Aerosol-generating substrate with non-tobacco plant particles

Abstract

An aerosol-generating substrate (12)(212) comprises a homogenised plant material, the homogenised plant material comprising: at least 50 percent by weight of non-tobacco plant particles on a dry weight basis, the non-tobacco plant particles selected from: black tea particles, apple fibre particles, rosehip seed particles, lemon balm stem particles and combinations thereof, wherein the D90 value of the non-tobacco plant particles is less than 150 microns; at least 10 percent by weight of aerosol former on a dry weight basis; at least 2 percent by weight of exogenous binder on a dry weight basis; at least 2 percent by weight of additional fibres on a dry weight basis; and at least 0.5 percent by weight of active agent on a dry weight basis.

Description

[0001] AEROSOL-GENERATING SUBSTRATE WITH NON-TOBACCO PLANT PARTICLES

[0002] The present invention relates to an aerosol-generating substrate comprising non-tobacco plant particles and an active agent. The present invention further relates to an aerosol-generating article comprising such an aerosol-generating substrate and to a method of production of the aerosol-generating substrate.

[0003] Aerosol-generating articles in which an aerosol-generating substrate, such as a tobaccocontaining substrate, is heated rather than combusted, are known in the art. Typically in such articles, an aerosol is generated by the transfer of heat from a heat source to a physically separate aerosol-generating substrate or material, which may be located in contact with, within, around, or downstream of the heat source. During use of the aerosol-generating article, volatile compounds are released from the substrate by heat transfer from the heat source and are entrained in air drawn through the article. As the released compounds cool, they condense to form an aerosol.

[0004] Some aerosol-generating articles comprise a flavourant that is delivered to the consumer during use of the article to provide a different sensory experience to the consumer, for example to enhance the flavour of aerosol. A flavourant can be used to deliver a gustatory sensation (taste), an olfactory sensation (smell), or both a gustatory and an olfactory sensation to the user inhaling the aerosol. It is known to provide heated aerosol-generating articles that include flavourants.

[0005] There are difficulties involved in replicating the sensory experience provided by conventional combustible cigarettes with aerosol-generating articles in which the aerosolgenerating substrate is heated rather than combusted. This is partially due to the lower temperatures reached during the heating of such aerosol-generating articles, leading to a different profile of volatile compounds being released. It has also been found to be difficult to generate a sufficient level of aerosol from substrates containing a relatively high level of non-tobacco plant materials. With such materials, it can also be challenging to provide an acceptable balance of flavour and delivery of nicotine or other active agents from the substrate. It can also be challenging to effectively control the levels of nicotine or other active agents that are delivered, such that a consistent delivery of the active agent can be achieved.

[0006] It would be desirable to provide a novel aerosol-generating substrate for a heated aerosolgenerating article providing an improved and more consistent delivery of active agent to the consumer. It would be further desirable to provide such an aerosol-generating substrate which enables greater control of the balance between the active agent and any flavourants that are delivered upon heating of the substrate. It would also be desirable to provide such an aerosolgenerating substrate that can be readily incorporated into an aerosol-generating article and which can be manufactured using existing high-speed methods and apparatus. The present disclosure relates to an aerosol-generating substrate for use in an aerosolgenerating article or aerosol-generating system. The aerosol-generating substrate may comprise non-tobacco plant particles. The aerosol-generating substrate may comprise at least 50 percent by weight of the non-tobacco plant particles, on a dry weight basis. The non-tobacco plant particles may be selected from: black tea particles, apple fibre particles, rosehip seed particles, lemon balm stem particles and combinations thereof. The aerosol-generating substrate may further comprise an aerosol former. The aerosol-generating substrate may comprise at least 10 percent by weight of the aerosol former, on a dry weight basis. The aerosol-generating substrate may further comprise an exogenous binder. The aerosol-generating substrate may comprise at least 2 percent by weight of the exogenous binder, on a dry weight basis. The aerosol-generating substrate may further comprise additional fibres. The aerosol-generating substrate may comprise at least 2 percent by weight of additional fibres, on a dry weight basis. The aerosol-generating substrate may further comprise an active agent. The aerosol-generating substrate may comprise at least 2 percent by weight of the active agent, on a dry weight basis.

[0007] The invention is as defined in the claims below.

[0008] 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: at least 50 percent by weight of non-tobacco plant particles on a dry weight basis, the non-tobacco plant particles selected from: black tea particles, apple fibre particles, rosehip seed particles, lemon balm stem particles and combinations thereof; at least 10 percent by weight of aerosol former on a dry weight basis; at least 2 percent by weight of exogenous binder on a dry weight basis; at least 2 percent by weight of additional fibres on a dry weight basis; and at least 0.5 percent by weight of active agent on a dry weight basis.

[0009] Further, the present disclosure relates to an aerosol-generating article. The aerosolgenerating article may comprise a rod of the aerosol-generating substrate as described above.

[0010] According to the present invention there is provided an aerosol-generating article comprising a rod of the aerosol-generating substrate according to the present invention, as defined above.

[0011] Further, the present disclosure relates to a method of producing the aerosol-generating substrate as described above. The method may comprise the step of forming a slurry comprising non-tobacco plant particles, aerosol former, exogenous binder, additional fibres, active agent and water. The method may comprise the step of casting the slurry in the form of a sheet. The method may comprise the step of drying the sheet at between 80 and 160 degrees Celsius. The non- tobacco plant particles are selected from black tea particles, apple fibre particles, rosehip seed particles, lemon balm stem particles and combinations thereof.

[0012] According to the present invention, there is provided a method for producing an aerosolgenerating substrate according to the invention, as defined above. The method comprises the steps of: forming a slurry comprising non-tobacco plant particles, aerosol former, exogenous binder, additional fibres, active agent and water; casting the slurry in the form of a sheet; and drying the sheet at between 80 and 160 degrees Celsius. The non-tobacco plant particles are selected from black tea particles, apple fibre particles, rosehip seed particles, lemon balm stem particles and combinations thereof.

[0013] The present invention provides a novel material which uses one of the specific non- tobacco plant materials as defined above to provide the main structural component of the material and to act as a fibrous carrier for the active agent and any other optional components, such as flavourants. The specific non-tobacco plant materials each provide a homogenised plant material which has desirable physical properties, but have a low or minimal impact on the sensorial properties of the aerosol generated from the material. The non-tobacco plant materials therefore provide a relatively neutral or inert base material with which the active agent and any optional flavourants can be combined. In this way, the delivery of the active agent and any optional flavourants from the homogenised plant material can be more readily controlled compared to alternative homogenised plant materials in which the active agent and flavourants are generated from the plant materials themselves.

[0014] The inventors have also found that this combination of the specific non-tobacco plant particles as defined above with an active agent such as nicotine enables the aerosol-generating substrates to advantageously be formed with a reduced (or zero) level of tobacco particles, which means that the levels of undesirable tobacco compounds in the aerosol are reduced whilst still maintaining an acceptable delivery of nicotine or other active agent.

[0015] Advantageously, aerosol-generating articles according to the present invention may be manufactured with the same external dimensions as known aerosol-generating articles. Therefore, users of aerosol-generating articles according to the invention can use them with existing aerosol-generating devices. A further advantage of aerosol-generating articles according to the invention is that since the dimensions of the articles are substantially unchanged, they can be packaged in existing packaging solutions. Aerosol-generating articles according to the present invention can be manufactured efficiently and at high speed using existing manufacturing techniques and machinery.

[0016] As used herein, the term “aerosol-generating article” refers to an article wherein an aerosolgenerating substrate is heated to produce and deliver an inhalable aerosol to a consumer.

[0017] As used herein, the term “aerosol-generating substrate” refers to a substrate capable of releasing upon heating volatile compounds, which can form an aerosol. A conventional cigarette is lit when a user applies a flame to one end of the cigarette and draws air through the other end. The localised heat provided by the flame and the oxygen in the air drawn through the cigarette causes the end of the cigarette to ignite, and the resulting combustion generates an inhalable smoke. By contrast, in heated aerosol-generating articles, an aerosol is generated by heating an aerosol-generating substrate, such as tobacco. Known heated aerosol-generating articles include, for example, electrically heated aerosol-generating articles and aerosol-generating articles in which an aerosol is generated by the transfer of heat from a combustible fuel element or heat source to a physically separate aerosol-generating substrate.

[0018] As used herein with reference to the invention, the term “homogenised plant material” denotes a material formed by agglomerating particulate plant material.

[0019] As used herein, “aerosol-generating device” refers to a device that interacts with an aerosolgenerating substrate to generate an aerosol. Preferably, the aerosol-generating device is a device that interacts with an aerosol-generating substrate to generate an inhalable aerosol that is directly inhalable into a user’s lungs thorough the user's mouth.

[0020] As used herein, “aerosol-generating system” typically refers to the combination of an aerosol-generating device with an aerosol-generating substrate, preferably where the aerosolgenerating substrate is comprised in an aerosol-generating article. In an aerosol-generating system, the aerosol-generating substrate and the aerosol-generating device cooperate to generate an aerosol.

[0021] As used herein with reference to the present disclosure, the term “aerosol” is used to describe 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.

[0022] As used herein, “length” refers to the maximum dimension of a feature in a longitudinal direction of the feature. The term “length” denotes the dimension of a component of the aerosolgenerating article in the longitudinal direction, from the component’s furthest upstream point to the component’s furthest downstream point. For example, it may be used to denote the dimension of aerosol-generating substrate or of any elongate tubular elements in the longitudinal direction.

[0023] As used herein, the term “plug” denotes a generally cylindrical element having a substantially polygonal, circular, oval or elliptical cross-section. As used herein, the term “rod” refers to a generally cylindrical element of substantially polygonal cross-section and preferably of circular, oval or elliptical cross-section. A rod may have a length greater than or equal to the length of a plug. Typically, a rod has a length that is greater than the length of a plug. A rod may comprise one or more plugs, preferably aligned longitudinally.

[0024] As used herein, “upstream” and “downstream” describe the relative positions of elements, or portions of elements, of the aerosol-generating article in relation to the direction in which the aerosol is transported through the aerosol-generating article during use. During use, air is drawn through the aerosol-generating article in the longitudinal direction.

[0025] As used herein, “dry weight” 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. The composition of aqueous mixtures may be referred to by “percentage dry weight.” This refers to the weight of the non-water components relative to the weight of the entire aqueous mixture, expressed as a percentage.

[0026] As used throughout the present disclosure, the term “hollow tubular element” denotes a generally elongate element defining a lumen or airflow passage along a longitudinal axis thereof.

[0027] As defined above, the aerosol-generating substrate of the present invention comprises a homogenised plant material comprising at least 50 percent by weight of non-tobacco plant particles selected from: black tea particles, apple fibre particles, rosehip seed particles, lemon balm stem particles and combinations thereof. The non-tobacco plant particles may derive from a single non-tobacco plant material from this list, or a combination of two or more different plant materials from this list. Preferably, the non-tobacco plant particles are selected from black tea particles, apple fibre particles, or a combination thereof. Any references in the present disclosure to “non-tobacco plant particles” refers to the particles derived from the one or more specific non- tobacco plants defined above.

[0028] As used herein, the term “black tea particles” encompasses particles derived from dried black tea leaves. Black tea is derived from the leaves of the Camellia Sinensis plant, which are fully oxidised. It is this full oxidation of the tea leaves which distinguishes black tea from other types of tea, such as oolong, green tea and white tea. The black tea particles used for the present invention may comprise black tea from a single tea variety, or from a blend of different tea varieties.

[0029] As used herein, the term “apple fibre particles” encompasses particles derived from the dried solids portion of an apple fruit. Apple fibres are a by-product of the apple juice production process and include material from the skin and seeds of the apple.

[0030] As used herein, the term “rosehip seed particles” encompasses particles derived from the dried seeds of a rose hip, also known as rose haw or rose hep, which is the fruit of the rose plant. A rose plant is a flowering plant of the genus Rosa in the family Rosacae.

[0031] As used herein, the term “lemon balm stem particles” encompasses particles derived from the dried stems of leaves from the lemon balm plant (Melissa officinalis).

[0032] The total content of the non-tobacco plant particles in the homogenised plant material is at least 50 percent by weight on a dry weight basis. Preferably, the total content of the non-tobacco plant particles in the homogenised plant material is at least 55 percent by weight on a dry weight basis. More preferably, the total content of non-tobacco plant particles in the homogenised plant material is at least 60 percent by weight on a dry weight basis.

[0033] The total content of non-tobacco plant particles in the homogenised plant material is preferably less than or equal to 75 percent by weight on a dry weight basis. More preferably, the total content of non-tobacco plant particles in the homogenised plant material is less than or equal to 70 percent by weight on a dry weight basis. More preferably, the total content of non-tobacco plant particles in the homogenised plant material is less than or equal to 65 percent by weight on a dry weight basis.

[0034] For example, the total content of non-tobacco plant particles in the homogenised plant material may be between 50 percent and 75 percent by weight, or between 55 percent and 75 percent by weight, or between 60 percent and 55 percent by weight, on a dry weight basis.

[0035] For example, the total content of non-tobacco plant particles in the homogenised plant material may be between 50 percent and 70 percent by weight, or between 55 percent and 70 percent by weight, or between 60 percent and 50 percent by weight, on a dry weight basis.

[0036] For example, the total content of non-tobacco plant particles in the homogenised plant material may be between 50 percent and 65 percent by weight, or between 55 percent and 65 percent by weight, or between 60 percent and 65 percent by weight, on a dry weight basis.

[0037] The particle size of the non-tobacco plant particles may be adapted depending on the desired properties of the homogenised plant material.

[0038] Particle sizes herein are stated as D-values, whereby the D-value refers to the percentage of particles by number with a diameter of less than or equal to the given D-value. For instance, in a D90 particle size distribution, 90 percent of the particles by number are of a diameter less than or equal to the given D90 value, and 10% percent of the particles by number are of a diameter measuring greater than the given D90 value. The particle size distribution may be determined by laser diffraction. For example, the particle size distribution may be determined by laser diffraction using a Malvern Mastersizer 3000 laser diffraction particle size analyser in accordance with the manufacturer’s instructions.

[0039] The non-tobacco plant particles preferably have a D90 value of at least 20 microns, more preferably at least 30 microns, more preferably at least 40 microns, more preferably at least 50 microns, more preferably at least 60 microns.

[0040] According to the invention, the non-tobacco plant particles have a D90 value of less than or equal to 150 microns, more preferably less than or equal to 120 microns, more preferably less than or equal to 100 microns, more preferably less than or equal to 80 microns.

[0041] For example, the non-tobacco plant particles may have a D90 values of between 20 microns and 150 microns, or between 20 microns and 120 microns, or between 20 microns and 100 microns, or between 20 microns and 80 microns, or between 30 microns and 150 microns, or between 30 microns and 120 microns, or between 30 microns and 100 microns, or between 30 microns and 80 microns or between 40 microns and 150 microns, or between 40 microns and 120 microns, or between 40 microns and 100 microns, or between 40 microns and 80 microns, or between 50 microns and 150 microns, or between 50 microns and 120 microns, or between 50 microns and 100 microns, or between 50 microns and 80 microns, or between 60 microns and 150 microns, or between 60 microns and 120 microns, or between 60 microns and 100 microns, or between 60 microns and 80 microns. The diameter of 100 percent of the non-tobacco plant particles may be less than or equal to 300 microns, more preferably less than or equal to 250 microns.

[0042] The particle size range of the non-tobacco plant particles enables these non-tobacco plant particles to be used in existing cast leaf processes, in place of tobacco particles.

[0043] The homogenised plant material may optionally comprise tobacco particles in addition to the non-tobacco plant particles defined above. However, preferably the level of tobacco particles is relatively low. Preferably, the homogenised plant material comprises less than 5 percent by weight of tobacco particles, on a dry weight basis. More preferably, the homogenised plant material comprises less than 2 percent by weight of tobacco particles, on a dry weight basis. More preferably, the homogenised plant material comprises less than 1 percent by weight of tobacco particles, on a dry weight basis.

[0044] In some preferred embodiments of the present invention, the homogenised plant material is substantially free from tobacco, or free from tobacco.

[0045] According to the invention, the homogenised plant material comprises at least 10 percent by weight of aerosol former, on a dry weight basis. The homogenised plant material may comprise one or more aerosol formers. Suitable aerosol formers for inclusion in the homogenised plant material are known in the art and include, but are not limited to: polyhydric alcohols, such as triethylene glycol, propylene glycol, 1 ,3-butanediol and glycerol; esters of polyhydric alcohols, such as glycerol mono-, di- or triacetate; and aliphatic esters of mono-, di- or polycarboxylic acids, such as dimethyl dodecanedioate and dimethyl tetradecanedioate. Preferably, the aerosol former comprises one or more of glycerol and propylene glycol. The aerosol former may consist of glycerol or propylene glycol or of a combination of glycerol and propylene glycol.

[0046] Preferably, the homogenised plant material has an aerosol former content of at least 12 percent by weight on a dry weight basis. More preferably, the homogenised plant material has an aerosol former content of at least 15 percent by weight on a dry weight basis.

[0047] The homogenised plant material preferably has an aerosol former content of less than or equal to 35 percent by weight on a dry weight basis. More preferably, the homogenised plant material has an aerosol former content of less than or equal to 30 percent by weight on a dry weight basis. More preferably, the homogenised plant material has an aerosol former content of less than or equal to 25 percent by weight on a dry weight basis. More preferably, the homogenised plant material has an aerosol former content of less than or equal to 20 percent by weight on a dry weight basis.

[0048] For example, the aerosol former content of the homogenised plant material is preferably between 10 percent and 35 percent by weight, or between 12 percent and 35 percent by weight, or between 15 percent and 35 percent by weight. For example, the aerosol former content of the homogenised plant material is preferably between 10 percent and 30 percent by weight, or between 12 percent and 30 percent by weight, or between 15 percent and 30 percent by weight.

[0049] For example, the aerosol former content of the homogenised plant material is preferably between 10 percent and 25 percent by weight, or between 12 percent and 25 percent by weight, or between 15 percent and 25 percent by weight.

[0050] For example, the aerosol former content of the homogenised plant material is preferably between 10 percent and 20 percent by weight, or between 12 percent and 20 percent by weight, or between 15 percent and 20 percent by weight.

[0051] Preferably, the homogenised plant material comprises glycerol as an aerosol former. For example, the homogenised plant material may comprise between 10 percent and 35 percent by weight of glycerol, or between 12 percent and 30 percent by weight of glycerol, or between 15 percent and 25 percent by weight of glycerol, or between 15 percent and 20 percent by weight of glycerol, on a dry weight basis.

[0052] Preferably, the weight ratio of non-tobacco plant particles to aerosol former in the homogenised plant material is at least 1.5, more preferably at least 2, more preferably at least 2.5. The weight ratio of non-tobacco plant particles to aerosol former may be less than or equal to 5, preferably less than or equal to 4.5.

[0053] According to the invention, the homogenised plant material comprises at least 2 percent by weight of exogenous binder, on a dry weight basis. The inclusion of binder helps to agglomerate the non-tobacco plant particles. The term “exogenous binder” refers to binder material that is added to the homogenised plant material as a distinct component from any binder that is intrinsically present in the non-tobacco plant particles or tobacco particles (where present).

[0054] Suitable exogenous binders for inclusion in the homogenised plant material as described herein are known in the art and include, but are not limited to: gums such as, for example, guar gum, xanthan gum, arabic gum and locust bean gum; cellulosic binders such as, for example, hydroxypropyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, methyl cellulose and ethyl cellulose; polysaccharides such as, for example, starches, organic acids, such as alginic acid, conjugate base salts of organic acids, such as sodium-alginate, agar and pectins; and combinations thereof. Preferably, the binder comprises guar gum, carboxymethyl cellulose (CMC) or a combination thereof.

[0055] Preferably, the homogenised plant material comprises at least 2.5 percent by weight of exogenous binder, more preferably at least 3 percent by weight of exogenous binder, on a dry weight basis.

[0056] Preferably, the homogenised plant material comprises less than or equal to 10 percent by weight of exogenous binder, more preferably less than or equal to 7.5 percent by weight of exogenous binder, more preferably less than or equal to 5 percent by weight of exogenous binder, on a dry weight basis.

[0057] For example, the homogenised plant material may comprise between 2 percent by weight and 10 percent by weight of exogenous binder, or between 2.5 percent by weight and 10 percent by weight of exogenous binder, or between 3 percent by weight and 10 percent by weight of exogenous binder, on a dry weight basis.

[0058] For example, the homogenised plant material may comprise between 2 percent by weight and 7.5 percent by weight of exogenous binder, or between 2.5 percent by weight and 7.5 percent by weight of exogenous binder, or between 3 percent by weight and 7.5 percent by weight of exogenous binder, on a dry weight basis.

[0059] For example, the homogenised plant material may comprise between 2 percent by weight and 5 percent by weight of exogenous binder, or between 2.5 percent by weight and 5 percent by weight of exogenous binder, or between 3 percent by weight and 5 percent by weight of exogenous binder, on a dry weight basis.

[0060] According to the invention, the homogenised plant material comprises at least 2 percent by weight of additional fibres, on a dry weight basis. The inclusion of additional fibres helps to optimise the mechanical properties of the homogenised plant material, for example, to improve the tensile strength. The term “additional fibres” refers to exogenous fibres that are added to the homogenised plant material as a distinct component from any fibres that are intrinsically present in the non-tobacco plant particles or tobacco particles (where present).

[0061] Suitable exogenous fibres for inclusion in the homogenised plant material are known in the art and include but are not limited to: cellulose fibres; soft-wood fibres; hard-wood fibres; jute fibres and combinations thereof. Preferably, the additional fibres comprise cellulose fibres.

[0062] Prior to inclusion in the homogenised plant material, fibres may be treated by suitable processes known in the art including, but not limited to: mechanical pulping; refining; chemical pulping; bleaching; sulfate pulping; and combinations thereof. A fibre typically has a length greater than its width.

[0063] Suitable fibres typically have lengths of greater than 400 micrometres and less than or equal to 4 mm, preferably within the range of 0.7 mm to 4 mm.

[0064] Preferably, the homogenised plant material comprises at least 3 percent by weight of additional fibres, more preferably at least 4 percent by weight of additional fibres, on a dry weight basis.

[0065] Preferably, the homogenised plant material comprises less than or equal to 10 percent by weight of additional fibres, more preferably less than or equal to 8 percent by weight of additional fibres, more preferably less than or equal to 6 percent by weight of additional fibres, on a dry weight basis. For example, the homogenised plant material may comprise between 2 percent by weight and 10 percent by weight of additional fibres, or between 3 percent by weight and 10 percent by weight of additional fibres, or between 4 percent by weight and 10 percent by weight of additional fibres, on a dry weight basis.

[0066] For example, the homogenised plant material may comprise between 2 percent by weight and 8 percent by weight of additional fibres, or between 3 percent by weight and 8 percent by weight of additional fibres, or between 4 percent by weight and 8 percent by weight of additional fibres, on a dry weight basis.

[0067] For example, the homogenised plant material may comprise between 2 percent by weight and 6 percent by weight of additional fibres, or between 3 percent by weight and 6 percent by weight of additional fibres, or between 4 percent by weight and 6 percent by weight of additional fibres, on a dry weight basis.

[0068] Preferably, the weight ratio of the additional fibres to the exogenous binder in the homogenised plant material is at least 1 , more preferably at least 1.25, more preferably at least 1 .5. The weight ratio of the additional fibres to the exogenous binder may be less than or equal to 2.5, preferably less than or equal to 2.

[0069] According to the present invention, the homogenised plant material further comprises at least 0.5 percent by weight of an active agent, on a dry weight basis. As used herein, the term “active agent” refers to an agent which elicits a physiological effect in the consumer following inhalation of the aerosol generated from the aerosol-generating substrate incorporating the active agent. Suitable active agents for use in aerosol-generating substrates would be known to the skilled person.

[0070] Preferably, the homogenised plant material comprises at least 1 percent by weight of an active agent, more preferably at least 1 .25 percent by weight of an active agent, more preferably at least 1 .5 percent by weight of an active agent, on a dry weight basis.

[0071] Preferably, the homogenised plant material comprises less than or equal to 10 percent by weight of an active agent, more preferably less than or equal to 8 percent by weight of an active agent, more preferably less than or equal to 5 percent by weight of an active agent.

[0072] For example, the homogenised plant material may comprise between 0.5 percent by weight and 10 percent by weight of an active agent, or between 1 percent by weight and 10 percent by weight of an active agent, or between 1.25 percent by weight and 10 percent by weight of an active agent, or between 1.5 percent by weight and 10 percent by weight of an active agent, on a dry weight basis.

[0073] For example, the homogenised plant material may comprise between 0.5 percent by weight and 8 percent by weight of an active agent, or between 1 percent by weight and 8 percent by weight of an active agent, or between 1 .25 percent by weight and 8 percent by weight of an active agent, or between 1 .5 percent by weight and 8 percent by weight of an active agent, on a dry weight basis.

[0074] For example, the homogenised plant material may comprise between 0.5 percent by weight and 5 percent by weight of an active agent, or between 1 percent by weight and 5 percent by weight of an active agent, or between 1 .25 percent by weight and 5 percent by weight of an active agent, or between 1 .5 percent by weight and 5 percent by weight of an active agent, on a dry weight basis.

[0075] Preferably, the active agent comprises nicotine. As used herein with reference to the invention, the term “nicotine” encompasses nicotine, a nicotine base or a nicotine salt. In embodiments in which the aerosol-generating substrate comprise a nicotine base or a nicotine salt, the amounts of nicotine recited herein are the amount of free base nicotine or amount of protonated nicotine, respectively.

[0076] The aerosol-generating substrate may comprise natural nicotine or synthetic nicotine.

[0077] The homogenised plant material may have a nicotine content of at least 0.5 percent by weight, preferably at least 1 percent by weight, preferably at least 1 .25 percent by weight, more preferably at least 1 .5 percent by weight, on a dry weight basis.

[0078] The homogenised plant material may have a nicotine content of less than or equal to 10 percent by weight, preferably less than or equal to 8 percent by weight, more preferably less than or equal to 5 percent by weight, more preferably less than or equal to 2.5 percent by weight, on a dry weight basis.

[0079] For example, the homogenised plant material may comprise between 0.5 percent by weight and 10 percent by weight of nicotine, or between 1 percent by weight and 10 percent by weight of nicotine, or between 1.25 percent by weight and 10 percent by weight of nicotine, or between 1 .5 percent by weight and 10 percent by weight of nicotine, on a dry weight basis.

[0080] For example, the homogenised plant material may comprise between 0.5 percent by weight and 8 percent by weight of nicotine, or between 1 percent by weight and 8 percent by weight of nicotine, or between 1.25 percent by weight and 8 percent by weight of nicotine, or between 1.5 percent by weight and 8 percent by weight of nicotine, on a dry weight basis.

[0081] For example, the homogenised plant material may comprise between 0.5 percent by weight and 5 percent by weight of nicotine, or between 1 percent by weight and 5 percent by weight of nicotine, or between 1.25 percent by weight and 5 percent by weight of nicotine, or between 1.5 percent by weight and 5 percent by weight of nicotine, on a dry weight basis.

[0082] For example, the homogenised plant material may comprise between 0.5 percent by weight and 2.5 percent by weight of nicotine, or between 1 percent by weight and 2.5 percent by weight of nicotine, or between 1.25 percent by weight and 2.5 percent by weight of nicotine, or between 1 .5 percent by weight and 2.5 percent by weight of nicotine, on a dry weight basis. Alternatively or in addition, the homogenised plant material may comprise one or more cannabinoid compounds selected from the group consisting of: tetrahydrocannabinol (THC), tetrahydrocannabinolic acid (THCA), cannabidiol (CBD), cannabidiolic acid (CBDA), cannabinol (CBN), cannabigerol (CBG), cannabigerol monomethyl ether (CBGM), cannabivarin (CBV), cannabidivarin (CBDV), tetrahydrocannabivarin (THCV), cannabichromene (CBC), cannabicyclol (CBL), cannabichromevarin (CBCV), cannabigerovarin (CBGV), cannabielsoin (CBE), cannabicitran (CBT) and combinations thereof. Preferably, the one or more cannabinoid compounds are selected from CBD, THC and a combination thereof. Particularly preferably, the one or more cannabinoid compounds includes CBD.

[0083] In addition to the active agent, the homogenised plant material may further comprise one or more flavourants. The inclusion of one or more flavourants may be advantageous in order to provide a desired level of flavourant, in view of the relatively low sensorial impact of the nontobacco plant particles used in the homogenised plant material.

[0084] Suitable flavourants would be known to the skilled person. The one or more flavourants may comprise one or more of: one or more essential oils such as eugenol, peppermint oil and spearmint oil; one or both of menthol and eugenol; one or both of anethole and linalool.

[0085] The homogenised plant material may have a flavourant content of at least 0.5 percent by weight, preferably at least 1 percent by weight, more preferably at least 2 percent by weight, on a dry weight basis.

[0086] The homogenised plant material may have a flavourant content of less than or equal to 10 percent by weight, preferably less than or equal to 8 percent by weight, more preferably less than or equal to 5 percent by weight, on a dry weight basis.

[0087] For example, the homogenised plant material may have a flavourant content of between 0.5 percent and 10 percent by weight, or between 1 percent and 8 percent by weight, or between 2 percent and 5 percent by weight, on a dry weight basis.

[0088] Alternatively or in addition, the homogenised plant material of aerosol-generating substrates according to the present invention may further comprise an acidic pH modifier. The inclusion of an acidic pH modifier may be particularly advantageous in embodiments in which the homogenised plant material comprises nicotine as the active agent. The acidic pH modifier is included in order to decrease the pH of the homogenised plant material, which has been advantageously found to improve the efficiency of nicotine delivery from the aerosol-generating substrate.

[0089] Some of the non-tobacco plant materials used to form the non-tobacco plant particles of the present invention, produce a slurry with a relatively high pH level. For example, this is true for slurries formed from lemon balm stem particles or rosehip seed particles. It has been found that this higher pH can lead to a higher volatility of nicotine in the slurry, so that a greater proportion of the nicotine is lost during drying of the cast sheet. The inclusion of an acidic pH modifier can advantageously reduce the pH to a sufficient level that the nicotine losses during production are minimised. In this way, the nicotine can be efficiently retained within the aerosol-generating substrate and delivered to the consumer upon heating. Inclusion of the acidic pH modifier in the homogenised plant material decreases the pH of the homogenised plant material by a measurable amount.

[0090] Preferably, inclusion of the acidic pH modifier decreases the pH of the homogenised plant material by at least 0.5 compared to the pH of a similar homogenised plant material that does not include the acidic pH modifier. The level of pH adjustment required for a homogenised plant material will depend upon the nature of the non-tobacco plant particles that are used, since some plants will produce a slurry with a significantly higher pH than others. For example, it has been found that for some non-tobacco plant particles, a greater level of pH adjustment is required than for other non-tobacco plant particles. The type of acidic pH modifier and the amount of acidic pH modifier that is used can be adapted according to the level of pH adjustment that is required.

[0091] Preferably, the acidic pH modifier comprises an acid. More preferably, the acidic pH modifier comprises one or more carboxylic acids. Suitable carboxylic acids for use as the acidic pH modifier include but are not limited to: fumaric acid, maleic acid, malic acid, adipic acid, succinic acid, lactic acid, levulinic acid, acetic acid, benzoic acid, citric acid.

[0092] In particularly preferred embodiments, the acidic pH modifier comprises at least one of lactic acid and levulinic acid.

[0093] According to the present invention, the homogenised plant material comprises at least 1 percent by weight of the acidic pH modifier, on a dry weight basis. Preferably, the homogenised plant material comprises at least 1.05 percent by weight of the acidic pH modifier, more preferably at least 1 .1 percent by weight of the acidic pH modifier, on a dry weight basis.

[0094] Preferably, the homogenised plant material comprises less than or equal to 2 percent by weight of the acidic pH modifier, more preferably less than or equal to 1 .75 percent by weight of the acidic pH modifier, more preferably less than 1 .5 percent by weight of the acidic pH modifier, on a dry weight basis.

[0095] For example, the homogenised plant material may comprise between 1 percent by weight and 2 percent by weight of the acidic pH modifier, or between 1.05 percent by weight and 1.75 percent by weight of the acidic pH modifier, or between 1.1 percent by weight and 1.5 percent by weight of the acidic pH modifier, on a dry weight basis.

[0096] Preferably, the homogenised plant material has a pH less than or equal to 6. More preferably, the homogenised plant material has a pH less than or equal to 5.5.

[0097] Preferably, the homogenised plant material has a pH of at least 4. For example, the pH of the homogenised plant material may be between 4 and 6, or between 4 and 5.5. The pH of the homogenised plant material is measured by dispersing a 0.5 g sample of the homogenised plant material in 5 grams of water, agitating the dispersion and then measuring the pH of the dispersion using a pH electrode.

[0098] Alternatively or in addition, the homogenised plant material of aerosol-generating substrates according to the present invention may further comprise a filler, preferably an inert filler which does not significantly contribute to the sensorial properties of the aerosol generated from the aerosol-generating substrate upon heating. The inclusion of a filler may advantageously optimise the viscosity of the slurry made during production of the homogenised plant material and the machineability of the resultant homogenised plant material.

[0099] Suitable fillers would be known to the skilled person and include but are not limited to: cellulose powder, microcrystalline cellulose (MCC), maltodextrin, or combinations thereof.

[0100] The homogenised plant material may comprise at least 1 percent by weight of a filler, preferably at least 2 percent by weight of a filler, more preferably at least 3 percent by weight of a filler, on a dry weight basis.

[0101] The homogenised plant material may comprise less than or equal to 10 percent by weight of a filler, preferably less than or equal to 8 percent by weight of a filler, preferably less than or equal to 5 percent by weight of a filler, on a dry weight basis.

[0102] For example, the homogenised plant material may comprise between 1 percent by weight and 10 percent by weight of filler, or between 2 percent by weight and 8 percent by weight of filler, or between 3 percent by weight and 5 percent by weight of filler, on a dry weight basis.

[0103] The homogenised plant material used in articles and substrates according to the invention may be produced by various processes including paper making, casting, dough reconstitution, extrusion or any other suitable process.

[0104] Some processes such as casting and paper making are more suitable for producing homogenised plant material in sheet form. The term “cast leaf” is used herein to refer to a product made by a casting process that is based on casting a slurry comprising non-tobacco plant particles (for example, the non-tobacco plant particles), aerosol former (for example, glycerol) and any other components of the homogenised plant material onto a supportive surface, such as a belt conveyor, drying the slurry and removing the dried sheet from the supportive surface. An example of the casting or cast leaf process is described in, for example, US-A-5,724,998 for making cast leaf tobacco. In a cast leaf process, particulate plant materials are produced by pulverizing, grinding, or comminuting parts of the plant.

[0105] Preferably, the homogenised plant material used in articles and substrates according to the present invention may be produced by casting, that is to say, it may be in the form of cast leaf.

[0106] In methods according to the present invention, as defined above, the non-tobacco plant particles are mixed with a liquid component, typically water, to form a slurry. Other components are added to the slurry, including the aerosol former, exogenous binder, additional fibres, active agent and other optional components as described above.

[0107] The slurry is cast in the form of a sheet onto a supportive surface and dried into a sheet of homogenised plant material. Preferably, the drying takes place at between 80 and 160 degrees Celsius. Such methods are used to produce homogenised plant material in the form of cast leaf.

[0108] An alternative paper-making process for producing sheets of homogenised plant material comprises a first step of mixing a plant material and water to form a dilute suspension comprising mostly separate cellulose fibres. This first step may involve soaking and applying heat. The suspension has a lower viscosity and a higher water content than the slurry produced in the casting process. The suspension may then be separated into an insoluble portion containing solid fibrous components and a liquid or aqueous portion comprising soluble plant substances. The water remaining in the insoluble fibrous portion may be drained through a screen, acting as a sieve, such that a web of randomly interwoven fibres may be laid down. Water may be further removed from this web by pressing with rollers, sometimes aided by suction or vacuum. When most of the moisture has been removed, a generally flat, uniform sheet of plant fibres is achieved. The soluble plant substances that were removed from the sheet may be concentrated, and the concentrated plant substances may be added back to the sheet resulting in a sheet of homogenised plant material. This process, as described in US 3,860,012, has been used with tobacco to make reconstituted tobacco products, also known as tobacco paper.

[0109] Other known processes that can be applied to producing homogenised plant materials are dough reconstitution processes of the type described in, for example, US-A-3,894,544; and extrusion processes of the type described in, for example, in GB-A-983,928. Typically, the densities of homogenised plant materials produced by extrusion processes and dough reconstitution processes are greater than the densities of the homogenised plant materials produced by casting processes.

[0110] Preferably, the aerosol-generating substrate is in the form of one or more sheets of homogenised plant material.

[0111] The one or more sheets as described herein may each individually have a thickness of between 100 microns and 600 microns, preferably between 150 microns and 500 microns, preferably between 200 microns and 400 microns, and most preferably between 250 microns and 350 microns. Individual thickness refers to the thickness of the individual sheet, whereas combined thickness refers to the total thickness of all sheets that make up the aerosol-generating substrate. For example, if the aerosol-generating substrate is formed from two individual sheets, then the combined thickness is the sum of the thickness of the two individual sheets or the measured thickness of the two sheets where they are stacked in the aerosol-generating substrate.

[0112] The one or more sheets as described herein may each have an average thickness of between 100 microns and 600 microns, preferably between 150 microns and 500 microns, preferably between 200 microns and 400 microns, and most preferably between 250 microns and

[0113] 350 microns.

[0114] The one or more sheets as described herein may each individually have a grammage of between 100 grams per square metre and 300 grams per square metre, or between 150 grams per square meter metre and 250 grams per square metre, or between 150 grams per square meter and 200 grams per square metre.

[0115] The one or more sheets as described herein may each individually have a density of from 0.3 grams per cubic centimetre to 1.3 grams per cubic centimetre, preferably from 0.4 grams per cubic centimetre to 1.0 grams per cubic centimetre and more preferably from 0.5 grams per cubic centimetre to 0.9 grams per cubic centimetre.

[0116] The one or more sheets as described herein may each individually have a tensile strength at peak in a cross direction of between 100 N / m and 600 N / m or preferably between 150 N / m and 500 N / m, normalized to a thickness of a single sheet, whereby the thickness of the single sheet ranges from 215 pm to 275 pm.

[0117] The one or more sheets as described herein may each individually have a tensile strength at peak in a machine direction of between 300 N / m and 750 N / m or preferably between 400 N / m and 650 N / m, normalized to a thickness of a single sheet, whereby the thickness of the single sheet ranges from 215 pm to 275 pm.

[0118] The one or more sheets as described herein may each individually have a total fracture strain in a cross direction of between 2 percent and 8 percent or preferably between 4 percent and 6 percent.

[0119] The one or more sheets as described herein may each individually have a total fracture strain in a machine direction of between 4 percent and 10 percent or preferably between 6 percent and 8 percent.

[0120] The machine direction refers to the direction in which the sheet material would be rolled onto or unrolled from a bobbin and fed into a machine, while the cross direction is perpendicular to the machine direction. Such values of tensile strength make sheets and methods described herein particularly suitable for subsequent operations involving mechanical stresses.

[0121] The tensile strength at peak and the total fracture strain of a sheet of homogenised plant material may be measured using a Universal Tensile / Compression Testing Machine, such as an Instron 5944 or equivalent with a tension load cell of 100N. The sheet of homogenised plant material is conditioned for at least 48 hours at 22 degrees Celsius and 50 percent RH before testing. A sample of the sheet of homogenised plant material having dimensions of 25 millimetres by 50 millimetres is punched from the sheet and mounted in two pneumatic action grips, aligned in the direction being tested. The testing machine is then used to stretch the sample to breakage at a constant rate of elongation. The tensile strength at peak (calculated as the force at fracture divided by the width of the sheet) and the total fracture strain (corresponding to the maximum elongation of the sheet expressed as a percentage) of the sample are measured by the testing machine.

[0122] The provision of a sheet having the levels of thickness, grammage and tensile strength as defined above advantageously optimises the machinability of the sheet to form the aerosolgenerating substrate and ensures that damage, such as tearing of the sheet, is avoided during high speed processing of the sheet.

[0123] Preferably the one or more sheets may be in the form of one or more gathered sheets. Preferably the aerosol-generating substrate is in the form of a rod comprising one or more gathered sheets of the homogenised plant material, circumscribed by a wrapper.

[0124] The sheets of homogenised plant material may preferably be gathered transversely relative to the longitudinal axis thereof and circumscribed with a wrapper to form a continuous rod or a plug. The continuous rod may be severed into a plurality of discrete rods or plugs. The wrapper may be a paper wrapper or a non-paper wrapper. Suitable paper wrappers for use in specific embodiments of the invention are known in the art and include, but are not limited to: cigarette papers; and filter plug wraps.

[0125] The sheets of homogenised plant material may be textured through crimping, embossing, perforating or otherwise texturing prior to gathering or being cut into shreds. Preferably the sheets of homogenised plant material are crimped prior to gathering, such that the homogenised plant material may be in the form of a crimped sheet, more preferably in the form of a gathered crimped sheet. As used herein, the term “crimped sheet” denotes a sheet having a plurality of substantially parallel ridges or corrugations.

[0126] Alternatively, the homogenised plant material may be in the form of a plurality of shreds, strands or strips. The shreds, strands or strips may be used to form a plug. In such embodiments, the aerosol-generating substrate therefore comprises shredded homogenised plant material.

[0127] In some embodiments, the strands may be formed in situ within the aerosol-generating substrate as a result of the splitting or cracking of a sheet of homogenised plant material during formation of the aerosol-generating substrate, for example, as a result of crimping. The strands of homogenised plant material within the aerosol-generating substrate may be separate from each other. Alternatively, each strand of homogenised plant material within the aerosolgenerating substrate may be at least partially connected to an adjacent strand or strands along the length of the strands. For example, adjacent strands may be connected by one or more fibres. This may occur, for example, where the strands have been formed due to the splitting of a sheet of homogenised plant material during production of the aerosol-generating substrate, as described above.

[0128] Typically, the width of such shreds, strands or strips is about 5 millimetres, or about 4 millimetres, or about 3 millimetres, or about 2 millimetres or less. The length of the shreds, strands or strips may be greater than about 5 millimetres, between about 5 millimetres to about 15 millimetres, about 8 millimetres to about 12 millimetres, or about 12 millimetres.

[0129] The plurality of strands preferably extend substantially longitudinally along the length of the aerosol-generating substrate, aligned with the longitudinal axis. Preferably, the plurality of strands are therefore aligned substantially parallel to each other. This provides a relatively uniform, regular structure which facilitates the insertion of an internal heater element into the aerosolgenerating substrate and optimises the efficiency of heating.

[0130] The aerosol-generating substrate of aerosol-generating articles according to the present invention is formed of the homogenised plant material described above. Preferably, the aerosolgenerating articles of the present invention comprise an aerosol-generating substrate in the form of a rod of homogenised plant material circumscribed by a wrapper.

[0131] The aerosol-generating substrate may have a density of less than or equal to 1000 milligrams per cubic centimetre. Preferably, the aerosol-generating substrate may have a density of less than or equal to 900 milligrams per cubic centimetre. More preferably, the aerosolgenerating substrate may have a density of less than or equal to 800 milligrams per cubic centimetre.

[0132] Preferably, the aerosol-generating substrate may have a density of at least 200 milligrams per cubic centimetre. More preferably, the aerosol-generating substrate may have a density of at least 300 milligrams per cubic centimetre. More preferably, the aerosol-generating substrate may have a density of at least 400 milligrams per cubic centimetre. More preferably, the aerosolgenerating substrate may have a density of at least 500 milligrams per cubic centimetre.

[0133] For example, the aerosol-generating substrate preferably has a density of between 200 milligrams per cubic centimetre and 1000 milligrams per cubic centimetre, or between 300 milligrams per cubic centimetre and 950 milligrams per cubic centimetre, or between 400 milligrams per cubic centimetre and 900 milligrams per cubic centimetre, or between 500 milligrams per cubic centimetre and 800 milligrams per cubic centimetre, or between 700 milligrams per cubic centimetre and 800 milligrams per cubic centimetre.

[0134] The term “density” as used herein in relation to the aerosol-generating substrate refers to the bulk density of the aerosol-generating substrate. This can be calculated by measuring the total weight of the aerosol-generating substrate and dividing this by the volume of the rod of aerosol-generating substrate (excluding any wrapper).

[0135] The rod of aerosol-generating substrate preferably comprises at least 1000 milligrams of homogenised plant material, more preferably at least 1500 milligrams of homogenised plant material, more preferably at least 2000 milligrams of homogenised plant material.

[0136] Preferably, the rod of aerosol-generating substrate comprises up to 3500 milligrams of homogenised plant material, more preferably up to 3250 milligrams of homogenised plant material, more preferably up to 3000 milligrams of homogenised plant material. For example, the rod of aerosol-generating substrate may comprise between 1000 milligrams and 3500 milligrams of homogenised plant material, or between 1500 milligrams and 3250 milligrams of homogenised plant material, or between 2000 milligrams and 3000 milligrams of homogenised plant material.

[0137] In some preferred embodiments, the rod of aerosol-forming substrate further comprises a heating element arranged to heat the homogenised plant material. The heating element may be one or more susceptor elements. The aerosol-generating substrate may comprise one or more elongate susceptor elements.

[0138] In some preferred embodiments, the rod of aerosol-generating substrate has a length of less than or equal to 20 millimetres. More preferably, the rod of aerosol-generating substrate has a length of less than or equal to 18 millimetres. More preferably, the rod of aerosol-generating substrate has a length of less than or equal to 15 millimetres. More preferably, the rod of aerosol generating substrate has a length of less than or equal to 14 millimetres. More preferably, the rod of aerosol-generating substrate has a length of less or equal to than 13 millimetres.

[0139] Preferably, the rod of aerosol-generating substrate has a length of at least 6 millimetres. More preferably, the rod of aerosol-generating substrate has a length of at least 10 millimetres.

[0140] For example, the rod of aerosol-generating substrate has a length of between 6 millimetres and 20 millimetres, or between 6 millimetres and 18 millimetres, or between 6 millimetres and 15 millimetres, or between 6 millimetres and 14 millimetres, or between 6 millimetres and 13 millimetres, or between 10 millimetres and 18 millimetres, or between 10 millimetres and 15 millimetres, or between 10 millimetres and 14 millimetres, or between 10 millimetres and 13 millimetres.

[0141] In some preferred embodiments, a ratio of the length of the rod of aerosol-generating substrate to the length of the aerosol-generating article is less than 0.4. More preferably, the ratio of the length of the rod of aerosol-generating substrate to the length of the aerosol-generating article is less than 0.35. More preferably, the ratio of the length of the rod of aerosol-generating substrate to the length of the aerosol-generating article is less than 0.3. Preferably, the ratio of the length of the rod of aerosol-generating substrate to the length of the aerosol-generating article is at least 0.15. More preferably, the ratio of the length of the rod of aerosol-generating substrate to the length of the aerosol-generating article is at least 0.2. More preferably, the ratio of the length of the rod of aerosol-generating substrate to the length of the aerosol-generating article is at least 0.25. More preferably, the ratio of the length of the rod of aerosol-generating substrate to the length of the aerosol-generating article is at least 0.3.

[0142] For example, the ratio of the length of the rod of aerosol-generating substrate to the length of the aerosol-generating article may be between 0.15 and 0.4, or between 0.2 and 0.35, or between 0.25 and 0.3, or between 0.3 and 0.4.

[0143] The rod of aerosol-generating substrate preferably has an external diameter that is approximately equal to the external diameter of the aerosol-generating article.

[0144] The “external diameter of the rod of aerosol-generating substrate” may be calculated as the average of a plurality of measurements of the diameter of the rod of aerosol-generating substrate taken at different locations along the length of the rod of aerosol-generating substrate.

[0145] Preferably, the rod of aerosol-generating substrate has an external diameter of at least about 5 millimetres. More preferably, the rod of aerosol-generating substrate has an external diameter of at least about 6 millimetres. Even more preferably, the rod of aerosol-generating substrate has an external diameter of at least about 7 millimetres.

[0146] The rod of aerosol-generating substrate preferably has an external diameter of less than or equal to about 12 millimetres. More preferably, the rod of aerosol-generating substrate has an external diameter of less than or equal to about 10 millimetres. Even more preferably, the rod of aerosol-generating substrate has an external diameter of less than or equal to about 8 millimetres.

[0147] In some embodiments, the rod of aerosol-generating substrate has an external diameter from about 5 millimetres to about 12 millimetres, preferably from about 6 millimetres to about 12 millimetres, more preferably from about 7 millimetres to about 12 millimetres. In other embodiments, the rod of aerosol-generating substrate has an external diameter from about 5 millimetres to about 12 millimetres, preferably from about 6 millimetres to about 10 millimetres, more preferably from about 7 millimetres to about 10 millimetres. In further embodiments, the rod of aerosol-generating substrate has an external diameter from about 5 millimetres to about 8 millimetres, preferably from about 6 millimetres to about 8 millimetres, more preferably from about 7 millimetres to about 8 millimetres.

[0148] In particularly preferred embodiments, the rod of aerosol-generating substrate has an external diameter of less than about 7.5 millimetres. By way of example, the rod of aerosolgenerating substrate may an external diameter of about 7.2 millimetres.

[0149] The aerosol-generating article may have any desired shape. For example, the aerosolgenerating article may be substantially cylindrical.

[0150] The aerosol-generating article may have any desired transverse cross-section. For example, the aerosol-generating article may have a substantially circular, oval or elliptical transverse cross-section.

[0151] The aerosol-generating article may have any desired length. For example, the aerosolgenerating article may have a length of between 30 millimetres and 70 millimetres, between 35 millimetres and 65 millimetres, or between 40 millimetres and 60 millimetres.

[0152] The aerosol-generating article may have any desired width. For example, the aerosolgenerating article may have a width of between 5 millimetres and 10 millimetres, between 6 millimetres and 9 millimetres, or between 7 millimetres and 8 millimetres.

[0153] The aerosol-generating article may include one or more additional components. The one or more other components may include one or more of an upstream element, a support element, an aerosol-cooling element and a mouthpiece element.

[0154] The aerosol-generating article may comprise an upstream element located at the distal end of the aerosol-generating article. The upstream element may be located immediately upstream of the aerosol-generating substrate.

[0155] The upstream element may advantageously prevent direct contact with the aerosolgenerating substrate. This may advantageously help to prevent displacement or deformation of the susceptor during transport and handling of the aerosol-generating article.

[0156] The upstream element may comprise a plug of porous material. For example, the upstream element may comprise a cellulose acetate plug.

[0157] The upstream element may have any desired shape. For example, the upstream element may be substantially cylindrical.

[0158] The upstream element may have any desired transverse cross-section. For example, the support element may have a substantially circular, oval or elliptical transverse cross-section.

[0159] The upstream element may have any desired length. For example, the upstream element may have a length of between 1 millimetre and 10 millimetres, between 1 millimetre and 8 millimetres, or between 1 millimetre and 6 millimetres. For example, the upstream element may have a length of between 3 millimetres and 10 millimetres, between 3 millimetres and

[0160] 8 millimetres, or between 3 millimetres and 6 millimetres.

[0161] The upstream element may have any desired width. For example, the upstream element may have a width of between 5 millimetres and 10 millimetres, between 6 millimetres and

[0162] 9 millimetres, or between 7 millimetres and 8 millimetres. The upstream element may have a width that is substantially the same as the width of the aerosol-generating article.

[0163] The aerosol-generating article may comprise a support element located between the aerosol-generating substrate and the proximal end of the aerosol-generating article.

[0164] The support element may be located immediately downstream of the aerosol-generating substrate.

[0165] The support element may comprise a hollow tubular segment. For example, the support element may comprise a hollow cellulose acetate tube. The hollow tubular segment may define a longitudinal cavity providing an unrestricted flow channel.

[0166] The support element may have any desired shape. For example, the support element may be substantially cylindrical.

[0167] The support element may have any desired transverse cross-section. For example, the support element may have a substantially circular, oval or elliptical transverse cross-section.

[0168] The support element may have any desired length. For example, the support element may have a length of between 5 millimetres and 15 millimetres, between 5 millimetres and 12 millimetres, or between 5 millimetres and 10 millimetres. For example, the support element may have a length of between 7 millimetres and 15 millimetres, between 7 millimetres and 12 millimetres, or between 7 millimetres and 10 millimetres.

[0169] The support element may have any desired width. For example, the support element may have a width of between 5 millimetres and 10 millimetres, between 6 millimetres and 9 millimetres, or between 7 millimetres and 8 millimetres. The support element may have a width that is substantially the same as the width of the aerosol-generating article.

[0170] The aerosol-generating article may comprise a mouthpiece element located at the proximal end of the aerosol-generating article.

[0171] The mouthpiece element may comprise a plug of porous material. For example, the mouthpiece element may comprise a cellulose acetate plug.

[0172] The mouthpiece element may comprise a mouth end cavity.

[0173] The mouth end cavity may be defined by a hollow tubular element provided at the proximal end of the mouthpiece element.

[0174] The mouth end cavity may be defined by a wrapper.

[0175] The mouthpiece element may have any desired shape. For example, the mouthpiece element may be substantially cylindrical.

[0176] The mouthpiece element may have any desired transverse cross-section. For example, the mouthpiece element may have a substantially circular, oval or elliptical transverse cross-section.

[0177] The mouthpiece may have any desired length. For example, the mouthpiece element may have a length of between 5 millimetres and 20 millimetres, between 5 millimetres and 15 millimetres, or between 5 millimetres and 10 millimetres. For example, the mouthpiece element may have a length of between 6 millimetres and 20 millimetres, between 6 millimetres and 15 millimetres, or between 6 millimetres and 10 millimetres. For example, the mouthpiece element may have a length of between 7 millimetres and 20 millimetres, between 7 millimetres and 15 millimetres, or between 7 millimetres and 10 millimetres.

[0178] The mouthpiece element may have any desired width. For example, the mouthpiece element may have a width of between 5 millimetres and 10 millimetres, between 6 millimetres and 9 millimetres, or between 7 millimetres and 8 millimetres. The mouthpiece element may have a width that is substantially the same as the width of the aerosol-generating article.

[0179] In preferred embodiments of the present invention, the mouthpiece element comprises one or more aerosol modifying elements. An aerosol-modifying element may provide an aerosolmodifying agent. As used herein, the term aerosol-modifying agent is used to describe any agent that, in use, modifies one or more features or properties of aerosol passing through the filter. Suitable aerosol-modifying agents include, but are not limited to, agents that, in use, impart a taste or aroma to aerosol passing through the mouthpiece element, or agents that, in use, remove flavours from the aerosol passing through the filter. An aerosol-modifying agent may be one or more of moisture or a liquid flavourant. Water or moisture may modify the sensorial experience of the user, for example by moistening the generated aerosol, which may provide a cooling effect on the aerosol and may reduce the perception of harshness experienced by the user. An aerosol-modifying element may be in the form of a flavour-delivery element to deliver one or more liquid flavourants.

[0180] Preferably, the aerosol-modifying element is in the form of one or more breakable capsules containing a liquid flavourant. Preferably, the mouthpiece element of aerosol-generating articles according to the invention comprises one or more breakable capsule containing a liquid flavourant.

[0181] Suitable capsules are described in WO-A-2007 / 010407, WO-A-2013 / 068100 and WO-A- 2014 / 154887.

[0182] The one or more liquid flavourants may comprise any flavour compound or botanical extract suitable for being releasably disposed in liquid form within the flavour-delivery element to enhance the taste of aerosol produced during use of the aerosol-generating article. The flavourants, liquid or solid, can also be disposed directly in the material which forms the mouthpiece element, such as cellulose acetate tow.

[0183] Suitable flavours or flavourings include, but are not limited to, menthol, mint, such as peppermint and spearmint, chocolate, liquorice, citrus and other fruit flavours, gamma octalactone, vanillin, ethyl vanillin, breath freshener flavours, spice flavours such as cinnamon, methyl salicylate, linalool, eugenol, bergamot oil, geranium oil, lemon oil, cannabis oil, and tobacco flavour. Other suitable flavours may include flavour compounds selected from the group consisting of an acid, an alcohol, an ester, an aldehyde, a ketone, a pyrazine, combinations or blends thereof and the like.

[0184] An aerosol-modifying agent may be an adsorbent material such as activated carbon, which removes certain constituents of the aerosol passing through the mouthpiece element and thereby modifies the flavour and aroma of the aerosol.

[0185] The aerosol-generating article may comprise an aerosol-cooling element located between the aerosol-generating substrate and the proximal end of the aerosol-generating article.

[0186] Where the aerosol-generating article comprises a mouthpiece element, the aerosol-cooling element may be located immediately upstream of the mouthpiece element.

[0187] Where the aerosol-generating article comprises a support element, the aerosol-cooling element may be located immediately downstream of the support element.

[0188] The aerosol-cooling element may comprise a hollow tubular segment. For example, the aerosol-cooling element may comprise a hollow cellulose acetate tube.

[0189] The hollow tubular segment may define a longitudinal cavity providing an unrestricted flow channel. The aerosol-cooling element may have any desired shape. For example, the mouthpiece element may be substantially cylindrical.

[0190] The aerosol-cooling element may have any desired transverse cross-section. For example, the aerosol-cooling element may have a substantially circular, oval or elliptical transverse crosssection.

[0191] The aerosol-cooling element may have any desired length. For example, the aerosolcooling element may have a length of between 5 millimetres and 20 millimetres or between 5 millimetres and 15 millimetres. For example, the aerosol-cooling element may have a length of between 6 millimetres and 20 millimetres or between 6 millimetres and 15 millimetres. For example, the aerosol-cooling element may have a length of between 7 millimetres and 20 millimetres or between 7 millimetres and 15 millimetres.

[0192] The aerosol-cooling element may have any desired width. For example, the aerosol-cooling element may have a width of between 5 millimetres and 10 millimetres, between 6 millimetres and 9 millimetres, or between 7 millimetres and 8 millimetres. The aerosol-cooling element may have a width that is substantially the same as the width of the aerosol-generating article.

[0193] The aerosol-generating substrate, susceptor and one or more other components of the aerosol-generating article may be assembled within one or more wrappers to form the aerosolgenerating article. For example, the aerosol-generating substrate, susceptor and other components of the aerosol-generating article may be assembled within one or more wrappers to form an elongate rod.

[0194] Suitable wrappers for use in aerosol-generating articles according to the first aspect of the invention are known in the art and include, but are not limited to: cigarette papers; filter plug wraps; tipping papers; metallised papers; metal foils; and metal foil-paper laminates.

[0195] The aerosol-generating article may comprise a ventilation zone located between the aerosol-generating substrate and the proximal end of the aerosol-generating article.

[0196] Where the aerosol-generating article comprises an aerosol-cooling element, the ventilation zone may be provided at a location along the aerosol-cooling element.

[0197] The ventilation zone typically comprises a plurality of perforations through the peripheral wall of the hollow tubular element. Preferably, the ventilation zone comprises at least one circumferential row of perforations. In some embodiments, the ventilation zone comprises two circumferential rows of perforations. For example, the perforations may be formed online during manufacturing of the aerosol-generating article. Preferably, each circumferential row of perforations comprises from 8 to 30 perforations.

[0198] An aerosol-generating article of the aerosol-generating systems of the present invention preferably has a ventilation level of at least 25 percent.

[0199] The term “ventilation level” is used throughout the present specification to denote a volume ratio between of the airflow admitted into the aerosol-generating article via the ventilation zone (ventilation airflow) and the sum of the aerosol airflow and the ventilation airflow. The greater the ventilation level, the higher the dilution of the aerosol flow delivered to the consumer. The aerosolgenerating article preferably has a ventilation level of at least 25 percent, more preferably at least 30 percent, even more preferably at least 40 percent, even more preferably at least 50 percent.

[0200] An aerosol-generating article of the present invention preferably has a ventilation level of up to 90 percent. Preferably, an aerosol-generating article in accordance with the present invention has a ventilation level of less than or equal to 80 percent, more preferably less than or equal to 70 percent, even more preferably less than or equal to 60 percent.

[0201] For example, an aerosol-generating article of the present invention preferably has a ventilation level from 25 percent to 90 percent, preferably from 30 percent to 80 percent, more preferably from 40 percent to 70 percent, even more preferably from 50 percent to 60 percent.

[0202] Aerosol-generating articles according to the invention may be assembled using known methods and machinery.

[0203] The present invention further provides an aerosol-generating system comprising an aerosol-generating article according to the invention, as described above, and an electrically operated aerosol-generating device comprising a heater element configured to heat the aerosolgenerating substrate of the aerosol-generating article.

[0204] The aerosol-generating device comprises means for heating the aerosol-generating substrate to a temperature sufficient to generate an aerosol from the aerosol-generating substrate. Preferably, the aerosol-generating device comprises a housing defining a cavity configured to receive the aerosol-generating article, and means for heating the aerosolgenerating substrate to a temperature sufficient to generate an aerosol from the aerosolgenerating substrate when the aerosol-generating article is received within the cavity.

[0205] The aerosol-generating device may be a handheld aerosol-generating device.

[0206] The aerosol-generating device may be an electrically-operated aerosol-generating device.

[0207] The aerosol-generating device may comprise a power supply and control electronics.

[0208] The aerosol-generating device may comprise a battery and control electronics.

[0209] The aerosol-generating device may be configured to heat the aerosol-generating substrate internally. That is, the aerosol-generating device may be configured to supply heat to the aerosolgenerating substrate from a location internal to the aerosol-generating article.

[0210] For example, in some embodiments the aerosol-generating device comprises a heater element configured to be inserted into the aerosol-generating substrate when the aerosolgenerating article is received within the cavity of the aerosol-generating device.

[0211] In other embodiments, the aerosol-generating article comprises a susceptor element provided at a location within the aerosol-generating substrate, and the aerosol-generating device comprises an inductor coil positioned on or within the housing, a power supply of the aerosol- generating device being connected to the inductor coil and configured to provide a high frequency oscillating current to the inductor coil.

[0212] The aerosol-generating device may be configured to heat the aerosol-generating substrate externally. That is, the aerosol-generating device may be configured to supply heat to the aerosolgenerating substrate from a location external to the aerosol-generating article. For example, in some embodiments the aerosol-generating device comprises a heater element located about a perimeter of the cavity and configured to heat the aerosol-generating substrate of the aerosolgenerating article from an exterior of the aerosol-generating element of the aerosol-generating article.

[0213] 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.

[0214] EX1. An aerosol-generating substrate for use in an aerosol-generating article or system, the aerosol-generating substrate comprising a homogenised plant material, the homogenised plant material comprising: non-tobacco plant particles selected from: black tea particles, apple fibre particles, rosehip seed particles, lemon balm stem particles and combinations thereof; aerosol former; exogenous binder; additional fibres; and active agent.

[0215] EX2. An aerosol-generating substrate according to example EX1 , wherein the homogenised plant material comprises at least 50 percent by weight of the non-tobacco plant particles, on a dry weight basis.

[0216] EX3. An aerosol-generating substrate according to example EX1 or EX2, wherein the total content of non-tobacco plant particles in the homogenised plant material is at least 55 percent by weight, for example at least 60 percent by weight, on a dry weight basis.

[0217] EX4. An aerosol-generating substrate according to any of the preceding examples, wherein the total content of non-tobacco plant particles in the homogenised plant material is less than or equal to 75 percent by weight, for example, less than or equal to 70 percent by weight, for example, less than or equal to 65 percent by weight, on a dry weight basis.

[0218] EX5. An aerosol-generating substrate according to any of the preceding examples, wherein the non-tobacco plant particles are selected from black tea particles, apple fibre particles or a combination thereof.

[0219] EX6. An aerosol-generating substrate according to any of the preceding examples, wherein the D90 value of the non-tobacco plant particles is at least 30 microns, for example at least 40 microns, for example at least 50 microns. EX7. An aerosol-generating substrate according to any of the preceding examples, wherein the D90 value of the non-tobacco plant particles is less than or equal to 150 microns, for example less than or equal to 120 microns, for example less than or equal to 80 microns.

[0220] EX8. An aerosol-generating substrate according to any of the preceding examples, wherein the diameter of 100 percent of the non-tobacco plant particles is less than or equal to 300 microns.

[0221] EX9. An aerosol-generating substrate according to any of the preceding examples, wherein the homogenised plant material comprises less than 5 percent by weight of tobacco particles, on a dry weight basis.

[0222] EX10. An aerosol-generating substrate according to any of the preceding examples, wherein the homogenised plant material is substantially free from tobacco.

[0223] EX11. An aerosol-generating substrate according to any of the preceding examples, wherein the homogenised plant material comprises less than 45 percent by weight of the non- tobacco plant particles, on a dry weight basis.

[0224] EX12. An aerosol-generating substrate according to any of the preceding examples, wherein the homogenised plant material comprises at least 10 percent by weight of aerosol former, on a dry weight basis.

[0225] EX13. An aerosol-generating substrate according to any of the preceding examples, wherein the homogenised plant material has an aerosol former content of at least 12 percent by weight, for example at least 15 percent by weight, on a dry weight basis.

[0226] EX14. An aerosol-generating substrate according to any of the preceding examples, wherein the homogenised plant material has an aerosol former content of less than or equal to 35 percent by weight, for example less than or equal to 30 percent by weight, for example less than or equal to 25 percent by weight, for example less than or equal to 20 percent by weight, on a dry weight basis.

[0227] EX15. An aerosol-generating substrate according to any of the preceding examples, wherein the aerosol former comprises glycerol.

[0228] EX16. An aerosol-generating substrate according to any of the preceding examples, wherein the weight ratio of non-tobacco plant particles to aerosol former in the homogenised plant material is between 1.5 and 5.

[0229] EX17. An aerosol-generating substrate according to any of the preceding examples, wherein the homogenised plant material comprises at least 2 percent by weight of the exogenous binder.

[0230] EX18. An aerosol-generating substrate according to any of the preceding examples, wherein the homogenised plant material has an exogenous binder content of at least 2.5 percent by weight, for example at least 3 percent by weight, on a dry weight basis. EX19. An aerosol-generating substrate according to any of the preceding examples, wherein the homogenised plant material has an exogenous binder content of less than or equal to 10 percent by weight, for example less than or equal to 7.5 percent by weight, for example less than or equal to 5 percent by weight, on a dry weight basis.

[0231] EX20. An aerosol-generating substrate according to any of the preceding examples, wherein the exogenous binder comprises guar gum, carboxymethyl cellulose, or a combination thereof.

[0232] EX21. An aerosol-generating substrate according to any of the preceding examples, wherein the homogenised plant material comprises at least 2 percent by weight of the additional fibres, on a dry weight basis.

[0233] EX22. An aerosol-generating substrate according to any of the preceding examples, wherein the additional fibre content of the homogenised plant material is at least 3 percent by weight, for example at least 4 percent by weight, on a dry weight basis.

[0234] EX23. An aerosol-generating substrate according to any of the preceding examples, wherein the additional fibre content of the homogenised plant material is less than or equal to 10 percent by weight, for example less than or equal to 8 percent by weight, for example less than or equal to 6 percent by weight, on a dry weight basis.

[0235] EX24. An aerosol-generating substrate according to any of the preceding examples, wherein the additional fibres comprise cellulose fibres.

[0236] EX25. An aerosol-generating substrate according to any of the preceding examples, wherein the additional fibres have lengths of greater than 400 micrometres.

[0237] EX26. An aerosol-generating substrate according to any of the preceding examples, wherein the weight ratio of the additional fibres to the exogenous binder in the homogenised plant material is between 1 and 2.5.

[0238] EX27. An aerosol-generating substrate according to any of the preceding examples, wherein the homogenised plant material comprises at least 0.5 percent by weight of the active agent, on a dry weight basis.

[0239] EX28. An aerosol-generating substrate according to any of the preceding examples, wherein the total active agent content of the homogenised plant material is at least 1 percent by weight, for example at least 1.25 percent by weight, for example at least 1.5 percent by weight, on a dry weight basis.

[0240] EX29. An aerosol-generating substrate according to any of the preceding examples, wherein the total active agent content of the homogenised plant material is less than or equal to 10 percent by weight, for example less than or equal to 8 percent by weight, for example less than or equal to 5 percent by weight, on a dry weight basis.

[0241] EX29. An aerosol-generating substrate according to any of the preceding examples, wherein the active agent comprises nicotine. EX30. An aerosol-generating substrate according to example EX29, wherein the homogenised plant material has a nicotine content of between 0.5 percent and 10 percent by weight, for example between 1 percent by weight and 8 percent by weight, for example between 1 .25 percent by weight and 5 percent by weight, for example between 1 .5 percent by weight and 2.5 percent by weight, on a dry weight basis.

[0242] EX31. An aerosol-generating substrate according to any of the preceding examples, wherein the homogenised plant material further comprises one or more flavourants.

[0243] EX32. An aerosol-generating substrate according to example EX31 , wherein the homogenised plant material has a flavourant content of between 0.5 percent by weight and 10 percent by weight, for example between 1 percent by weight and 8 percent by weight, for example between 2 percent by weight and 5 percent by weight, on a dry weight basis.

[0244] EX33. An aerosol-generating substrate according to any of the preceding examples, wherein the homogenised plant material further comprises an acidic pH modifier.

[0245] EX34. An aerosol-generating substrate according to example EX33, wherein the acidic pH modifier comprises one or more carboxylic acids.

[0246] EX35. An aerosol-generating substrate according to example EX34, wherein the acidic pH modifier comprises at least one of lactic acid and levulinic acid.

[0247] EX36. An aerosol-generating substrate according to any of examples EX33 to EX35, wherein the homogenised plant material comprises at least 1 percent by weight of the acidic pH modifier, on a dry weight basis.

[0248] EX37. An aerosol-generating substrate according to any of examples EX33 to EX36, wherein the homogenised plant material comprises less than or equal to 2 percent by weight of the acidic pH modifier.

[0249] EX38. An aerosol-generating substrate according to any of the preceding examples, wherein the homogenised plant material has a pH of less than or equal to 6.

[0250] EX39. An aerosol-generating substrate according to any of the preceding examples, wherein the homogenised plant material has a pH of at least 4.

[0251] EX40. An aerosol-generating substrate according to any of the preceding examples, wherein the further comprises an inert filler.

[0252] EX41. An aerosol-generating substrate according to example EX40, wherein the inert filler is selected from cellulose powder, microcrystalline cellulose (MCC), maltodextrin, or combinations thereof.

[0253] EX42. An aerosol-generating substrate according to any of the preceding examples, wherein the aerosol-generating substrate is in the form of one or more sheets of homogenised plant material.

[0254] EX43. An aerosol-generating substrate according to any of the preceding examples, wherein the aerosol-generating substrate comprises one or more sheets of the homogenised plant material and wherein each sheet has an average thickness of between 150 microns and 500 microns, for example between 200 microns and 400 microns, for example between 250 microns and 350 microns.

[0255] EX44. An aerosol-generating substrate according to any of the preceding examples, wherein the aerosol-generating substrate comprises one or more sheets of the homogenised plant material and wherein each sheet has a grammage of between 100 grams per square metre and 300 grams per square metre, for example between 150 grams per square metre and 250 grams per square metre, for example between 150 grams per square metre and 200 grams per square metre.

[0256] EX45. An aerosol-generating substrate according to any of the preceding examples, wherein the aerosol-generating substrate comprises one or more sheets of the homogenised plant material and wherein each sheet has a density of from 0.3 grams per cubic centimetre to 1 .3 grams per cubic centimetre, for example from 0.4 grams per cubic centimetre to 1 .0 grams per cubic centimetre, for example from 0.5 grams per cubic centimetre to 0.9 grams per cubic centimetre.

[0257] EX46. An aerosol-generating substrate according to any of the preceding examples, wherein the aerosol-generating substrate comprises one or more sheets of the homogenised plant material and wherein each sheet has a tensile strength at peak in a cross direction of between 150 N / m and 500 N / m.

[0258] EX47. An aerosol-generating substrate according to any of the preceding examples, wherein the aerosol-generating substrate comprises one or more sheets of the homogenised plant material and wherein each sheet has a tensile strength at peak in a machine direction of between 400 N / m and 650 N / m.

[0259] EX48. An aerosol-generating substrate according to any of the preceding examples, wherein the homogenised plant material is in the form of cast leaf.

[0260] EX49. An aerosol-generating substrate according to any of examples EX1 to EX41 , wherein the aerosol-generating substrate comprises shredded homogenised plant material.

[0261] EX50. An aerosol-generating article comprising a rod of the aerosol-generating substrate according to any of the preceding examples, circumscribed by a wrapper.

[0262] EX51. An aerosol-generating article according to example EX50, wherein the aerosolgenerating substrate has a density of less than or equal to 1000 milligrams per cubic centimetre.

[0263] EX52. An aerosol-generating article according to example EX50 or EX51 , wherein the aerosol-generating substrate has a density of at least 200 milligrams per cubic centimetre.

[0264] EX53. An aerosol-generating article according to any of examples EX50 to EX52, wherein the rod of aerosol-generating substrate further comprises one or more elongate susceptor elements. EX54. An aerosol-generating article according to any of examples EX50 to EX53, wherein the rod of aerosol-generating substrate has a length of at least 10 millimetres.

[0265] EX55. An aerosol-generating article according to any of examples EX50 to EX54, further comprising an upstream section provided upstream of the rod of aerosol-generating substrate, the upstream section comprising at least one upstream element.

[0266] EX56. An aerosol-generating article according to example EX55, wherein the upstream element has a length of between 2 millimetres and 8 millimetres.

[0267] EX57. An aerosol-generating article according to any of examples EX50 to EX56, further comprising a downstream section provided downstream of the rod of aerosol-generating substrate, the downstream section comprising at least one hollow tubular element abutting a downstream end of the rod of aerosol-generating substrate.

[0268] EX58. An aerosol-generating article according to example EX57, further comprising a ventilation zone provided at a location along the hollow tubular element of the downstream section.

[0269] EX59. An aerosol-generating article according to example EX57, wherein the hollow tubular element of the downstream section has a length of between 17 millimetres and 25 millimetres.

[0270] EX60. An aerosol-generating article according to example EX57, wherein the downstream section further comprises a mouthpiece element.

[0271] EX61. An aerosol-generating article according to example EX57, wherein the mouthpiece element comprises at least one mouthpiece filter segment formed of a fibrous filtration material.

[0272] EX62. An aerosol-generating article according to example EX60 or EX61, wherein the length of the mouthpiece element is between 3 millimetres and 15 millimetres.

[0273] EX63. An aerosol-generating article according to any of examples EX60 to EX62, wherein the mouthpiece element further comprises one or more breakable capsules containing a liquid flavourant.

[0274] EX64. An aerosol-generating system comprising an aerosol-generating article according to any of the examples EX50 to EX63 and an electrically operated aerosol-generating device comprising a heater element configured to heat the aerosol-generating substrate of the aerosolgenerating article.

[0275] EX65. A method of making an aerosol-generating substrate according to any of the examples EX1 to EX49, the method comprising the steps of: forming a slurry comprising non-tobacco plant particles, exogenous binder, aerosol former, additional fibres, active agent and water; casting the slurry in the form of a sheet; and drying the sheet at between 80 and 160 degrees Celsius. Examples will now be further described with reference to the drawings of the accompanying Figures in which:

[0276] Figure 1 is a schematic cross-sectional view of an embodiment of an aerosol generating article according to a first embodiment of the invention; and

[0277] Figure 2 is a schematic cross-sectional view of an embodiment of an aerosol-generating article according to a second embodiment of the invention.

[0278] The aerosol-generating article 1 shown in Figure 1 comprises a rod of aerosol-generating substrate 12, a downstream section 14 located downstream of the rod of aerosol-generating substrate 12 and an upstream section 16 located upstream of the rod of aerosol-generating substrate 12. As shown in Figure 1 , the aerosol-generating article 1 has an upstream end 48 and a downstream end 20. The aerosol-generating article 1 may have an overall length of 45 millimetres and an external diameter of 7.2 millimetres.

[0279] The aerosol-generating article 1 further comprises an elongate susceptor element 44 within the rod 12 of aerosol-generating substrate. In more detail, the susceptor element 44 is arranged substantially longitudinally within the aerosol-generating substrate, such as to be approximately parallel to the longitudinal direction of the rod 12. As shown in the drawing of Figure 1 , the susceptor element 44 is positioned in a radially central position within the rod and extends effectively along the longitudinal axis of the rod 12.

[0280] The susceptor element 44 extends all the way from an upstream end to a downstream end of the rod 12. In effect, the susceptor element 44 has substantially the same length as the rod 12 of aerosol-generating substrate.

[0281] In the embodiment of Figure 1 , the susceptor element 44 is provided in the form of a strip and has a length of about 12 millimetres, a thickness of about 60 micrometres, and a width of about 4 millimetres.

[0282] The upstream section 16 comprises an upstream element 46 located immediately upstream of the rod 12 of aerosol-generating substrate, the upstream element 46 being in longitudinal alignment with the rod 12. In the embodiment of Figure 1 , the downstream end of the upstream element 46 abuts the upstream end of the rod 12 of aerosol-generating substrate. This advantageously prevents the susceptor element 44 from being dislodged. Further, this ensures that the consumer cannot accidentally contact the heated susceptor element 44 after use.

[0283] The upstream element 46 is in the form of a cylindrical plug of cellulose acetate circumscribed by a stiff wrapper. The upstream element 46 may have a length of 5 millimetres and an external diameter of 6.9 millimetres.

[0284] The downstream section 14 of the aerosol-generating article 1 comprises a support element 22 located immediately downstream of the rod of aerosol-generating substrate 12, an aerosolcooling element 24 located immediately downstream of the support element 22, and a mouthpiece element 42 located immediately downstream of the aerosol-cooling element 24. The support element 22 and the aerosol-cooling element 24 together define an intermediate hollow section 50 of the aerosol-generating article 1.

[0285] The support element 22 comprises a first hollow tubular element 26. The first hollow tubular element 26 is in the form of a hollow cylindrical tube made of cellulose acetate. The first hollow tubular element 26 defines an internal cavity 28 that extends from an upstream end 30 of the first hollow tubular element to a downstream end 32 of the first hollow tubular element 20. The first hollow tubular element 26 may have a length of 8 millimetres and an external diameter of 6.9 millimetres. The first hollow tubular element 26 may have an internal diameter of 1.9 millimetres.

[0286] The aerosol-cooling element 24 comprises a second hollow tubular element 34. The second hollow tubular element 34 is in the form of a hollow cylindrical tube made of cellulose acetate. The second hollow tubular element 34 defines an internal cavity 36 that extends from an upstream end 38 of the second hollow tubular element to a downstream end 40 of the second hollow tubular element 34. The second hollow tubular element 34 may have a length of 13 millimetres and an external diameter of 6.9 millimetres. The second hollow tubular element 34 may have an internal diameter of 3.25 millimetres.

[0287] As shown by the dashed vertical line in Figure 1 , the aerosol-generating article 1 comprises a ventilation zone 60 provided at a location along the second hollow tubular element 34. The ventilation zone may be provided 2 millimetres from the upstream end of the second hollow tubular element 34. A ventilation level of the aerosol-generating article 1 may be 35 percent.

[0288] The mouthpiece element 42 is in the form of a cylindrical plug of low-density cellulose acetate. The mouthpiece element 42 may have a length of 7 millimetres and an external diameter of 6.9 millimetres.

[0289] The mouthpiece element 42 contains a flavourant capsule 44 embedded within the plug of cellulose acetate. The flavourant capsule 44 is spherical in shape and has a diameter of 2 millimetres. The flavourant capsule 44 has a core shell structure, with an inner core containing a liquid flavourant comprising menthol. The flavourant capsule 44 is breakable by applying a compressive force to the mouthpiece element 42 and may be broken before, during or after smoking.

[0290] The rod of aerosol-generating substrate 12 may have a length of 12 millimetres and an external diameter of 6.9 millimetres.

[0291] The rod of aerosol-generating substrate 12 comprises a gathered sheet of homogenised plant material comprising non-tobacco plant particles. Suitable compositions are shown below in Table 1.

[0292] The homogenised plant material is produced by forming a slurry of the non-tobacco plant particles, binder, nicotine, glycerol and cellulose fibres in water. The slurry is cast onto a supportive surface to form a sheet and the sheet is dried. The non-tobacco plant particles have a D90 value of 75 microns. The resultant sheet had a density of approximately 800 milligrams per cubic centimetre and a grammage of approximately 195 grams per square metre.

[0293]

[0294] Table 1

[0295] In use, a user draws on the mouthpiece element 42 of the aerosol-generating article 1. When a user draws on the mouthpiece 42, air is drawn into the aerosol-generating article 1 through the upstream end 48. The drawn air passes through the upstream element 46 to the rod of aerosol-generating substrate 12. Heating of the rod of aerosol-generating substrate releases volatile and semi-volatile compounds, which form an aerosol that is entrained in the drawn air as it flows through the rod of aerosol-generating substrate 12. The drawn air and entrained aerosol pass through the intermediate hollow section 50 of the aerosol-generating article 1, where they cool and condense. The cooled aerosol then passes through the mouthpiece element 42 of the aerosol-generating article 1 and into the mouth of the user.

[0296] The aerosol-generating article 2 shown in Figure 2 comprises a rod of aerosol-generating substrate 212, a downstream section 214 located downstream of the rod of aerosol-generating substrate 212 and an upstream section 216 located upstream of the rod of aerosol-generating substrate 212. As shown in Figure 2, the aerosol-generating article 2 has an upstream end 248 and a downstream end 220. The aerosol-generating article 2 may have an overall length of 45 millimetres and an external diameter of 7.2 millimetres.

[0297] The upstream section 216 of the aerosol-generating article 2 comprises an upstream element 346 located immediately upstream of the rod of aerosol-generating substrate 212. The upstream element 246 is in the form of a cylindrical plug of cellulose acetate circumscribed by a stiff wrapper. The upstream element 246 may have a length of 5 millimetres, an external diameter of 6.9 millimetres and an internal diameter of 5.1 millimetres.

[0298] The downstream section 214 of the aerosol-generating article 2 comprises an aerosolcooling element 224 located immediately downstream of the rod of aerosol-generating substrate 212, and a mouthpiece element 42 located immediately downstream of the aerosol-cooling element 224. The aerosol-cooling element 224 defines an intermediate hollow section 250 of the aerosol-generating article 2.

[0299] The aerosol-cooling element 224 comprises a hollow tubular element 234. The hollow tubular element 234 is in the form of a hollow cylindrical tube made of cellulose acetate. The hollow tubular element 234 defines an internal cavity 236 that extends from an upstream end 238 of the hollow tubular element to a downstream end 240 of the hollow tubular element 234. The hollow tubular element 234 may have a length of 18 millimetres and an external diameter of 6.9 millimetres. The hollow tubular element 234 may have an internal diameter of 3.25 millimetres.

[0300] The mouthpiece element 242 is in the form of a cylindrical plug of low-density cellulose acetate. The mouthpiece element 242 may have a length of 7 millimetres and an external diameter of 6.9 millimetres.

[0301] The mouthpiece element 242 contains a flavourant capsule 244 embedded within the plug of cellulose acetate. The flavourant capsule 244 is spherical in shape and has a diameter of 2 millimetres. The flavourant capsule 244 has a core shell structure, with an inner core containing a liquid flavourant comprising menthol. The flavourant capsule 244 is breakable by applying a compressive force to the mouthpiece element 242 and may be broken before, during or after smoking.

[0302] The rod of aerosol-generating substrate 212 may have a length of 17 millimetres and an external diameter of 6.9 millimetres.

[0303] The rod of aerosol-generating substrate 212 comprises a shredded homogenised plant material. Suitable compositions for the homogenised plant material are shown above in Table 1.

[0304] In use, a user draws on the mouthpiece element 242 of the aerosol-generating article 2. When a user draws on the mouthpiece 242, air is drawn into the aerosol-generating article 2 through the upstream end 248. The drawn air passes to the rod of aerosol-generating substrate 212. Heating of the rod of aerosol-generating substrate releases volatile and semi-volatile compounds, which form an aerosol that is entrained in the drawn air as it flows through the rod of aerosol-generating substrate 212. The drawn air and entrained aerosol pass through the intermediate hollow section 250 of the aerosol-generating article 2, where they cool and condense. The cooled aerosol then passes through the mouthpiece element 242 of the aerosolgenerating article 2 and into the mouth of the user. As shown by the dashed vertical line in Figure 2, the aerosol-generating article 2 comprises a ventilation zone 260 provided at a location along the second hollow tubular element 234. A ventilation level of the aerosol-generating article 1 may be 35 percent.

[0305] For both aerosol-generating articles 1 and 2, the aerosols generated upon heating of the homogenised plant material produced according to Samples A and B above were found to have a mild, relatively neutral taste from the non-tobacco plant materials, with a consistent delivery of nicotine.

[0306] The specific embodiments and examples described above illustrate, but do not limit, the invention. It is to be understood that other embodiments of the invention may be made and the specific embodiments and examples described herein are not exhaustive.

[0307] 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". In this context, therefore, a number A is understood as A ± 10% 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

CLAIMS1. An aerosol-generating substrate for use in an aerosol-generating article or system, the aerosol-generating substrate comprising a homogenised plant material, the homogenised plant material comprising: at least 50 percent by weight of non-tobacco plant particles on a dry weight basis, the nontobacco plant particles selected from: black tea particles, apple fibre particles, rosehip seed particles, lemon balm stem particles and combinations thereof, wherein the D90 value of the nontobacco plant particles is less than or equal to 150 microns; at least 10 percent by weight of aerosol former on a dry weight basis; at least 2 percent by weight of exogenous binder on a dry weight basis; at least 2 percent by weight of additional fibres on a dry weight basis; and at least 0.5 percent by weight of active agent on a dry weight basis.

2. An aerosol-generating substrate according to claim 1 , wherein the homogenised plant material comprises less than 5 percent by weight of tobacco particles, on a dry weight basis.

3. An aerosol-generating substrate according to claim 1 or 2, wherein the homogenised plant material is substantially free from tobacco.

4. An aerosol-generating substrate according to any of claims 1 to 3, wherein the nontobacco plant particles comprise black tea particles, apple fibre particles or a combination thereof.

5. An aerosol-generating substrate according to any preceding claim, wherein the weight ratio of non-tobacco plant particles to aerosol former in the homogenised plant material is at least 1.5.

6. An aerosol-generating substrate according to any preceding claim, wherein the active agent comprises nicotine.

7. An aerosol-generating substrate according to any preceding claim, wherein the exogenous binder comprises guar gum, carboxymethyl cellulose or a combination thereof.

8. An aerosol-generating substrate according to any preceding claim, wherein the homogenised plant material further comprises an acidic pH modifier.

9. An aerosol-generating substrate according to any preceding claim, wherein the homogenised plant material is in the form of cast leaf.

10. An aerosol-generating substrate according to any preceding claim, wherein the additional fibres comprise cellulose fibres.

11. An aerosol-generating substrate according to any preceding claim, wherein the weight ratio of the additional fibres to the exogenous binder in the homogenised plant material is at leastI .

12. An aerosol-generating article comprising a rod of aerosol-generating substrate according to any preceding claim.

13. An aerosol-generating article according to claim 12, wherein the rod of aerosol-generating substrate further comprises a susceptor element within the aerosol-generating substrate.

14. A method for producing the aerosol-generating substrate according to any of claims 1 toI I , the method comprising the steps of: forming a slurry comprising non-tobacco plant particles, exogenous binder, additional fibres, active agent, aerosol former and water; casting the slurry in the form of a sheet; and drying the sheet at between 80 and 160 degrees Celsius wherein the non-tobacco plant particles are selected from black tea particles, apple fibre particles, rosehip seed particles, lemon balm stem particles and combinations thereof.

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