Aerosol generating article containing a hollow tubular element with a capsule

Abstract

An aerosol generating article (10, 100, or 200) for generating an inhalable aerosol when heated includes a hollow tubular element (12, 112, or 212) and a capsule (14, 114, or 214) mounted inside the hollow tubular element (12, 112, or 212) at the upstream end of the hollow tubular element (12, 112, or 212). The capsule (14, 114, or 214) includes a capsule outer wall (20) defining an internal cavity (22) having a volume of at least 250 cubic millimeters, and a solid aerosol generating substrate (24) inside the internal cavity (22) of the capsule (14, 114, or 214), the solid aerosol generating substrate (24) containing nicotine and an aerosol forming agent. The aerosol-forming material content of the aerosol-generating substrate (24) is at least 15 weight percent on a dry weight basis, and the density of the solid aerosol-generating substrate (24) within the capsule (14) is at least 0.1 milligrams per cubic millimeter of the internal cavity (22). The hollow tubular elements (12, 112, or 212) define an empty cavity (252) downstream of the capsule (14, 114, or 214).

Description

Technical Field

[0001] The present invention relates to an aerosol-generating article comprising an aerosol-generating substrate and adapted to generate an inhalable aerosol upon heating.

Background Art

[0002] Aerosol-generating articles in which an aerosol-generating substrate such as a tobacco-containing substrate is heated rather than burned are known in the art. Typically, in such heated smoking articles, an aerosol is generated by transferring heat from a heat source to a physically separated aerosol-generating substrate or material, which may be in contact with the heat source, within the heat source, around the heat source, or downstream of the heat source. During use of the aerosol-generating article, volatile compounds are released from the aerosol-generating substrate by heat transfer from the heat source and entrained in the air drawn through the aerosol-generating article. The released compounds condense as they are cooled to form an aerosol.

[0003] In a number of prior art documents, aerosol-generating devices for consuming aerosol-generating articles are disclosed. Such devices include, for example, an electrically heated aerosol-generating device in which an aerosol is generated by heat transfer from one or more electric heater elements of the aerosol-generating device to the aerosol-generating substrate of the heated aerosol-generating article. For example, an electrically heated aerosol-generating device has been proposed that includes an internal heater blade adapted to be inserted into the aerosol-generating substrate.

[0004] The use of aerosol-generating articles in combination with an external heating system is also known. For example, WO2020 / 115151 describes the provision of one or more heating elements arranged around the periphery of an aerosol-generating article when the aerosol-generating article is received within a cavity of an aerosol-generating device. Alternatively, an inductively heatable aerosol-generating article comprising an aerosol-generating substrate and a susceptor disposed within the aerosol-generating substrate has been proposed by WO2015 / 176898.

[0005] Certain types of aerosol-generating substrates containing nicotine and relatively high aerosol-forming content, such as nicotine-containing gels and films, are known. Such substrates are typically very stable during storage and, advantageously, provide very consistent delivery of nicotine to consumers upon heating. They also, advantageously, can generate aerosols at lower temperatures than other solid substrates. However, the use of this type of aerosol-generating substrate can also present problems. Relatively high aerosol-forming content increases the risk of aerosol-forming material leaking from the substrate during storage and use. Furthermore, certain substrates, such as gel compositions, generally melt upon heating of the aerosol-generating substrate within the aerosol generator during use. Consequently, the viscosity of the gel composition increases significantly, making it more difficult to control the movement of the gel composition, particularly to retain it within the aerosol-generating article. Leakage of aerosol-forming material or molten gel composition from the aerosol-generating article is undesirable because it can leak into the heating chamber of the aerosol generator and contaminate the device. Leakage of aerosol-forming materials or gel compositions can also be potentially unpleasant for consumers.

[0006] Therefore, it is desirable to provide a novel aerosol generating article having an arrangement that provides improved retention of the aerosol generating substrate within the aerosol generating article during storage and use. It is even more desirable to provide such aerosol generating articles that enable efficient heating of the aerosol generating substrate so that aerosols can be generated from the aerosol generating substrate in an efficient and consistent manner. [Overview of the project]

[0007] This disclosure relates to an aerosol generating article for generating an inhalable aerosol upon heating. The aerosol generating article may include a hollow tubular element. The aerosol generating article may further include a capsule mounted within the hollow tubular element. The capsule may be mounted on the upstream end of the hollow tubular element. The capsule may include a capsule outer wall defining an internal cavity. The internal cavity may have a volume of at least 250 cubic millimeters. The capsule may further include a solid aerosol generating substrate within the internal cavity of the capsule, the solid aerosol generating substrate containing nicotine and an aerosol forming agent. The aerosol forming agent content of the aerosol generating substrate may be at least 15 weight percent on a dry weight basis. The density of the solid aerosol generating substrate within the capsule may be at least 0.1 milligrams per cubic millimeter of the internal cavity.

[0008] According to the present invention, an aerosol generating article is provided for generating an inhalable aerosol upon heating, the aerosol generating article comprising a hollow tubular element and a capsule attached to the hollow tubular element at the upstream end of the hollow tubular element. The capsule comprises a capsule outer wall defining an internal cavity having a volume of at least 250 cubic millimeters and a solid aerosol generating substrate within the internal cavity of the capsule. The solid aerosol generating substrate comprises nicotine and an aerosol forming agent, the aerosol forming agent content of the aerosol generating substrate is at least 15 weight percent on a dry weight basis, and the density of the solid aerosol generating substrate within the capsule is at least 0.1 milligrams per cubic millimeter of the internal cavity.

[0009] As used herein, the term "aerosol-generating article" refers to an article that generates an inhalable aerosol by heating an aerosol-generating substrate and delivers it to a consumer. As used herein, the term "aerosol-generating substrate" means a substrate that has the ability to generate an aerosol by releasing volatile compounds upon heating.

[0010] As used herein, the term "aerosol generator" refers to a device comprising a heater element that interacts with an aerosol-generating substrate of an aerosol-generating article to generate an aerosol.

[0011] As used herein, the term "density" refers to the bulk density of the solid aerosol-generating substrate within the internal cavity. Density is calculated by dividing the total mass of the solid aerosol-generating substrate by the total volume of the internal cavity. Therefore, density corresponds to the weight of the solid aerosol-generating substrate per unit volume of the internal cavity. This is different from the density of the solid aerosol-generating substrate itself.

[0012] As used herein, the term “longitudinal direction” refers to the direction corresponding to the main longitudinal axis of the aerosol generating article, extending between the upstream and downstream ends of the aerosol generating article. As used herein, the terms “upstream” and “downstream” describe the relative position of an element (or part of an element) of the aerosol generating article with respect to the direction in which aerosols are transported through the aerosol generating article during use.

[0013] During use, air is drawn through the aerosol-generating article in the longitudinal direction. The term "transverse direction" refers to the direction perpendicular to the longitudinal axis. Any reference to the "cross section" of the aerosol-generating article or its components refers to the transverse section unless otherwise specified.

[0014] The term "length" refers to the dimensions of the components of an aerosol-generating article in the longitudinal direction. For example, it may be used to refer to the dimensions of a hollow tubular element or capsule in the longitudinal direction.

[0015] As used herein, the term “solid” refers to an aerosol-generating substrate that, rather than being a liquid or gas, retains its shape and becomes low enough to form at room temperature. In the context of this invention, the term “solid” encompasses gel materials and compositions.

[0016] The present invention relates to an aerosol generating article having a unique configuration comprising a hollow tubular element and a capsule mounted within the hollow tubular element, wherein the capsule contains a solid aerosol generating substrate. Additional components may or may not be provided downstream of the capsule within the hollow tubular element, as will be discussed in more detail below. The use of a capsule for holding the solid aerosol generating substrate within the aerosol generating article provides a highly effective method for holding the aerosol generating substrate in a fixed position within the aerosol generating article during storage and use. As will be described in more detail below, the capsule may be provided with an airflow path to enable highly effective heating of the aerosol generating substrate and generation of aerosol from the aerosol generating substrate within the capsule. The resulting aerosol can be efficiently delivered to the consumer along the hollow tubular element.

[0017] Placing capsules within hollow tubular elements is relatively simple, and therefore the amount of material required to manufacture aerosol-generating articles can be advantageously reduced compared to existing aerosol-generating articles with more complex structures. In particular, when an aerosol-generating substrate that can generate aerosols at relatively low temperatures, such as a gel composition, is used, it is possible to produce the aerosol-generating articles according to the present invention with minimal filtration material downstream of the capsule.

[0018] The configuration of the present invention is particularly beneficial for aerosol-generating substrates having a relatively high aerosol-forming content, such as aerosol-generating films and gel compositions of the types described below. Encapsulating the aerosol-generating substrate in a capsule prevents leakage of the aerosol-forming material from the aerosol-generating substrate during storage or use. Furthermore, if the aerosol-generating substrate melts upon heating, as in the case of many gel compositions, the molten substrate can be effectively retained within the capsule. Therefore, leakage of the aerosol-forming material or aerosol-generating substrate from the aerosol-generating article during use can be substantially prevented, and as a result, the risk of contamination of the aerosol generator is advantageously minimized.

[0019] As described above, the aerosol generating article of the present invention includes a solid aerosol generating substrate contained within a capsule. The solid aerosol generating substrate includes nicotine and an aerosol forming agent, but can take on various different forms.

[0020] According to the present invention, the aerosol generating substrate contains at least 15 weight percent of aerosol forming material on a dry weight basis. Preferably, the aerosol generating substrate contains at least 20 weight percent of aerosol forming material on a dry weight basis. More preferably, the aerosol generating substrate contains at least 25 weight percent of aerosol forming material on a dry weight basis. More preferably, the aerosol generating substrate contains at least 30 weight percent of aerosol forming material on a dry weight basis. More preferably, the aerosol generating substrate contains at least 35 weight percent of aerosol forming material on a dry weight basis. More preferably, the aerosol generating substrate contains at least 40 weight percent of aerosol forming material on a dry weight basis. It is more preferable that the aerosol generating substrate contains at least 45 weight percent of aerosol forming material on a dry weight basis. More preferably, the aerosol generating substrate contains at least 50 weight percent of aerosol forming material on a dry weight basis.

[0021] The aerosol generating substrate preferably contains 80% by weight or less on a dry weight basis. The second aerosol generating substrate more preferably contains 75% by weight or less on a dry weight basis. The second aerosol generating substrate more preferably contains 70% by weight or less on a dry weight basis.

[0022] For example, the aerosol generating substrate may result in an aerosol-forming content of 15% to 80% by weight, or 20% to 80% by weight, or 25% to 80% by weight, or 30% to 75% by weight, or 35% to 75% by weight, or 40% to 70% by weight, or 45% to 70% by weight, or 50% to 70% by weight, on a dry weight basis.

[0023] In certain preferred embodiments, the water content of the aerosol-forming material of the aerosol-generating substrate may be 40% to 80% by weight, or 45% to 75% by weight, or 50% to 70% by weight, on a dry weight basis. In such embodiments, the aerosol-forming material content of the aerosol-generating substrate is therefore relatively high.

[0024] Suitable aerosol-forming materials for inclusion in aerosol-generating substrates 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 dodecanediic acid and dimethyl tetradecanediic acid).

[0025] The aerosol generating substrate preferably contains glycerol as an aerosol forming body. For example, the aerosol generating substrate may have a glycerol content of 15% to 80% by weight, or 20% to 80% by weight, or 25% to 80% by weight, or 30% to 75% by weight, or 35% to 75% by weight, or 40% to 70% by weight, or 45% to 70% by weight, or 50% to 70% by weight, on a dry weight basis.

[0026] The aerosol-generating substrate further comprises nicotine. As used herein in relation to the present invention, the term "nicotine" is used to describe nicotine, a nicotine base, or a nicotine salt. In embodiments in which the aerosol-generating substrate comprises a nicotine base or a nicotine salt, the amounts of nicotine listed herein are, respectively, amounts of free base nicotine or amounts of protonated nicotine.

[0027] The aerosol generating substrate may contain natural nicotine or synthetic nicotine.

[0028] Nicotine may contain one or more nicotine salts. The one or more nicotine salts may be selected from the list consisting of nicotine lactate, nicotine citrate, nicotine pyruvate, nicotine bitartrate, nicotine benzoate, nicotine pectinate, nicotine alginate, and nicotine salicylate.

[0029] Nicotine may contain an extract of tobacco.

[0030] Preferably, the aerosol generating substrate contains at least 0.5 weight percent nicotine on a dry weight basis. More preferably, the aerosol generating substrate contains at least 1 weight percent nicotine on a dry weight basis. Even more preferably, the aerosol generating substrate contains at least 2 weight percent nicotine on a dry weight basis. Additionally or alternatively, preferably, the aerosol generating substrate contains less than 10 weight percent nicotine on a dry weight basis. More preferably, the aerosol generating substrate contains less than 8 weight percent nicotine on a dry weight basis. Even more preferably, the aerosol generating substrate contains less than 6 weight percent nicotine on a dry weight basis.

[0031] For example, the aerosol generating substrate may contain 0.5 weight percent to 10 weight percent nicotine, or 1 weight percent to 8 weight percent nicotine, or 2 weight percent to 6 weight percent nicotine on a dry weight basis.

[0032] The aerosol forming substrate may contain one or more carboxylic acids. Advantageously, the inclusion of one or more carboxylic acids in the aerosol forming substrate may produce nicotine salts.

[0033] The one or more carboxylic acids include one or more of lactic acid and levulinic acid. Advantageously, the inventors have discovered that lactic acid and levulinic acid are particularly good carboxylic acids for producing nicotine salts.

[0034] Preferably, the aerosol-forming substrate contains at least 0.5 weight percent of carboxylic acid on a dry weight basis. More preferably, the aerosol-forming substrate contains at least 1 weight percent of carboxylic acid on a dry weight basis. More preferably, the aerosol-forming substrate contains at least 2 weight percent of nicotine on a dry weight basis.

[0035] In addition, or alternatively, the aerosol generating substrate preferably contains less than 15 weight percent of carboxylic acid on a dry weight basis. More preferably, the aerosol generating substrate preferably contains less than 10 weight percent of carboxylic acid on a dry weight basis. More preferably, the aerosol generating substrate preferably contains less than 5 weight percent of carboxylic acid on a dry weight basis. For example, the aerosol generating substrate may contain 0.5 to 15 weight percent of carboxylic acid, or 1 to 10 weight percent of carboxylic acid, or 2 to 5 weight percent of carboxylic acid.

[0036] In certain preferred embodiments, the aerosol-generating substrate is in the form of an aerosol-generating film comprising a cellulosic film-forming agent, nicotine, and an aerosol-forming agent. The aerosol-generating film may further contain a cellulosic reinforcing agent. The aerosol-generating film may further contain less than 30 percent by weight of water.

[0037] As used herein, the term “film” is used to describe a solid layered element having a thickness less than its width or length. A film may be self-supporting. In other words, a film may have cohesive and mechanical properties that allow it to be separated from a support surface, even if it is obtained by casting a film-forming formulation onto a support surface. Alternatively, a film may be placed on a support or sandwiched between other materials. This can enhance the mechanical stability of the film.

[0038] The aerosol-forming material content of the aerosol-generating film is within the range defined above for the aerosol-generating substrate.

[0039] In the context of the present invention, the term "cellulose-based film-forming agent" is used to describe a cellulose polymer that has the ability to form a continuous film, either by itself or in the presence of an auxiliary thickener.

[0040] Preferably, the cellulosic film-forming agent is selected from the group consisting of hydroxypropyl methylcellulose (HPMC), methylcellulose (MC), ethylcellulose (EC), hydroxyethyl methylcellulose (HEMC), hydroxyethylcellulose (HEC), hydroxypropylcellulose (HPC), and combinations thereof.

[0041] More preferably, the cellulosic film-forming agent is selected from the group consisting of hydroxypropyl methylcellulose (HPMC), methylcellulose (MC), ethylcellulose (EC), and combinations thereof.

[0042] In a particularly preferred embodiment, the cellulosic film-forming agent is HPMC.

[0043] The aerosol-generating film may contain a cellulose-based film-forming agent of 10% to 40% by weight, or 15% to 35% by weight, or 20% to 30% by weight, on a dry weight basis.

[0044] The aerosol-generating film preferably further contains a cellulose-based reinforcing agent. The cellulose-based reinforcing agent is preferably selected from the group consisting of cellulose fibers, microcrystalline cellulose (MCC), cellulose powder, and combinations thereof.

[0045] The aerosol-generating film may contain a cellulosic reinforcing agent of 0.5% to 40% by dry weight, or 5% to 30% by dry weight, or 10% to 25% by dry weight.

[0046] The aerosol-generating film may further contain carboxymethylcellulose, preferably sodium carboxymethylcellulose.

[0047] The aerosol-generating film may have a carboxymethylcellulose content of 1% to 15% by weight, or 2% to 12% by weight, or 4% to 10% by weight, on a dry weight basis.

[0048] The nicotine content of the aerosol-generating film is within the range defined above for the aerosol-generating substrate.

[0049] The aerosol generating film may be a substantially tobacco-free aerosol generating film.

[0050] In preferred embodiments, the aerosol generating film contains an acid. More preferably, the aerosol generating film contains one or more organic acids. Even more preferably, the aerosol generating film contains one or more carboxylic acids. In particularly preferred embodiments, the acid is lactic acid, benzoic acid, fumaric acid, or levulinic acid.

[0051] The aerosol-generating film preferably contains 0.25% to 3.5% by weight of acid, or 0.5% to 3% by weight of acid, or about 1% to 2.5% by weight of acid, on a dry weight basis.

[0052] In preferred embodiments, the aerosol-generating film has a thickness of about 0.1 mm to about 1 mm, more preferably about 0.1 mm to about 0.75 mm, and even more preferably about 0.1 mm to about 0.5 mm. In particularly preferred embodiments, a layer of film-forming composition is formed having a thickness of about 50 micrometers to 400 micrometers, more preferably about 100 micrometers to 200 micrometers.

[0053] The aerosol-generating film may optionally be provided on a suitable carrier element.

[0054] In alternative preferred embodiments of the present invention, the aerosol generating substrate comprises a gel composition containing nicotine, at least one gelling agent, and an aerosol forming body. The gel composition is preferably substantially free of tobacco.

[0055] The preferred weight range of nicotine in the gel composition is the same as that defined above in relation to the aerosol generating film.

[0056] The gel composition preferably contains at least 50 weight percent of aerosol-forming material, more preferably at least 60 weight percent, and more preferably at least 70 weight percent, on a dry weight basis. The gel composition may contain up to 80 weight percent of aerosol-forming material. The aerosol-forming material in the gel composition is preferably glycerol.

[0057] The gel composition preferably contains at least one gelling agent. Preferably, the gel composition contains a total amount of gelling agent ranging from about 0.4% to about 10% by weight, or about 0.5% to about 8% by weight, or about 1% to about 6% by weight, or about 2% to about 4% by weight, or about 2% to about 3% by weight.

[0058] The term "gelling agent" refers to a compound that, when added homogeneously to a mixture of 50% water and 50% glycerol in an amount of approximately 0.3% by weight, forms a solid medium or supporting matrix, leading to the formation of a gel. Examples of gelling agents, though not limited to them, include hydrogen-linked gelling agents and ionic-linked gelling agents.

[0059] The term "hydrogen bond crosslinking gelling agent" refers to a gelling agent that forms non-covalent or physical crosslinks via hydrogen bonds.

[0060] The hydrogen bonding crosslinking gelling agent may contain one or more of galactomannan, gelatin, agarose, konjac gum, or agar. It is preferable that the hydrogen bonding crosslinking gelling agent contains agar.

[0061] The term "ionic crosslinking gelling agent" refers to a gelling agent that forms non-covalent or physical crosslinks via ionic bonding.

[0062] The ion-crosslinking gelling agent may include low-acylgellan, pectin, kappa-carrageenan, iota-carrageenan, or alginate. It is preferable that the ion-crosslinking gelling agent may include low-acylgellan.

[0063] The gelling agent may contain one or more biopolymers. The biopolymers may be formed from polysaccharides.

[0064] Examples of biopolymers include gellan gum (natural gellan gum, low-acyl gellan gum, high-acyl gellan gum, and low-acyl gellan gum are preferred), xanthan gum, alginate (alginic acid), agar, and guar gum. It is preferable that the composition contains xanthan gum. The composition may contain two biopolymers. The composition may contain three biopolymers. The composition may contain two biopolymers in substantially equal weights. The composition may contain three biopolymers in substantially equal weights.

[0065] The gel composition may further contain a thickening agent. Surprisingly, thickening agents combined with hydrogen-bonding crosslinking gelling agents appear to support solid media and maintain the gel composition even when it contains high levels of glycerol.

[0066] The term "thickener" refers to a compound that, when uniformly added in an amount of 0.3 weight percent to a mixture of 50 weight percent water and 50 weight percent glycerol at 25°C, increases viscosity without causing gel formation, causing the mixture to remain in a fluid state or to stay fluid.

[0067] The gel composition preferably contains a thickening agent in an amount ranging from about 0.2% to about 5% by weight, or about 0.5% to about 3% by weight, or about 0.5% to about 2% by weight, or about 1% to about 2% by weight.

[0068] The thickener may contain one or more of the following: xanthan gum, carboxymethylcellulose, microcrystalline cellulose, methylcellulose, gum arabic, guar gum, lambda carrageenan, or starch. It is preferable that the thickener contains xanthan gum.

[0069] The gel composition may further contain divalent cations. Preferably, the divalent cations include calcium ions such as calcium lactate in the solution. Divalent cations (such as calcium ions) can assist in gel formation in compositions containing gelling agents, such as ion-crosslinking gelling agents. Ionic effects may assist in gel formation. Divalent cations may be present in the gel composition in the range of about 0.1 to about 1 weight percent, or about 0.5 weight percent.

[0070] The gel composition may further contain an acid. The acid may contain a carboxylic acid. The carboxylic acid may contain a ketone group. Preferably, the carboxylic acid may contain a ketone group having less than 10 carbon atoms, such as levulinic acid or lactic acid, or less than 6 carbon atoms or less than 4 carbonate atoms. Preferably, this carboxylic acid has three carbon atoms (such as lactic acid).

[0071] The gel composition preferably contains some water. The gel composition is more stable when it contains some water.

[0072] Preferably, the gel composition contains about 8% to about 32% by weight of water, or about 15% to about 25% by weight of water, or about 18% to about 22% by weight of water, or about 20% by weight of water.

[0073] The solid aerosol generating substrate may be provided in any suitable form. The capsule preferably contains multiple particles of the solid aerosol generating substrate. For example, the capsule may contain multiple beads, pellets, granules, flakes, fragments, or flaks of the aerosol generating substrate.

[0074] In certain embodiments, the maximum dimension of each particle is preferably at least 0.05 mm, more preferably at least 0.1 mm, more preferably at least 0.15 mm, more preferably at least 0.2 mm, more preferably at least 0.25 mm, more preferably at least 0.5 mm, more preferably at least 0.75 mm, and more preferably at least 1 mm. The maximum dimension of each particle is preferably 10 mm or less, more preferably 9 mm or less, more preferably 8 mm or less, more preferably 6 mm or less, and more preferably 5 mm or less. Providing relatively large particles within these ranges may be preferable when holes are provided in the capsule wall for forming air intakes and outlets, as described below. The relatively large maximum dimension of the particles then ensures that the particles are not lost through the holes in the capsule wall.

[0075] The maximum dimension of a particle corresponds to its maximum outer diameter. If the particle is substantially spherical, the maximum dimension of the particle corresponds to its diameter.

[0076] In these embodiments, the capsule preferably contains at least two particles of the aerosol-generating substrate, more preferably at least five particles, more preferably at least ten particles, more preferably at least 20 particles, and more preferably at least 30 particles. The capsule may contain up to 200 particles.

[0077] In other embodiments, the solid aerosol generating substrate may be in the form of a powder having more smaller particles. For example, in such embodiments, the powder may be formed from particles having a D50 particle size of 50 to 80 micrometers, 50 to 75 micrometers, 55 to 75 micrometers, 55 to 70 micrometers, or 60 to 70 micrometers.

[0078] As used herein in connection with the present invention, the term "D50 particle size" refers to the median particle size of a particulate material or powder. The D50 particle size is the particle size that divides the distribution in half, with half of the particles being larger than the D50 particle size and the other half being smaller than the D50 particle size. The particle size distribution can be determined by laser diffraction. For example, the particle size distribution can be determined by laser diffraction using a Malvern Mastersizer 3000 laser diffraction particle size analyzer, according to the manufacturer's instructions.

[0079] The powder may be formed from particles having a D95 particle size of 80 to 130 micrometers, 90 to 125 micrometers, 100 to 120 micrometers, or 110 to 120 micrometers.

[0080] As used herein in connection with the present invention, the term "D95 particle size" means a particle size in which 95 percent of the mass of particles have a particle size less than this value.

[0081] The powder may be formed from particles having a maximum diameter of 50 to 250 micrometers, 80 to 225 micrometers, or 100 to 125 micrometers.

[0082] In embodiments where the capsule contains multiple particles, the mass of each particle is preferably at least 0.05 micrograms, more preferably at least 0.1 micrograms, more preferably at least 0.2 micrograms, more preferably at least 0.3 micrograms, more preferably at least 0.4 micrograms, more preferably at least 0.5 micrograms, more preferably at least 0.6 micrograms, more preferably at least 0.7 micrograms, more preferably at least 0.8 micrograms, more preferably at least 0.9 micrograms, more preferably at least 1 microgram, more preferably at least 10 micrograms, more preferably at least 100 micrograms, more preferably at least 200 micrograms, more preferably at least 500 micrograms, and more preferably at least 1 milligram. The mass of each particle is preferably 600 milligrams or less, more preferably 500 milligrams or less, more preferably 400 milligrams or less, more preferably 300 milligrams or less, more preferably 200 milligrams or less, more preferably 100 milligrams or less, more preferably 50 milligrams or less, and more preferably 10 milligrams or less.

[0083] Alternatively, the solid aerosol generating substrate may be in the form of one or more sheets. As used herein in relation to the present invention, the term “sheet” refers to a layered element having a width and length substantially greater than its thickness.

[0084] One or more sheets as described herein may be crimped, folded, gathered, and pleated. One or more sheets may be cut into strands.

[0085] As described above, in the aerosol generating article of the present invention, the solid aerosol generating substrate is contained within a capsule. The capsule includes an outer wall that defines an internal cavity containing the solid aerosol generating substrate.

[0086] The capsule outer wall can be formed from any suitable material. Preferably, the capsule outer wall is formed from an impermeable material, and most preferably from an impermeable polymer material. This ensures that air does not pass through the capsule outer wall except through holes specifically provided for airflow during use. Therefore, the airflow through the capsule during use can be effectively controlled.

[0087] The capsule outer wall may contain polymeric or cellulosic materials. For example, the capsule outer wall may be made of one or more nicotine-compatible polymers, including medical-grade polymers such as ALTUGLAS® medical resin polymethyl methacrylate (PMMA), Chevron Phillips K-Resin® styrene-butadiene copolymer (SBC), Arkema specialty performance polymers Pebax®, Rilsan®, and Rilsan® Clear, DOW (Health+®) low-density polyethylene (LDPE), DOW® LDPE91003, DOW® LDPE91020 (MFI2.0; density 923), ExxonMobil® polypropylene (PP) PP1013H1, PP1014H1, and PP9074MED, and Trinseo CALIBRE® polycarbonate (PC) 2060-SERIES.

[0088] Alternatively, the capsule outer wall may be formed from one or more materials selected from polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polyethylene terephthalate (PET), polylactic acid (PLA), cellulose acetate (CA), gelatin, and hydroxypropyl methylcellulose (HPMC).

[0089] In embodiments where the capsule wall is intended to be penetrated by a heating element or penetrating element within the aerosol generator, as described below, the capsule wall should be formed of a penetrating or fragile material. The upstream end wall of the capsule may optionally include one or more weak lines or weak regions positioned to facilitate the insertion of a heating element through the capsule wall during use.

[0090] The capsule is preferably spherical-cylindrical in shape, with the cylindrical portion defined by a cylindrical wall and each end of the cylindrical portion having rounded hemispherical end walls. This type of capsule is commonly used in the pharmaceutical industry. Alternatively, the capsule may be spherical or oval in shape.

[0091] The capsule is preferably a two-part capsule having two separate parts that, when fitted together, close the capsule and hold its contents. The two separate parts may be fitted together by friction without adhesive. Alternatively, the two parts may be sealed together using adhesive.

[0092] The capsule preferably comprises a first portion and a second portion, the second portion having a smaller outer diameter than the first portion so that the end of the second portion can be inserted into the open end of the first portion to close the capsule. When the capsule is fitted into a hollow tubular element, the second portion of the capsule is preferably provided downstream of the first portion.

[0093] In such embodiments, the outer diameters of the first and second portions of the capsule can be adapted such that only the second portion of the capsule can be received within the hollow tubular element. The outer diameter of the first portion of the capsule is adapted to be larger than the inner diameter of the hollow tubular element such that the first portion of the capsule cannot be received within the hollow tubular element and remains outside the hollow tubular element at its upstream end. The second portion of the capsule is preferably held within the hollow tubular element by friction fitting. The first portion prevents the capsule from being further pushed into the hollow tubular element.

[0094] Alternatively, in such embodiments, the capsule may be completely inserted into a hollow tubular element, and the outer diameters of the first and second portions of the capsule may be fitted such that the outer diameter of the second portion is smaller than the inner diameter of the hollow tubular element. This provides space between the second portion of the capsule and the wall of the hollow tubular element, allowing airflow around the second portion of the capsule. Such arrangements may be beneficial in embodiments where it is desirable to position the air outlet on the cylindrical wall of the capsule, as described below. The outer diameter of the first portion of the capsule is preferably fitted so that the first portion of the capsule is held in place within the hollow tubular article by friction fitting. Alternatively, the first portion of the capsule may be held in place by a suitable adhesive. Either of these arrangements preferably substantially prevents airflow around the first portion of the capsule downstream of the second portion of the capsule.

[0095] The internal cavity of the capsule has a volume of at least 250 cubic millimeters, corresponding to 0.25 millimeters. This corresponds to the internal volume, or capacity, of the capsule. Preferably, the internal cavity of the capsule has a volume of at least 400 cubic millimeters (0.4 milliliters), more preferably at least 500 cubic millimeters (0.5 milliliters), and more preferably at least 600 cubic millimeters (0.6 milliliters). The internal cavity of the capsule may be less than 2000 cubic millimeters (2 milliliters), or less than 1500 cubic millimeters (1.5 milliliters), or less than 1000 cubic millimeters (1 milliliter). For example, standard capsule sizes 000, 00, 0, 0, 1, 2, and 3 may be suitable.

[0096] The capsule preferably has a length of at least 10 millimeters, more preferably at least 12 millimeters, more preferably at least 15 millimeters, and more preferably at least 18 millimeters. The length of the capsule is preferably less than 30 millimeters, more preferably less than 28 millimeters, and more preferably less than 25 millimeters. For example, the capsule length may be between 10 millimeters and 30 millimeters, or between 12 millimeters and 28 millimeters, or between 15 millimeters and 25 millimeters, or between 18 millimeters and 25 millimeters. The length of the capsule may be about 20 millimeters.

[0097] Preferably, the capsule has a maximum diameter of at least 5 mm, more preferably at least 5.5 mm, more preferably at least 6 mm, and more preferably at least 6.5 mm. Preferably, the maximum diameter of the capsule is less than 9 mm, more preferably less than 8.5 mm, more preferably less than 8 mm, and more preferably less than 7.5 mm. For example, the maximum diameter of the capsule may be between 5 mm and 9 mm, or between 5.5 mm and 8.5 mm, or between 6 mm and 6 mm, or between 6.5 mm and 7.5 mm. The maximum diameter of the capsule may be about 7 mm.

[0098] The internal cavity of the capsule preferably contains at least 50 milligrams of solid aerosol generating substrate, more preferably at least 100 milligrams of solid aerosol generating substrate, and more preferably at least 150 milligrams of solid aerosol generating substrate. The internal cavity may contain up to 1000 milligrams of solid aerosol generating substrate, or up to 750 milligrams of solid aerosol generating substrate, or up to 500 milligrams of solid aerosol generating substrate, or up to 250 milligrams of solid aerosol generating substrate. For example, the internal cavity of the capsule may contain 50 to 1000 milligrams of solid aerosol generating substrate, or 100 to 750 milligrams of solid aerosol generating substrate, or 150 to 500 milligrams of solid aerosol generating substrate, or 150 to 250 milligrams of solid aerosol generating substrate.

[0099] According to the present invention, the density of the solid aerosol generating substrate inside the capsule is at least 0.1 milligrams / cubic millimeter of the internal cavity. As defined above, this corresponds to the total weight of the solid aerosol generating substrate inside the capsule divided by the total volume of the internal cavity. Preferably, the density of the solid aerosol generating substrate inside the capsule is at least 0.12 milligrams / cubic millimeter of the internal cavity, more preferably at least 0.15 milligrams / cubic millimeter of the internal cavity, more preferably at least 0.18 milligrams / cubic millimeter of the internal cavity, more preferably at least 0.2 milligrams / cubic millimeter, more preferably at least 0.22 milligrams / cubic millimeter, more preferably at least 0.25 milligrams / cubic millimeter, more preferably at least 0.28 milligrams / cubic millimeter, more preferably at least 0.3 milligrams / cubic millimeter, more preferably at least 0.32 milligrams / cubic millimeter, more preferably at least 0.35 milligrams / cubic millimeter, more preferably at least 0.38 milligrams / cubic millimeter, and more preferably at least 0.4 milligrams / cubic millimeter.

[0100] Preferably, the density of the solid aerosol generating substrate inside the capsule is less than 2 milligrams / cubic millimeter of the internal cavity, more preferably less than 1.9 milligrams / cubic millimeter of the internal cavity, more preferably less than 1.8 milligrams / cubic millimeter, more preferably less than 1.7 milligrams / cubic millimeter, more preferably less than 1.6 milligrams / cubic millimeter, more preferably less than 1.5 milligrams / cubic millimeter, more preferably less than 1.4 milligrams / cubic millimeter, more preferably less than 1.3 milligrams / cubic millimeter, more preferably less than 1.2 milligrams / cubic millimeter, more preferably less than 1.1 milligrams / cubic millimeter, and more preferably less than 1 milligram / cubic millimeter.

[0101] For example, the density of the solid aerosol generating substrate inside the capsule is 0.1 mg / m³ to 2 mg / m³ of the internal cavity, or 0.12 mg / m³ to 1.9 mg / m³ of the internal cavity, or 0.15 mg / m³ to 1.8 mg / m³ of the internal cavity, or 0.18 mg / m³ to 1.7 mg / m³ of the internal cavity, or 0.2 mg / m³ to 1.6 mg / m³ of the internal cavity, or 0.22 mg / m³ to 1.5 mg / m³ of the internal cavity, or 0.25 mg / m³ of the internal cavity. This may correspond to grams / cubic millimeter to 1.4 milligrams / cubic millimeter, or 0.28 milligrams / cubic millimeter to 1.3 milligrams / cubic millimeter for internal cavities, or 0.3 milligrams / cubic millimeter to 1.2 milligrams / cubic millimeter for internal cavities, or 0.32 milligrams / cubic millimeter to 1.1 milligrams / cubic millimeter for internal cavities, or 0.35 milligrams / cubic millimeter to 1 milligram / cubic millimeter for internal cavities, or 0.38 milligrams / cubic millimeter to 1 milligram / cubic millimeter for internal cavities, or 0.4 milligrams / cubic millimeter to 1 milligram / cubic millimeter for internal cavities.

[0102] The filling rate of the capsule with the solid aerosol generating substrate is preferably at least 50 percent, more preferably at least 60 percent, and more preferably at least 70 percent. A filling rate of less than 90 percent is preferable. The filling rate corresponds to the proportion of the internal cavity of the capsule occupied by the solid aerosol generating substrate. It may be advantageous to retain some empty space within the internal cavity to allow airflow through the internal cavity and to enable uniform heating of the solid aerosol generating substrate.

[0103] The capsule should be adapted so that one or more airflow paths are provided through the capsule during heating. This allows aerosols generated from the aerosol generating substrate to be drawn out through the aerosol generating article and delivered to the consumer. The capsule may be sealed and airtight in the initial stage so that when the aerosol generating article is inserted into the aerosol generating device, airflow paths are created, for example, through the insertion of an internal heating element or by penetrating elements that penetrate the outer wall of the capsule.

[0104] Alternatively, and more preferably, the capsule includes at least one air intake and at least one air outlet within the outer wall of the capsule. The at least one air intake and at least one air outlet define one or more airflow paths through the internal cavity of the capsule. The at least one air outlet is provided downstream of the at least one air intake.

[0105] The capsule preferably includes multiple air intakes. For example, the capsule may include 2 to 6 air intakes.

[0106] The capsule preferably includes multiple air outlets. For example, the capsule may include 2 to 6 air outlets. The number of air outlets may be the same as or different from the number of air intakes. It may be advantageous to provide more air outlets than air intakes, as the air outlets need to allow aerosols generated inside the capsule to escape from the capsule into the hollow tubular element.

[0107] The number and size of the air intakes and outlets can be adjusted to control the airflow through the capsule and the draw resistance (RTD) of the aerosol-generating article. In certain embodiments, the capsule provides the primary source of RTD within the article, and therefore the overall RTD of the aerosol-generating article is likely to be highly dependent on the RTD of the capsule.

[0108] Each air intake and outlet is preferably in the form of a hole passing through the outer wall of the capsule. Each hole is preferably spherical, but other shapes may also be appropriate. The diameter of each hole should be large enough, for example, that the hole cannot be easily blocked by dust. However, the diameter of each hole should also be adapted according to the form and properties of the solid aerosol generating substrate so that the solid aerosol generating substrate is not lost from the internal cavity through the hole.

[0109] Each hole forming the air intake or air outlet preferably has a diameter of at least 0.2 mm, more preferably at least 0.25 mm, more preferably at least 0.3 mm, more preferably at least 0.35 mm, more preferably at least 0.4 mm, and more preferably at least 0.5 mm. The diameter of each hole may be less than 2 mm, or less than 1.8 mm, or less than 1.6 mm, or less than 1.4 mm, or less than 1.2 mm, or less than 1 mm, or less than 0.9 mm, or less than 0.8 mm. For example, the diameter of each hole may be 0.2 mm to 2 mm, or 0.25 mm to 1.8 mm, or 0.3 mm to 1.6 mm, or 0.35 mm to 1.4 mm, or 0.4 mm to 1.2 mm, or 0.45 mm to 1 mm, or 0.5 mm to 0.9 mm, or 0.5 mm to 0.8 mm.

[0110] If multiple air intakes or outlets are provided, each hole should be spaced sufficiently apart so that its presence does not adversely affect the structural integrity of the capsule. For example, it is preferable that the holes be spaced at least 1 millimeter apart from each other.

[0111] At least one air outlet is preferably located at least 5 millimeters downstream of at least one air intake, more preferably at least 8 millimeters downstream of at least one air intake, and more preferably at least 10 millimeters downstream of at least one air intake. This spacing allows for maximizing the length of the airflow path through the capsule.

[0112] Preferably, at least one air outlet is located at the downstream end of the capsule. If the capsule has a conventional capsule shape with an elongated cylindrical body and rounded end walls, it is preferable that at least one air outlet is provided on the downstream end wall.

[0113] At least one air intake may be located at the upstream end of the capsule. For example, if the capsule has the conventional capsule shape as described above, at least one air intake may be provided on the upstream end wall. However, in certain embodiments, it may be advantageous to position at least one air intake at a specific distance downstream of the upstream end. For example, at least one air intake may be provided at least 2 millimeters downstream of the upstream end of the capsule, or at least 3 millimeters downstream of the upstream end of the capsule, or at least 4 millimeters downstream of the upstream end of the capsule, or at least 5 millimeters downstream of the upstream end of the capsule. If multiple air intakes are provided, all air intakes should be provided at least this distance from the upstream end, even if the position of the air intakes along the length of the capsule varies.

[0114] In a preferred embodiment, the capsule includes a cylindrical wall and rounded end walls at the upstream and downstream ends of the cylindrical wall (as in a conventional capsule shape), and at least one air intake may be advantageously provided in the cylindrical wall downstream of the upstream end wall.

[0115] Positioning at least one air intake away from the upstream end of the capsule can be particularly beneficial, as described above, when the solid aerosol-generating substrate is in the form of a gel composition or any other type of substrate that melts or becomes more viscous upon heating. At least one air intake away from the upstream end of a cavity where molten substrate could accumulate ensures that the risk of aerosol-generating substrate leaking from the capsule is minimized. The risk of the air intake becoming blocked by the aerosol-generating substrate is also reduced.

[0116] The capsule must be mounted within a hollow tubular element, in particular, when at least one air intake is provided on the cylindrical wall of the capsule, such that at least one air intake is not covered or blocked by the wall of the hollow tubular element. There are various suitable methods to achieve this, as described below.

[0117] In certain embodiments, the hollow tubular element includes one or more holes extending through its circumferential wall, positioned to coincide with one or more air intakes on the capsule. In such arrangements, air can pass from the outside of the hollow tubular element through its circumferential wall into at least one air intake.

[0118] In alternative embodiments, the capsule may be mounted within a hollow tubular element such that a portion of the capsule extends from the upstream end of the hollow tubular element, thereby positioning at least one air intake on the outside of the hollow tubular element. Preferably, at least 20 percent of the length of the capsule protrudes from the hollow tubular element, and more preferably at least 30 percent. Preferably, 50 percent or less of the length of the capsule protrudes from the hollow tubular element. Thus, the majority of the capsule is within the hollow tubular element so that the capsule can be held firmly in place. In such embodiments, the hollow tubular element may include a flange or projection extending inward from its inner surface at the downstream end of the capsule to prevent the capsule from being pushed further downstream into the hollow tubular element. For example, the hollow tubular element may include an annular flange extending from its inner surface.

[0119] In a further alternative embodiment, the capsule is provided with an outer diameter smaller than the inner diameter of the hollow tubular element. This arrangement provides a space between the outer surface of the capsule and the inner surface of the hollow tubular element, allowing air to pass between the capsule and the hollow tubular element to at least one air intake. In such embodiments, it is necessary to block the airflow from the upstream end of the hollow tubular element to at least one air outlet within the capsule wall. Thus, the main airflow path is clearly defined through the capsule and not around the outside. This can be achieved, for example, by providing an annular sealing ring around the capsule within the hollow tubular element that seals the space between the capsule and the inner surface of the hollow tubular element at a position downstream of at least one air intake. The annular sealing ring also advantageously helps to hold the capsule in place within the hollow tubular element.

[0120] In this embodiment, the outer diameter of the capsule is preferably at least 0.2 millimeters smaller than the inner diameter of the hollow tubular element, more preferably at least 0.5 millimeters smaller, and more preferably at least 0.8 millimeters smaller. The outer diameter of the capsule may be up to 2 millimeters smaller than the inner diameter of the hollow tubular element.

[0121] In a further alternative embodiment, the inner surface of a hollow tubular element is corrugated at its upstream end to define a plurality of axial channels arranged circumferentially to substantially coincide with at least one air intake. In such an arrangement, air can enter the hollow tubular element through the axial channels defined by the corrugated surface and pass along the capsule to at least one air intake. Preferably, the hollow tubular element is corrugated only along a portion of its length from the upstream end, and not along its entire length. Therefore, it is preferable that the axial channels extend to a position upstream of at least one air outlet so that there is no airflow from the upstream end of the hollow tubular element to at least one air outlet. In this way, the main airflow path is clearly defined through the capsule and not around the outside.

[0122] As described above, in the aerosol generating article of the present invention, a capsule containing a solid aerosol generating substrate is mounted inside a hollow tubular element. The hollow tubular element provides the main structural element of the aerosol generating article. Preferably, the hollow tubular element extends to the downstream end of the aerosol generating article.

[0123] As used herein, the term “hollow tubular element” generally refers to an elongated element that defines a lumen or channel along its longitudinal axis. In particular, the term “tubular” is used below with respect to a tubular element having a substantially cylindrical cross-section and defining at least a channel extending between the upstream and downstream ends of the tubular element. However, it will be understood that alternative shapes of tubular elements (e.g., alternative cross-sectional shapes) may be possible.

[0124] The hollow tubular element has a capsule containing an aerosol-generating substrate mounted at its upstream end, as described above. Furthermore, the hollow tubular element defines an empty cavity downstream of the capsule, extending along part or all of the length of the hollow tubular element. In some embodiments, the empty cavity extends all the way from the capsule to the downstream end of the aerosol-generating article. Thus, in such embodiments, the aerosol-generating article can be formed from only two elements: the capsule and the hollow tubular element. Alternatively, one or more filter segments may be provided within the hollow tubular element at their downstream end, as will be described in more detail below.

[0125] The empty cavity defined within the hollow tubular element downstream of the capsule preferably has a length of at least 10 millimeters, more preferably at least 12 millimeters, and more preferably at least 14 millimeters. The length of the empty cavity may be up to 40 millimeters, or up to 30 millimeters, or up to 25 millimeters. For example, the empty cavity may have a length of 10 to 40 millimeters, or 12 to 30 millimeters, or 14 to 25 millimeters.

[0126] Preferably, the hollow tubular element has a total length of at least 25 mm, more preferably at least 28 mm, more preferably at least 30 mm, more preferably at least 32 mm, and more preferably at least 34 mm. The length of the hollow tubular element may be less than 50 mm, less than 48 mm, less than 45 mm, or less than 42 mm or less than 40 mm. For example, the total length of the hollow tubular element may be 25 mm to 50 mm, or 28 mm to 48 mm, or 30 mm to 45 mm, or 32 mm to 42 mm, or 34 mm to 40 mm.

[0127] The hollow tubular element may have an outer diameter of 5 to 12 mm, for example, 5 to 10 mm, or 6 to 8 mm. In a preferred embodiment, the hollow tubular element has an outer diameter of 7.2 mm plus or minus 10 percent.

[0128] The inner diameter of the hollow tubular element is preferably constant along its length. The lumen or cavity of the hollow tubular element may have any cross-sectional shape. The lumen of the hollow tubular element may have a circular cross-sectional shape.

[0129] Preferably, the inner diameter of the hollow tubular element is at least 5 mm, more preferably at least 5.5 mm, more preferably at least 6 mm, and more preferably at least 6.5 mm. Preferably, the inner diameter of the hollow tubular element is less than 9 mm, more preferably less than 8.5 mm, more preferably less than 8 mm, and more preferably less than 7.5 mm. For example, the inner diameter may be 5 mm to 9 mm, or 5.5 mm to 8.5 mm, or 6 mm to 6 mm, or 6.5 mm to 7.5 mm. The inner diameter may be about 7 mm.

[0130] The hollow tubular element preferably has a wall thickness of at least 100 micrometers, more preferably at least 150 micrometers, more preferably at least 200 micrometers, more preferably at least 250 micrometers, and more preferably at least 500 micrometers. The wall thickness of the hollow tubular element may be less than 2 millimeters, preferably less than 1.5 millimeters, and even more preferably less than 1.25 mm. The wall thickness of the hollow tubular element may be less than 1 millimeter. For example, the wall thickness of the hollow tubular element may be 100 micrometers to 2 millimeters, or 150 micrometers to 1.5 millimeters, or 200 micrometers to 1.25 millimeters, or 250 micrometers to 1 millimeter, or 500 micrometers to 1 millimeter.

[0131] The hollow tubular element may contain a paper-based material. The hollow tubular element may contain at least one layer of paper. The paper may be very rigid paper. The paper may be crimped paper, such as crimped heat-resistant paper or crimped sulfuric acid paper. Advantageously, the crimped paper may form one or more airflow channels extending around the outside of the capsule. One or more airflow channels may be particularly advantageous in embodiments in which the capsule includes at least one of an air intake and an air outlet on the cylindrical wall of the capsule.

[0132] Preferably, the hollow tubular element is formed from cardboard. The hollow tubular element may be a cardboard tube. Advantageously, cardboard is a cost-effective material that provides a balance between being deformable to provide ease of inserting articles into the aerosol generator and being rigid enough to provide proper engagement of articles with the inside of the device. Thus, the cardboard tube may provide good resistance to deformation or compression during use.

[0133] The hollow tubular element may be a paper tube. The hollow tubular element may be a tube formed from spirally wound paper. The hollow tubular element may be formed from multiple layers of paper. The paper may have a basis weight of at least about 50 grams per square meter, at least about 60 grams per square meter, at least about 70 grams per square meter, or at least about 90 grams per square meter.

[0134] The hollow tubular element may contain polymer materials. For example, the hollow tubular element may contain a polymer film. The polymer film may contain a cellulose film. The hollow tubular element may contain low-density polyethylene (LDPE) or polyhydroxyalkanoate (PHA) fibers. The hollow tubular element may contain cellulose acetate tow.

[0135] If the hollow tubular element contains cellulose acetate tow, the cellulose acetate tow may have about 2 to about 4 denier per filament and about 25 to about 40 total denier.

[0136] In the aerosol generating article according to the present invention, the hollow tubular element preferably provides a negligible level of drawdown resistance (RTD). The term "negligible level of RTD" is used to describe an RTD of less than 1 mmH2O per 10 mm length hollow tubular element or hollow tubular element, preferably less than 0.4 mmH2O per 10 mm length hollow tubular element or hollow tubular element, and more preferably less than 0.1 mmH2O per 10 mm length hollow tubular element or hollow tubular element.

[0137] The RTD of the hollow tubular element is preferably about 10 mmH2O or less. More preferably, the RTD of the hollow tubular element is about 5 mmH2O or less. Even more preferably, the RTD of the hollow tubular element is about 2.5 mmH2O or less. Even more preferably, the RTD of the hollow tubular element is about 2 mmH2O or less. Even more preferably, the RTD of the hollow tubular element is about 1 mmH2O or less.

[0138] The RTD of the hollow tubular element may be at least 0 mmH2O, or at least about 0.25 mmH2O, or at least about 0.5 mmH2O, or at least about 1 mmH2O.

[0139] In some preferred embodiments, the RTD of the hollow tubular element is about 0 mmH2O to about 10 mmH2O, preferably about 0.25 mmH2O to about 10 mmH2O, and more preferably about 0.5 mmH2O to about 10 mmH2O. In other embodiments, the RTD of the hollow tubular element is about 0 mmH2O to about 5 mmH2O, preferably about 0.25 mmH2O to about 5 mmH2O, and more preferably about 0.5 mmH2O to about 5 mmH2O. In yet another embodiment, the RTD of the hollow tubular element is about 1 mmH2O to about 5 mmH2O. In a further embodiment, the RTD of the hollow tubular element is about 0 mmH2O to about 2.5 mmH2O, preferably about 0.25 mmH2O to about 2.5 mmH2O, and more preferably about 0.5 mmH2O to about 2.5 mmH2O. In further embodiments, the RTD of the hollow tubular element is about 0 mmH2O to about 2 mmH2O, preferably about 0.25 mmH2O to about 2 mmH2O, and more preferably about 0.5 mmH2O to about 2 mmH2O. In one particularly preferred embodiment, the RTD of the hollow tubular element is about 0 mmH2O.

[0140] The aerosol-generating article according to the present invention may further include a downstream filter segment installed within the hollow tubular element at the downstream end of the hollow tubular element. The downstream filter segment may extend to the downstream end of the hollow tubular element. The downstream end of the downstream filter segment may define the downstream end of the aerosol-generating article. Including the downstream filter segment within the hollow tubular element may be useful in providing the aerosol-generating article with a desired level of RTD (Ready-to-Dose).

[0141] The downstream filter segment is preferably located downstream of the capsule, and preferably there is a gap in the longitudinal direction between the capsule and the downstream filter segment so that a cavity is defined between them. The downstream filter segment is preferably located at least 5 millimeters downstream from the downstream end of the capsule, more preferably at least 8 millimeters downstream, more preferably at least 10 millimeters downstream, and more preferably at least 15 millimeters downstream. The downstream filter segment is preferably located less than 30 millimeters downstream from the downstream end of the capsule, and more preferably less than 25 millimeters downstream. The distance defined between the downstream end of the capsule and the downstream filter segment corresponds to the length of the cavity between the capsule and the downstream filter segment.

[0142] The downstream filter segment is preferably a solid plug, which may also be described as a "plain" plug and is non-tubular. Therefore, the filter segment preferably has a substantially uniform cross-sectional area.

[0143] The downstream filter segment is formed of a fibrous filter material. The fibrous filter material may be for filtering aerosols generated from the aerosol generating substrate. Suitable fibrous filter materials will be known to those skilled in the art. Particularly preferably, at least one downstream filter segment includes a cellulose acetate filter segment formed from cellulose acetate tow.

[0144] The downstream filter segment may optionally contain flavoring agents, which can be provided in any preferred form. For example, the downstream filter segment may contain one or more capsules, beads, or granules of the flavoring agent, or one or more flavored threads or filaments.

[0145] The downstream filter segment preferably has a low particle filtration efficiency.

[0146] The downstream filter segment preferably has an outer diameter approximately equal to the inner diameter of the hollow tubular element, so that the downstream filter segment is held within the hollow tubular element by friction fitting.

[0147] Preferably, the outer diameter of the downstream filter segment is 5 mm to 12 mm, more preferably 6 mm to 10 mm, and more preferably 7 mm to 8 mm.

[0148] Unless otherwise specified, the draw resistance (RTD) of a component or aerosol-generating article shall be measured in accordance with ISO 6565-2015. RTD refers to the pressure required to force air through the entire length of the component. The terms “pressure drop” or “draw resistance” of a component or article may also refer to “resistance to draw.” These terms generally refer to the fact that the measurement in accordance with ISO 6565-2015 is successfully performed under a test of a volumetric flow rate of 17.5 ml per second at the output or downstream end of the measured component, at a temperature of 22 degrees Celsius, a pressure of 101 kPa (approximately 760 Torr), and a relative humidity of 60%. The conditions for smoking and the specifications of the smoking machine are presented in ISO standard 3308 (ISO 3308:2000). The atmosphere for adjustment and testing is presented in ISO standard 3402 (ISO 3402:1999).

[0149] The draw-out resistance (RTD) of the downstream filter segment may be at least 0 mmH2O, or at least 3 mmH2O, or at least 6 mmH2O.

[0150] The RTD of the downstream filter segment may be 12 mmH2O or less, or 11 mmH2O or less, or 10 mmH2O or less.

[0151] As described above, the downstream filter segment may be formed from a fibrous material. The downstream filter segment may be formed from a porous material. The downstream filter segment may be formed from a biodegradable material. The downstream filter segment may be formed from a cellulose material such as cellulose acetate. For example, the downstream filter segment may be formed from a bundle of cellulose acetate fibers having 10 to 15 denier per filament. For example, the downstream filter segment may be formed from a relatively low-density cellulose acetate tow, such as cellulose acetate tow containing fibers of 12 denier per filament.

[0152] The downstream filter segment may be formed from a polylactic acid-based material. The downstream filter segment may also be formed from a bioplastic material, preferably a starch-based bioplastic material. The downstream filter segment may be manufactured by injection molding or extrusion molding. Bioplastic materials are advantageous because they can provide a downstream filter segment structure that is easy and inexpensive to manufacture, with a specific complex cross-sectional profile that may include multiple relatively large airflow channels extending through the downstream filter segment material, providing suitable RTD properties.

[0153] The length of the downstream filter segment may be at least 5 millimeters, or at least 8 millimeters, or at least 10 millimeters. The length of the downstream filter segment may be less than 20 millimeters, or less than 15 millimeters, or less than 12 millimeters. For example, the length of the downstream filter segment may be between 5 millimeters and 20 millimeters, or between 8 millimeters and 15 millimeters, or between 8 millimeters and 12 millimeters, or between 10 millimeters and 12 millimeters.

[0154] In an alternative embodiment of the present invention, the downstream filter segment may be provided downstream of the hollow tubular element. The downstream filter segment may extend between the hollow tubular element and the downstream end of the aerosol-generating article. In such embodiments, the downstream filter segment may be connected to the hollow tubular element by a chipping wrapper.

[0155] The overall RTD of an aerosol-generating article may be at least 1 milliH2O. For example, the overall RTD of an aerosol-generating article may be at least 2 milliH2O, at least 3 milliH2O, at least 4 milliH2O, at least 5 milliH2O, at least 6 milliH2O, at least 7 milliH2O, at least 8 milliH2O, at least 9 milliH2O, at least 10 milliH2O, at least 15 milliH2O, at least 20 milliH2O, at least 30 milliH2O, at least 40 milliH2O, or at least 50 milliH2O.

[0156] The overall RTD of an aerosol-generating article may be 180 mmH2O or less. For example, the overall RTD of an aerosol-generating article may be 170 mmH2O or less, 160 mmH2O or less, 150 mmH2O or less, or 140 mmH2O or less.

[0157] The overall RTD of an aerosol-generating article may range from 1 mmH2O to 180 mmH2O. For example, the overall RTD of an aerosol-generating article may range from 5 mmH2O to 170 mmH2O, 10 mmH2O to 160 mmH2O, 20 mmH2O to 150 mmH2O, or 50 mmH2O to 140 mmH2O.

[0158] The aerosol-generating article according to the present invention may have an overall length of at least 40 millimeters, or at least 50 millimeters, or at least 60 millimeters.

[0159] The aerosol-generating article of the present invention may have a total length of 90 mm or less, 85 mm or less, or 80 mm or less.

[0160] In some embodiments, the total length of the aerosol-generating article is preferably 40 to 70 millimeters, more preferably 45 to 70 millimeters. In other embodiments, the total length of the aerosol-generating article is preferably 40 to 60 millimeters, more preferably 45 to 60 millimeters. In further embodiments, the total length of the aerosol-generating article is preferably 40 to 50 millimeters, more preferably 45 to 50 millimeters. In exemplary embodiments, the total length of the aerosol-generating article is about 45 millimeters.

[0161] The aerosol-generating article may have an outer diameter of at least 5 millimeters, at least 6 millimeters, or at least 7 millimeters.

[0162] The aerosol-generating article may have an outer diameter of approximately 12 mm or less, approximately 10 mm or less, or approximately 8 mm or less.

[0163] In some embodiments, the aerosol-generating article has an outer diameter of about 5 mm to about 12 mm, preferably about 6 mm to about 12 mm, and more preferably about 7 mm to about 12 mm. In other embodiments, the aerosol-generating article has an outer diameter of about 5 mm to about 10 mm, preferably about 6 mm to about 10 mm, and more preferably about 7 mm to about 10 mm. In further embodiments, the aerosol-generating article has an outer diameter of about 5 mm to about 8 mm, preferably about 6 mm to about 8 mm, and more preferably about 7 mm to about 8 mm. In other embodiments, the aerosol-generating article has an outer diameter of less than 7 mm.

[0164] The outer diameter of an aerosol-generating article may be substantially constant along its entire length. Alternatively, different parts of the aerosol-generating article may have different outer diameters.

[0165] The present invention relates to an aerosol generating system comprising an aerosol generating article according to the invention as defined above, and an aerosol generating device comprising a heating chamber for receiving the aerosol generating article, and a heating element provided inside or around the heating chamber.

[0166] The aerosol generator has a distal end and an oral end. The aerosol generator may comprise a body. The body or housing of the aerosol generator may define a device cavity at the oral end of the device for removably receiving an aerosol generating article. The aerosol generator may comprise a heating element or heater for heating the aerosol generating substrate when the aerosol generating article is received in the device cavity.

[0167] The device cavity may also be called the heating chamber of the aerosol generator. The device cavity may extend between a distal end and a mouth (or proximal) end. The distal end of the device cavity may be a closed end, and the mouth (or proximal) end may be an open end. The aerosol generating article may be inserted into the device cavity or heating chamber through the open end of the device cavity. The device cavity may be cylindrical in shape to accommodate the same shape as the aerosol generating article.

[0168] The expression "internal acceptance" may refer to the fact that a component or element is fully or partially accepted within another component or element. For example, the expression "an aerosol-generating article is accepted within the device cavity" means that the aerosol-generating article is fully or partially accepted within the device cavity of the aerosol-generating article. When an aerosol-generating article is accepted within the device cavity, the aerosol-generating article may be in contact with the distal end of the device cavity. When an aerosol-generating article is accepted within the device cavity, the aerosol-generating article may be substantially close to the distal end of the device cavity. The distal end of the device cavity may be defined by an end wall.

[0169] The length of the cavity in the device may be 15 mm to 80 mm, or 20 mm to 70 mm, or 25 mm to 60 mm, or 25 mm to 50 mm.

[0170] The length of the cavity in the device may be 25 to 29 millimeters, 26 to 29 millimeters, or 27 to 28 millimeters.

[0171] When the aerosol-generating article is received into the device cavity, it is preferable that the capsule be completely contained within the device cavity in order to optimize the heating of the solid aerosol-generating substrate inside the capsule. Therefore, it is preferable that the length of the device cavity be longer than the length of the capsule.

[0172] The diameter of the device cavity may be 4 mm to 10 mm. The diameter of the device cavity may be 5 mm to 9 mm. The diameter of the device cavity may be 6 mm to 8 mm. The diameter of the device cavity may be 6 mm to 7 mm.

[0173] The diameter of the device cavity may be substantially the same as, or larger than, the diameter of the aerosol generating article. The diameter of the device cavity may be the same as the diameter of the aerosol generating article in order to establish a tight fit with the aerosol generating article.

[0174] The device cavity may be configured to establish a tight fit with the aerosol generating article received within the device cavity. A tight fit may refer to a sliding fit. The aerosol generating device may include a peripheral wall. Such a peripheral wall may define a device cavity or a heating chamber. The peripheral wall defining the device cavity may be configured to engage in a tight fit with the aerosol generating article received within the device cavity such that, when received within the device, there is substantially no gap or empty space between the peripheral wall defining the device cavity and the aerosol generating article.

[0175] Such airtight fittings can establish an airtight fit or configuration between the device cavity and the aerosol-generating article received therein.

[0176] In such an airtight configuration, there is virtually no gap or empty space between the peripheral wall defining the device cavity and the aerosol-generating article through which air flows.

[0177] A tight fit with the aerosol-generating article may be established along the entire length of the device cavity or along a portion of the length of the device cavity.

[0178] An aerosol generator may include airflow channeling extending between a channel inlet and a channel outlet. The airflow channel may be configured to establish fluid communication between the inside of the device cavity and the outside of the aerosol generator. The airflow channel of the aerosol generator may be defined within the housing of the aerosol generator to enable fluid communication between the inside of the device cavity and the outside of the aerosol generator. When an aerosol-generating article is received in the device cavity, the airflow channel may be configured to provide air flowing into the article to deliver the generated aerosol to a user who inhales it from the mouth end of the article.

[0179] The airflow channels of the aerosol generator may be defined within or by the peripheral walls of the housing of the aerosol generator. In other words, the airflow channels of the aerosol generator may be defined within the thickness of the peripheral walls, by the inner surfaces of the peripheral walls, or a combination of both. The airflow channels may be partially defined by the inner surfaces of the peripheral walls, or partially defined within the thickness of the peripheral walls. The inner surfaces of the peripheral walls define the periphery of the device cavity.

[0180] The airflow channel of the aerosol generator may extend from an inlet located at the mouth end or proximal end of the aerosol generator to an outlet located away from the mouth end of the device. The airflow channel may extend along a direction parallel to the longitudinal axis of the aerosol generator.

[0181] The heater may be any suitable type of heater. In this invention, the heater is preferably an external heater that heats the capsule and its contents from the outside. Such an external heater may surround the aerosol generating article when it is inserted into or received in an aerosol generating device.

[0182] Alternatively, the heater may be an elongated heating blade adapted to be inserted into the capsule to internally heat the capsule and its contents.

[0183] The heater may comprise at least one heating element. The at least one heating element may be any suitable type of heating element. In some embodiments, the device comprises only one heating element. In some embodiments, the device comprises multiple heating elements.

[0184] The heating element may be a resistance heating element.

[0185] Suitable materials for forming resistance heating elements include, but are not limited to, semiconductors such as doped ceramics, "conductive" ceramics (e.g., molybdenum disilide), carbon, graphite, metals, metal alloys, and composite materials made of ceramic and metal materials. Such composite materials may contain doped ceramics or undoped ceramics. An example of a suitable doped ceramic is doped silicon carbide. Examples of suitable metals include titanium, zirconium, tantalum, and platinum group metals. Examples of suitable metal alloys include stainless steel, nickel-containing, cobalt-containing, chromium-containing, aluminum-containing, titanium-containing, zirconium-containing, hafnium-containing, niobium-containing, molybdenum-containing, tantalum-containing, tungsten-containing, tin-containing, gallium-containing, manganese-containing, and iron-containing alloys, as well as nickel, iron, cobalt, stainless steel-based superalloys, Timetal®, and iron-manganese-aluminum alloys.

[0186] In some embodiments, the resistive heating element includes one or more stamped portions of an electrically resistive material (such as stainless steel). Alternatively, at least one resistive heating element may include a heating wire or filament (e.g., Ni-Cr (nickel-chromium), platinum, tungsten, or alloy wire).

[0187] In some embodiments, the heating element includes an electrically insulated substrate, and at least one resistance heating element is provided on the electrically insulated substrate.

[0188] The electrically insulated substrate may include any suitable material. For example, the electrically insulated substrate may include one or more of paper, glass, ceramic, anodized metal, coated metal, and polyimide. The ceramic may include mica, alumina (Al2O3), or zirconia (ZrO2). The electrically insulated substrate preferably has a thermal conductivity of about 40 watts / meter Kelvin or less, preferably about 20 watts / meter Kelvin or less, and ideally about 2 watts / meter Kelvin or less.

[0189] The heater may comprise a heating element including a rigid, electrically insulated substrate having one or more conductive tracks or wires disposed on its surface. Depending on the size and shape of the electrically insulated substrate, it may be permissible to insert the heater directly into the aerosol generating substrate. If the electrically insulated substrate is not sufficiently rigid, the heating element may include further reinforcing means. Current may pass through one or more conductive tracks to heat the heating element and the aerosol generating substrate.

[0190] In some embodiments, the heater comprises an induction heating arrangement. The induction heating device may comprise an inductor coil and a power supply configured to supply a high-frequency oscillating current to the inductor coil. As used herein, a high-frequency oscillating current means an oscillating current having a frequency of about 500 kHz to about 30 MHz. The heater may advantageously comprise a DC / AC inverter for converting the DC current supplied by the DC power supply into an AC current. The inductor coil may be arranged to generate a high-frequency oscillating electromagnetic field upon receiving a high-frequency oscillating current from the power supply. The inductor coil may be positioned to generate a high-frequency oscillating electromagnetic field within a device cavity. In some embodiments, the inductor coil may substantially enclose the device cavity. The inductor coil may extend at least partially along the length of the device cavity.

[0191] The heater may include an induction heating element. The induction heating element may be a susceptor element. The susceptor element may be positioned such that when an aerosol generating article is received in the cavity of the aerosol generator, the oscillating electromagnetic field generated by the inductor coil induces a current within the susceptor element, thereby heating the susceptor element. In these embodiments, the aerosol generator is preferably capable of generating a fluctuating electromagnetic field having a magnetic field strength (H-field strength) of 1 to 5 kiloamperes / meter (kA / m), preferably 2 to 3 kA / m, for example, about 2.5 kA / m. The electrically operated aerosol generator is preferably capable of generating a fluctuating electromagnetic field having a frequency of 1 to 30 MHz, for example, 1 to 10 MHz, for example, 5 to 7 MHz.

[0192] In these embodiments, the susceptor element is preferably located in contact with a solid aerosol generating substrate. In some embodiments, the susceptor element is located inside the aerosol generator. In these embodiments, the susceptor element may be located inside a cavity. The aerosol generator may include only one susceptor element. The aerosol generator may include multiple susceptor elements. In some embodiments, the susceptor element is preferably arranged to heat the outer surface of the aerosol generating substrate.

[0193] The susceptor element may contain appropriate elements.

[0194] In some embodiments, the aerosol generator may comprise at least one resistance heating element and at least one induction heating element. In some embodiments, the aerosol generator may comprise a combination of a resistance heating element and an induction heating element.

[0195] During use, the heater can be controlled to operate within a specified operating temperature range below the maximum operating temperature. The operating temperature range within the heating chamber (or device cavity) is preferably about 150°C to about 300°C. The operating temperature range of the heater may be about 150°C to about 250°C.

[0196] The aerosol generator may be equipped with a power source. The power source may be a DC power source. In some embodiments, the power source is a battery. The power source may be a nickel-metal hydride battery, a nickel-cadmium battery, or a lithium-based battery (e.g., lithium cobalt, lithium iron phosphate, or lithium polymer battery). However, in some embodiments, the power source may be another form of charge storage device, such as a capacitor. The power source may require recharging and may have a capacity that allows for the storage of sufficient energy for one or more user operations, such as one or more aerosol generation experiences.

[0197] The aerosol generator may include a penetration device for penetrating the capsule when the aerosol generating article is inserted into the device cavity. As described above, capsule penetration may be necessary to establish one or more airflow paths through the capsule. [Brief explanation of the drawing]

[0198] [Figure 1] Figure 1 shows a schematic side cross-sectional view of an aerosol generating article according to the first embodiment of the present invention. [Figure 2]Figure 2 shows a schematic side cross-sectional view of an aerosol generating article according to a second embodiment of the present invention. [Figure 3] Figure 3 shows a schematic side cross-sectional view of an aerosol generating article according to a third embodiment of the present invention. [Figure 4] Figure 4 shows a schematic side cross-sectional view of a capsule suitable for use in aerosol-generating articles according to the first, second, and third embodiments. [Modes for carrying out the invention]

[0199] A non-exclusive list of non-limiting embodiments is provided below. One or more features of these embodiments may be combined with one or more features of other embodiments, forms, or aspects described herein.

[0200] Example 1. An aerosol generating article for generating an inhalable aerosol when heated, the aerosol generating article comprising: a hollow tubular element; a capsule attached inside the hollow tubular element at the upstream end of the hollow tubular element, the capsule comprising a capsule outer wall defining an inner cavity; and a solid aerosol generating substrate containing nicotine and an aerosol forming agent, wherein the aerosol forming agent content of the aerosol generating substrate is at least 15 percent by dry weight.

[0201] Example 2. The aerosol-generating article according to Example 1, wherein the internal cavity has a volume of at least 250 cubic millimeters.

[0202] Example 3. The aerosol-generating article according to Example 1 or 2, wherein the bulk density of the solid aerosol-generating substrate inside the capsule is at least 0.1 milligrams per cubic meter of internal cavity.

[0203] Example 4. An aerosol generating article according to any one of Examples 1 to 3, wherein the aerosol generating substrate contains at least 40 weight percent of an aerosol forming body on a dry weight basis.

[0204] Example 5. An aerosol generating article according to any one of Examples 1 to 4, wherein the aerosol generating substrate contains an aerosol forming material of 80% by weight or less on a dry weight basis.

[0205] Example 6. An aerosol-generating article according to any one of Examples 1 to 5, wherein the aerosol-forming body contains glycerol.

[0206] Example 7. An aerosol-generating article according to any one of Examples 1 to 6, wherein the aerosol-generating substrate contains at least 0.5 weight percent nicotine on a dry weight basis.

[0207] Example 8. An aerosol generating article according to any one of Examples 1 to 7, wherein the aerosol generating substrate further comprises one or more carboxylic acids.

[0208] Example 9. An aerosol generating article according to any one of Examples 1 to 8, wherein the aerosol generating substrate is in the form of an aerosol generating film containing a cellulose-based film-forming agent, nicotine, and an aerosol-forming body.

[0209] Example 10. The aerosol generating article according to Example 9, wherein the aerosol generating film further comprises a cellulose-based reinforcing agent.

[0210] Example 11. The aerosol-generating article according to Example 9 or 10, wherein the aerosol-generating film is substantially free of tobacco.

[0211] Example 12. An aerosol generating article according to any one of Examples 1 to 8, wherein the aerosol generating substrate comprises a gel composition containing nicotine, at least one gelling agent, and an aerosol forming body.

[0212] Example 13. The aerosol-generating article according to Example 12, wherein the gel composition is substantially free of tobacco.

[0213] Example 14. The aerosol-generating article according to Example 12 or 13, wherein the gel composition comprises at least 50 weight percent of an aerosol-forming agent.

[0214] Example 15. An aerosol generating article according to any one of Examples 1 to 14, wherein the capsule contains a plurality of particles of a solid aerosol generating substrate.

[0215] Example 16. The aerosol-generating article according to Example 15, wherein the maximum dimension of each particle is at least 0.25 millimeters.

[0216] Example 17. The aerosol-generating article according to Example 15 or 16, wherein the maximum dimension of each particle is 10 millimeters or less.

[0217] Example 18. An aerosol generating article according to any one of Examples 15 to 17, wherein the capsule contains at least 10 particles of aerosol generating substrate.

[0218] Example 19. An aerosol generating article according to any one of Examples 15 to 17, wherein the solid aerosol generating substrate is in powder form.

[0219] Example 20. The aerosol generating article according to Example 19, wherein the powder is formed of particles having a D50 size of 50 micrometers to 80 micrometers.

[0220] Example 21. The aerosol-generating article according to Example 19 or 20, wherein the powder is formed of particles having a maximum diameter of 50 micrometers to 250 micrometers.

[0221] Example 22. An aerosol-generating article according to any one of Examples 15 to 21, wherein the mass of each particle is at least 0.05 micrograms.

[0222] Example 23. The aerosol generating article according to any one of Examples 1 to 14, wherein the solid aerosol generating substrate may be in the form of one or more sheets.

[0223] Example 24. An aerosol-generating article according to any one of Examples 1 to 23, wherein the outer wall of the capsule is formed of an impermeable material.

[0224] Example 25. An aerosol-generating article according to any one of Examples 1 to 24, wherein the outer wall of the capsule contains a polymer material.

[0225] Example 26. An aerosol generating article according to any one of Examples 1 to 25, wherein the outer wall of the capsule is formed of a penetrable material.

[0226] Example 27. An aerosol generating article according to any of Examples 1 to 26, wherein the capsule is in the form of a spherical cylinder.

[0227] Example 28. An aerosol-generating article according to any of Examples 1 to 27, wherein the capsule is a two-part capsule.

[0228] Example 29. The aerosol generating article according to Example 28, wherein the capsule comprises a first part and a second part, the second part having a smaller outer diameter than the first part so that the end of the second part can be inserted into the open end of the first part to close the capsule.

[0229] Example 30. The aerosol generating article according to Example 28 or 29, wherein the outer diameter of the first part of the capsule is greater than the inner diameter of the hollow tubular element, and only the second part of the capsule is attached to the hollow tubular element.

[0230] Example 31. The aerosol generating article according to Example 29, wherein the capsule is fully inserted into a hollow tubular element, the outer diameter of the second portion is smaller than the inner diameter of the hollow tubular element, and a space is provided between the outer surface of the second portion and the inner surface of the hollow tubular element.

[0231] Example 32. An aerosol-generating article according to any of Examples 1 to 31, wherein the capsule has a length of at least 10 millimeters.

[0232] Example 33. An aerosol-generating article according to any of Examples 1 to 32, wherein the capsule has a maximum diameter of at least 5 millimeters.

[0233] Example 34. An aerosol generating article according to any one of Examples 1 to 33, wherein the internal cavity of the capsule contains at least 50 milligrams of a solid aerosol generating substrate.

[0234] Example 35. An aerosol-generating article according to any of Examples 1 to 34, wherein the internal cavity of the capsule has a volume of less than 2000 cubic millimeters.

[0235] Example 36. An aerosol generating article according to any one of Examples 1 to 35, wherein the bulk density of the solid aerosol generating substrate inside the capsule is less than 2 milligrams per cubic millimeter of internal cavity.

[0236] Example 37. An aerosol-generating article according to any of Examples 1 to 36, wherein the capsule filling rate is at least 50 percent.

[0237] Example 38. An aerosol-generating article according to any of Examples 1 to 37, wherein the capsule filling rate is less than 90 percent.

[0238] Example 39. An aerosol-generating article according to any one of Examples 1 to 38, wherein the capsule is adapted so that one or more airflow paths are provided through the capsule during heating.

[0239] Example 40. The aerosol generating article according to Example 39, wherein the capsule is adapted to create an airflow path when the aerosol generating article is inserted into an aerosol generating device.

[0240] Example 41. The aerosol generating article according to Example 39, wherein the capsule includes at least one air intake and at least one air outlet in the outer wall of the capsule.

[0241] Example 42. The aerosol generating article according to Example 41, wherein each of at least one air intake and at least one air outlet is in the form of a hole passing through the outer wall of the capsule.

[0242] Example 43. The aerosol generating article according to Example 42, wherein each hole forming an air intake or air outlet has a diameter of at least 0.2 millimeters.

[0243] Example 44. The aerosol generating article according to Example 42 or 43, wherein each hole forming an air intake or air outlet has a diameter of less than 2 millimeters.

[0244] Example 45. An aerosol-generating article according to any of Examples 42 to 44, wherein the holes are spaced at least 1 millimeter apart from each other.

[0245] Example 46. An aerosol generating article according to any one of Examples 41 to 45, wherein at least one air outlet is preferably at least 5 millimeters downstream of at least one air intake.

[0246] Example 47. An aerosol generating article according to any one of Examples 41 to 46, wherein at least one air outlet is located at the downstream end of the capsule.

[0247] Example 48. An aerosol generating article according to any one of Examples 41 to 47, wherein at least one air intake is located at the upstream end of the capsule.

[0248] Example 49. An aerosol generating article according to any one of Examples 41 to 47, wherein at least one air intake is located at least 2 millimeters downstream of the upstream end of the capsule.

[0249] Example 50. An aerosol generating article according to any one of Examples 41 to 49, wherein the capsule comprises a cylindrical wall and rounded end walls at the upstream and downstream ends of the cylindrical wall, and at least one air intake is provided in the cylindrical wall downstream of the upstream end wall.

[0250] Example 51. An aerosol generating article according to any one of Examples 41 to 50, wherein the capsule is mounted inside a hollow tubular element such that at least one air intake is not covered.

[0251] Example 52. An aerosol generating article according to any one of Examples 41 to 51, wherein the capsule is mounted inside a hollow tubular element such that a portion of the capsule extends from the upstream end of the hollow tubular element, thereby positioning at least one air intake on the outside of the hollow tubular element.

[0252] Example 53. The aerosol-generating article according to Example 52, wherein at least 20 percent of the length of the capsule protrudes from a hollow tubular element.

[0253] Example 54. The aerosol generating article according to Example 52 or 53, wherein a hollow tubular element includes an annular flange extending from the inner surface to prevent the capsule from moving downstream.

[0254] Example 55. An aerosol generating article according to any one of Examples 1 to 51, wherein the capsule is provided with an outer diameter smaller than the inner diameter of the hollow tubular element in order to provide a space between the outer surface of the capsule and the inner surface of the hollow tubular element.

[0255] Example 56. The aerosol-generating article according to Example 55, wherein the outer diameter of the capsule is at least 0.2 millimeters smaller than the inner diameter of the hollow tubular element.

[0256] Example 57. The aerosol generating article according to Example 55 or 56, further comprising an annular sealing ring within a hollow tubular element for sealing the space between the capsule and the inner surface of the hollow tubular element at a position downstream of at least one air intake.

[0257] Example 58. An aerosol generating article according to any one of Examples 1 to 51, wherein the inner surface of a hollow tubular element is corrugated at its upstream end to define a plurality of longitudinal channels arranged circumferentially so as to substantially coincide with at least one air intake.

[0258] Example 59. An aerosol generating article according to any one of Examples 1 to 58, wherein a hollow tubular element defines an empty cavity downstream of the capsule.

[0259] Example 60. The aerosol-generating article according to Example 59, wherein the empty cavity has a length of at least 10 millimeters.

[0260] Example 61. An aerosol generating article according to any one of Examples 1 to 60, wherein the hollow tubular element has a total length of at least 25 millimeters.

[0261] Example 62. An aerosol generating article according to any one of Examples 1 to 61, wherein the hollow tubular element has an inner diameter of at least 5 millimeters.

[0262] Example 63. An aerosol generating article according to any one of Examples 1 to 62, wherein the hollow tubular element has a wall thickness of at least about 100 micrometers.

[0263] Example 64. An aerosol-generating article according to any one of Examples 1 to 63, wherein the hollow tubular element contains a paper-based material.

[0264] Example 65. The aerosol generating article according to Example 64, wherein a hollow tubular element is formed from crimped paper.

[0265] Example 66. An aerosol-generating article according to any of Examples 1 to 65, wherein a hollow tubular element has an RTD of less than 10 mm of H2O.

[0266] Example 67. An aerosol generating article according to any one of Examples 1 to 66, further comprising a downstream filter segment mounted within a hollow tubular element at the downstream end of the hollow tubular element.

[0267] Example 68. The aerosol generating article according to Example 67, wherein the downstream filter segment is positioned at least 5 millimeters downstream from the downstream end of the capsule.

[0268] Example 69. The aerosol generating article according to Example 67 or 68, wherein the downstream filter segment has an RTD of less than 12 millimeters of H2O.

[0269] Example 70. An aerosol generating system comprising an aerosol generating article according to any one of Examples 1 to 69, a heating chamber for receiving the aerosol generating article, and a heating element provided inside or around the heating chamber.

[0270] Hereinafter, the present invention will be further described while referring to the drawings of the accompanying drawings.

[0271] The aerosol generating article 10 shown in FIG. 1 includes a hollow tubular element 12 and a capsule 14 attached to the upstream end of the hollow tubular element 12. The aerosol generating article 10 extends from an upstream or distal end 16 that substantially coincides with the upstream end of the hollow tubular element 12 to a downstream or mouth-side end 18 that coincides with the downstream end of the hollow tubular element 12.

[0272] The aerosol generating article 10 has an overall length of about 45 millimeters and an outer diameter of about 7.2 mm.

[0273] The hollow tubular element 12 is formed of a cylindrical cardboard tube having a wall thickness of approximately 0.25 millimeters. The hollow tubular element 12 defines an internal channel that extends between the upstream and downstream ends of the aerosol generating article. The hollow tubular element 12 has a length of about 45 millimeters, an outer diameter of about 7.2 millimeters, and an inner diameter of about 6.7 millimeters.

[0274] The capsule 14 is mounted at its upstream end within the internal channel of the hollow tubular element 12 such that the upstream end of the capsule 14 substantially coincides with the upstream end of the hollow tubular element 12.

[0275] Figure 4 shows a more detailed diagram of a suitable capsule 14 for use with the aerosol generating article 10.

[0276] Capsule 14 is a two-part capsule formed from an impermeable polymer such as HPMC. Capsule 14 has an elongated capsule (spherical cylindrical) shape with a round cross-section. The capsule includes a capsule outer wall 20 that defines an internal cavity 22 containing a plurality of beads 24 (not shown in Figure 1) of a solid aerosol generating substrate. The capsule outer wall 20 is defined by a cylindrical wall 26 and opposing hemispherical end walls 28 formed integrally with the cylindrical wall 26. Capsule 14 has a length of approximately 20 millimeters and an outer diameter of approximately 6.7 millimeters. Thus, the outer diameter of capsule 14 is similar to the inner diameter of the hollow tubular element 12, and as a result, the capsule is held within the hollow tubular element 12 by friction fitting.

[0277] The capsule has an internal volume of approximately 600 cubic millimeters and contains approximately 200 milligrams of solid aerosol-generating substrate. Therefore, the capsule contains approximately 0.33 milligrams of aerosol-generating substrate per cubic millimeter of internal cavity 22.

[0278] The capsule 14 includes a plurality of air intake ports 30, each of which is in the form of a hole penetrating the outer wall 20 of the capsule and has a diameter of approximately 0.5 millimeters. The plurality of air intake ports 30 are on the cylindrical wall 26 of the capsule 14, with gaps between them in a circumferential direction around the capsule. Each of the air intake ports 30 is provided approximately 8 millimeters downstream from the upstream end of the capsule.

[0279] The capsule 14 further includes a plurality of air outlets 32, each of which penetrates the outer wall 20 of the capsule and is in the form of a hole having a diameter of approximately 0.3 millimeters. The plurality of air outlets 32 are arranged in a circular pattern with gaps between them on the downstream end wall 28 of the capsule 14.

[0280] The hollow tubular element 12 is provided with a plurality of ventilation holes 34 that penetrate the peripheral wall of the hollow tubular element 12. Each of the ventilation holes 34 coincides with the air intake 30 of the capsule 14.

[0281] The arrangement of the air intake 30, air outlet 32, and vent 34 defines multiple airflow paths through the internal cavity 22 of the capsule 14, so that ambient air is drawn into the hollow tubular element 12 through the vent 34 during heating, and then through the capsule 14 to come into contact with the beads 24 of the solid aerosol generating substrate. The aerosol generated from the beads 24 of the solid aerosol generating substrate during heating is drawn out of the capsule 14 along the hollow tubular element 12 through the air outlet 32, together with the ambient air, to the downstream end of the aerosol generating article.

[0282] Each of the solid aerosol-generating bead 24 contained within the capsule 14 is spherical in shape with a diameter of 0.8 millimeters. The beads are formed from a gel composition having the following composition: [Table 1]

[0283] The aerosol generating article 100 shown in Figure 2 has a similar structure to the aerosol generating article 10 described above with respect to Figure 1, but has the following differences.

[0284] The hollow tubular element 112 of the aerosol generating article 100 has a similar structure to the hollow tubular element 12 of the aerosol generating article, but the hollow tubular element 112 does not have ventilation holes in its peripheral wall. Furthermore, the hollow tubular element 112 includes an annular flange 113 that extends inward from the inner surface of the hollow tubular element 112 at a distance of approximately 12 millimeters from the upstream end of the hollow tubular element 112. The annular flange 113 extends to the outer surface of the capsule 114 and functions to hold the capsule 114 in place within the hollow tubular element 112.

[0285] Capsule 114 is structurally similar to capsule 14 of aerosol generating article 10 shown in Figure 1, and includes similar arrangements of air intake 30 and air outlet 32. However, the outer diameter of capsule 114 is approximately 0.8 millimeters smaller than the inner diameter of the hollow tubular element 112 so that a space is provided between the outer surface of capsule 114 and the inner surface of the hollow tubular element 112. This space provides separation between capsule 114 and the hollow tubular element 112 and allows the air intake 30 on the cylindrical wall 26 to be exposed so that air can enter capsule 114 during use. The annular flange 113 holds capsule 114 in place and also maintains separation between capsule 114 and the inner surface of the hollow tubular element 112.

[0286] Capsule 114 contains multiple flakes of an aerosol-generating film (not shown) having the following composition: [Table 2]

[0287] The aerosol generating article 200 shown in Figure 3 includes a hollow tubular element 212, a capsule 214 attached to the upstream end of the hollow tubular element 112, and a downstream filter segment 250 attached to the downstream end of the hollow tubular element.

[0288] The hollow tubular element 212 of the aerosol generating article 200 has a structure similar to the hollow tubular element 12 of the aerosol generating article, but the hollow tubular element 212 does not have ventilation holes in its peripheral wall.

[0289] The capsule 214 is mounted within the hollow tubular element 212 such that approximately 50 percent of the capsule 214 extends beyond the upstream end of the hollow tubular element 212. Thus, the capsule 214 projects from the upstream end of the hollow tubular element 212, and the upstream end of the capsule 214 defines the upstream end of the aerosol generating article 200.

[0290] The capsule 214 has a size and shape similar to the capsule 14 described above in connection with FIGS. 1 and 4 and is held within the hollow tubular element 212 by a friction fit.

[0291] The capsule 214 includes a plurality of air inlets 230, each of which is in the form of a hole passing through the capsule outer wall 20 and has a diameter of about 0.5 millimeters. The plurality of air outlets 32 are circularly spaced on the upstream end wall of the capsule 214. The projection of the capsule 214 from the upstream end of the hollow tubular element 212 means that the air inlets 230 are located outside the hollow tubular element 212.

[0292] The capsule 214 also includes a plurality of air outlets 232, each of which is in the form of a hole extending through the capsule outer wall 20 and has a diameter of about 0.5 millimeters. The plurality of air outlets 32 are circularly spaced on the downstream end wall of the capsule 214. The air inlets 230 and the air outlets 232 are arranged to be substantially symmetric with each other at opposite ends of the capsule 214.

[0293] The capsule 214 contains a plurality of gel beads (not shown) having the same composition as those described above in connection with the embodiment shown in FIG. 1.

[0294] The downstream filter segment 250 extends from the capsule 214 through a gap and defines an empty cavity 252 inside the hollow tubular element 212. The empty cavity 252 has a length of approximately 25 millimeters. The downstream filter segment 250 extends to the downstream end of the hollow tubular element 212, and as a result, the downstream end of the downstream section 250 substantially coincides with the downstream end of the aerosol generating article 200.

[0295] The downstream filter segment 250 has a length of approximately 10 mm and contains a low-density cellulose acetate filter segment. The RTD of the downstream filter segment is approximately 10 mm H2O.

[0296] For the purposes of this specification and the appended claims, unless otherwise indicated, all numbers representing amounts, quantities, percentages, etc., are understood to be modified in all cases by the term “approximately.” Furthermore, all ranges include the disclosed maximum and minimum points and any intermediate ranges within them, which may or may not be specifically listed herein. Thus, in this context, the number A is understood as A ± 10%. In this context, the number A may be considered to include a number that falls within the general standard error of the measurement of the characteristic that the number A modifies. In some cases used in the appended claims, the number A may deviate by the percentages listed above, provided that the amount A deviates does not substantially affect the fundamental and novel characteristics of the claimed invention. Furthermore, all ranges include the disclosed maximum and minimum points and any intermediate ranges within them, which may or may not be specifically listed herein.

Claims

1. An aerosol generating article for generating an inhalable aerosol when heated, wherein the aerosol generating article is A hollow tubular element, A capsule attached to the hollow tubular element at the upstream end of the hollow tubular element, wherein the capsule is A capsule outer wall defining an internal cavity having a volume of at least 250 cubic millimeters, and A capsule comprising a solid aerosol generating substrate within the internal cavity of the capsule, comprising nicotine and an aerosol forming agent, wherein the aerosol forming agent content of the aerosol generating substrate is at least 15% by weight on a dry weight basis, and the density of the solid aerosol generating substrate within the capsule is at least 0.1 milligrams per cubic millimeter of the internal cavity, An aerosol generating article in which the hollow tubular element defines an empty cavity downstream of the capsule.

2. The aerosol generating article according to claim 1, wherein the empty cavity defined within the hollow tubular element has a length of at least 10 millimeters.

3. The aerosol generating article according to claim 1 or 2, wherein the empty cavity is defined within a hollow tubular element extending to the downstream end of the aerosol generating article.

4. The aerosol generating article according to claim 1 or 2, further comprising a downstream filter segment mounted within the hollow tubular element at the downstream end of the hollow tubular element.

5. The aerosol generating article according to any one of claims 1 to 4, wherein the outer wall of the capsule is formed of an impermeable polymer material.

6. The aerosol generating article according to any one of claims 1 to 5, wherein the capsule further includes at least one air intake and at least one air outlet in the outer wall of the capsule, and the at least one air intake and at least one air outlet define one or more airflow paths through the internal cavity.

7. The aerosol generating article according to claim 6, wherein at least one air intake port of the outer wall of the capsule is provided at least 2 millimeters downstream from the upstream end of the capsule.

8. The aerosol generating article according to claim 6 or 7, wherein at least one air intake is provided on the cylindrical wall of the capsule.

9. The aerosol generating article according to any one of claims 6 to 8, wherein the capsule protrudes from the upstream end of the hollow tubular element, so that at least one air intake is located outside the hollow tubular element.

10. The aerosol generating article according to any one of claims 1 to 9, wherein the solid aerosol generating substrate fills at least 50 percent of the volume of the internal cavity.

11. The aerosol generating article according to any one of claims 1 to 10, wherein the solid aerosol generating substrate comprises an aerosol generating film, the aerosol generating film comprises a cellulose-based film-forming agent, nicotine, and glycerol, and the aerosol generating film has a glycerol content of at least 40% by weight.

12. The aerosol generating article according to claim 11, wherein the aerosol generating film is substantially free of tobacco.

13. The aerosol generating article according to any one of claims 1 to 12, wherein the capsule comprises a plurality of particles of the solid aerosol generating substrate.

14. The aerosol generating article according to any one of claims 1 to 12, wherein the capsule contains one or more sheets of the solid aerosol generating substrate.

15. The aerosol generating article according to any one of claims 1 to 14, wherein the outer diameter of the capsule is at least 0.5 millimeters smaller than the inner diameter of the hollow tubular element.

16. The aerosol generating article according to any one of claims 1 to 15, wherein the inner wall of the hollow tubular element includes a plurality of longitudinally axially oriented waveforms.

17. Aerosol generation system, an aerosol generating article according to any one of claims 1 to 16 and An aerosol generating system comprising a heating chamber for receiving the aerosol generating article, and an aerosol generating device including a heating element provided inside or near the heating chamber.

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