Aerosol-generating article having grooved air channeling elements - Patents.com

Abstract

An aerosol-generating article is provided for generating an inhalable aerosol upon heating. The aerosol-generating article comprises a rod of an aerosol-generating substrate. The aerosol-generating article comprises an air channeling element abutting the rod of the aerosol-generating substrate. The air channeling element comprises a groove defined on an outer surface. The groove defines an external air passageway extending from an upstream end of the air channeling element to a downstream end of the air channeling element. An aerosol generation system is also provided comprising the aerosol-generating article and an aerosol generating device including an external heater configured to receive and externally heat the aerosol-generating article.

Description

[Technical field]

[0001] The present disclosure relates to an aerosol-generating article comprising an aerosol-generating substrate and adapted to generate an inhalable aerosol upon heating. The present disclosure also relates to an aerosol-generating system comprising such an aerosol-generating article. [Background technology]

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

[0003] Numerous prior art documents disclose aerosol generating devices for consuming aerosol-generating articles. Such devices include, for example, electrically heated aerosol generating devices, in which the aerosol is generated by heat transfer from one or more electric heater elements of the aerosol generating device to an aerosol-generating substrate of the heated aerosol-generating article. For example, electrically heated aerosol generating devices have been proposed, which comprise an internal heater blade adapted to be inserted into the aerosol-generating substrate. The use of aerosol-generating articles in combination with external heating systems is also known. For example, WO 2020 / 115151 describes the provision of one or more heating elements arranged around the periphery of the aerosol-generating article when the aerosol-generating article is received in a cavity of the aerosol-generating device. Alternatively, an inductively heatable aerosol-generating article is proposed by WO 2015 / 176898, which comprises an aerosol-generating substrate and a susceptor disposed within the aerosol-generating substrate. Summary of the Invention [Problem to be solved by the invention]

[0004] Aerosol-generating articles in which the tobacco-containing substrate is heated rather than combusted present a number of challenges not found in conventional smoking articles. First, the tobacco-containing substrate is typically heated to a significantly lower temperature compared to the temperature reached by the combustion front of a conventional cigarette. This can affect the nicotine release from the tobacco-containing substrate and the nicotine delivery to the consumer. At the same time, if the heating temperature is increased in an attempt to enhance nicotine delivery, the aerosol generated typically needs to be cooled more extensively and more quickly before reaching the consumer. However, technical solutions commonly used to cool mainstream smoke in conventional smoking articles, such as providing a high filtration efficiency segment at the mouth end of the cigarette, can have undesirable effects in aerosol-generating articles in which the tobacco-containing substrate is heated rather than combusted, as this can reduce nicotine delivery. As a result, it would be desirable to provide a novel aerosol-generating article that can consistently and reliably deliver aerosol to consumers quickly and satisfactorily.

[0005] Second, there is a generally felt need for aerosol-generating articles that are easy to use and have improved practicality. For example, it would be desirable to provide an aerosol-generating article that can be easily inserted into the heating cavity of an aerosol generating device and at the same time be securely held within the heating cavity so that it does not slip out during use.

[0006] It would therefore be desirable to provide new and improved aerosol-generating articles adapted to achieve at least one of the above desired results, and further to provide one such aerosol-generating article that can be efficiently and rapidly manufactured, and that preferably has a satisfactory RTD and low article-to-article RTD variation. [Brief description of the drawings]

[0007] [Figure 1a] 1 shows a schematic side perspective exploded view of an aerosol-generating article according to one embodiment of the present invention. [Figure 1b] FIG. 1b shows a schematic side perspective view of the assembled aerosol-generating article shown in FIG. [Diagram 2] 1 shows a schematic side perspective view of an aerosol-generating article according to one embodiment of the present invention. [Diagram 3] 1 shows a schematic side perspective view of an aerosol-generating article according to one embodiment of the present invention. [Figure 4] 1 shows a schematic side perspective view of an aerosol-generating article according to one embodiment of the present invention. [Figure 5a] FIG. 2 shows a cross-sectional view of an air channeling element of an aerosol-generating article according to one embodiment of the present invention. [Figure 5b] FIG. 2 shows a cross-sectional view of an air channeling element of an aerosol-generating article according to one embodiment of the present invention. [Figure 6a] FIG. 2 shows a cross-sectional view of an air channeling element of an aerosol-generating article according to one embodiment of the present invention. [Figure 6b] FIG. 2 shows a cross-sectional view of an air channeling element of an aerosol-generating article according to one embodiment of the present invention. [Figure 7a] 1 shows a side cross-sectional view of an aerosol generation system according to the present disclosure. [Figure 7b] 7a shows a partial cross-sectional view of an air channeling element of an aerosol-generating article taken along line AA shown in FIG. 7a. [Figure 7c] A cross-sectional view of the air channeling element of the aerosol-generating article is shown along line AA in FIG. 7a. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] The present disclosure relates to an aerosol-generating article. The aerosol-generating article may comprise a rod of an aerosol-generating substrate. The aerosol-generating article may comprise an air channeling element abutting the rod of the aerosol-generating substrate. The aerosol-generating article may comprise an air channeling element upstream or downstream of the rod of the aerosol-generating substrate. The aerosol-generating article may comprise an air channeling element both upstream and downstream of the rod of the aerosol-generating substrate. The or each air channeling element may abut the rod of the aerosol-generating substrate. The or each air channeling element may comprise a groove defined on an outer surface. The groove may define an outer air passageway extending from an upstream end of the air channeling element to a downstream end of the air channeling element.

[0009] The present disclosure relates to an aerosol-generating article. The aerosol-generating article may comprise a rod of an aerosol-generating substrate. The aerosol-generating article may comprise a downstream section extending downstream of the rod of the aerosol-generating substrate. The downstream section may comprise an air channeling element. The downstream air channeling element may abut the rod of the aerosol-generating substrate. The downstream air channeling element may comprise a groove defined on an outer surface. The groove may define an outer air passageway extending from an upstream end of the air channeling element to a downstream end of the air channeling element.

[0010] The present disclosure relates to an aerosol-generating article. The aerosol-generating article may comprise a rod of an aerosol-generating substrate. The aerosol-generating article may comprise an upstream section extending upstream of the rod of the aerosol-generating substrate. The upstream section may comprise an air channeling element. The upstream air channeling element may abut the rod of the aerosol-generating substrate. The upstream air channeling element may comprise a groove defined on an outer surface. The groove may define an outer air passageway extending from an upstream end of the air channeling element to a downstream end of the air channeling element.

[0011] The present invention relates to an aerosol-generating article. The aerosol-generating article comprises a rod of an aerosol-generating substrate. The aerosol-generating article comprises an air channeling element abutting the rod of the aerosol-generating substrate. The air channeling element may be located upstream or downstream of the rod of the aerosol-generating substrate. The aerosol-generating article may comprise an air channeling element both upstream and downstream of the rod of the aerosol-generating substrate. The air channeling element comprises a groove defined on an outer surface. The groove defines an outer air passageway extending from an upstream end of the air channeling element to a downstream end of the air channeling element.

[0012] The present disclosure further relates to an aerosol generating system comprising the aerosol generating article and aerosol generating device described above, the aerosol generating device comprising a heating chamber for receiving the aerosol generating article and a heating member disposed in or around the periphery of the heating chamber.

[0013] The aerosol-generating article according to the present disclosure provides an improved configuration that has a direct impact on facilitating the rate and efficiency of aerosol generation, especially when the aerosol-generating article is heated externally. The rate of aerosol generation refers to how fast an aerosol can be generated. This results from providing an air channeling element with external grooves upstream or downstream of the aerosol-generating substrate. The external grooves of the air channeling element can facilitate air flow through the peripheral portion of the aerosol-generating substrate. With external heating, the peripheral layer of the substrate may be heated first and thus may be the first portion of the substrate that is the source of aerosol generation during the initial stage of the heating cycle of the article. By aligning the grooves and the resulting external air flow with such peripheral portion of the substrate, air drawn towards or from the aerosol-generating substrate may be directed towards or drawn from such peripheral layer of the substrate.

[0014] An upstream air channeling element located upstream of the aerosol-generating substrate advantageously focuses air entrainment to the peripheral portions of the substrate, as described above, while also providing a barrier against inadvertent expulsion of debris of substrate material through the upstream end of the aerosol-generating article during consumption and transport.

[0015] A downstream air channeling element located downstream of the aerosol-generating substrate advantageously promotes air entrainment flow through the peripheral portion of the substrate. The downstream air channeling element further enhances cooling due to the proximity of the grooves to the exterior or periphery of the aerosol-generating article, thereby allowing heat transfer to the exterior of the aerosol-generating article in addition to the material of the air channeling element itself. Thus, the present invention promotes rapid aerosol nucleation and aerosol delivery to the user, particularly during the initial stages of consumption of an externally heated article.

[0016] As used herein, the term "length" means the dimension along the longitudinal axis of a component, device, or article from the most upstream or distal point of the component to the most downstream or proximal point of the component.

[0017] As used herein, the term "longitudinal" refers to a direction corresponding to the major longitudinal axis of a component, device, or article that extends between opposing upstream and downstream ends of the component, device, or article. The term "transverse" is used to describe a direction perpendicular to the longitudinal axis. As used herein, the term "cross section" (or alternatively, a "transverse cross section") may be used to describe a cross section of a component, device, or article perpendicular to the longitudinal axis.

[0018] As used herein, the terms "upstream" and "downstream" describe the relative location of an element or portion of an element of a component, device, article with respect to the direction in which air may be drawn through the component, device, or article during use. During use or consumption, air may be drawn through the aerosol-generating article in a longitudinal direction.

[0019] As mentioned above, the aerosol-generating article according to the invention comprises a rod of an aerosol-generating substrate. Furthermore, the aerosol-generating article according to the invention comprises one or more elements arranged downstream of the aerosol-generating substrate. The one or more elements downstream of the rod of the aerosol-generating substrate form a downstream section of the aerosol-generating substrate. Furthermore, the aerosol-generating article according to the invention comprises an element arranged upstream of the aerosol-generating substrate. The element upstream of the rod of the aerosol-generating substrate defines an upstream section of the aerosol-generating article.

[0020] The rod of aerosol-generating substrate is preferably surrounded by a wrapper, such as plug wrap.

[0021] Preferably, the rod of the aerosol-generating substrate has a length of at least about 8 millimeters. Preferably, the rod of the aerosol-generating substrate has a length of at least about 9 millimeters. More preferably, the rod of the aerosol-generating substrate has a length of at least about 10 millimeters.

[0022] For example, the rod of the aerosol-generating substrate preferably has a length of from about 8 mm to about 16 mm, or from about 9 mm to about 15 mm, or from about 10 mm to about 14 mm. The rod of the aerosol-generating substrate may have a length of about 12 mm.

[0023] The ratio of the length of the rod of the aerosol-generating substrate to the overall length of the aerosol-generating article is preferably at least about 0.15, more preferably at least about 0.2, and most preferably at least about 0.22.

[0024] The ratio of the length of the rod of the aerosol-generating substrate to the overall length of the aerosol-generating article is preferably not greater than 0.35, more preferably not greater than about 0.33, more preferably not greater than about 0.3.

[0025] The ratio between the length of the aerosol-generating substrate rod and the overall length of the aerosol-generating article is preferably approximately 0.25.

[0026] The rod of aerosol-generating substrate preferably has an outer diameter approximately equal to the outer diameter of the aerosol-generating article.

[0027] The "outer diameter of the aerosol-generating substrate rod" may be calculated as the average of multiple measurements of the diameter of the aerosol-generating substrate rod taken at different locations along the length of the aerosol-generating substrate rod.

[0028] Preferably, the aerosol-generating substrate rod has an outer diameter of at least about 5 millimeters. More preferably, the aerosol-generating substrate rod has an outer diameter of at least about 6 millimeters. Even more preferably, the aerosol-generating substrate rod has an outer diameter of at least about 7 millimeters.

[0029] Preferably, the aerosol-generating substrate rod has an outer diameter of about 12 millimeters or less. More preferably, the aerosol-generating substrate rod has an outer diameter of about 10 millimeters or less. Even more preferably, the aerosol-generating substrate rod has an outer diameter of about 8 millimeters or less.

[0030] In general, it has been observed that the smaller the diameter of the rod of the aerosol-generating substrate, the lower the temperature required to raise the core temperature of the rod of the aerosol-generating substrate so that a sufficient amount of vaporizable species is released from the aerosol-generating substrate to form a desired amount of aerosol. At the same time, without wishing to be bound by theory, it is understood that the smaller the diameter of the rod of the aerosol-generating substrate, the faster the heat provided to the aerosol-generating article can penetrate the entire volume of the aerosol-generating substrate. Nevertheless, if the diameter of the rod of the aerosol-generating substrate is too small, the volume-to-surface area ratio of the aerosol-generating substrate becomes unfavorable as the amount of available aerosol-generating substrate decreases.

[0031] The diameter of the rod of the aerosol-generating substrate falling within the range described herein is particularly advantageous in terms of the balance between energy consumption and aerosol delivery. This advantage is particularly realized when an aerosol-generating article comprising a rod of the aerosol-generating substrate having the diameter described herein is used in combination with an external heater arranged around the periphery of the aerosol-generating article. It has been observed that under such operating conditions, less thermal energy is required to achieve a sufficiently high temperature at the core of the rod of the aerosol-generating substrate, and generally at the core of the article. Thus, when operating at a lower temperature, the desired target temperature at the core of the aerosol-generating substrate may be achieved within a desirably reduced time frame and with less energy consumption.

[0032] The rod of the aerosol-generating substrate may have an outer diameter of about 5 mm to about 12 mm, preferably about 6 mm to about 12 mm, more preferably about 7 mm to about 12 mm. The rod of the aerosol-generating substrate may have an outer diameter of about 5 mm to about 10 mm, preferably about 6 mm to about 10 mm, more preferably about 7 mm to about 10 mm. The rod of the aerosol-generating substrate has an outer diameter of about 5 mm to about 8 mm, preferably about 6 mm to about 8 mm, more preferably about 7 mm to about 8 mm.

[0033] The aerosol-generating substrate rod preferably has an outer diameter of less than about 7.5 millimeters.By way of example, the aerosol-generating substrate rod may have an outer diameter of about 7.2 millimeters.

[0034] The rod of aerosol-generating substrate preferably has a substantially uniform cross-section along the length of the rod, and it is particularly preferred that the rod of aerosol-generating substrate has a substantially circular cross-section.

[0035] In an aerosol-generating article according to the invention, the ratio between the length of the rod of the aerosol-generating substrate and the total length of the aerosol-generating article may be about 0.60 or less. Preferably, the ratio between the length of the rod of the aerosol-generating substrate and the total length of the aerosol-generating article may be about 0.50 or less. More preferably, the ratio between the length of the rod of the aerosol-generating substrate and the total length of the aerosol-generating article may be about 0.40 or less. Even more preferably, the ratio between the length of the rod of the aerosol-generating substrate and the total length of the aerosol-generating article may be about 0.30 or less.

[0036] In an aerosol-generating article according to the invention, the ratio between the length of the rod of the aerosol-generating substrate and the overall length of the aerosol-generating article may be at least about 0.10. Preferably, the ratio between the length of the rod of the aerosol-generating substrate and the overall length of the aerosol-generating article may be at least about 0.15. More preferably, the ratio between the length of the rod of the aerosol-generating substrate and the overall length of the aerosol-generating article may be at least about 0.20. Preferably, the ratio between the length of the rod of the aerosol-generating substrate and the overall length of the aerosol-generating article may be at least about 0.25.

[0037] The ratio between the length of the rod of the aerosol-generating substrate and the total length of the aerosol-generating article may be about 0.10 to about 0.60, preferably about 0.15 to about 0.60, more preferably about 0.20 to about 0.60, and even more preferably about 0.25 to about 0.60. The ratio between the length of the rod of the aerosol-generating substrate and the total length of the aerosol-generating article may be about 0.10 to about 0.50, preferably about 0.15 to about 0.50, more preferably about 0.20 to about 0.50, and even more preferably about 0.25 to about 0.50. The ratio between the length of the rod of the aerosol-generating substrate and the total length of the aerosol-generating article may be about 0.10 to about 0.40, preferably about 0.15 to about 0.40, more preferably about 0.20 to about 0.40, and even more preferably about 0.25 to about 0.40. By way of example, the ratio between the length of the rod of the aerosol-generating substrate and the overall length of the aerosol-generating article may be from about 0.25 to about 0.30, preferably about 0.27.

[0038] It is preferred that the density of the aerosol-generating substrate is at least about 150 mg per cubic centimeter. More preferably, the density of the aerosol-generating substrate is at least about 175 mg per cubic centimeter. More preferably, the density of the aerosol-generating substrate is at least about 200 mg per cubic centimeter. Even more preferably, the density of the aerosol-generating substrate is at least about 250 mg per cubic centimeter.

[0039] Preferably, the density of the aerosol-generating substrate is about 500 mg per cubic centimeter or less. More preferably, the density of the aerosol-generating substrate is about 450 mg per cubic centimeter or less. More preferably, the density of the aerosol-generating substrate is about 400 mg per cubic centimeter or less. Even more preferably, the density of the aerosol-generating substrate is about 350 mg per cubic centimeter or less.

[0040] For example, the density of the aerosol-generating substrate is preferably about 150 mg per cubic centimeter to about 500 mg per cubic centimeter, preferably about 175 mg per cubic centimeter to about 450 mg per cubic centimeter, more preferably about 200 mg per cubic centimeter to about 400 mg per cubic centimeter, and even more preferably about 250 mg per cubic centimeter to about 350 mg per cubic centimeter. The density of the aerosol-generating substrate is preferably about 300 mg per cubic centimeter.

[0041] The aerosol-generating substrate rod preferably comprises cut tobacco material (e.g., tobacco cut filler) and has a density of from about 150 mg per cubic centimeter to about 500 mg per cubic centimeter, preferably from about 175 mg per cubic centimeter to about 450 mg per cubic centimeter, more preferably from about 200 mg per cubic centimeter to about 400 mg per cubic centimeter, more preferably from about 250 mg per cubic centimeter to about 350 mg per cubic centimeter, and most preferably about 300 mg per cubic centimeter.

[0042] Preferably, the RTD of the rod of the aerosol-generating substrate is about 10 millimeters H2O or less. More preferably, the RTD of the rod of the aerosol-generating substrate is about 9 millimeters H2O or less. Even more preferably, the RTD of the rod of the aerosol-generating substrate is about 8 millimeters H2O or less.

[0043] Preferably, the RTD of the rod of the aerosol-generating substrate is at least about 4 millimeters HO. More preferably, the RTD of the rod of the aerosol-generating substrate is at least about 5 millimeters HO. Even more preferably, the RTD of the rod of the aerosol-generating substrate is at least about 6 millimeters HO.

[0044] The RTD of the rod of the aerosol-generating substrate may be about 4 mmH2O to about 10 mmH2O, preferably about 5 mmH2O to about 10 mmH2O, preferably about 6 mmH2O to about 25 mmH2O. The RTD of the rod of the aerosol-generating substrate may be about 4 mmH2O to about 20 mmH2O, preferably about 5 mmH2O to about 18 mmH2O, preferably about 6 mmH2O to about 16 mmH2O. The RTD of the rod of the aerosol-generating substrate may be about 4 mmH2O to about 15 mmH2O, preferably about 5 mmH2O to about 14 mmH2O, more preferably about 6 mmH2O to about 12 mmH2O.

[0045] The aerosol-generating substrate may be a solid aerosol-generating substrate. The aerosol-generating substrate preferably comprises an aerosol former. The aerosol former may be any suitable known compound or mixture of compounds that promotes the formation of a dense and stable aerosol during use. The aerosol former may promote the aerosol to be substantially resistant to thermal decomposition at temperatures typically encountered during use of the aerosol-generating article. Suitable aerosol formers are, for example, polyhydric alcohols (e.g., triethylene glycol, 1,3-butanediol, propylene glycol, glycerin, etc.), esters of polyhydric alcohols (e.g., glycerol mono-, di-, or triacetate, etc.), aliphatic esters of mono-, di-, or polycarboxylic acids (e.g., dimethyl dodecanedioate, dimethyl tetradecanedioate, etc.), and combinations thereof.

[0046] The aerosol former preferably comprises one or more of glycerin and propylene glycol. The aerosol former may consist of glycerin, or propylene glycol, or a combination of glycerin and propylene glycol.

[0047] Preferably, the aerosol-generating substrate comprises at least 5 percent by weight of aerosol formers based on the dry weight of the aerosol-generating substrate. In other words, the aerosol-generating substrate has an aerosol former content of at least 5 percent by dry weight. The aerosol-generating substrate may comprise at least 7 percent by weight of aerosol formers based on the dry weight of the aerosol-generating substrate. The aerosol-generating substrate may comprise at least 10 percent by weight of aerosol formers based on the dry weight of the aerosol-generating substrate. The aerosol-generating substrate may comprise at least 12 percent by weight of aerosol formers based on the dry weight of the aerosol-generating substrate. The aerosol-generating substrate may comprise at least 13 percent by weight of aerosol formers based on the dry weight of the aerosol-generating substrate.

[0048] The aerosol-generating substrate may comprise up to 22 percent by weight of the aerosol former, based on the dry weight of the aerosol-generating substrate.The aerosol-generating substrate may comprise up to 19 percent by weight of the aerosol former, based on the dry weight of the aerosol-generating substrate.The aerosol-generating substrate may comprise up to 16 percent by weight of the aerosol former, based on the dry weight of the aerosol-generating substrate.

[0049] The aerosol-generating substrate may comprise an amount of aerosol former of from 10 weight percent to 22 weight percent based on the dry weight of the aerosol-generating substrate, more preferably from 12 weight percent to 19 weight percent based on the dry weight of the aerosol-generating substrate, most typically from 13 weight percent to 16 weight percent based on the dry weight of the aerosol-generating substrate.

[0050] The aerosol-generating substrate may comprise cut tobacco material. For example, the cut tobacco material may be in the form of cut filler. The cut tobacco material may be in the form of a cut sheet of homogenized tobacco material.

[0051] In the context of this specification, the term "cut filler" is used to describe a blend of finely chopped plant material, such as tobacco plant material, specifically including one or more of leaf blades, processed stems and veins, and homogenized plant material.

[0052] Preferably, the amount of the aerosol former is at least 5 weight percent based on the dry weight of the cut filler, preferably 10 weight percent to 22 weight percent based on the dry weight of the cut filler, more preferably the amount of the aerosol former is 12 weight percent to 19 weight percent based on the dry weight of the cut filler, for example, the amount of the aerosol former is 13 weight percent to 16 weight percent based on the dry weight of the cut filler. When the aerosol former is added to the cut filler in the above-mentioned amount, the cut filler can become relatively sticky. This advantageously helps to hold the cut filler in place within the article, since the particles of the cut filler tend to adhere not only to the surrounding cut filler particles, but also to surrounding surfaces (e.g., the inner surface of the wrapper surrounding the cut filler).

[0053] The amount of aerosol former may have a target value of about 13 or 18 weight percent based on the dry weight of the cut filler. The most efficient amount of aerosol former also depends on the cut filler and whether the cut filler contains plant lamina or homogenized plant material. For example, the type of cut filler, among other factors, determines the extent to which the aerosol former can facilitate the release of material from the cut filler.

[0054] For these reasons, a rod of aerosol-generating substrate comprising cut fillers as described above has the ability to efficiently generate sufficient aerosol at relatively low temperatures: a temperature of 150°C to 200°C in a heating chamber may be sufficient for one such cut filler to generate sufficient aerosol, whereas a temperature of about 250°C is typically employed in aerosol generating devices using tobacco cast leaf sheets.

[0055] A further advantage associated with operating at lower temperatures is that the need for cooling the aerosol is reduced: since lower temperatures are generally used, simpler cooling mechanisms may be sufficient, which in turn allows for the use of simpler and less complex structures for the aerosol-generating article.

[0056] The aerosol-generating substrate may comprise homogenized plant material, preferably homogenized tobacco material.

[0057] As used herein, the term "homogenized plant material" encompasses any plant material formed by agglomeration of plant particles. For example, a sheet or web of homogenized tobacco material for an aerosol-generating substrate of the present invention may be formed by agglomerating particles of tobacco material obtained by grinding, crushing, or comminuting plant material and, optionally, one or more of tobacco lamina and tobacco stems. Homogenized plant material may be produced by casting, extrusion, a papermaking process, or any other suitable process known in the art.

[0058] The homogenized plant material can be provided in any suitable form.

[0059] For example, the homogenized plant material may be in the form of one or more sheets. As used herein in connection with the present invention, the term "sheet" describes a laminar element having a width and length that substantially exceeds its thickness.

[0060] The homogenized plant material may be in the form of a plurality of pellets or granules.

[0061] The homogenized plant material may be in the form of multiple strands, strips, or pieces. As used herein, the term "strand" describes an elongated element of material having a length substantially greater than its width and thickness. The term "strand" should be considered to encompass strips, pieces, and any other homogenized plant material having a similar morphology. Strands of homogenized plant material may be formed from a sheet of homogenized plant material, for example, by cutting or chopping, or by other methods, such as extrusion methods.

[0062] The strands may be formed in situ within the aerosol-generating substrate as a result of splitting or cracking of the sheet of homogenized plant material during formation of the aerosol-generating substrate, for example as a result of crimping. The strands of homogenized plant material within the aerosol-generating substrate may be separated from one another. Each strand of homogenized plant material within the aerosol-generating substrate may be at least partially connected to an adjacent strand or strands along the length of the strand. For example, adjacent strands may be connected by one or more fibers. This may occur, for example, when strands are formed due to splitting of a sheet of homogenized plant material during manufacture of the aerosol-generating substrate, as described above.

[0063] The homogenized plant material may be a homogenized tobacco material including tobacco particles. The sheet of homogenized tobacco material may have a tobacco content of at least about 40 weight percent on a dry weight basis, more preferably at least about 50 weight percent on a dry weight basis, more preferably at least about 70 weight percent on a dry weight basis, and most preferably at least about 90 weight percent on a dry weight basis.

[0064] In the context of the present invention, the term "tobacco particles" refers to particles of any plant member of the Nicotiana species. The term "tobacco particles" includes ground or powdered tobacco lamina, ground or powdered tobacco stems, tobacco dust, tobacco fines, and other particulate tobacco by-products formed during tobacco processing, handling, and shipping. Preferably, the tobacco particles are substantially entirely derived from tobacco lamina. In contrast, isolated nicotine and nicotine salts, although compounds derived from tobacco, are not considered tobacco particles for the purposes of the present invention and are not included in the percentage of particulate plant material.

[0065] The homogenized plant material may further include one or more aerosol formers. Upon volatilization, the aerosol formers can carry other vaporized compounds released from the aerosol-generating substrate upon heating, such as nicotine and flavorants in the aerosol. Aerosol formers suitable for inclusion in the homogenized plant material are known in the art and include, but are not limited to, polyhydric alcohols (such as triethylene glycol, propylene glycol, 1,3-butanediol, and glycerol), esters of polyhydric alcohols (such as glycerol mono-, di-, or triacetate), and aliphatic esters of mono-, di-, or polycarboxylic acids (such as dimethyl dodecanedioate and tetradecanedioate).

[0066] The homogenized plant material may have an aerosol former content of about 5 weight percent to about 30 weight percent on a dry weight basis (such as about 10 weight percent to about 25 weight percent on a dry weight basis, or about 15 weight percent to about 20 weight percent on a dry weight basis). The aerosol former may act as a humectant in the homogenized plant material.

[0067] As set forth above, the rod of aerosol-generating substrate may be surrounded by a wrapper. The wrapper surrounding the rod of aerosol-generating substrate may be a paper wrapper or a non-paper wrapper. Suitable paper wrappers for use in the present invention are known in the art and include, but are not limited to, cigarette paper and filter plug wrap. Suitable non-paper wrappers for use in the present invention are known in the art and include, but are not limited to, sheets of homogenized tobacco material.

[0068] The paper wrapper may have a basis weight of at least 15 gsm, preferably at least 20 gsm. The paper wrapper may have a basis weight of 35 gsm or less, preferably 30 gsm or less. The paper wrapper may have a basis weight of 15 gsm to 35 gsm, preferably 20 gsm to 30 gsm. The paper wrapper may have a basis weight of 25 gsm. The paper wrapper may have a thickness of at least 25 micrometers, preferably at least 30 micrometers, more preferably at least 35 micrometers. The paper wrapper may have a thickness of about 55 micrometers or less, preferably about 50 micrometers or less, more preferably about 45 micrometers or less. The paper wrapper may have a thickness of 25 micrometers to 55 micrometers, preferably 30 micrometers to 50 micrometers, more preferably 35 micrometers to 45 micrometers. The paper wrapper may have a thickness of 40 microns.

[0069] The wrapper may be formed from a laminate material comprising multiple layers. Preferably, the wrapper is formed from an aluminum co-laminate sheet. The use of an aluminum-containing co-laminate sheet advantageously prevents combustion of the aerosol-generating substrate if the aerosol-generating substrate is to be ignited rather than heated in the intended manner.

[0070] The paper layer of the co-laminate sheet may have a basis weight of at least 35 gsm, preferably at least 40 gsm. The paper layer of the co-laminate sheet may have a basis weight of 55 gsm or less, preferably 50 gsm or less. The paper layer of the co-laminate sheet may have a basis weight of 35 gsm to 55 gsm, preferably 40 gsm to 50 gsm. The paper layer of the co-laminate sheet may have a basis weight of 45 gsm.

[0071] The paper layer of the co-laminate sheet may have a thickness of at least 50 micrometers, preferably at least 55 micrometers, more preferably at least 60 micrometers. The paper layer of the co-laminate sheet may have a thickness of 80 micrometers or less, preferably 75 micrometers or less, more preferably 70 micrometers or less.

[0072] The paper layer of the co-laminate sheet may have a thickness of about 50 micrometers to about 80 micrometers, preferably about 55 micrometers to about 75 micrometers, more preferably about 60 micrometers to about 70 micrometers. The paper layer of the co-laminate sheet may have a thickness of 65 microns.

[0073] The metal layer of the co-laminate sheet may have a basis weight of at least 12 gsm, preferably at least 15 gsm. The metal layer of the co-laminate sheet may have a basis weight of 25 gsm or less, preferably 20 gsm or less. The metal layer of the co-laminate sheet may have a basis weight of 12 gsm to 25 gsm, preferably 15 gsm to 20 gsm. The metal layer of the co-laminate sheet may have a basis weight of 17 gsm.

[0074] The metal layer of the co-laminate sheet may have a thickness of at least 2 micrometers, preferably at least 3 micrometers, more preferably at least 5 micrometers. The metal layer of the co-laminate sheet may have a thickness of 15 micrometers or less, preferably 12 micrometers or less, more preferably 10 micrometers or less.

[0075] The metal layer of the co-laminate sheet may have a thickness of about 2 micrometers to about 15 micrometers, preferably about 3 micrometers to about 12 micrometers, more preferably about 5 micrometers to about 10 micrometers. The metal layer of the co-laminate sheet may have a thickness of 6 microns.

[0076] The wrapper surrounding the rod of aerosol-generating substrate may be a paper wrapper containing PVOH (polyvinyl alcohol) or silicon. The addition of PVOH (polyvinyl alcohol) or silicon may improve the grease barrier properties of the wrapper.

[0077] The PVOH or silicon is applied to the paper layer as a surface coating, such as being disposed on the outer surface of the paper layer of the wrapper surrounding the rod of the aerosol-generating substrate. The PVOH or silicon may be disposed on the outer surface of the paper layer of the wrapper and may form a layer. The PVOH or silicon may be disposed on the inner surface of the paper layer of the wrapper. The PVOH or silicon may be disposed on the inner surface of the paper layer of the aerosol-generating article and may form a layer. The PVOH or silicon may be disposed on the inner and outer surfaces of the paper layer of the wrapper. The PVOH or silicon may be disposed on the inner and outer surfaces of the paper layer of the wrapper and may form a layer.

[0078] The PVOH or silicon containing paper wrapper may have a basis weight of at least 20 gsm, preferably at least 25 gsm, more preferably at least 30 gsm. The PVOH or silicon containing paper wrapper may have a basis weight of 50 gsm or less, preferably 45 gsm or less, more preferably 40 gsm or less. The PVOH or silicon containing paper wrapper may have a basis weight of 20 gsm to 50 gsm, preferably 25 gsm to 45 gsm, more preferably 30 gsm to 40 gsm. The PVOH or silicon containing paper wrapper may have a basis weight of about 35 gsm.

[0079] The PVOH or silicon-containing paper wrapper may have a thickness of at least 25 micrometers, preferably at least 30 micrometers, more preferably at least 35 micrometers. The PVOH or silicon-containing paper wrapper may have a thickness of 50 micrometers or less, preferably 45 micrometers or less, more preferably 40 micrometers or less. The PVOH or silicon-containing paper wrapper may have a thickness of 25 micrometers to 50 micrometers, preferably 30 micrometers to 45 micrometers, more preferably 35 micrometers to 40 micrometers. The PVOH or silicon-containing paper wrapper may have a thickness of 37 micrometers.

[0080] As mentioned in this disclosure, the present invention preferably comprises at least one air channeling element or segment. The downstream section of the aerosol-generating article may comprise an air channeling element. Such an air channeling element may be referred to as a downstream air channeling element, an aerosol cooling element, or a support element.

[0081] The upstream section of the aerosol-generating article may comprise an air channeling element, which may be referred to as an upstream air channeling element, an upstream element, or a front plug.

[0082] Both the upstream and downstream sections of the aerosol-generating article may each comprise an air channelling element, and the features described in this disclosure in relation to the air channelling element may apply to the downstream air channelling element (i.e. the air channelling element located downstream of the rod of the aerosol-generating substrate) and the upstream air channelling element (i.e. the air channelling element located upstream of the rod of the aerosol-generating substrate), respectively.

[0083] The upstream air channeling element may abut the rod of the aerosol-generating substrate.The upstream air channeling element may abut the upstream end of the rod of the aerosol-generating substrate.The upstream air channeling element may be located upstream of the rod of the aerosol-generating substrate.The upstream air channeling element may be located at the upstream end of the aerosol-generating article.

[0084] The downstream air channeling element may abut the rod of the aerosol-generating substrate. The downstream air channeling element may abut the downstream end of the rod of the aerosol-generating substrate. The downstream air channeling element may be located downstream of the rod of the aerosol-generating substrate. The downstream air channeling element may be located between the rod of the aerosol-generating substrate and any other component or element of the downstream section, such as a hollow tubular element or a mouthpiece element. The downstream air channeling element may abut the mouthpiece element. The downstream air channeling element may abut the upstream end of the mouthpiece element. The downstream air channeling element may be located upstream of the downstream end of the aerosol-generating article.

[0085] The air channeling element of the present disclosure may comprise a body. The body of the air channeling element may comprise a core portion and a peripheral portion. The core portion and the peripheral portion may extend in a longitudinal direction. The peripheral portion may surround or circumscribe the core portion. The body is preferably a cylindrical body having a substantially circular cross section.

[0086] The core portion may comprise the centre of the body of the air channelling element. Preferably, the core portion of the body refers to a circular core portion located at the centre of the cross-section of the body.

[0087] The core portion of the body may have a radius that is at least 25 percent of the radius of the body. The core portion of the body may have a radius that is at least 30 percent of the radius of the body. The core portion of the body may have a radius that is at least 50 percent of the radius of the body. The core portion of the body may have a radius that is no greater than 80 percent of the radius of the body. The core portion of the body may have a radius that is no greater than 75 percent of the radius of the body.

[0088] The peripheral portion of the air channeling element may comprise an annular portion of the body surrounding the core portion. In other words, the peripheral portion may occupy the remainder of the cross-section of the body of the air channeling element. The peripheral portion may extend around the periphery of the air channeling element or between the periphery and the core portion.

[0089] The air channeling element may comprise an outer air passage. The outer air passage may be an external air passage. The outer air passage may be defined on an outer surface of the body of the air channeling element. The outer air passage may refer to an air passage located away from the central axis of the air channeling element. The outer air passage may be an internal air passage located within the material or body of the air channeling element, or an external air passage provided on the outer surface of the air channeling element. The outer air passage may be referred to as a peripheral air passage. The outer air passage may extend from one end of the air channeling element to the other end of the air channeling element. The outer air passage may extend from an upstream end of the air channeling element to a downstream end of the air channeling element.

[0090] The outer air passage may be an internal air passage. The outer air passage may be defined within the body of the air channeling element. The outer air passage may be defined within or at a peripheral portion of the body of the air channeling element. The outer air passage may be an internal passage or channel extending along the air channeling element.

[0091] The air channelling element may comprise one or more outer air passages. The air channelling element may comprise at least two outer air passages, preferably at least three outer air passages, more preferably at least four outer air passages. The outer air passages may be evenly or uniformly distributed within the air channelling element. The outer air passages may be evenly or uniformly distributed around a core portion of the air channelling element. The outer air passages in the form of an internal cavity or air passage or an external air passage preferably extend from an upstream end of the air channelling element to a downstream end of the air channelling element. The outer air passages in the form of an internal cavity or air passage or an external air passage preferably extend continuously from an upstream end of the air channelling element to a downstream end of the air channelling element.

[0092] The outer air passage may comprise grooves defined on an outer surface of the air channeling element. The air channeling element may comprise at least one groove. The air channeling element may comprise at least two grooves, preferably at least three grooves, more preferably at least four grooves, and even more preferably at least five grooves. The grooves may be evenly or uniformly distributed around a core portion of the air channeling element. The grooves may be evenly or uniformly distributed around a body of the air channeling element.

[0093] Any exterior air passage, interior air passage, or groove of an air channeling element may extend from one end of the air channeling element to the other end of the air channeling element. Any exterior air passage, interior air passage, or groove of an air channeling element may extend from an upstream end of the air channeling element to a downstream end of the air channeling element. Any exterior air passage, interior air passage, or groove of an air channeling element may extend continuously from an upstream end of the air channeling element to a downstream end of the air channeling element. Any exterior air passage, interior air passage, or groove of an air channeling element may extend unobstructed from an upstream end of the air channeling element to a downstream end of the air channeling element, such that air or aerosol can flow from one end of the air channeling element to the other end of the air channeling element.

[0094] Providing multiple exterior air passages, such as grooves or internal channels, increases the amount of air or aerosol flow likely through the peripheral portions of the air channeling element and through the peripheral portions of the aerosol-generating substrate, thereby increasing heat exchange and improving aerosol nucleation. In the case of downstream air channeling elements in particular, providing exterior air passages, preferably in the form of grooves, may improve heat exchange of the aerosol flowing through the exterior air passages due to the proximity of the aerosol to the exterior of the aerosol-generating article.

[0095] Each outer air passage may follow or may follow a substantially straight path. Each outer air passage may be substantially parallel to one another. Each outer air passage may follow a helical path. Each groove may follow a helical path around or on the outer surface of the air channeling element. By following or following a helical path, the outer air passage may effectively follow a longer path from the upstream end to the downstream end of the air channeling element, thereby providing a longer time for the aerosol to cool. Each groove may follow a sinusoidal path or any other wave-shaped path. The wave-shaped path may include a square wave, a triangular wave, or a sawtooth wave.

[0096] Each outer air passage may be defined by an internal cavity extending along the air channeling element. The outer air passages extending within the body of the air channeling element may have a substantially circular cross-section. The radius of such internal passages may be at least about 0.25 mm, preferably at least about 0.5 mm, and more preferably at least about 1 mm. The radius of such internal passages may be no greater than about 2 mm.

[0097] When the outer air passage or the peripheral air passage are defined internally within the material of the air channeling element, the outer air passage may be located at a distance away from the periphery of the air channeling element. When the outer air passage or the peripheral air passage are defined internally within the material of the air channeling element, each of the outer air passages or the outer air passage may be located at a distance away from the periphery of the air channeling element. Such distance may be about 2 mm or less, preferably about 1.5 mm or less, more preferably about 1 mm or less, and even more preferably about 0.75 mm or less. Such distance preferably refers to the distance measured from the outer edge of the outer air passage to the outermost edge or periphery of the air channeling element.

[0098] The depth of the outer air passage defined by the groove may be at least about 0.5 mm. The depth of the outer air passage defined by the groove may be at least about 0.7 mm. The depth of the outer air passage defined by the groove may be at least about 1 mm. The depth of the outer air passage defined by the groove may be about 1.5 mm or less. The depth of the outer air passage defined by the groove may be about 2 mm or less.

[0099] The ratio of the total cross-sectional area of ​​the outer air passages (in other words, the sum of all the outer air passages) to the total cross-sectional area of ​​the air channeling elements may be at least about 2.5 percent. Such ratio may be at least about 5 percent, preferably at least about 10 percent, more preferably at least about 15 percent, and even more preferably at least about 25 percent. The ratio of the total cross-sectional area of ​​the outer air passages to the total cross-sectional area of ​​the air channeling elements may be at least about 30 percent. The total cross-sectional area of ​​the air channeling elements may refer to the interior cross-sectional area of ​​the aerosol-generating article at the location of the air channeling elements.

[0100] The ratio of the total cross-sectional area of ​​the outer air passages to the total cross-sectional area of ​​the air channeling elements may be about 60 percent or less. The ratio of the total cross-sectional area of ​​the outer air passages to the total cross-sectional area of ​​the air channeling elements may be about 50 percent or less. The ratio of the total cross-sectional area of ​​the outer air passages to the total cross-sectional area of ​​the air channeling elements may be about 40 percent or less. The total cross-sectional area of ​​the air channeling elements may refer to the cross-sectional area of ​​the air channeling elements if the air channeling elements were completely solid. In other words, the total cross-sectional area of ​​the air channeling elements may be based on the maximum outer diameter of the air channeling elements. As mentioned above, the outer air passages may comprise grooves defined on the outer surface of the air channeling elements.

[0101] Either the upstream or downstream air channeling element may be wrapped by a wrapper. Such a wrapper may have features according to any wrapper described in this disclosure. The wrapper surrounding the air channeling element may be substantially impermeable. In embodiments including one or more grooves on the outer surface of the air channeling element, the wrapper surrounding the air channeling element may define the boundaries of one or more outer air passages, which may be defined by the one or more grooves. In other words, the one or more outer air passages of the air channeling element may be defined by the wrapper and the one or more grooves.

[0102] In embodiments where the outer air passage is defined by one or more grooves around the periphery of the air channeling element, the outer surface of the air channeling element defined by the grooves may define a wetting surface, and the outer surface of the air channeling element not defined by the grooves may define a non-wetting surface. The term "wetting surface" refers to the surface of the air channeling element configured to contact the air or aerosol moving through the grooves. A "non-wetting surface" may contact a wrapper that surrounds the air channeling element. In the present disclosure, the term "outer surface" of an air channeling element preferably refers to the outer longitudinal surface of the air channeling element that extends parallel to the longitudinal direction of the air channeling element or aerosol-generating article.

[0103] The ratio of the wetted surface area of ​​the air channeling element to the non-wetted surface area of ​​the air channeling element may be at least about 25 percent. The ratio of the wetted surface area of ​​the air channeling element to the non-wetted surface area of ​​the air channeling element may be at least about 50 percent. The ratio of the wetted surface area of ​​the air channeling element to the non-wetted surface area of ​​the air channeling element may be at least about 1.

[0104] The ratio of the wetted surface area of ​​the air channeling element to the non-wetted surface area of ​​the air channeling element may be about 3 or less. The ratio of the wetted surface area of ​​the air channeling element to the non-wetted surface area of ​​the air channeling element may be about 2.5 or less. The ratio of the wetted surface area of ​​the air channeling element to the non-wetted surface area of ​​the air channeling element may be about 2 or less.

[0105] The core portion of the air channeling element is preferably substantially solid. This may advantageously prevent inadvertent discharge or migration of the aerosol-generating substrate material and may encourage air or aerosol to flow through any air passages present in the peripheral portion of the air channeling element. In other words, the core portion of the air channeling element may not include or define a central interior cavity extending along the air channeling element. Thus, the outer air passage or groove of the air channeling element may be the primary or only path for air or aerosol to travel through the air channeling element towards the aerosol-generating substrate or towards the downstream end of the aerosol-generating article.

[0106] The air channeling element may comprise one or more inner air passages. The air channeling element may comprise at least two inner air passages. A core portion of the air channeling element may define one or more inner air passages. The one or more inner air passages may be surrounded by one or more outer air passages. Each inner air passage may be defined as a longitudinal air channel or cavity extending along the air channeling element. Each inner air passage may extend from an upstream end of the air channeling element to a downstream end of the air channeling element. Each inner air passage may extend continuously from an upstream end of the air channeling element to a downstream end of the air channeling element.

[0107] The material of the air channeling element may be porous. However, pores or voids inherent in the material of the air channeling element may not be considered to define the interior air passage(s) or exterior air passage(s) of the air channeling element. In other words, any air passages are preferably formed within the material or body of the air channeling element through the manufacturing process.

[0108] The ratio of the total cross-sectional area of ​​any of the inner air passages to the total cross-sectional area of ​​the air channeling elements may be at least about 1 percent (or 0.01). The ratio of the total cross-sectional area of ​​any of the inner air passages to the total cross-sectional area of ​​the air channeling elements may be at least about 5 percent (or 0.05). The ratio of the total cross-sectional area of ​​any of the inner air passages to the total cross-sectional area of ​​the air channeling elements may be at least about 7.5 percent (or 0.075).

[0109] The ratio of the total cross-sectional area of ​​any of the inner air passages to the total cross-sectional area of ​​the air channeling elements may be about 20 percent (or 0.2) or less. The ratio of the total cross-sectional area of ​​any of the inner air passages to the total cross-sectional area of ​​the air channeling elements may be about 15 percent or less. The ratio of the total cross-sectional area of ​​any of the inner air passages to the total cross-sectional area of ​​the air channeling elements may be about 10 percent or less.

[0110] The ratio of the total cross-sectional area of ​​the outer air passages to the total cross-sectional area of ​​any inner air passages may be at least about 0.5. The ratio of the total cross-sectional area of ​​the outer air passages to the total cross-sectional area of ​​any inner air passages may be at least about 1. The ratio of the total cross-sectional area of ​​the outer air passages to the total cross-sectional area of ​​any inner air passages may be at least about 1.5. The ratio of the total cross-sectional area of ​​the outer air passages to the total cross-sectional area of ​​any inner air passages may be at least about 2. The ratio of the total cross-sectional area of ​​the outer air passages to the total cross-sectional area of ​​any inner air passages may be at least about 3. The ratio of the total cross-sectional area of ​​the outer air passages to the total cross-sectional area of ​​any inner air passages may be at least about 4. The ratio of the total cross-sectional area of ​​the outer air passages to the total cross-sectional area of ​​any inner air passages may be at least about 5. The ratio of the total cross-sectional area of ​​the outer air passages to the total cross-sectional area of ​​any inner air passages may be at least about 6.

[0111] The ratio of the total cross-sectional area of ​​the outer air passages to the total cross-sectional area of ​​any inner air passages may be about 10 or less. The ratio of the total cross-sectional area of ​​the outer air passages to the total cross-sectional area of ​​any inner air passages may be about 7.5 or less. The ratio of the total cross-sectional area of ​​the outer air passages to the total cross-sectional area of ​​any inner air passages may be about 5 or less.

[0112] The length of the air channeling element may be at least about 4 mm. The length of the air channeling element may be at least about 5 mm. The length of the air channeling element may be at least about 6 mm. The length of the air channeling element may be at least about 7 mm. The length of the air channeling element may be at least about 10 mm. The length of the air channeling element may be at least about 12 mm. The length of the air channeling element may be at least about 17 mm.

[0113] The length of the air channeling element may be about 50 mm or less. The length of the air channeling element may be about 25 mm or less. The length of the air channeling element may be about 23 mm or less. The length of the air channeling element may be about 20 mm or less. The length of the air channeling element may be about 15 mm or less.

[0114] The length of the air channeling element may be from about 4 mm to about 50 mm, preferably from about 4 mm to about 30 mm, more preferably from about 4 mm to about 25 mm. The length of the air channeling element may be from about 4 mm to about 50 mm, preferably from about 7 mm to about 30 mm, more preferably from about 10 mm to about 25 mm. The length of the air channeling element may be from about 12 mm to about 20 mm. The length of the air channeling element may be from about 10 mm to about 15 mm. The length of the air channeling element may be from about 17 mm to about 23 mm.

[0115] Preferably, the length of the air channelling element may be about 12mm. The length of the air channelling element may be about 16mm. The length of the air channelling element may be about 20mm.

[0116] Preferably, the length of the downstream air channeling element may be about 12mm. The length of the downstream air channeling element may be about 16mm. The length of the downstream air channeling element may be about 20mm.

[0117] Preferably, the length of the upstream air channeling element may be about 4mm. The length of the upstream air channeling element may be about 5mm. The length of the upstream air channeling element may be about 6mm.

[0118] When both upstream and downstream air channelling elements are provided within the same aerosol-generating article, it is preferred that the length of the downstream air channelling element is greater than the length of the upstream air channelling element.

[0119] The air channelling element preferably has an outer diameter approximately equal to the outer diameter of the rod of the aerosol-generating substrate and the outer diameter of the aerosol-generating article. This ensures that the ends of any grooves or air passages in the air channelling element are blocked by the aerosol-generating substrate. In other words, the cross-section of any groove or air passage in the air channelling element may overlap with the cross-section of the aerosol-generating substrate. The cross-section of any groove or air passage in the air channelling element may completely overlap with the cross-section of the aerosol-generating substrate. The cross-section of any groove or air passage in the air channelling element when projected onto the aerosol-generating substrate may be within the cross-section of the aerosol-generating substrate, particularly when the air channelling element and the aerosol-generating substrate are assembled and aligned within the aerosol-generating article.

[0120] The air channeling element may have an outer diameter of 5 millimeters to 12 millimeters, such as 5 millimeters to 10 millimeters, or 6 millimeters to 8 millimeters. The air channeling element may have an outer diameter of 7.2 millimeters plus or minus 10 percent.

[0121] The air channeling element (or its body) may be formed by thermoforming. The grooves defined on the air channeling element may be formed by thermoforming. Thermoforming may advantageously provide a cost-effective and efficient manufacturing process for the air channeling element, especially when provided with external grooves. The air channeling element may be made by injection molding or extrusion.

[0122] The air channeling element (or its body) may comprise (or be formed by) a polymeric material. The air channeling element (or its body) may comprise (or be formed by) a plastic material. The air channeling element (or its body) may comprise (or be formed by) a thermoplastic material. The air channeling element (or its body) may comprise (or be formed by) polyethylene (PE). The air channeling element (or its body) may comprise (or be formed by) cellulose acetate.

[0123] The air channeling element may include or be formed by a substantially impermeable material. The air channeling element may include or be formed by a substantially impermeable material. The material of the air channeling element may be substantially impermeable. The use of a substantially impermeable material may force air or aerosol to flow only through the inner air passage or the outer air passage of the air channeling element.

[0124] The air channeling element may comprise (or be formed by) paper. The air channeling element may comprise cardboard. The air channeling element may be formed from extruded paper.

[0125] An aerosol-generating article according to the present disclosure comprises an upstream section located upstream of the rod of aerosol-generating substrate. The upstream section is preferably located immediately upstream of the rod of aerosol-generating substrate. The upstream section preferably extends between the upstream end of the aerosol-generating article and the rod of aerosol-generating substrate.

[0126] The upstream section includes an upstream element located upstream of the rod of the aerosol-generating substrate. Suitable upstream elements are described within this disclosure. The upstream element may be an upstream plug element (or front plug). The upstream element may be an upstream hollow tubular element. The upstream element may be an upstream air channeling element.

[0127] The upstream element is preferably an upstream air channelling element. The upstream air channelling element may abut the rod of the aerosol-generating substrate. The upstream air channelling element may abut the upstream end of the rod of the aerosol-generating substrate. The upstream air channelling element may be located upstream of the rod of the aerosol-generating substrate. The upstream air channelling element may be located at the upstream end of the aerosol-generating article.

[0128] Thus, the upstream element or upstream air channeling element may include features associated with air channeling elements, as described in this disclosure. Similarly, features described herein in relation to the upstream element may also be present in the upstream air channeling element.

[0129] In addition to the air channeling benefits associated with the air channeling elements described herein, the upstream element advantageously prevents direct physical contact with the upstream end of the aerosol-generating substrate. For example, if the aerosol-generating substrate comprises a susceptor element, the upstream element may prevent direct physical contact with the upstream end of the susceptor element. This helps to prevent displacement or deformation of the susceptor element during handling or transport of the aerosol-generating article. This in turn helps to fix the shape and position of the susceptor element.

[0130] Furthermore, the presence of the upstream element helps to prevent any loss of the substrate, which may be advantageous, for example, when the substrate contains particulate plant material.

[0131] Where the aerosol-generating substrate comprises cut tobacco, such as tobacco cut filler, the upstream section, or elements thereof, may additionally serve to prevent loss of loose particles of tobacco from the upstream end of the article.

[0132] The upstream section, or upstream elements thereof, may also provide at least some coverage to the upstream end of the aerosol-generating substrate that might otherwise be exposed, and therefore may additionally provide some degree of protection to the aerosol-generating substrate during storage.

[0133] In the case of an aerosol-generating article intended to be inserted into a cavity in an aerosol-generating device so that the aerosol-generating substrate can be externally heated within the cavity, the upstream section or an upstream element thereof may advantageously facilitate insertion of the upstream end of the article into the cavity. The inclusion of an upstream element may provide additional protection for the end of the rod of the aerosol-generating substrate during insertion of the article into the cavity, thereby minimizing the risk of damage to the substrate.

[0134] The upstream section, or upstream elements thereof, may also provide an improved appearance to the upstream end of the aerosol-generating article. Furthermore, if desired, the upstream section, or upstream elements thereof, may be used to provide information about the aerosol-generating article, such as information about the brand, flavor, contents, or details of the aerosol-generating device with which the article is intended to be used.

[0135] The upstream element may be a porous plug element. Preferably, the upstream element has a porosity of at least about 50 percent along the longitudinal axis of the aerosol-generating article. More preferably, the upstream element has a porosity of between about 50 percent and about 90 percent along the longitudinal axis. The porosity of the upstream element along the longitudinal axis is defined as the ratio of the cross-sectional area of ​​the material forming the upstream element to the internal cross-sectional area of ​​the aerosol-generating article at the location of the upstream element.

[0136] The upstream element may be made of a porous material or may comprise a plurality of openings, which may be achieved, for example, by laser drilling, and the plurality of openings are preferably uniformly distributed across the cross section of the upstream element.

[0137] The porosity or permeability of the upstream element may advantageously be designed to provide an aerosol-generating article with a particular overall resistance to draw (RTD) without substantially affecting the filtration provided by other portions of the article.

[0138] The upstream element may be formed from a material that is impermeable to air. In such embodiments, the aerosol-generating article may be configured to allow air to flow into the rod of aerosol-generating substrate through suitable vent means provided in the wrapper.

[0139] It may be desirable to minimize the RTD of the upstream element. For example, this may be the case for an article that is intended to be inserted into the cavity of an aerosol generating device, such that the aerosol generating substrate is externally heated, as described herein. For such articles, it is desirable to provide the article with the lowest possible RTD, so that the majority of the consumer's RTD experience is provided by the aerosol generating device, not the article.

[0140] Preferably, the RTD of the upstream element is about 10 millimeters of H2O or less. More preferably, the RTD of the upstream element is about 5 millimeters of H2O or less. Even more preferably, the RTD of the upstream element is about 2.5 millimeters of H2O or less. Even more preferably, the RTD of the upstream element is about 2 millimeters of H2O or less.

[0141] The RTD of the upstream element may be at least 0.1 millimeters of H2O, or at least about 0.25 millimeters of H2O, or at least about 0.5 millimeters of H2O.

[0142] The RTD of the upstream element may be about 0.1 millimeters H2O to about 10 millimeters H2O, preferably about 0.25 millimeters H2O to about 10 millimeters H2O, preferably about 0.5 millimeters H2O to about 10 millimeters H2O. The RTD of the upstream element may be about 0.1 millimeters H2O to about 5 millimeters H2O, preferably about 0.25 millimeters H2O to about 5 millimeters H2O, preferably about 0.5 millimeters H2O to about 5 millimeters H2O. The RTD of the upstream element may be about 0.1 millimeters H2O to about 2.5 millimeters H2O, preferably about 0.25 millimeters H2O to about 2.5 millimeters H2O, more preferably about 0.5 millimeters H2O to about 2.5 millimeters H2O. The RTD of the upstream element is from about 0.1 millimeters HO to about 2 millimeters HO, preferably from about 0.25 millimeters HO to about 2 millimeters HO, more preferably from about 0.5 millimeters HO to about 2 millimeters HO, and the RTD of the upstream element may be about 1 millimeter HO.

[0143] It is preferred that the upstream element has an RTD of less than about 2 millimeters of H2O per millimeter of length, more preferably less than about 1.5 millimeters of H2O per millimeter of length, more preferably less than about 1 millimeter of H2O per millimeter of length, more preferably less than about 0.5 millimeters of H2O per millimeter of length, more preferably less than about 0.3 millimeters of H2O per millimeter of length, and more preferably less than about 0.2 millimeters of H2O per millimeter of length.

[0144] The upstream section or upstream element preferably has an outer diameter approximately equal to the outer diameter of the aerosol-generating article. Preferably, the upstream section or upstream element has an outer diameter of about 6 mm to about 8 mm, more preferably about 7 mm to about 7.5 mm. Preferably, the upstream section or upstream element has an outer diameter of about 7.1 mm.

[0145] Preferably, the upstream section or element has a length of about 2 millimeters to about 8 millimeters, more preferably about 3 millimeters to about 7 millimeters, more preferably about 4 millimeters to about 6 millimeters. The upstream section or element may have a length of about 5 millimeters.

[0146] The length of the upstream section or element may be advantageously varied to provide a desired overall length of the aerosol-generating article For example, if it is desired to reduce the length of one of the other components of the aerosol-generating article, the length of the upstream section or element may be increased to maintain the same overall length of the article.

[0147] For articles that are intended to be externally heated, the length of the upstream section, or an upstream element thereof, can be used to control the position of the aerosol-generating article within the cavity of the aerosol-generating device. This can advantageously ensure that the position of the aerosol-generating substrate within the cavity can be optimized for heating, and also the position of any ventilation.

[0148] The upstream section is preferably surrounded by a wrapper, such as a plug wrap. The wrapper surrounding the upstream section is preferably a stiff plug wrap, for example a plug wrap having a basis weight of at least about 80 grams per square meter (gsm), or at least about 100 gsm, or at least about 110 gsm. This provides structural rigidity to the upstream section.

[0149] The upstream section is preferably connected to the rod of the aerosol-generating substrate, and optionally to at least a portion of the downstream section, by an outer wrapper.

[0150] As mentioned above, the aerosol-generating article according to the invention comprises a downstream section located downstream of the rod of aerosol-generating substrate. The downstream section is preferably located immediately downstream of the rod of aerosol-generating substrate. The downstream section of the aerosol-generating article preferably extends between the rod of aerosol-generating substrate and the downstream end of the aerosol-generating article. The downstream section may comprise one or more elements, each of which are described in more detail within this disclosure.

[0151] The length of the downstream section may be at least about 15 mm. The length of the downstream section may be at least about 20 mm. The length of the downstream section may be at least about 24 mm. The length of the downstream section may be at least about 26 mm.

[0152] The length of the downstream section may be about 36 mm or less (in other words, less than). The length of the downstream section may be about 32 mm or less. The length of the downstream section may be about 30 mm or less.

[0153] The length of the downstream section may be from about 15 mm to about 36 mm. The length of the downstream section may be from about 20 mm to about 36 mm. The length of the downstream section may be from about 24 mm to about 32 mm. The length of the downstream section may be from about 26 mm to about 30 mm.

[0154] The downstream section preferably comprises an air channelling element according to the present disclosure. The downstream air channelling element may be located downstream of the rod of the aerosol-generating substrate. The downstream air channelling element may be located adjacent to the rod of the aerosol-generating substrate. The downstream air channelling element may abut the downstream end of the rod of the aerosol-generating substrate.

[0155] The downstream section preferably comprises a hollow tubular element. Preferably, the downstream section comprises a mouthpiece element. The downstream section may comprise or consist of a hollow tubular element and a mouthpiece element, the hollow tubular element being located between the rod of the aerosol-generating substrate and the mouthpiece element. The hollow tubular element may abut against the rod of the aerosol-generating substrate and the mouthpiece element.

[0156] Where the downstream section comprises a downstream air channelling element, the hollow tubular element may be located downstream of the downstream air channelling element. The hollow tubular element may abut the downstream air channelling element. The hollow tubular element may be located between the downstream air channelling element and the mouthpiece element.

[0157] Providing a relatively long downstream section ensures that an appropriate length of the aerosol-generating article protrudes from the aerosol generating device when the article is received in the aerosol generating device. Such an appropriate protruding length facilitates ease of insertion and extraction of the article from the device, which also ensures that the upstream portion of the article is properly inserted into the device, particularly with reduced risk of damage during insertion.

[0158] The term "hollow tubular segment" or "hollow tubular element" as used throughout this disclosure generally refers to an elongated element that defines a lumen or airflow passage along its longitudinal axis. In particular, the term "tubular" is used below with respect to a tubular element having a substantially cylindrical cross-section and defining at least one airflow conduit that establishes uninterrupted fluid communication between the upstream end of the tubular element and the downstream end of the tubular element. However, it will be appreciated that alternative shapes (e.g. alternative cross-sectional shapes) of the tubular segment may be possible. A hollow tubular segment or element may be an individual, separate element of an aerosol-generating article having a defined length and thickness. In this specification, a "hollow tubular segment" or "hollow tubular element" may also be referred to as a "hollow tube" or "hollow tube segment".

[0159] The internal volume defined by the hollow tubular element may be at least about 100 cubic millimeters. In other words, the volume of the cavity or lumen defined by the hollow tubular element may be at least about 100 cubic millimeters. Preferably, the internal volume defined by the hollow tubular element may be at least about 300 cubic millimeters. The internal volume defined by the hollow tubular element may be at least about 700 cubic millimeters.

[0160] The interior volume defined by the hollow tubular element may be about 1200 cubic millimeters or less. Preferably, the interior volume defined by the hollow tubular element may be about 1000 cubic millimeters or less. The interior volume defined by the hollow tubular element may be about 900 cubic millimeters or less.

[0161] The interior volume defined by the hollow tubular element may be between about 100 and 1200 cubic millimeters. Preferably, the interior volume defined by the hollow tubular element may be between about 300 and about 1000 cubic millimeters. The interior volume defined by the hollow tubular element may be between about 700 and 900 cubic millimeters.

[0162] In the context of the present invention, a hollow tubular segment provides an unrestricted flow channel. This means that the hollow tubular segment provides a negligible level of resistance to withdrawal (RTD). The term "negligible level of RTD" is used to describe an RTD of less than 1 mmH2O per 10 millimeters long hollow tubular segment or hollow tubular element, preferably less than 0.4 mmH2O per 10 millimeters long hollow tubular segment or hollow tubular element, more preferably less than 0.1 mmH2O per 10 millimeters long hollow tubular segment or hollow tubular element.

[0163] Preferably, the RTD of the hollow tubular element is about 10 millimeters H2O or less. More preferably, the RTD of the hollow tubular element is about 5 millimeters H2O or less. Even more preferably, the RTD of the hollow tubular element is about 2.5 millimeters H2O or less. Even more preferably, the RTD of the hollow tubular element is about 2 millimeters H2O or less. Even more preferably, the RTD of the hollow tubular element is about 1 millimeter H2O or less.

[0164] The RTD of the hollow tubular element can be at least 0 millimeters H2O, or at least about 0.25 millimeters H2O, or at least about 0.5 millimeters H2O, or at least about 1 millimeter H2O.

[0165] The hollow tubular element may comprise one or more hollow tubular segments. Preferably, the hollow tubular element consists of one (single) hollow tubular segment. Preferably, the hollow tubular element consists of a continuous hollow tubular segment. The hollow tubular segment may comprise any of the features described in this disclosure in relation to hollow tubular elements.

[0166] As described within this disclosure, the aerosol-generating article may comprise a ventilation zone at a position along the aerosol-generating article. In the context of a ventilation zone, the term "position" preferably refers to a longitudinal position unless otherwise specified. The aerosol-generating article may comprise a ventilation zone at a location along the downstream section. The aerosol-generating article may comprise a ventilation zone at a position along the downstream air channeling element. In other words, the ventilation zone may be provided at a longitudinal position along the downstream air channeling element. The ventilation zone may be above the downstream air channeling element.

[0167] The aerosol-generating article may comprise ventilation zones at locations along the hollow tubular element. Such, or any ventilation zone, may extend through the peripheral wall of the hollow tubular element. In this way, fluid communication is established between the flow channel defined internally by the hollow tubular element and the external environment (in other words, the exterior of the aerosol-generating article). A ventilation zone may be provided at a location along the downstream air channeling element. Such a ventilation zone may extend through any wrapper or wrappers surrounding the air channeling element. Such a ventilation zone provided along the air channeling element may establish fluid communication between the exterior of the aerosol-generating article and one or more outer air passages (or grooves). Such a ventilation zone provided along the air channeling element may establish fluid communication from the exterior of the aerosol-generating article to one or more outer air passages (or grooves).

[0168] The length of the hollow tubular element may be at least about 8 mm. The length of the hollow tubular element may be at least about 10 mm. The length of the hollow tubular element may be at least about 15 mm. The length of the hollow tubular element may be at least about 19 mm.

[0169] The length of the hollow tubular element may be about 30 mm or less. The length of the hollow tubular element may be about 25 mm or less. The length of the hollow tubular element may be about 23 mm or less.

[0170] The length of the hollow tubular element may be about 8 mm to about 30 mm. The length of the hollow tubular element may be about 10 mm to about 30 mm. The length of the hollow tubular element may be about 15 mm to about 25 mm. The length of the hollow tubular element may be about 19 mm to about 23 mm.

[0171] The relatively long hollow tubular element provides and defines a relatively long internal cavity within the aerosol-generating article and downstream of the rod of the aerosol-generating substrate. As discussed in this disclosure, providing an empty cavity downstream (preferably immediately downstream) of the aerosol-generating substrate enhances nucleation of the aerosol particles generated by the substrate. Providing a relatively long cavity maximizes the benefits of such nucleation, thereby improving aerosol formation and cooling. Providing such a hollow tubular element downstream of the downstream air channeling element further enhances the aerosol formation and cooling benefits provided by the air channeling element itself.

[0172] The peripheral wall thickness (in other words, the wall thickness) of the hollow tubular element may be at least about 100 micrometers. The wall thickness of the hollow tubular element may be at least about 150 micrometers. The wall thickness of the hollow tubular element may be at least about 200 micrometers, preferably at least about 250 micrometers, and even more preferably at least about 500 micrometers (or 0.5 mm).

[0173] The wall thickness of the hollow tubular element may be about 2 millimeters or less, preferably about 1.5 millimeters or less, and even more preferably about 1.25 mm or less. The wall thickness of the hollow tubular element may be about 1 millimeter or less. The wall thickness of the hollow tubular element may be about 500 micrometers or less.

[0174] The wall thickness of the hollow tubular element may be from about 100 micrometers to about 2 millimeters, preferably from about 150 micrometers to about 1.5 millimeters, and even more preferably from about 200 micrometers to about 1.25 millimeters. The wall thickness of the hollow tubular element may preferably be about 250 micrometers (0.25 mm).

[0175] At the same time, maintaining the thickness of the peripheral wall of the hollow tubular segment relatively low ensures that the overall internal volume of the hollow tubular segment and the cross-sectional area of ​​the hollow tubular segment, which is available for the aerosol to initiate the nucleation process as soon as the aerosol components leave the rod of the aerosol-generating substrate, are effectively maximized, while at the same time ensuring that the hollow tubular segment has the necessary structural strength to prevent the collapse of the aerosol-generating article and provide some support to the rod of the aerosol-generating substrate, and that the RTD of the hollow tubular segment is minimized. It is understood that a larger value of the cross-sectional area of ​​the cavity of the hollow tubular segment is associated with a reduced velocity of the aerosol stream moving along the aerosol-generating article, which is expected to promote nucleation. Furthermore, it is understood that by utilizing a hollow tubular segment having a relatively low thickness, it is possible to substantially prevent the diffusion of the ventilation air before it comes into contact with and mixes with the aerosol stream, further favoring the nucleation phenomenon. In effect, by providing more controllably localized cooling of the stream of volatilized species, it is possible to enhance the cooling effect on the formation of new aerosol particles.

[0176] The hollow tubular element preferably has an outer diameter approximately equal to the outer diameter of the rod of the aerosol-generating substrate and the outer diameter of the aerosol-generating article.

[0177] The hollow tubular element may have an outer diameter of 5 millimeters to 12 millimeters, for example 5 millimeters to 10 millimeters, or 6 millimeters to 8 millimeters. The hollow tubular element may preferably have an outer diameter of 7.2 millimeters plus or minus 10 percent.

[0178] The hollow tubular element may have an inner diameter. Preferably, the hollow tubular element may have a constant inner diameter along the length of the hollow tubular element. However, the inner diameter of the hollow tubular element may vary along the length of the hollow tubular element.

[0179] The hollow tubular element may have an inner diameter of at least about 2 millimeters. For example, the hollow tubular element may have an inner diameter of at least about 4 millimeters, at least about 5 millimeters, or at least about 7 millimeters.

[0180] Providing a hollow tubular element with an inner diameter as set out above may advantageously provide the hollow tubular element with sufficient stiffness and strength.

[0181] The hollow tubular element may have an inner diameter of about 10 millimeters or less. For example, the hollow tubular element may have an inner diameter of about 9 millimeters or less, about 8 millimeters or less, or about 7.5 millimeters or less.

[0182] By providing the hollow tubular element with an inner diameter as described above, the resistance to withdrawal of the hollow tubular segment may be advantageously reduced.

[0183] The hollow tubular element may have an inner diameter of about 2 millimeters to about 10 millimeters, about 4 millimeters to about 9 millimeters, about 5 millimeters to about 8 millimeters, or about 6 millimeters to about 7.5 millimeters.

[0184] The hollow tubular element may have an outer diameter of about 7.1 or 7.2 mm. The hollow tubular element may have an inner diameter of about 6.7 millimeters.

[0185] The hollow tubular segment may comprise a paper-based material. The hollow tubular segment may comprise at least one layer of paper. The paper may be a very stiff paper. The paper may be a crimped paper, such as crimped heat-resistant paper or crimped parchment paper.

[0186] Preferably, the hollow tubular element may comprise cardboard. The hollow tubular element may be a cardboard tube. The hollow tubular element may be formed from cardboard. Advantageously, cardboard is a cost-effective material that provides a balance between being deformable to provide ease of insertion of the article into the aerosol generating device and being sufficiently rigid to provide proper engagement of the article with the interior of the device. Thus, a cardboard tube may provide suitable resistance to deformation or compression during use.

[0187] The hollow tubular segment may be a paper tube. The hollow tubular segment may be a tube formed from spirally wound paper. The hollow tubular segment may be formed from multiple layers of paper. The paper may have a basis weight of at least about 50 grams per square meter, at least about 60 grams per square meter, at least about 70 grams per square meter, or at least about 90 grams per square meter.

[0188] The hollow tubular segment may comprise a polymeric material. For example, the hollow tubular segment may comprise a polymeric film. The polymeric film may comprise a cellulose film. The hollow tubular segment may comprise low density polyethylene (LDPE) or polyhydroxyalkanoate (PHA) fibers. The hollow tube may comprise cellulose acetate tow.

[0189] As mentioned above, the aerosol-generating article according to the invention comprises a downstream section comprising a hollow tubular element located downstream of the rod of aerosol-generating substrate and abutting the downstream end of the rod of aerosol-generating substrate. Furthermore, the aerosol-generating article according to the invention comprises a ventilation zone along the hollow tubular element. The aerosol-generating article according to the invention may also comprise a ventilation zone along the downstream air channelling element.

[0190] In this way, a vented cavity is provided downstream of the rod of the aerosol-generating substrate, either in the form of vent grooves or external air passages in an air channeling element, or in the form of an internal vented cavity in a hollow tubular element, which offers several potential technical advantages.

[0191] First, the inventors have found that one such vented hollow tubular or air channeling element provides particularly efficient cooling of the aerosol. Hence, satisfactory cooling of the aerosol can be achieved even with a relatively short downstream section. This is particularly desirable because it allows the provision of an aerosol-generating article in which the aerosol-generating substrate (and particularly those containing tobacco) is heated rather than combusted, combining satisfactory aerosol delivery with efficient cooling of the aerosol to a temperature desirable for the consumer.

[0192] Second, the inventors have surprisingly found that such rapid cooling of volatile species released upon heating of the aerosol-generating substrate promotes and enhances the nucleation of aerosol particles. This effect is particularly felt when the aeration zone is located at a precisely defined position downstream of the rod of the aerosol-generating substrate, as will be explained in more detail below. In fact, the inventors have found that the favorable effect of enhanced nucleation has the ability to significantly counteract the potentially less desirable effect of dilution induced by the introduction of ventilation air.

[0193] Similarly, ventilation zones may be located along the downstream air channeling elements to provide similar benefits by providing ventilation at such locations.

[0194] The ventilation zone may typically include a plurality of perforations through the peripheral wall of the hollow tubular element. The ventilation zone may typically comprise a plurality of perforations extending through the peripheral wall of the hollow tubular element. The ventilation zone may extend through the material of the air channeling element to provide fluid communication between any outer air passages (which may not be grooves provided on the outer surface of the air channeling element) and the exterior of the aerosol-generating article. Thus, the ventilation zone may comprise a plurality of perforations extending through the material of the air channeling element to provide fluid communication between any outer air passages and the exterior of the aerosol-generating article.

[0195] The ventilation zone may comprise a plurality of perforations through the wrapper surrounding the air channeling element. The ventilation zone may comprise a plurality of perforations extending through the wrapper surrounding the air channeling element. The ventilation zone may comprise a plurality of perforations extending through the material of the air channeling element to provide fluid communication with one or more outer air passages. Similar benefits to ventilation zones provided along the hollow tubular element are achieved by ventilation zones provided along the downstream air channeling element, but in the case of an aerosol-generating article, may not include a hollow tubular element. The ventilation zone along the air channeling element may provide fluid communication with the outer air passage or groove of the air channeling element, and the aerosol flow may be arranged to move. Such ventilation zones provided along the air channeling element may establish fluid communication between the exterior of the aerosol-generating article and one or more outer air passages. Such ventilation zones provided along the air channeling element may establish fluid communication from the exterior of the aerosol-generating article to one or more outer air passages. Such ventilation zones may extend through the material of the air channeling element to provide fluid communication between any outer air passages (which may not be grooves provided on the outer surface of the air channeling element) and the exterior of the aerosol-generating article.

[0196] The ventilation zone preferably comprises at least one circumferential row of perforations. The ventilation zone may comprise two circumferential rows of perforations. For example, the perforations may be formed on-line during manufacture of the aerosol-generating article. Each circumferential row of perforations preferably comprises between 8 and 30 perforations.

[0197] Aerosol-generating articles according to the present invention may have a breathability level of at least about 2 percent.

[0198] The term "ventilation level" is used throughout this specification to mean the volume ratio between the airflow entering the aerosol-generating article via the ventilation zone (ventilation airflow) and the sum of the aerosol airflow and the ventilation airflow. The higher the ventilation level, the higher the dilution of the aerosol stream delivered to the consumer. The aerosol-generating article preferably has a ventilation level of at least 5 percent, more preferably at least 10 percent, and even more preferably at least 12 percent or at least 15 percent.

[0199] Aerosol-generating articles according to the invention may have a breathability level of up to about 90 percent. Preferably, aerosol-generating articles according to the invention have a breathability level of no more than 80 percent, more preferably no more than 70 percent, even more preferably no more than 60 percent, and most preferably no more than 50 percent.

[0200] Without wishing to be bound by theory, the inventors have found that the temperature reduction caused by admitting cooler outside air through the ventilation zone into the hollow tubular element or downstream air channeling element (particularly its outer air passages or grooves) can have a beneficial effect on aerosol particle nucleation and growth.

[0201] The formation of aerosols from gaseous mixtures containing various chemical species depends on a delicate interplay between nucleation, evaporation, condensation and even fusion, which accounts for the changes in vapor 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 remain coherent for a long time with a sufficient probability (e.g., one in two). These molecules represent a kind of critical, threshold molecular clusters in the temporary molecular aggregates, which means that smaller molecular clusters are generally prone to break down into the gas phase rather quickly, while larger clusters are generally prone to growth. These critical clusters are identified as the main nucleation cores from which droplets are expected to grow due to the condensation of molecules from the vapor. It is assumed that freshly nucleated raw droplets appear with a certain original diameter and may then grow by several orders of magnitude. This may be facilitated and enhanced by the rapid cooling of the surrounding vapor, which induces the condensation. In this regard, it is helpful to keep in mind that evaporation and condensation are two aspects of one and the same mechanism: gas-liquid mass transfer. Evaporation involves the net mass transfer from the droplets to the gas phase, while condensation is the net mass transfer from the gas phase to the droplet phase. Evaporation (or condensation) causes the droplets to shrink (or grow), but the number of droplets remains unchanged.

[0202] In this scenario (when the scenario is further complicated by fusion phenomena), the temperature and rate of cooling may play an important role in determining how the system responds. In general, different cooling rates may lead to significantly different temperature behaviors with respect to the formation of the liquid phase (droplets), since the nucleation process is typically nonlinear. Without wishing to be bound by theory, it is hypothesized that cooling can cause a rapid increase in the number of condensed droplets, followed by a short-term strong increase in this growth (nucleation burst). This nucleation burst appears to be more pronounced at lower temperatures. Furthermore, it appears that a faster cooling rate may favor the onset of early nucleation. In contrast, a decrease in the cooling rate appears to have a favorable effect on the final size that the aerosol droplets eventually reach.

[0203] Thus, the rapid cooling caused by admitting ambient air through the ventilation zone into the hollow tubular element or downstream air channeling element (particularly its outer air passages or grooves) can be advantageously used to promote nucleation and growth of aerosol droplets. At the same time, however, admitting ambient air into the hollow tubular element or downstream air channeling element (particularly its outer air passages or grooves) has the direct disadvantage of diluting the aerosol stream delivered to the consumer.

[0204] The inventors have surprisingly found that the favorable effects of enhanced nucleation promoted by the rapid cooling induced by the introduction of ventilation air into the article can significantly counteract the undesirable effects of dilution. Thus, satisfactory values ​​of aerosol delivery are consistently achieved with the aerosol-generating articles according to the present invention.

[0205] The inventors have also surprisingly found that dilution effects on the aerosol, which can be assessed by measurement, specifically the effect on delivery of an aerosol former (e.g., glycerol) contained in the aerosol-generating substrate, are advantageously minimized when the aeration level is within the above-mentioned ranges.

[0206] Specifically, aeration levels of 10 percent to 20 percent, and even more preferably 12 to 18 percent, have been found to lead to particularly satisfactory values ​​of glycerol delivery.

[0207] This is particularly advantageous in "short" aerosol-generating articles, such as "short" aerosol-generating articles in which the length of the rod of the aerosol-generating substrate is less than about 40 millimeters, preferably less than 30 millimeters, even more preferably less than 25 millimeters, and especially preferably less than 20 millimeters, or in which the overall length of the aerosol-generating article is less than about 70 millimeters, preferably less than about 60 millimeters, and even more preferably less than 50 millimeters. As will be appreciated, in such aerosol-generating articles there is typically little time and space for the aerosol to form and for the particle phase of the aerosol to become available for delivery to the consumer, so that the benefits of enhanced nucleation discussed above are felt in a particularly significant manner.

[0208] The distance between the ventilation zone and the downstream end of the aerosol-generating article may be at least 10 millimeters. Preferably, the distance between the ventilation zone and the downstream end of the aerosol-generating article is at least 12 millimeters. More preferably, the distance between the ventilation zone and the downstream end of the aerosol-generating article is at least 15 millimeters.

[0209] Preferably, the distance between the ventilation zone and the downstream end of the aerosol-generating article is 21 millimeters or less. More preferably, the distance between the ventilation zone and the downstream end of the aerosol-generating article is 19 millimeters or less. Even more preferably, the distance between the ventilation zone and the downstream end of the aerosol-generating article is 17 millimeters or less.

[0210] The distance between the ventilation zone and the downstream end of the aerosol-generating article may be 10 mm to 21 mm, preferably 12 mm to 21 mm, more preferably 15 mm to 21 mm. The distance between the ventilation zone and the downstream end of the aerosol-generating article may be 10 mm to 19 mm, preferably 12 mm to 19 mm, more preferably 15 mm to 19 mm. The distance between the ventilation zone and the downstream end of the aerosol-generating article may be 10 mm to 17 mm, preferably 12 mm to 17 mm, more preferably 15 mm to 17 mm.

[0211] The ventilation zone may be located along the downstream air channeling element. Preferably, the distance between the ventilation zone and the downstream end of the downstream air channeling element is 10 millimeters or less. Preferably, the distance between the ventilation zone and the downstream end of the downstream air channeling element is 7 millimeters or less. Preferably, the distance between the ventilation zone and the downstream end of the downstream air channeling element is 5 millimeters or less. Preferably, the distance between the ventilation zone and the downstream end of the downstream air channeling element is 3 millimeters or less. Preferably, the ventilation zone is located along the downstream half of the downstream air channeling element.

[0212] Locating the ventilation zone some distance away from the downstream end of the aerosol-generating article within the ranges mentioned above has the advantage that, when the aerosol-generating article is partially received within the heating device during use, the portion of the aerosol-generating article that extends outside the heating device is long enough for a consumer to comfortably hold the article between their lips. At the same time, evidence suggests that the longer length of the portion of the aerosol-generating article that extends outside the heating device may make it easier to bend the aerosol-generating article in an inadvertent and undesirable manner, which may impair aerosol delivery or generally the intended use of the aerosol-generating article.

[0213] As discussed in this disclosure, the downstream section may comprise a mouthpiece element. The mouthpiece element may extend from a downstream end of the downstream section. The mouthpiece element may be located at a downstream end of the aerosol-generating article. The downstream end of the mouthpiece element may define the downstream end of the aerosol-generating article. The mouthpiece element may abut the air channeling element. As such, a hollow tubular element may not be provided.

[0214] A mouthpiece element may be provided downstream of the rod of aerosol-generating substrate. The mouthpiece element may extend all the way to the mouth end of the aerosol-generating article. The mouthpiece element may comprise at least one mouthpiece filter segment formed from a fibrous filtration material. The mouthpiece element may be located downstream of the hollow tubular element, as described above. The mouthpiece element may extend between the hollow tubular element and the downstream end of the aerosol-generating article.

[0215] Parameters or characteristics described in relation to the mouthpiece element as a whole may be equally applied to the mouthpiece filter segment of the mouthpiece element.

[0216] The fibrous filter material may be for filtering the aerosol generated from the aerosol-generating substrate. Suitable fibrous filter materials will be known to those skilled in the art. Particularly preferably, the at least one mouthpiece filter segment comprises a cellulose acetate filter segment formed from cellulose acetate tow.

[0217] The mouthpiece element may consist of a single mouthpiece filter segment. The mouthpiece element may include two or more mouthpiece filter segments axially aligned in abutting end-to-end relationship with one another.

[0218] The downstream section may comprise a mouth-end cavity at a downstream end downstream of the mouthpiece element as described above. The mouth-end cavity may be defined by a further hollow tubular element provided at the downstream end of the mouthpiece. The mouth-end cavity may be defined by an outer wrapper of the aerosol-generating article, the outer wrapper extending in a downstream direction from (or past) the mouthpiece element.

[0219] The mouthpiece element may optionally include a flavourant, which may be provided in any suitable form, for example, the mouthpiece element may comprise one or more capsules, beads, or granules of flavourant, or one or more threads or filaments loaded with flavour.

[0220] The mouthpiece element, or mouthpiece filter segment thereof, preferably has a low particle filtration efficiency.

[0221] The mouthpiece element is preferably surrounded by a plug wrap. The mouthpiece element is preferably non-ventilated so that air does not enter the aerosol-generating article along the mouthpiece element.

[0222] The mouthpiece element is preferably connected to one or more of the adjacent upstream components of the aerosol-generating article by a tipping wrapper.

[0223] The mouthpiece element preferably has an outer diameter approximately equal to the outer diameter of the aerosol-generating article. The diameter of the mouthpiece element (or mouthpiece filter segment) may be substantially the same as the outer diameter of the hollow tubular element. As discussed in this disclosure, the outer diameter of the hollow tubular element may be approximately 7.2 mm plus or minus 10 percent.

[0224] The diameter of the mouthpiece element may be about 5 mm to about 10 mm. The diameter of the mouthpiece element may be about 6 mm to about 8 mm. The diameter of the mouthpiece element may be about 7 mm to about 8 mm. The diameter of the mouthpiece element may be about 7.2 mm plus or minus 10 percent. The diameter of the mouthpiece element may be about 7.25 mm plus or minus 10 percent.

[0225] Unless otherwise specified, the resistance to draw (RTD) of a component or aerosol-generating article is measured in accordance with ISO 6565-2015. RTD refers to the pressure required to force air through the entire length of the component. The terms "pressure drop" or "draw resistance" of a component or article may also refer to "resistance to draw." These terms generally refer to measurements in accordance with ISO 6565-2015 being performed successfully under test at a temperature of about 22 degrees Celsius, a pressure of about 101 kPa (about 760 Torr), and a relative humidity of about 60%, with a volumetric flow rate of about 17.5 milliliters per second at the output or downstream end of the component being measured.

[0226] The resistance to draw (RTD) of the downstream section may be at least about 0 mmH2O. The RTD of the downstream section may be at least about 3 mmH2O. The RTD of the downstream section may be at least about 6 mmH2O.

[0227] The RTD of the downstream section may be about 12 mmH2O or less. The RTD of the downstream section may be no greater than about 11 mmH2O. The RTD of the downstream section may be about 10 mmH2O or less.

[0228] The resistance to draw (RTD) of the mouthpiece element may be at least about 0 mmH2O. The RTD of the mouthpiece element may be at least about 3 mmH2O. The RTD of the mouthpiece element may be at least about 6 mmH2O.

[0229] The RTD of the mouthpiece element may be about 12 mmH2O or less. The RTD of the mouthpiece element may be about 11 mmH2O or less. The RTD of the mouthpiece element may be about 10 mmH2O or less.

[0230] As mentioned above, the mouthpiece element or mouthpiece filter segment may be formed of a fibrous material. The mouthpiece element may be formed of a porous material. The mouthpiece element may be formed of a biodegradable material. The mouthpiece element may be formed of a cellulosic material, such as cellulose acetate. For example, the mouthpiece element may be formed of a bundle of cellulose acetate fibers having about 10 to about 15 denier per filament. For example, the mouthpiece element may be formed of a relatively low density cellulose acetate tow, such as a cellulose acetate tow containing fibers of about 12 denier per filament.

[0231] The mouthpiece element may be formed of a polylactic acid-based material. The mouthpiece element may be formed of a bioplastic material, preferably a starch-based bioplastic material. The mouthpiece element may be made by injection molding or extrusion. Bioplastic-based materials are advantageous because they can provide a simple and inexpensive mouthpiece element structure to manufacture with specific and complex cross-sectional profiles that may include multiple relatively large airflow channels extending through the material of the mouthpiece element, providing suitable RTD characteristics.

[0232] The mouthpiece elements may be formed from sheets of suitable material that are crimped, pleated, assembled, woven, or folded into elements that define a plurality of longitudinally extending channels. Such sheets of suitable material may be formed of paper, cardboard, polymers such as polylactic acid, or any other cellulosic, paper, or bioplastic-based materials. The cross-sectional profile of such mouthpiece elements may exhibit randomly oriented channels.

[0233] The mouthpiece element may be formed in any other suitable manner. For example, the mouthpiece element may be formed from a bundle of longitudinally extending tubes. The longitudinally extending tubes may be formed from polylactic acid. The mouthpiece element may be formed by extrusion, moulding, lamination, injection moulding or shredding of suitable materials. Hence, it is preferred that there is a low pressure drop (or RTD) from the upstream end of the mouthpiece element to the downstream end of the mouthpiece element.

[0234] The length of the mouthpiece element may be at least about 3 mm. The length of the mouthpiece element may be at least about 5 mm. The length of the mouthpiece element may be about 15 mm or less. The length of the mouthpiece element may be about 11 mm or less. The length of the mouthpiece element may be between about 3 mm and about 15 mm. The length of the mouthpiece element may be between about 5 mm and about 11 mm.

[0235] Preferably, the length of the mouthpiece element may be about 7mm. Preferably, the length of the mouthpiece element may be about 8mm. Preferably, the length of the mouthpiece element may be about 9mm.

[0236] The aerosol-generating article may have a total length of from about 35 millimeters to about 100 millimeters.

[0237] Preferably, the overall length of an aerosol-generating article according to the invention is at least about 35 millimeters. Preferably, the overall length of an aerosol-generating article according to the invention is at least about 38 millimeters. More preferably, the overall length of an aerosol-generating article according to the invention is at least about 40 millimeters. Even more preferably, the overall length of an aerosol-generating article according to the invention is at least about 42 millimeters.

[0238] Preferably, the overall length of an aerosol-generating article according to the invention is 70 mm or less. More preferably, the overall length of an aerosol-generating article according to the invention is 60 mm or less. Even more preferably, the overall length of an aerosol-generating article according to the invention is 50 mm or less.

[0239] The total length of the aerosol-generating article is preferably about 38 mm to about 70 mm, more preferably about 40 mm to about 70 mm, and even more preferably about 42 mm to about 70 mm. The total length of the aerosol-generating article is preferably about 38 mm to about 60 mm, more preferably about 40 mm to about 60 mm, and even more preferably about 42 mm to about 60 mm. The total length of the aerosol-generating article is preferably about 38 mm to about 50 mm, more preferably about 40 mm to about 50 mm, and even more preferably about 42 mm to about 50 mm. The total length of the aerosol-generating article may be about 45 mm.

[0240] The aerosol-generating article has an outer diameter of at least 5 millimeters. Preferably, the aerosol-generating article has an outer diameter of at least 6 millimeters. More preferably, the aerosol-generating article has an outer diameter of at least 7 millimeters.

[0241] Preferably, the aerosol-generating article has an outer diameter of about 12 millimeters or less. More preferably, the aerosol-generating article has an outer diameter of about 10 millimeters or less. Even more preferably, the aerosol-generating article has an outer diameter of about 8 millimeters or less.

[0242] The aerosol-generating article may have an outer diameter of about 5 mm to about 12 mm, preferably about 6 mm to about 12 mm, more preferably about 7 mm to about 12 mm. The aerosol-generating article may have an outer diameter of about 5 mm to about 10 mm, preferably about 6 mm to about 10 mm, more preferably about 7 mm to about 10 mm. The aerosol-generating article may have an outer diameter of about 5 mm to about 8 mm, preferably about 6 mm to about 8 mm, more preferably about 7 mm to about 8 mm.

[0243] The outer diameter of the aerosol-generating article may be substantially constant over the entire length of the article, or alternatively, different portions of the aerosol-generating article may have different outer diameters.

[0244] The aerosol-generating article according to the invention may comprise a rod of aerosol-generating substrate and a downstream section located downstream of the rod of aerosol-generating substrate. The downstream section may comprise a downstream air channelling element and a mouthpiece element. The downstream air channelling element may be located between the rod of aerosol-generating substrate and the mouthpiece element. The downstream air channelling element may be in accordance with the air channelling elements described in this disclosure. All components may be assembled in an axial, sequential and abutting manner within the wrapper of the aerosol-generating article. The aerosol-generating article may comprise a ventilation zone provided at a position along the downstream air channelling element.

[0245] The aerosol-generating article according to the invention may comprise a rod of aerosol-generating substrate and a downstream section located downstream of the rod of aerosol-generating substrate. The downstream section may comprise a downstream air channeling element and a mouthpiece element. The downstream air channeling element may be located between the rod of aerosol-generating substrate and the mouthpiece element. The downstream air channeling element may be in accordance with the air channeling elements described in this disclosure. All components may be assembled in an axial, continuous and abutting manner within the wrapper of the aerosol-generating article. The downstream section may also comprise a hollow tubular element located between the downstream air channeling element and the mouthpiece element. The aerosol-generating article may also comprise an upstream section located upstream of the rod of aerosol-generating substrate. The upstream section comprises an upstream element. The upstream element may comprise a plug element or a hollow tubular element as described in this disclosure. The aerosol-generating article may comprise a ventilation zone or a downstream air channeling element provided at a position along the hollow tubular element.

[0246] The aerosol-generating article according to the invention may comprise a rod of aerosol-generating substrate, a downstream section located downstream of the rod of aerosol-generating substrate, and an upstream section located upstream of the rod of aerosol-generating substrate. The downstream section may comprise a hollow tubular element and a mouthpiece element. The upstream section may include an upstream air channeling element. The hollow tubular element may be located between the rod of aerosol-generating substrate and the mouthpiece element. The upstream air channeling element may be in accordance with the air channeling elements described in this disclosure. All components may be assembled in an axial, continuous and abutting manner within the wrapper of the aerosol-generating article. The downstream section may also comprise a downstream air channeling element located between the rod of aerosol-generating substrate and the hollow tubular element. The aerosol-generating article may comprise a ventilation zone or downstream air channeling element provided at a position along the hollow tubular element.

[0247] The aerosol-generating article according to the invention may comprise a rod of aerosol-generating substrate, a downstream section located downstream of the rod of aerosol-generating substrate, and an upstream section located upstream of the rod of aerosol-generating substrate. The downstream section may comprise a downstream air channeling element and a mouthpiece element. The upstream section may include an upstream air channeling element. The downstream air channeling element may be located between the rod of aerosol-generating substrate and the mouthpiece element. The upstream air channeling element and the downstream air channeling element may be in accordance with the air channeling elements described in this disclosure. All components may be assembled in an axial, continuous and abutting manner within the wrapper of the aerosol-generating article. The downstream section may also comprise a hollow tubular element located between the downstream air channeling element and the mouthpiece element. The aerosol-generating article may comprise a ventilation zone or downstream air channeling element provided at a position along the hollow tubular element.

[0248] As discussed above, the present disclosure also relates to an aerosol generation system comprising an aerosol generating device having a distal end and an oral 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 an aerosol-generating article at the oral end of the device. The aerosol generating device may comprise a heating element or heater for heating the aerosol-generating substrate when the aerosol-generating article is received within the device cavity.

[0249] The device cavity may be referred to as the heating chamber of the aerosol-generating device. The device cavity may extend between a distal end and an oral (or proximal) end. The distal end of the device cavity may be a closed end and the oral (or proximal) end of the device cavity may be an open end. The aerosol-generating 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 to fit the same shape of the aerosol-generating article.

[0250] The phrase "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 phrase "an aerosol-generating article is received within a device cavity" refers to the aerosol-generating article being fully or partially received within a device cavity of the aerosol-generating article. When the aerosol-generating article is received within the device cavity, the aerosol-generating article may abut a distal end of the device cavity. When the aerosol-generating article is received within the device cavity, the aerosol-generating article may be substantially proximate to the distal end of the device cavity. The distal end of the device cavity may be defined by an end wall.

[0251] The length of the device cavity may be from about 10 mm to about 50 mm. The length of the device cavity may be from about 20 mm to about 40 mm. The length of the device cavity may be from about 25 mm to about 30 mm.

[0252] The length of the device cavity (or heating chamber) may be the same as or longer than the length of the rod of the aerosol-generating substrate. The length of the device cavity may be the same as or longer than the combined length of the upstream section or element and the rod of the aerosol-generating substrate. The length of the device cavity may be such that when an aerosol-generating article is received in the device cavity, the downstream section or a portion thereof protrudes from the device cavity. The length of the device cavity may be such that when an aerosol-generating article is received in the device cavity, a portion of the downstream section (such as a hollow tubular element or a mouthpiece element) protrudes from the device cavity. The length of the device cavity may be such that when an aerosol-generating article is received in the device cavity, a portion of the downstream section (such as a hollow tubular element or a mouthpiece element) is configured to be received in the device cavity.

[0253] At least 25 percent of the length of the downstream section may be inserted or received within the device cavity when the aerosol-generating article is received within the device.At least 30 percent of the length of the downstream section may be inserted or received within the device cavity when the aerosol-generating article is received within the device.

[0254] Optimizing the amount or length of the article inserted into the aerosol-generating device may increase resistance to inadvertent removal of the article during use. In particular, during heating of the aerosol-generating substrate, the substrate may shrink, which may reduce its outer diameter, thereby reducing the extent to which the inserted portion of the article inserted into the device can frictionally engage the device cavity. The inserted portion of the article, or the portion of the article configured to be received within the device cavity, may be the same length as the device cavity.

[0255] The length of the device cavity is preferably about 25 mm to about 29 mm. The length of the device cavity is more preferably about 26 mm to about 29 mm. Even more preferably, the length of the device cavity is about 27 mm or about 28 mm.

[0256] The combined length of the upstream section (or element) and the inserted portion of the downstream section is preferably equal to about 80 percent to about 120 percent of the length of the protruding portion of the aerosol-generating article. The downstream section or hollow tubular element or the inserted portion of the aerosol-generating article refers to the portion of the downstream section or hollow tubular element or the aerosol-generating article that is configured to be positioned within the device cavity when the aerosol-generating article is received therein. The protruding portion of the aerosol-generating article refers to the article that is configured to be positioned outside the device cavity or to protrude from the device when the aerosol-generating article is received therein. The inventors have found that such a relationship minimizes the risk of the article inadvertently slipping out of the device during use, especially after potential shrinkage of the article during use. The portion of the aerosol-generating article that is configured to be inserted into the device is preferably longer than the portion of the aerosol-generating article that is configured to protrude from the device when the aerosol-generating article is received within the aerosol-generating device.

[0257] The diameter of the device cavity may be about 4 mm to about 10 mm. The diameter of the device cavity may be about 5 mm to about 9 mm. The diameter of the device cavity may be about 6 mm to about 8 mm. The diameter of the device cavity may be about 7 mm to about 8 mm. The diameter of the device cavity may be about 7 mm to about 7.5 mm.

[0258] The diameter of the device cavity may be substantially the same as the diameter of the aerosol-generating article or may be larger. The diameter of the device cavity may be the same as the diameter of the aerosol-generating article to establish a tight fit with the aerosol-generating article.

[0259] The device cavity may be configured to establish a tight fit with an aerosol-generating article received within the device cavity. A tight fit may refer to a snug or interference fit. The aerosol-generating device may include a peripheral wall. Such a peripheral wall may define the device cavity, or the heating chamber. The peripheral wall defining the device cavity may be configured to engage in a tight fit with an aerosol-generating article received within the device cavity such that, when received within the device, there is substantially no gap or empty space between the peripheral wall defining the device cavity and the aerosol-generating article.

[0260] Such an airtight fit may establish an airtight fit or configuration between the device cavity and the aerosol-generating article received therein.

[0261] In such an airtight configuration, there will be substantially no gaps or empty spaces between the peripheral walls defining the device cavity and the aerosol-generating article for air to flow therethrough.

[0262] A tight fit with the aerosol-generating article may be established along the entire length of the device cavity or along a portion of the length of the device cavity.

[0263] The aerosol generating device may include airflow channeling extending between the channel inlet and the channel outlet. The airflow channel may be configured to establish fluid communication between an interior of the device cavity and an exterior of the aerosol generating device. The airflow channel of the aerosol generating device may be defined within a housing of the aerosol generating device to allow fluid communication between an interior of the device cavity and an exterior of the aerosol generating device. When an aerosol-generating article is received within the device cavity, the airflow channel may be configured to provide air flowing into the article to deliver the generated aerosol to a user who inhales from a mouth end of the article.

[0264] The airflow channel of the aerosol generating device may be defined within or by the peripheral wall of the housing of the aerosol generating device. In other words, the airflow channel of the aerosol generating device may be defined within the thickness of the peripheral wall, or by the inner surface of the peripheral wall, or a combination of both. The airflow channel may be partially defined by the inner surface of the peripheral wall, or partially defined within the thickness of the peripheral wall. The inner surface of the peripheral wall defines the periphery of the device cavity.

[0265] The airflow channel of the aerosol generating device may extend from an inlet located at the oral or proximal end of the aerosol generating device to an outlet located away from the oral end of the device. The airflow channel may extend along a direction parallel to the longitudinal axis of the aerosol generating device.

[0266] The heater may be any suitable type of heater, in the present invention it is preferred that the heater is an external heater.

[0267] Preferably, the heater may externally heat the aerosol-generating article when received within the aerosol-generating device. Such an external heater may surround the aerosol-generating article when inserted or received within the aerosol-generating device.

[0268] The heater may be arranged to heat the outer surface of the aerosol-generating substrate. The heater may be arranged for insertion into the aerosol-generating substrate when the aerosol-generating substrate is received within the cavity. The heater may be located within the device cavity or heating chamber.

[0269] The heater may comprise at least one heating element. The at least one heating element may be any suitable type of heating element. The device may comprise only one heating element. The device may comprise multiple heating elements. The heater may include at least one resistive heating element. The heater preferably comprises multiple resistive heating elements. The resistive heating elements are preferably electrically connected in a parallel arrangement. Advantageously, providing multiple resistive heating elements electrically connected in a parallel arrangement may facilitate delivery of desired power to the heater while reducing or minimizing the voltage required to provide the desired power. Advantageously, reducing or minimizing the voltage required to operate the heater may facilitate reducing or minimizing the physical size of the power supply.

[0270] Suitable materials for forming the at least one resistive heating element include, but are not limited to, semiconductors such as doped ceramics, "conductive" ceramics (such as, for example, molybdenum disilicide), carbon, graphite, metals, metal alloys, and composites made of ceramic and metallic materials. Such composites may include doped or undoped ceramics. Examples of suitable doped ceramics include doped silicon carbide. Examples of suitable metals include titanium, zirconium, tantalum, and platinum group metals. Examples of suitable metal alloys include stainless steel, nickel-containing, cobalt-containing, chromium-containing, aluminum-containing, titanium-containing, zirconium-containing, hafnium-containing, niobium-containing, molybdenum-containing, tantalum-containing, tungsten-containing, tin-containing, gallium-containing, manganese-containing, and iron-containing alloys, as well as nickel-, iron-, cobalt-, and stainless steel-based superalloys, Timetal®, and iron-manganese-aluminum-based alloys.

[0271] The at least one resistive heating element may include one or more stamped pieces of electrically resistive material, such as stainless steel. The at least one resistive heating element may include a heating wire or filament (e.g., Ni-Cr (nickel-chromium), platinum, tungsten, or alloy wire).

[0272] The at least one heating element may include an electrically insulating substrate and the at least one resistive heating element may be provided on the electrically insulating substrate.

[0273] The electrically insulating substrate may comprise any suitable material. For example, the electrically insulating substrate may comprise one or more of paper, glass, ceramic, anodized metal, coated metal, and polyimide. The ceramic may comprise mica, alumina (Al2O3), or zirconia (ZrO2). The electrically insulating substrate preferably has a thermal conductivity of about 40 watts per meter Kelvin or less, preferably about 20 watts per meter Kelvin or less, and ideally about 2 watts per meter Kelvin or less.

[0274] The heater may comprise a heating element comprising a rigid, electrically insulating substrate having one or more conductive tracks or wires disposed on its surface. The size and shape of the electrically insulating substrate may allow the heater to be inserted directly into the aerosol-generating substrate. If the electrically insulating substrate is not sufficiently rigid, the heating element may comprise further reinforcing means. An electric current may be passed through the one or more conductive tracks to heat the heating element and the aerosol-generating substrate.

[0275] The heater may include an induction heating arrangement. The induction heating arrangement may comprise an inductor coil and a power source configured to provide a high frequency oscillating current to the inductor coil. As used herein, high frequency oscillating current means an oscillating current having a frequency of about 500 kHz to about 30 MHz. The heater may advantageously comprise a DC / AC inverter for converting a DC current provided by a DC power source to an alternating current. The inductor coil may be arranged to generate a high frequency oscillating electromagnetic field upon receiving the high frequency oscillating current from the power source. The inductor coil may be arranged to generate a high frequency oscillating electromagnetic field within the device cavity. The inductor coil may substantially surround the device cavity. The inductor coil may extend at least partially along a length of the device cavity.

[0276] The heater may include an induction heating element. The induction heating element may be a susceptor element. As used herein, the term "susceptor element" refers to an element that includes a material capable of converting electromagnetic energy into heat. When the susceptor element is located within an alternating electromagnetic field, the susceptor is heated. Heating of the susceptor element may be the result of at least one of hysteresis losses and eddy currents induced in the susceptor, depending on the electrical and magnetic properties of the susceptor material.

[0277] The susceptor element may be arranged such that when an aerosol-generating article is received within the cavity of the aerosol generating device, the oscillating electromagnetic field generated by the inductor coil induces a current in the susceptor element, heating the susceptor element. The aerosol generating device is preferably capable of generating a fluctuating electromagnetic field having a magnetic field strength (H-field strength) of 1-5 kiloamperes per meter (kA / m), preferably 2-3 kA / m, for example about 2.5 kA / m. The electrically operated aerosol generating device is preferably capable of generating a fluctuating electromagnetic field having a frequency of 1-30 MHz, for example 1-10 MHz, for example 5-7 MHz.

[0278] The aerosol-generating article may comprise a susceptor element, which is preferably positioned in contact with the aerosol-generating substrate.

[0279] The susceptor element may be located within the aerosol-generating apparatus. The susceptor element may be located within the cavity. The aerosol-generating apparatus may include only one susceptor element. The aerosol-generating apparatus may comprise multiple susceptor elements. The susceptor element is preferably arranged to heat an outer surface of the aerosol-generating substrate.

[0280] The susceptor element may comprise any suitable material. The susceptor element may be formed from any material that can be inductively heated to a temperature sufficient to release volatile compounds from the aerosol-generating substrate. Suitable materials for the elongated susceptor element include graphite, molybdenum, silicon carbide, stainless steel, niobium, aluminum, nickel, nickel-containing compounds, titanium, and composites of metallic materials. Some susceptor elements include metal or carbon. Advantageously, the susceptor element may include or consist of a ferromagnetic material, such as ferritic iron, ferromagnetic steel or stainless steel, ferromagnetic particles, and ferrites. A suitable susceptor element may be or include aluminum. The susceptor element preferably includes more than about 5 percent, preferably more than about 20 percent, more preferably more than about 50 percent or more than about 90 percent of ferromagnetic or paramagnetic material. Some elongated susceptor elements may be heated to a temperature of more than about 250 degrees Celsius.

[0281] The susceptor element may comprise a non-metallic core having a metallic layer disposed thereon. For example, the susceptor element may include a ceramic core or a metallic track formed on the outer surface of the substrate.

[0282] The aerosol generating device may comprise at least one resistive heating element and at least one inductive heating element.The aerosol generating device may comprise a combination of resistive and inductive heating elements.

[0283] In use, the heater can be controlled to operate within a defined operating temperature range that is less than the maximum operating temperature. The operating temperature range within the heating chamber (or device cavity) is preferably from about 150 degrees Celsius to about 300 degrees Celsius. The operating temperature range of the heater may be from about 150 degrees Celsius to about 250 degrees Celsius.

[0284] Preferably, the operating temperature range of the heater may be between about 150 degrees Celsius and about 200 degrees Celsius. More preferably, the operating temperature range of the heater may be between about 180 degrees Celsius and about 200 degrees Celsius. Specifically, as described herein, it has been found that optimal and consistent aerosol delivery may be achieved when using an aerosol generating device having an external heater with an operating temperature range of about 180 degrees Celsius to about 200 degrees Celsius with an aerosol-generating article having a relatively low RTD (e.g., having an RTD of the downstream section less than 15 mmH2O).

[0285] In embodiments in which the aerosol-generating article comprises a ventilation zone, the ventilation zone may be positioned such that it is exposed when the aerosol-generating article is received within the device cavity. Thus, the length of the device cavity or heating chamber may be less than the distance from the upstream end of the aerosol-generating article to the ventilation zone located along the downstream section. In other words, when the aerosol-generating article is received within the aerosol-generating device, the distance between the ventilation zone and the upstream end of the upstream element may be greater than the length of the heating chamber.

[0286] When the article is received within the device cavity, the ventilation zone may be located at least 0.5 mm away (in the downstream direction of the article) from the mouth end (or mouth end face) of the device cavity or the device itself. When the article is received within the device cavity, the ventilation zone may be located at least 1 mm away (in the downstream direction of the article) from the mouth end (or mouth end face) of the device cavity or the device itself. When the article is received within the device cavity, the ventilation zone may be located at least 2 mm away (in the downstream direction of the article) from the mouth end (or mouth end face) of the device cavity or the device itself.

[0287] The ratio between the distance between the ventilation zone and the upstream end of the upstream element and the length of the heating chamber is preferably from about 1.03 to about 1.13.

[0288] Such positioning of the ventilation zone ensures that the ventilation zone is not blocked within the device cavity itself, while also minimizing the risk of blockage by the user's lips or hands, as the ventilation zone is located as far upstream from the downstream end of the article as is reasonably possible without becoming blocked within the device cavity.

[0289] The aerosol generating device may include a power source. The power source may be a DC power source. The power source may be a battery. The power source may be a nickel metal hydride battery, a nickel cadmium battery, or a lithium-based battery (e.g., lithium cobalt, lithium iron phosphate, or lithium polymer battery). However, in some embodiments, the power source may be another form of charge storage device, such as a capacitor. The power source may be rechargeable and may have a capacity that allows for the storage of sufficient energy for one or more user operations, such as, for example, one or more aerosol generating experiences. For example, the power source may have a capacity sufficient to allow continuous heating of the aerosol-generating substrate for approximately six minutes, or a multiple of six minutes, corresponding to the typical time it takes to smoke one conventional cigarette. In another example, the power source may have a capacity sufficient to allow for a predetermined number of puffs, or for discontinuous activation of the heater.

[0290] [Example] The following provides a non-exhaustive list of non-limiting examples, any one or more of the features of which may be combined with any one or more features of another example, embodiment, or aspect described herein.

[0291] Example 1. An aerosol-generating article comprising a rod of aerosol-generating substrate and a downstream section provided downstream of the rod of aerosol-generating substrate. Example 2. An aerosol-generating article as described in example 1, wherein the downstream section comprises an air channeling element abutting the rod of the aerosol-generating substrate, preferably abutting the downstream end of the rod of the aerosol-generating substrate. Example 3. The aerosol-generating article of example 2, wherein the air channeling element of the downstream section is a downstream air channeling element. Example 4. An aerosol-generating article as described in any one of Examples 1 to 3, further comprising an upstream section located upstream of the rod of the aerosol-generating substrate, the upstream section comprising at least one upstream element. Example 5. The aerosol-generating article of example 4, wherein the at least one upstream element comprises an upstream air channeling element. Example 6. The aerosol-generating article of example 4 or example 5, wherein the upstream end of the upstream element defines the upstream end of the aerosol-generating article. Example 7. The aerosol-generating article of Example 1, further comprising an upstream section located upstream of the rod of the aerosol-generating substrate and a downstream section located downstream of the rod of the aerosol-generating substrate, wherein the upstream section comprises an upstream air channeling element abutting the upstream end of the rod of the aerosol-generating substrate, and the downstream section comprises a downstream air channeling element abutting the downstream end of the rod of the aerosol-generating substrate. Example 8. An aerosol-generating article according to any one of Examples 1 to 7, wherein the air channelling element comprises at least one outer air passage, which may define an internal air passage or an outer air passage. Example 9. An aerosol-generating article as described in any of Examples 1-8, wherein the air channeling element comprises a groove defined on an outer surface of the body of the air channeling element, the groove defining an outer air passageway extending from an upstream end of the air channeling element to a downstream end of the air channeling element. Example 10. An aerosol-generating article as described in any one of Examples 1 to 9, wherein the body of the air channeling element comprises a core portion and a peripheral portion in which at least one groove is defined, and the core portion is substantially solid. Example 11. An aerosol-generating article according to any one of Examples 1 to 10, wherein the air channeling element does not define an internal cavity. Example 12. An aerosol-generating article as described in any of Examples 1 to 11, wherein the air channeling element comprises a body having a core portion and a peripheral portion, the core portion comprising one or more inner air passages, and the peripheral portion comprising one or more outer air passages, and a total cross-sectional area of ​​the one or more outer air passages is greater than a total cross-sectional area of ​​the one or more inner air passages. Example 13. 13. An aerosol-generating article according to any one of Examples 1 to 12, wherein the ratio of the total cross-sectional area of ​​the one or more outer air passages to the total cross-sectional area of ​​the one or more inner air passages is at least 2. Example 14. 14. An aerosol-generating article according to any one of Examples 1 to 13, wherein the ratio of the total cross-sectional area of ​​the one or more outer air passages to the total cross-sectional area of ​​the one or more inner air passages is at least 3. Example 15. 15. An aerosol-generating article according to any one of Examples 1 to 14, wherein the ratio of the total cross-sectional area of ​​the one or more inner air passages to the total cross-sectional area of ​​the one or more outer air passages is 10 or less. Example 16. 16. An aerosol-generating article according to any one of Examples 1 to 15, wherein the one or more outer air passages comprises at least four outer air passages. Example 17. An aerosol-generating article according to any of Examples 1-16, wherein each outer air passage is defined by a groove provided on the outer surface of the or each air channeling element. Example 18. An aerosol-generating article as described in any of Examples 1-17, wherein each outer air passage is defined by an internal cavity or air channeling extending along the or each air channeling element. Example 19. An aerosol-generating article as described in any of Examples 1-18, wherein the ratio of the total cross-sectional area of ​​the one or more outer air passages to the total cross-sectional area of ​​the air channeling element is at least about 30 percent. Example 20. An aerosol-generating article as described in any of Examples 1 to 19, further comprising a mouthpiece element provided downstream of the rod of the aerosol-generating substrate, wherein the air channelling element is located upstream of the rod of the aerosol-generating substrate or between the rod of the aerosol-generating substrate and the mouthpiece element. Example 21. An aerosol-generating article as described in any of Examples 1 to 20, further comprising a mouthpiece element provided downstream of the rod of the aerosol-generating substrate, wherein the upstream air channelling element is located upstream of the rod of the aerosol-generating substrate, or the downstream air channelling element is located between the rod of the aerosol-generating substrate and the mouthpiece element. Example 22. An aerosol-generating article as described in any of Examples 1 to 21, further comprising a hollow tubular element provided downstream of the rod of the aerosol-generating substrate, and an air channeling element located upstream of the rod of the aerosol-generating substrate or between the rod of the aerosol-generating substrate and the hollow tubular element. Example 23. An aerosol-generating article as described in any of Examples 1 to 22, further comprising a hollow tubular element provided downstream of the rod of the aerosol-generating substrate, wherein the upstream air channeling element is located upstream of the rod of the aerosol-generating substrate or the downstream air channeling element is located between the rod of the aerosol-generating substrate and the hollow tubular element. Example 24. An aerosol-generating article according to any one of Examples 1-23, wherein the or each air channeling element is substantially impermeable. Example 25. An aerosol-generating article according to any of Examples 1-24, wherein the or each air channeling element is formed by thermoforming. Example 26. An aerosol-generating article as described in any one of Examples 1 to 25, wherein the grooves have a depth of at least 0.5 mm. Example 27. An aerosol-generating article as claimed in any one of Examples 1 to 26, wherein the groove has a depth of 2 mm or less. Example 28. 28. An aerosol-generating article according to any of Examples 1-27, wherein the or each air channeling element comprises at least four grooves. Example 29. An aerosol-generating article as described in any one of Examples 1 to 28, wherein the groove follows a helical or corrugated path. Example 30. An aerosol-generating article as described in any of Examples 1 to 29, further comprising a wrapper surrounding the or each air channeling element, the wrapper covering the exterior air passage defined by the grooves such that the wrapper defines a boundary of the exterior air passage. Example 31. The aerosol-generating article of any one of Examples 1 to 30, further comprising a ventilation zone. Example 32. 32. The aerosol-generating article of example 31, wherein a ventilation zone is provided at a location along the hollow tubular element in the downstream section. Example 33. An aerosol-generating article as claimed in any one of Examples 1 to 32, wherein the rod of the aerosol-generating substrate has a length of from 8 mm to 16 mm. Example 34. 34. An aerosol-generating article as claimed in any one of Examples 1 to 33, wherein the rod of the aerosol-generating substrate has a resistance to withdrawal (RTD) of between 4 mmH2O and 10 mmH2O. Example 35. An aerosol-generating article as claimed in any one of Examples 1 to 34, wherein the aerosol-generating substrate comprises tobacco cut material. Example 36. 36. The aerosol-generating article of Example 35, wherein the cut tobacco material has an average density of 150 milligrams per cubic centimeter to 500 milligrams per cubic centimeter. Example 37. 37. The aerosol-generating article of any one of Examples 1 to 36, wherein the aerosol-generating substrate comprises one or more aerosol-forming bodies, and the content of the aerosol-forming bodies in the aerosol-generating substrate is 10 weight percent to 20 weight percent on a dry weight basis. Example 38. 38. The aerosol-generating article of example 37, wherein the aerosol former comprises one or more of glycerin and propylene glycol. Example 39. An aerosol-generating article as claimed in any one of Examples 1 to 38, wherein the aerosol-generating substrate comprises a tobacco cut filler. Example 40. An aerosol-generating article according to any one of Examples 1 to 39, wherein the outer diameter of the article is substantially uniform along its length. Example 41. An aerosol generating system comprising an aerosol generating article described in any one of Examples 1 to 40, and an aerosol generating device comprising a heating chamber for receiving the aerosol generating article and at least a heating element provided around or around the heating chamber.

[0292] The invention will now be further described with reference to the drawings of the accompanying drawings, in which:

[0293] Figure 1a shows an aerosol-generating article 10 comprising a rod of aerosol-generating substrate 12 and a downstream section located downstream of the rod of aerosol-generating substrate 12. The aerosol-generating article 10 extends from an upstream or distal end 16 to a downstream or oral end 18 which coincides with the downstream end of the downstream section. As shown in Figure 1a, the downstream section comprises a downstream air channelling element 11 and a mouthpiece element 8. The aerosol-generating articles described herein are assembled together using one or more wrappers, not shown.

[0294] The aerosol-generating article 10 has an outer diameter of about 7.2 mm. The length of the aerosol-generating substrate 12 is about 8 mm.

[0295] The aerosol-generating substrate rod 12 comprises shredded tobacco material. The aerosol-generating substrate rod 12 comprises 150 milligrams of shredded tobacco material containing 13 weight percent to 16 weight percent glycerin. The density of the aerosol-generating substrate is approximately 300 mg per cubic centimeter. The aerosol-generating substrate rod 12 has an RTD of approximately 6 to 8 mmH2O. The aerosol-generating substrate rods 12 are individually wrapped with plug wrap (not shown).

[0296] The downstream air channelling element 11 is located immediately downstream of the rod 12 of the aerosol-generating substrate, and the downstream air channelling element 11 is longitudinally aligned with the rod 12. The upstream end of the downstream air channelling element 11 abuts the downstream end of the rod 12 of the aerosol-generating substrate.

[0297] The exterior air passages for air and aerosol travel therethrough are present in the form of grooves 5 provided around the exterior surface of the air channelling element 11. The air channelling element 11 comprises six grooves 5 extending longitudinally along the body of the air channelling element 11.

[0298] The length of the downstream air channelling element 11 is approximately 12 mm.

[0299] The mouthpiece element 8 extends from the downstream end of the air channeling element 11 to the downstream or mouth end of the aerosol-generating article 10. The mouthpiece element 8 has a length of about 7 mm. The outer diameter of the mouthpiece element 8 is about 7.2 mm. The mouthpiece element 8 comprises a low density cellulose acetate filter segment. The RTD of the mouthpiece element 8 is about 8 mmH2O. The mouthpiece element 8 may be individually wrapped with a plug wrap (not shown).

[0300] 1b illustrates the aerosol-generating article 10 assembled within a wrapper 52 that surrounds the components of the article 10. An outer air passageway is defined between the groove 5 and the inner surface of the wrapper 52.

[0301] 2 illustrates an aerosol-generating article 10a similar to the aerosol-generating article 10, but with a ventilation zone 13 provided at a location along the air channeling element 11. More specifically, the ventilation zone 13 is provided approximately 16 millimeters from the downstream end 18 of the article 10. The ventilation zone 13 comprises a circumferential row of openings or perforations surrounding the air channeling element 11. The perforations in the ventilation zone 13 allow for ingress of fluid from the exterior of the article 10 into the grooves 5. Any of the other embodiments described herein may also have a ventilation zone that provides fluid communication between the exterior of the article 10 and any outer air passages (including grooves) defined in the air channeling element.

[0302] 3 illustrates an aerosol-generating article 20 similar to the aerosol-generating article 10, but with a hollow tubular element 14 instead of the downstream air channeling element 11, and an upstream section upstream of the rod 12 of the aerosol-generating substrate including an upstream air channeling element 15. Similar to the downstream air channeling element 11, the upstream air channeling element 15 (or the upstream plug or front plug) comprises an outer air passage for air to move in the form of grooves 5 provided around the outer surface of the air channeling element 15. The air channeling element 15 also comprises six grooves 5 extending longitudinally along the body of the air channeling element 15. The hollow tubular element 14 is provided between the rod 12 of the aerosol-generating substrate and the mouthpiece element 8. The upstream air channeling element 15 has a length of about 5 mm. The hollow tubular element 14 may have a length of about 10 mm.

[0303] FIG. 4 illustrates an aerosol-generating article 30 that is similar to aerosol-generating article 10, but further comprises an upstream section upstream of the rod 12 of aerosol-generating substrate that comprises an upstream air channeling element 15, as described above.

[0304] Figures 5a and 5b show cross-sections of an embodiment of an air channeling element 11, 15. As shown in Figure 5b, in addition to the six grooves 5, the air channeling element 11, 15 may further comprise an inner central air passage 7 that extends through a core portion of the body of the air channeling element 11, 15. The grooves 5 have a depth of about 1.5 mm. The body of the air channeling element 11, 15 has an outer diameter of about 7.2 mm. The inner air passage 7 shown in Figure 5b has a circular cross-section and a diameter of about 1 mm.

[0305] Figures 6a and 6b show cross-sections of an embodiment of an air channeling element 11, 15 having four grooves 5. In addition to the four grooves 5 defined on the peripheral portion P of the body of the air channeling element 11, 15, the air channeling element 11, 15 may further comprise an inner air passage 7 extending through a core portion C of the body of the air channeling element 11, 15. The grooves 5 have a depth H of about 1.5 mm. The body of the air channeling element 11, 15 has an outer diameter D of about 7.2 mm. The inner air passage 7 shown in Figure 6b has a circular cross-section and a diameter of about 1 mm.

[0306] Figure 7a depicts an aerosol generating system 1 comprising an exemplary aerosol generating device 100 (only a portion of which is shown for ease of reference) and an aerosol generating article 10 according to the embodiment shown in Figures la and lb. Any embodiment of the aerosol generating article according to the present disclosure may be used.

[0307] 7a illustrates a downstream oral end portion of an aerosol generating device 100 in which a device cavity or heating chamber is defined and in which an aerosol-generating article 10 can be received. The aerosol generating device 1 comprises a housing 24 extending between an oral end and a distal end (not shown). The housing 24 comprises a peripheral wall 26. The peripheral wall 26 defines a device cavity for receiving the aerosol-generating article 10. The device cavity is defined by a closed distal end and an open oral end. The oral end of the device cavity is located at the oral end of the aerosol generating device 1. The aerosol-generating article 10 is configured to be received through the oral end of the device cavity (or heating chamber) and configured to abut the distal closed end of the device cavity.

[0308] A device airflow intake 22 is defined at the distal end of the device cavity. Air may enter the aerosol-generating substrate 12 via the airflow intake 22, ensuring fluid communication between the exterior of the device 1 and the rod 12 of the aerosol-generating substrate.

[0309] The aerosol generating device 1 further comprises an external heater 28, and a power supply (not shown) for supplying power to the heater 28. A controller (not shown) is also provided for controlling the supply of such power to the heater 28. The heater 28 is configured to controllably heat the aerosol-generating article 10 during use when the aerosol-generating article 10 is received within the device 1. The heater 28 is in the form of a heater tube and is arranged to externally heat the aerosol-generating substrate 12.

[0310] 7b and 7c show how aerosol is drawn from the peripheral portion PS of the rod 12 of the aerosol-generating substrate during the initial heating stage. As shown in FIG. 7b, as the aerosol-generating substrate 12 heats up, aerosol is drawn primarily from the peripheral portion PS of the substrate 12. The long dashed dotted line B shows an imaginary boundary between the peripheral portion PS of the substrate 12 and the core portion CS of the substrate 12, which may take longer to heat and generate aerosol after the start of the heating cycle. The downstream air channeling element 11 advantageously facilitates the aerosol from the peripheral portion PS of the substrate 12 to be drawn through the outer air passage defined by the grooves 5, thereby accelerating the generation and delivery of consumable aerosol to a further downstream user. As shown in FIG. 7c, by the downstream air channeling element having a central inner air passage 7, aerosol originating primarily from the core portion CS of the substrate 12 may also be drawn through the inner air passage 7.

[0311] For the purposes of this specification and the appended claims, unless otherwise indicated, all numbers expressing amounts, quantities, percentages, and the like, should be understood in all cases as modified 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 recited herein. Thus, in this context, the number A is understood as A±10%. Within this context, the number A may be considered to include a numerical value that is within the general standard error for the measurement of the property that the number A modifies. The number A may deviate by the percentages recited above, in some cases as used in the appended claims, provided that the amount by which A deviates does not materially affect the basic and novel property(ies) 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 recited herein.

Claims

1. 1. An aerosol generation system comprising an aerosol-generating article for producing an inhalable aerosol upon heating, and an aerosol-generating device comprising a heating chamber, the aerosol-generating article being configured to be received within the heating chamber; a rod of an aerosol-generating substrate; an air channeling element abutting the rod of the aerosol-generating substrate, the air channeling element having a groove defined on an outer surface thereof, the groove defining an external air passageway extending from an upstream end of the air channeling element to a downstream end of the air channeling element; An aerosol-generating system, wherein the aerosol-generating device comprises an external heater configured to externally heat the rod of the aerosol-generating substrate.

2. An aerosol generating system as described in claim 1, wherein the aerosol generating article further comprises a downstream section located downstream of the rod of the aerosol generating substrate, the downstream section comprising the air channeling element abutting the downstream end of the rod of the aerosol generating substrate.

3. An aerosol generating system as described in claim 1 or 2, wherein the aerosol generating article further comprises a ventilation zone located along the air channeling element.

4. An aerosol generating system as described in claim 1, wherein the aerosol generating article further comprises an upstream section located upstream of the rod of the aerosol generating substrate, the upstream section comprising the air channeling element abutting the upstream end of the rod of the aerosol generating substrate.

5. An aerosol generating system as described in claim 1, wherein the aerosol generating article further comprises an upstream section located upstream of the rod of the aerosol generating substrate and a downstream section located downstream of the rod of the aerosol generating substrate, the upstream section comprising an air channeling element abutting the upstream end of the rod of the aerosol generating substrate, and the downstream section comprising a downstream air channeling element abutting the downstream end of the rod of the aerosol generating substrate.

6. An aerosol generating system as described in claim 1 or 2, wherein the aerosol generating article further comprises a mouthpiece element provided downstream of the rod of the aerosol generating substrate, and the air channeling element is located upstream of the rod of the aerosol generating substrate or between the rod of the aerosol generating substrate and the mouthpiece element.

7. An aerosol generating system as described in claim 1 or 2, wherein the aerosol generating article further comprises a hollow tubular element provided downstream of the rod of the aerosol generating substrate, and the air channeling element is located upstream of the rod of the aerosol generating substrate or between the rod of the aerosol generating substrate and the hollow tubular element.

8. 3. The aerosol generating system of claim 1, wherein the body of the air channeling element comprises a core portion and a peripheral portion in which at least one groove is defined, the core portion being substantially solid.

9. 3. The aerosol generating system of claim 1, wherein the air channeling element does not define an internal cavity.

10. 3. The aerosol generating system of claim 1, wherein the air channeling element is formed by thermoforming.

11. 3. The aerosol generating system of claim 1, wherein the grooves have a depth of at least 0.5 mm.

12. 3. The aerosol generating system of claim 1, wherein the grooves have a depth of 2 mm or less.

13. 3. The aerosol generating system of claim 1, wherein the air channeling element comprises at least four grooves.

14. 3. The aerosol generating system of claim 1, wherein the grooves follow a spiral or wave-like path on the air channeling element.

15. An aerosol generating system as described in claim 1 or 2, wherein the aerosol generating article further comprises a wrapper surrounding the air channeling element, the wrapper covering the external air passage defined by the groove such that the wrapper defines the boundary of the external air passage.

Images