AEROSOU GENERATING ARTICEE

Technical Field

The present disclosure relates generally to aerosol generating articles, and more particularly to an aerosol generating article for use with an aerosol generating device for heating the aerosol generating article to generate an aerosol for inhalation by a user. Embodiments of the present disclosure relate in particular to a method for manufacturing an aerosol generating article and/or to an apparatus for manufacturing an aerosol generating article.

Technical Background

Devices which heat, rather than bum, an aerosol generating material to produce an aerosol for inhalation have become popular with consumers in recent years.

Such devices can use one of a number of different approaches to provide heat to the aerosol generating material. One such approach is to provide an aerosol generating device which employs an induction heating system and into which an aerosol generating article, comprising aerosol generating material, can be removably inserted by a user. In such a device, an induction coil is provided with the device and an inductively heatable susceptor is provided typically with the aerosol generating article. Electrical energy is supplied to the induction coil when a user activates the device which in turn generates an alternating electromagnetic field. The susceptor couples with the electromagnetic field and generates heat which is transferred, for example by conduction, to the aerosol generating material and a vapour or aerosol is generated as the aerosol generating material is heated.

It can be convenient to provide the aerosol generating material 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 and apparatus which facilitates the manufacture of aerosol generating articles. Summary of the Disclosure

According to a first aspect of the present disclosure, there is provided a method for manufacturing an aerosol generating article, the method comprising:

(i) providing a plant-based aerosol generating material;

(ii) providing an inductively heatable susceptor element;

(iii) providing a cup comprising a bottom wall, a side wall and a flange at an open end;

(iv) depositing a layer of plant-based aerosol generating material in the cup;

(v) placing the inductively heatable susceptor element on the deposited layer of plant-based aerosol generating material;

(vi) optionally repeating step (iv) only or steps (iv) and (v);

(vii) providing a closure and affixing the closure on the flange.

The present disclosure provides a convenient method for manufacturing aerosol generating articles comprising a plant-based aerosol generating material and an inductively heatable susceptor element, and in particular which facilitates the mass production of aerosol generating articles.

The aerosol generating article is for use with an aerosol generating device for heating the plant-based aerosol generating material, without burning the aerosol generating material, to volatise at least one component of the plant-based aerosol generating material and thereby generate a vapour which cools and condenses to form an aerosol for inhalation by a user of the aerosol generating 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 use of an inductively heatable susceptor element provides a convenient, effective and energy efficient way to heat the plant-based aerosol generating material. When the aerosol generating article is positioned in an aerosol generating device and exposed to an alternating electromagnetic field, heat is generated in the inductively heatable susceptor element due to eddy currents and magnetic hysteresis losses resulting in a conversion of energy from electromagnetic to heat. The heat generated in the inductively heatable susceptor element is transferred to the plant-based aerosol generating material whereupon it is heated to generate a vapour which cools and condenses to form an aerosol with the desired characteristics.

The inductively heatable susceptor element may comprise one or more, but not limited, of aluminium, iron, nickel, stainless steel and alloys thereof, e.g. Nickel Chromium or Nickel Copper.

The inductively heatable susceptor element may comprise a substantially planar inductively heatable susceptor element and may comprise a substantially ring-shaped inductively heatable susceptor element.

The cup may be a paper cup and may be a moulded paper cup. A paper cup is cheap, easy to manufacture, compostable and is safe for use even at high temperatures. The paper cup may have a self-supporting moulded form. This enables the cup to retain its shape and facilitates handling of the cup during manufacture of the aerosol generating article.

The cup and/or closure may further contain tobacco and/or flavour. The tobacco and/or flavour may improve or mask the taste of paper and give it a more pleasant taste. The flavour may be tobacco, fruit, plant, nut, flower and so on. The tobacco and/or flavour may be contained as an ingredient of the paper. The tobacco may be embedded in the paper or applied thereon such as by coating or layering. The tobacco may be in the form particles, flakes, leaf fragments, strip(s), layer(s) and combinations thereof. The cup may be substantially cylindrical. The side wall may be substantially cylindrical. The bottom wall may be substantially circular. The closure may be substantially circular. A cup with a cylindrical form, having a substantially circular cross-section, may facilitate handling of the cup during manufacture of the aerosol generating article. The cylindrical form of the resulting aerosol generating article with its substantially circular cross-section may facilitate packaging of multiple aerosol generating articles and/or may facilitate insertion of the aerosol generating article into a correspondingly shaped heating compartment of an aerosol generating device. The cylindrical form enables the insertion of several identical susceptor elements while maintaining a homogeneous heating of the aerosol generating material. Therefore, the manufacturing complexity is reduced while the effectiveness of the system ensured.

The flange may extend outwardly away from the side wall. Thus, the flange does not extend across the open end of the cup, thereby allowing the plant-based aerosol generating material and the inductively heatable susceptor element(s) to be easily positioned in the cup during steps (iv), (v) and optionally during step (vi). In embodiments in which the side wall is substantially cylindrical, the flange may comprise a substantially circular lip.

The bottom wall of the cup may be porous or perforated. For example, the bottom wall may comprise a material which is porous to allow air to flow through the bottom wall. Alternatively or in addition, the bottom wall may include one or more openings or perforations. In the latter case, the bottom wall may comprise a material which is itself resistant to air such that the openings or perforations are needed to allow air to flow through the bottom wall. The provision of a porous or perforated bottom wall advantageously promotes air flow through the aerosol generating article thereby optimising aerosol generation and transfer to the user, for example via a mouthpiece of an aerosol generating device.

The closure may be porous or perforated. For example, the closure may comprise a material having a porous structure to allow air to flow through the closure. Alternatively or in addition, the closure may include one or more openings or perforations. In the latter case, the closure may comprise a material which is itself resistant to air such that the openings or perforations are needed to allow air to flow through the closure. In addition to retaining the plant-based aerosol generating material in the cup, the porous or perforated closure advantageously promotes air flow through the aerosol generating article thereby optimising aerosol generation and transfer to the user, for example via a mouthpiece of an aerosol generating device.

By“air-resistant” is meant a material that is not necessarily barrier to oxygen during storage but a material that at least does not allow the flow of air and vapour during use.

Step (iv) may comprise dosing and depositing the plant-based aerosol generating material as granules, pellets, shreds, strands, particles, gel, strips, loose leaves, cut leaves, cut filler, porous material, foam material or sheets or combinations thereof. The step of dosing the plant-based aerosol generating material may comprise weighing the plant-based aerosol generating material. Accurate dosing of the aerosol generating material is thereby assured, in turn ensuring that an aerosol with the desired characteristics is generated during use of the aerosol generating article with an aerosol generating device.

The method may further comprise flattening the deposited layer of plant-based aerosol generating material. The step of flattening the deposited layer of aerosol generating material may be performed after step (iv) and may be performed prior to step (v). Flattening of the deposited layer of aerosol generating material may facilitate placement of the inductively heatable susceptor element on the deposited layer in step (v), in particular when the aerosol generating material has a powdered or crumbed form.

Step (ii) may comprise providing a metal foil and may comprise cutting the metal foil, for example with a cutting member, to form a ring-shaped susceptor element or a plurality of ring-shaped susceptor elements. The use of a metal foil and cutting member to form the susceptor element(s) may facilitate the mass-production of aerosol generating articles. Cutting may include punching, laser cutting, plasma cutting, water jet cutting or etching (e.g. photoetching or chemical etching). The cup may include a cup axis extending between the open end and the bottom wall and step (vi) may include positioning respectively second and third inductively heatable susceptor elements in the cup at even distances from respectively the first and second inductively heatable susceptor elements in the direction of the cup axis. A uniform distribution of the inductively heatable susceptor elements throughout the plant-based aerosol generating material is thereby obtained and this in turn ensures a uniform transfer of heat from the inductively heatable susceptor elements to the plant-based aerosol generating material during use of the aerosol generating article with an aerosol generating device.

Step (vii) may comprise affixing the closure on the flange by gluing or welding. Step (vii) may comprise affixing the closure on the flange by a snap-fit connection. The closure can be securely and reliably affixed to the flange, thereby ensuring that the aerosol generating material and the inductively heatable susceptor element(s) are retained in the cup and facilitating mass production of aerosol generating articles.

The cup may include a positioning member for receiving the inductively heatable susceptor element. Step (v) may include positioning the inductively heatable susceptor element by the positioning member. The inductively heatable susceptor element can be easily and reliably positioned in the cup in a predetermined position with respect to the aerosol generating material, thereby ensuring that uniform heating of the aerosol generating material can be achieved. The use of a positioning member can also help to ensure that the inductively heatable susceptor element is correctly positioned for coupling with an electromagnetic field during use of the aerosol generating article with an aerosol generating device, thereby ensuring that maximum heat generation is achieved in the inductively heatable susceptor element.

The positioning member may comprise a retaining surface which may extend continuously in a circumferential direction of an inside wall of the cup. With this arrangement, the inductively heatable susceptor element is reliably supported around its periphery. The positioning member may comprise at least two, preferably three or more, separate retaining surfaces at circumferentially spaced locations inside the cup. With this arrangement, the periphery of the inductively heatable susceptor element is supported at discrete circumferential positions, thereby increasing the contact area between the aerosol generating material and the inductively heatable susceptor element around its periphery and maximising the amount of heat transfer to the aerosol generating material.

Step (v) may comprise positioning the inductively heatable susceptor element on the retaining surface or surfaces.

The cup may include a cup axis extending between the open end and the bottom wall and at least two of said positioning members at different locations along the cup axis. The positioning member located along the cup axis nearest to the open end may be closer to an inside wall of the cup than the other positioning member(s). The positioning members ensure that a uniform distribution of the inductively heatable susceptor elements throughout the plant-based aerosol generating material can be achieved and this in turn ensures a uniform transfer of heat from the inductively heatable susceptor elements to the plant-based aerosol generating material during use of the aerosol generating article with an aerosol generating device.

The cup may further comprise a stopper extending from the side wall in a radially inward direction. The stopper facilitates reliable and accurate positioning of the inductively heatable susceptor element in the cup in a direction orthogonal to the cup axis, for example in the radial direction.

The side wall of the cup may include a step which includes the stopper and the positioning member. This provides a simple and robust structure.

The cup may include a cup axis extending between the open end and the bottom wall. Step (v) may include placing the inductively heatable susceptor element in the cup substantially in the direction of the cup axis by contacting the inductively heatable susceptor element with a positioning member inside the cup. The method may further comprise withdrawing the positioning member from the cup after placing the inductively heatable susceptor element in the cup. With this arrangement, the positioning member does not form part of the cup. The cup may, therefore, be easier and cheaper to manufacture than a cup in which the positioning member forms part of the cup. Further, the positioning member could be inserted through an existing opening in the bottom wall (e.g. an opening intended to allow air to flow through the bottom wall), thereby facilitating the insertion and removal of the positioning member.

The plant-based aerosol generating material may be any type of solid or semi-solid material capable of generating vapour and/or aerosol upon heating. As noted above, the aerosol generating material may include granules, pellets, shreds, strands, particles, gel, strips, loose leaves, cut leaves, cut filler, porous material, foam material or sheets or combinations thereof. The plant-based aerosol generating material may comprise tobacco. It may advantageously comprise reconstituted tobacco.

The foam material may comprise a plurality of fine particles (e.g. tobacco particles). The tobacco particles may have a particle size (D90) between 50 and 180 pm, preferably between 60 and 140 pm, further preferably between 65 and 125 pm, even further preferably between 70 and 110 pm, particularly preferably between 75 and 90 pm, e.g. having a particle size (D90) of about 80 pm. The particle size in volume (D90) is determined by dry dispersion of the sample and laser refractometry using the Malvern Mastersizer 3000.

The foam material may further comprise an aerosol forming agent such as propylene glycol, glycerol and a combination thereof. The aerosol forming agent can further comprise water. Water can be contained in an amount of 0 to 15 wt.% of the weight of the foam material, e.g. 5 to 10 wt.%. The foam material may further comprise a solvent and/or an acid and/or an ester in an amount of up to 15 wt.%, based on the total weight of the foam material, preferably up to 5 wt.%. The foam material may further comprise a foam forming agent such non-protein containing polysaccharide. The foam material may further comprise a foam stabilizing agent such as cellulose gum. The foam material may be porous, which is open-pored, and may allow a flow of air and/or vapour through the foam material.

The plant-based aerosol generating material may comprise an aerosol-former. The aerosol former acts as a humectant. Examples of aerosol-formers include polyhydric alcohols and mixtures thereof such as glycerine or propylene glycol. The aerosol generating material may comprise an aerosol-former content of between approximately 5% and approximately 50% on a dry weight basis. In some embodiments, the aerosol generating material may comprise an aerosol-former content of between approximately 30% and approximately 50% on a dry weight basis, and possibly approximately 40% on a dry weight basis.

Upon heating, the plant-based aerosol generating material may release volatile compounds. The volatile compounds may include nicotine or flavour compounds such as tobacco flavouring.

Steps (iv), (v) and (vii), and optional step (vi), may be carried out on a turntable. The use of a turntable allows the plant-based aerosol generating material and the inductively heatable susceptor element(s) to be positioned accurately and reliably in the cup. The use of a turntable may be particularly advantageous in embodiments in which step (vi) is carried out to alternately position layers of the plant-based aerosol generating material and the inductively heatable susceptor elements in the cup. In other possible embodiments, steps (iv), (v) and (vii), and optional step (vi), may be carried out on a linear conveyor.

According to a second aspect of the present disclosure, there is provided apparatus for manufacturing an aerosol generating article according to the method defined above, wherein the apparatus comprises:

a cup holding unit for holding a plurality of cups;

a first station comprising a dosing and depositing unit for depositing dosed layers of plant-based aerosol generating material in the cups; a second station comprising a foil receiving unit for receiving a metal foil and a cutting unit for cutting heatable inductively susceptor elements from the metal foil, the second station further comprising a placing unit for placing the inductively heatable susceptor elements in the cups; and

a third station comprising a closure receiving unit and a sealing unit for affixing the closures on the flanges of the cups.

The use of such apparatus facilitates mass production of the aerosol generating articles, in particular by moving the cup holding unit between the first, second and third stations.

The cutting unit may comprise a punching unit for punching ring-shaped susceptor elements from the metal foil. The use of a punching unit lends itself well to mass production. The cutting unit may alternatively comprise a laser cutting unit, a plasma cutting unit, a water jet cutting unit or an etching unit (e.g. a photoetching unit or a chemical etching unit).

The sealing unit may comprise an adhesive applicator for applying a layer of adhesive between the closures and the flanges of the cups. The sealing unit ensures that the closures can be reliably secured to the flanges of the cups.

The cup holding unit may comprise a transport unit for moving the cups between the first, second and third stations. The transport unit may be configured to move the cup holding unit back and forth between the first and second stations a desired number of times to deposit a plurality of layers of plant-based aerosol generating material in the cups and to place a plurality of inductively heatable susceptor elements in the cups.

The cup holding unit may comprise a sliding tray. The cups can be moved easily by the sliding tray between the first, second and third stations.

The cup holding unit may comprise a turntable. The cup holding unit may comprise a tray moved by a linear conveyor. The apparatus may comprise a controller which may be configured to control the operation of one or more of the cup holding unit, the first station, the second station and the third station.

Brief Description of the Drawings

Figure 1 is diagrammatic cross-sectional side view of an aerosol generating article comprising a first example of a cup containing a plant-based aerosol generating material and a plurality of ring-shaped inductively heatable susceptor elements;

Figure 2 is a plan view of one of the ring-shaped inductively heatable susceptor elements;

Figure 3a is a plan view of a second example of a cup;

Figure 3b is a cross-sectional view along the line A-A in Figure 3a;

Figure 3c is a side view of the cup of Figures 3a and 3b;

Figure 3d is a perspective view of the cup of Figures 3a to 3c;

Figures 4a and 4b are diagrammatic cross-sectional side views of an aerosol generating article similar to that shown in Figure 1, showing a first example of a snap-fit connection between the cup and a closure;

Figures 5 a and 5b are diagrammatic cross-sectional side views of an aerosol generating article similar to that shown in Figure 1, showing a second example of a snap-fit connection between the cup and a closure;

Figure 6 is a flowchart illustrating the steps of a method for manufacturing an aerosol generating article;

Figures 7a and 7b are respectively a diagrammatic cross-sectional side view and a diagrammatic plan view of a cup including positioning members which extend continuously around the inner surface of a side wall of the cup;

Figures 8a to 8h are schematic illustrations of an example of a method for manufacturing an aerosol generating article using the cup of Figures 7 a and 7b;

Figure 9a is a diagrammatic plan view of a cup including positioning members at discrete circumferential locations around the inner surface of the side wall of the cup; Figures 9b and 9c are diagrammatic cross-sectional views respectively along the lines A-A and B-B in Figure 9a prior to filling the cup with plant-based aerosol generating material and inductively heatable susceptor elements; Figures lOa and lOb are diagrammatic cross-sectional views respectively along the lines A-A and B-B in Figure 9a after filling the cup with plant-based aerosol generating material and inductively heatable susceptor elements;

Figures l la and l lb are respectively a diagrammatic cross-sectional side view and a diagrammatic plan view of a cup including removable positioning members;

Figures l2a to l2i are schematic illustrations of an example of a method for manufacturing an aerosol generating article using the cup of Figures l la and l lb; and Figure 13 is a schematic view of an apparatus for manufacturing an aerosol generating article according to the method of Figure 6.

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.

Referring initially to Figures 1 and 2, there is shown a first example of an aerosol generating article 1 for use with an aerosol generating device comprising an electromagnetic field generator (e.g. an induction heating system comprising an induction coil). The aerosol generating article 1 comprises a first example of a cylindrical cup 10 having a substantially circular bottom wall 12, a substantially cylindrical side wall 14 and a substantially circular open end 16 sealed by a substantially circular closure 18 affixed to a flange 20 at the open end 16 of the cup 10.

The cylindrical cup 10 is typically a paper cup, for example a moulded paper cup having a self-supporting moulded form. The bottom wall 12 is air-permeable and in the illustrated embodiment includes a plurality of openings or perforations 22. In some embodiments, the paper (or other material) from which the cup 10 is manufactured may have a porous structure which allows air to flow through the bottom wall 12 without the need for the openings or perforations 22.

The cup 10 contains a plant-based aerosol generating material 24, for example a solid or semi-solid material which has a powdered or crumbed form with a sieved particle size less than 1.7 mm. The plant-based aerosol generating material 24 also comprises an aerosol-former, such as glycerine or propylene glycol, which acts as a humectant. Typically, the plant-based aerosol generating material 24 may comprise an aerosol- former content of between approximately 30% and approximately 50% on a dry weight basis, and possibly approximately 40% on a dry weight basis. Upon being heated, the plant-based aerosol generating material 24 releases volatile compounds possibly including nicotine or flavour compounds such as tobacco flavouring.

The cup 10 also contains a plurality of ring-shaped inductively heatable susceptor elements 26. The inductively heatable susceptor elements 26 are arranged coaxially inside the cylindrical cup 10 with respect to a cup axis extending between the bottom wall 12 and the open end 16 and are spaced apart in the axial direction along the cup axis. When an alternating electromagnetic field is applied in the vicinity of the inductively heatable susceptor elements 26 during use of the article 1 in an aerosol generating device, heat is generated in the inductively heatable susceptor elements 26 due to eddy currents and magnetic hysteresis losses and the heat is transferred from the inductively heatable susceptor elements 26 to the plant-based aerosol generating material 24 to heat the plant-based aerosol generating material 24 without burning it and to thereby generate a vapour which cools and condenses to form an aerosol for inhalation by a user. The inductively heatable susceptor elements 26 are in contact over substantially their entire surfaces with the plant-based aerosol generating material 24, thus enabling heat to be transferred directly, and therefore efficiently, from the inductively heatable susceptor elements 26 to the plant-based aerosol generating material 24.

The closure 18 at the open end 16 retains the plant-based aerosol generating material 24 and the inductively heatable susceptor elements 26 inside the cup 10. It will be understood by one of ordinary skill in the art that the closure 18 needs to be air- permeable so that a vapour or aerosol generated due to heating of the plant-based aerosol generating material 24 can flow out of the cylindrical cup 10 during use of the aerosol generating article 1 in an aerosol generating device. In the example illustrated in Figure 1, the flange 20 comprises an outwardly extending circular lip 28 and the closure 18 is affixed to the circular lip 28 by an adhesive or by welding, for example using an ultrasonic welding technique or a hot press.

Referring now to Figures 3 a to 3 c, there is shown a second example of a cylindrical cup 110 which is similar to the cup 10 described above with reference to Figure 1 and in which corresponding elements are designated using the same reference numerals.

As best seen in Figures 3a and 3b, the bottom wall 12 comprises a plurality of circumferentially spaced peripheral openings 30 positioned around a central opening 32. The peripheral openings 30 are substantially circular and have a diameter typically between 0.5 mm and 1 mm. The central opening 32 is also substantially circular and has a larger diameter than the peripheral openings, typically between 1.2 mm and 2.5 mm.

Referring now to Figures 4a and 4b, there is shown a second example of an aerosol generating article 2 which is similar to the aerosol generating article 1 described above with reference to Figures 1 and 2 and in which corresponding elements are designated using the same reference numerals. It will be noted that the plant-based aerosol generating material 24 and the inductively heatable susceptor elements 26 are not shown in Figures 4a and 4b.

The aerosol generating article 2 comprises a closure 18 having a snap-fit connector 34. The snap-fit connector 34 comprises a circumferentially extending hook 36 forming a circumferential recess 38 in which the flange 20 can be securely located as shown in Figure 4b. The hook 36 includes a tapered surface 40 which allows it to slide past the flange 20 when the closure 18 is moved in the direction of the cup axis from the position shown in Figure 4a to the position shown in Figure 4b. It will be understood by one of ordinary skill in the art that the side wall 14 of the cup 10 proximate the open end 16 and/or the hook 36 may flex as the closure 18 is pressed onto the flange 20 before one or both components return to their original positions, to thereby allow the flange 20 to be accommodated and securely retained in the circumferential recess 38 as shown in Figure 4b. Referring now to Figures 5a and 5b, there is shown a third example of an aerosol generating article 3 which is similar to the aerosol generating articles 1 , 2 described above with reference to Figures 1, 2, 4a and 4b and in which corresponding elements are designated using the same reference numerals. It will again be noted that the plant- based aerosol generating material 24 and the inductively heatable susceptor elements 26 are not shown in Figures 5a and 5b.

The aerosol generating article 3 comprises a cup 210 having a flange 20 which projects in the radially inward direction and forms a snap-fit connector 42. In more detail, the snap-fit connector 42 comprises an upper circumferential flange portion 44 and a lower circumferential flange portion 46 which define therebetween a circumferential recess 48 in which the periphery of the closure 18 can be securely retained as shown in Figure 5b. The upper circumferential flange portion 44 includes a tapered surface 50 which facilitates movement of the closure 18 from the position shown in Figure 5 a into the circumferential recess 48 as shown in Figure 5b. In particular, it will be understood by one of ordinary skill in the art that the side wall 14 of the cup 210 proximate the open end 16 may be caused to flex radially outwardly as the as the closure 18 is pressed onto the tapered surface 50 and that the upper circumferential flange portion 44 may also be deformed outwardly and/or downwardly before both components return to their original positions, to thereby allow the periphery of the closure 18 to be accommodated in the circumferential recess 48 as shown in Figure 5b.

Referring now to Figure 6, there is shown an example of a method for manufacturing an aerosol generating article, for example the first example of the aerosol generating article 1 described above with reference to Figures 1 and 2.

In first, second and third steps Sl, S2 and S3, the method comprises respectively providing plant-based aerosol generating material 24, providing an inductively heatable susceptor element 26 and providing a cup 10, 110, 210 comprising a bottom wall 12, a side wall 14 and a flange 20 at an open end 16. The inductively heatable susceptor element 26 in step S2 is preferably provided by punching a continuous susceptor element, preferably a metal foil, most preferably an aluminium foil, to form one or more ring-shaped susceptor elements 26 as described above with reference to Figures 1 and 2.

In a fourth step S4, a layer of the plant-based aerosol generating material 24 is deposited in the cup 10, 110, 210. The layer of plant-based aerosol generating material 24, which typically has a powdered or crumbed form as discussed above, is dosed (for example weighed) and deposited in the cup 10, 110, 210 to ensure that the deposited layer contains a predetermined amount (e.g. mass) of the aerosol generating material 24. In some embodiments, the mass of the aerosol generating material 24 in the deposited layer may be between 40 mg and 60 mg, for example approximately 50 mg. In an optional step, the method may comprise flattening the deposited layer of the plant-based aerosol generating material 12. The flattening is ideally carried out without pressing the deposited layer of the plant-based aerosol generating material 12 to avoid compaction of the aerosol generating material 12.

In a fifth step S5, an inductively heatable susceptor element 26 as provided in step S2 is placed on the layer of plant-based aerosol generating material 24 deposited in the cup in step S4.

In an optional step S6, a further layer of the plant-based aerosol generating material 24 can be dosed and deposited in the cup 10 (i.e. step S4 only can be repeated) or a further layer of the plant-based aerosol generating material 24 can be dosed and deposited in the cup 10 and an inductively heatable susceptor element 26 can be placed on the further layer of plant-based aerosol generating material 24 (i.e. both steps S4 and S5 can be repeated a desired number of times to provide a plurality of alternating layers of the plant-based aerosol generating material 24 and inductively heatable susceptor elements 26).

In a final step S7, a closure 18 is provided and the closure 18 is affixed on the flange 20, for example by gluing or welding the closure 18 on the flange 20 as described above with reference to Figures 1 to 3 or by a snap-fit connection as described above with reference to Figures 4 and 5.

Referring now to Figures 7a and 7b, there is shown an example of a cup 310 in which the side wall 14 has a stepped inner surface 52 comprising a plurality of steps 54a-c.

The steps 54a-c define a plurality of radially extending retaining surfaces 56a-c which extend continuously in a circumferential direction of the inside wall 58 of the cup 310. The retaining surfaces 56a-c act as positioning members 56 for positioning the inductively heatable susceptor elements 26 axially in the cup 310, along the cup axis, as will be described below with reference to Figures 8a-h. Due to the stepped configuration of the inner surface 52, the retaining surface 56c positioned along the cup axis nearest to the open end 16 is closer to the side wall 14 than the retaining surfaces 56a, 56b below it. Similarly, the retaining surface 56b is closer to the side wall 14 than the retaining surface 56a below it. In one embodiment, the retaining surfaces 56a-c are spaced by a uniform distance.

The steps 54a-c also define a plurality of axially extending abutment surfaces 60a-c which extend continuously in a circumferential direction of the inside wall 58 of the cup 310. The abutment surfaces 60a-c act as stoppers 60 for positioning the inductively heatable susceptor elements 26 radially in the cup 310, for example so that they are coaxial with the cup axis, as will be described below with reference to Figures 8a-h. Due to the stepped configuration of the inner surface 52, the abutment surface 60c positioned along the cup axis nearest to the open end 16 is closer to the side wall 14 than the abutment surfaces 60a, 60b below it. Similarly, the abutment surface 60b is closer to the side wall 14 than the abutment surface 60a below it.

Referring now to Figures 8a-h, a first layer 24a of plant-based aerosol generating material 24 is dosed and deposited in the cup 310 as shown in Figure 8a and in accordance with step S4 described above. A first inductively heatable susceptor element 26a is then placed on the deposited first layer 24a of plant-based aerosol generating material 24a as shown in Figure 8b and in accordance with step S5 described above. The inductively heatable susceptor element 26a contacts the retaining surface 56a and the abutment surface 60a and is thereby positioned in predetermined axial and radial positions inside the cup 310. Further layers of plant-based aerosol generating material 24b-d and further inductively heatable susceptor elements 26b-c are then placed in the cup 310 as shown in Figures 8c to 8g in accordance with step S6 described above.

In particular, a second layer 24b of plant-based aerosol generating material 24 is dosed and deposited in the cup 310 as shown in Figure 8c and a second inductively heatable susceptor element 26b is then placed in the cup 310 in contact with the retaining surface 56b and the abutment surface 60b as shown in Figure 8d. The second inductively heatable susceptor element 26b has a larger outer diameter than the first inductively heatable susceptor element 26a so that it can contact the surfaces 56b, 60b.

A third layer 24c of plant-based aerosol generating material 24 is then dosed and deposited in the cup 310 as shown in Figure 8e and a third inductively heatable susceptor element 26c is then placed in the cup 310 in contact with the retaining surface 56c and the abutment surface 60c as shown in Figure 8f. The third inductively heatable susceptor element 26c has a larger outer diameter than the first and second inductively heatable susceptor elements 26a, 26b so that it can contact the surfaces 56c, 60c.

A fourth and final layer 24d of plant-based aerosol generating material 24 is then dosed and deposited in the cup 310 as shown in Figure 8g so that the cup 310 is completely filled with the plant-based aerosol generating material 24 and the inductively heatable susceptor elements 26. The closure 18 is then affixed to the flange 20 in accordance with step S7 described above to secure the plant-based aerosol generating material 24 and the inductively heatable susceptor elements 26 inside the cup 310 and thereby form an aerosol generating article. Referring now to Figures 9a to 9c and 10 to lOb, there is shown an example of a cup 410 in which includes a plurality of stepped segments 62 at circumferentially spaced locations inside the cup. Each stepped segment 62 includes a plurality of steps 64a-c.

The steps 64a-c define a plurality of radially extending retaining surfaces 66a-c which act as positioning members 66 for positioning the inductively heatable susceptor elements 26a-c axially in the cup 410, along the cup axis, as described above with reference to Figures 8a-h and as shown in Figures lOa and lOb. The steps 64a-c also define a plurality of axially extending abutment surfaces 68a-c which act as stoppers 68 for positioning the inductively heatable susceptor elements 26a-c radially in the cup 410, as also described above with reference to Figures 8a-h and as shown in Figures lOa and lOb.

Referring now to Figures 1 la and 1 lb, there is shown an example of a cup 510 which uses removable positioning members 70 for positioning the inductively heatable susceptor elements 26 inside the cup 510 as shown in Figures l2a-i. The positioning members 70 comprise pins 72 which extend in the axial direction through openings 22 in the bottom wall 12 that are intended to facilitate air flow through the bottom wall 12 during use of the aerosol generating article in an aerosol generating device. In the illustrated example, three circumferential arrays of 72a-c of the pins 72 are inserted through openings 22 in the bottom wall 12 so that the ends of the pins 72 in each array 72a-c are located at different axial and radial positions inside the cup 510. In the illustrated example, each array 72a-c comprises four pins 72 as best seen in Figure 1 lb, but in practice each array could comprise two or more pins 72.

After the pins 72 have been inserted through the openings 22 in the bottom wall 12, a first layer 24a of plant-based aerosol generating material 24 is dosed and deposited in the cup 310 as shown in Figure l2a and in accordance with step S4 described above. A first inductively heatable susceptor element 26a is then placed on the deposited first layer 24a of plant-based aerosol generating material 26 as shown in Figure 8b and in accordance with step S5 described above. The inductively heatable susceptor element 28a contacts the ends of the pins 72 in the first array 72a and the sides of the pins 72 in the second array 72b. The ends of the pins 72 in the first array 72a act as retaining surfaces and sides of the pins 72 in the second array 72b act as abutment surfaces, thereby positioning the first inductively heatable susceptor element 26a in predetermined axial and radial positions inside the cup 510.

Further layers of plant-based aerosol generating material 24b-d and further inductively heatable susceptor elements 26b-c are then placed in the cup 510 as shown in Figures l2c to l2g in accordance with step S6 described above. The method is similar to that described above with reference to Figures 8c to 8g and will not be described in further detail.

After the fourth and final layer 24d of plant-based aerosol generating material 24 has been dosed and deposited in the cup 510 as shown in Figure l2g, the closure 18 is affixed to the flange 20 in accordance with step S7 described above to secure the plant- based aerosol generating material 24 and the inductively heatable susceptor elements 26 inside the cup 510. Finally, the circumferential arrays 72a-c of pins 72 are withdrawn from the openings 22 in the bottom wall 12 as shown in Figure l2i to form an aerosol generating article.

Referring now to Figure 13, there is shown a schematic view of an apparatus 80 for performing the methods described above. The apparatus 80 comprises a cup holding unit 82 for holding a plurality of cups, and first to third stations 84, 86, 88. The cup holding unit 82 may comprise a sliding tray and a transport unit (not shown) for moving the sliding tray between the first, second and third stations 84, 86, 88 as shown schematically in Figure 13.

The first station 84 comprises a dosing and depositing unit for depositing dosed layers of plant-based aerosol generating material 24 in the cups held by the cup holding unit 82. The second station 86 comprises a foil receiving unit for receiving a metal foil and a cutting unit, for example a punching unit, for punching the metal foil to form ring- shaped inductively heatable susceptor elements 26 as described above. The second station 86 also comprises a placing unit for placing the ring-shaped inductively heatable susceptor elements 26 in the cups held by the cup holding unit 82. The third station 88 comprises a closure receiving unit and a sealing unit, such as an adhesive applicator for applying a layer of adhesive between the closures 18 and the flanges 20 of the cups to enable the closures 18 to be affixed on the flanges 20 of the cups.

The apparatus 80 comprises a controller (not shown) configured for controlling the operation of the transport unit, and for thereby controlling the movement of the sliding tray between the first, second and third stations 84, 86, 88. The controller is also configured for controlling the operation of the first, second and third stations 84, 86, 88.

In operation, the cup holding unit 82 loaded with cups is positioned at the first station 84 by the transport unit so that a first layer of plant-based aerosol generating material 24 can be dosed and deposited in the cups in accordance with step S4 described above. The cup holding unit 82 is then moved by the transport unit under the operation of the controller to the second station 86 so that inductively heatable susceptor elements 26 can be placed in the cups in accordance with step S5 described above. The cup holding unit 82 can, if desired, be moved by the transport unit under the action of the controller back to the first station 84 so that a second layer of plant-based aerosol generating material 24 can be dosed and deposited in the cups in accordance with step S4 described above. The cup holding unit 82 can be moved back and forth between the first and second stations 84, 86 by the transport unit, under the action of the controller, a desired number of times to provide a desired number of layers of the plant-based aerosol generating material 24 and a desired number of the inductively heatable susceptor elements 26 in the cups. Finally, the cup holding unit 82 is moved by the transport unit under the action of the controller to the third station 88 where a closure 18 is affixed on the flange 20 of each of the cups in the cup holding unit 82 to thereby provide a plurality of aerosol generating articles which can then be removed from the cup holding unit 82.

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”.