WO2024235631A1

WO2024235631A1 - A method for manufacturing an aerosol generating article

Info

Publication number: WO2024235631A1
Application number: PCT/EP2024/061851
Authority: WO
Inventors: Franck Pourrat
Original assignee: JT International SA
Current assignee: JT International SA
Priority date: 2023-05-12
Filing date: 2024-04-30
Publication date: 2024-11-21
Anticipated expiration: 2025-11-12
Also published as: TW202512944A

Abstract

A method is provided for manufacturing an aerosol generating article (14) for use with an aerosol generating device (12) including at least one resonant transmitter (22), the aerosol generating article (14) comprising an aerosol generating substrate (26) and a susceptor track (30) configured to be inductively heated by the at least one resonant transmitter (22). The method comprises: (i) providing a substantially planar or sheet- type aerosol generating substrate (26); and (ii) printing a susceptor track (30) onto a surface (32) of the aerosol generating substrate (26). The susceptor track (30) covers a lower surface area than a total surface area of the aerosol generating substrate (26).

Description

A METHOD FOR MANUFACTURING AN AEROSOL GENERATING ARTICLE

Technical Field

The present disclosure relates generally to aerosol generating articles, and more particularly to a method for manufacturing an aerosol generating article. The aerosol generating article is for use with an aerosol generating device for heating the aerosol generating article to generate an aerosol for inhalation by a user. The present disclosure is particularly applicable to aerosol generating articles for use with a portable (handheld) aerosol generating device, which may be self-contained and low temperature. Such devices heat, rather than bum, an aerosol generating substrate to generate an aerosol for inhalation.

Technical Background

The popularity and use of reduced-risk or modified-risk devices (also known as vaporisers) has grown rapidly in recent years as an alternative to the use of traditional tobacco products. Various devices and systems are available that heat or warm, rather than bum, an aerosol generating substrate to generate an aerosol for inhalation by a user.

A commonly available reduced-risk or modified-risk device is the heated substrate aerosol generating device, or so-called heat-not-bum device. Devices of this type generate an aerosol or vapour by heating an aerosol generating substrate that typically comprises moist leaf tobacco or other suitable vaporisable material, for example comprised in an aerosol generating article, to a temperature typically in the range 150°C to 350°C, in a heating chamber. Heating the aerosol generating substrate to a temperature within this range, without burning or combusting the aerosol generating substrate, generates a vapour which typically cools and condenses to form an aerosol for inhalation by a user of the device.

Currently available aerosol generating devices can use one of a number of different approaches to provide heat to the aerosol generating substrate. One such approach is to provide an aerosol generating device which employs an induction heating system comprising at least one resonant transmitter, such as an induction coil. An alternating current is supplied to the induction coil when a user activates the device which causes the induction coil to generate an alternating electromagnetic field. The alternating electromagnetic field penetrates an inductively heatable susceptor, thereby heating the susceptor due to the generation of electrical eddy currents within the susceptor and also due to magnetic hysteresis losses in implementations in which the susceptor comprises a ferromagnetic material. The generated heat is transferred from the inductively heatable susceptor, for example by conduction, to the aerosol generating substrate to thereby generate a vapour which may cool and condense to form an inhalable aerosol.

It can be convenient to provide both the aerosol generating substrate and the inductively heatable susceptor together, in the form of an aerosol generating article which can be inserted by a user into an aerosol generating device. As such, there is a need to provide a method which facilitates the manufacture of aerosol generating articles, for example which enables aerosol generating articles to be mass-produced easily and consistently.

Summary of the Disclosure

According to a first aspect of the present disclosure, there is provided a method for manufacturing an aerosol generating article for use with an aerosol generating device including at least one resonant transmitter, the aerosol generating article comprising an aerosol generating substrate and a susceptor track configured to be inductively heated by the at least one resonant transmitter, the method comprising:

(i) providing a substantially planar or sheet-type aerosol generating substrate;

(ii) printing a susceptor track onto a surface of the aerosol generating substrate, wherein the susceptor track covers a lower surface area than a total surface area of the aerosol generating substrate.

Aerosol generating articles produced by the method are for use with an aerosol generating device for heating the aerosol generating substrate, without burning the aerosol generating substrate, to volatise at least one component of the aerosol generating substrate and thereby generate a heated vapour which cools and condenses to form an aerosol for inhalation by a user of the aerosol generating device. The aerosol generating device is a hand-held, portable, device.

In general terms, a vapour is a substance in the gas phase at a temperature lower than its critical temperature, which means that the vapour can be condensed to a liquid by increasing its pressure without reducing the temperature, whereas an aerosol is a suspension of fine solid particles or liquid droplets, in air or another gas. It should, however, be noted that the terms ‘aerosol’ and ‘vapour’ may be used interchangeably in this specification, particularly with regard to the form of the inhalable medium that is generated for inhalation by a user.

The method according to the present disclosure facilitates the manufacture of aerosol generating articles, for example enabling aerosol generating articles to be mass produced consistently and with relative ease by a straightforward process of printing a susceptor track onto a surface of a substantially planar or sheet-type aerosol generating substrate. Printing the susceptor track onto the surface of the aerosol generating substrate also ensures that there is good contact between the susceptor track and the aerosol generating substrate and, thus, optimal heat transfer from the printed susceptor track to the aerosol generating substrate.

A more controlled (progressive) heating of the aerosol generating substrate may also be achieved because the printed susceptor track covers a lower surface area than the total surface area of the aerosol generating substrate, i.e., the susceptor track is printed only on selected areas of the surface of the aerosol generating substrate. As a consequence, some portions of the aerosol generating substrate, e.g., which are positioned further away from the printed susceptor track, may be heated more slowly and progressively (and, thus, depleted more slowly) than other portions of the aerosol generating substrate positioned closer to the printed susceptor track. This improved control of aerosol depletion may in turn allow the generation of vapour or aerosol to be sustained for a longer period of time, and may provide a more consistent aerosol delivery throughout a vaping session. The user experience and user satisfaction are thereby improved. Optional features will now be set out. These are applicable singly or in any combination with any aspect of the present disclosure.

The step of printing the susceptor track onto the surface of the aerosol generating substrate may comprise depositing a layer of slurry containing a susceptor material onto the surface of the aerosol generating substrate or depositing a susceptor material onto the surface of the aerosol generating substrate by a vapour deposition process, for example by physical vapour deposition (PVD) or chemical vapour deposition (CVD).

The method may further comprise:

(iii) forming the aerosol generating substrate and the printed susceptor track into a substantially cylindrical aerosol generating article.

The substantially cylindrical aerosol generating article may be assembled with one or more further components to provide an aerosol generating product, e.g., a substantially cylindrical aerosol generating product. The substantially cylindrical aerosol generating product may be formed substantially in the shape of a stick, for example a heated tobacco stick, and may broadly resemble a cigarette. The substantially cylindrical aerosol generating product may be elongate, and may have a distal end and a proximal end. The circular cross-section may facilitate handling of the product by a user and insertion of the product into a cavity or heating compartment of an aerosol generating device.

The substantially cylindrical aerosol generating product may include a filter segment, for example comprising cellulose acetate fibres or natural cellulose fibres, at the proximal end and/or at the distal end. The or each filter segment may be in coaxial alignment with the substantially cylindrical aerosol generating article. The filter segment at the proximal end may constitute a mouthpiece filter. One or more vapour collection regions, cooling regions, and other structures may also be included in some designs. For example, the aerosol generating product may include at least one intermediate segment, e.g., in the form of a tubular segment, e.g., a paper hollow tube, positioned downstream of the substantially cylindrical aerosol generating article. The intermediate segment may act as a vapour cooling region. The intermediate segment may be provided with a ventilation region (e.g., perforated holes) to allow air to cool down vapour. The vapour cooling region may advantageously allow the heated vapour generated by heating the aerosol generating substrate in the substantially cylindrical aerosol generating article to cool and condense to form an aerosol with suitable characteristics for inhalation by a user, for example through the mouthpiece filter.

Step (ii) may comprise printing a plurality of susceptor tracks onto the surface of the aerosol generating substrate. The susceptor tracks may form portions of susceptor separated by surface portions of substrate not occupied by the susceptor tracks on the surface of the aerosol generating substrate. Printing a plurality of susceptor tracks may allow the heating of the aerosol generating substrate to be optimised, for example by allowing more heat to be generated during use of the aerosol generating article in an aerosol generating device due to inductive heating of the susceptor tracks and/or may allow a more uniform heat distribution depending on the distribution of the susceptor tracks in the aerosol generating article.

The printed susceptor tracks may extend in a first direction parallel to each other and may be spaced apart in a second direction perpendicular to the first direction. This may facilitate printing of the susceptor tracks onto the surface of the aerosol generating substrate and may facilitate the optional step, i.e., step (iii), of forming the aerosol generating substrate and the printed susceptor tracks into a substantially cylindrical aerosol generating article.

In one implementation, step (iii) may comprise: cutting the aerosol generating substrate in the first direction between adjacent pairs of printed susceptor tracks to form a plurality of aerosol generating strips each having a susceptor track printed thereon; assembling a plurality of the aerosol generating strips parallel to each other to form a substantially cylindrical bundle; and wrapping the substantially cylindrical bundle of the assembled aerosol generating strips to form a substantially cylindrical aerosol generating article. The aerosol generating strips are substantially oriented in a longitudinal direction of the aerosol generating article. The aerosol generating strips are typically foldless in the longitudinal direction to ensure that the air flow route is not interrupted and that a uniform air flow through the article can be achieved. The aerosol generating article formed according to this implementation may contain a substantially uniform distribution of the aerosol generating strips each having a susceptor track printed thereon. This in turn ensures that there is a uniform heat distribution throughout the aerosol generating article and may result in better and more consistent aerosol generation and, thus, an improved user experience.

In another implementation, step (iii) may comprise spirally winding the aerosol generating substrate in the second direction to provide a spirally wound substantially cylindrical aerosol generating article comprising a plurality of radially adjacent layers of the aerosol generating substrate. This implementation may offer a convenient way to form the substantially cylindrical aerosol generating article by a simple winding process. The aerosol generating article formed according to this implementation may also provide a uniform heat distribution because of the presence of printed susceptor tracks in radially adjacent layers. Again, this may result in better and more consistent aerosol generation and, thus, an improved user experience.

The susceptor track may be printed onto only one surface of the aerosol generating substrate. An opposite surface of the aerosol generating substrate may be free of susceptor.

The substantially planar or sheet-type aerosol generating substrate may be any type of solid or semi-solid material. Example types of aerosol generating solids include powder, granules, pellets, shreds, strands, particles, gel, strips, loose leaves, cut leaves, cut filler, porous material, foam material or sheets. The substantially planar or sheettype aerosol generating substrate may comprise plant derived material and in particular, may comprise tobacco. It may advantageously comprise reconstituted tobacco, for example including tobacco and any one or more of cellulose fibres, tobacco stalk fibres and inorganic fillers such as CaCCh. The aerosol generating substrate may preferably comprise a reconstituted tobacco sheet. The reconstituted tobacco sheet may be produced by casting, or paper making process, or extrusion and lamination. The reconstituted tobacco sheet may comprise, e.g., tobacco powder, an aerosol former and optionally a binder.

Consequently, the aerosol generating device with which the aerosol generating articles are intended for use may be referred to as a “heated tobacco device”, a “heat-not-bum tobacco device”, a “device for vaporising tobacco products”, and the like, with this being interpreted as a device suitable for achieving these effects. The features disclosed herein are equally applicable to devices which are designed to vaporise any aerosol generating substrate.

The aerosol generating substrate may include an aerosol-former. Examples of aerosolformers include polyhydric alcohols and mixtures thereof such as glycerine or propylene glycol. Typically, the aerosol generating substrate may comprise an aerosolformer content of between approximately 5% and approximately 50% on a dry weight basis of the aerosol generating substrate. In some embodiments, the aerosol generating substrate may comprise an aerosol-former content of between approximately 10% and approximately 20% on a dry weight basis of the aerosol generating substrate, and possibly approximately 15% on a dry weight basis of the aerosol generating substrate.

The susceptor track acts as a resonant receiver and may, thus, comprise an inductively heatable susceptor material. The susceptor material may comprise a ferromagnetic material including, but not limited to, cobalt, iron, nickel, zinc, manganese, and any combinations thereof. In other examples, the susceptor material may comprise other materials, including, for example, other metal materials such as aluminium, stainless steel, carbon steel, as well as ceramic materials such as silicon carbide, carbonaceous materials, and any combinations of any of the materials described above. In further examples, the susceptor material may comprise other conductive materials including metals such as copper, alloys of conductive materials, or other materials with one or more conductive materials embedded therein. With the application of an electromagnetic field in its vicinity during use of the aerosol generating article in an aerosol generating device, the susceptor material may generate heat through the Joule effect due to eddy currents flowing in the susceptor material and, in the case of a ferromagnetic material, by magnetic hysteresis losses. Several factors may contribute to the temperature rise of the susceptor material when penetrated with an alternating electromagnetic field including, but not limited to, the proximity of the susceptor track to the resonant transmitter (e.g., induction coil), the distribution of the magnetic field, the electrical resistivity of the inductively heatable susceptor track, skin effects or depth, hysteresis losses, magnetic susceptibility, and magnetic permeability.

Brief Description of the Drawings

Figure 1 is a diagrammatic view of an aerosol generating system;

Figure 2 is a block diagram illustrating one example of a method for manufacturing an aerosol generating article;

Figure 3a is a diagrammatic top view of an example of an aerosol generating article manufactured by the method according to Figure 2;

Figure 3b is a diagrammatic cross-sectional view of the aerosol generating article of Figure 3a along the line A-A;

Figure 4a is a diagrammatic top view of another example of an aerosol generating article manufactured by the method according to Figure 2;

Figure 4b is a diagrammatic cross-sectional view of the aerosol generating article of Figure 4a along the line B-B;

Figure 5 is a schematic illustration of an embodiment of a method for forming a substantially cylindrical aerosol generating product using the aerosol generating article of Figures 4a and 4b; and

Figure 6 is a schematic illustration of another embodiment of a method for forming a substantially cylindrical aerosol generating product using the aerosol generating article of Figures 4a and 4b.

Detailed Description of Embodiments

Embodiments of the present disclosure will now be described by way of example only and with reference to the accompanying drawings. Figure 1 is a diagrammatic illustration of an example of an aerosol generating system 10 comprising an aerosol generating device 12 and an aerosol generating article 14 according to examples of the present disclosure. The aerosol generating device 12 is a hand-held, portable, device, by which it is meant that a user is able to hold and support the device 12 unaided, in a single hand.

The aerosol generating device 12 includes a power source 16 such as a battery, a controller 18 and a user interface (not shown) for controlling the operation of the aerosol generating device 12 via the controller 18. The aerosol generating device 12 also includes an induction heating assembly 20 comprising a resonant transmitter 22, e.g., an induction coil 24. An alternating current is supplied to the induction coil 24 by the power source 16 and controller 18 when a user activates the device 12, and this causes the induction coil 24 to generate an alternating electromagnetic field.

The controller 18 is configured to detect the initiation of use of the aerosol generating device 12, for example, in response to a user input, such as a button press to activate the aerosol generating device 12, or in response to a detected airflow through the aerosol generating device 12. As will be understood by one of ordinary skill in the art, an airflow through the aerosol generating device 12 is indicative of a user inhalation or ‘puff . The aerosol generating device 12 may, for example, include a puff detector, such as an airflow sensor (not shown) or microphone, to detect an airflow through the aerosol generating device 12.

The aerosol generating article 14 includes an aerosol generating substrate 26 and an inductively heatable susceptor 28. In operation of the aerosol generating device 12, the alternating electromagnetic field generated by the induction coil 24 penetrates the inductively heatable susceptor 28, thereby heating the susceptor 28 due to the generation of electrical eddy currents within the susceptor 28 and also due to magnetic hysteresis losses in examples in which the susceptor 28 comprises a ferromagnetic material. Heat from the susceptor 28 is transferred, for example by conduction, radiation and convection, to the aerosol generating substrate 26 to heat the aerosol generating substrate 26 (without burning or combusting the aerosol generating substrate 26) thereby generating a vapour which cools and condenses to form an aerosol for inhalation by a user of the aerosol generating device 12.

Referring to Figures 2 and 3, there is shown a method for manufacturing an aerosol generating article 14 according to an example of the present disclosure.

The method comprises a first step SI of providing a substantially planar or sheet-type aerosol generating substrate 26. The aerosol generating substrate 26 typically comprises a reconstituted tobacco sheet that includes an aerosol-former. Suitable aerosol formers include, but are not limited to, polyhydric alcohols and mixtures thereof such as glycerine and propylene glycol.

The method comprises a second step S2 of printing a susceptor track 30 onto a surface 32 of the aerosol generating substrate 26. In the illustrated example, the susceptor track 30 is printed only onto one surface 32 of the aerosol generating substrate 26, whereas an opposite surface 33 of the aerosol generating substrate 26 is free of susceptor. The susceptor track 30 constitutes the inductively heatable susceptor 28 described above in the aerosol generating article 14. The susceptor track 30 can be printed onto the surface 32 of the aerosol generating substrate 26 by any suitable deposition method, and thus the printing step S2 may comprise depositing a layer of slurry containing a susceptor material onto the surface 32 of the aerosol generating substrate 26 or depositing a susceptor material onto the surface 32 of the aerosol generating substrate 26 by a vapour deposition process, for example by physical vapour deposition (PVD) or chemical vapour deposition (CVD). These printing methods are not exhaustive and other printing methods are within the scope of the present disclosure. Printing the susceptor track 30 onto the surface 32 of the aerosol generating substrate 26 ensures that there is good contact between the susceptor track 30 and the aerosol generating substrate 26 and, thus, optimal heat transfer from the printed susceptor track 30 to the aerosol generating substrate 26 during use of the aerosol generating article 14 with the aerosol generating device 14. In step S2, the susceptor track 30 is printed onto only part of the surface 32 of the aerosol generating substrate 26. Thus, the susceptor track 30 does not cover the whole surface area of the surface 32 of the aerosol generating substrate 26, and instead covers a lower surface area of the surface 32 than a total surface area of the surface 32 of the aerosol generating substrate 26. This may allow a more controlled (progressive) heating of the aerosol generating substrate 26 to be achieved because some portions of the aerosol generating substrate 26, e.g., that are positioned further away from the printed susceptor track 30, may be heated more slowly and progressively (and, thus, depleted more slowly) than other portions of the aerosol generating substrate 26 that are positioned closer to the printed susceptor track 30. This improved control of aerosol depletion may in turn may allow the generation of vapour or aerosol to be sustained for a longer period of time, and may provide a more consistent aerosol delivery throughout a vaping session, thereby improving the user experience and user satisfaction.

Referring to Figures 4a and 4b which illustrates an example of another aerosol generating article 14, in some examples step S2 comprises printing a plurality of susceptor tracks 30 onto the surface 32 of the aerosol generating substrate 26. The susceptor tracks 30 extend in a first direction X and are spaced apart in a second direction Y that is perpendicular to the first direction. This arrangement is convenient from a manufacturing perspective because it allows the susceptor tracks 30 to be printed simultaneously during step S2. The printed susceptor tracks 30 form portions of susceptor that are separated by surface portions of the aerosol generating substrate 26 that are not occupied by the susceptor tracks 30. The specific arrangement of the susceptor tracks (including the total area of the surface 32 that is covered and distribution across the surface 32) may be selected to optimise the heating of the aerosol generating substrate 26 and/or to provide a uniform heat distribution in the aerosol generating article 14.

In some examples, the aerosol generating article 14 produced by steps SI and S2 as described above may be used in its manufactured form, i.e., as a substantially planar aerosol generating article 14 (e.g., having a flat cuboid shape) that is positioned in use in a correspondingly shaped heating chamber of an aerosol generating device 12. In other examples, the method may comprise an optional further step S3 (see Figure 2) of forming the aerosol generating substrate 26 and printed susceptor track(s) 30 into a substantially cylindrical aerosol generating article 114, 214 as described in further detail below.

Referring to Figure 5, in a first implementation, step S3 comprises a cutting step S3-1, an assembling step S3-2 and a wrapping step S3-3. In more detail, the cutting step S3- 1 comprises cutting the aerosol generating substrate 26, e.g., as illustrated in Figures 4a and 4b, in the first direction X between adjacent pairs of printed susceptor tracks 30. This cutting step S3-1 forms a plurality of aerosol generating strips 34 each having a susceptor track 30 printed thereon. Each printed susceptor track 30 typically covers a lower surface area than the whole surface area of a corresponding aerosol generating strip 34. The assembling step S3-2 comprises assembling a plurality of the aerosol generating strips 34 parallel to each other to form a substantially cylindrical bundle 36. Finally, the wrapping step S3-3 comprises wrapping the substantially cylindrical bundle 36 of the assembled aerosol generating strips 34, e.g., with a paper wrapper 37, to form the substantially cylindrical aerosol generating article 114. The aerosol generating strips 34 are substantially oriented in a longitudinal direction of the aerosol generating article 114 and are typically foldless in the longitudinal direction to ensure that the air flow route is not interrupted and that a uniform air flow through the article 114 can be achieved. The aerosol generating article 114 formed according to this implementation contains a substantially uniform distribution of the aerosol generating strips 34 each having a susceptor track 30 printed thereon, and this in turn ensures that there is a uniform heat distribution throughout the aerosol generating article 114.

Referring to Figure 6, in a second implementation, step S3 comprises a step S3-0 of spirally winding or rolling the aerosol generating substrate 26, e.g., as illustrated in Figures 4a and 4b, in the second direction Y to provide a spirally wound substantially cylindrical aerosol generating article 214 comprising a plurality of radially adjacent layers of the aerosol generating substrate 26. The method further comprises a wrapping step S3-3 which comprises wrapping the spirally wound substantially cylindrical aerosol generating article 214, e.g., with a paper wrapper 37.

In the implementations illustrated in both Figures 5 and 6, step S3 may comprise a final assembly step S3-4 in which the substantially cylindrical aerosol generating article 114, 214 is assembled with other components to form a finished substantially cylindrical aerosol generating product 314. The finished aerosol generating product 314 includes a distal end 38 and a proximal end 40 (or mouth end), and comprises a plug filter 42 at the distal end 38, a mouthpiece filter 44 at the proximal end 40, and an intermediate segment 46 between the substantially cylindrical aerosol generating article 114, 214 and the mouthpiece filter 44. The plug filter 42 and/or the mouthpiece filter may comprise cellulose acetate fibres or natural cellulose fibres. The intermediate segment 46 may comprise poly lactic acid sheets or a hollow tubular segment of paper. The final assembly step S3-4 typically comprises arranging the plug filter 42, the aerosol generating article 114, 214, the intermediate segment 46 and the mouthpiece filter 44 in coaxial alignment and wrapping these components, e.g., with a paper wrapper, to form the finished substantially cylindrical aerosol generating product 314. The finished aerosol generating product is typically in the form of a heated tobacco stick.

Although exemplary embodiments have been described in the preceding paragraphs, it should be understood that various modifications may be made to those embodiments without departing from the scope of the appended claims. Thus, the breadth and scope of the claims should not be limited to the above-described exemplary embodiments.

Any combination of the above-described features in all possible variations thereof is encompassed by the present disclosure unless otherwise indicated herein or otherwise clearly contradicted by context.

Unless the context clearly requires otherwise, throughout the description and the claims, the words “comprise”, “comprising”, and the like, are to be construed in an inclusive as opposed to an exclusive or exhaustive sense; that is to say, in the sense of “including, but not limited to”.

Claims

1. A method for manufacturing an aerosol generating article (14) for use with an aerosol generating device (12) including at least one resonant transmitter (22), the aerosol generating article comprising an aerosol generating substrate (26) and a susceptor track (30) configured to be inductively heated by the at least one resonant transmitter (22), the method comprising:

(i) providing a substantially planar or sheet-type aerosol generating substrate (26);

(ii) printing a susceptor track (30) onto a surface (32) of the aerosol generating substrate (26), wherein the susceptor track (30) covers a lower surface area than a total surface area of the aerosol generating substrate (26).

2. A method according to claim 1, further comprising:

(iii) forming the aerosol generating substrate (26) and the printed susceptor track (30) into a substantially cylindrical aerosol generating article (114, 214).

3. A method according to claim 1 or claim 2, wherein step (ii) comprises printing a plurality of susceptor tracks (30) onto the surface (32) of the aerosol generating substrate (26), wherein the susceptor tracks (30) form portions of susceptor separated by portions of substrate not occupied by the susceptor tracks (30) on the aerosol generating substrate (26).

4. A method according to claim 3, wherein the printed susceptor tracks (30) extend in a first direction parallel to each other and are spaced apart in a second direction perpendicular to the first direction.

5. A method according to claim 4 when dependent on claim 2, wherein step (iii) comprises cutting the aerosol generating substrate (26) in the first direction between adjacent pairs of printed susceptor tracks (30) to form a plurality of aerosol generating strips (34) each having a susceptor track (30) printed thereon, assembling a plurality of the aerosol generating strips (34) parallel to each other to form a substantially cylindrical bundle (36), and wrapping the substantially cylindrical bundle (36) of the assembled aerosol generating strips (34) to form a substantially cylindrical aerosol generating article (114).

6. A method according to claim 4 when dependent on claim 2, wherein step (iii) comprises spirally winding the aerosol generating substrate (26) in the second direction to provide a spirally wound substantially cylindrical aerosol generating article (214) comprising a plurality of radially adjacent layers of the aerosol generating substrate (26).

7. A method according to any preceding claim, wherein the aerosol generating substrate (26) comprises a reconstituted tobacco sheet.

8. A method according to any preceding claim, wherein the susceptor track (30) is printed onto one surface (32) of the aerosol generating substrate (26) and the opposite surface (33) is free of susceptor.