Aerosol-generating article with downstream section

Abstract

An aerosol-generating article (10) for producing an inhalable aerosol upon heating, the aerosol-generating article (10) comprising: a rod of aerosol-generating substrate (12); a susceptor (60) arranged within the rod of aerosol-generating substrate (12); an upstream element (42) located upstream of the rod of aerosol-generating substrate (12) and abutting the upstream end of the rod of aerosol-generating substrate (12); and a downstream section (14) arranged downstream of the rod of aerosol-generating substrate (12), the downstream section (14) comprising: a hollow tubular element (20) abutting the downstream end of the rod of aerosol-generating substrate (12); and a mouthpiece element (50) located downstream of the hollow tubular element (30) and abutting the downstream end of the hollow tubular element (30), wherein a ratio of the length of the mouthpiece element (50) to the length of the hollow tubular element (20) is at least 0.5.

Description

[0001] P / 91280.W001

[0002] - 1 - AEROSOL-GENERATING ARTICLE WITH DOWNSTREAM SECTION

[0003] The present disclosure relates to an aerosol-generating article for generating an inhalable aerosol upon heating. The present disclosure also relates to an aerosol-generating system comprising an aerosol-generating article and an aerosol-generating device.

[0004] Aerosol-generating articles in which an aerosol-generating substrate, such as a tobaccocontaining substrate, is heated rather than combusted, are known in the art. Typically, in such heated smoking articles an aerosol is generated by the transfer of heat from a heat source to a physically separate aerosol-generating substrate or material, which may be located in contact with, within, around, or downstream of the heat source. During use of the aerosol-generating article, volatile compounds are released from the aerosol-generating substrate by heat transfer from the heat source and are entrained in air drawn through the aerosol-generating article. As the released compounds cool, they condense to form an aerosol.

[0005] A number of prior art documents disclose aerosol-generating devices for consuming aerosol-generating articles. Such devices include, for example, electrically heated aerosolgenerating devices in which an aerosol is generated by the transfer of heat from one or more electrical heater elements of the aerosol-generating device to the aerosol-generating substrate of a heated aerosol-generating article. For example, electrically heated aerosol-generating devices have been proposed that comprise an internal heater blade which is adapted to be inserted into the aerosol-generating substrate. As an alternative, inductively heatable aerosol-generating articles comprising an aerosol-generating substrate and a susceptor element arranged within the aerosol-generating substrate have been described in WO 2015 / 176898 A1.

[0006] Aerosol-generating articles in which a tobacco-containing substrate is heated rather than combusted present a number of challenges that were not encountered with conventional smoking articles.

[0007] First of all, tobacco-containing substrates are typically heated to significantly lower temperatures compared with the temperatures reached by the combustion front in a conventional cigarette. This may have an impact on nicotine release from the tobacco-containing substrate and nicotine delivery to the consumer. At the same time, if the heating temperature is increased in an attempt to boost nicotine delivery, then the generated aerosol typically needs to be cooled to a greater extent and more rapidly before it reaches the consumer. However, technical solutions that were commonly used for cooling the mainstream smoke in conventional smoking articles, such as the provision of a high filtration efficiency segment at the mouth end of a cigarette, may have undesirable effects in an aerosol-generating article wherein a tobacco-containing substrate is heated rather than combusted, as they may reduce nicotine delivery.

[0008] Secondly, a need is generally felt for aerosol-generating articles that are easy to use and have improved practicality. Further, it would be desirable to provide one such aerosol-generating article that can be manufactured efficiently and at high speed, preferably with low variability in terms of aerosol delivery and resistance to draw (RTD) from one article to another.

[0009] Therefore, it would be desirable to provide a new and improved aerosol-generating article adapted to achieve at least one of the desirable results described above. Further, it would be desirable to provide one such aerosol-generating article that can be manufactured efficiently and at high speed.

[0010] The present disclosure relates to an aerosol-generating article for producing an inhalable aerosol upon heating, the aerosol-generating article comprising a rod of aerosol-generating substrate. The aerosol-generating article may comprise an upstream element located upstream of the rod of aerosol-generating substrate. The upstream element may abut the upstream end of the rod of aerosol-generating substrate. The aerosol-generating article may comprise a downstream section arranged downstream of the rod of aerosol-generating substrate. The downstream section may comprise a hollow tubular element. The hollow tubular element may abut the downstream end of the rod of aerosol-generating substrate. The hollow tubular element may comprise a mouthpiece element. The mouthpiece element may be located downstream of the hollow tubular element. The mouthpiece element may abut the downstream end of the hollow tubular element. The aerosol-generating article may comprise a susceptor. The susceptor may be arranged within the rod of aerosol-generating substrate. A ratio of the length of the mouthpiece element to the length of the hollow tubular element may be at least 0.5.

[0011] In an example, the aerosol-generating article comprises: a rod of aerosol-generating substrate; an upstream element located upstream of the rod of aerosol-generating substrate and abutting the upstream end of the rod of aerosol-generating substrate; and a downstream section arranged downstream of the rod of aerosol-generating substrate, the downstream section comprising: a hollow tubular element abutting the downstream end of the rod of aerosolgenerating substrate; and a mouthpiece element located downstream of the hollow tubular element and abutting the downstream end of the hollow tubular element. The aerosol-generating article may comprise a susceptor. The susceptor may be arranged within the rod of aerosolgenerating substrate. A ratio of the length of the mouthpiece element to the length of the hollow tubular element may be at least 0.5.

[0012] The present disclosure also relates to an aerosol-generating system comprising an aerosol-generating article as described above and an aerosol-generating device, wherein the aerosol-generating device comprises a heating arrangement configured to heat at least a portion of the aerosol-generating substrate to generate an aerosol.

[0013] According to the present invention, there is provided an aerosol-generating article for producing an inhalable aerosol upon heating, the aerosol-generating article comprising: a rod of aerosol-generating substrate; a susceptor arranged within the rod of aerosol-generating substrate; an upstream element located upstream of the rod of aerosol-generating substrate and abutting the upstream end of the rod of aerosol-generating substrate; and a downstream section arranged downstream of the rod of aerosol-generating substrate, the downstream section comprising: a hollow tubular element abutting the downstream end of the rod of aerosolgenerating substrate; and a mouthpiece element located downstream of the hollow tubular element and abutting the downstream end of the hollow tubular element, wherein a ratio of the length of the mouthpiece element to the length of the hollow tubular element is at least 0.5.

[0014] Further, according to the present invention, there is provided an aerosol-generating system comprising an aerosol-generating article as described above and an aerosol-generating device, wherein the aerosol-generating device comprises a heating arrangement configured to heat at least a portion of the aerosol-generating substrate to generate an aerosol.

[0015] The aerosol-generating article according to the present invention provides an improved configuration of the elements of the aerosol-generating article for improved aerosol delivery to a user.

[0016] The downstream section of the aerosol-generating article comprising a hollow tubular element and a mouthpiece element, wherein a ratio of the length of the mouthpiece element to the length of the hollow tubular element is at least 0.5 provides a desired balance between the size of the internal cavity of the hollow tubular element, the structural rigidity of the hollow tubular element, the filtration level and resistance to draw of the downstream section and the structural rigidity of the downstream section. The downstream section of the aerosol-generating article thus advantageously provides a balance between desired nucleation of aerosol particles generated by the rod of aerosol-generating substrate, cooling of the aerosol for delivery to a user, filtration level and resistance to draw of the aerosol-generating article, resistance to deformation and ease of handling of the aerosol-generating article and in particular resistance to deformation and ease of handling of the aerosol-generating article during insertion and removal of the aerosol-generating article from an aerosol-generating device.

[0017] The downstream section of the aerosol-generating article as described herein abutting the downstream end of the rod of aerosol-generating substrate and the upstream end of the mouthpiece element may reduce the number of elements in the downstream section. This may advantageously reduce variability in the downstream section of one aerosol-generating article to another and thus reduce the variability in aerosol delivery and the resistance to draw from one aerosol-generating article to another.

[0018] The term “aerosol-generating article” is used herein to denote an article wherein an aerosol-generating substrate is heated to produce and deliver inhalable aerosol to a consumer. As used herein, the term “aerosol-generating substrate” denotes a substrate capable of releasing volatile compounds upon heating to generate an aerosol. A conventional cigarette is lit when a user applies a flame to one end of the cigarette and draws air through the other end. The localised heat provided by the flame and the oxygen in the air drawn through the cigarette causes the end of the cigarette to ignite, and the resulting combustion generates an inhalable smoke. By contrast, in heated aerosol generating articles, an aerosol is generated by heating a flavour generating substrate, such as tobacco. Known heated aerosol generating articles include, for example, electrically heated aerosol-generating articles and aerosol-generating articles in which an aerosol is generated by the transfer of heat from a combustible fuel element or heat source to a physically separate aerosol forming material.

[0019] As used herein, the term “aerosol-generating device” refers to a device comprising a heater element that interacts with the aerosol-generating substrate of the aerosol generating article to generate an aerosol. For example, aerosol-generating devices are known wherein heating of the aerosol-generating substrate is achieved inductively by means of a susceptor provided within the aerosol-generating substrate.

[0020] Upon heating, volatile compounds are released from the aerosol-generating substrate and entrained in air drawn through the aerosol-generating article. As the released compounds cool, they condense to form an aerosol that is inhaled by the consumer. The aerosol generated upon heating the aerosol-generating substrate is a dispersion of solid particles or liquid droplets (or a combination of solid particles and liquid droplets) in a gas. The aerosol may be visible or invisible and may include vapours of substances that are ordinarily liquid or solid at room temperature as well as solid particles or liquid droplets or a combination of solid particles and liquid droplets.

[0021] As used herein with reference to the present disclosure, the term “rod” is used to denote a generally cylindrical element of substantially circular, oval or elliptical cross-section.

[0022] As used herein, the term “longitudinal” refers to the direction corresponding to the main longitudinal axis of the aerosol-generating article, which extends between the upstream and downstream ends of the aerosol-generating article.

[0023] As used herein, the terms ‘“distal”, “upstream” “proximal” and “downstream” describe the relative positions of components, or portions of components, of an aerosol-generating article or aerosol generating device. Aerosol generating articles and devices according to the present disclosure have a proximal end through which, in use, an aerosol exits the article or device for delivery to a user, and have an opposing distal end. The proximal end of the aerosol generating article and device may also be referred to as the mouth end. In use, a user draws on the proximal end of the aerosol-generating article in order to inhale the aerosol generated by the aerosol generating article or device. The terms upstream and downstream are relative to the direction of aerosol movement through the aerosol-generating article or aerosol-generating device when a user draws on the proximal end of the aerosol-generating article. The proximal end of the aerosolgenerating article is downstream of the distal end of the aerosol-generating article. The proximal end of the aerosol-generating article may also be referred to as the downstream end of the aerosol-generating article and the distal end of the aerosol-generating article may also be referred to as the upstream end of the aerosol-generating article.

[0024] During use, air is drawn through the aerosol-generating article in the longitudinal direction. The term “transverse” refers to the direction that is perpendicular to the longitudinal axis. Any reference to the “cross-section” of the aerosol-generating article or a component of the aerosolgenerating article refers to the transverse cross-section unless stated otherwise.

[0025] The term “length” denotes the maximum dimension of the aerosol-generating article or of a component of the aerosol-generating article in the longitudinal direction.

[0026] As used herein with reference to the invention, the term “transverse” is used to describe the direction perpendicular to the longitudinal direction. Unless otherwise stated, references to the “cross-section” of the aerosol-generating article or aerosol-generating device or a component of the aerosol-generating article or aerosol-generating device refer to the transverse crosssection. As used herein with reference to the invention, the term “width” denotes the maximum dimension of the aerosol-generating article or device or of a component of the aerosol-generating article or device in a transverse direction. For example, where the aerosol-generating article has a substantially circular cross-section, the width of the aerosol-generating article corresponds to the diameter of the aerosol-generating article. Where a component of the aerosol-generating article has a substantially circular cross-section, the width of the component of the aerosolgenerating article substantially corresponds to the diameter of the component of the aerosolgenerating article.

[0027] The hollow tubular element may comprise a paper-based material. The hollow tubular element may be formed from a paper-based material.

[0028] The hollow tubular element may comprise paper. The hollow tubular element may comprise 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 parchment paper.

[0029] Preferably, the hollow tubular element comprises cardboard. The hollow tubular element may be 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 in order to provide ease of insertion of the article into an aerosol-generating device and being sufficiently stiff to provide suitable engagement of the article with the interior of the device. A cardboard tube may therefore provide suitable resistance to deformation or compression during use.

[0030] The hollow tubular element may be a tube formed from spirally wound paper. The hollow tubular element may be formed from a plurality of 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. For example, the hollow tubular element may be a cardboard tube formed from spirally wound paper.

[0031] Preferably, a content of cellulose acetate in the hollow tubular element is less than or equal to 15 percent by weight. Preferably, a content of cellulose acetate in the hollow tubular element is less than or equal to 10 percent by weight. More preferably, a content of cellulose acetate in the hollow tubular element is less than or equal to 5 percent by weight. Even more preferably, the hollow tubular element is substantially free of cellulose acetate. This may improve the biodegradability of the hollow tubular element.

[0032] The hollow tubular element may comprise a polymeric material. For example, the hollow tubular element may comprise a polymeric film. The polymeric film may comprise a cellulosic film. The hollow tubular element may comprise low density polyethylene (LDPE) or polyhydroxyalkanoate (PHA) fibres. The hollow tubular element may comprise cellulose acetate tow.

[0033] The hollow tubular element defines an internal cavity. Preferably, the cavity is empty. The thickness of a peripheral wall (in other words, the wall thickness) of the hollow tubular element may be at least about 100 micrometres. The wall thickness of the hollow tubular element may be at least about 150 micrometres. The wall thickness of the hollow tubular element may be at least about 200 micrometres.

[0034] The wall thickness of the hollow tubular element may be less than or equal to about 1 millimetre. The wall thickness of the hollow tubular element may be less than or equal to about 500 micrometres. The wall thickness of the hollow tubular element may be less than or equal to 300 micrometres. The wall thickness of the hollow tubular element may be less than or equal to 275 micrometres. The wall thickness of the hollow tubular element may be less than or equal to 250 micrometres.

[0035] The wall thickness of the hollow tubular element discussed above provides a desired balance between maximising the volume of the internal cavity of the hollow tubular element and the structural rigidity of the hollow tubular element and of the downstream section of the aerosolgenerating article.

[0036] Keeping the thickness of the peripheral wall of the hollow tubular element relatively low ensures that the overall internal volume of the hollow tubular element - which is made available for the aerosol to begin the nucleation process as soon as the aerosol components leave the rod of aerosol-generating substrate - and the cross-sectional surface area of the hollow tubular element are effectively maximised, whilst at the same time ensuring that the hollow tubular element has the necessary structural strength to prevent a collapse of the aerosol-generating article as well as to provide some support to the rod of aerosol-generating substrate, and that the RTD of the hollow tubular element is minimised. Greater values of cross-sectional surface area of the cavity of the hollow tubular element are understood to be associated with a reduced speed of the aerosol stream travelling along the aerosol-generating article, which is also expected to favour aerosol nucleation. Further, it would appear that by utilising a hollow tubular element having a relatively low thickness, it is possible to substantially prevent diffusion of the ventilation air prior to its contacting and mixing with the stream of aerosol, which is also understood to further favour nucleation phenomena. In practice, by providing a more controllably localised cooling of the stream of volatilised species, it is possible to enhance the effect of cooling on the formation of new aerosol particles.

[0037] The hollow tubular element may have a wall thickness of between about 100 micrometres, and about 1 millimetre, between about 100 micrometres and about 500 micrometres, or between about 100 micrometres and about 300 micrometres. Preferably, the hollow tubular element has a wall thickness between about 100 micrometres and about 275 micrometres, and more preferably between about 100 micrometres and 250 micrometres.

[0038] The hollow tubular element may have a wall thickness of between about 150 micrometres, and about 1 millimetre, between about 150 micrometres and about 500 micrometres, or between about 150 micrometres and about 300 micrometres. Preferably, the hollow tubular element has a wall thickness between about 150 micrometres and about 275 micrometres, and more preferably between about 150 micrometres and 250 micrometres.

[0039] The hollow tubular element may have a wall thickness of between about 200 micrometres, and about 1 millimetre, between about 200 micrometres and about 500 micrometres, or between about 200 micrometres and about 300 micrometres. Preferably, the hollow tubular element has a wall thickness between about 200 micrometres and about 275 micrometres, and more preferably between about 200 micrometres and 250 micrometres.

[0040] The wall thickness of the hollow tubular element described herein may refer to the wall thickness of the hollow tubular element that is substantially constant around a majority of the hollow tubular element. In other words, a majority (at least 50%) of the hollow tubular element may have a substantially constant wall thickness, and the wall thickness of the hollow tubular element described herein may refer to the wall thickness of the hollow tubular element at locations along and around the hollow tubular element having this substantially constant wall thickness.

[0041] The wall thickness of the hollow tubular element may be substantially constant around at least 75 percent of the circumference of the hollow tubular element, at least 80 percent of the circumference of the hollow tubular element, or at least 85% of the circumference of the hollow tubular element.

[0042] The wall thickness of the hollow tubular element described herein may refer to the thickness of the hollow tubular element that is substantially constant around at least 75 percent of the circumference of the hollow tubular element, at least 80 percent of the circumference of the hollow tubular element, or at least 85% of the circumference of the hollow tubular element. The hollow tubular element may comprise a uniform thickness section having a substantially constant wall thickness, the uniform thickness section may extend around at least 75 percent of the circumference of the hollow tubular element, or at least 80 percent of the circumference of the hollow tubular element, or at least 85 percent of the circumference of the hollow tubular element. The uniform thickness section may be a uniform thickness longitudinal section. The uniform thickness section may extend from the upstream end of the hollow tubular element to the downstream end of the hollow tubular element.

[0043] The wall thickness of the hollow tubular element described herein may be measured at the uniform thickness section of the hollow tubular element.

[0044] The hollow tubular element may be formed from a sheet. The hollow tubular element may comprise a seam, the seam being formed from overlapped layers of the sheet.

[0045] The wall thickness of the hollow tubular element described herein may not be measured at a seam of the hollow tubular element.

[0046] Where the aerosol-generating article comprises a wrapper circumscribing at least a portion of the hollow tubular element and another element longitudinally aligned with the hollow tubular element, the wall thickness of the hollow tubular element does not take into account the thickness of this wrapper. This is because such wrapper is not a component of the hollow tubular element. Instead, this wrapper adjoins the hollow tubular element and the another element longitudinally aligned with the hollow tubular element.

[0047] For example, where the aerosol-generating article comprises tipping wrapper circumscribing at least a portion of the hollow tubular element and at least a portion of the mouthpiece element, the wall thickness of the hollow tubular element does not take into account the thickness of the tipping wrapper. The tipping wrapper is not a component of the hollow tubular element.

[0048] The hollow tubular element may consist of a single hollow tubular segment. The hollow tubular element may consist of a single continuous hollow tubular segment.

[0049] Preferably, the hollow tubular element has a substantially constant internal diameter along the entire length of the hollow tubular element. However, the internal diameter of the hollow tubular element may vary along the length of the hollow tubular element.

[0050] The hollow tubular element may have an internal diameter of at least about 4 millimetres, at least about 5 millimetres, at least about 6 millimetres, or at least about 6.5 millimetres.

[0051] The provision of a hollow tubular element having an internal diameter as set out above may advantageously reduce the resistance to draw of the hollow tubular element.

[0052] The hollow tubular element may have an internal diameter of no more than about 10 millimetres. For example, the hollow tubular element may have an internal diameter of no more than about 9 millimetres, no more than about 8 millimetres, or no more than about 7.5 millimetres, or no more than 7 millimetres. The provision of a hollow tubular element having an internal diameter as set out above may advantageously provide sufficient rigidity and strength to the hollow tubular element.

[0053] The hollow tubular element may have an internal diameter of between about 2 millimetres and about 10 millimetres, between about 4 millimetres and about 9 millimetres, between about 5 millimetres and about 8 millimetres, between about 6 millimetres and about 7.5 millimetres, or between about 6.5 millimetres and about 7 millimetres. .

[0054] A ratio between the wall thickness of the hollow tubular element to the internal diameter of the hollow tubular element may be at least 0.01, preferably at least 0.02, more preferably at least 0.03.

[0055] A ratio between the wall thickness of the hollow tubular element to the internal diameter of the hollow tubular element may be less than or equal to 0.1 , preferably less than or equal to 0.08, less than or equal to 0.06, more preferably less than or equal to 0.04.

[0056] A ratio between the wall thickness of the hollow tubular element to the internal diameter of the hollow tubular element may be between 0.01 and 0.1, between 0.01 and 0.08, between 0.01 and 0.06, or between 0.01 and 0.04. A ratio between the wall thickness of the hollow tubular element to the internal diameter of the hollow tubular element may be between 0.02 and 0.1, between 0.02 and 0.08, between 0.02 and 0.06, or between 0.02 and 0.04. A ratio between the wall thickness of the hollow tubular element to the internal diameter of the hollow tubular element may be between 0.03 and 0.1, between 0.03 and 0.08, between 0.03 and 0.06, or between 0.03 and 0.04.

[0057] The provision of a hollow tubular element having a small wall thickness relative to the internal diameter of the hollow tubular element may advantageously reduce the resistance to draw of the hollow tubular element and enhance cooling and nucleation of aerosol particles.

[0058] The ratio between an internal diameter of the hollow tubular element and the external diameter of the hollow tubular element may be at least about 0.8. For example, the ratio between an internal diameter of the hollow tubular element and the external diameter of the hollow tubular element may be at least about 0.85, or at least about 0.9.

[0059] The ratio between an internal diameter of the hollow tubular element and the external diameter of the hollow tubular element may be no more than about 0.99. For example, the ratio between an internal diameter of the hollow tubular element and the external diameter of the hollow tubular element may be no more than about 0.98.

[0060] The provision of a relatively large internal diameter may advantageously reduce the resistance to draw of the hollow tubular element and enhance cooling and nucleation of aerosol particles. 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. The hollow tubular element preferably has an external diameter that is approximately equal to the external diameter of the rod of aerosol-generating substrate and to the external diameter of the aerosol-generating article.

[0061] The hollow tubular element may have an external diameter of between 5 millimetres and 12 millimetres, for example of between 5 millimetres and 10 millimetres, of between 6 millimetres and 8 millimetres, or of between 7 millimetres and 8 millimetres. The hollow tubular element may have an external diameter of about 7.0 millimetres.

[0062] The length of the hollow tubular element may be at least about 12 millimetres, preferably at least 14 millimetres, more preferably at least 16 millimetres.

[0063] The length of the hollow tubular element may be less or equal than about 22 millimetres, preferably less than or equal to 20 millimetres, more preferably less than or equal to 18 millimetres.

[0064] The length of the hollow tubular element may be between 12 millimetres and 22 millimetres, between 12 millimetres and 20 millimetres, or between 12 millimetres and 18 millimetres. The length of the hollow tubular element may be between 14 millimetres and 22 millimetres, between 14 millimetres and 20 millimetres, or between 14 millimetres and 18 millimetres. The length of the hollow tubular element may be between 16 millimetres and 22 millimetres, between 16 millimetres and 20 millimetres, or between 16 millimetres and 18 millimetres.

[0065] Preferably, the length of the hollow tubular element is about 17 mm.

[0066] A relatively long hollow tubular element provides and defines a relatively long internal cavity within the aerosol-generating article and downstream of the rod of aerosol-generating substrate. As discussed in the present disclosure, providing an empty cavity downstream (preferably, immediately downstream) of the aerosol-generating substrate enhances the nucleation of aerosol particles generated by the substrate. Providing a relatively long cavity maximises such nucleation benefits, thereby improving aerosol formation and cooling.

[0067] The desired length of the hollow tubular element is based on a balance between maximising nucleation benefits and the structural strength of the hollow tubular element and thus the structural strength of the downstream section of the aerosol-generating article. Increasing the strength of the hollow tubular element may provide an aerosol-generating article that is resistant to deformation during handling by a user, such as during insertion and removal of the aerosolgenerating article from an aerosol-generating device.

[0068] A ratio of the length of the rod of aerosol-generating substrate to the length of the hollow tubular element may be less than or equal to about 1 , preferably less than or equal to about 0.85, more preferably less than or equal to about 0.7. A ratio of the length of the rod of aerosol-generating substrate to the length of the hollow tubular element may be at least about 0.3, preferably at least about 0.45, more preferably at least about 0.6.

[0069] A ratio of the length of the rod of aerosol-generating substrate to the length of the hollow tubular element may be between 0.3 and 1, between 0.3 and 0.8, or between 0.3 and 0.7. A ratio of the length of the rod of aerosol-generating substrate to the length of the hollow tubular element may be between 0.45 and 1 , between 0.45 and 0.8, or between 0.45 and 0.7. A ratio of the length of the rod of aerosol-generating substrate to the length of the hollow tubular element may be between 0.6 and 1, between 0.6 and 0.8, or between 0.6 and 0.7.

[0070] The hollow tubular element is preferably longer than the rod of aerosol-generating substrate.

[0071] The ratios of the length of the rod of aerosol-generating substrate to the length of the hollow tubular element described herein are based on a desired balance between the amount of particles that are volatilised from the aerosol-generating substrate and nucleation of aerosol particles generated by the substrate and cooling of aerosol to provide a user with an improved sensory experience.

[0072] A ratio between a length of the hollow tubular element and an overall length of the aerosolgenerating article may be less than or equal to about 0.6. Preferably, a ratio between a length of the hollow tubular element and an overall length of the aerosol-generating article may be less than or equal to about 0.5. More preferably, a ratio between a length of the hollow tubular element and an overall length of the aerosol-generating article may be less than or equal to about 0.4.

[0073] A ratio between a length of the hollow tubular element and an overall length of the aerosolgenerating article may be at least about 0.2. Preferably, a ratio between a length of the hollow tubular element and an overall length of the aerosol-generating article may be at least about 0.25. More preferably, a ratio between a length of the hollow tubular element and an overall length of the aerosol-generating article may be at least about 0.3.

[0074] A ratio between the length of the hollow tubular element and the overall length of the aerosol-generating article may be between 0.2 and 0.6, between 0.2 and 0.5, or between 0.2 and 0.4. A ratio between the length of the hollow tubular element and the overall length of the aerosolgenerating article may be between 0.25 and 0.6, between 0.25 and 0.5, or between 0.25 and 0.4. A ratio between the length of the hollow tubular element and the overall length of the aerosolgenerating article may be between 0.3 and 0.6, between 0.3 and 0.5, or between 0.3 and 0.4.

[0075] Providing a hollow tubular element with the ratios listed above balances maximisation of the aerosol cooling and formation benefits of having a relatively long hollow tubular element and increasing the structural rigidity of the hollow tubular element and that of the aerosol-generating article by having a relatively short hollow tubular element. Further, providing a longer hollow tubular element may advantageously lower the effective RTD of the downstream section of the aerosol-generating article, which may primarily be defined by the RTD of a mouthpiece element.

[0076] The mouthpiece element may extend from a downstream end of the downstream section. The mouthpiece element may be located at the downstream end of the aerosol-generating article. The downstream end of the mouthpiece element may define the downstream end of the aerosolgenerating article. The mouthpiece element may extend between the hollow tubular element and the downstream end of the aerosol-generating article.

[0077] The mouthpiece element is preferably connected to one or more of the adjacent upstream components of the aerosol-generating article by means of a tipping wrapper. For example, the mouthpiece may be connected to the hollow tubular element by a tipping wrapper.

[0078] The mouthpiece element may comprise a mouthpiece filter segment formed of a fibrous filtration material.

[0079] The fibrous filtration material may be for filtering the aerosol that is generated from the aerosol-generating substrate. The mouthpiece element may comprise a cellulose acetate filter segment formed of cellulose acetate tow.

[0080] The mouthpiece element may comprise cellulose acetate (such as a solid plug of cellulose acetate), paper, viscose, or lyocell. Preferably, the mouthpiece element comprises paper, viscose, or lyocell. More preferably, the mouthpiece element comprises viscose or lyocell.

[0081] The mouthpiece element may be made of or formed from cellulose acetate, paper, viscose, or lyocell. Preferably, the mouthpiece element is made of or formed from paper, viscose or lyocell. More preferably, the mouthpiece element is made of or formed from viscose or lyocell.

[0082] A mouthpiece element made of or formed from paper, viscose, or lyocell may provide a balance between the desired level of filtration for the aerosol-generating article while allowing desired nicotine and aerosol former deliveries and the strength and rigidity of the mouthpiece element.

[0083] Preferably, a content of cellulose acetate in the mouthpiece element may be less than or equal to 15 percent by weight. Preferably, a content of cellulose acetate in the mouthpiece element is less than or equal to 10 percent by weight. More preferably, a content of cellulose acetate in the mouthpiece element may be less than or equal to 5 percent by weight. Even more preferably, the mouthpiece element is substantially free of cellulose acetate.

[0084] The aerosol-generating article may comprise a capsule located inside the mouthpiece element. The capsule may be a flavour capsule containing a flavourant. The capsule may be a breakable capsule. A user may apply force to the mouthpiece element which breaks the capsule to release a flavourant. The mouthpiece element having a length as described below may be particularly advantageous to accommodate a capsule.

[0085] The mouthpiece element preferably has an external diameter that is approximately equal to the external diameter of the aerosol-generating article. The mouthpiece element preferably has an external diameter that is approximately equal to the external diameter of the rod of aerosolgenerating substrate. The external diameter of the mouthpiece element may be substantially the same as the external diameter of the hollow tubular element.

[0086] The external diameter of the mouthpiece element may be between about 5 mm and about 12 millimetres. The external diameter of the mouthpiece element may be between about 5 mm and about 10 mm. The external diameter of the mouthpiece element may be between about 6 mm and about 8 mm. The external diameter of the mouthpiece element may be between about 7 mm and about 8 mm. The external diameter of the mouthpiece element may be about 7.2 mm. The external diameter of the mouthpiece element may be about 7.15 mm.

[0087] The length of the mouthpiece element may be at least about 6 millimetres, preferably at least about 8 millimetres, more preferably at least about 10 millimetres. .

[0088] The length of the mouthpiece element may equal to or less than about 18 millimetres, preferably equal to or less than 16 millimetres, more preferably equal to or less than 14 millimetres.

[0089] The length of the mouthpiece element may be between about 6 millimetres and about 18 millimetres, between about 6 millimetres and about 16 millimetres, or between about 6 millimetres and about 14 millimetres. The length of the mouthpiece element may be between about 8 millimetres and about 18 millimetres, between about 8 millimetres and about 16 millimetres, or between about 8 millimetres and about 14 millimetres. The length of the mouthpiece element may be between about 10 millimetres and about 18 millimetres, between about 10 millimetres and about 16 millimetres, or between about 10 millimetres and about 14 millimetres.

[0090] Preferably, the length of the mouthpiece element is about 12 millimetres.

[0091] The length of the mouthpiece element descried herein is based on a desired level of filtration of aerosol. Increasing the length of the mouthpiece element may increase the filtration level of the aerosol-generating article. This may particularly be the case where filtration is primarily effected by the mouthpiece element.

[0092] The length of the mouthpiece element described herein provides the downstream section of the aerosol-generating article with a desired rigidity. Where the mouthpiece element is harder or more rigid than the hollow tubular element, increasing the length of the mouthpiece element may increase the overall hardness or rigidity of the downstream section.

[0093] A ratio of the length of the mouthpiece element to the length of the hollow tubular element may be at least 0.5, preferably at least 0.6, more preferably at least 0.7.

[0094] A ratio of the length of the mouthpiece element to the length of the hollow tubular element may be less than or equal to 1.2, preferably less than or equal to 1 , more preferably less than or equal to 0.8.

[0095] A ratio of the length of the mouthpiece element to the length of the hollow tubular element may be between 0.5 and 1.2, between 0.5 and 1, or between 0.5 and 0.8. A ratio of the length of the mouthpiece element to the length of the hollow tubular element may be between 0.6 and 1.2, between 0.6 and 1 , or between 0.6 and 0.8. A ratio of the length of the mouthpiece element to the length of the hollow tubular element may be between 0.7 and 1.2, between 0.7 and 1 , or between 0.7 and 0.8.

[0096] Preferably, the length of the mouthpiece element is at least half the length of the hollow tubular element.

[0097] Preferably, the hollow tubular element is longer than the mouthpiece element.

[0098] The ratio of the length of the mouthpiece element to the length of the hollow tubular element described herein is based on a desired balance between the rigidity of the downstream section, the nucleation and formation of aerosol, and filtration of aerosol.

[0099] A ratio of the length of the mouthpiece element to the length of the rod of aerosolgenerating substrate may be at least 0.7, preferably at least 0.85, more preferably at least 1.

[0100] A ratio of the length of the mouthpiece element to the length of the rod of aerosolgenerating substrate may be less than or equal to 2, preferably less than or equal to 1.6, more preferably less than or equal to 1.2.

[0101] A ratio of the length of the mouthpiece element to the length of the rod of aerosolgenerating substrate may be between 0.7 and 2, between 0.7 and 1.6, or between 0.7 and 1.2. A ratio of the length of the mouthpiece element to the length of the rod of aerosol-generating substrate may be between 0.85 and 2, between 0.85 and 1.6, or between 0.85 and 1.2. A ratio of the length of the mouthpiece element to the length of the rod of aerosol-generating substrate may be between 1 and 2, between 1 and 1.6, or between 1 and 1.2.

[0102] Preferably, the mouthpiece element is longer than the rod of aerosol-generating substrate. The ratio of the length of the mouthpiece element to the length of the rod of aerosolgenerating substrate described herein is based on a desired balance between the amount of aerosol generated by the rod of aerosol-generating substrate and filtration of the aerosol.

[0103] A ratio of the length of the mouthpiece element to the length of the aerosol-generating article may be at least 0.18, preferably at least 0.2, more preferably at least 0.22, even more preferably at least 0.25.

[0104] A ratio of the length of the mouthpiece element to the length of the aerosol-generating article may be less than or equal to 0.4, preferably less than or equal to 0.35, more preferably less than or equal to 0.3.

[0105] A ratio of the length of the mouthpiece element to the length of the aerosol-generating article may be between 0.18 and 0.4, between 0.18 and 0.35, or between 0.18 and 0.3. A ratio of the length of the mouthpiece element to the length of the aerosol-generating article may be between 0.2 and 0.4, between 0.2 and 0.35, or between 0.2 and 0.3. A ratio of the length of the mouthpiece element to the length of the aerosol-generating article may be between 0.22 and 0.4, between 0.22 and 0.35, or between 0.22 and 0.3. A ratio of the length of the mouthpiece element to the length of the aerosol-generating article may be between 0.25 and 0.4, between 0.25 and 0.35, or between 0.25 and 0.3.

[0106] The downstream section may extend from the downstream end of the rod of aerosolgenerating substrate to the downstream end of the aerosol-generating article.

[0107] The downstream section may comprise the mouthpiece element and the hollow tubular element, wherein the hollow tubular element extends from the upstream end of the downstream section to the upstream end of the mouthpiece element, and the mouthpiece element extends from the downstream end of the hollow tubular element to the downstream end of the downstream section.

[0108] The overall length of the downstream section may correspond to the sum of the length of the hollow tubular element and the length of the mouthpiece element.

[0109] A content of cellulose acetate in the downstream section may be less than or equal to 15 percent by weight. Preferably, a content of cellulose acetate in the downstream section is less than or equal to 10 percent by weight. More preferably, a content of cellulose acetate in the downstream section is less than or equal to 5 percent by weight. Even more preferably, the downstream section is substantially free of cellulose acetate.

[0110] The aerosol-generating article may further comprise a ventilation zone at a location along the downstream section. Preferably, the aerosol-generating article comprises a ventilation zone at a location along the hollow tubular element. This enables ingress of air from an exterior of the aerosol-generating article into the internal cavity of the hollow tubular element when the consumer draws upon a mouth end of the aerosol-generating article, which is associated with a number of benefits.

[0111] Where the aerosol-generating article comprises a ventilation zone located along the hollow tubular element, the hollow tubular element having a length as described herein may advantageously have sufficient rigidity to resist deformation by a user, such as during handling or insertion or removal of the aerosol-generating article from an aerosol-generating device.

[0112] The ventilation zone may comprise a plurality of openings or perforations through a component of the aerosol-generating article, such as through the peripheral wall of the hollow tubular element when the ventilation zone is at a location along the hollow tubular element.

[0113] The ventilation zone may comprise at least one row of openings or perforations. The ventilation zone may comprise a single row of openings or perforations.

[0114] Preferably, the ventilation zone comprises at least one circumferential row of openings or perforations. The ventilation zone may comprise two circumferential rows of openings or perforations. For example, the openings or perforations may be formed online during manufacturing of the aerosol-generating article. Preferably, each circumferential row of openings or perforations comprises from 8 to 30 perforations, such as from 8 to 12 perforations. In an example, each circumferential row of openings or perforations comprises 9 perforations. The openings or perforations may be in the form of slits.

[0115] For example, the ventilation zone may comprise at least one row of slits. The ventilation zone may comprise a single row of slits. The ventilation zone may comprise a single row of between 8 to 30 slits, such as 8 to 12 slits. In an example, the ventilation zone comprises a single row of 9 slits.

[0116] The openings or perforations may each have a width or a length of at least 0.05 millimetres.

[0117] A distance between the ventilation zone and the downstream end of the aerosolgenerating article may be at least 12 millimetres, preferably at least 14 millimetres, more preferably at least 16 millimetres.

[0118] A distance between the ventilation zone and the downstream end of the aerosolgenerating article may be less than or equal to 24 millimetres, preferably less than or equal to 22 millimetres, more preferably less than or equal to 20 millimetres.

[0119] A distance between the ventilation zone and the downstream end of the aerosolgenerating article may be between 12 millimetres and 24 millimetres, between 12 millimetres and 22 millimetres, or between 12 millimetres and 20 millimetres. A distance between the ventilation zone and the downstream end of the aerosol-generating article may be between 14 millimetres and 24 millimetres, between 14 millimetres and 22 millimetres, or between 14 millimetres and 20 millimetres. A distance between the ventilation zone and the downstream end of the aerosolgenerating article may be between 16 millimetres and 24 millimetres, between 16 millimetres and 22 millimetres, or between 16 millimetres and 20 millimetres.

[0120] Preferably, a distance between the ventilation zone and the downstream end of the aerosol-generating article is 18 millimetres.

[0121] A distance between the ventilation zone and the upstream end of the hollow tubular element may be at least 6 millimetres, at least 8 millimetres, or at least 10 millimetres.

[0122] A distance between the ventilation zone and the upstream end of the hollow tubular element may be less than or equal to 16 millimetres, less than or equal to 14 millimetres, or less than or equal to 12 millimetres.

[0123] A distance between the ventilation zone and the upstream end of the hollow tubular element is between 6 millimetres and 16 millimetres, between 6 millimetres and 14 millimetres, or between 6 millimetres and 12 millimetres. A distance between the ventilation zone and the upstream end of the hollow tubular element is between 8 millimetres and 16 millimetres, between 8 millimetres and 14 millimetres, or between 8 millimetres and 12 millimetres. A distance between the ventilation zone and the upstream end of the hollow tubular element is between 10 millimetres and 16 millimetres, between 10 millimetres and 14 millimetres, or between 10 millimetres and 12 millimetres. Preferably, a distance between the ventilation zone and the upstream end of the hollow tubular element is about 11 millimetres.

[0124] A distance between the ventilation zone and the upstream end of the hollow tubular element discussed herein is based on a desired level of cooling of aerosol through the hollow tubular element upstream of the ventilation zone and cooling of aerosol through admission of cooler air into the hollow tubular element at the ventilation zone.

[0125] A distance between the ventilation zone and the downstream end of the hollow tubular element may be at least 2 millimetres, at least 4 millimetres, or at least 6 millimetres.

[0126] A distance between the ventilation zone and the downstream end of the hollow tubular element may be less than or equal to 12 millimetres, less than or equal to 10 millimetres, or less than or equal to 8 millimetres.

[0127] A distance between the ventilation zone and the downstream end of the hollow tubular element may be between 2 millimetres and 12 millimetres, between 2 millimetres and 10 millimetres, or between 2 millimetres and 8 millimetres. A distance between the ventilation zone and the downstream end of the hollow tubular element may be between 4 millimetres and 12 millimetres, between 4 millimetres and 10 millimetres, or between 4 millimetres and 8 millimetres. A distance between the ventilation zone and the downstream end of the hollow tubular element may be between 6 millimetres and 12 millimetres, between 6 millimetres and 10 millimetres, or between 6 millimetres and 8 millimetres.

[0128] Preferably, a distance between the ventilation zone and the downstream end of the hollow tubular element is about 6 millimetres.

[0129] The distance between the ventilation zone and the downstream end of the hollow tubular element discussed herein is based on a desired level of mixing of aerosol generated by the aerosol-generating substrate and air admitted into the aerosol-generating article through the ventilation zone prior to delivery to a user.

[0130] An aerosol-generating article in accordance with the present disclosure may have a ventilation level of at least about 5 percent.

[0131] The term “ventilation level” is used throughout the present specification to denote a volume ratio between of the airflow admitted into the aerosol-generating article via the ventilation zone (ventilation airflow) and the sum of the aerosol airflow and the ventilation airflow. The greater the ventilation level, the higher the dilution of the aerosol flow delivered to the consumer.

[0132] Preferably, an aerosol-generating article in accordance with the present disclosure may have a ventilation level of at least about 10 percent, more preferably at least about 15 percent, even more preferably at least about 20 percent. In particularly preferred embodiments, an aerosolgenerating article in accordance with the present disclosure has a ventilation level of at least about 25 percent. For example, an aerosol-generating article in accordance with the present disclosure may have a ventilation level of at least 30 percent, or at least 35 percent. The aerosol-generating article preferably has a ventilation level of less than about 60 percent. An aerosol-generating article in accordance with the present disclosure preferably has a ventilation level of less than or equal to about 45 percent. More preferably, an aerosol-generating article in accordance with the present disclosure has a ventilation level of less than or equal to about 40 percent, even more preferably less than or equal to about 35 percent.

[0133] In some examples, the aerosol-generating article has a ventilation level from about 20 percent to about 60 percent, preferably from about 20 percent to about 45 percent, more preferably from about 20 percent to about 40 percent. In other examples, the aerosol-generating article has a ventilation level from about 25 percent to about 60 percent, preferably from about 25 percent to about 45 percent, more preferably from about 25 percent to about 40 percent. In further examples, the aerosol-generating article has a ventilation level from about 30 percent to about 60 percent, preferably from about 30 percent to about 45 percent, more preferably from about 30 percent to about 40 percent. In further examples, the aerosol-generating article has a ventilation level from about 35 percent to about 60 percent, preferably from about 35 percent to about 45 percent, more preferably from about 35 percent to about 40 percent.

[0134] In particularly preferred examples, the aerosol-generating article has a ventilation level from about 28 percent to about 42 percent, from about 30 percent to about 42 percent, from about 35 percent to about 42 percent. In some particularly preferred embodiments, the aerosolgenerating article has a ventilation level of about 30 percent. In another particularly preferred embodiment, the aerosol-generating article has a ventilation level of about 40 percent.

[0135] Without wishing to be bound by theory, the inventors have found that the temperature drop caused by the admission of cooler, external air into the hollow tubular element via the ventilation zone may have an advantageous effect on the nucleation and growth of aerosol particles.

[0136] Formation of an aerosol from a gaseous mixture containing various chemical species depends on a delicate interplay between nucleation, evaporation, and condensation, as well as coalescence, all the while accounting for variations in vapour concentration, temperature, and velocity fields. The so-called classical nucleation theory is based on the assumption that a fraction of the molecules in the gas phase are large enough to stay coherent for long times with sufficient probability (for example, a probability of one half). These molecules represent some kind of a critical, threshold molecule clusters among transient molecular aggregates, meaning that, on average, smaller molecule clusters are likely to disintegrate rather quickly into the gas phase, while larger clusters are, on average, likely to grow. Such critical cluster is identified as the key nucleation core from which droplets are expected to grow due to condensation of molecules from the vapour. It is assumed that virgin droplets that just nucleated emerge with a certain original diameter, and then may grow by several orders of magnitude. This is facilitated and may be enhanced by rapid cooling of the surrounding vapour, which induces condensation. In this connection, it helps to bear in mind that evaporation and condensation are two sides of one same mechanism, namely gas-liquid mass transfer. While evaporation relates to net mass transfer from the liquid droplets to the gas phase, condensation is net mass transfer from the gas phase to the droplet phase. Evaporation (or condensation) will make the droplets shrink (or grow), but it will not change the number of droplets.

[0137] In this scenario, which may be further complicated by coalescence phenomena, the temperature and rate of cooling can play a critical role in determining how the system responds. In general, different cooling rates may lead to significantly different temporal behaviours as concerns the formation of the liquid phase (droplets), because the nucleation process is typically nonlinear. Without wishing to be bound by theory, it is hypothesised that cooling can cause a rapid increase in the number concentration of droplets, which is followed by a strong, short-lived increase in this growth (nucleation burst). This nucleation burst would appear to be more significant at lower temperatures. Further, it would appear that higher cooling rates may favour an earlier onset of nucleation. By contrast, a reduction of the cooling rate would appear to have a favourable effect on the final size that the aerosol droplets ultimately reach.

[0138] Therefore, the rapid cooling induced by the admission of external air into the hollow tubular element via the ventilation zone can be favourably used to favour nucleation and growth of aerosol droplets. However, at the same time, the admission of external air into the hollow tubular element has the immediate drawback of diluting the aerosol stream delivered to the consumer.

[0139] The inventors have surprisingly found how the favourable effect of enhanced nucleation promoted by the rapid cooling induced by the introduction of ventilation air into the article is capable of significantly countering the less desirable effects of dilution. As such, satisfactory values of aerosol delivery are consistently achieved with aerosol-generating articles in accordance with the present disclosure.

[0140] This is particularly advantageous with “short” aerosol-generating articles, such as ones wherein a length of the rod of aerosol-generating substrate is less than about 40 millimetres, preferably less than 25 millimetres, even more preferably less than 20 millimetres, or wherein an overall length of the aerosol-generating article is less than about 70 millimetres, preferably less than about 60 millimetres, even more preferably less than 50 millimetres. As will be appreciated, in such aerosol-generating articles, there is little time and space for the aerosol to form and for the particulate phase of the aerosol to become available for delivery to the consumer.

[0141] As described briefly above, according to the present disclosure there is provided an aerosol-generating article comprising an aerosol-generating substrate, such as for example in the form of a rod of aerosol-generating substrate.

[0142] The aerosol-generating substrate may be a solid aerosol-generating substrate.

[0143] The aerosol-generating substrate may be circumscribed by a wrapper.

[0144] The aerosol-generating substrate may comprise nicotine. The aerosol-generating substrate may comprise natural nicotine, or synthetic nicotine, or a combination of natural nicotine and synthetic nicotine. The aerosol-generating substrate may comprise a plant material, such as tobacco plant material.

[0145] The aerosol-generating substrate may comprise non-tobacco plant material. Examples of suitable non-tobacco plant materials include cannabis material, ginger material, eucalyptus material, clove material, and star anise material.

[0146] Particularly suitable types of materials for use in the aerosol-generating substrate are described below and include, for example, tobacco cut filler, homogenised tobacco material such as cast leaf, aerosol-generating films and gel compositions.

[0147] The aerosol-generating substrate preferably comprises an aerosol former. Suitable aerosol formers are for example: polyhydric alcohols such as, for example, triethylene glycol, 1 ,3-butanediol, propylene glycol and glycerine; esters of polyhydric alcohols such as, for example, glycerol mono-, di- or triacetate; aliphatic esters of mono-, di- or polycarboxylic acids such as, for example, dimethyl dodecanedioate and dimethyl tetradecanedioate; and combinations thereof.

[0148] Preferably, the aerosol former comprises one or more of glycerine and propylene glycol. The aerosol former may consist of glycerine or propylene glycol or of a combination of glycerine and propylene glycol.

[0149] In certain embodiments, the aerosol-generating substrate preferably comprises at least 5 percent by weight of aerosol former on a dry weight basis of the aerosol-generating substrate, more preferably at least 10 percent by weight on a dry weight basis, more preferably at least 15 percent by weight on a dry weight basis. In such embodiments, the aerosol-generating substrate preferably comprises no more than 30 percent by weight of aerosol former on a dry weight basis of the aerosol-generating substrate, more preferably no more than 25 percent by weight on a dry weight basis, more preferably no more than 20 percent by weight on a dry weight basis. For example, the aerosol former content of the aerosol-generating substrate may be between 5 percent and 30 percent by weight, or between 10 percent and 25 percent by weight, or between about 15 percent and about 20 percent by weight, on a dry weight basis. In such embodiments, the aerosol former content is therefore relatively low.

[0150] In other embodiments, the aerosol-generating substrate preferably comprises at least 40 percent by weight of aerosol former on a dry weight basis of the aerosol-generating substrate, more preferably at least 45 percent by weight on a dry weight basis, more preferably at least 50 percent by weight on a dry weight basis. In such embodiments, the aerosol-generating substrate preferably comprises no more than 80 percent by weight of aerosol former on a dry weight basis of the aerosol-generating substrate, more preferably no more than 75 percent by weight on a dry weight basis, more preferably no more than 70 percent by weight on a dry weight basis. For example, the aerosol former content of the aerosol-generating substrate may be between 40 percent and 80 percent by weight, or between 45 percent and 75 percent by weight, or between about 50 percent and about 70 percent by weight, on a dry weight basis. In such embodiments, the aerosol former content is therefore relatively high.

[0151] In some preferred embodiments, the aerosol-generating substrate comprises tobacco material. For example, the aerosol-generating substrate may comprise shredded tobacco material. For example, the shredded tobacco material may be in the form of cut filler, as described in more detail below. Alternatively, the shredded tobacco material may be in the form of a shredded sheet of homogenised tobacco material. Suitable homogenised tobacco materials for use in the present disclosure are described below.

[0152] Within the context of the present specification, the term “cut filler” is used to describe to a blend of shredded plant material, such as tobacco plant material, including, in particular, one or more of leaf lamina, processed stems and ribs, homogenised plant material.

[0153] The cut filler suitable to be used with the present disclosure generally may resemble cut filler used for conventional smoking articles. The cut width of the cut filler preferably may be between 0.3 millimetres and 2.0 millimetres, or between 0.5 millimetres and 1.2 millimetres, or between 0.6 millimetres and 0.9 millimetres.

[0154] Preferably, the strands have a length of between about 10 millimetres and about 40 millimetres before the strands are collated to form the rod of aerosol-generating substrate.

[0155] Preferably, the cut filler is soaked with the aerosol former. Soaking the cut filler can be done by spraying or by other suitable application methods. Preferably, the aerosol former in the cut filler comprises one or more of glycerol and propylene glycol. The aerosol former may consist of glycerol or propylene glycol or of a combination of glycerol and propylene glycol.

[0156] In other preferred embodiments, the aerosol-generating substrate comprises homogenised plant material, such as homogenised non-tobacco plant material and homogenised tobacco material. Preferably, the aerosol-generating substrate comprises homogenised tobacco material.

[0157] As used herein, the term “homogenised plant material” encompasses any plant material formed by the agglomeration of particles of plant. For example, sheets or webs of homogenised tobacco material for the aerosol-generating substrates of the present disclosure may be formed by agglomerating particles of tobacco material obtained by pulverising, grinding or comminuting plant material and optionally one or more of tobacco leaf lamina and tobacco leaf stems. The homogenised plant material may be produced by casting, extrusion, paper making processes or other any other suitable processes known in the art.

[0158] The homogenised plant material can be provided in any suitable form.

[0159] In some embodiments, the homogenised plant material may be in the form of one or more sheets. As used herein with reference to the invention, the term “sheet” describes a laminar element having a width and length substantially greater than the thickness thereof.

[0160] The homogenised plant material may be in the form of a plurality of pellets or granules. The homogenised plant material may be in the form of a plurality of strands, strips or shreds. As used herein, the term “strand” describes an elongate element of material having a length that is substantially greater than the width and thickness thereof.

[0161] The aerosol former content of the homogenised plant material, such as homogenised tobacco material, is preferably within the ranges defined above for aerosol-generating substrate having a relatively low aerosol former content.

[0162] In other preferred embodiments, the aerosol-generating substrate is in the form of an aerosol-generating film comprising a cellulosic based film-forming agent, nicotine and the aerosol former. The aerosol-generating film may further comprise a cellulose based strengthening agent. The aerosol-generating film may further comprise water, preferably 30 percent by weight of less of water.

[0163] As used herein, the term “film” is used to describe a solid laminar element having a thickness that is less than the width or length thereof. The film may be self-supporting.

[0164] In the context of the present disclosure the term “cellulose based film-forming agent” is used to describe a cellulosic polymer capable, by itself or in the presence of an auxiliary thickening agent, of forming a continuous film. Preferably, the cellulose based film-forming agent is selected from the group consisting of hydroxypropyl methylcellulose (HPMC), methylcellulose (MC), ethyl cellulose (EC), hydroxyethyl methyl cellulose (HEMC), hydroxyethyl cellulose (HEC), hydroxypropyl cellulose (HPC), and combinations thereof. In particularly preferred embodiments, the cellulose based film-forming agent is HPMC.

[0165] The aerosol former content of the aerosol-generating film is within the ranges defined above for aerosol-generating substrates having a relatively high aerosol former content.

[0166] Suitable aerosol-generating films for use as the aerosol-generating substrate of aerosolgenerating articles according to the invention are described in WO-A-2020 / 207733 and WO-A-2022 / 074157.

[0167] Preferably, the aerosol-generating film comprises between 0.5 percent and 10 percent by weight of nicotine, or between 1 percent and 8 percent by weight of nicotine, or between 2 percent and 6 percent by weight of nicotine, on a dry weight basis.

[0168] The aerosol-generating film may be a substantially tobacco-free aerosol-generating film. In alternative embodiments of the invention, the aerosol-generating substrate may comprise a gel composition that includes nicotine, at least one gelling agent and the aerosol former. The gel composition is preferably substantially tobacco free.

[0169] The preferred weight ranges for nicotine in the gel composition are the same as those defined above in relation to aerosol-generating films.

[0170] Suitable gel compositions for use as the aerosol-generating substrate of aerosolgenerating articles according to the invention are described in WO-A-2021 / 170642. The gel composition preferably comprises at least 50 percent by weight of aerosol former, more preferably at least 60 percent by weight, more preferably at least 70 percent by weight of aerosol former, on a dry weight basis. The gel composition may comprise up to 80 percent by weight of aerosol former. The aerosol former in the gel composition is preferably glycerol.

[0171] As will become apparent from the following description of several examples of aerosolgenerating articles according to the present disclosure, the aerosol-generating substrate is preferably in the form of a sheet, such as for example a sheet of homogenised plant material. In particular, the aerosol-generating substrate is preferably in the form of a sheet of homogenised tobacco material.

[0172] The rod of aerosol-generating substrate preferably has an external diameter that is approximately equal to the external diameter of the aerosol-generating article. The rod of aerosolgenerating substrate preferably has an external diameter that is approximately equal to the external diameter of the hollow tubular element. The rod of aerosol-generating substrate preferably has an external diameter that is approximately equal to the external diameter of the upstream element.

[0173] The rod of aerosol-generating substrate may have an external diameter of at least 4 millimetres. Preferably, the rod of aerosol-generating substrate has an external diameter of at least 5 millimetres. More preferably, the rod of aerosol-generating substrate has an external diameter of at least 6 millimetres. Even more preferably, the rod of aerosol-generating substrate has an external diameter of at least 7 millimetres.

[0174] Preferably, the rod of aerosol-generating substrate has an external diameter of less than or equal to about 12 millimetres. More preferably, the rod of aerosol-generating substrate has an external diameter of less than or equal to about 10 millimetres. Even more preferably, the rod of aerosol-generating substrate has an external diameter of less than or equal to about 8 millimetres.

[0175] In some embodiments, the rod of aerosol-generating substrate has an external diameter from about 5 millimetres to about 12 millimetres, preferably from about 6 millimetres to about 12 millimetres, more preferably from about 7 millimetres to about 12 millimetres. In other embodiments, the rod of aerosol-generating substrate has an external diameter from about 5 millimetres to about 10 millimetres, preferably from about 6 millimetres to about 10 millimetres, more preferably from about 7 millimetres to about 10 millimetres. In further embodiments, the rod of aerosol-generating substrate has an external diameter from about 5 millimetres to about 8 millimetres, preferably from about 6 millimetres to about 8 millimetres, more preferably from about 7 millimetres to about 8 millimetres.

[0176] The rod of aerosol-generating substrate may have an external diameter of about 7.05 millimetres.

[0177] The rod of aerosol-generating substrate may have a length of at least 8 millimetres, preferably at least 9 millimetres, more preferably at least 10 millimetres. The rod of aerosol-generating substrate may have a length of less than or equal to 16 millimetres, preferably less than or equal to 14 millimetres, more preferably less than or equal to 12 millimetres.

[0178] The rod of aerosol-generating substrate may have a length of between 8 millimetres and 16 millimetres, between 8 millimetres and 14 millimetres, or between 8 millimetres and 12 millimetres. The rod of aerosol-generating substrate may have a length of between 9 millimetres and 16 millimetres, between 9 millimetres and 14 millimetres, or between 9 millimetres and 12 millimetres. The rod of aerosol-generating substrate may have a length of between 10 millimetres and 16 millimetres, between 10 millimetres and 14 millimetres, or between 10 millimetres and 12 millimetres. Preferably, the rod of aerosol-generating substrate has a length of 11 millimetres.

[0179] The aerosol-generating article may comprise an internal heater. The internal heater is arranged inside at least part of the rod of aerosol-generating substrate.

[0180] The internal heater may be a susceptor.

[0181] The aerosol-generating article may comprise a susceptor. The susceptor may be located within the rod of aerosol-generating substrate.

[0182] The susceptor may be arranged substantially longitudinally within the rod of aerosolgenerating substrate. That is, a longitudinal axis of the susceptor may be approximately parallel to a longitudinal axis of the rod of aerosol-generating substrate. For example, a longitudinal axis of the susceptor may be within plus or minus 10 degrees of parallel to a longitudinal axis of the rod of aerosol-generating substrate.

[0183] The susceptor may be arranged centrally within the rod of aerosol-generating substrate. The susceptor may extend along a longitudinal axis of the rod of aerosol-generating substrate.

[0184] As used herein with reference to the present disclosure, the term “susceptor” refers to an element comprising a material that can convert electromagnetic energy into heat. When located within a fluctuating electromagnetic field, eddy currents induced in the susceptor cause heating of the susceptor. As the susceptor is located in thermal contact with the aerosol-generating substrate, the aerosol-generating substrate is heated by the susceptor.

[0185] Suitable susceptors for use in the aerosol-generating substrate of aerosol-generating articles according to the present disclosure are described in WO-A-2021 / 170673.

[0186] The susceptor may be formed from any material that can be inductively heated to a temperature sufficient to generate an aerosol from the aerosol-generating substrate. Preferred susceptors comprise a metal or carbon.

[0187] A preferred susceptor may comprise or consist of a ferromagnetic material, for example a ferromagnetic alloy, ferritic iron, or a ferromagnetic steel or stainless steel. A suitable susceptor may be, or comprise, aluminium. Preferred susceptors may be formed from 400 series stainless steels, for example grade 410, or grade 420, or grade 430 stainless steel. Different materials will dissipate different amounts of energy when positioned within electromagnetic fields having similar values of frequency and field strength. Thus, parameters of the susceptor such as material type, length, width, and thickness may all be altered to provide a desired power dissipation within a known electromagnetic field. Preferred susceptors may be heated to a temperature in excess of 250 degrees Celsius.

[0188] Suitable susceptors may comprise a non-metallic core with a metal layer disposed on the non-metallic core, for example metallic tracks formed on a surface of a ceramic core. A susceptor may have a protective external layer, for example a protective ceramic layer or protective glass layer encapsulating the susceptor. The susceptor may comprise a protective coating formed by a glass, a ceramic, or an inert metal, formed over a core of susceptor material.

[0189] In an aerosol-generating article according to the present disclosure, the susceptor may be in the form of a strip or blade.

[0190] In an aerosol-generating article according to the present disclosure, a thickness of the susceptor may be at least 50 micrometres.

[0191] Preferably, a thickness of the susceptor is at least 55 micrometres. More preferably, a thickness of the susceptor is at least 60 micrometres.

[0192] In an aerosol-generating article according to the present disclosure, a thickness of the susceptor may be less than or equal to 80 micrometres. Preferably, a thickness of the susceptor is less than or equal to 75 micrometres. More preferably, a thickness of the susceptor is less than or equal to 70 micrometres.

[0193] In some aerosol-generating articles according to the present disclosure, a thickness of the susceptor is from 50 micrometres to 80 micrometres, preferably from 50 micrometres to 75 micrometres, more preferably from 50 micrometres to 70 micrometres.

[0194] In other aerosol-generating articles according to the present disclosure, a thickness of the susceptor is from 55 micrometres to 80 micrometres, preferably from 55 micrometres to 75 micrometres, more preferably from 55 micrometres to 70 micrometres.

[0195] In further aerosol-generating articles according to the present disclosure, a thickness of the susceptor is from 60 micrometres to 80 micrometres, preferably from 60 micrometres to 75 micrometres, more preferably from 60 micrometres to 70 micrometres.

[0196] In an aerosol-generating article according to the present disclosure, a length of the susceptor may be at least 50 percent of a length of the rod of aerosol-generating substrate.

[0197] Preferably, a length of the susceptor is at least 75 percent of a length of the rod of aerosolgenerating substrate. More preferably, a length of the susceptor is at least 95 percent of a length of the rod of aerosol-generating substrate. Even more preferably, a length of the susceptor is substantially equal to a length of the rod of aerosol-generating substrate.

[0198] Preferably, the susceptor has a width between 3 millimetres and 5 millimetres. For example, the susceptor may have a width of 4 millimetres. Aerosol-generating articles according to the present disclosure comprise an upstream section at a location upstream of the rod of aerosol-generating substrate.

[0199] The upstream section may extend from the upstream end of the aerosol-generating article to the upstream end of the rod of aerosol-generating substrate. The upstream element may extend the entire length of the upstream section.

[0200] The upstream element is arranged immediately upstream of the rod of aerosol-generating substrate and abuts the upstream end of the rod of aerosol-generating substrate. The upstream element may extend from the upstream end of the aerosol-generating article. The upstream element may be located at the upstream end of the aerosol-generating article. The upstream end of the upstream element may define the upstream end of the aerosol-generating article. The upstream element may extend from the upstream end of the aerosol-generating article to the upstream end of the rod of aerosol-generating substrate.

[0201] The upstream element advantageously prevents direct physical contact with the upstream end of the aerosol-generating substrate. In particular, where the aerosol-generating substrate comprises a susceptor, the upstream element may prevent direct physical contact with the upstream end of the susceptor. This helps to prevent the displacement or deformation of the susceptor during handling or transport of the aerosol-generating article. This in turn helps to secure the form and position of the susceptor. Furthermore, the presence of an upstream element helps to prevent any loss of the aerosol-generating substrate, which may be advantageous, for example, if the aerosol-generating substrate contains particulate plant material.

[0202] The upstream element may also provide an improved appearance to the upstream end of the aerosol-generating article. Furthermore, if desired, the upstream element may be used to provide information on the aerosol-generating article, such as information on brand, flavour, content, or details of the aerosol-generating device that the article is intended to be used with.

[0203] The upstream element may be in the form of a tube defining a longitudinal flow channel that is substantially empty. The longitudinal flow channel may be substantially exclusively defined by the tube.

[0204] Preferably, the upstream element is a plug element. The upstream element may be a porous plug element. The upstream element may be a solid cylindrical plug element having a filled cross-section.

[0205] An upstream element in the form of a plug element may have improved rigidity compared to a tubular element.

[0206] The plug element may be referred to as a ‘plain’ element. The plug element may be porous, as described above, but does not have a tubular form defining a longitudinal flow channel that is substantially empty. The plug element may have a substantially uniform transverse crosssection. Preferably, a porous plug element does not alter the resistance to draw of the aerosolgenerating article.

[0207] Preferably, the upstream element has a porosity of at least about 50 percent in the longitudinal direction of the aerosol-generating article. More preferably, the upstream element has a porosity of between about 50 percent and about 90 percent in the longitudinal direction. The porosity of the upstream element in the longitudinal direction is defined by the ratio of the cross-sectional area of material forming the upstream element and the internal cross-sectional area of the aerosol-generating article at the position of the upstream element.

[0208] The upstream element may be made of a porous material or may comprise a plurality of openings. This may, for example, be achieved through laser perforation. Preferably, the plurality of openings is distributed homogeneously over the cross-section of the upstream element.

[0209] The porosity or permeability of the upstream element may advantageously be varied in order to provide a desirable overall resistance to draw of the aerosol-generating article.

[0210] The upstream element may comprise cellulose acetate (such as a solid plug of cellulose acetate), paper or viscose. Preferably, the upstream element comprises paper or viscose. The upstream element may be made of or formed from cellulose acetate, paper or viscose. Preferably, the upstream element is made of or formed from paper or viscose.

[0211] The upstream element may be formed of a non-woven material, such as an airlaid nonwoven material. The airlaid non-woven material may comprise a biodegradable material. The airlaid non-woven material may comprise cellulose fibres. The airlaid non-woven material may comprise at least 90 percent by weight cellulose. The formation of an upstream element from an airlaid non-woven material enables the manufacture of the upstream element from more sustainable, for example, natural or biodegradable materials, without compromising on the functional and mechanical properties of the upstream element.

[0212] Preferably, a content of cellulose acetate in the upstream element may be less than or equal to 15 percent by weight. Preferably, a content of cellulose acetate in the upstream element is less than or equal to 10 percent by weight. More preferably, a content of cellulose acetate in the upstream element is less than or equal to 5 percent by weight. Even more preferably, the upstream element is substantially free of cellulose acetate.

[0213] The upstream element may comprise a crimped sheet or a convoluted sheet.

[0214] The upstream element may be in the form of a plug element comprising a tubular portion defining an inner region of the upstream element and a crimped sheet or a convoluted sheet located in the inner region. The crimped sheet or the convoluted sheet may define a plurality of longitudinally extending channels in the inner region.

[0215] As an example, the upstream element may comprise a crimped sheet of paper or a convoluted sheet of paper. The upstream element preferably has an external diameter that is approximately equal to the external diameter of the aerosol-generating article. The upstream element preferably has an external diameter that is approximately equal to the external diameter of the rod of aerosolgenerating substrate.

[0216] The external diameter of the upstream element may be between about 5 mm and about 12 millimetres. The external diameter of the upstream element may be between about 5 mm and about 10 mm. The external diameter of the upstream element may be between about 6 mm and about 8 mm. The external diameter of the upstream element may be between about 7 mm and about 8 mm. The external diameter of the upstream element may be about 7.1 mm. The external diameter of the upstream element may be about 7.05 mm.

[0217] The upstream element may have a length of at least 2 millimetres, preferably at least 3 millimetres, more preferably at least 4 millimetres.

[0218] The upstream element may have a length of less than or equal to 10 millimetres, preferably less than or equal to 8 millimetres, more preferably less than or equal to 6 millimetres.

[0219] The upstream element may have a length of between 2 millimetres and 10 millimetres, between 2 millimetres and 8 millimetres, or between 2 millimetres and 6 millimetres. The upstream element may have a length of between 3 millimetres and 10 millimetres, between 3 millimetres and 8 millimetres, or between 3 millimetres and 6 millimetres. The upstream element may have a length of between 4 millimetres and 10 millimetres, between 4 millimetres and 8 millimetres, or between 4 millimetres and 6 millimetres.

[0220] Preferably, the upstream element has a length of 5 millimetres.

[0221] A ratio of the length of the mouthpiece element to the length of the upstream element may be at least 1.8, preferably at least 2, more preferably at least 2.4.

[0222] A ratio of the length of the mouthpiece element to the length of the upstream element may be less than or equal to 4, preferably less than or equal to 3.5, more preferably less than or equal to 3.

[0223] A ratio of the length of the mouthpiece element to the length of the upstream element may be between 1.8 and 4, between 1.8 and 3.5, or between 1.8 and 3. A ratio of the length of the mouthpiece element to the length of the upstream element may be between 2 and 4, between 2 and 3.5, or between 2 and 3. A ratio of the length of the mouthpiece element to the length of the upstream element may be between 2.2 and 4, between 2.2 and 3.5, or between 2.2 and 3.

[0224] The mouthpiece element being substantially longer than the upstream element may provide a user with a mechanism to identify the upstream and downstream ends of the aerosolgenerating article, this may be due to a difference in the hardness of the aerosol-generating article at the mouthpiece element and at the upstream element.

[0225] The ratio of the length of the mouthpiece element to the length of the upstream element described herein provides a desired balance between the filtration level of the aerosol-generating article and the ease at identifying the upstream and downstream ends of the aerosol-generating article.

[0226] The aerosol-generating article may have a length from about 35 millimetres to about 100 millimetres.

[0227] Preferably, an overall length of an aerosol-generating article is at least about 38 millimetres. More preferably, an overall length of an aerosol-generating article is at least about 40 millimetres. Even more preferably, an overall length of an aerosol-generating article is at least about 42 millimetres.

[0228] An overall length of an aerosol-generating article is preferably less than or equal to 70 millimetres. More preferably, an overall length of an aerosol-generating article is preferably less than or equal to 60 millimetres. Even more preferably, an overall length of an aerosol-generating article in is preferably less than or equal to 50 millimetres.

[0229] In some embodiments, an overall length of the aerosol-generating article is preferably from about 38 millimetres to about 70 millimetres, more preferably from about 40 millimetres to about 70 millimetres, even more preferably from about 42 millimetres to about 70 millimetres. In other embodiments, an overall length of the aerosol-generating article is preferably from about 38 millimetres to about 60 millimetres, more preferably from about 40 millimetres to about 60 millimetres, even more preferably from about 42 millimetres to about 60 millimetres. In further embodiments, an overall length of the aerosol-generating article is preferably from about 38 millimetres to about 50 millimetres, more preferably from about 40 millimetres to about 50 millimetres, even more preferably from about 42 millimetres to about 50 millimetres.

[0230] Preferably, an overall length of the aerosol-generating article is about 45 millimetres. The aerosol-generating article may have an external diameter of at least 4 millimetres. Preferably, the aerosol-generating article has an external diameter of at least 5 millimetres. More preferably, the aerosol-generating article has an external diameter of at least 6 millimetres. Even more preferably, the aerosol-generating article has an external diameter of at least 7 millimetres.

[0231] Preferably, the aerosol-generating article has an external diameter of less than or equal to about 12 millimetres. More preferably, the aerosol-generating article has an external diameter of less than or equal to about 10 millimetres. Even more preferably, the aerosol-generating article has an external diameter of less than or equal to about 8 millimetres.

[0232] In some embodiments, the aerosol-generating article has an external diameter from about 5 millimetres to about 12 millimetres, preferably from about 6 millimetres to about 12 millimetres, more preferably from about 7 millimetres to about 12 millimetres. In other embodiments, the aerosol-generating article has an external diameter from about 5 millimetres to about 10 millimetres, preferably from about 6 millimetres to about 10 millimetres, more preferably from about 7 millimetres to about 10 millimetres. In further embodiments, the aerosol-generating article has an external diameter from about 5 millimetres to about 8 millimetres, preferably from about 6 millimetres to about 8 millimetres, more preferably from about 7 millimetres to about 8 millimetres.

[0233] Preferably, the aerosol-generating article has an external diameter of about 7.2 millimetres. The aerosol-generating article may have an external diameter of about 7.18 millimetres.

[0234] The aerosol-generating article may comprise one or more wrappers circumscribing one or more of the upstream element, the rod of aerosol-generating substrate, the hollow tubular element and the mouthpiece element so as to assemble them into the aerosol-generating article.

[0235] The expression “one or more wrappers” is used herein to encompass different possible arrangements wherein one or more of the components forming the aerosol-generating article may be individually wrapped, and some combination of wrappers and tipping paper are used to attach the various individually wrapped or unwrapped components so as to form the aerosol-generating article.

[0236] The aerosol-generating article may comprise a tipping wrapper circumscribing the hollow tubular element and the mouthpiece element. The aerosol-generating article may comprise a tipping wrapper circumscribing the hollow tubular element along at least a portion of the length of the hollow tubular element and the mouthpiece element along the entire length of the mouthpiece element. The tipping wrapper may circumscribe the hollow tubular element along a portion of the length of the hollow tubular element and the mouthpiece element along the entire length of the mouthpiece element. In this way, the tipping wrapper joins the mouthpiece element to the hollow tubular element.

[0237] The tipping wrapper may extend from the downstream end of the mouthpiece element to a location along the hollow tubular element.

[0238] The tipping wrapper may have a length of at least 14 millimetres, at least 16 millimetres, at least 18 millimetres, or at least 20 millimetres.

[0239] The tipping wrapper may have a length of less than or equal to 30 millimetres, less than or equal to 26 millimetres, or less than or equal to 22 millimetres.

[0240] The tipping wrapper may have a length of between 14 millimetres and 30 millimetres, between 14 millimetres and 26 millimetres, or between 14 millimetres and 22 millimetres. The tipping wrapper may have a length of between 16 millimetres and 30 millimetres, between 16 millimetres and 26 millimetres, or between 16 millimetres and 22 millimetres. The tipping wrapper may have a length of between 18 millimetres and 30 millimetres, between 18 millimetres and 26 millimetres, or between 18 millimetres and 22 millimetres. The tipping wrapper may have a length of between 20 millimetres and 30 millimetres, between 20 millimetres and 26 millimetres, or between 20 millimetres and 22 millimetres.

[0241] The tipping wrapper preferably has a length of about 20 millimetres. The tipping wrapper may be formed from paper. Such a tipping wrapper may be referred to as a tipping paper.

[0242] The ventilation zone may be provided at a location along the tipping wrapper. Where the ventilation zone is at a location along the tipping wrapper, the ventilation zone may comprise a plurality of openings or perforations through the tipping wrapper.

[0243] Where the ventilation zone is at a location along both the tipping wrapper and the hollow tubular element, the ventilation zone may comprise a plurality of openings or perforations through the tipping wrapper and the peripheral wall of the hollow tubular element, the plurality of openings or perforations through the tipping wrapper being aligned with the perforations through the peripheral wall of the hollow tubular element.

[0244] As discussed above, the present disclosure also relates to an aerosol-generating system comprising an aerosol-generating article as discussed herein and an aerosol-generating device comprising a heating arrangement configured to heat at least a portion of the aerosol-generating substrate to generate an aerosol.

[0245] The aerosol-generating device has a distal end and a mouth end. The aerosol-generating device may comprise a body. The body or housing of the aerosol-generating device may define a device cavity for removably receiving the aerosol-generating article at the mouth end of the device.

[0246] The device cavity may be referred to as the heating chamber of the aerosol-generating device. The device cavity may extend between a distal, or upstream, end and a mouth, or proximal or downstream, end. The distal, or upstream, end of the device cavity may be a closed end and the mouth, or proximal or downstream, end of the device cavity may be an open end. An aerosolgenerating article may be inserted into the device cavity, or heating chamber, via the open end of the device cavity. The device cavity may be cylindrical in shape so as to conform to the same shape of an aerosol-generating article.

[0247] The expression “received within” may refer to the fact that a component or element is fully or partially received within another component or element. For example, the expression “aerosolgenerating article is received within the device cavity” refers to the aerosol-generating article being fully or partially received within the device cavity of the aerosol-generating article. When the aerosol-generating article is received within the device cavity, the aerosol-generating article may abut the distal end of the device cavity. When the aerosol-generating article is received within the device cavity, the aerosol-generating article may be in substantial proximity to the distal end of the device cavity. The distal end of the device cavity may be defined by an end-wall.

[0248] The length of the device cavity (or heating chamber) may be the same as or greater than the combined length of the upstream section or element and rod of aerosol-generating substrate. The length of the device cavity may be such that the downstream section or a portion thereof is configured to protrude from the device cavity, when the aerosol-generating article is received within the device cavity. The length of the device cavity may be such that a portion of the downstream section (such as the hollow tubular element or mouthpiece element) is configured to protrude from the device cavity, when the aerosol-generating article is received within the device cavity. The length of the device cavity may be such that a portion of the downstream section (such as the hollow tubular element or mouthpiece element) is configured to be received within the device cavity, when the aerosol-generating article received within the device cavity.

[0249] Where the aerosol-generating article comprises a ventilation zone, the aerosol-generating device and the aerosol-generating article may be configured such that the ventilation zone of the aerosol-generating article is arranged to be outside of the heating chamber when the aerosolgenerating article is received within the heating chamber during use of the aerosol-generating system. The ventilation zone of the aerosol-generating article may be arranged to be exposed when the aerosol-generating article is received within the heating chamber of the aerosolgenerating device during use of the aerosol-generating system.

[0250] The heater arrangement extends from an upstream or distal end to a downstream or proximal end defining a heating zone. The heater arrangement may have substantially the same length as the rod of aerosol-generating substrate. This may be such that when the aerosolgenerating article is received within the heating chamber, the entire length of the rod of aerosolgenerating substrate is received within the heating zone to provide optimal heating of the rod of aerosol-generating substrate.

[0251] The heater arrangement may have a length substantially the same as the length of the rod of aerosol-generating substrate.

[0252] The heater arrangement may comprise a resistive heating element or an induction element. The induction element may be an inductor coil.

[0253] The aerosol-generating device may comprise a power supply. The power supply may be a DC power supply. In some embodiments, the power supply is a battery.

[0254] The aerosol-generating device may comprise a controller to control the supply of power from the power supply to the heater arrangement.

[0255] Below, there is provided a non-exhaustive list of non-limiting examples. Any one or more of the features of these examples may be combined with any one or more features of another example, or embodiment, or aspect described herein.

[0256] EX1 : An aerosol-generating article for producing an inhalable aerosol upon heating, the aerosol-generating article comprising: a rod of aerosol-generating substrate; an upstream element located upstream of the rod of aerosol-generating substrate and abutting the upstream end of the rod of aerosol-generating substrate; and a downstream section arranged downstream of the rod of aerosol-generating substrate, the downstream section comprising: a hollow tubular element abutting the downstream end of the rod of aerosol-generating substrate; and a mouthpiece element located downstream of the hollow tubular element and abutting the downstream end of the hollow tubular element.

[0257] EX2: An aerosol-generating article according to EX1, wherein the hollow tubular element is formed from cardboard.

[0258] EX3: An aerosol-generating article according to EX1 or EX2, wherein the wall thickness of the hollow tubular element is less than or equal to 1 millimetre.

[0259] EX4: An aerosol-generating article according to any one of EX1 to EX3, wherein the hollow tubular element has a substantially constant internal diameter along the entire length of the hollow tubular element.

[0260] EX5: An aerosol-generating article according to any one of EX1 to EX4, wherein a ratio between the wall thickness of the hollow tubular element to the internal diameter of the hollow tubular element is less than or equal to 0.1.

[0261] EX6: An aerosol-generating article according to any one of EX1 to EX5, wherein the length of the hollow tubular element is at least 12 millimetres.

[0262] EX7: An aerosol-generating article according to any one of EX1 to EX6, wherein the length of the hollow tubular element is less than or equal to 22 millimetres.

[0263] EX8: An aerosol-generating article according to any one of EX1 to EX7, wherein a ratio of the length of the rod of aerosol-generating substrate to the length of the hollow tubular element is less than or equal to 1.

[0264] EX9: An aerosol-generating article according to any one of EX1 to EX8, wherein a ratio of the length of the rod of aerosol-generating substrate to the length of the hollow tubular element is at least 0.3.

[0265] EX10: An aerosol-generating article according to any one of EX1 to EX9, wherein a ratio of the length of the hollow tubular element and the overall length of the aerosol-generating article is less than or equal to 0.6.

[0266] EX11: An aerosol-generating article according to any one of EX1 to EX10, wherein a ratio of the length of the hollow tubular element and the overall length of the aerosol-generating article is at least 0.2.

[0267] EX12: An aerosol-generating article according to any one of EX1 to EX11, wherein the mouthpiece element is made of or formed from cellulose acetate, paper, viscose, or lyocell; preferably paper, viscose, or lyocell.

[0268] EX13: An aerosol-generating article according to any one of EX1 to EX12 further comprising a capsule located inside the mouthpiece element.

[0269] EX14: An aerosol-generating article according to any one of EX1 to EX13, wherein the mouthpiece element has a length of at least 6 millimetres.

[0270] EX15: An aerosol-generating article according to any one of EX1 to EX14, wherein the mouthpiece element has a length of less than or equal to 16 millimetres. EX16: An aerosol-generating article according to any one of EX1 to EX15, wherein a ratio of the length of the mouthpiece element to the length of the hollow tubular element is at least 0.5.

[0271] EX17: An aerosol-generating article according to any one of EX1 to EX16, wherein a ratio of the length of the mouthpiece element to the length of the hollow tubular element is less than or equal to 1.2.

[0272] EX18: An aerosol-generating article according to any one of EX1 to EX17, wherein the hollow tubular element is longer than the mouthpiece element.

[0273] EX19: An aerosol-generating article according to any one of EX1 to EX18, wherein a ratio of the length of the mouthpiece element to the length of the rod of aerosol-generating substrate is at least 0.7.

[0274] EX20: An aerosol-generating article according to any one of EX1 to EX19, wherein a ratio of the length of the mouthpiece element to the length of the rod of aerosol-generating substrate is less than or equal to 2.

[0275] EX21: An aerosol-generating article according to any one of EX1 to EX20, wherein the mouthpiece element is longer than the rod of aerosol-generating article.

[0276] EX22: An aerosol-generating article according to any one of EX1 to EX21, wherein a ratio of the length of the mouthpiece element to the length of the aerosol-generating article is at least 0.18.

[0277] EX23: An aerosol-generating article according to any one of EX1 to EX22, wherein a ratio of the length of the mouthpiece element to the length of the aerosol-generating article is less than or equal to 0.4.

[0278] EX24: An aerosol-generating article according to any one of EX1 to EX23 further comprising a ventilation zone at a location along the hollow tubular element.

[0279] EX25: An aerosol-generating article according to EX24, wherein a distance between the ventilation zone and the downstream end of the aerosol-generating article is at least 12 millimetres.

[0280] EX26: An aerosol-generating article according to EX24 or EX25, wherein a distance between the ventilation zone and the downstream end of the aerosol-generating article is less than or equal to 24 millimetres.

[0281] EX27: An aerosol-generating article according to any one of EX24 to EX26, wherein a distance between the ventilation zone and the upstream end of the hollow tubular element is at least 6 millimetres.

[0282] EX28: An aerosol-generating article according to any one of EX24 to EX27, wherein a distance between the ventilation zone and the upstream end of the hollow tubular element is less than o equal to 16 millimetres. EX29: An aerosol-generating article according to any one of EX24 to EX28, wherein a distance between the ventilation zone and the downstream end of the hollow tubular element is at least 2 millimetres.

[0283] EX30: An aerosol-generating article according to any one of EX24 to EX29, wherein a distance between the ventilation zone and the downstream end of the hollow tubular element is less than or equal to 12 millimetres.

[0284] EX31: An aerosol-generating article according to any one of EX1 to EX30, wherein the aerosol-generating substrate comprises at least 5 percent by weight of aerosol former on a dry weight basis of the aerosol-generating substrate.

[0285] EX32: An aerosol-generating article according to any one of EX1 to EX31, wherein the aerosol-generating substrate comprises at least 40 percent by weight of aerosol former on a dry weight basis of the aerosol-generating substrate.

[0286] EX33: An aerosol-generating article according to any one of EX1 to EX32, wherein the aerosol-generating substrate comprises tobacco material, such as homogenised tobacco material.

[0287] EX34: An aerosol-generating article according to any one of EX1 to EX33, wherein the aerosol-generating substrate comprises non-tobacco plant material, such as cannabis material, ginger material, eucalyptus material, clove material, and star anise material.

[0288] EX35: An aerosol-generating article according to any one of EX1 to EX34 further comprising a susceptor located within the rod of aerosol-generating substrate.

[0289] EX36: An aerosol-generating article according to any one of EX1 to EX35, wherein the upstream element is in the form of a plug element.

[0290] EX37: An aerosol-generating article according to any one of EX1 to EX36, wherein the upstream element is made of or formed from cellulose acetate, paper or viscose; preferably paper or viscose.

[0291] EX38: An aerosol-generating article according to any one of EX1 to EX37, wherein a content of cellulose acetate in the upstream element is less than or equal to 15 percent by weight.

[0292] EX39: An aerosol-generating article according to any one of EX1 to EX38, wherein the upstream element has a length of at least 2 millimetres.

[0293] EX40: An aerosol-generating article according to any one of EX1 to EX39, wherein the upstream element has a length of less than or equal to 10 millimetres.

[0294] EX41: An aerosol-generating article according to any one of EX1 to EX40, wherein a ratio of the length of the mouthpiece element to the length of the upstream element is at least 1.8.

[0295] EX42: An aerosol-generating article according to any one of EX1 to EX41, wherein a ratio of the length of the mouthpiece element to the length of the upstream element is less than or equal to 4. EX43: An aerosol-generating article according to any one of EX1 to EX42, wherein a content of cellulose acetate in the mouthpiece element is less than or equal to 15 percent by weight.

[0296] EX44: An aerosol-generating article according to any one of EX1 to EX43, wherein the aerosol-generating article has an overall length of between about 40 millimetres and 50 millimetres.

[0297] EX45: An aerosol-generating article according to any one of EX1 to EX44, wherein the aerosol-generating article has an external diameter of between about 7 millimetres and about 8 millimetres.

[0298] EX46: An aerosol-generating article according to any one of EX1 to EX45 further comprising a tipping wrapper circumscribing the hollow tubular element and the mouthpiece element.

[0299] EX47: An aerosol-generating article according to EX46, wherein the tipping wrapper has a length of at least 14 millimetres.

[0300] EX48: An aerosol-generating article according to EX46 or EX47, wherein the tipping wrapper has a length of less than or equal to 30 millimetres.

[0301] EX49: An aerosol-generating article according to any one of EX1 to EX48, wherein the upstream element has a length of between 4 millimetres and 6 millimetres, wherein the rod of aerosol-generating substrate has a length of between 10 millimetres and 14 millimetres, wherein the hollow tubular element has a length of between 16 millimetres and 18 millimetres, and wherein the mouthpiece element has a length of between 10 millimetres and 14 millimetres.

[0302] EX50: An aerosol-generating article according to any one of EX1 to EX49, wherein the upstream element has a length of about 5 millimetres, the rod of aerosol-generating substrate has a length of about 11 millimetres, the hollow tubular element has a length of about 17 millimetres, and the mouthpiece element has a length of about 12 millimetres.

[0303] EX51: An aerosol-generating system comprising: an aerosol-generating article according to any one of EX1 to EX50, and an aerosol-generating device comprising a heating arrangement configured to heat at least a portion of the aerosol-generating substrate of the aerosol-generating article.

[0304] The present disclosure will be further described, by way of example only, with reference to the accompanying drawings, in which:

[0305] Figure 1 shows a schematic side sectional view of an aerosol-generating article in accordance with an example of the present disclosure;

[0306] Figure 2 shows a side sectional view of an aerosol-generating article in accordance with another example of the present disclosure;

[0307] Figure 3 shows a schematic side sectional view of an aerosol-generating system including the aerosol-generating article of Figure 1. Figure 1 shows an aerosol-generating article 10 comprising a rod of aerosol-generating substrate 12 and a downstream section 14 at a location downstream of the rod of aerosolgenerating substrate 12. Further, the aerosol-generating article 10 comprises an upstream section at a location upstream of the rod of aerosol-generating substrate 12.

[0308] The aerosol-generating article 10 extends from an upstream or distal end 16 to a downstream or proximal end 18. The downstream section 14 extends from the downstream end of the rod of aerosol-generating substrate 12 to the downstream end 18 of the aerosol-generating article 10. The upstream section extends from the upstream end 16 of the aerosol-generating article 10 to the upstream end of the rod of aerosol-generating substrate 12.

[0309] The aerosol-generating article has an overall length of about 45 millimetres and an external diameter of about 7.2 millimetres.

[0310] The aerosol-generating substrate in the rod of aerosol-generating substrate 12 is in the form of a gathered sheet of homogenised tobacco material. The rod of aerosol-generating substrate 12 has a length of about 11 millimetres and an external diameter of about 7.1 millimetres.

[0311] The aerosol-generating article 10 further comprises a susceptor 60. The susceptor 60 is positioned within the rod of aerosol-generating substrate 12 and extends all the way from the upstream end to the downstream end of the rod of aerosol-generating substrate 12. In effect, the susceptor 60 has substantially the same length as the rod of aerosol-generating substrate 12.

[0312] The susceptor 60 is provided in the form of a strip and has a length of about 11 millimetres, a thickness of about 60 micrometres, and a width of about 4 millimetres.

[0313] The downstream section 14 comprises a hollow tubular element 20 and a mouthpiece element 50 located downstream of the hollow tubular element 20.

[0314] The hollow tubular element 20 is in longitudinal alignment with the rod of aerosolgenerating substrate 12 and extends from the downstream end of the rod of aerosol-generating substrate 12 to the upstream end of the mouthpiece element 50. The hollow tubular element 20 abuts the downstream end of the rod of aerosol-generating substrate 12 to the upstream end of the mouthpiece element 50.

[0315] The hollow tubular element 20 is provided in the form of a hollow cylindrical tube and defines a hollow section of the aerosol-generating article 10. The hollow tubular element 20 defines an internal cavity 22 that extends all the way from the upstream end of the hollow tubular element 20 to the downstream end of the hollow tubular element. The internal diameter of the hollow tubular element 20 is substantially constant along the entire length of the aerosolgenerating article. Accordingly, the internal cavity 22 has a substantially constant diameter along the entire length of the internal cavity 22.

[0316] The internal cavity 22 is substantially empty, and so substantially unrestricted airflow is enabled along the internal cavity 22. The hollow tubular element 20 does not substantially contribute to the overall resistance to draw of the aerosol-generating article 10. In more detail, the resistance to draw of the hollow tubular element 20 is about 0 mm H2O.

[0317] The hollow tubular element 20 has a length of about 17 millimetres, an external diameter of about 7.0 millimetres, and a wall thickness of about 240 micrometres.

[0318] The hollow tubular element 20 is formed from cardboard.

[0319] The aerosol-generating article 10 comprises a ventilation zone 30 provided at a location along the hollow tubular element 20. In more detail, the ventilation zone 30 is provided at about 18 millimetres from the downstream end 18 of the article 10. The ventilation zone 30 is provided at about 6 millimetres upstream from the downstream end of the hollow tubular element 20 and about 11 millimetres downstream from the upstream end of the hollow tubular element 20. The ventilation zone 30 comprises a circumferential row of openings or perforations circumscribing the hollow tubular element 20. The perforations of the ventilation zone 30 extend through the wall of the hollow tubular element 20 in order to allow fluid ingress into the internal cavity 22 from the exterior of the article 10. The circumferential row of openings or perforations has nine slits.

[0320] The mouthpiece element 50 is in longitudinal alignment with the hollow tubular element 20 and abuts the downstream end of the hollow tubular element 20. In particular, the mouthpiece element 50 extends from the downstream end of the hollow tubular element 20 to the downstream end 18 of the aerosol-generating article 10.

[0321] The mouthpiece element 50 has a length of about 12 millimetres and an external diameter of about 7.2 millimetres.

[0322] The aerosol-generating article also comprises a tipping wrapper 52 circumscribing the hollow tubular element 20 along a portion of the length of the hollow tubular element 20 and the mouthpiece element 50 along the entire length of the mouthpiece element 50. This way the tipping wrapper 52 joins the mouthpiece element 50 to the hollow tubular element 20. The tipping wrapper 52 extends from the downstream end of the mouthpiece element 50 (which corresponds to the downstream end 18 of the aerosol-generating article 10) to a location along the hollow tubular element 20.

[0323] The tipping wrapper 52 has a length of about 20 millimetres.

[0324] Additionally, the ventilation zone 30 may comprise a circumferential row of perforations provided on the tipping wrapper 52. The perforations of the tipping wrapper 52 overlap the perforations provided on the hollow tubular element 20. Accordingly, the tipping wrapper 52 overlies the perforations of the ventilation zone 30 provided on the hollow tubular element 20.

[0325] The upstream section comprises an upstream element 42. The upstream element 42 is in longitudinal alignment with the rod of aerosol-generating substrate 12 and abuts the upstream end of the rod of aerosol-generating substrate 12. In particular, the upstream element 42 extends from the upstream end 16 of the aerosol-generating article 10 to the upstream end of the rod of aerosol-generating substrate 12. The upstream element 42 is in the form of a solid plug. The upstream element 42 may comprise a crimped or convoluted sheet of paper. The upstream element has a length of about 5 millimetres and an external diameter of about 7.1 millimetres.

[0326] In another example (not shown), the aerosol-generating article is substantially similar to the aerosol-generating article 10 shown in Figure 1, but with the following differences: the aerosolgenerating article has an external diameter of about 7.18 millimetres, the upstream element has an external diameter of about 7.05 millimetres, the rod of aerosol-generating substrate has an external diameter of about 7.05 millimetres, and the mouthpiece element has an external diameter of about 7.15 millimetres.

[0327] Figure 2 shows an aerosol-generating article 11 in accordance with another example of the present disclosure.

[0328] The aerosol-generating article 11 shown in Figure 2 is substantially similar to the aerosolgenerating article 10 shown in Figure 1 and the same reference numerals are used to designate like parts.

[0329] The aerosol-generating article 11 shown in Figure 2 differs from the aerosol-generating article 10 shown in Figure 1 in that the upstream element 44 of the aerosol-generating article 11 is in the form of a tube rather than a solid plug.

[0330] Figure 3 shows an aerosol-generating system 200 comprising the aerosol-generating article 10 shown in Figure 1 and an aerosol-generating device 250. The aerosol-generating device 250 comprises a housing (or body) 201, extending between a downstream end and an upstream end. The housing 201 defines a heating chamber 202 for receiving an aerosol-generating article 10. The heating chamber 202 is defined by a closed, upstream end and an open, downstream end. The downstream end of the heating chamber 202 is located at the downstream end of the aerosol-generating device 250. The aerosol-generating article 10 is configured to be received through the open, downstream end of the heating chamber 202 and is configured to abut a closed, upstream end of the heating chamber 202, when the aerosol-generating article 10 is fully received in the heating chamber 202.

[0331] The aerosol-generating device 250 further comprises a heater arrangement 203 and a power source 204 for supplying power to the heater arrangement 203. A controller (not shown) is also provided to control such supply of power to the heater arrangement 203. The heater arrangement 203 is configured to controllably heat the aerosol-generating article 10 during use, when the aerosol-generating article 10 is fully received within the heating chamber 202.

[0332] The heater arrangement 203 extends from an upstream end to a downstream end defining a heating zone. The heater arrangement 203 is substantially the same length as the rod of aerosol-generating substrate 12 such that when the aerosol-generating article 10 is received within the heating chamber 202, the entire length of the rod of aerosol-generating substrate 12 is received within the heating zone to provide optimal heating of the rod of aerosol-generating substrate 12.

[0333] The ventilation zone 30 of the aerosol-generating article 10 is arranged to be exposed when the aerosol-generating article 10 is received within the heating chamber 202 of the aerosolgenerating device 250.

[0334] The heater arrangement 203 comprises an induction element. In use, the aerosolgenerating article 10 is received within the heating chamber 202 of the aerosol-generating device 250. The heater arrangement 203 is activated by the controller and the induction element cooperates, as described previously, with the susceptor 60 in the aerosol-generating article 10 to generate heat which is transferred directly to the aerosol-generating substrate which is thermally coupled with the susceptor 60. This causes aerosol species to be released from the aerosolgenerating substrate.

[0335] When a pressure drop is applied to the downstream end 18 of the aerosol-generating article 10, air is drawn into the heating chamber 202 via an air inlet 212 of the aerosol-generating device 250 and into the rod of aerosol-generating substrate 12 of the aerosol-generating article 10. The aerosol species released upon heating are entrained in the airflow which then passes through the downstream section 14 of the aerosol-generating article 10 before leaving through the downstream end 18 of the aerosol-generating article 10.

[0336] The specific embodiments and examples described above illustrate, but do not limit, the invention. It is to be understood that other embodiments of the invention may be made and the specific embodiments and examples described herein are not exhaustive.

[0337] For the purpose of the present description and of the appended claims, except where otherwise indicated, all numbers expressing amounts, quantities, percentages, and so forth, are to be understood as being modified in all instances by the term "about". Also, all ranges include the maximum and minimum points disclosed and include any intermediate ranges therein, which may or may not be specifically enumerated herein. In this context, therefore, a number A is understood as A ± 5% of A. Within this context, a number A may be considered to include numerical values that are within general standard error for the measurement of the property that the number A modifies. The number A, in some instances as used in the appended claims, may deviate by the percentages enumerated above provided that the amount by which A deviates does not materially affect the basic and novel characteristic(s) of the claimed invention. Also, all ranges include the maximum and minimum points disclosed and include any intermediate ranges therein, which may or may not be specifically enumerated herein.

Claims

CLAIMS:

1. An aerosol-generating article for producing an inhalable aerosol upon heating, the aerosol-generating article comprising:a rod of aerosol-generating substrate;a susceptor arranged within the rod of aerosol-generating substrate;an upstream element located upstream of the rod of aerosol-generating substrate and abutting the upstream end of the rod of aerosol-generating substrate; anda downstream section arranged downstream of the rod of aerosol-generating substrate, the downstream section comprising:a hollow tubular element abutting the downstream end of the rod of aerosolgenerating substrate; anda mouthpiece element located downstream of the hollow tubular element and abutting the downstream end of the hollow tubular element,wherein a ratio of the length of the mouthpiece element to the length of the hollow tubular element is at least 0.5.

2. An aerosol-generating article according to claim 1, wherein the upstream element has a length of between 4 millimetres and 6 millimetres, wherein the rod of aerosol-generating substrate has a length of between 10 millimetres and 14 millimetres, wherein the hollow tubular element has a length of between 16 millimetres and 18 millimetres, and wherein the mouthpiece element has a length of between 10 millimetres and 14 millimetres.

3. An aerosol-generating article according to claim 1, wherein the hollow tubular element is longer than the mouthpiece element.

4. An aerosol-generating article according to any one of the preceding claims, wherein the hollow tubular element has a substantially constant internal diameter along the entire length of the hollow tubular element.

5. An aerosol-generating article according to any one of the preceding claims, wherein the upstream element is an upstream plug element.

6. An aerosol-generating article according to any one of the preceding claims, wherein a ratio between the wall thickness of the hollow tubular element and the internal diameter of the hollow tubular element is less than or equal to 0.1.

7. An aerosol-generating article according to any one of the preceding claims further comprising a ventilation zone at a location along the hollow tubular element, and wherein a distance between the ventilation zone and the upstream end of the hollow tubular element is at least 8 millimetres.

8. An aerosol-generating article according to claim 7, wherein a distance between the ventilation zone and the downstream end of the hollow tubular element is less than or equal to 8 millimetres.

9. An aerosol-generating article according to any one of the preceding claims, wherein a ratio of the length of the mouthpiece element to the length of the aerosol-generating substrate is at least 0.7.

10. An aerosol-generating article according to any one of the preceding claims, wherein the mouthpiece element is longer than the rod of aerosol-generating substrate.

11. An aerosol-generating article according to any one of the preceding claim, wherein a ratio of the length of the mouthpiece element to the length of the aerosol-generating article is at least 0.2.

12. An aerosol-generating article according to any one of the preceding claims, wherein a ratio of the length of the mouthpiece element to the length of the upstream element is at least 1.8.

13. An aerosol-generating article according to any one of the preceding claims, wherein a ratio of the length of the rod of aerosol-generating substrate to the length of the hollow tubular element is at least 0.6.

14. An aerosol-generating article according to any one of the preceding claims, wherein a ratio of the length of the hollow tubular element to the length of the aerosol-generating article is less than or equal to 0.4.

15. An aerosol-generating article according to any one of the preceding claims, wherein the aerosol-generating article has an overall length of less than or equal to 50 millimetres.

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