicular to the length dimension of the susceptor element is circular, oval, elliptical, triangular, rectangular, quadrilateral, or polygonal in shape. Example 27: The method according to any one of Examples 1 to 26, comprising a susceptor material in which an elongated susceptor element is conductive and either ferromagnetic or ferrimagnetic. Example 28: The method according to Example 27, wherein the susceptor material of the elongated susceptor element includes, or consists of, a metal, such as ferrite iron, or stainless steel, specifically grade 410, grade 420, or grade 430 stainless steel, or ferrimagnetic ceramics. Example 29: The method according to either Example 27 or 28, wherein the elongated susceptor element further comprises a ferromagnetic or ferrimagnetic temperature marker material in addition to the susceptor material. Example 30: The method according to Example 29, wherein the temperature marker material of the elongated susceptor element contains or is made of nickel or a nickel alloy. Example 31: The method according to any one of Examples 1 to 30, wherein at least one comb is composed of teeth with a spacing width in the range of 1 to 5 times, particularly 1 to 3 times, and more specifically 1 to 2 times, the maximum transverse dimension of the elongated susceptor element. Example 32: The method according to any one of Examples 1 to 31, wherein at least one comb has tooth spacing widths in the range of 5 micrometers to 1000 micrometers, particularly 5 micrometers to 500 micrometers, or 5 micrometers to 300 micrometers, more specifically 5 micrometers to 150 micrometers, preferably 10 micrometers to 120 micrometers, or 80 micrometers to 120 micrometers, or 20 micrometers to 240 micrometers, or 80 micrometers to 240 micrometers. Example 33: The method according to any one of Examples 1 to 32, wherein at least one comb is configured with a tooth spacing width of 1,000 micrometers, particularly 500 micrometers, more specifically 200 micrometers, preferably 100 micrometers, more preferably 50 micrometers or 25 micrometers or less. Example 34: Apparatus for arranging elongated susceptor elements in / on an aerosol-forming substrate, particularly for use in the method of any one of Examples 1 to 33, wherein the apparatus comprises an arrangement device having at least one comb having a plurality of teeth arranged in a row, the aerosol-forming substrate being provided to the apparatus as a sheet material, and the arrangement device and the sheet material being moved relative to each other such that elongated susceptor elements passing between the teeth of at least one comb are at least partially aligned with respect to a reference axis of the sheet material. Example 35: The apparatus according to Example 34, further comprising a susceptor supply source configured to provide and supply elongated susceptor elements to an aerosol-forming substrate upstream of the alignment device. Example 36: The apparatus according to either one of Example 34 or 35, further comprising a substrate supply source for providing an aerosol-forming substrate in the form of a sheet material to or through the alignment device, particularly vertically below the alignment device. Example 37: The apparatus according to Example 36, wherein the substrate supply source includes one or more rollers for supplying an aerosol-forming substrate in the form of a sheet material to or through the alignment device in the conveying direction. Example 38: The apparatus according to any one of Examples 34 to 37, wherein the alignment device comprises a plurality of combs, each comb preferably having a different tooth spacing width, and the plurality of combs are arranged along a reference axis of the sheet material in an order in which the tooth spacing width decreases. Example 39: The apparatus according to any one of Examples 34 to 38, wherein at least one tooth of the comb is subjected to pre-stress in a direction substantially parallel to the reference axis of the sheet material. Example 39: The apparatus according to any one of Examples 34 to 39, further comprising a vibration generator for vibrating at least one comb.

Claims

1. A method for aligning elongated susceptor elements in an aerosol-forming substrate for use in an induction-heatable aerosol-generating article, wherein the method is: - A step of providing an aerosol-forming substrate in the form of a sheet material, which includes a plurality of elongated susceptor elements, to an alignment device equipped with at least one comb having a plurality of teeth arranged in a row, and A method comprising the step of moving the alignment device and the sheet material relative to each other such that the elongated susceptor element passing between at least one tooth is at least partially aligned with respect to a reference axis of the sheet material.

2. The method according to claim 1, wherein the elongated susceptor elements are deposited on the main surface of the sheet material.

3. The method according to claim 1, wherein the elongated susceptor elements are dispersed throughout the aerosol-forming substrate provided as a sheet material.

4. The method according to any one of claims 1 to 3, wherein the elongated susceptor elements are at least partially aligned such that the angle between the length dimension of the elongated susceptor elements and the reference axis is in the range of +30 degrees to -30 degrees, preferably +25 degrees to -25 degrees, and particularly +10 degrees to -10 degrees.

5. The method according to any one of claims 1 to 4, wherein the elongated susceptor elements are aligned with respect to each other and substantially parallel to the reference axis.

6. The method according to any one of claims 1 to 5, wherein, during the alignment of the elongated susceptor elements, the sheet material is moved in a transport direction relative to (particularly through) the alignment device, and the transport direction is preferably parallel to a plane defined by the sheet material or parallel to a plane in contact with the sheet material at the alignment location.

7. The method according to claim 6, wherein the transport direction is substantially parallel to the reference axis.

8. The method according to any one of claims 6 or 7, wherein the sheet material is moved in the conveying direction relative to (particularly through) the alignment device by a base conveyor belt or by one or more rollers.

9. The method according to any one of claims 1 to 8, wherein the alignment device comprises a plurality of combs, each comb preferably having a different tooth spacing width, and the plurality of combs are arranged along the reference axis of the sheet material in an order in which the tooth spacing width decreases.

10. The method according to any one of claims 1 to 9, wherein pre-stress is applied to at least one tooth of the comb, particularly in a direction substantially parallel to the reference axis of the sheet material.

11. The method according to any one of claims 1 to 10, wherein the aerosol-forming substrate is made from a substrate slurry cast in the form of the sheet material.

12. The method according to claim 11, wherein the elongated susceptor elements are deposited on the main surface of the sheet material or dispersed throughout the sheet material before the cast substrate slurry is dried.

13. The method according to any one of claims 1 to 12, wherein the aerosol-forming substrate in the form of the sheet material is a continuous substrate sheet.

14. The method according to any one of claims 1 to 13, wherein the ratio of the length dimension to the maximum cross-sectional dimension of the 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.

15. In particular, an apparatus for aligning elongated susceptor elements in / on an aerosol-forming substrate for use in the method according to any one of claims 1 to 14, wherein the apparatus is An alignment device comprising at least one comb having multiple teeth arranged in a row, A substrate supply source for supplying an aerosol-forming substrate in the form of a sheet material to or through an alignment device, wherein the aerosol-forming substrate comprises an elongated susceptor element, The apparatus is configured to move the alignment device and the sheet material relative to each other such that the elongated susceptor element passing between at least one tooth is at least partially aligned with respect to a reference axis of the sheet material.

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