Novel aerosol-generating substrate comprising a plurality of connected aerosol-generating beads

Abstract

The present invention relates to an aerosol-generating substrate (1000) for use in an aerosol-generating article (10) or system. The aerosol-generating substrate comprises two or more aerosol-generating beads (1010) and a support element (1020) linking the two or more aerosol-generating beads. Each aerosol-generating bead comprises: a cellulose-containing powder; an aerosol former; and optionally a binder. For example, the support element linking the two or more aerosol-generating beads may comprise at least a supporting thread extending through the two or more aerosol-generating beads.

Description

[0001] P / 90765.W001

[0002] NOVEL AEROSOL-GENERATING SUBSTRATE COMPRISING A PLURALITY OF CONNECTED AEROSOL-GENERATING BEADS

[0003] The present disclosure relates to an aerosol-generating substrate for an aerosolgenerating article. Further, the present disclosure relates to an aerosol-generating article comprising the aerosol-generating substrate. The aerosol-generating article may also form part of an aerosol-generating system, wherein in the aerosol-generating article is paired with an aerosol-generating device configured to heat the aerosol-generating substrate. Alternatively, the aerosol-generating substrate may be directly paired with the aerosol-generating device.

[0004] Aerosol generating substrates for an aerosol-generating article where the aerosolgenerating substrate, such as a tobacco containing substrate, is heated rather than combusted are known in the art. Typically, in such aerosol generating articles an aerosol is generated by the transfer of heat from a heat source to an aerosol-generating substrate.

[0005] Electrically operated aerosol-generating devices, for example handheld aerosolgenerating devices, may be used with such aerosol generating articles. Such electrically operated aerosol-generating devices may comprise a heating element configured to heat an aerosolgenerating substrate. This releases volatile compounds from the aerosol-generating substrate which are entrained in air drawn through the aerosol generating article. As the released compounds cool, they condense or nucleate to form an aerosol.

[0006] Several examples of aerosol-generating devices for consuming aerosol-generating articles have been disclosed in the art. Such devices include, for example, electrically heated aerosol-generating devices in which an aerosol is generated by the transfer of heat from one or more electrical heater elements of the aerosol-generating device to the aerosol-generating element of an aerosol-generating article. To this purpose, the aerosol-generating article may be partially received within a heating cavity of the aerosol-generating device, such that an upstream end of the aerosol-generating article is inserted into the cavity whereas a downstream end of the aerosol-generating article projects out of the cavity.

[0007] For example, heating of the aerosol-generating substrate has been accomplished using external heating, such as by way of a tubular heater element that at least partially defines a heating cavity into which the aerosol-generating article is inserted. Heating of an aerosolgenerating substrate by providing an inductive heating element in the form of a susceptor element thermally coupled with the aerosol-generating substrate and capable of being heated when penetrated by a varying magnetic field is also known.

[0008] A number of different aerosol-generating substrates for heated aerosol-generating articles have been disclosed. In some examples, the aerosol-generating article comprises a solid aerosolgenerating substrate, such as a cylindrical rod of a plant material, for example comprising a homogenised tobacco material or tobacco cut filler or a non-tobacco homogenised plant material. P / 90765.W001

[0009] Also known is a solid aerosol-generating substrate comprising a gathered sheet of non-tobacco material loaded with nicotine (for example, in the form of a nicotine salt) and an aerosol former.

[0010] However, such cylindrical rods of plant material have been found to not always provide optimal aerosol generation when heated, rather than combusted. A rod of cut filler will typically have a relatively high density and a relatively low porosity, due to the way in which the tobacco material is compacted during manufacture. This can present challenges for the uniform heating of the tobacco material and, in fact, research has shown that a significant proportion of the cylindrical rod may not be sufficiently heated to form an aerosol during use. This proportion of the rod is therefore effectively wasted. Furthermore, the fixed size and shape of the cylindrical rod of tobacco material provides little flexibility for the aerosol-generating substrate to be adapted for use in new, more efficient designs of aerosol-generating article and aerosol-generating device.

[0011] It would be desirable to provide a novel substrate for a heated aerosol-generating article, which can achieve a more efficient generation of aerosol and which provides an improved experience for the consumer. It would be particularly desirable to provide such a novel substrate which offers more flexibility to be arranged in different shapes and forms, such that it can be adapted for use with a wider variety of aerosol-generating articles and devices.

[0012] According to the present disclosure, there is provided an aerosol-generating substrate for use in an aerosol-generating article or system. The aerosol-generating substrate may comprise two or more aerosol-generating beads. The aerosol-generating substrate may comprise a support element linking the two or more aerosol-generating beads. Each aerosol-generating bead may comprise a cellulose-containing powder. Each aerosol-generating bead may comprise an aerosol former. Each aerosol-generating bead may comprise a binder.

[0013] According to the present invention there is provided an aerosol-generating substrate for use in an aerosol-generating article or system, the aerosol-generating substrate comprising: two or more aerosol-generating beads; and a support element linking the two or more aerosolgenerating beads, wherein each aerosol-generating bead comprises: a cellulose-containing powder; an aerosol former; and optionally a binder.

[0014] According to the present invention there is also provided an aerosol-generating article comprising an aerosol-generating substrate according to the invention, as defined above.

[0015] According to the present disclosure there is also provided a method of producing an aerosol-generating substrate according to the present invention, as defined above, the method comprising the steps of: mixing cellulose-containing powder, an aerosol former and optionally a binder to form a dough; forming a plurality of aerosol-generating beads from the dough; providing a support element; linking two or more of the formed aerosol-generating beads to provide the aerosol-generating substrate.

[0016] As used herein, the term “aerosol-generating substrate” refers to a substrate capable of releasing upon heating volatile compounds, which can condense to form an aerosol. P / 90765.W001

[0017] As used herein, the term “aerosol” denotes a dispersion of solid particles, or liquid droplets, or a combination of solid particles and liquid droplets, in a gas. The aerosol may be visible or invisible. The aerosol may include vapours of substances that are ordinarily liquid or solid at room temperature as well as solid particles, or liquid droplets, or a combination of solid particles and liquid droplets.

[0018] As used herein, the term “aerosol-generating article” refers to an aerosol-generating article for producing an aerosol comprising an aerosol-generating substrate that is intended to be heated rather than combusted in order to release volatile compounds that can form an aerosol.

[0019] As used herein, the term “aerosol-generating device” denotes a device that interacts with an aerosol-generating substrate to generate an aerosol. In some examples, an aerosolgenerating device heats the aerosol-generating substrate to facilitate release of volatile compounds from the aerosol-generating substrate.

[0020] As used herein, the term “aerosol-generating system” refers to the combination of an aerosol-generating device and an aerosol-generating substrate or article.

[0021] As used herein, a content of a component of the aerosol-generating substrate on a “dry weight basis” refers to the weight of a particular non-water component relative to the sum of the weights of all non-water components in a mixture, expressed as a percentage. A mass ratio of two or more components of an aerosol-generating substrate on a “dry weight basis” refers to a ratio of the weight of a particular non-water component relative to another particular non-water component.

[0022] As used herein, the term “bead” refers to a discrete, solid particle formed of an aerosolgenerating substrate as defined above and which comprises a body which may have any suitable shape. For example, the body may have an axially symmetric shape, such as for example cylindrical, spherical, hemispherical, cup-shaped, ring-shaped and disc-shaped. In the context of the present disclosure the term “bead” is used essentially as a synonym of the term “granule”, and as such it is not intended to imply that the body of the bead has a specific shape.

[0023] Beads of aerosol-generating substrate according to the present disclosure may be formed by any suitable method. For example, the cellulose-containing powder, aerosol former, and optional binder can be combined to form a dough, which is subsequently extruded to form an extrudate strand. The extrudate strand may, for example, be cut into short lengths to form beads having a substantially cylindrical body. As an alternative, the extrudate strand may be cut into short lengths, which are then rounded, for example by being placed on a rotating plate within a cylinder, to form beads having a substantially spherical body (spheronisation).

[0024] The present invention provides a novel and improved form of aerosol-generating substrate for an aerosol-generating article or aerosol-generating system.

[0025] The body of each bead is formed of a material comprising a cellulose-containing powder, an aerosol former, an optionally a binder. The combination of cellulose-containing powder with aerosol former, with the optional addition of a binder, has been found to provide an aerosolgenerating substrate that can advantageously be formed stably into beads, which retain their shape and can be used directly in an aerosol-generating article. In particular, the consistency and stability of the formulation used to form the beads enables the beads to be used without the need for an additional coating layer. This simplifies the production process and additionally optimises the release of aerosol from the beads or granules upon heating.

[0026] Further, two or more of the aerosol-generating beads are linked to each other by a support element. As will be described in more detail below, the support element may for example comprise a supporting thread that extends through two or more aerosol-generating beads. In some example, the support element may comprise two or more supporting threads, each supporting thread extending through a respective group of two or more aerosol-generating beads. Linking and supporting the aerosol-generating beads enables makes it possible for a plurality of aerosol-generating beads to be provided in predefined regular arrangements, which may advantageously facilitate incorporating a given number of beads within a predefined volume. Thus, an aerosol-generating substrate in line with the present disclosure may advantageously be adapted for use in aerosol-generating articles and systems having different geometries. Additionally, the size and number of the aerosol-generating beads can be readily adapted to suit the space into which the aerosol-generating substrate is incorporated.

[0027] The aerosol-generating substrate therefore offers improved flexibility and versatility. The aerosol-generating substrate finds particular application in planar or flat aerosol-generating articles, which offer more efficient heating and generation of aerosol due to the flat structure of the aerosol-generating substrate. However, as will become apparent from the following description of a number of different embodiments, the aerosol-generating substrates of the present disclosure can generally be adapted to fit into spaces of different shapes and sizes, and especially in narrow cavities.

[0028] The provision of an aerosol-generating substrate in the form of a plurality of linked beads also advantageously provides a substrate with a desirable surface to volume ratio, which optimises release of aerosol from the substrate upon heating.

[0029] Furthermore, aerosol-generating substrates of the present invention comprising tobacco plant powder as the cellulose-containing powder have surprisingly been found to provide a significant improvement in the consistency of the nicotine to aerosol former ratio in the aerosol generated upon heating compared to known substrates comprising a rod of tobacco material, as described above. In particular, the aerosol-generating substrate of the present invention can provide a more consistent nicotine to aerosol former ratio in the aerosol per puff across the full duration of heating. This provides the consumer with an optimised sensory experience.

[0030] The aerosol-generating substrate according to the invention can be advantageously produced using known apparatus and methods, with relatively minor modifications. The aerosol- P / 90765.W001 generating substrate can additionally be produced using relatively low amounts of water compared to processes for making other substrates such as homogenised tobacco material, which reduces the time and energy requirements, as well as reducing the environmental impact.

[0031] As described briefly above, the aerosol-generating substrate comprises two or more aerosol-generating beads.

[0032] An aerosol-generating bead of an aerosol-generating substrate in accordance with the present disclosure comprises a body that may have any suitable shape. For example, the body may have an axially symmetric shape, such as for example cylindrical, spherical, hemispherical, cup-shaped, disc-shaped.

[0033] In some embodiments, an aerosol-generating bead comprises a body and a channel extending through the body, the body being substantially disc-shaped or ring-shaped.

[0034] With reference to the body of a bead of an aerosol-generating substrate in accordance with the present disclosure, the term “disc-shaped” is used to denote a bead comprising a body that has substantially the shape of a right circular cylinder, wherein a height of the cylinder is smaller than a radius of the cylinder, and wherein the channel extends through the body from one base of the cylinder to the other base of the cylinder. The term “ring-shaped” is used to denote a bead comprising a body that has substantially the shape of a solid torus, that is, a solid formed by rotating a disk around an axis. In embodiments wherein the body of the bead has an axially symmetric shape, the channel preferably extends through the body along the axis of symmetry of the body.

[0035] An average bead size of the two or more aerosol-generating beads is at least 0.1 millimetres. As used herein, the term “bead size” refers to the largest cross sectional dimension of the individual aerosol-generating beads.

[0036] For example, with reference to a bead having a spherical body, the term “bead size” generally denotes a diameter of the spherical body. When describing a bead having a cylindrical body, the term “bead size” generally refers to the diameter or the height of the cylinder, whichever is larger. With reference to a disc-shaped bead or a ring-shaped bead, the term “bead size” denotes the outer diameter of the bead.

[0037] The term "average bead size” is used herein to denote the arithmetic mean bead size for the two or more aerosol-generating beads. The bead size distribution for a sample of aerosolgenerating substrate may be determined using a known sieve test. Beads having the desired size may be obtained by passing a population of beads through sieve of suitable mesh sizes.

[0038] For example, a sieve shaker may be used to help promote particle movement through a stack of sieves of different mesh sizes, so as to facilitate accurate particle separation. As the particles present within a sample being tested separate, they are retained on the various sieves in the stack depending on their size, providing insight into the average particle size of the sample. ASTM C136 / C136M - 14 describes a standard test method for the determination of the particle P / 90765.W001 size distribution of fine and coarse aggregates by sieving, wherein use of a mechanical sieve shaker can be incorporated.

[0039] An average bead size of the two or more aerosol-generating beads may be at least 0.25 millimetres. For example, an average bead size (or an average equivalent diameter) of the two or more aerosol-generating beads may be at least 0.5 millimetres or at least 0.75 millimetres. Preferably, an average bead size of the two or more aerosol-generating beads is at least 1 millimetre.

[0040] More preferably, an average bead (or an average equivalent diameter) size of the two or more aerosol-generating beads is at least 1.5 millimetres. Even more preferably, an average bead size of the two or more aerosol-generating beads is at least 2 millimetres.

[0041] In an aerosol-generating substrate according to the present invention, an average bead size (or an average equivalent diameter) of the two or more aerosol-generating beads may be less than or equal to 12 millimetres.

[0042] For example, an average bead size (or an average equivalent diameter) of the two or more aerosol-generating beads may be less than or equal to 10 millimetres, less than or equal to 8 millimetres, less than or equal to 6 millimetres.

[0043] Preferably, an average bead size (or an average equivalent diameter) of the two or more aerosol-generating beads may be less than or equal to 5.5 millimetres. More preferably, an average bead size of the two or more aerosol-generating beads may be less than or equal to 5 millimetres. Even more preferably, an average bead size of the two or more aerosol-generating beads may be less than or equal to 4.5 millimetres. In particularly preferred embodiments, an average bead size of the two or more aerosol-generating beads may be less than or equal to 3 millimetres.

[0044] For example, an average bead size (or an average equivalent diameter) of the two or more aerosol-generating beads may be from 0.1 millimetres to 12 millimetres, from 0.1 millimetres to 10 millimetres, from 0.1 millimetres to 8 millimetres, from 0.1 millimetres to 6 millimetres, from 0.1 millimetres to 5.5 millimetres, from 0.1 millimetres to 5 millimetres, from 0.1 millimetres to 4.5 millimetres, or from 0.1 millimetres to 3 millimetres.

[0045] An average bead size (or an average equivalent diameter) of the two or more aerosolgenerating beads may for example be from 0.25 millimetres to 12 millimetres, from 0.25 millimetres to 10 millimetres, from 0.25 millimetres to 8 millimetres, from 0.25 millimetres to 6 millimetres, from 0.25 millimetres to 5.5 millimetres, from 0.25 millimetres to 5 millimetres, from 0.25 millimetres to 4.5 millimetres, or from 0.25 millimetres to 3 millimetres.

[0046] An average bead size (or an average equivalent diameter) of the two or more aerosolgenerating beads may for example be from 0.5 millimetres to 12 millimetres, from 0.5 millimetres to 10 millimetres, from 0.5 millimetres to 8 millimetres, from 0.5 millimetres to 6 millimetres, from P / 90765.W001

[0047] 0.5 millimetres to 5.5 millimetres, from 0.5 millimetres to 5 millimetres, from 0.5 millimetres to 4.5 millimetres, or from 0.5 millimetres to 3 millimetres.

[0048] An average bead size (or an average equivalent diameter) of the two or more aerosolgenerating beads may for example be from 0.75 millimetres to 12 millimetres, from 0.75 millimetres to 10 millimetres, from 0.75 millimetres to 8 millimetres, from 0.75 millimetres to 6 millimetres, from 0.75 millimetres to 5.5 millimetres, from 0.75 millimetres to 5 millimetres, from 0.75 millimetres to 4.5 millimetres, or from 0.75 millimetres to 3 millimetres.

[0049] In some examples, an average bead size (or an average equivalent diameter) of the two or more aerosol-generating beads is from 1 millimetre to 6 millimetres, preferably from 1 millimetre to 5.5 millimetres, more preferably from 1 millimetre to 5 millimetres, even more preferably from 1 millimetre to 4.5 millimetres. In particularly preferred examples, an average bead size (or an average equivalent diameter) of the two or more aerosol-generating beads is from 1 millimetre to 3 millimetres.

[0050] In other examples, an average bead size (or an average equivalent diameter) of the two or more aerosol-generating beads is from 1.25 millimetre to 6 millimetres, preferably from 1.25 millimetre to 5.5 millimetres, more preferably from 1.25 millimetre to 5 millimetres, even more preferably from 1.25 millimetre to 4.5 millimetres. In particularly preferred examples, an average bead size (or an average equivalent diameter) of the two or more aerosol-generating beads is from 1.25 millimetres to 3 millimetres.

[0051] In further example, an average bead size (or an average equivalent diameter) of the two or more aerosol-generating beads is from 1.5 millimetre to 6 millimetres, preferably from 1.5 millimetre to 5.5 millimetres, more preferably from 1.5 millimetre to 5 millimetres, even more preferably from 1.5 millimetre to 4.5 millimetres. In particularly preferred examples, an average bead size (or an average equivalent diameter) of the two or more aerosol-generating beads is from 1.5 millimetres to 3 millimetres.

[0052] In yet further examples, an average bead size (or an average equivalent diameter) of the two or more aerosol-generating beads is from 2 millimetre to 6 millimetres, preferably from 2 millimetre to 5.5 millimetres, more preferably from 2 millimetre to 5 millimetres, even more preferably from 2 millimetre to 4.5 millimetres. In particularly preferred examples, an average bead size (or an average equivalent diameter) of the two or more aerosol-generating beads is from 2 millimetres to 3 millimetres.

[0053] Aerosol-generating substrates in accordance with the present disclosure having an average bead size (or an average equivalent diameter) falling within the ranges described above have the advantage that they may easily fit within a cavity of an aerosol-generating article or system in a way that balances the desire to provide a certain aerosol delivery to the consumer - and, therefore, the desire to accommodate a given weight of aerosol-generating substrate within P / 90765.W001 the cavity - with the need to control the bulk density and void fraction, which may generally have an impact on a resistance to draw of the aerosol-generating article.

[0054] The average bead size (or average equivalent diameter) may also generally have an impact on how the bead responds to heat exposure. That is, beads according to the present invention that have substantially the same formulation and different size (or equivalent diameter) may, when heated under substantially the same conditions (for example, heating rate, maximum temperature, etc.) release aerosol species at different rates, for a different period of time, and so forth. Accordingly, adjusting the average bead size (or average equivalent diameter) of an aerosol-generating substrate according to the present invention may be a way of adapting the aerosol-generating substrate to providing different aerosol delivery profiles.

[0055] As described briefly above, in some embodiments, an aerosol-generating bead comprises a body and a channel extending through the body, the body being substantially disc-shaped or ring-shaped.

[0056] In such embodiments, an equivalent internal diameter of the channel may for example be at least 0.3 millimetres. Preferably, an equivalent internal diameter of the channel is at least 0.4 millimetres. More preferably, an equivalent internal diameter of the channel is at least 0.75 millimetres. Even more preferably, an equivalent internal diameter of the channel is at least 1.5 millimetres.

[0057] In such embodiments, an equivalent internal diameter of the channel may for example be up to 7 millimetres. Preferably, an equivalent internal diameter of the channel is less than or equal to 6 millimetres. More preferably, an equivalent internal diameter of the channel is less than or equal to 5 millimetres. Even more preferably, an equivalent internal diameter of the channel is less than or equal to 3 millimetres.

[0058] In such embodiments, a ratio between an equivalent internal diameter of the channel and an equivalent outer diameter of the body may be at least 0.13. Preferably, a ratio between an equivalent internal diameter of the channel and an equivalent outer diameter of the body is at least 0.25. More preferably, a ratio between an equivalent internal diameter of the channel and an equivalent outer diameter of the body is at least 0.35. Even more preferably, a ratio between an equivalent internal diameter of the channel and an equivalent outer diameter of the body is at least 0.5.

[0059] In such embodiments, a ratio between an equivalent internal diameter of the channel and an equivalent outer diameter of the body may be up to 0.98. Preferably, a ratio between an equivalent internal diameter of the channel and an equivalent outer diameter of the body is less than or equal to 0.9. More preferably, a ratio between an equivalent internal diameter of the channel and an equivalent outer diameter of the body is less than or equal to 0.8.

[0060] In the beads of an aerosol-generating substrate according to the present disclosure, a thickness of the body may be at least 0.1 millimetres. P / 90765.W001

[0061] For example, a thickness of the body may be at least 0.25 millimetres or at least 0.5 millimetres.

[0062] In the context of the present disclosure, the term “thickness of the body” is used to denote the distance between opposite ends of the body of a bead having an axially symmetric shape, the distance measured along the direction defined by the axis of symmetry. For example, with reference to a disc-shaped bead , the term “thickness of the body” identifies the distance between opposite bases of the right circular cylinder. With reference to a ring-shaped bead, the term “thickness of the body” identifies the distance between opposite ends of the bead, which is substantially equal to a diameter of the disk the rotation of which forms the solid torus.

[0063] In certain embodiments, a thickness of the body may for example be up to 1 millimetre. A thickness of the body may be less than or equal to 0.8 millimetres, less than or equal to 0.6 millimetres, or less than or equal to 0.5 millimetres.

[0064] In such embodiments, the body may have a thickness from 0.1 millimetres to 1 millimetre, from 0.1 millimetres to 0.8 millimetres, from 0.1 millimetres to 0.6 millimetres, or from 0.1 millimetres to 0.5 millimetres.

[0065] In such embodiments, the body may have a thickness from 0.25 millimetres to 1 millimetre, from 0.25 millimetres to 0.8 millimetres, from 0.25 millimetres to 0.6 millimetres, or from 0.25 millimetres to 0.5 millimetres.

[0066] In such embodiments, the body may have a thickness from 0.5 millimetres to 1 millimetre, from 0.5 millimetres to 0.8 millimetres, or from 0.5 millimetres to 0.6 millimetres.

[0067] In other embodiments, a thickness of the body may for example be up to 6 millimetres. A thickness of the body may be less than or equal to 5 millimetres, preferably less than 4 millimetres, even more preferably less than 3 millimetres.

[0068] In such embodiments, the body may have a thickness from 0.5 millimetres to 6 millimetres, from 0.5 millimetres to 5 millimetres, from 0.5 millimetres to 4 millimetres, or from 0.5 millimetres to 3 millimetres.

[0069] In such embodiments, the body may have a thickness from 0.75 millimetres to 6 millimetres, from 0.75 millimetres to 5 millimetres, from 0.75 millimetres to 4 millimetres, or from 0.75 millimetres to 3 millimetres.

[0070] In such embodiments, the body may have a thickness from 1 millimetre to 6 millimetres, from 1 millimetre to 5 millimetres, from 1 millimetre to 4 millimetres, or from 1 millimetre to 3 millimetres.

[0071] In certain preferred embodiments, a ratio between an equivalent outer diameter of the body and the thickness of the body is between 2 and 50.

[0072] The provision of relatively thin aerosol-generating beads may advantageously increase the surface area of the aerosol-generating substrate. This may improve aerosol generation of the aerosol-generating substrate. In addition, the provision of relatively thin aerosol-generating beads P / 90765.W001 may reduce the thermal inertia of the aerosol-generating substrate, which may advantageously lead to the aerosol-generating substrate increasing its temperature more efficiently when it is heated by a heating element of an aerosol-generating device. This may advantageously ensure aerosol is generated at an earlier point during the heating cycle of the aerosol-generating device.

[0073] In addition, a plurality of relatively thin aerosol-generating beads may be received in a relatively thin aerosol-generating article. The provision of a relatively thin aerosol-generating article may advantageously improve the efficiency of the heating of the entire aerosol-generating article, and by extension the aerosol-generating substrate received within the aerosol-generating article, by a heating element of an aerosol-generating device.

[0074] The ratio between an equivalent outer diameter of the body and the thickness of the body may for example be at least 3, at least 4, at least 5, at least 10, at least 15, at least 20, at least 25, or at least 30.

[0075] The ratio between an equivalent outer diameter of the body and the thickness of the body may for example be up to 45. For example, the ratio between an equivalent outer diameter of the body and the thickness of the body may be less than or equal to 40, less than or equal to 35, less than or equal to 30, less than or equal to 25, less than or equal to 20, less than or equal to 15, less than or equal to 10, less than or equal to 5, or less than or equal to 4.

[0076] The ratio between an equivalent outer diameter of the body and the thickness of the body may be between 2 and 45, between 2 and 40, between 2 and 35, between 2 and 30, between 2 and 25, between 2 and 20, between 2 and 15, between 2 and 10, between 2 and 5, or between

[0077] 2 and 4.

[0078] The ratio between an equivalent outer diameter of the body and the thickness of the body may be between 3 and 45, between 3 and 40, between 3 and 35, between 3 and 30, between 3 and 25, between 3 and 20, between 3 and 15, between 3 and 10, between 3 and 5, or between

[0079] 3 and 4.

[0080] The ratio between an equivalent outer diameter of the body and the thickness of the body may be between 4 and 45, between 4 and 40, between 4 and 35, between 4 and 30, between 4 and 25, between 4 and 20, between 4 and 15, between 4 and 10, or between 4 and 5.

[0081] The ratio between an equivalent outer diameter of the body and the thickness of the body may be between 5 and 45, between 5 and 40, between 5 and 35, between 5 and 30, between 5 and 25, between 5 and 20, between 5 and 15, or between 5 and 10.

[0082] The ratio between an equivalent outer diameter of the body and the thickness of the body may be between 10 and 45, between 10 and 40, between 10 and 35, between 10 and 30, between 10 and 25, between 10 and 20, or between 10 and 15.

[0083] The ratio between an equivalent outer diameter of the body and the thickness of the body may be between 15 and 45, between 15 and 40, between 15 and 35, between 15 and 30, between 15 and 25, or between 15 and 20. P / 90765.W001

[0084] The ratio between an equivalent outer diameter of the body and the thickness of the body may be between 20 and 45, between 20 and 40, between 20 and 35, between 20 and 30, or between 20 and 25.

[0085] The ratio between an equivalent outer diameter of the body and the thickness of the body may be between 25 and 45, between 25 and 40, between 25 and 35, or between 25 and 30.

[0086] The ratio between an equivalent outer diameter of the body and the thickness of the body may be between 30 and 45, between 30 and 40, or between 30 and 35.

[0087] The ratio between an equivalent outer diameter of the body and the thickness of the body may be between 35 and 45, or between 35 and 40.

[0088] The ratio between an equivalent outer diameter of the body and the thickness of the body may be between 40 and 50 or between 40 and 45.

[0089] The ratio between an equivalent outer diameter of the body and the thickness of the body may be between 45 and 50.

[0090] In an aerosol-generating substrate according to the present invention, the support element preferably comprises at least a supporting thread extending through the two or more aerosolgenerating beads. The at least one supporting thread may be substantially free of aerosol former. Alternatively, the at least one supporting thread may comprise a flavourant or a further aerosol former. For example, the supporting thread may comprise an absorbent material loaded with the flavourant or further aerosol former.

[0091] A diameter of the at least one supporting thread may for example be at least 0.25 millimetres. Preferably, a diameter of the at least one supporting thread is at least 0.3 millimetres. More preferably, a diameter of the at least one supporting thread is at least 0.4 millimetres. Even more preferably, a diameter of the at least one supporting thread is at least 0.5 millimetres.

[0092] A diameter of the at least one supporting thread may for example be up to 1.5 millimetres. Preferably, a diameter of the at least one supporting thread is less than or equal to 1 .2 millimetres. More preferably, a diameter of the at least one supporting thread is less than or equal to 1 millimetre. Even more preferably, a diameter of the at least one supporting thread is less than or equal to 0.8 millimetres.

[0093] In some examples, a diameter of the at least one supporting thread may be from 0.25 millimetres to 1.5 millimetres, preferably from 0.25 millimetres to 1.2 millimetres, more preferably from 0.25 millimetres to 1 millimetre, even more preferably from 0.25 millimetres to 0.8 millimetres.

[0094] In other examples, a diameter of the at least one supporting thread may be from 0.3 millimetres to 1.5 millimetres, preferably from 0.3 millimetres to 1.2 millimetres, more preferably from 0.3 millimetres to 1 millimetre, even more preferably from 0.3 millimetres to 0.8 millimetres.

[0095] In further examples, a diameter of the at least one supporting thread may be from 0.4 millimetres to 1.5 millimetres, preferably from 0.4 millimetres to 1.2 millimetres, more preferably from 0.4 millimetres to 1 millimetre, even more preferably from 0.4 millimetres to 0.8 millimetres. P / 90765.W001

[0096] In yet further examples, a diameter of the at least one supporting thread may be from 0.5 millimetres to 1.5 millimetres, preferably from 0.5 millimetres to 1.2 millimetres, more preferably from 0.5 millimetres to 1 millimetre, even more preferably from 0.5 millimetres to 0.8 millimetres.

[0097] In certain embodiments, a ratio between a diameter of the at least one supporting thread and an average bead size of the two or more aerosol-generating beads may be less than or equal to 0.8. Preferably, a ratio between a length of the at least one supporting thread and an average bead size of the two or more aerosol-generating beads is less than or equal to 0.6. More preferably, a ratio between a length of the at least one supporting thread and an average bead size of the two or more aerosol-generating beads is less than or equal to 0.5. Even more preferably, a ratio between a length of the at least one supporting thread and an average bead size of the two or more aerosol-generating beads is less than or equal to 0.4.

[0098] A ratio between a diameter of the at least one supporting thread and an average bead size of the two or more aerosol-generating beads may be at least 0.05. Preferably, a ratio between a diameter of the at least one supporting thread and an average bead size of the two or more aerosol-generating beads is at least 0.1. More preferably, a ratio between a diameter of the at least one supporting thread and an average bead size of the two or more aerosol-generating beads is at least 0.15. Even more preferably, a ratio between a diameter of the at least one supporting thread and an average bead size of the two or more aerosol-generating beads is at least 0.2.

[0099] For example, a ratio between a length of the at least one supporting thread and an average bead size of the two or more aerosol-generating beads is from 0.1 to 0.8, preferably from 0.1 to 0.6, more preferably from 0.1 to 0.5, even more preferably from 0.1 to 0.4. For example, a ratio between a length of the at least one supporting thread and an average bead size of the two or more aerosol-generating beads may be from 0.15 to 0.8, from 0.15 to 0.6, from 0.15 to 0.5, or from 0.15 to 0.4.

[0100] In some embodiments, the support element linking the two or more aerosol-generating beads may be made of a material that is inductively heatable. Advantageously, this may facilitate supplying heat to the beads and releasing aerosol species from the beads during use. For example, the support element may comprise a metal wire or a metal thread.

[0101] In certain embodiments, the support element preferably comprises at least a metal wire or metal thread extending through the two or more aerosol-generating beads.

[0102] In some embodiments, the two or more aerosol-generating beads comprise a first group of aerosol-generating beads and a second group of aerosol-generating beads, and the at least one supporting thread comprises a first supporting thread extending through the first group of aerosol-generating beads and a second supporting thread extending through the second group of aerosol-generating beads. P / 90765.W001

[0103] In said embodiments, the first supporting thread and the second supporting thread preferably extend substantially parallel to one another so that the first group of aerosol-generating beads and the second group of aerosol-generating beads are arranged in substantially parallel rows.

[0104] Further, the two or more aerosol-generating beads may comprise a third group of aerosolgenerating beads, and the at least one supporting thread further comprises a third supporting thread extending through the third group of aerosol-generating beads, the third supporting thread extending substantially parallel to the first supporting thread and the second supporting thread so that the first group of aerosol-generating beads, the second group of aerosol-generating beads and the third group of aerosol-generating beads are arranged in substantially coplanar parallel rows.

[0105] In embodiments wherein the aerosol-generating substrate comprises two or more groups of aerosol-generating beads and two or more supporting threads, each extending in parallel through the aerosol-generating beads of a respective one of the two or more groups of aerosolgenerating beads, the aerosol-generating substrate may additionally comprise one or more thread extending transversely (preferably orthogonally) to the parallel-extending supporting threads. This may advantageously increase the stability of the parallel rows in which the aerosolgenerating beads are arranged. For example, the transversely-extending thread or threads may be coupled with the parallel-extending threads to form a network of supporting threads.

[0106] Alternatively, the two or more aerosol-generating beads may further comprise a third group of aerosol-generating beads, and the at least one supporting thread further comprises a third supporting thread extending through the third group of aerosol-generating beads, the third supporting thread extend substantially parallel to the first supporting thread and the second supporting thread so that the first group of aerosol-generating beads, the second group of aerosolgenerating beads and the third group of aerosol-generating beads are arranged in non-coplanar parallel rows.

[0107] As a further alternative, the two or more aerosol-generating beads further comprise a third group of aerosol-generating beads, and the at least one supporting thread further comprises a third supporting thread extending through the third group of aerosol-generating beads, the third supporting thread extend substantially parallel to the first supporting thread and the second supporting thread; wherein the aerosol-generating substrate further comprises a flexible carrier sheet supporting the two or more aerosol-generating beads and the at least one supporting thread so that a configuration of the carrier sheet determines a spatial arrangement of the first group of aerosol-generating beads, the second group of aerosol-generating beads and the third group of aerosol-generating beads relative to each other. For example, the carrier sheet may be wound about a longitudinal axis of the carrier sheet. P / 90765.W001

[0108] According to yet another alternative arrangement, the two or more aerosol-generating beads further comprise a third group of aerosol-generating beads and the at least one supporting thread further comprises a third supporting thread extending through the third group of aerosolgenerating beads, the third supporting thread extend substantially parallel to the first supporting thread and the second supporting thread; wherein the aerosol-generating substrate further comprises a net supporting the two or more aerosol-generating beads and the at least one supporting thread so that a configuration of the net determines a spatial arrangement of the first group of aerosol-generating beads, the second group of aerosol-generating beads and the third group of aerosol-generating beads relative to each other.

[0109] In an aerosol-generating substrate according to the present invention, the support element may comprise a sheet of planar material. The sheet of planar material may be a length of carrier tape. The two or more aerosol-generating beads may be attached to the sheet of planar material.

[0110] The sheet of planar material may have a width which is at least 2 times the average bead size of the two or more aerosol-generating beads. For example, the sheet of planar material may have a width which is at least 4, at least 6, at least 8, or at least 9 times the average bead size of the two or more aerosol-generating beads.

[0111] The sheet of planar material may have a width which is no more than 2 times the average bead size of the two or more aerosol-generating beads. For example, the sheet of planar material may have a width which is no more than 20, no more than 18, no more than 16, or no more than 12 times the average bead size of the two or more aerosol-generating beads.

[0112] The sheet of planar material may have a width which is about 10 times the average bead size of the two or more aerosol-generating beads. Where this is the case, the aerosol-generating substrate may comprise at least one row of aerosol-generating beads along the width of the sheet of planar material. The aerosol-generating substrate may comprise a plurality of rows of aerosolgenerating beads along the length of the sheet of planar material, the length being perpendicular to the width. Alternatively, the two or more aerosol-generating beads may be randomly arranged on the sheet of planar material.

[0113] The two or more aerosol-generating beads may be arranged on only a first planar surface of the sheet of planar material. The two or more aerosol-generating beads may be arranged on both the a first and a second planar surface of the sheet of planar material.

[0114] The sheet of planar material may be a flexible material such that the aerosol-generating substrate may be rolled onto a bobbin.

[0115] The two of more aerosol-generating beads may be attached to the sheet of planar material by an adhesive. The adhesive may be applied as an adhesive layer on a planar surface of the sheet of planar material. Alternatively or in addition, the two or more aerosol-generating beads may be coated with an adhesive which promotes adhesion to the sheet of planar material and to surrounding beads of the two or more aerosol-generating beads. P / 90765.W001

[0116] The adhesive may comprise a hydrogel. The hydrogel may be a thermos-reactive Alg hydrogel. The hydrogel may also contribute to the aerosol generation.

[0117] As described briefly above, the aerosol-generating substrate may comprise an aerosol former. Preferably, the aerosol-generating substrate comprises at least 10 percent by weight of an aerosol former, on a dry weight basis. For example, the aerosol-generating substrate may comprise at least 15 percent by weight of an aerosol former, on a dry weight basis.

[0118] In certain embodiments, the aerosol-generating substrate comprises at least 18 percent by weight of an aerosol former, on a dry weight basis. Preferably, the aerosol-generating substrate comprises at least 20 percent by weight of an aerosol former, on a dry weight basis. More preferably, the aerosol-generating substrate comprises at least 25 percent by weight of an aerosol former, on a dry weight basis. Even more preferably, the aerosol-generating substrate comprises at least 30 percent by weight of an aerosol former, on a dry weight basis.

[0119] The aerosol-generating substrate may comprise less than or equal to 60 percent by weight of an aerosol former, on a dry weight basis.

[0120] Preferably, the aerosol-generating substrate comprises less than or equal to 55 percent by weight of an aerosol former, on a dry weight basis. More preferably, the aerosol-generating substrate comprises less than or equal to 50 percent by weight of an aerosol former, on a dry weight basis. Even more preferably, the aerosol-generating substrate comprises less than or equal to 45 percent by weight of an aerosol former, on a dry weight basis.

[0121] In some examples, the aerosol-generating substrate comprises from 10 percent by weight to 60 percent by weight, preferably from 10 percent by weight to 55 percent by weight, more preferably from 10 percent by weight to 50 percent by weight, even more preferably from 10 percent by weight to 45 percent by weight of an aerosol former, on a dry weight basis.

[0122] In other examples, the aerosol-generating substrate comprises from 15 percent by weight to 60 percent by weight, preferably from 15 percent by weight to 55 percent by weight, more preferably from 15 percent by weight to 50 percent by weight, even more preferably from 15 percent by weight to 45 percent by weight of an aerosol former, on a dry weight basis.

[0123] In further examples, the aerosol-generating substrate comprises from 18 percent by weight to 60 percent by weight, preferably from 18 percent by weight to 55 percent by weight, more preferably from 18 percent by weight to 50 percent by weight, even more preferably from 18 percent by weight to 45 percent by weight of an aerosol former, on a dry weight basis.

[0124] In yet further examples, the aerosol-generating substrate comprises from 20 percent by weight to 60 percent by weight, preferably from 20 percent by weight to 55 percent by weight, more preferably from 20 percent by weight to 50 percent by weight, even more preferably from 20 percent by weight to 45 percent by weight of an aerosol former, on a dry weight basis.

[0125] In yet other examples, the aerosol-generating substrate comprises from 25 percent by weight to 60 percent by weight, preferably from 25 percent by weight to 55 percent by weight, P / 90765.W001 more preferably from 25 percent by weight to 50 percent by weight, even more preferably from 25 percent by weight to 45 percent by weight of an aerosol former, on a dry weight basis.

[0126] Without wishing to be bound by theory, it is understood that aerosol former contents falling within the ranges described above provide a satisfactory balance between the need for structural stability and the desire to optimise release of aerosol from the aerosol-generating substrate upon heating.

[0127] The aerosol former may be any suitable compound or mixture of compounds that, in use, facilitates formation of a dense and stable aerosol and is substantially resistant to thermal degradation at the operating temperature of an aerosol-generating article comprising the aerosolgenerating substrate. Suitable aerosol formers are for example: polyhydric alcohols such as, for example, triethylene glycol, 1 ,3-butanediol, propylene glycol and glycerine; esters of polyhydric alcohols such as, for example, glycerol mono-, di- or triacetate; aliphatic esters of mono-, di- or polycarboxylic acids such as, for example, dimethyl dodecanedioate and dimethyl tetradecanedioate; and combinations thereof.

[0128] The aerosol former may comprise a polyhydric alcohol. The aerosol former may comprise one or more of glycerine and propylene glycol. The aerosol former may consist of glycerine or propylene glycol or of a combination of glycerine and propylene glycol. The aerosol former may comprise glycerine.

[0129] As described briefly above, the aerosol-generating substrate may comprise a cellulose- containing powder. For example, the aerosol-generating substrate may comprise at least 25 percent by weight of the cellulose-containing powder, on a dry weight basis.

[0130] Preferably, the aerosol-generating substrate comprises at least 30 percent by weight of the cellulose-containing powder, on a dry weight basis. More preferably, the aerosol-generating substrate comprises at least 40 percent by weight of the cellulose-containing powder, on a dry weight basis. Even more preferably, the aerosol-generating substrate comprises at least 50 percent by weight of the cellulose-containing powder, on a dry weight basis.

[0131] The aerosol-generating substrate may comprise less than or equal to 85 percent by weight of the cellulose-containing powder, on a dry weight basis. Preferably, the aerosol-generating substrate comprises less than or equal to 80 percent by weight of the cellulose-containing powder, on a dry weight basis. More preferably, the aerosol-generating substrate comprises less than or equal to 75 percent by weight of the cellulose-containing powder, on a dry weight basis.

[0132] For example, the aerosol-generating substrate may comprises from 25 percent by weight to 85 percent by weight of the cellulose-containing powder, preferably from 25 percent by weight to 80 percent by weight of the cellulose-containing powder, more preferably from 25 percent by weight to 75 percent by weight of the cellulose-containing powder of the cellulose-containing powder, on a dry weight basis. P / 90765.W001

[0133] In another example, the aerosol-generating substrate may comprises from 30 percent by weight to 85 percent by weight of the cellulose-containing powder, preferably from 30 percent by weight to 80 percent by weight of the cellulose-containing powder, more preferably from 30 percent by weight to 75 percent by weight of the cellulose-containing powder of the cellulose- containing powder, on a dry weight basis.

[0134] In a further example, the aerosol-generating substrate may comprises from 40 percent by weight to 85 percent by weight of the cellulose-containing powder, preferably from 40 percent by weight to 80 percent by weight of the cellulose-containing powder, more preferably from 40 percent by weight to 75 percent by weight of the cellulose-containing powder of the cellulose- containing powder, on a dry weight basis.

[0135] In yet a further example, the aerosol-generating substrate may comprises from 50 percent by weight to 85 percent by weight of the cellulose-containing powder, preferably from 50 percent by weight to 80 percent by weight of the cellulose-containing powder, more preferably from 50 percent by weight to 75 percent by weight of the cellulose-containing powder of the cellulose- containing powder, on a dry weight basis.

[0136] In certain embodiments, the cellulose-containing powder comprises a plant material powder.

[0137] Preferably, the plant material powder comprises tobacco powder. By the term “tobacco powder”, reference is made throughout the specification to fragments of the tobacco plant, particularly of the tobacco lamina, stems and stalk.

[0138] Alternatively, or in addition, the plant powder may comprise a non-tobacco plant material powder. For example, the non-tobacco plant material powder may comprise particles of one or more of: tea, coffee, star anise, lavender, clove, peppermint, chamomile, rosemary, eucalyptus, ginger, dill seed, thyme, oregano and cumin. With reference to a non-tobacco plant, the term plant material may refer to one or more of the plant leaf (lamina, stems, stalk), flowers, seeds, and so forth.

[0139] Thus, while in certain embodiments the cellulose-containing powder contains tobacco powder as the sole plant material powder, in other embodiments the cellulose-containing powder contains tobacco powder in combination with a non-tobacco plant material powder. In further embodiments, the cellulose-containing powder may contain non-tobacco plant material powder as the sole plant material powder.

[0140] For example, the plant material powder - and, in particular, the tobacco powder - may have an average particle size of at least 20 micrometres. For the purposes of the present invention, the term "particle size" is used to denote the largest cross sectional dimension of the individual particles of plant material. The term "average particle size” is used herein to refer to the arithmetic mean particle size for the particles of plant material. The particle size distribution for a sample of particulate material may be determined using a known sieve test. Particles having P / 90765.W001 the desired size may be obtained by passing a population of plant material particles through sieve of suitable mesh sizes, as has been described above.

[0141] Use of tobacco plant particles - or, more generally, plant particles - having an average particle size of 20 micrometres or more may help control how easily the tobacco particles may be dispersed and kept in suspension within the aerosol former, which helps in providing an homogenous distribution of plant particles throughout the aerosol-generating substrate.

[0142] Preferably, the plant material powder may have an average particle size of at least 25 micrometres. More preferably, the plant material powder may have an average particle size of at least 30 micrometres. Even more preferably, the plant material powder may have an average particle size of at least 35 micrometres.

[0143] For example, the plant material powder may have an average particle size of less than or equal to 220 micrometres. Preferably, the plant material powder has an average particle size of less than or equal to 200 micrometres. More preferably, the plant material powder may have an average particle size of less than or equal to 180 micrometres. Even more preferably, the plant material powder may have an average particle size of less than or equal to 160 micrometres.

[0144] In some examples, the plant material powder may have an average particle size from 25 micrometres to 200 micrometres, preferably from 25 micrometres to 180 micrometres, more preferably from 25 micrometres to 160 micrometres. In other examples, the plant material powder may have an average particle size from 25 micrometres to 200 micrometres, preferably from 30 micrometres to 180 micrometres, more preferably from 30 micrometres to 160 micrometres. In further examples, the plant material powder may have an average particle size from 35 micrometres to 200 micrometres, preferably from 35 micrometres to 180 micrometres, more preferably from 35 micrometres to 160 micrometres.

[0145] Advantageously, using tobacco plant particles - or, more generally, plant particles - having an average size within the ranges described above has a beneficial impact on flowability and malleability of the aerosol-generating substrate, and may also enable some desirable control over porosity of the formed aerosol-generating substrate, which helps in release of the aerosol species during use.

[0146] In some embodiments, the beads of an aerosol-generating substrate according to the present invention may comprise two or more types of plant material powder. That is, each bead may be formed from a mixture of different particles of plant material, such as particles of the same plant material differing by way of a physical parameter (for example, different particle size) or particles obtained from distinct parts of a same plant (for example, leaves and seeds) or particles obtained from different plants (for example, leaves of two different plants). Accordingly, in certain embodiments, a particle size distribution may be bimodal, trimodal, or generally multimodal, as each sub-population of particles in the mixture of different particles of plant material may generally have a different average particle size. P / 90765.W001

[0147] In embodiments wherein the cellulose-containing powder comprises a plant material powder comprising tobacco powder, the aerosol-generating substrate preferably comprises at least 65 percent by weight, more preferably at least 70 percent by weight, even more preferably at least 75 percent by weight of the tobacco powder, on a dry weight basis.

[0148] In embodiments wherein the cellulose-containing powder comprises a plant material powder comprising tobacco powder, the aerosol-generating substrate preferably comprises less than or equal to 85 percent by weight, more preferably less than or equal to 80 percent by weight of the tobacco powder, on a dry weight basis.

[0149] In certain examples, the aerosol-generating substrate comprises from 65 percent by weight to 80 percent by weight, preferably from 70 percent by weight to 80 percent by weight, more preferably from 75 percent by weight to 80 percent by weight of tobacco powder, on a dry weight basis. In other examples, the aerosol-generating substrate comprises from 65 percent by weight to 85 percent by weight, preferably from 70 percent by weight to 85 percent by weight, more preferably from 75 percent by weight to 85 percent by weight of tobacco powder, on a dry weight basis.

[0150] In embodiments wherein the cellulose-containing powder comprises a plant material powder comprising non-tobacco plant material powder, the aerosol-generating substrate preferably comprises at least 40 percent by weight, more preferably at least 45 percent by weight, even more preferably at least 50 percent by weight of the non-tobacco plant material powder.

[0151] In embodiments wherein the cellulose-containing powder comprises a plant material powder comprising non-tobacco plant material powder, the aerosol-generating substrate preferably comprises less than or equal to 60 percent by weight, more preferably less than or equal to 55 percent by weight of the non-tobacco plant material powder.

[0152] Without wishing to be bound by theory, contents of non-tobacco plant material powder falling within the ranges described above are considered to be associated with desirable levels of flavour species being released into the aerosol and delivered to the consumer. Accordingly, an aerosol-generating substrate in accordance with the present disclosure may advantageously be included in aerosol-generating articles or systems that provide the consumer with novel flavour delivery profiles.

[0153] In certain embodiments, the cellulose-containing powder may comprise microcrystalline cellulose in combination with a plant material powder as described above. The term “microcrystalline cellulose” (MCC) is used to describe a purified and partially depolymerized cellulose made of glucose units connected by p-1 ,4 glycosidic bonds.

[0154] Cellulose is a polysaccharide composed by p (1 — > 4) linked d-glucose units forming microfibrils in plant cells. These microfibrils bond together to create large crystalline regions with intervened amorphous parts. Microcrystalline cellulose (MCC) is obtained by hydrolytic depolymerisation of cellulose in order to isolate the crystalline regions with, usually, a subsequent P / 90765.W001 spray drying step to obtain dry and porous particles. Cellulose for MCC production is mainly derived from wood.

[0155] For example, the cellulose-containing powder may comprise at least 1 percent by weight of the microcrystalline cellulose, on a dry weight basis. Preferably, the cellulose-containing powder comprises at least 2 percent by weight of the microcrystalline cellulose, on a dry weight basis. More preferably, the cellulose-containing powder comprises at least 5 percent by weight of the microcrystalline cellulose, on a dry weight basis. Even more preferably, the cellulose- containing powder comprises at least 10 percent by weight of the microcrystalline cellulose, on a dry weight basis.

[0156] In other embodiments, the cellulose-containing powder is microcrystalline cellulose. In embodiments wherein the cellulose-containing powder is entirely provided as microcrystalline cellulose, the aerosol-generating substrate may comprise at least 45 percent by weight, preferably at least 50 percent by weight, more preferably at least 55 percent by weight of the microcrystalline cellulose, on a dry weight basis.

[0157] As an alternative to, or in addition to microcrystalline cellulose, the cellulose-containing powder may contain powdered cellulose. The term “powdered cellulose” is used to describe a non-modified, purified cellulose, obtained by the mechanical disintegration of alpha-cellulose procured in pulp form from fibrous plant material. Powdered cellulose is cellulose of food-grade quality.

[0158] In embodiments wherein the cellulose-containing powder is entirely provided as microcrystalline cellulose, the aerosol-generating substrate may comprise less than or equal to 70 percent by weight, preferably less than or equal to 65 percent by weight, more preferably less than or equal to 60 percent by weight of the microcrystalline cellulose.

[0159] In certain embodiments, the aerosol-generating substrate comprises from 45 percent by weight to 70 percent by weight, preferably from 50 percent by weight to 70 percent by weight, more preferably from 55 percent by weight to 70 percent by weight of the microcrystalline cellulose.

[0160] In other embodiments, the aerosol-generating substrate comprises from 45 percent by weight to 65 percent by weight, preferably from 50 percent by weight to 65 percent by weight, more preferably from 55 percent by weight to 65 percent by weight of the microcrystalline cellulose.

[0161] In further examples, the aerosol-generating substrate comprises from 45 percent by weight to 60 percent by weight, preferably from 50 percent by weight to 60 percent by weight, more preferably from 55 percent by weight to 60 percent by weight of the microcrystalline cellulose.

[0162] As described briefly above, the aerosol-generating substrate may optionally comprise a binder. P / 90765.W001

[0163] In some embodiments, the binder comprises hydroxypropyl methylcellulose (HPMC). Inclusion of HPMC in the formulation of the beads of an aerosol-generating substrate in accordance with the present disclosure may advantageously improve the binding of the particles of cellulose-containing powder - especially when the cellulose-containing powder comprises plant material particles - in the bodies of the beads, which may have a favourable impact on the structural integrity of the aerosol-generating substrate.

[0164] Other binders suitable for inclusion in an aerosol-generating substrate in accordance with the present invention comprise, but are not limited to, guar, starch, carboxymethyl cellulose (CMC), or combinations thereof.

[0165] As will be apparent from the foregoing description, beads of an aerosol-generating substrate according to the present disclosure may contain one or more different types of cellulose- containing powder.

[0166] Certain types of cellulose-containing powder, such as tobacco powder and non-tobacco plant material powder may be flavour-bearing. This means that these types of cellulose- containing powder contain intrinsic aroma compounds which are released when beads comprising these types of cellulose-containing are heated during use. The term “aroma compounds” is used to describe volatile molecules, typically having a molecular weight below 300 Da, which can bind to the olfactory receptors or the taste receptors or both and, as a result, be perceived as a smell or a flavour. Accordingly, when beads comprising these types of cellulose- containing powder are heated during use, the nature and proportion of the cellulose-containing powder in the beads may generally have an impact on a smell or flavour of the aerosol.

[0167] By contrast, other types of cellulose-containing powder, such as microcrystalline cellulose, are substantially free of intrinsic aroma compounds. Accordingly, when beads comprising these types of cellulose-containing powder are heated during use, the cellulose-containing powder essentially does not impact in any way a smell or flavour of the aerosol.

[0168] It will be understood that beads comprising substantially no flavour-bearing cellulose- containing powder may, however, comprise an extrinsic flavourant. That is, an extrinsic flavourant may be added to the formulation of the beads, so that extrinsic aroma compounds are released when the beads are heated during use.

[0169] Equally, beads comprising at least some flavour-bearing cellulose-containing powder may further comprise an extrinsic flavourant. By adding an extrinsic flavourant to the formulation of the beads, both intrinsic and extrinsic aroma compounds are released when the beads are heated during use.

[0170] An aerosol-generating substrate for use in an aerosol-generating article or system according to the present disclosure may comprise, in combination, both beads comprising flavourbearing cellulose-containing powder and beads that are substantially free of flavour-bearing cellulose-containing powder. Further, an extrinsic flavourant may optionally be added to either or P / 90765.W001 both the beads comprising flavour-bearing cellulose-containing powder and beads that are substantially free of flavour-bearing cellulose-containing powder.

[0171] In an aerosol-generating substrate for use in an aerosol-generating article or system according to the present disclosure, the plurality of beads may comprise two or more groups of beads differing from each other chemically or physically or both.

[0172] For example, the plurality of beads may comprise two or more groups of beads differing by way of at least one of the geometric parameters described above. As another example, the plurality of beads may comprise two or more groups of beads containing different proportions by weight of aerosol former on a dry weight basis, or different types of flavour-bearing cellulose- containing powder, and so forth.

[0173] In an aerosol-generating substrate for use in an aerosol-generating article or system according to the present disclosure, a first group of beads in line with the foregoing disclosure may also be optionally combined with a second group of beads not in line with the foregoing disclosure (for example, containing no aerosol former), the beads in the second group being formed from a cellulose-containing powder and comprising intrinsic aroma compounds or extrinsic aroma compounds or both.

[0174] Accordingly, a wide variety of flavour and smell profiles can be obtained with aerosolgenerating substrates in accordance with the present invention.

[0175] A method of producing an aerosol-generating substrate according to the present invention preferably comprises a first step of forming a mixture of cellulose-containing powder and aerosol former; optionally mixing the combined cellulose-containing powder and aerosol former with a binder to form a dough. Further, the method preferably comprises a second step of forming a plurality of aerosol-generating beads from the dough. Additionally, the method preferably comprises a third step of providing a support element and a fourth step of linking two or more of the aerosol-generating beads to provide the aerosol-generating substrate.

[0176] Certain characteristics of a bead, such as density, porosity and hardness shall generally depend on how the cellulose-containing powder, aerosol former and optional binder are processed to form the plurality of beads.

[0177] Preferably, the method comprises a further step of drying the beads that have been formed from the dough. This may be desirable to ensure that water activity of the formed beads is below a predetermined threshold value, so as to maximise the stability of the formed beads. Further, drying the formed beads may generally facilitate preserving the integrity of the formed beads.

[0178] An aerosol-generating substrate in accordance with the foregoing description may find use in a number of different aerosol-generating articles.

[0179] In a preferred embodiment, an aerosol-generating article comprises a cavity and an aerosol-generating substrate in line with the foregoing arranged within the cavity. P / 90765.W001

[0180] Preferably, in the aerosol-generating article a bulk density of the aerosol-generating substrate within the cavity is at least 0.3 milligrams / cubic millimetre. By the term “bulk density”, reference is made throughout this specification to the ratio of the weight of aerosol-generating substrate and the volume of the cavity. In general, the “bulk density” will be lower than the theoretical density corresponding to the ratio of the weight of a volume equivalent to the volume of the cavity that were completely filled with the cellulose-containing powder, aerosol former and optional binder. In this context, the bulk density of the aerosol-generating substrate in the aerosolgenerating article can be calculated by measuring the total mass of the aerosol-generating beads and dividing this by the volume of the cavity within which the aerosol-generating beads are arranged within the aerosol-generating article.

[0181] More preferably, in the aerosol-generating article a bulk density of the aerosol-generating substrate within the cavity is at least 0.325 milligrams / cubic millimetre. Even more preferably, in the aerosol-generating article a bulk density of the aerosol-generating substrate within the cavity is at least 0.345 milligrams / cubic millimetre.

[0182] In the aerosol-generating article a bulk density of the aerosol-generating substrate within the cavity is preferably less than or equal to 0.525 milligrams / cubic millimetre. More preferably, in the aerosol-generating article a bulk density of the aerosol-generating substrate within the cavity is less than or equal to 0.5 milligrams / cubic millimetre. Even more preferably, in the aerosol-generating article a bulk density of the aerosol-generating substrate within the cavity is less than or equal to 0.475 milligrams / cubic millimetre.

[0183] In certain embodiments, a bulk density of the aerosol-generating substrate within the cavity is preferably from 0.3 milligrams / cubic millimetre to 0.525 milligrams / cubic millimetre, more preferably from 0.325 milligrams / cubic millimetre to 0.525 milligrams / cubic millimetre, even more preferably from 0.345 milligrams / cubic millimetre to 0.525 milligrams / cubic millimetre.

[0184] In other embodiments, a bulk density of the aerosol-generating substrate within the cavity is preferably from 0.3 milligrams / cubic millimetre to 0.5 milligrams / cubic millimetre, more preferably from 0.325 milligrams / cubic millimetre to 0.5 milligrams / cubic millimetre, even more preferably from 0.345 milligrams / cubic millimetre to 0.5 milligrams / cubic millimetre.

[0185] In further embodiments, a bulk density of the aerosol-generating substrate within the cavity is preferably from 0.3 milligrams / cubic millimetre to 0.475 milligrams / cubic millimetre, more preferably from 0.325 milligrams / cubic millimetre to 0.475 milligrams / cubic millimetre, even more preferably from 0.345 milligrams / cubic millimetre to 0.475 milligrams / cubic millimetre.

[0186] 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 substrate for use in an aerosol-generating article or system, the aerosol-generating substrate comprising: two or more aerosol-generating beads and a support element linking the two or more aerosol-generating beads, wherein each aerosolgenerating bead comprises: a cellulose-containing powder; an aerosol former; and optionally a binder.

[0187] Example EX2. An aerosol-generating substrate according to example EX1 , wherein an average bead size of the two or more aerosol-generating beads is at least 1 millimetre.

[0188] Example EX3. An aerosol-generating substrate according to example EX1 or EX2, wherein an average bead size of the two or more aerosol-generating beads is less than or equal to 5 millimetres.

[0189] Example EX 4. An aerosol-generating substrate according to any one of the preceding examples, wherein each bead comprises a body and a channel extending through the body, the body being substantially disc-shaped or ring-shaped.

[0190] Example EX5. An aerosol-generating substrate according to example EX4, wherein an equivalent outer diameter of the body is at least 0.1 millimetres.

[0191] Example EX6. An aerosol-generating substrate according to example EX4 or example EX5, wherein an equivalent outer diameter of the body is less than or equal to 12 millimetres.

[0192] Example EX7. An aerosol-generating substrate according to any one of examples EX4 to EX6, wherein a ratio between an equivalent internal diameter of the channel and an equivalent outer diameter of the body is at least 0.13.

[0193] Example EX8. An aerosol-generating substrate according to any one of examples EX4 to EX6, wherein a ratio between an equivalent internal diameter of the channel and an equivalent outer diameter of the body is at least 0.25.

[0194] Example EX9. An aerosol-generating substrate according to any one of examples EX4 to EX8, wherein a ratio between an equivalent internal diameter of the channel and an equivalent outer diameter of the body is less than or equal to 0.9.

[0195] Example EX10. An aerosol-generating substrate according to any one of examples EX4 to EX9, wherein a thickness of the body is less than 50 percent of the smaller of a width and a length of the body.

[0196] Example EX11. An aerosol-generating substrate according to example EX10, wherein a thickness of the body is at least 0.1 millimetres.

[0197] Example EX12. An aerosol-generating substrate according to example EX10 or EX11 , wherein a thickness of the body is at less than or equal to 6 millimetres.

[0198] Example EX13. An aerosol-generating substrate according to any one of examples EX1 to EX12, wherein the support element comprises at least a supporting thread extending through the two or more aerosol-generating beads. P / 90765.W001

[0199] Example EX14. An aerosol-generating substrate according to any one example EX1 to EX13, wherein the at least one supporting thread is substantially free of aerosol former.

[0200] Example EX15. An aerosol-generating substrate according to any one examples EX1 to EX13, wherein the at least one supporting thread comprises a flavourant or a further aerosol former.

[0201] Example EX16. An aerosol-generating substrate according to any one of examples EX1 to EX15, wherein a ratio between a diameter of the at least one supporting thread and an average bead size of the two or more aerosol-generating beads is less than 0.8.

[0202] Example EX17. An aerosol-generating substrate according to any one of examples EX1 to EX15, wherein a ratio between a diameter of the at least one supporting thread and an average bead size of the two or more aerosol-generating beads is less than 0.6.

[0203] Example EX18. An aerosol-generating substrate according to any one of examples EX13 to EX17, wherein the two or more aerosol-generating beads comprise a first group of aerosol-generating beads and a second group of aerosol-generating beads and the at least one supporting thread comprises a first supporting thread extending through the first group of aerosolgenerating beads and a second supporting thread extending through the second group of aerosolgenerating beads.

[0204] Example EX19. An aerosol-generating substrate according to example EX18, wherein the first supporting thread and the second supporting thread extend substantially parallel to one another so that the first group of aerosol-generating beads and the second group of aerosol-generating beads are arranged in substantially parallel rows.

[0205] Example EX20. An aerosol-generating substrate according to example EX19 wherein the two or more aerosol-generating beads further comprise a third group of aerosolgenerating beads and the at least one supporting thread further comprises a third supporting thread extending through the third group of aerosol-generating beads, the third supporting thread extending substantially parallel to the first supporting thread and the second supporting thread so that the first group of aerosol-generating beads, the second group of aerosol-generating beads and the third group of aerosol-generating beads are arranged in substantially coplanar parallel rows.

[0206] Example EX21. An aerosol-generating substrate according to example EX19 wherein the two or more aerosol-generating beads further comprise a third group of aerosolgenerating beads and the at least one supporting thread further comprises a third supporting thread extending through the third group of aerosol-generating beads, the third supporting thread extend substantially parallel to the first supporting thread and the second supporting thread so that the first group of aerosol-generating beads, the second group of aerosol-generating beads and the third group of aerosol-generating beads are arranged in non-coplanar parallel rows. P / 90765.W001

[0207] Example EX22. An aerosol-generating substrate according to example EX19 wherein the two or more aerosol-generating beads further comprise a third group of aerosolgenerating beads and the at least one supporting thread further comprises a third supporting thread extending through the third group of aerosol-generating beads, the third supporting thread extend substantially parallel to the first supporting thread and the second supporting thread; wherein the aerosol-generating substrate further comprises a flexible carrier sheet supporting the two or more aerosol-generating beads and the at least one supporting thread so that a configuration of the carrier sheet determines a spatial arrangement of the first group of aerosolgenerating beads, the second group of aerosol-generating beads and the third group of aerosolgenerating beads relative to each other.

[0208] Example EX23. An aerosol-generating substrate according to example EX22, wherein the carrier sheet is wound about a longitudinal axis of the carrier sheet.

[0209] Example EX24. An aerosol-generating substrate according to example EX19 wherein the two or more aerosol-generating beads further comprise a third group of aerosolgenerating beads and the at least one supporting thread further comprises a third supporting thread extending through the third group of aerosol-generating beads, the third supporting thread extend substantially parallel to the first supporting thread and the second supporting thread; wherein the aerosol-generating substrate further comprises a net supporting the two or more aerosol-generating beads and the at least one supporting thread so that a configuration of the net determines a spatial arrangement of the first group of aerosol-generating beads, the second group of aerosol-generating beads and the third group of aerosol-generating beads relative to each other.

[0210] Example EX24a. An aerosol-generating substrate according to any one of examples EX1 to EX12, wherein the support element comprises a sheet of planar material, the two or more aerosol-generating beads being attached to the sheet of planar material.

[0211] Example EX24b. An aerosol-generating substrate according to example EX24a, further comprising an adhesive to attach the two or more aerosol-generating beads to the sheet of planar material.

[0212] Example EX24c. An aerosol-generating substrate according to example EX24b, wherein the adhesive is provided a layer of adhesive on a first surface of the sheet of planar material.

[0213] Example EX24d. An aerosol-generating substrate according to example EX24b, wherein the adhesive is provided as a coating on the two or more aerosol-generating beads.

[0214] Example EX24e. An aerosol-generating substrate according to any one of examples EX24a to EX24d, wherein the sheet of planar material is flexible. P / 90765.W001

[0215] Example EX25. An aerosol-generating substrate according to any one of examples EX1 to EX24e, wherein the aerosol-generating substrate comprises at least 10 percent by weight of the aerosol former, on a dry weight basis.

[0216] Example EX26. An aerosol-generating substrate according to any one of examples EX1 to EX25, wherein the aerosol-generating substrate comprises less than or equal to 60 percent by weight of an aerosol former, on a dry weight basis.

[0217] Example EX27. An aerosol-generating substrate according to any one of examples EX1 to EX26, wherein the aerosol former comprises glycerol or propylene glycol or both.

[0218] Example EX28. An aerosol-generating substrate according to any one of examples EX1 to EX27, wherein the aerosol-generating substrate comprises at least 30 percent by weight of the cellulose-containing powder, on a dry weight basis.

[0219] Example EX29. An aerosol-generating substrate according to any one of example EXs 1 to 28, wherein the cellulose-containing powder comprises a plant material powder.

[0220] Example EX30. An aerosol-generating substrate according to example EX29, wherein the plant material powder comprises tobacco powder.

[0221] Example EX31. An aerosol-generating substrate according to example EX30, wherein the tobacco powder has an average particle size of at least 25 micrometres.

[0222] Example EX32. An aerosol-generating substrate according to example EX29 or example EX30, wherein the tobacco powder has an average particle size of less than or equal to 200 micrometres.

[0223] Example EX33. An aerosol-generating substrate according to any one of examples EX29 to EX32, wherein the aerosol-generating substrate comprises at least 65 percent by weight of the tobacco powder, on a dry weight basis.

[0224] Example EX34. An aerosol-generating substrate according to any one of examples EX29 to EX32, wherein the aerosol-generating substrate comprises at least 70 percent by weight of the tobacco powder, on a dry weight basis.

[0225] Example EX35. An aerosol-generating substrate according to any one of examples EX29 to EX33, wherein the aerosol-generating substrate comprises at least 75 percent by weight of the tobacco powder, on a dry weight basis.

[0226] Example EX36. An aerosol-generating substrate according to any one of examples EX29 to EX35, wherein the aerosol-generating substrate comprises less than or equal to 85 percent by weight of the tobacco powder.

[0227] Example EX37. An aerosol-generating substrate according to any one of examples EX29 to EX36, wherein the aerosol-generating substrate comprises less than or equal to 80 percent by weight of the tobacco powder.

[0228] Example EX38. An aerosol-generating substrate according to example EX29, wherein the plant material powder comprises a non-tobacco plant material powder, preferably P / 90765.W001 comprising particles of one or more of: tea, coffee, star anise, lavender, clove, peppermint, chamomile, rosemary, eucalyptus, ginger, dill seed, thyme, oregano and cumin.

[0229] Example EX39. An aerosol-generating substrate according to example EX38, wherein the aerosol-generating substrate comprises at least 40 percent by weight of the nontobacco plant material powder, on a dry weight basis.

[0230] Example EX40. An aerosol-generating substrate according to example EX38 or example EX39, wherein the aerosol-generating substrate comprises at least 45 percent by weight of the non-tobacco plant material powder, on a dry weight basis.

[0231] Example EX41. An aerosol-generating substrate according to example EX38 or example EX39, wherein the aerosol-generating substrate comprises at least 50 percent by weight of the non-tobacco plant material powder, on a dry weight basis.

[0232] Example EX42. An aerosol-generating substrate according to any one of examples EX38 to EX41 , wherein the aerosol-generating substrate comprises less than or equal to 60 percent by weight of the non-tobacco plant material powder, on a dry weight basis.

[0233] Example EX43. An aerosol-generating substrate according to any one of examples EX38 to EX41 , wherein the aerosol-generating substrate comprises less than or equal to 55 percent by weight of the non-tobacco plant material powder, on a dry weight basis.

[0234] Example EX44. An aerosol-generating substrate according to any one of examples EX1 to EX43, wherein the cellulose-containing powder comprises microcrystalline cellulose or powdered cellulose or both.

[0235] Example EX45. An aerosol-generating substrate according to example EX44, wherein the aerosol-generating substrate comprises at least 1 percent by weight of the microcrystalline cellulose, on a dry weight basis.

[0236] Example EX46. An aerosol-generating substrate according to example EX44, wherein the aerosol-generating substrate comprises at least 10 percent by weight of the microcrystalline cellulose, on a dry weight basis

[0237] Example EX47. An aerosol-generating substrate according to any one of examples EX1 to EX28, wherein the cellulose-containing powder is microcrystalline cellulose.

[0238] Example EX48. An aerosol-generating substrate according to example EX47, wherein the aerosol-generating substrate comprises at least 50 percent by weight of the microcrystalline cellulose, on a dry weight basis.

[0239] Example EX49. An aerosol-generating substrate according to example EX47, wherein the aerosol-generating substrate comprises at least 55 percent by weight of the microcrystalline cellulose, on a dry weight basis.

[0240] Example EX50. An aerosol-generating substrate according to any one of examples EX47 to EX49, wherein the aerosol-generating substrate comprises less than or equal to 65 percent by weight of the microcrystalline cellulose, on a dry weight basis. P / 90765.W001

[0241] Example EX51. An aerosol-generating substrate according to any one of examples EX47 to EX49, wherein the aerosol-generating substrate comprises less than or equal to 60 percent by weight of the microcrystalline cellulose, on a dry weight basis.

[0242] Example EX52. An aerosol-generating substrate according to any one of the preceding examples, wherein the binder comprises hydroxypropyl methylcellulose (HPMC), guar, starch, carboxymethyl cellulose (CMC) or combinations thereof.

[0243] Example EX53. An aerosol-generating article comprising a cavity and an aerosolgenerating substrate according to any one of example EX1 to EX52 within the cavity.

[0244] Example EX54. An aerosol-generating article according to example EX53, wherein a bulk density of the aerosol-generating substrate within the cavity is at least 0.3 milligrams / cubic millimetre.

[0245] Example EX55. An aerosol-generating article according to example EX53 or example EX54, wherein a bulk density of the aerosol-generating substrate within the cavity is less than or equal to 0.5 milligrams / cubic millimetre.

[0246] Example Ex56. An aerosol-generating article according to any one of examples EX53 to EX55, wherein a thickness of the aerosol-generating article is preferably less than 50 percent of both a length and a width of the aerosol-generating article.

[0247] The invention will be further described, by way of example only, with reference to the accompanying drawings in which:

[0248] Figures 1 and 2 are schematic perspective views of examples of an aerosol-generating substrate according to the present invention, the aerosol-generating substrate comprising a group of aerosol-generating beads and a support element linking the aerosol-generating beads;

[0249] Figure 3 is a schematic perspective view of first example of an aerosol-generating substrate comprising multiple groups of aerosol-generating beads;

[0250] Figure 4 is a schematic top view of a second example of an aerosol-generating substrate comprising multiple groups of aerosol-generating beads;

[0251] Figure 5 is a schematic perspective view of a third example of an aerosol-generating substrate comprising multiple groups of aerosol-generating beads;

[0252] Figure 6 is a schematic perspective view of a fourth example of an aerosol-generating substrate comprising multiple groups of aerosol-generating beads;

[0253] Figure 7 is a schematic perspective view of an aerosol-generating article comprising an aerosol-generating substrate of the type shown in Figure 3;

[0254] Figure 8 shows an exploded perspective view of the aerosol-generating article of Figure 7; and

[0255] Figure 9 shows a schematic perspective view of a fifth example of an aerosol-generating substrate comprising a plurality of aerosol-generating beads on a sheet of planar material. P / 90765.W001

[0256] Figures 1 and 2 show schematic perspective views of two examples of aerosol-generating substrates 1000 and 2000 according to the present invention.

[0257] The aerosol-generating substrate 1000 comprises a plurality of disc-shaped beads 1010 and a supporting thread 1020 extending through the body of each one of the beads 1010.

[0258] Similarly, the aerosol-generating substrate 2000 comprises a plurality of ring-shaped beads 2010, wherein each bead 2010 comprises a body 2020 and a channel 2030 extending through the body 2020 along an axis of symmetry (not shown) of the body 2020. Further, the aerosol-generating substrate 2000 comprises a supporting thread 2040 extending through the channels of the beads 2010.

[0259] Figure 3 shows an example of an aerosol-generating substrate 3000 according to the present invention, which comprises: a first group 3010 of aerosol-generating beads 3012, a second group 3020 of aerosol-generating beads 3022, and a third group 3030 of aerosolgenerating beads 3032. The aerosol-generating beads 3012, 3022, and 3032 are all disc-shaped beads like in the aerosol-generating substrate 1000 of Figure 1. The aerosol-generating beads in groups 3010, 3020, 3030 may all have the same formulation. Alternatively, aerosol-generating beads in different groups may have different formulations.

[0260] The aerosol-generating substrate 3000 further comprises a first supporting thread 3014 extending through the first group 3010 of aerosol-generating beads 3012; a second supporting thread 3024 extending through the second group 3020 of aerosol-generating beads 3022; and a third supporting thread 3034 extending through the third group 3030 of aerosol-generating beads 3032.

[0261] The first, second and third supporting threads 3014, 3024 and 3034 extend parallel to each other and are substantially co-planar. Thus, the first group 3010 of aerosol-generating beads 3012, the second group 3020 of aerosol-generating beads 3022 and the third group 3030 of aerosol-generating beads 3032 are arranged in substantially coplanar, parallel rows.

[0262] As in the example illustrated in Figure 3, the first, second and third supporting threads 3014, 3024 and 3034 may be connected to each other, such as by being consecutive portions of a single longer thread. In alternative examples (not shown), the first, second and third supporting threads may be distinct portions of supporting thread material.

[0263] Figure 4 shows another example of an aerosol-generating substrate 4000 according to the present invention, which comprises: a first group 4010 of aerosol-generating beads 4012, a second group 4020 of aerosol-generating beads 4022, and a third group 4030 of aerosolgenerating beads 4032. The aerosol-generating beads 4012, 4022, and 4032 are all ring-shaped beads like in the aerosol-generating substrate 2000 of Figure 2. The aerosol-generating beads in groups 4010, 4020, 4030 may all have the same formulation. Alternatively, aerosol-generating beads in different groups may have different formulations. P / 90765.W001

[0264] The aerosol-generating substrate 4000 further comprises a first supporting thread 4014 extending through the first group 4010 of aerosol-generating beads 4012; a second supporting thread 4024 extending through the second group 4020 of aerosol-generating beads 4022; and a third supporting thread 4034 extending through the third group 4030 of aerosol-generating beads 3032.

[0265] The first, second and third supporting threads 4014, 4024 and 4034 extend parallel to each other and are substantially co-planar. Thus, the first group 4010 of aerosol-generating beads 4012, the second group 4020 of aerosol-generating beads 4022 and the third group 4030 of aerosol-generating beads 4032 are arranged in substantially coplanar, parallel rows.

[0266] As in the example illustrated in Figure 4, the first, second and third supporting threads 4014, 4024 and 4034 may be connected to each other, such as by being consecutive portions of a single longer thread. In alternative examples (not shown), the first, second and third supporting threads may be distinct portions of supporting thread material.

[0267] Additionally, in the example of Figure 4, the aerosol-generating substrate further comprises a plurality of threads 4050 extending transversely (orthogonally) to the first, second and third supporting threads 4014, 4024 and 4034 to form a supporting network which further stabilises the arrangement of the aerosol-generating beads in substantially coplanar, parallel rows.

[0268] Figure 5 shows yet another example of an aerosol-generating substrate 5000 according to the present invention, which comprises six groups 5010, 5020, 5030, 5040, 5050, 5060 of aerosol-generating beads 5012, 5022, 5032, 5042, 5052, 5062 wherein all the aerosol-generating beads are disc-shaped beads like in the aerosol-generating substrate 1000 of Figure 1. The aerosol-generating beads in the six groups 5010, 5020, 5030, 5040, 5050, 5060 may all have the same formulation. Alternatively, aerosol-generating beads in different groups may have different formulations.

[0269] The aerosol-generating substrate 5000 further comprises six supporting threads 5014, 5024, 5034, 5044, 5054, 5064, each of which extends through the aerosol-generating beads of a respective one of groups 5010, 5020, 5030, 5040, 5050, 5060.

[0270] The six supporting threads 5014, 5024, 5034, 5044, 5054, 5064 extend parallel to each other, but not in co-planar fashion. In fact, the aerosol-generating substrate 5000 may be regarded as a bundle of six linear aerosol-generating substrates of the type shown in Figure 1 , wherein the six linear aerosol-generating substrates are collated together in a quasi-cylindrical arrangement.

[0271] Figure 6 shows a further example of an aerosol-generating substrate 6000 according to the present invention, which - similar to the aerosol-generating substrate 5000 - comprises a plurality of groups 6010 of aerosol-generating beads 6020, the aerosol-generating beads 6020 in each group 6010 linked by a respective supporting thread 6030. P / 90765.W001

[0272] In contrast to the aerosol-generating substrate 5000, the aerosol-generating substrate 6000 further comprises a flexible carrier sheet 6040 supporting the groups 6010 of aerosolgenerating beads 6020 and the respective supporting thread 6030, so that a configuration of the carrier sheet 6040 determines a spatial arrangement of the groups 6010 of aerosol-generating beads 6020 relative to each other. For example, in the embodiment illustrated in Figure 6, the carrier sheet 6040 is wound around a longitudinal axis of the carrier sheet (not shown) which comes to coincide with a longitudinal axis of the aerosol-generating substrate 6000. As a result, the groups 6010 of aerosol-generating beads 6020 and the respective supporting threads 6030 are arranged as substantially parallel rows of beads, the rows of beads arranged in a spiral relative to the longitudinal axis of the aerosol-generating substrate.

[0273] Figure 7 shows an aerosol-generating article 10 comprising a first planar external layer 24 forming a first planar external surface 21 , a second planar external layer 25 forming a second planar external surface 22, and a frame 50 positioned between the first planar external layer 24 and the second planar external layer 25. The first planar external layer 24 and the second planar external layer 25 may be formed from a non-aerosol forming material, such as paper or card. Alternatively, either of the first planar external layer 24 and the second planar external layer 25 may comprise an aerosol-generating substrate comprising an aerosol-generating material, for example tobacco.

[0274] The aerosol-generating article 10 has a length extending in the x-direction, a width extending in the y-direction and a thickness extending in the z-direction. The aerosol-generating article 10 has a length of 30 millimetres, a width of 10 millimetres, and a thickness of 3.1 millimetres.

[0275] The first planar external surface 21 and the second planar external surface 22 extend in the x-direction and the y-direction. That is, the first planar external surface 21 and the second planar external surface 22 extend in the x / y plane. The first planar external surface 21 is positioned parallel to the second planar external surface 22 and the first planar external surface

[0276] 21 is spaced from the second planar external surface 22 in the z-direction or transverse direction. The distance between the first planar external surface 21 and the second planar external surface

[0277] 22 in the z-direction or transverse direction corresponds to the thickness of the aerosol-generating article 10.

[0278] The aerosol-generating article 10 is a substantially flat aerosol-generating article or substantially planar aerosol-generating article. In particular, the thickness of the aerosolgenerating article 10 is less than 50 percent of both the length and the width of the aerosolgenerating article. The aerosol-generating article 10 has a generally rectangular cuboid shape and a laminated structure formed by the first planar external layer 24, the frame 50 and the second planar external layer 25. The first planar external layer 24, the frame 50 and the second planar external layer 25 are bonded together with an adhesive, in particular guar gum. P / 90765.W001

[0279] Figure 8 shows an exploded view of the aerosol-generating article 10 of Figure 7.

[0280] The frame 50 has a length of 30 millimetres, a width of 10 millimetres, and a thickness of 2.7 millimetres. The frame 50 is made from cardboard and defines a frame aperture extending through the thickness of the frame 50. The frame aperture at least partially forms a cavity 30. The cavity 30 has length of 26 millimetres, a width of 6 millimetres, and a thickness of 2.7 millimetres. Therefore, the cavity 30 has a volume of about 421.2 cubic millimetres.

[0281] The cavity 30 is filled with groups of aerosol-generating beads of an aerosol-generating substrate 40 in accordance with the present disclosure (shown schematically). For example ,the aerosol-generating substrate 40 may be of the type described above with reference to the drawing of Figure 3. The beads of aerosol-generating substrate 40 are disposed within the volume of the cavity 30 so that airflow through the cavity 30 is provided by interstices between adjacent beads and (if present) by any channels extending through the bodies of the beads.

[0282] The first planar external layer 24 and the second planar external layer 25 have a thickness of 200 micrometres and are in physical contact with the frame 50. The first planar external layer 24 and the second planar external layer 25 are bonded to the frame with an adhesive 15. The first planar external layer 24 overlies an end of the cavity 30 and forms a first cavity end wall 31. The second planar external layer 25 overlies an opposite end of the cavity 30 and forms a second cavity end wall 32. That is, the frame 50, the first planar external layer 24 and the second planar external layer 25 collectively define the cavity 30.

[0283] The frame 50 comprises a peripheral wall 51 that circumscribes the cavity 30. The peripheral wall 51 has a radial thickness of about 2 millimetres.

[0284] An air inlet (not visible) and an air outlet 12 are defined by, and extend through, the peripheral wall 51 of the frame 50. The air inlet is positioned opposite the air outlet 12, on the opposite wall of the frame 50. The air inlet and the air outlet 12 each have a rectangular crosssection, a width of 2 millimetres, and a thickness of 0.9 millimetres. An airflow passage extends between the air inlet and the air outlet 12 through the cavity 30.

[0285] The beads of aerosol-generating substrate 40 may have the shape and size described above with reference to the drawing of Figure 1. The total weight of the beads of aerosolgenerating substrate 40 in the cavity 30 may be approximately 150 mg. The beads are formed of an aerosol-generating substrate comprising plant particles, aerosol former and optionally a binder.

[0286] Suitable formulations for forming a dough comprising cellulose-containing powder, aerosol former and optionally a binder, from which beads of an aerosol-generating substrate according to the present invention can be formed are described below.

[0287] Preparation A - Beads containing tobacco plant material and glycerine

[0288] 96 g of glycerine are mixed with 340 g of tobacco powder in a beaker to obtain a dispersion of tobacco powder in glycerine. 4 g of HPMC are dissolved in 10 g of glycerine to obtain a solution of HPMC in glycerine. 120 g of water are added to the solution of HPMC in glycerine. The dispersion of tobacco powder in glycerine and the solution of HPMC in glycerine and water combined to form a dough. The dough is extruded into a tubular element, which is subsequently cut into segments. The cut segments are then dried.

[0289] Preparation B - Beads containing tobacco plant material, microcrystalline cellulose and

[0290] 5 g of microcrystalline cellulose (MCC) are dispersed in 20 g of glycerine. 40 g of water are added to the dispersion of MCC in glycerine. 175 g of tobacco powder are weighed in a separate beaker. 25 g of glycerine and 25 g of water are added to the tobacco powder to form a dispersion of tobacco powder in glycerine and water. The two dispersions are mixed to obtain a dough. The dough is extruded into a tubular element, which is subsequently cut into segments. The cut segments are then dried.

[0291] Preparation C - Beads containing microcrystalline cellulose and glycerine

[0292] 80 g of glycerine are mixed with 170 g of microcrystalline cellulose (MCC) in a beaker to obtain a dispersion of MCC in glycerine. 2 g of HPMC are dissolved in 80 g of glycerine to obtain a solution of HPMC in glycerine. 60 g of water are added to the solution of HPMC in glycerine. The dispersion of MCC in glycerine and the solution of HPMC in glycerine and water combined to form a dough. The dough is extruded into a tubular element, which is subsequently cut into segments. The cut segments are then dried.

[0293] Preparation D - Beads containing non-tobacco plant material (hops) and glycerine

[0294] 4 g of HPMC are dissolved in 146.6 g of glycerine to obtain a solution of HPMC in glycerine. 100 g of water are added to the solution of HPMC in glycerine. 90 g of hops particles are weighed and added step-wise to the solution of HPMC in glycerine to form a dough. The dough is extruded into a tubular element, which is subsequently cut into segments. The cut segments are then dried.

[0295] Preparation E - Beads containing non-tobacco plant material (cloves) and glycerine

[0296] 0.75 g of HPMC are dissolved in 19 g of glycerine to obtain a solution of HPMC in glycerine. 21 g of water are added to the solution of HPMC in glycerine. 59 g of clove particles are weighed and added step-wise to the solution of HPMC in glycerine. 15 g of glycerol, 5.6 g of MCC and 10.8 g of water are added to the clove-containing, solution of HPMC in glycerine to form a dough. The dough is extruded into a tubular element, which is subsequently cut into segments. The cut segments are then dried.

[0297] Figure 9 shows a further example of an aerosol-generating substrate 9000 according to the present invention. The aerosol-generating substrate 9000 comprises a plurality of aerosolgenerating beads 9010. Each of the plurality of aerosol-generating beads 9010 may be as described above in relation to Figures 1 to 8. The aerosol-generating substrate 9000 further comprises a support element in the form of a sheet of planar material 9020. The sheet of planar P / 90765.W001 material 9020 comprises a flexible material such that the sheet of planar material 9020 may be rolled up. The sheet of planar material 9020 has a width W and an orthogonal length L, the length being greater than the width.

[0298] The aerosol-generating substrate 9000 comprises a layer of adhesive 9030 on a first planar surface of the sheet of planar material 9020. The plurality of aerosol-generating beads are provided on the first surface of the sheet of planar material 9020. The width W of the sheet of planar material is about 10x the size of the aerosol-generating beads 9010.

[0299] 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 ± 10 percent 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

-36-P / 90765.W001CLAIMS1. An aerosol-generating substrate for use in an aerosol-generating article or system, the aerosol-generating substrate comprising: two or more aerosol-generating beads; and a support element linking the two or more aerosol-generating beads, wherein each aerosol-generating bead comprises: a cellulose-containing powder; an aerosol former; and optionally a binder.

2. An aerosol-generating substrate according to claim 1 , wherein an average bead size of the two or more aerosol-generating beads is at least 1 millimetre.

3. An aerosol-generating substrate according to claim 1 or 2, wherein an average bead size of the two or more aerosol-generating beads is less than or equal to 12 millimetres.

4. An aerosol-generating substrate according to any one of the preceding claims, wherein each bead comprises a body and a channel extending through the body, the body being substantially disc-shaped or ring-shaped.

5. An aerosol-generating substrate according to claim 4, wherein a ratio between an equivalent internal diameter of the channel and an equivalent outer diameter of the body is at least 0.25.

6. An aerosol-generating substrate according to claim 4 or 5, wherein a ratio between an equivalent internal diameter of the channel and an equivalent outer diameter of the body is less than or equal to 0.9.

7. An aerosol-generating substrate according to any one of claims 4 to 6, wherein a thickness of the body is less than 50 percent of the smaller of a width and a length of the body.

8. An aerosol-generating substrate according to any one of claims 1 to 7, wherein the support element comprises at least a supporting thread extending through the two or more aerosolgenerating beads.-37-P / 90765.W0019. An aerosol-generating substrate according to claim 8, wherein the two or more aerosolgenerating beads comprise a first group of aerosol-generating beads and a second group of aerosol-generating beads and the at least one supporting thread comprises a first supporting thread extending through the first group of aerosol-generating beads and a second supporting thread extending through the second group of aerosol-generating beads.

10. An aerosol-generating substrate according to any one of claims 1 to 9, wherein the aerosol-generating substrate comprises at least 10 percent by weight of the aerosol former, on a dry weight basis.

11. An aerosol-generating substrate according to any one of claims 1 to 10, wherein the aerosol-generating substrate comprises at least 30 percent by weight of the cellulose-containing powder, on a dry weight basis.

12. An aerosol-generating substrate according to any one of claims 1 to 11 , wherein the cellulose-containing powder comprises a plant material powder.

13. An aerosol-generating substrate according to claim 12, wherein the plant material powder comprises tobacco powder.

14. An aerosol-generating substrate according to claim 12, wherein the plant material powder comprises a non-tobacco plant material powder.

15. An aerosol-generating article comprising a cavity and an aerosol-generating substrate according to any one of claims 1 to 14 within the cavity.

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