WO2024240668A1

WO2024240668A1 - Particle-shaped aerosol-generating article with distributed susceptor material

Info

Publication number: WO2024240668A1
Application number: PCT/EP2024/063745
Authority: WO
Inventors: Rui Nuno Rodrigues Alves BATISTA; Lucia JIMENEZ-YANGUAS PRINI; Hau Man CHENG
Original assignee: Philip Morris Products S.A.
Priority date: 2023-05-19
Filing date: 2024-05-17
Publication date: 2024-11-28

Abstract

The invention relates to an aerosol-generating article (10) for an aerosol-generating device, wherein the aerosol-generating article (10) is in the shape of a particle. The aerosol-generating article (10) comprises a first aerosol-generating substrate (16) and a plurality of pieces of susceptor material (18). The plurality of pieces of susceptor material (18) are distributed throughout the first aerosol- generating substrate (16). The invention further relates to a method of manufacturing such aerosol-generating article (10).

Description

Particle-shaped aerosol-generating article with distributed susceptor material

The present disclosure relates to an aerosol-generating article for an aerosol-generating device, wherein the aerosol-generating article is in the shape of a particle and a method of forming an aerosol-generating article in the shape of a particle.

Aerosol-generating articles generating an aerosol from an aerosol-generating substrate without requiring combustion of the aerosol-generating substrate are known. Such articles are often designated as “heat-not-burn” aerosol-generating articles, since an aerosol-generating substrate is heated to a relatively low temperature to induce the formation of an aerosol but prevent the combustion of material contained within the aerosol-generating substrate.

Known aerosol-generating substrates are typically not heatable to operating temperatures by induction. This means that, for inductive heating, a separate susceptor element is typically required. Where an inductively heated susceptor element is placed in a central position in the aerosol-generating substrate, portions of the aerosol-generating substrate which are located furthest from the susceptor element may not reach a temperature sufficiently high for releasing many volatile compounds.

In addition, most of the aerosol-generating articles already existing in the market have rod shapes, reproducing the shape of standard cigarettes. Such aerosol-generating articles have a plurality of parts and different functional elements to enable its performance.

It would be desirable to have an aerosol-generating article having an improved heat contact between the aerosol-generating substrate and the susceptor element. It would also be desirable to have such aerosol-generating article requiring a simpler manufacturing process than for rod shape aerosol-generating articles, in which a plurality of parts needs to be assembled in a certain sequence.

According to an aspect of the present invention, there is provided an aerosol-generating article for an aerosol-generating device, wherein the aerosol-generating article is in the shape of a particle or has a spherical shape or has a granular shape formed by a granulation process. The aerosol-generating article comprises a first aerosol-generating substrate and a plurality of pieces of susceptor material. The plurality of pieces of susceptor material are distributed throughout the first aerosol-generating substrate.

The first aerosol-generating substrate may be a substrate capable of releasing upon heating volatile compounds, which can form an aerosol. The distribution of the plurality of pieces of susceptor material throughout the first aerosol-generating substrate of the aerosolgenerating article having a particle-shape provides a direct physical contact between the first aerosol-generating substrate and each piece of susceptor material. Each piece of susceptor may thus respectively transfer heat to the first aerosol-generating substrate. This may provide a more even temperature distribution throughout the first aerosol-forming substrate during use than in an article wherein one piece of susceptor is centrally arranged in the aerosol-generating substrate. In the present aerosol-generating article, a greater proportion of the first aerosolforming substrate reaching a sufficiently high temperature to release volatile compounds may thus be achieved, and therefore a higher usage efficiency of the first aerosol-forming substrate.

The aerosol-generating article may be directly usable in an electrically heated aerosol generating device, in particular without requiring assembly with other elements to form an aerosol-generating article, like a rod-shape article, or a forming step to fit into a capsule. It may improve the sustainability of the aerosol-generating article in that a limited amount of components, namely the first aerosol-forming substrate and the plurality of pieces of susceptor material, are sufficient for providing an aerosol-generating article that is readily consumable, in particular with an electrically heated aerosol generating device.

The aerosol-generating article may be in a solid state. A solid state may be defined as a state in which a material is not fluid but retains its boundaries without support. In the solid state, the material retains its shape or substantially returns to its shape after elastic deformation. In particular, the shape of the aerosol-generating article in the final state may remain firm and stable even upon handling by a user for consumption with an aerosol generating device.

The aerosol-generating article may have a longest dimension being less than twice the shortest dimension of the aerosol-generating article. The aerosol-generating article may have a convex shape, in particular a spherical shape or an ellipsoid shape. An ellipsoid shape is a quasi-spherical shape, such as an egg shape. Alternatively, the aerosol-generating article may have an angular shape. A surface of the aerosol-generating article may be angular or rough.

The external surface of the aerosol-generating article, or at least an external coating covering the aerosol-generating article, may have an anti-adhesion property. The antiadhesion property may allow preventing a sticky sensation for a user when handling the aerosol-generating article. It may also prevent that a plurality of aerosol-generating articles adhere to each other, in particular inside a packaging, and especially under the effect of heat or moisture.

The external surface of the aerosol-generating article, or at least an external coating covering the aerosol-generating article, may promote visual or tactile identification of the aerosol-generating article. For instance, the external surface of the aerosol-generating article, or at least an external coating covering the aerosol-generating article, may be colored in accordance with the flavor or a substance content, for example nicotine content, of the aerosolgenerating substrate. Alternatively, or in combination, the external surface of the aerosolgenerating article, or at least an external coating covering the aerosol-generating article, may have a defined average surface roughness. The average surface roughness may be defined by selecting the granulometry of the materials and compounds for producing the aerosolgenerating article by granulometry. The root mean square average of profile height deviations from the mean line (RMS) may be obtained performing roughness measurements, in surface roughness tests. When the aerosol-generating article does not comprise an external coating, the average surface roughness of the external surface of the aerosol-generating article is related to the first or second aerosol-generating substrate, and may have an RMS roughness of 200 to 1000 microinches (5 to 25 micrometers), in particular of 200 to 900 microinches (5 to 23 micrometers), in particular of 300 to 560 microinches (8 to 14 micrometers). When the aerosol-generating article comprises an external coating, the average surface roughness of the external surface of the aerosol-generating article is related to the external coating, and may have an RMS roughness of 120 to 900 microinches (3 to 23 micrometers), in particular of 200 to 720 microinches (5 to 18 micrometers), in particular of 200 to 420 microinches (5 to 11 micrometers). RMS values may be converted, for instance, in arithmetic average of profile height deviations from the mean line (Ra) or in Center Line Average (CLA).

The particle shape of the aerosol-generating article may correspond to a granular shape. The particle shape or the granular shape may be achieved by means of a granulation process. Hence, the aerosol-generating article may be formed by a granulation process. Granulation process may improve the uniformity of the distribution of the susceptor material within the first aerosol-generating substrate. The granulation process may an agglomeration process, in particular wet granulation or dry granulation. Before a step of compression, wet granulation uses a liquid in the granulation process, in particular a binding solution, which can be removed via a drying process. The wet granulation process may comprise one or more of high shear granulation, reverse wet granulation, moisture-activated dry granulation, thermal adhesion granulation, melt granulation, freeze granulation, foam granulation or steam granulation. For wet granulation, in particular for melt granulation, a fluidized bed granulator may be used. A fluidized bed dryer may be used in combination, or in sequence, with the fluidized bed granulator. In particular, the aerosol-generating article may be formed by high shear wet granulation. High shear wet granulation may use a high-shear granulator. Single-pot granulation may combine the mixing, high-shear wet granulation and drying all in one process bowl. Dry granulation process uses the application of pressure without the intermediate use of liquid. Dry granulation process may comprise pneumatic dry granulation (PDG). Alternatively, molding, or over-molding, technologies may be used to achieve the distribution of the plurality of pieces of susceptor material throughout the first aerosol-generating substrate. The step of molding, or over-molding, may then be followed by a granulation process. The plurality of pieces of susceptor material may be conductive pieces that have the ability to convert electromagnetic energy and convert it to heat. When located in an alternating electromagnetic field, eddy currents are induced and hysteresis losses occur in the susceptor material causing heating of the susceptor. As in the aerosol-generating article the plurality of pieces of susceptor material is located in direct physical contact, and thus, in thermal contact, with the first aerosol-generating substrate, the first aerosol-generating substrate may be heated by the susceptor material such that an aerosol may be formed.

The plurality of pieces of susceptor material may be of different shape from one another. The plurality of pieces of susceptor material may be susceptor granules, susceptor beads, susceptor grits, susceptor flakes, susceptor fibers, susceptor rod or a combination thereof. The pieces of susceptor material, in particular the susceptor granules, susceptor beads, susceptor grits and susceptor flakes, may be manufactured from melting a raw material, for example an alloy, to create metal droplets. The raw material may comprise recycling material, for example industrial residues of stainless steel processing factories. The metal droplets may be shaped and sieved to obtain a specific granulometry range. The metal droplets may be crushed into particles, in particular angular particles, and sieved to obtain a specific granulometry range. Susceptor flakes may have substantially flat shape. Susceptor flakes may be manufactured, for example, by milling techniques using various raw material including recycling material. The pieces of susceptor material may be manufactured by a process allowing obtaining a defined thickness and overall sizing range. The process of manufacturing the pieces of susceptor material may comprise a step of preventing that the susceptor pieces to agglomerate. Alternatively or in combination, the process of manufacturing the pieces of susceptor material may comprise a step of verifying that the susceptor pieces do not agglomerate. The greatest dimension of one piece of susceptor material may be comprised between 0.1 millimeters and 2.5 millimeters, in particular between 0.25 millimeters and 1.85 millimeters, more in particular between 0.45 millimeters and 1.55 millimeters. The plurality of pieces of susceptor material may be of different size from one another.

The susceptor material may be one of paramagnetic, ferromagnetic or ferromagnetic material. The susceptor material may comprise metal. The susceptor material may comprise one of aluminum, iron, nickel, copper, bronze, cobalt, plain-carbon steel, stainless steel, ferritic stainless steel, martensitic stainless steel, or austenitic stainless steel. The susceptor material may comprise Inconel alloys (austenite nickel-chromium- based superalloys). The susceptor material may comprise transition metals such as for example Fe, Co, Ni, or metalloids components such as for example B, C, Si, P, Al. The susceptor material may comprise mumetal or permalloy. The susceptor material may comprise or be made of a carbon material. The susceptor material may comprise or be made of graphite, molybdenum, silicon carbide, niobium, ceramics such as for example zirconia. The susceptor material may be heated to a temperature in excess of 250 degrees Celsius.

The plurality of pieces of susceptor material may comprise pieces of a first susceptor material and pieces of at least a second susceptor material. The first susceptor material and the at least second susceptor material may have different properties, in particular different electrical conductivity or thermal conductivity. The first susceptor material may have a Curie temperature that is above the ignition point of the first aerosol-generating substrate. The second susceptor material may have a Curie temperature that is below the ignition point of the first aerosol-generating substrate. The first susceptor material may be used to heat the first aerosol-generating substrate when the susceptor is placed in a fluctuating electromagnetic field. The second susceptor material may be used to indicate when the susceptor has reached a specific temperature, that temperature being the Curie temperature of the second susceptor material. In particular, materials for the second susceptor material may include nickel and nickel alloys. The heating of the first aerosol-generating substrate and the temperature control of the heating may thus be separated.

The plurality of pieces of susceptor material may be evenly distributed in the first aerosolgenerating substrate. In particular, the even distribution is a substantially even distribution. The even distribution of the pieces of susceptor material may be achieved by a granulation process for forming the aerosol-generating article. The even distribution may be effected in that the manufacturing process is free of any means for supporting an uneven distribution, such as for example an agglomeration, of the pieces of susceptor material. The distribution density of the pieces of susceptor material may be defined according to different ways. For example, the distribution density may be defined as the volume of pieces of susceptor material in the first aerosol-generating substrate as a function of the total volume of the first aerosol-generating substrate.

The first aerosol-generating substrate may comprise 10 to 40 percent per weight , in particular 15 to 30 percent per weight, of susceptor material. The percent per weight of susceptor material in the first aerosol-generating substrate may be determined on a dry weight basis. Dry weight basis may refer to the percentage per weight of a susceptor material in the first aerosol-generating substrate after removing the moisture from the aerosol-generating article.

In a final state of the aerosol-generating article, namely in a state wherein the aerosolgenerating article is ready for consumption, the moisture of the first aerosol-generating substrate may be comprised between 5 and 35 percent by weight, in particular between 10 and 25 percent by weight. The first aerosol-generating substrate may be in a solid state. This applies in particular to the aerosol-generating substrate in a final state of the aerosolgenerating article, namely in a state wherein the aerosol-generating article is ready for consumption.

The first aerosol-generating substrate may further comprise 15 to 55 percent per weight, in particular 25 to 45 percent per weight of a first compound. The first aerosol-generating substrate may further comprise 3 to 25 percent per weight, in particular 7 to 18 percent per weight of a second compound. The first compound may comprise at least one of an aerosol former, a blend of tobacco leaf, cellulose fibers, tobacco fibers and a binder. The first compound may comprise 15 to 45 percent per weight, in particular 20 to 35 percent per weight, of a blend of tobacco leaf. The blend of tobacco may comprise at least one of the tobacco type among bright tobacco, dark tobacco and aromatic tobacco. “Tobacco type” refers to one of the different varieties of tobacco, based on the distinct curing process that the tobacco undergoes before it is further processed in a tobacco product. Examples of bright tobaccos are flue-cured Brazil, Indian flue-cured, Chinese flue-cured, US flue-cured such as Virginia tobacco, and flue- cured from Tanzania. Examples of aromatic tobaccos are Oriental Turkey, Greek Oriental, semi-oriental tobacco but also fire cured, US Burley, such as Perique, and Rustica. Examples of dark tobacco are dark cured Brazil Galpao, Burley Malawi or other African Burley, sun cured or air cured Indonesian Kasturi. The blend of tobacco may have particle size comprised between 100 to 380 mesh particles, in particular between 170 to 320 mesh particles. The first compound may comprise 1 to 15 percent per weight, in particular 3 to 7 percent per weight, of cellulose fibers. The cellulose fibers in the first compound may have a length comprised between 10 to 250 micrometers, in particular between 10 to 120 micrometers. The first compound may comprise 5 to 20 percent per weight, in particular 7 to 15 percent per weight, of tobacco fibers, as filler, of any tobacco type or a blend of tobacco types, from stems or stalks, or a combination of stems and stalks. The fibers in the first compound may have a length comprised between 10 to 350 micrometers, in particular between 20 to 180 micrometers. The first compound may comprise 1 to 10 percent per weight, in particular 1 to 5 percent per weight, of a binder. The binder in the first compound may comprise or be made of natural pectins, such as fruit, namely citrus, or tobacco pectins; guar gums, land locust bean gums, such as hydroxyethyl or hydroxypropyl thereof; starches, such as modified or derivatized starches; alginate; methyl, ethyl, ethylhydroxymethyl and carboxy methyl, celluloses; dextran; and xanthan gum. In a preferred embodiment, the binder in the first compound is made of guar. The first aerosol-generating substrate may comprise at least s % per weight, in particular at least 5 % per weight, more in particular at least 10 % per weight, of aerosol former with respect to the weight of the aerosol-generating substrate. The first compound may comprise less than 45 percent per weight, in particular less than 35 percent per weight, more in particular less than 25 percent per weight, of an aerosol former. The aerosol former in the first compound may be glycerine; monohydric alcohols like menthol, polyhydric alcohols, such as triethylene glycol; esters of polyhydric alcohols, such as glycerol mono-, di- or triacetate; and aliphatic esters of mono-, di- or polycarboxylic acids, such as dimethyls of those.

The first aerosol-generating substrate may further comprise a humectant, such as glycerol, propylene glycol or triethylene glycol.

The first aerosol-generating substrate may comprise at least a flavor substance. The flavor substance may be at least partially absorbed into the first aerosol-generating substrate. The flavor substance may comprise at least one flavoring component. The flavor substance may be natural, for example natural menthol. Alternatively, the flavor substance may be artificially based, for example synthetic menthol. The flavor substance may comprise essential oil. The flavor substance may comprise at least one of an organic botanical glycerite, an organic botanical extract and a botanical essential oil. The flavor substance may comprise allyl hexanoate, benzyl alcohol, citral, ethanol, itsea cubeba oils, lemon oil, lime oil, L-menthol, menthol, mint such as peppermint or spearmint, orange oils sweet, orange oil terpeneless, orange oil terpenes, tangerine oils terpene-free, tobacco flavor, or a combination thereof. The second compound may comprise the flavor substance.

The second compound may comprise between 10 to 40 percent per weight, in particular 20 to 30 percent per weight, of glycerin. The second compound may comprise between 10 to 30 percent per weight, in particular 15 to 25 percent per weight, of organic fibers. The organic fibers in the second compound may comprise or be made of cotton, wood or tea botanical. The organic fibers in the second compound may have a length comprised between 10 to 400 micrometers, in particular between 10 to 200 micrometers. The second compound may comprise between 15 to 55 percent per weight, in particular 20 to 35 percent per weight, of organic botanical glycerite. The organic botanical glycerite in the second compound may be derived from botanicals such as clove, Echinacea sp., fennel, ginger, hawthorn berry, elderberry, monarda, mullein leaves, nettle, plantain, turmeric, yarrow, and compounds of those. The second compound may comprise between 1 to 15 percent per weight, in particular 2 to 7 percent per weight of organic botanical extracts. The organic botanical extracts may be derived from menthol (dl-Menthol, C10H20O, 2-lsopropyl-5-methylcyclohexanol) such as obtained from Chaerophyllum macrospermum, Mesosphaerum sidifolium, or other related botanic varieties, as well as P-menthan-3-ol, as any secondary alcohol as diastereoisomers of 5-methyl-2-(propan-2-yl)cyclohexan-1-ol. The organic botanical extracts may be derived from botanicals such as clove, Echinacea sp., fennel, ginger, hawthorn berry, elderberry, monarda, mullein leaves, nettle, plantain, turmeric, yarrow, and compounds of those. Alternatively, the second compound may comprise between 0.5 to 5 percent per weight, in particular 1 to 3 percent per weight of botanical essential oil. The botanical essential oil may be palm, coconut or wooden-based essential oil.

The aerosol-generating article may further comprise a second aerosol-generating substrate. The first aerosol-generating substrate may be coated with the second aerosolgenerating substrate. The second aerosol-generating substrate may be in a solid state. This applies in particular to the second aerosol-generating substrate in a final state of the aerosolgenerating article, namely in a state wherein the aerosol-generating article is ready for consumption.

The second aerosol-generating substrate may have a greatest thickness comprised between 0.5 millimeters and 5 millimeters, in particular between 1 millimeter and 4 millimeters. The aerosol-generating article may be characterized by an absence of susceptor material in the second aerosol-generating substrate.

The first aerosol-generating substrate may be formed by wet granulation or dry granulation. The second aerosol-generating substrate may be formed by dry granulation.

The first aerosol-generating substrate may be configured to generate at least 60%, in particular at least 80%, of the total volume of the aerosol generated by the heated aerosolgenerating article. The second aerosol-generating substrate may be configured to generate less than 40% of the total volume of the aerosol generated by the heated aerosol-generating article.

An intermediate layer may be applied between the first aerosol-generating substrate and the second aerosol-generating substrate. The aerosol-generating article may further comprise at least an additional aerosol-generating substrate. At least one of: the intermediate layer and any additional aerosol-generating substrates may be in a solid state. This applies in particular in a final state of the aerosol-generating article, namely in a state wherein the aerosolgenerating article is ready for consumption, The second aerosol-generating substrate may be coated with the at least one additional aerosol-generating substrate. At least one the aerosolgenerating substrates may comprise a cannabinoid compound selected from the group consisting of: tetrahydrocannabinol (THC), tetrahydrocannabinolic acid (THCA), cannabidiol (CBD), cannabidiolic acid (CBDA), cannabinol (CBN), cannabigerol (CBG), cannabigerol monomethyl ether (CBGM), cannabivarin (CBV), cannabidivarin (CBDV), tetrahydrocannabivarin (THCV), cannabichromene (CBC), cannabicyclol (CBL), cannabichromevarin (CBCV), cannabigerovarin (CBGV), cannabielsoin ( BE), cannabicitran (CBT) and combinations thereof.

The plurality of aerosol-generating substrates may differ in at least one of composition, porosity, moisture content, coating thickness or shape of coating surface. The first aerosolgenerating substrate may have a moisture content of 5 to 35 percent per weight, in particular of 10 to 25 percent per weight. The second aerosol-generating substrate may have a moisture content of 5 to 20 percent per weight, in particular of 7 to 12 percent per weight.

The porosity of the second aerosol-generating substrate may be greater than the porosity of the first aerosol-generating substrate. The value of the porosity may be defined by the ratio of the pore volume of a defined volume of material with respect its total volume. The porosity of the second aerosol-generating substrate may be at least 1 .5 times the porosity of the first aerosol-generating substrate. The porosity of the second aerosol-generating substrate may be comprised between 30 to 80 percent, in particular between 40 to 70 percent, more in particular between 45 to 55 percent. The specific porosity of each of the aerosol-generating substrate may be defined by the incorporation of fiber-based materials in the respective aerosolgenerating substrate, in particular biodegradable fiber-based materials. The size of the fibers may differ between the first and the second aerosol-generating substrates. The difference of porosity may enable the airflow of an aerosol generated by the heating of the first aerosolgenerating substrate to pass through the second aerosol-generating substrate. The greater porosity of the second aerosol-generating substrate may thus enable the aerosol, generated by the heating of the first aerosol-generating substrate, to be flushed by the air surrounding the aerosol-generating article, which may then be inhaled by a user. The first aerosolgenerating substrate may thus have the function of generating most of the aerosol content or volume, in particular more of 60% of the aerosol content or volume that may be inhaled by a user. The second aerosol-generating substrate may have the main function of releasing the airflow of aerosol generated by the first aerosol-generating substrate. The airflow distribution of the aerosol of the aerosol-generating article having a particle’s shape may be defined by the selection of the second aerosol-generating substrate.

The composition of the first aerosol-generating substrate may be different from the composition of the second aerosol-generating substrate.

The second aerosol-generating substrate may comprise a greater amount of tobacco fibers than the first aerosol-generating substrate. The second aerosol-generating substrate may further comprise 3 to 15 percent per weight, in particular 5 to 10 percent per weight of the second compound as above described. The second aerosol-generating substrate may further comprise 45 to 95 percent per weight, in particular 65 to 85 percent per weight of a third compound. The third compound may comprise 15 to 55 percent per weight, in particular 20 to 40 percent per weight, of a blend of tobacco leaf. The blend of tobacco may comprise at least one of the tobacco type among bright tobacco, dark tobacco and aromatic tobacco. The blend of tobacco may have particle size comprised between 100 to 380 mesh particles, in particular between 170 to 320 mesh particles. The third compound may comprise 3 to 20 percent per weight, in particular 7 to 15 percent per weight, of cellulose fibers. The cellulose fibers in the third compound may have a length comprised between 10 to 380 micrometers, in particular between 90 to 270 micrometers. The third compound may comprise 15 to 40 percent per weight, in particular 20 to 35 percent per weight, of tobacco fibers, as filler, of any tobacco type or a blend of tobacco types, from stems or stalks, or a combination of stems and stalks. The fibers in the third compound may have a length comprised between 25 to 350 micrometers, in particular between 50 to 220 micrometers. The third compound may comprise 1 to 10 percent per weight, in particular 2 to 5 percent per weight, of a binder. The binder in the third compound may comprise or be made of natural pectins, such as fruit, namely citrus, or tobacco pectins; guar gums, land locust bean gums, such as hydroxyethyl or hydroxypropyl thereof; starches, such as modified or derivatized starches; alginate; methyl, ethyl, ethylhydroxymethyl and carboxymethyl, celluloses; dextran; and xanthan gum. In a preferred embodiment, the binder in the third compound is made of guar.

The first aerosol-generating substrate may comprise a greater amount of aerosol former than the second aerosol-generating substrate. The third compound may comprise between 1 to 15 percent per weight, in particular between 3 and 7 percent per weight, of an aerosol former. The aerosol former in the third compound may be glycerine; monohydric alcohols like menthol, polyhydric alcohols, such as triethylene glycol; esters of polyhydric alcohols, such as glycerol mono-, di- or triacetate; and aliphatic esters of mono-, di- or polycarboxylic acids, such as dimethyls of those.

The shape of the external surface of the first aerosol-generating substrate may differ from the shape of the external surface of the second aerosol-generating substrate. The second aerosol-generating substrate may define the external shape of the aerosol-generating article while the first aerosol-generating substrate may define the core of the aerosol-generating article. The overall aerosol-generating article may be in the shape of a substantially spherical particle while the first aerosol-generating substrate may be in the shape of an angular particle.

The longest dimension of the aerosol-generating article may be greater than 7 millimeters, and in particular less than 21 millimeters. The longest dimension of the aerosolgenerating article may be comprised between 7 and 16 millimeters. A longest dimension of the first aerosol-generating substrate may be comprised between 3.5 millimeters and 17 millimeters, in particular between 4 millimeters and 14 millimeters. The second aerosolgenerating substrate may have a thickness comprised between 0.5 millimeters and 5 millimeters, in particular between 1 millimeters and 4 millimeters. The particle size of the aerosol-generating article may advantageously allow a manipulation of a single aerosolgenerating article for consumption. The size of the aerosol-generating article may enable the desired amount of aerosol delivery to a consumer. In particular, the aerosol-generating article may deliver in between 5 to 20 puffs, preferably 10 to 13 puffs, more preferably 11 to 12 puffs, when consumed with an aerosol-generating device.

The aerosol-generating article may further comprise an external coating. The provision of an external coating on the first or second aerosol-generating substrate may advantageously limit the permeation of oxygen or water vapour into the aerosol-generating article, which may help to extend the shelf life of the aerosol-generating article. Alternatively or in addition, the external coating may help to protect the structural integrity of the aerosol-generating article, or to provide improved smoothness of the aerosol-generating article. The external coating may help to provide an aerosol-generating article in the shape of a particle that can be manipulated directly by the hands in a hygienic way. In certain embodiments, a relatively brittle external coating may be added to the aerosol-generating article that is adapted to be broken by the consumer prior to use. This type of external coating can therefore provide the consumer with a tactile and audible indication that the aerosol-generating article is ready for use. Alternatively or in addition, the provision of an external coating may be used to adjust the colour of the aerosol-generating article, for example, to provide a visual indication of a property of the aerosol-generating article, such as the flavour or the content of nicotine.

The external coating may be in a solid state. This applies in particular in a final state of the aerosol-generating article, namely in a state wherein the aerosol-generating article is ready for consumption, The external coating may be a porous coating. The porosity of the external coating may allow the airflow of aerosol generated in the first aerosol-generating substrate, that may optionally first pass through the second aerosol-generation substrate, to be released to the outside of the particle by passing through the pore of the external coating.

The porosity of the second aerosol-generating substrate may be greater than the porosity of the external coating. The external coating may cover the first aerosol-generating substrate or the second aerosol-generating entirely. Alternatively, the external coating may cover only partially the first aerosol-generating substrate or the second aerosol-generating substrate. The external coating may be applied according to a predetermined pattern on the first aerosolgenerating substrate or the second aerosol-generating. The material of the external coating may have an alginate-based formulation.

The material of the external coating may comprise at least one of: Alginate, Alginatemaltodextrin, Alginate-galbanum gum, Starch-alginate, crosslinking with CaCI2, CaCI2-CMC, Calcium gluconate, calcium lactate and tapioca starch. The material of the external coating may further comprise an antimicrobial substance. The material of the external coating may have anti-adhesion properties. The external coating may be biodegradable. The external coating may exclusively comprise a bio-based material. A bio-based material is a material that is created from biomass. The external coating may exclusively comprise a natural material. A natural material is a material generated from plants, animals or the ground. Alternatively, the external coating may exclusively comprise a combination of natural material and bio-based material.

The external coating may comprise or be made of vanillin, thyme oil, lemongrass extract, carvacrol, methyl cinnamate, nisin, acetic acid, lactic acid, potassium sorbate, ziziphora persica essential oil and extract(s), sodium lactate, sodium diacetate, pomegranate peel extract, lemongrass extract(s).

According to an aspect of the present invention, there is provided an aerosol-generating article for an aerosol-generating device, wherein the aerosol-generating article has a longest dimension being less than twice the shortest dimension of the aerosol-generating article. The longest dimension of the article is greater than 7 millimeters, and in particular less than 21 millimeters. The particle size of the aerosol-generating article may advantageously allow a manipulation of a single aerosol-generating article for consumption. The size of the aerosolgenerating article may enable the desired amount of aerosol delivery to a consumer. In particular, the aerosol-generating article may deliver in between 5 to 20 puffs, preferably 10 to 13 puffs, more preferably 11 to 12 puffs, when consumed with an aerosol-generating device.

According to an aspect of the present invention, there is provided a method of manufacturing an aerosol-generating article, comprising the steps of: (a) providing a first aerosol-generating substrate, (b) providing a plurality of pieces of susceptor material, (c) distributing the plurality of pieces of susceptor material throughout the first aerosol-generating substrate and forming an aerosol-generating article in the shape of a particle.

The step (c) may be carried out by a process of granulation.

The method may further comprise a step (d) of coating the aerosol-generating article with a second aerosol-generating substrate. At least one of the steps (c) and (d) of the method may be carried out by a process of granulation. The method may be carried out by a wet granulation process such as high shear granulation, reverse wet granulation, moisture- activated dry granulation, thermal adhesion granulation, melt granulation, freeze granulation, foam granulation or steam granulation. The method may be carried out by means of a fluidized bed granulator, in particular for melt granulation. The method may be carried out by means of a fluidized bed dryer in combination, or in sequence, with the fluidized bed granulator. In particular, the method may be carried out by high shear wet granulation. Accordingly, the method may be carried out by means of a high-shear granulator. Alternatively, the method may be carried out by single-pot granulation. Single-pot granulation may combine the mixing, high- shear wet granulation and drying all in one process bowl. Alternatively, the method may be carried out by a dry granulation process. Dry granulation process may comprise pneumatic dry granulation (PDG).

The method may further comprise a step of applying an external coating. The step of applying the external coating may be carried out by the process of fluidized bed coating and drying.

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

Example Ex1 : An aerosol-generating article for an aerosol-generating device, wherein the aerosol-generating article is in the shape of a particle, and the aerosol-generating article comprises a first aerosol-generating substrate, and a plurality of pieces of susceptor material, wherein the plurality of pieces of susceptor material are distributed throughout the first aerosolgenerating substrate.

Example Ex2: Aerosol-generating article according to Ex1 having a longest dimension being less than twice the shortest dimension of the aerosol-generating article.

Example Ex3: Aerosol-generating article, wherein the aerosol-generating article has a longest dimension being less than twice the shortest dimension of the aerosol-generating article, and wherein the longest dimension of the article is greater than 7 millimeters, and in particular less than 21 millimeters.

Example Ex4: Aerosol-generating article according to any of Ex1 to Ex3, wherein the aerosol-generating article is formed by a granulation process.

Example Ex5: Aerosol-generating article according to any of Ex1 to Ex4, wherein the aerosol-generating article has a convex shape, in particular a spherical shape or an ellipsoid shape.

Example Ex6: Aerosol-generating article according to any of Ex1 to Ex5, wherein the plurality of pieces of susceptor material are susceptor granules, susceptor beads, susceptor flakes, susceptor fibers, susceptor rod or a combination thereof. Example Ex7: Aerosol-generating article according to any of Ex1 to Ex6, wherein the susceptor material is one of paramagnetic, ferromagnetic or ferromagnetic material.

Example Ex8: Aerosol-generating article according to any of Ex1 to Ex7, wherein a size of one piece of susceptor material is between 0.1 millimeters and 2.5 millimeters, in particular between 0.25 millimeters and 1.85 millimeters, more in particular between 0.45 millimeters and 1.55 millimeters.

Example Ex9: Aerosol-generating article according to any of Ex1 to Ex8, wherein the first aerosol-generating substrate comprises 10 to 40 percent per weight of susceptor material.

Example Ex10: Aerosol-generating article according to any of Ex1 to Ex9, wherein the plurality of pieces of susceptor material are evenly distributed in the first aerosol-generating substrate.

Example Ex11 : Aerosol-generating article according to any of Ex1 to Ex10, wherein the first aerosol-generating substrate comprises a first compound comprising at least one of an aerosol former, a blend of tobacco leaf, cellulose fibers, tobacco fibers and a binder.

Example Ex12: Aerosol-generating article according to Ex11 , wherein the first aerosolgenerating substrate comprise at least 3 % per weight, in particular at least 5 % per weight, more in particular at least 10 % per weight, of aerosol former with respect to the weight of the aerosol-generating substrate.

Example Ex13: Aerosol-generating article according to Ex11 or Ex12, wherein the first aerosol-generating substrate further comprises a humectant.

Example Ex14: Aerosol-generating article according to any of Ex1 to Ex13, wherein the first aerosol-generating substrate comprises at least a flavor substance.

Example Ex15: Aerosol-generating article according to Ex14, wherein the flavor substance comprises at least one of an organic botanical glycerite, an organic botanical extract and a botanical essential oil.

Example Ex16: Aerosol-generating article according to any of Ex1 to Ex15, further comprising a second aerosol-generating substrate, wherein the first aerosol-generating substrate is coated with the second aerosol-generating substrate.

Example Ex17: Aerosol-generating article according to Ex16, wherein the second aerosol-generating substrate have a thickness comprised between 0.5 millimeters and 5 millimeters, in particular between 1 millimeter and 4 millimeters.

Example Ex18: Aerosol-generating article according to Ex16 or Ex17, wherein the aerosol-generating article is characterized by an absence of susceptor material in the second aerosol-generating substrate. Example Ex19: Aerosol-generating article according to any of Ex16 to Ex18, wherein an intermediate layer is applied between the first aerosol-generating substrate and the second aerosol-generating substrate.

Example Ex20: Aerosol-generating article according to any of Ex16 to Ex19, wherein the aerosol-generating article further comprises at least an additional aerosol-generating substrate, and the second aerosol-generating substrate is coated with the at least one additional aerosol-generating substrate.

Example Ex21 : Aerosol-generating article according to any of Ex16 to Ex20, wherein the plurality of aerosol-generating substrates differs in at least one of composition, porosity, coating thickness or shape of coating surface.

Example Ex22: Aerosol-generating article according to any of Ex16 to Ex21 , wherein the porosity of the second aerosol-generating substrate is greater than the porosity of the first aerosol-generating substrate.

Example Ex23: Aerosol-generating article according to Ex22, wherein the respective value of the porosity of the first aerosol-generating substrate and the second aerosolgenerating substrate is defined by the ratio of the pore volume of a defined volume of material with respect its total volume.

Example Ex24: Aerosol-generating article according to Ex22 or Ex23, wherein the porosity of the second aerosol-generating substrate is at least 1 .5 times the porosity of the first aerosol-generating substrate.

Example Ex25: Aerosol-generating article according to any of Ex22 to Ex24, wherein the porosity of the second aerosol-generating substrate is comprised between 30 to 80 percent, in particular between 40 to 70 percent, more in particular between 45 to 55 percent.

Example Ex26: Aerosol-generating article according to any of Ex16 to Ex25, wherein the composition of the first aerosol-generating substrate is different from the composition of the second aerosol-generating substrate.

Example Ex27: Aerosol-generating article according to Ex26, wherein the first aerosolgenerating substrate comprises a greater amount of aerosol former than the second aerosolgenerating substrate.

Example Ex28: Aerosol-generating article according to Ex26 or Ex27, wherein the second aerosol-generating substrate comprises a greater amount of tobacco fibers than the first aerosol-generating substrate.

Example Ex29: Aerosol-generating article according to any of Ex26 to Ex28, wherein the shape of the external surface of the first aerosol-generating substrate differs from the shape of the external surface of the second aerosol-generating substrate. Example Ex30: Aerosol-generating article according to any of Ex1 to Ex29, wherein the longest dimension of the aerosol-generating article is greater than 7 millimeters, and in particular less than 21 millimeters.

Example Ex31 : Aerosol-generating article according to Ex30, wherein the longest dimension of the aerosol-generating article is comprised between 7 and 16 millimeters.

Example Ex32: Aerosol-generating article according to Ex30 or Ex31 , wherein a longest dimension of the first aerosol-generating substrate is comprised between 3.5 millimeters and 17 millimeters, in particular between 4 millimeters and 14 millimeters.

Example Ex33: Aerosol-generating article according to any of Ex1 to Ex32, further comprising an external coating.

Example Ex34: Aerosol-generating article according to Ex33, wherein the external coating is a porous coating.

Example Ex35: Aerosol-generating article according to Ex16 and Ex34, wherein the porosity of the second aerosol-generating substrate is greater than the porosity of the external coating.

Example Ex36: Aerosol-generating article according to Ex16 and Ex33, wherein the external coating covers only partially the first aerosol-generating substrate or the second aerosol-generating substrate.

Example Ex37: Aerosol-generating article according to one of Ex33 to Ex36, wherein the external coating is applied according to a predetermined pattern on the first aerosol-generating substrate or the second aerosol-generating.

Example Ex38: Aerosol-generating article according to one of Ex33 to Ex36, wherein the external coating covers the first aerosol-generating substrate or the second aerosol-generating entirely.

Example Ex39: Aerosol-generating article according to one of Ex33 to Ex38, wherein the material of the external coating has an alginate-based formulation.

Example Ex40: Aerosol-generating article according to Ex39, wherein the material of the external coating comprises at least one of: Alginate, Alginate-maltodextrin, Alginate-galbanum gum, Starch-alginate, crosslinking with CaCI2, CaCI2-CMC, Calcium gluconate, calcium lactate and tapioca starch.

Example Ex41 : Aerosol-generating article according to Ex39 or Ex40, wherein the material of the external coating further comprises an antimicrobial substance.

Example Ex42: Aerosol-generating article according to any of Ex39 or Ex41 , wherein the material of the external coating has anti-adhesion properties. Example Ex43: Aerosol-generating article according to any of Ex39 or Ex42, wherein the external coating is biodegradable.

Example Ex44: Aerosol-generating article according to any of Ex39 or Ex43, wherein the external coating exclusively comprises a bio-based material.

Example Ex45: Aerosol-generating article according to any of Ex39 or Ex43, wherein the external coating exclusively comprises a natural material.

Example Ex46: Aerosol-generating article according to any of Ex39 or Ex43, wherein the external coating exclusively comprises a combination of natural material and bio-based material.

Example Ex47: Aerosol-generating article according to any of Ex39 or Ex46, wherein the external coating comprises vanillin, thyme oil, lemongrass extract, carvacrol, methyl cinnamate, nisin, acetic acid, lactic acid, potassium sorbate, Ziziphora persica essential oil and extract(s), sodium lactate, sodium diacetate, pomegranate peel extract, lemongrass extract(s).

Example Ex48: Aerosol-generating article according to one of Ex33 to Ex38, wherein the external coating is made of vanillin, thyme oil, lemongrass extract, carvacrol, methyl cinnamate, nisin, acetic acid, lactic acid, potassium sorbate, Ziziphora persica essential oil and extract(s), sodium lactate, sodium diacetate, pomegranate peel extract, lemongrass extract(s).

Example Ex49: A method of manufacturing an aerosol-generating article, comprising the steps of: (a) providing a first aerosol-generating substrate, (b) providing a plurality of pieces of susceptor material, (c) distributing the plurality of pieces of susceptor material throughout the first aerosol-generating substrate and forming an aerosol-generating article in the shape of a particle.

Example Ex50: Method according to Ex49, further comprising a step (d) of coating the aerosol-generating article with a second aerosol-generating substrate.

Example Ex51 : Method according to Ex49 or Ex50, wherein at least one of the steps (c) and (d) is carried out by a process of granulation.

Example Ex52: Method according to any of Ex49 to Ex51 , wherein the granulation process comprises the process of fluidized granulation and drying.

Example Ex53: Method according to any of Ex49 to Ex51 , wherein the granulation process comprises the process of high shear granulation.

Example Ex54: Method according to any of Ex49 to Ex51 , wherein the granulation process comprises the process of single-pot granulation. Example Ex55: Method according to any of Ex49 to Ex51 , wherein the granulation process is carried out by a compact granulation system.

Example Ex56: Method according to any of Ex49 to Ex55, further comprising a step of applying an external coating.

Examples will now be further described with reference to the figures.

Fig. 1 shows a schematic representation of an aerosol-generating article according to a first embodiment, wherein the aerosol-generating article is cut in half and slightly opened to see inside.

Fig. 2 shows a schematic representation of half of an aerosol-generating article according to a second embodiment.

Fig. 3 shows a schematic diagram illustrating a method of manufacturing the aerosolgenerating article according to the first embodiment.

Fig. 4 shows a schematic diagram illustrating a method of manufacturing the aerosolgenerating article according to the second embodiment.

Fig. 1 shows an aerosol-generating article 10 according to a first embodiment. The aerosol-generating article 10 is in the shape of a particle, in particular a spherical particle. In the schematic view of Fig. 1 , the aerosol-generating article 10 is cut in two half portions 12, 14 so as to make the inside of the aerosol-generating article 10 visible. As can be seen from the half portions 12, 14 in Fig. 1 , the aerosol-generating article 10 comprises a first aerosolgenerating substrate 16 and a plurality of pieces of susceptor material 18. The first aerosolgenerating substrate 16 may comprise 10 to 40 weight percent, in particular 15 to 30 weight percent, of susceptor material 18. The plurality of pieces of susceptor material 18 are distributed throughout the first aerosol-generating substrate 16. The plurality of pieces of susceptor material 18 are thus spaced from one another by the first aerosol-generating substrate 16. The plurality of pieces of susceptor material 18 are conductive pieces that have the ability to convert electromagnetic energy and convert it to heat. When located in an alternating electromagnetic field, eddy currents are induced and hysteresis losses occur in the susceptor material 18 causing heating of the susceptor material 18. As in the aerosolgenerating article 10 the plurality of pieces of susceptor material 18 is located in direct physical contact, and thus, in thermal contact, with the first aerosol-generating substrate 16, the first aerosol-generating substrate 16 can be heated by the susceptor pieces 18 such that an aerosol can be formed.

The greatest dimension of the aerosol-generating article 10 according to the first embodiment corresponds to the diameter 20 of the spherical particle. The diameter 20 is greater than 7 millimeters, and in particular less than 21 millimeters. The aerosol-generating article 10 may further comprise an external coating 22. As shown in Fig. 1 , the external coating 22 defines the outmost layer of the aerosol-generating article 10. The external coating 22 may provide a protection layer to the aerosol-generating article 10, in particular for limiting the permeation of oxygen or water vapour into the aerosol-generating article 10, which may help to extend the shelf life of the aerosol-generating article 10. Alternatively or in addition, the external coating 22 may help to protect the structural integrity of the aerosol-generating article 10, which is in the shape of a particle. The external coating 22 may be colored for indicating a property of the aerosol-generating article 10, such as the flavour or the content of nicotine. Alternatively or in addition, the external coating 22 may have anti-adhesive properties, in particular for preventing stickiness between a plurality of aerosolgenerating articles 10 when they are stored together.

Fig. 2 shows one half 28 of an aerosol-generating article 30 according to a second embodiment. Like the aerosol-generating article 10 according to the first embodiment, the aerosol-generating article 30 is in the shape of a particle, in particular a spherical particle. The aerosol-generating article 30 comprises a core 32. The core 32 consists of the first aerosolgenerating substrate 16 and the plurality of pieces of susceptor material 18 distributed throughout the first aerosol-generating substrate 16, as described in relation to the first embodiment. In the second embodiment, the core 32 is coated with a second aerosolgenerating substrate 34. In contrast to the first aerosol-generating substrate 16, the second aerosol-generating substrate 34 does not comprise susceptor material. The first aerosolgenerating substrate 16 and the second aerosol-generating substrate 34 may differ in at least one of composition, porosity, moisture content or coating thickness. The porosity of the second aerosol-generating substrate 34 may be at least 1 .5 times the porosity of the first aerosolgenerating substrate 16.

The greatest dimension of the aerosol-generating article 30 corresponds to the diameter 20 of the spherical particle. The diameter 20 is greater than 7 millimeters, and in particular less than 21 millimeters. The greatest dimension 36 of the core 32 may be comprised between 3.5 millimeters and 17 millimeters, in particular between 4 millimeters and 14 millimeters. The greatest dimension 38 of the thickness of the second aerosol-generating substrate 34 may be comprised between 0.5 millimeters and 5 millimeters, in particular between 1 millimeter and 4 millimeters.

Like in the first embodiment, the aerosol-generating article 30 may further comprise an external coating 22. In the second embodiment, the external coating 22 covers an outermost surface of the second aerosol-generating substrate 34. The external coating 22 may be porous. The porosity of the external coating 22 may allow an airflow of aerosol, represented by the arrow 40 in Fig. 2, which is generated by the heating of the first aerosol-generating substrate 16 by means of the pieces of susceptor material 18, to first pass through the second aerosolgeneration substrate 34, and then to be released to the outside of the particle 30 by passing through pores (not illustrated in Fig. 2) of the porous external coating 22.

The overlaying of aerosol-generating substrates may help further defining the airflow rate, the airflow distribution, or both, of the aerosol 40 generated in the core 32 of the aerosolgenerating article 30. Alternatively, or in combination, the overlaying of aerosol-generating substrates 16, 34 may help further defining the flavor of the aerosol 40 generated by the aerosol-generating article 30. For further enhancing these properties, in another embodiment (not illustrated), the aerosol-generating article may comprise at least one further aerosolgenerating substrate in addition to the first aerosol-generating substrate 16 and the second aerosol-generation substrate 34.

Fig. 3 shows a schematic diagram illustrating a method 100 of manufacturing the aerosol-generating article 10 according to the first embodiment. The schematic diagram of Fig. 3 illustrates the method 100 that comprises a step 102 of providing a first aerosol substrate 16, a step 104 of providing a plurality of pieces of susceptor material 18 and a step 106 of distributing the plurality of pieces of susceptor material 18 throughout the first aerosolgenerating substrate 16 and forming the aerosol-generating article 10 in the shape of a particle.

The method 100 comprises a step 102 of providing a first aerosol substrate 16. The first aerosol substrate 16 comprises at least one of an aerosol former, a blend of tobacco leaf, cellulose fibers, tobacco fibers and a binder. The method 100 comprises a step 104 of providing a plurality of pieces of susceptor material 18. The plurality of pieces of susceptor material 18 may be susceptor granules, susceptor beads, susceptor grits, susceptor flakes, susceptor fibers, susceptor rod or a combination thereof. The method 100 further comprises a step 106 of distributing the plurality of pieces of susceptor material 18 throughout the first aerosol-generating substrate 16 and forming the aerosol-generating article 10 in the shape of a particle. The step 106 of the method 100 may be carried out by a granulation process, in particular wet granulation process. Granulation process allows improving the homogeneity of the distribution of the plurality of pieces of susceptor material 18 throughout the first aerosolgenerating substrate 16. Optionally, the method 100 comprises a further step of applying an external coating, in particular by a film coating process or a fluidized coating process.

Fig. 4 shows a schematic diagram illustrating a method 300 of manufacturing the aerosol-generating article 30 according to the second embodiment. The schematic diagram of Fig. 4 illustrates the method 300 that comprises a step 302 of providing a first aerosol substrate 16, a step 304 of providing a plurality of pieces of susceptor material 18, a step 306 of distributing the plurality of pieces of susceptor material 18 throughout the first aerosolgenerating substrate 16 and forming a core 32, a step 308 of coating the core 32 with a second aerosol-generating substrate 34 and forming an aerosol-generating article 30 in the shape of a particle.

As the method 100 of the first embodiment, the method 300 also comprises a step 302 of providing the first aerosol substrate 16 and a step 304 of providing a plurality of pieces of susceptor material 18. The method 300 further comprises a step 306 of distributing the plurality of pieces of susceptor material 18 throughout the first aerosol-generating substrate 16 so as to form a core 32. Then, the method 300 comprises a step 308 of coating the core 32 with a second aerosol-generating substrate 34 and forming an aerosol-generating article 30 in the shape of a particle. The step 306 and the step 308 of the method 300 may be carried out by a granulation process. The step 306 may be carried out by a wet granulation process. The step 308 may be carried out by a dry granulation process. Optionally, the method 300 comprises a further step of applying an external coating, in particular by a film coating process or a fluidized coating process.

For the purpose of the present description and of the appended claims, except where otherwise indicated, all numbers expressing amounts, quantities, percentages, and so forth, are to be understood as being modified in all instances by the term "about". Also, all ranges include the maximum and minimum points disclosed and include any intermediate ranges therein, which may or may not be specifically enumerated herein. In this context, therefore, a number A is understood as A ± 5% of A. Within this context, a number A may be considered to include numerical values that are within general standard error for the measurement of the property that the number A modifies. The number A, in some instances as used in the appended claims, may deviate by the percentages enumerated above provided that the amount by which A deviates does not materially affect the basic and novel characteristic(s) of the claimed invention. Also, all ranges include the maximum and minimum points disclosed and include any intermediate ranges therein, which may or may not be specifically enumerated herein.

Claims

1 . An aerosol-generating article for an aerosol-generating device, wherein the aerosol-generating article is in the shape of a particle, and the aerosol-generating article comprises: a first aerosol-generating substrate, and a plurality of pieces of susceptor material, wherein the plurality of pieces of susceptor material are distributed throughout the first aerosolgenerating substrate.

2. The aerosol-generating article according to claim 1 , wherein the first aerosol-generating substrate comprises 10 to 40 percent per weight of susceptor material.

3. The aerosol-generating article according to claim 1 or 2, wherein the first aerosol-generating substrate comprises at least a flavor substance.

4. The aerosol-generating article according to one of the preceding claims, further comprising a second aerosol-generating substrate, wherein the first aerosol-generating substrate is coated with the second aerosol-generating substrate.

5. The aerosol-generating article according to claim 4, wherein the porosity of the second aerosol-generating substrate is greater than the porosity of the first aerosol-generating substrate.

6. The aerosol-generating article according to claim 5, wherein the porosity of the second aerosol-generating substrate is at least 1.5 times the porosity of the first aerosol-generating substrate.

7. The aerosol-generating article according to claim 5 or 6, wherein the composition of the first aerosol-generating substrate is different from the composition of the second aerosolgenerating substrate.

8. The aerosol-generating article according to one of the preceding claims, wherein the longest dimension of the aerosol-generating article is greater than 7 millimeters, and in particular less than 21 millimeters.

9. The aerosol-generating article according to one of the preceding claims, further comprising an external coating.

10. The aerosol-generating article according to claim 9, wherein the external coating is a porous coating.

11. The aerosol-generating article according to claim 9 or 10, wherein the material of the external coating has an alginate-based formulation.

12. A method of manufacturing an aerosol-generating article, comprising the steps of:

(a) providing a first aerosol-generating substrate,

(b) providing a plurality of pieces of susceptor material,

(c) distributing the plurality of pieces of susceptor material throughout the first aerosolgenerating substrate and forming an aerosol-generating article in the shape of a particle.

13. The method of claim 12, further comprising a step (d) of coating the aerosol-generating article with a second aerosol-generating substrate.

14. The method according to claim 12 or 13, wherein at least one of the steps (c) and (d) is carried out by a process of granulation.

15. The method according to one of claims 12 to 14, further comprising a step of applying an external coating.