Aerosol generating article having a non-homogenized tobacco substrate

Abstract

The aerosol-generating article (10) for generating an inhalable aerosol upon heating includes a rod-shaped aerosol-generating element (12) extending from a mouth end to a distal end and including an aerosol-generating substrate, the aerosol-generating substrate including an aerosol former, and a downstream section (14) located downstream of the aerosol-generating element, the downstream section extending from the downstream end of the aerosol-generating element (10) to the mouth end of the aerosol-generating article (10). The downstream section includes a hollow tubular element (20). The aerosol-generating element has a length-to-diameter ratio of about 0.5 to about 3.0. The aerosol-generating substrate includes a tobacco cut filler, and the aerosol-former content in the aerosol-generating substrate is at least 8 weight percent.

Description

[Technical Field]

[0001] The present invention relates to an aerosol generating article comprising an aerosol generating substrate and adapted to generate an inhalable aerosol upon heating. [Background 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, aerosols are generated by transferring heat from a heat source to a physically separated aerosol-generating substrate or material, which may be in contact with, within, around, or downstream of the heat source. During use of the aerosol-generating article, volatile compounds are released from the aerosol-generating substrate by heat transfer from the heat source and 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 generators for consuming aerosol-generating articles. Such devices include, for example, electrically heated aerosol generators in which aerosols are generated by heat transfer from one or more electric heater elements of the aerosol generator to an aerosol-generating substrate of a heated aerosol-generating article. For example, electrically heated aerosol generators have been proposed that include internal heater blades adapted to be inserted into an aerosol-generating substrate. As an alternative, WO2015 / 176898 proposes an inductively exothermic aerosol-generating article comprising an aerosol-generating substrate and a susceptor disposed within the aerosol-generating substrate. Further alternatives are described in WO2020 / 115151, which discloses one or more aerosol-generating articles to be used in combination with an external heating system comprising one or more heating elements disposed around the outer surface of the aerosol-generating article. For example, the external heating elements may be provided in the form of flexible heating foils on a dielectric substrate such as polyimide.

[0004] Aerosol-generating articles in which the tobacco-containing substrate is heated rather than burned present several challenges not encountered with conventional smoking articles. Firstly, the tobacco-containing substrate is typically heated to significantly lower temperatures compared to the temperature reached by the pre-burning portion of a conventional cigarette. This can affect nicotine release from the tobacco-containing substrate and nicotine delivery to the consumer. At the same time, if the heating temperature is increased in an attempt to promote nicotine delivery, the resulting aerosol typically needs to be cooled more extensively and rapidly before reaching the consumer. However, technical solutions commonly used to cool mainstream smoke in conventional smoking articles, such as providing a highly filtration-efficient segment at the mouth-end of the cigarette, may have undesirable effects in aerosol-generating articles in which the tobacco-containing substrate is heated rather than burned, as this can reduce nicotine delivery.

[0005] Many aerosol generating articles have been proposed to address one or more of the challenges associated with heating, in particular, rather than combustion of the aerosol generating substrate, in which multiple elements are combined with an aerosol generating element comprising an aerosol generating substrate, for example, aligned longitudinally. As an example, the aerosol generating element is combined with a support element that provides improved structural strength to the article, an aerosol cooling element configured to lower the temperature of the aerosol, a low-filtration mouthpiece element, and so on.

[0006] In general, there is a need for aerosol generating articles that are easy to use and have improved practicality. Furthermore, it would be desirable to provide aerosol generating articles that are easier to manufacture and make the entire production chain more sustainable and cost-effective. There is also a need for aerosol generating articles that are particularly suitable for use in combination with external heating systems, and in particular, aerosol generating articles with improved aerosol generation and aerosol-forming material delivery.

[0007] Therefore, it would be desirable to provide a novel and improved aerosol-generating article configured to satisfy at least one of the above-mentioned needs. Furthermore, it would be desirable to provide an aerosol-generating article that can be manufactured efficiently and quickly, and preferably has sufficiently low RTD variation between products. [Overview of the project]

[0008] This disclosure relates to an aerosol generating article for generating an inhalable aerosol upon heating, the aerosol generating article extending from a mouth end to a distal end and comprising an aerosol generating element. The aerosol generating element may be in the form of a rod. The aerosol generating element may comprise an aerosol generating substrate, the aerosol generating substrate comprising an aerosol forming body. Furthermore, the aerosol generating article may comprise a downstream section located downstream of the aerosol generating element. The downstream section may extend from the downstream end of the aerosol generating element to the mouth end of the aerosol generating article. The downstream section may comprise a hollow tubular element. The ratio of the length to the diameter of the aerosol generating element may be about 0.5 to about 3.0. The aerosol generating substrate may comprise a tobacco cut filler. The aerosol forming body content in the aerosol generating substrate may be at least about 8 weight percent.

[0009] The present invention provides an aerosol generating article for generating an inhalable aerosol when heated, comprising an aerosol generating element extending from the mouth end to the distal end and containing an aerosol generating substrate, wherein the aerosol generating substrate contains an aerosol forming body, and a downstream section located downstream of the aerosol generating element. The downstream section comprises a hollow tubular element. The ratio of the length to the diameter of the aerosol generating element is about 0.5 to about 3.0. The aerosol generating substrate contains a tobacco cut filler. The aerosol forming body content in the aerosol generating substrate is at least about 8 weight percent.

[0010] The aerosol generating article according to the present invention therefore provides a novel configuration of a section of an aerosol generating element, characterized by a combination of a tobacco cut filler and an aerosol generating substrate comprising at least about 8 wt% aerosol forming material, with a specific shape defined by a length-to-diameter ratio in the range of about 0.5 to about 3.0. This is further combined with a hollow element located downstream of the aerosol generating element to contribute to limiting the RTD downstream of the aerosol generating substrate.

[0011] The inventors have found that an aerosol-generating article having an aerosol-generating element having the above-described shape and a content of aerosol-forming material within the above-defined range can advantageously optimize the delivery of aerosols to consumers, particularly when the article is used in combination with an external heating system.

[0012] This is desirable because it simplifies the structure and operation of both the aerosol generating article and the heating device. Furthermore, it has been found that this makes it possible to heat the substrate to a lower temperature without compromising the quality and quantity of aerosols delivered to the consumer. By adjusting the characteristics of the cut filler and aerosol content within the aerosol generating element, heat transfer through the aerosol generating element can also be controlled precisely and effectively.

[0013] Furthermore, the provision of a downstream section containing a hollow tubular element has the effect that the majority of the overall RTD of the aerosol-generating article is provided by the aerosol-generating element itself. Therefore, it is possible to fine-tune the RTD of the aerosol-generating element itself, and consequently the RTD of the entire aerosol-generating article, by adjusting the properties of the cut filler, such as particle size, particle size distribution, and packing density.

[0014] Furthermore, by providing a hollow element downstream of the aerosol generating rod, a substantially empty volume is provided within the article at a location downstream of the aerosol generating element. In this substantially empty volume, nucleation and growth of aerosol particles are promoted. This can further contribute to improved aerosol generation and delivery compared to existing articles.

[0015] For the purposes of this specification and the appended claims, unless otherwise indicated, all numbers representing amounts, quantities, percentages, etc., should be understood in all cases as being modified by the term “approximately.” Furthermore, all ranges include the disclosed maximum and minimum points and any intermediate ranges therebetween, which may or may not be specifically listed herein. Thus, in this context, the number A is understood as A ± 10%. In this context, the number A may be considered to include a number that falls within the general standard error to the measurement of the characteristic that the number A modifies. In some cases as used in the appended claims, the number A may deviate by the percentages listed above, provided that the amount of deviation does not substantially affect the basic and novel characteristics of the claimed invention. Furthermore, all ranges include the disclosed maximum and minimum points and any intermediate ranges therebetween, which may or may not be specifically listed herein.

[0016] According to the present invention, an aerosol generating article is provided for generating an inhalable aerosol upon heating. The aerosol generating article comprises an element having an aerosol generating substrate.

[0017] The term "aerosol-generating article" is used herein to mean an article in which an aerosol-generating substrate is heated to produce an inhalable aerosol that is delivered to the consumer. The term "aerosol-generating substrate" as used herein means a substrate having the ability to generate an aerosol by releasing volatile compounds upon heating.

[0018] Conventional cigarettes are ignited when the user lights a flame at one end of the cigarette and inhales air through the other end. The localized heat from the flame and the oxygen in the air drawn in through the cigarette ignites the end of the cigarette, and the resulting combustion produces inhalable smoke. In contrast, in heated aerosol generating articles, the aerosol is generated by heating a flavor-generating substrate (such as tobacco). Known heated aerosol generating articles include, for example, electrically heated aerosol generating articles and aerosol generating articles in which an aerosol is generated by the transfer of heat from a combustible fuel element or heat source to a physically separated aerosol-forming material. For example, the aerosol generating article according to the present invention has a particular application in an aerosol generating system comprising an electrically heated aerosol generating device having an internal heater blade adapted to be inserted into a rod of an aerosol generating substrate. This type of aerosol generating article is based on prior art, e.g., EP0822 76 It is listed in 0.

[0019] As used herein, the term "aerosol generator" refers to a device comprising a heater element that interacts with an aerosol-generating substrate of an aerosol-generating article to generate an aerosol.

[0020] The aerosol generating element may comprise an aerosol generating substrate or be in the form of a rod made therefrom. As used herein in connection with the present invention, the term “rod” is used to refer to a generally cylindrical element having a substantially circular, oval, or elliptical cross-section.

[0021] As used herein, the term “longitudinal direction” refers to the direction corresponding to the main longitudinal axis of the aerosol generating article, extending between the upstream and downstream ends of the aerosol generating article. As used herein, the terms “upstream” and “downstream” describe the relative position of an element (or part of an element) of the aerosol generating article with respect to the direction in which aerosols are transported through the aerosol generating article during use.

[0022] In use, air is drawn longitudinally through the aerosol-generating article. The term "transverse direction" refers to a direction perpendicular to the longitudinal axis. Any reference to a "cross-section" of an aerosol-generating article or a component of an aerosol-generating article refers to a transverse cross-section, unless otherwise stated.

[0023] The term "length" means the dimension of a component of the aerosol-generating article in the longitudinal direction. For example, it may be used to mean the dimension of a rod or an elongate tubular element in the longitudinal direction.

[0024] The aerosol-generating article further comprises a downstream section at a position downstream of the rod of aerosol-generating substrate. As will become apparent from the following description of different embodiments of the aerosol-generating article of the present invention, the downstream section may comprise one or more downstream elements.

[0025] In some embodiments, the downstream section may comprise a hollow section between the mouth end of the aerosol-generating article and the aerosol-generating element. The hollow section may comprise a hollow tubular element.

[0026] As used herein, the term "hollow tubular segment" or "hollow tubular element" refers to a generally elongate element that defines a cavity or airflow passage along its longitudinal axis. In particular, the term "tubular" is used hereinafter in reference to an element or segment that has a substantially cylindrical cross-section and defines at least one airflow conduit establishing uninterrupted fluid communication between the upstream end of the tubular element or segment and the downstream end of the tubular element or segment. However, it will be appreciated that alternative shapes for the tubular element or segment (for example, alternative cross-sectional shapes) may in some cases be possible.

[0027] In the context of the present invention, a hollow tubular segment or hollow tubular element provides an unrestricted flow path. This means that a hollow tubular segment or hollow tubular element provides a negligible level of drawdown resistance (RTD). The term "negligible level of RTD" is used to describe an RTD of less than 1 mmH2O per 10 mm length hollow tubular segment or hollow tubular element, preferably less than 0.4 mmH2O per 10 mm length hollow tubular segment or hollow tubular element, and more preferably less than 0.1 mmH2O per 10 mm length hollow tubular segment or hollow tubular element.

[0028] Therefore, the flow channel should not contain any components that would obstruct the longitudinal airflow. Preferably, the flow channel is substantially empty.

[0029] In this specification, “hollow tubular segment” or “hollow tubular element” may also be referred to as “hollow tube” or “hollow tube segment.”

[0030] In some embodiments, the aerosol-generating article may have a ventilation zone located along the downstream section. More specifically, the aerosol-generating article may have a ventilation zone located along a hollow tubular element. In this way, a fluid communication is established between the flow path defined inside by the hollow tubular element and the external environment.

[0031] The aerosol generating article further comprises an upstream section located upstream of the rod of the aerosol generating substrate. The upstream section may comprise one or more upstream elements. In some embodiments, the upstream section may comprise an upstream element located immediately upstream of the aerosol generating element.

[0032] As briefly explained above, the aerosol generating article according to the present invention comprises an element that includes an aerosol generating substrate.

[0033] In some embodiments, the aerosol generating element may be provided in the form of a rod comprising an aerosol generating substrate. For example, the aerosol generating element may comprise a rod of an aerosol generating substrate surrounded by a wrapper.

[0034] The element comprising the aerosol generating substrate may have a length of at least about 5 millimeters. Preferably, the element comprising the aerosol generating substrate has a length of at least about 7 millimeters. More preferably, the element comprising the aerosol generating substrate has a length of at least about 10 millimeters. In a particularly preferred embodiment, the element comprising the aerosol generating substrate has a length of at least about 12 millimeters.

[0035] The element comprising the aerosol generating substrate can have a maximum length of approximately 80 millimeters. Preferably, the element comprising the aerosol generating substrate has a length of approximately 65 millimeters or less. More preferably, the element comprising the aerosol generating substrate has a length of approximately 60 millimeters or less. Even more preferably, the element comprising the aerosol generating substrate has a length of approximately 55 millimeters or less.

[0036] In a particularly preferred embodiment, the element comprising the aerosol generating substrate has a length of about 50 mm or less, more preferably about 35 mm or less, and even more preferably about 25 mm or less. In a particularly preferred embodiment, the element comprising the aerosol generating substrate has a length of about 20 mm or less, or about 15 mm or less.

[0037] In some embodiments, the element comprising the aerosol generating substrate has a length of about 5 mm to about 60 mm, preferably about 6 mm to about 60 mm, more preferably about 7 mm to about 60 mm, even more preferably about 10 mm to about 60 mm, and most preferably about 12 mm to about 60 mm. In another embodiment, the element comprising the aerosol generating substrate has a length of about 5 mm to about 55 mm, preferably about 6 mm to about 55 mm, more preferably about 7 mm to about 55 mm, even more preferably about 10 mm to about 55 mm, and most preferably about 12 mm to about 55 mm. In yet another embodiment, the element comprising the aerosol generating substrate has a length of about 5 mm to about 50 mm, preferably about 6 mm to about 50 mm, more preferably about 7 mm to about 50 mm, even more preferably about 10 mm to about 50 mm, and most preferably about 12 mm to about 50 mm.

[0038] In some particularly preferred embodiments, the element comprising the aerosol generating substrate has a length of about 5 mm to about 30 mm, preferably about 6 mm to about 30 mm, more preferably about 7 mm to about 30 mm, and even more preferably about 10 mm to about 30 mm. In another particularly preferred embodiment, the element comprising the aerosol generating substrate has a length of about 5 mm to about 20 mm, preferably about 6 mm to about 20 mm, more preferably about 7 mm to about 20 mm, and even more preferably about 10 mm to about 20 mm. In yet another particularly preferred embodiment, the element comprising the aerosol generating substrate has a length of about 5 mm to about 15 mm, preferably about 7 mm to about 20 mm, more preferably about 9 mm to about 16 mm, and even more preferably about 10 mm to about 15 mm.

[0039] The rod-shaped element equipped with the aerosol generating substrate preferably has an outer diameter that is approximately equal to the outer diameter of the aerosol generating article.

[0040] The element comprising the aerosol generating substrate preferably has an outer diameter of at least about 5 mm. More preferably, the element comprising the aerosol generating substrate has an outer diameter of at least about 6 mm. Even more preferably, the element comprising the aerosol generating substrate has an outer diameter of at least about 7 mm.

[0041] The element containing the aerosol generating substrate preferably has an outer diameter of about 12 mm or less. More preferably, the element containing the aerosol generating substrate has an outer diameter of about 10 mm or less. Even more preferably, the element containing the aerosol generating substrate has an outer diameter of about 8 mm or less.

[0042] Generally, it has been observed that the smaller the diameter of a rod-shaped element containing an aerosol-generating substrate, the lower the temperature required to raise the core temperature of the aerosol-generating element, allowing a sufficient amount of vaporized species to be released from the aerosol-generating substrate and form the desired amount of aerosol. At the same time, although we do not wish to be bound by any theory, it is understood that the smaller the diameter of a rod-shaped element containing an aerosol-generating substrate, the faster the heat supplied to the aerosol-generating article can penetrate into the total volume of the aerosol-forming substrate. Nevertheless, if the diameter of the rod-shaped element containing the aerosol-generating substrate is too small, the amount of available aerosol-forming substrate decreases, resulting in an unfavorable ratio of the volume of the aerosol-generating substrate to the surface.

[0043] The diameters of rod-shaped elements comprising aerosol-generating substrates within the range described herein are particularly advantageous in terms of the balance between energy consumption and aerosol delivery. This advantage is particularly evident when an aerosol-generating article comprising a rod with an aerosol-generating substrate having the diameter described herein is used in combination with an external heater positioned around the outer surface of the aerosol-generating article. Under such operating conditions, it has been observed that less thermal energy is required to achieve sufficiently high temperatures in the core of the rod comprising the aerosol-generating substrate, and generally in the core of the article. This allows the desired target temperature in the core of the aerosol-generating substrate to be achieved, when operating at lower temperatures, within a preferably shortened time frame and with lower energy consumption.

[0044] In some embodiments, the element comprising the aerosol generating substrate has an outer diameter of about 5 mm to about 12 mm, preferably about 6 mm to about 12 mm, and more preferably about 7 mm to about 12 mm. In another embodiment, the element comprising the aerosol generating substrate has an outer diameter of about 5 mm to about 12 mm, preferably about 6 mm to about 10 mm, and more preferably about 7 mm to about 10 mm. In yet another embodiment, the element comprising the aerosol generating substrate has an outer diameter of about 5 mm to about 8 mm, preferably about 6 mm to about 8 mm, and more preferably about 7 mm to about 8 mm.

[0045] In a particularly preferred embodiment, the element comprising the aerosol generating substrate has an outer diameter of less than approximately 7.5 millimeters. As an example, the element comprising the aerosol generating substrate may have an outer diameter of approximately 7.2 millimeters.

[0046] As briefly explained above, the ratio of the length of the aerosol generating element to its diameter is at least about 0.5. Preferably, the ratio is at least about 0.75. More preferably, the ratio is at least about 1.0. Even more preferably, the ratio is at least about 1.25.

[0047] Furthermore, the ratio of the length of the aerosol generating element to its diameter is approximately 3.0 or less. Preferably, the ratio of the length of the aerosol generating element to its diameter is approximately 2.75 or less. More preferably, the ratio of the length of the aerosol generating element to its diameter is approximately 2.5 or less. Even more preferably, the ratio of the length of the aerosol generating element to its diameter is approximately 2.25 or less.

[0048] More specifically, in the aerosol generating article according to the present invention, the ratio of the length to the diameter of the aerosol generating element is approximately 0.5 to approximately 3.0.

[0049] The ratio of the length to the diameter of the aerosol generating element is preferably about 0.75 to about 3.0. The ratio of the length to the diameter of the aerosol generating element is more preferably about 1.0 to about 3.0. The ratio of the length to the diameter of the aerosol generating element is even more preferably about 1.25 to about 3.0.

[0050] In another embodiment, the ratio of the length to the diameter of the aerosol generating element may be about 0.5 to about 2.75. A ratio of about 0.75 to about 2.75 is preferred for the aerosol generating element. A ratio of about 1.0 to about 2.75 is more preferred for the aerosol generating element. A ratio of about 1.25 to about 2.75 is even more preferred for the aerosol generating element.

[0051] In another embodiment, the ratio of the length to the diameter of the aerosol generating element can be about 0.5 to about 2.5. Preferably, the ratio of the length to the diameter of the aerosol generating element is about 0.75 to about 2.5. More preferably, the ratio of the length to the diameter of the aerosol generating element is about 1.0 to about 2.5. Even more preferably, the ratio of the length to the diameter of the aerosol generating element is about 1.25 to about 2.5.

[0052] In yet another embodiment, the ratio of the length to the diameter of the aerosol generating element can be about 0.5 to about 2.25. Preferably, the ratio of the length to the diameter of the aerosol generating element is about 0.75 to about 2.25. More preferably, the ratio of the length to the diameter of the aerosol generating element is about 1.0 to about 2.25. Even more preferably, the ratio of the length to the diameter of the aerosol generating element is about 1.25 to about 2.25.

[0053] In a particularly preferred embodiment, the ratio of the length to the diameter of the aerosol generating element can be at least about 1.3, more preferably about 1.4, and even more preferably about 1.5.

[0054] In a particularly preferred embodiment, the ratio of the length to the diameter of the aerosol generating element can be about 2.0 or less, more preferably about 1.9 or less, and even more preferably about 1.8 or less.

[0055] In some embodiments, the ratio of the length to the diameter of the aerosol generating element is preferably about 1.3 to about 2.0, more preferably about 1.4 to about 2.0, and even more preferably about 1.5 to about 2.0. In another embodiment, the ratio of the length to the diameter of the aerosol generating element is preferably about 1.3 to about 1.9, more preferably about 1.4 to about 1.9, and even more preferably about 1.5 to about 1.9. In yet another embodiment, the ratio of the length to the diameter of the aerosol generating element is preferably about 1.3 to about 1.8, more preferably about 1.4 to about 1.8, and even more preferably about 1.5 to about 1.8.

[0056] The ratio of the length of the aerosol generating element to the total length of the aerosol generating article can be at least about 0.10. Preferably, the ratio is at least about 0.15. More preferably, the ratio is at least about 0.20. Even more preferably, the ratio is at least about 0.25.

[0057] Typically, the ratio of the length of the aerosol generating element to the total length of the aerosol generating article can be about 0.60 or less. Preferably, the ratio is about 0.50 or less. More preferably, the ratio is about 0.45 or less. Even more preferably, the ratio is about 0.40 or less. In a particularly preferred embodiment, the ratio is about 0.35 or less, and most preferably about 0.30 or less.

[0058] In some embodiments, the ratio of the length of the aerosol generating element to the total length of the aerosol generating article is about 0.10 to about 0.45, preferably about 0.15 to about 0.45, more preferably about 0.20 to about 0.45, and even more preferably about 0.25 to about 0.45. In another embodiment, the ratio of the length of the aerosol generating element to the total length of the aerosol generating article is 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. In yet another embodiment, the ratio of the length of the aerosol generating element to the total length of the aerosol generating article is about 0.10 to about 0.35, preferably about 0.15 to about 0.35, more preferably about 0.20 to about 0.35, and even more preferably about 0.25 to about 0.35. In yet another embodiment, the ratio of the length of the aerosol generating element to the total length of the aerosol generating article is about 0.10 to about 0.30, preferably about 0.15 to about 0.30, more preferably about 0.20 to about 0.30, and even more preferably about 0.25 to about 0.30.

[0059] The aerosol generating element preferably comprises a rod-shaped element of an aerosol generating substrate having a substantially uniform cross-section along the length of the element. The rod-shaped element comprising the aerosol generating substrate is particularly preferably substantially circular in cross-section.

[0060] As will be described in more detail below, the aerosol generating article according to the present invention comprises a downstream section having a hollow tubular element. In the aerosol generating article according to the present invention, the ratio of the length of the aerosol generating element to the length of the hollow tubular element can be about 0.66 or less. Preferably, the ratio of the length of the aerosol generating element to the length of the hollow tubular element may be about 0.60 or less. More preferably, the ratio of the length of the aerosol generating element to the length of the hollow tubular element may be about 0.50 or less. Even more preferably, the ratio of the length of the aerosol generating element to the length of the hollow tubular element may be about 0.40 or less.

[0061] In the aerosol generating article according to the present invention, the ratio of the length of the aerosol generating element to the length of the hollow tubular element can be at least about 0.10. Preferably, the ratio of the length of the aerosol generating element to the length of the hollow tubular element may be at least about 0.15. More preferably, the ratio of the length of the aerosol generating element to the length of the hollow tubular element may be at least about 0.20. Even more preferably, the ratio of the length of the aerosol generating element to the length of the hollow tubular element may be at least about 0.25. In a particularly preferred embodiment, the ratio of the length of the aerosol generating element to the length of the hollow tubular element may be at least about 0.30.

[0062] In some embodiments, the ratio of the length of the aerosol generating element to the length of the hollow tubular element is about 0.15 to about 0.60, preferably about 0.20 to about 0.60, more preferably about 0.25 to about 0.60, and even more preferably about 0.30 to about 0.60. In another embodiment, the ratio of the length of the aerosol generating element to the length of the hollow tubular element is about 0.15 to about 0.50, preferably about 0.20 to about 0.50, more preferably about 0.25 to about 0.50, and even more preferably about 0.30 to about 0.50. In yet another embodiment, the ratio of the length of the aerosol generating element to the length of the hollow tubular element is about 0.15 to about 0.40, preferably about 0.20 to about 0.40, more preferably about 0.25 to about 0.40, and even more preferably about 0.30 to about 0.40. For example, the ratio of the length of the aerosol-generating element to the length of the hollow tubular element can be approximately 0.35.

[0063] The density of the aerosol generating substrate can be at least about 100 micrograms / cubic centimeter. Preferably, the density of the aerosol generating substrate is at least about 115 micrograms / cubic centimeter. More preferably, the density of the aerosol generating substrate is at least about 130 micrograms / cubic centimeter. Even more preferably, the density of the aerosol generating substrate is at least about 140 micrograms / cubic centimeter.

[0064] The density of the aerosol generating substrate can be about 200 micrograms / cubic centimeter or less. Preferably, the density of the aerosol generating substrate is about 185 micrograms / cubic centimeter or less. More preferably, the density of the aerosol generating substrate is about 170 micrograms / cubic centimeter or less. Even more preferably, the density of the aerosol generating substrate is about 160 micrograms / cubic centimeter or less.

[0065] In some embodiments, the density of the aerosol-generating substrate is 100 micrograms / cubic centimeter to 200 micrograms / cubic centimeter, preferably 100 micrograms / cubic centimeter to 185 micrograms / cubic centimeter, more preferably 100 micrograms / cubic centimeter to 170 micrograms / cubic centimeter, and even more preferably 100 micrograms / cubic centimeter to 160 micrograms / cubic centimeter. In another embodiment, the density of the aerosol-generating substrate is 115 micrograms / cubic centimeter to 200 micrograms / cubic centimeter, preferably 115 micrograms / cubic centimeter to 185 micrograms / cubic centimeter, more preferably 115 micrograms / cubic centimeter to 170 micrograms / cubic centimeter, and even more preferably 115 micrograms / cubic centimeter to 160 micrograms / cubic centimeter. In another embodiment, the density of the aerosol-generating substrate is 130 micrograms / cubic centimeter to 200 micrograms / cubic centimeter, preferably 130 micrograms / cubic centimeter to 185 micrograms / cubic centimeter, more preferably 130 micrograms / cubic centimeter to 170 micrograms / cubic centimeter, and even more preferably 130 micrograms / cubic centimeter to 160 micrograms / cubic centimeter. In yet another embodiment, the density of the aerosol-generating substrate is 140 micrograms / cubic centimeter to 200 micrograms / cubic centimeter, preferably 140 micrograms / cubic centimeter to 185 micrograms / cubic centimeter, more preferably 140 micrograms / cubic centimeter to 170 micrograms / cubic centimeter, and even more preferably 140 micrograms / cubic centimeter to 160 micrograms / cubic centimeter. In some particularly preferred embodiments, the density of the aerosol-generating substrate is about 150 micrograms / cubic centimeter.

[0066] The density of the aerosol generating substrate can be at least about 100 milligrams / cubic centimeter. Preferably, the density of the aerosol generating substrate is at least about 115 milligrams / cubic centimeter. More preferably, the density of the aerosol generating substrate is at least about 130 milligrams / cubic centimeter. Even more preferably, the density of the aerosol generating substrate is at least about 140 milligrams / cubic centimeter.

[0067] The density of the aerosol generating substrate can be about 200 milligrams / cubic centimeter or less. Preferably, the density of the aerosol generating substrate is about 185 milligrams / cubic centimeter or less. More preferably, the density of the aerosol generating substrate is about 170 milligrams / cubic centimeter or less. Even more preferably, the density of the aerosol generating substrate is about 160 milligrams / cubic centimeter or less.

[0068] In some embodiments, the density of the aerosol-generating substrate is 100 milligrams / cubic centimeter to 200 milligrams / cubic centimeter, preferably 100 milligrams / cubic centimeter to 185 milligrams / cubic centimeter, more preferably 100 milligrams / cubic centimeter to 170 milligrams / cubic centimeter, and even more preferably 100 milligrams / cubic centimeter to 160 milligrams / cubic centimeter. In another embodiment, the density of the aerosol-generating substrate is 115 milligrams / cubic centimeter to 200 milligrams / cubic centimeter, preferably 115 milligrams / cubic centimeter to 185 milligrams / cubic centimeter, more preferably 115 milligrams / cubic centimeter to 170 milligrams / cubic centimeter, and even more preferably 115 milligrams / cubic centimeter to 160 milligrams / cubic centimeter. In another embodiment, the density of the aerosol-generating substrate is 130 milligrams / cubic centimeter to 200 milligrams / cubic centimeter, preferably 130 milligrams / cubic centimeter to 185 milligrams / cubic centimeter, more preferably 130 milligrams / cubic centimeter to 170 milligrams / cubic centimeter, and even more preferably 130 milligrams / cubic centimeter to 160 milligrams / cubic centimeter. In yet another embodiment, the density of the aerosol-generating substrate is 140 milligrams / cubic centimeter to 200 milligrams / cubic centimeter, preferably 140 milligrams / cubic centimeter to 185 milligrams / cubic centimeter, more preferably 140 milligrams / cubic centimeter to 170 milligrams / cubic centimeter, and even more preferably 140 milligrams / cubic centimeter to 160 milligrams / cubic centimeter. In some particularly preferred embodiments, the density of the aerosol-generating substrate is 150 milligrams / cubic centimeter.

[0069] As an example, the aerosol generating element may comprise about 100 milligrams to about 250 milligrams of aerosol generating substrate. In some embodiments, the aerosol generating element comprises about 210 milligrams to about 230 milligrams of aerosol generating substrate, with 215 milligrams to about 220 milligrams being preferred. In another embodiment, the aerosol generating element comprises about 150 milligrams to about 180 milligrams of aerosol generating substrate, with 160 milligrams to about 165 milligrams being preferred.

[0070] The aerosol generating article according to the present invention is an aerosol generating substrate in which the aerosol generating substrate is solid. More specifically, as briefly described above, the aerosol generating substrate includes a cut filler.

[0071] In the context of this specification, the term “cut filler” is used to describe a blend of shredded plant material, such as tobacco plant material, which in particular includes one or more of leaf flakes, processed stems and veins, and homogenized plant material.

[0072] As used herein, the term “homogenized plant material” encompasses any plant material formed by the aggregation of plant particles. For example, a sheet or web of homogenized tobacco material for the aerosol-generating substrate of the present invention may be formed by aggregating plant material and, optionally, one or more tobacco leaf laminas and tobacco leaf stems, which are obtained by grinding, crushing, or pulverizing tobacco material particles. The homogenized plant material may be produced by casting, extrusion, papermaking processes, or any other suitable process known in the art.

[0073] Cut fillers may also include other cut pieces, filler tobacco, or casing.

[0074] Preferably, the cut filler contains at least 25 percent plant leaf lamina, more preferably at least 50 percent plant leaf lamina, even more preferably at least 75 percent plant leaf lamina, and most preferably at least 90 percent plant leaf lamina. Preferably, the plant material is one of tobacco, mint, tea, and clove. However, the present invention is equally applicable to other plant materials that, when heated, have the ability to release a substance which can then form an aerosol, as will be described in more detail below.

[0075] The cut filler preferably comprises tobacco plant material including one or more laminas from bright tobacco, dark tobacco, aromatic tobacco, and filler tobacco. In relation to the present invention, the term "tobacco" refers to any plant member of the genus Nicotiana.

[0076] Bright tobacco is tobacco that generally has large, light-colored leaves. Throughout this specification, the term “bright tobacco” is used for fully cured tobacco. Examples of bright tobacco include fully cured tobacco from China, fully cured tobacco from Brazil, fully cured tobacco from the United States (such as Virginia tobacco), fully cured tobacco from India, fully cured tobacco from Tanzania, or fully cured tobacco from other African countries. Bright tobacco is characterized by a high sugar-to-nitrogen ratio. From a sensory perspective, bright tobacco is a type of tobacco that, after curing, has a spicy and lively character. In the context of this invention, bright tobacco is tobacco in which the reducing sugar content is about 2.5 percent to about 20 percent on a dry weight basis of the leaves, and the total ammonia content is less than about 0.12 percent on a dry weight basis of the leaves. Reducing sugars include, for example, glucose or fructose. Total ammonia includes, for example, ammonia and ammonium salts.

[0077] Dark tobacco is tobacco that generally has large, dark-colored leaves. Throughout this specification, the term “dark tobacco” is used for air-cured tobacco. Additionally, dark tobacco may be fermented. Tobacco used primarily for chewing tobacco, snuff, cigar tobacco, and pipe blends also falls into this category. Typically, these dark tobaccos may be air-dried and fermented. From a sensory perspective, dark tobacco is a type of tobacco that, after drying, has a smoky, dark cigar-like feel. Dark tobacco is characterized by a low sugar-to-nitrogen ratio. Examples of dark tobacco include Burley Malawi or other African Burley, dark-cured Brazil Galpao, Sun Cure, or air-cured Indonesian Kasturi. According to the present invention, dark tobacco is tobacco in which the reducing sugar content is less than about 5 percent on a dry weight basis of the leaves, and the total ammonia content is less than or equal to about 0.5 percent on a dry weight basis of the leaves.

[0078] Aromatic tobacco is tobacco that often has small, light-colored leaves. Throughout this specification, the term “aromatic tobacco” is used for other tobaccos that have a high content of aromatic compounds, such as essential oils. From a sensory perspective, aromatic tobacco is a type of tobacco that, after drying, has a spicy and aromatic scent. Examples of aromatic tobacco include Greek Orient, Orient Turkey, semi-orient leaf tobaccos that have been heat-dried, US Burley such as Perique, Rustica, US Burley, or Maryland. Filler tobacco is not a specific tobacco type but includes tobacco types that are used in blends and are primarily used to complement other tobacco types that do not give the final product a specific characteristic aromatic direction. Examples of filler tobacco are the stems, midribs, or petioles of other tobacco types. A specific example may be the heat-dried stems of the lower petioles of Brazilian hot-air-dried petioles.

[0079] The cut filler suitable for use in the present invention may generally be similar to the cut fillers used in conventional smoking articles. The cut width of the cut filler is preferably 0.3 mm to 2.0 mm, more preferably 0.5 mm to 1.2 mm, and most preferably 0.6 mm to 0.9 mm. The cut width may affect the heat distribution within the aerosol generating element. The cut width may also play a role in the pull-out resistance of the article. Furthermore, the cut width as a whole may affect the overall density of the aerosol generating substrate.

[0080] Since the strand length depends on the overall size of the object from which the strand is cut, the strand length of cut filler is somewhat random. Nevertheless, longer strands can be cut by conditioning the material before cutting, for example, by controlling the moisture content and overall delicacy of the material. Preferably, the strands have a length of about 10 mm to about 40 mm, and then the strands are bundled together to form an aerosol generating element. Obviously, if the strands are positioned longitudinally in an aerosol generating element where the longitudinally extending portion of the section is less than 40 mm, the final aerosol generating element may have strands that are shorter on average than the initial strand length. Preferably, the strand length of the cut filler is such that about 20 percent to 60 percent of the strands extend along the entire length of the aerosol generating element. This prevents the strands from easily falling out of the aerosol generating element.

[0081] In a preferred embodiment, the weight of the cut filler is 80 to 400 milligrams, preferably 150 to 250 milligrams, and more preferably 170 to 220 milligrams. This amount of cut filler usually allows for sufficient material for aerosol formation. Furthermore, in terms of the aforementioned constraints on diameter and size, this allows for a balanced density of the aerosol-generating element between energy absorption, resistance to pull-in, and fluid passages within the aerosol-generating element containing the plant material.

[0082] Preferably, the cut filler is immersed in an aerosol-forming material. Immersion of the cut filler can be carried out by spraying or other suitable application methods. The aerosol-forming material can be added to the blend during the preparation of the cut filler. For example, the aerosol-forming material may be applied directly to the blend in the conditioning casing cylinder (DCCC). Conventional machinery can be used to add the aerosol-forming material to the cut filler. The aerosol-forming material can be any suitable known compound or mixture of compounds that promotes the formation of a dense and stable aerosol when used. The aerosol-forming material can promote the aerosol's substantial resistance to thermal decomposition at the temperatures typically applied during use of the aerosol-generating article. Suitable aerosol-forming agents include, for example, polyhydric alcohols (e.g., triethylene glycol, 1,3-butanediol, propylene glycol, and glycerin), esters of polyhydric alcohols (e.g., glycerol monoacetate, diacetate, or triacetate), aliphatic esters of monocarboxylic acids, dicarboxylic acids, or polycarboxylic acids (e.g., dimethyl dodecanediate and dimethyl tetradecanediate), and combinations thereof.

[0083] The aerosol-forming body preferably contains one or more of glycerin and propylene glycol. The aerosol-forming body may consist of glycerin or propylene glycol, or a combination of glycerin and propylene glycol.

[0084] As briefly explained above, in the aerosol generating article according to the present invention, the aerosol-forming material content in the aerosol generating substrate is at least about 8% by weight on a dry weight basis of the cut filler. Preferably, the aerosol-forming material content in the aerosol generating substrate is about 20% by weight or less on a dry weight basis of the cut filler.

[0085] Preferably, the amount of aerosol former is 8% to 18% by weight based on the dry weight of the cut filler, and most preferably, the amount of aerosol former is 10% to 15% by weight based on the dry weight of the cut filler. In some embodiments, the amount of aerosol former has a target value of about 13% by weight 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 laminas or homogenized plant material. For example, among the factors, the type of cut filler will determine to what extent the aerosol former can promote the release of material from the cut filler.

[0086] For these reasons, aerosol generating elements containing the above-mentioned cut fillers can efficiently generate a sufficient amount of aerosol at relatively low temperatures. While temperatures of 150°C to 200°C in the heating chamber are sufficient for such cut fillers to generate a sufficient amount of aerosol, aerosol generators using tobacco cast leaf sheets typically use temperatures of around 250°C.

[0087] A further advantage associated with operation at lower temperatures is the reduced need to cool the aerosol. Since generally lower temperatures are used, simpler cooling mechanisms may suffice. This, in turn, allows for the use of simpler and less complex structures for aerosol-generating articles.

[0088] Preferably, if the aerosol-generating substrate includes a cut filler obtained from homogenized plant material by methods such as cutting or shredding, the homogenized plant material is provided in the form of a sheet. As an example, a sheet of homogenized plant material may be manufactured by a casting process or a papermaking process.

[0089] Each sheet described herein may individually have a thickness of 100 to 600 micrometers, preferably 150 to 300 micrometers, and most preferably 200 to 250 micrometers.

[0090] Each sheet described herein may individually have a basis weight of approximately 100 grams per square meter to approximately 300 grams per square meter.

[0091] Each sheet described herein may individually have a density of about 0.3 grams / cubic centimeter to about 1.3 grams / cubic centimeter, preferably about 0.7 grams / cubic centimeter to about 1.0 gram / cubic centimeter.

[0092] The homogenized plant material may contain up to about 95 weight percent of plant particles on a dry weight basis. Preferably, the homogenized plant material contains up to about 90 weight percent of plant particles on a dry weight basis, more preferably about 80 weight percent of plant particles, more preferably about 70 weight percent of plant particles, more preferably about 60 weight percent of plant particles, and more preferably about 50 weight percent of plant particles.

[0093] For example, the homogenized plant material may contain, on a dry weight basis, approximately 2.5 to 95 percent by weight of plant particles, or approximately 5 to 90 percent by weight of plant particles, or approximately 10 to 80 percent by weight of plant particles, or approximately 15 to 70 percent by weight of plant particles, or approximately 20 to 60 percent by weight of plant particles, or approximately 30 to 50 percent by weight of plant particles.

[0094] In certain embodiments of the present invention, the homogenized plant material is a homogenized tobacco material containing tobacco particles. A sheet of the homogenized tobacco material used in such embodiments of the present invention may have a tobacco content of at least about 40 weight percent on a dry weight basis, more preferably at at least about 50 weight percent on a dry weight basis, more preferably at at least about 70 weight percent on a dry weight basis, and most preferably at at least about 90 weight percent on a dry weight basis.

[0095] 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 crushed or powdered tobacco leaf lamina, crushed or powdered tobacco leaf stems, tobacco dust, tobacco fine powder, and other particulate tobacco by-products formed during the processing, handling, and shipping of tobacco. In preferred embodiments, tobacco particles are substantially all derived from tobacco leaf lamina. In contrast, separated 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 proportion of particulate plant material.

[0096] Tobacco particles may be prepared from one or more varieties of tobacco plants. Any type of tobacco may be used in the blend. Examples of types of tobacco materials that may be used include, but are not limited to, sun-dried tobacco, fire-dried tobacco, Burley tobacco, Maryland tobacco, Oriental tobacco, Virginia tobacco, and other specialty tobaccos.

[0097] Heat drying is a tobacco drying method particularly used for Virginia tobacco. During the heat drying process, heated air circulates through the densely packed tobacco. In the first stage, the tobacco leaves turn yellow and wither. In the second stage, the leaf laminas dry completely. In the third stage, the leaf stems dry completely.

[0098] Burley tobacco plays an important role in many tobacco blends. It possesses a distinctive flavor and aroma, and has the ability to absorb a large amount of casing.

[0099] Oriental tobacco is a type of tobacco with small leaves and high aromatic quality. However, Oriental tobacco has a milder flavor than, for example, Burley tobacco. Therefore, Oriental tobacco is generally used in relatively small proportions in tobacco blends.

[0100] Kasturi, Madura, and Jatim are usable subtypes of sun-dried tobacco. It is preferable to use Kasturi tobacco and heat-dried tobacco in the blend to produce tobacco particles. Therefore, tobacco particles in particulate plant material may include a blend of Kasturi tobacco and heat-dried tobacco.

[0101] Tobacco particles may have a nicotine content of at least about 2.5 weight percent based on dry weight. More preferably, tobacco particles may have a nicotine content of at least about 3 weight percent based on dry weight, even more preferably at least about 3.2 weight percent, even more preferably at least about 3.5 weight percent, and most preferably at least about 4 weight percent.

[0102] In certain other embodiments of the present invention, the homogenized plant material includes tobacco particles in combination with non-tobacco plant-flavored particles. Preferably, the non-tobacco plant-flavored particles are selected from one or more of ginger particles, eucalyptus particles, clove particles, and star anise particles. Preferably, in such embodiments, the homogenized plant material contains at least about 2.5 weight percent of non-tobacco plant-flavored particles on a dry weight basis, with the remaining plant particles being tobacco particles. Preferably, the homogenized plant material contains at least about 4 weight percent of non-tobacco plant-flavored particles on a dry weight basis, more preferably at least about 6 weight percent of non-tobacco plant-flavored particles, more preferably at least about 8 weight percent of non-tobacco plant-flavored particles, and more preferably at least about 10 weight percent of non-tobacco plant-flavored particles. Preferably, the homogenized plant material contains up to about 20 weight percent of non-tobacco plant-flavored particles, more preferably up to about 18 weight percent of non-tobacco plant-flavored particles, and more preferably up to about 16 weight percent of non-tobacco plant-flavored particles.

[0103] The weight ratio of non-tobacco plant-flavored particles to tobacco particles in the particulate plant material forming the homogenized plant material may vary depending on the desired flavor characteristics and composition of the aerosol generated from the aerosol-generating substrate during use. Preferably, the homogenized plant material contains, on a dry weight basis, at least 1:30 weight ratio of non-tobacco plant-flavored particles to tobacco particles, more preferably at least 1:20 weight ratio of non-tobacco plant-flavored particles to tobacco particles, more preferably at least 1:10 weight ratio of non-tobacco plant-flavored particles to tobacco particles, and most preferably at least 1:5 weight ratio of non-tobacco plant-flavored particles to tobacco particles.

[0104] As an alternative to, or in addition to, the homogenized plant material of the aerosol-generating substrate according to the present invention, the homogenized plant material may also contain cannabis particles. The term "cannabis particles" refers to particles of cannabis plants such as Cannabis sativa, Cannabis indica, and Cannabis ruderalis.

[0105] The homogenized plant material preferably contains 95% by weight or less of particulate plant material on a dry weight basis. Thus, the particulate plant material is typically combined with one or more other components to form the homogenized plant material.

[0106] The homogenized plant material may further contain a binder for altering the mechanical properties of the particulate plant material, where the binder is included in the homogenized plant material during production as described herein. Suitable exogenous binders known to those skilled in the art include, but are not limited to, gums such as guar gum, xanthan gum, gum arabic, and locust bean gum; cellulose binders such as hydroxypropyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, methyl cellulose, and ethyl cellulose; polysaccharides such as starch, organic acids such as alginic acid, conjugated base salts of organic acids such as sodium alginate, agar, and pectin, and combinations thereof. The binder preferably contains guar gum.

[0107] The binder may be present in an amount of about 1% to about 10% by weight, preferably about 2% to about 5% by weight, based on the dry weight of the homogenized plant material.

[0108] Alternatively, or additionally, the homogenized plant material may further contain one or more lipids to facilitate the diffusion of volatile components (e.g., aerosol-forming agents, gingerol, and nicotine), wherein the lipids are included in the homogenized plant material during the manufacturing process described herein. Suitable lipids for inclusion in the homogenized plant material include, but are not limited to, medium-chain triglycerides, cocoa butter, palm oil, palm kernel oil, mango oil, shea butter, soybean oil, cottonseed oil, coconut oil, hydrogenated coconut oil, candelilla wax, carnauba wax, shellac, sunflower wax, sunflower oil, rice bran, and Revel A, as well as combinations thereof.

[0109] Alternatively, or additionally, the homogenized plant material may further contain a pH adjuster.

[0110] Alternatively, or additionally, the homogenized plant material may further contain fibers to alter the mechanical properties of the homogenized plant material, wherein the fibers are included in the homogenized plant material during the manufacturing process described herein. Suitable exogenous fibers for inclusion in the homogenized plant material are known in the art and include, but are not limited to, cellulose fibers, soft wood fibers, hard wood fibers, jute fibers, and combinations thereof, as well as fibers formed from non-tobacco and non-ginger materials. Exogenous fibers derived from tobacco and / or ginger may also be added. Any fibers added to the homogenized plant material are not considered to form part of the “particulate plant material” as defined above. Before inclusion in the homogenized plant material, the fibers may be treated by suitable processes known in the art, including, but not limited to, mechanical pulping, purification, chemical pulping, bleaching, sulfate pulping, and combinations thereof. Typically, the fibers have a length greater than their width.

[0111] Preferred fibers are typically greater than 400 micrometers and have a length of 4 millimeters or less, preferably in the range of 0.7 millimeters to 4 millimeters. The fibers are preferably present in an amount of about 2% to about 15% by weight, most preferably about 4% by weight, based on the dry weight of the substrate.

[0112] Alternatively, or additionally, the homogenized plant material may further contain one or more aerosol-forming bodies. As they volatilize, the aerosol-forming bodies can carry other vaporized compounds released from the aerosol-generating substrate upon heating, such as nicotine and flavorings in the aerosol. Suitable aerosol-forming bodies 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 (glycerol mono-, di-, or triacetate), and aliphatic esters of mono-, di-, or polycarboxylic acids (such as dodecanedioic acid and dimethyl tetradecanedioic acid).

[0113] Homogenized plant material may have an aerosol-forming content of approximately 5% to 30% by dry weight, such as approximately 10% to 25% by dry weight, or approximately 15% to 20% by dry weight.

[0114] For example, when intended for use in an aerosol generating article for an electrically operated aerosol generating system having a substrate that has a heating element, it is preferable that the aerosol-forming material content be about 5% to about 30% by weight on a dry weight basis. When intended for use in an aerosol generating article for an electrically operated aerosol generating system having a substrate that has a heating element, the aerosol-forming material is preferably glycerol.

[0115] In other embodiments, the homogenized plant material may have an aerosol-forming content of about 1% to about 5% by weight on a dry weight basis. For example, if the substrate is intended for use in an aerosol-generating article in which the aerosol-forming material is kept in a storage compartment separated from the substrate, the substrate may have an aerosol-forming content greater than 1% and less than about 5%. In such embodiments, the aerosol-forming material volatilizes upon heating, and the flow of the aerosol-forming material comes into contact with the aerosol-generating substrate to infuse flavor from the aerosol-generating substrate into the aerosol.

[0116] In other embodiments, the homogenized plant material may have an aerosol-forming content of about 30 to about 45 weight percent. This relatively high level of aerosol-forming is particularly suitable for aerosol-generating substrates intended to be heated at temperatures below 275 degrees Celsius. In such embodiments, the homogenized plant material preferably further comprises about 2 to about 10 weight percent of cellulose ether and about 5 to about 50 weight percent of additional cellulose on a dry weight basis. The use of a combination of cellulose ether and additional cellulose has been found to result in particularly effective aerosol delivery when used in aerosol-generating substrates having an aerosol-forming content of 30 to 45 weight percent.

[0117] Suitable cellulose ethers include, but are not limited to, methylcellulose, hydroxypropylmethylcellulose, ethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, ethylhydroxyethylcellulose, and carboxymethylcellulose (CMC). In a particularly preferred embodiment, the cellulose ether is carboxymethylcellulose.

[0118] As used herein, the term “additional cellulose” encompasses any cellulose material incorporated into the homogenized plant material, which is not derived from the non-tobacco plant particles or tobacco particles provided to the homogenized plant material. Thus, additional cellulose is incorporated into the homogenized plant material as an individual and distinct source of cellulose to any cellulose essentially provided within the non-tobacco plant particles or tobacco particles, in addition to the non-tobacco plant material or tobacco material. The additional cellulose is typically derived from a plant different from the non-tobacco plant particles or tobacco particles. Preferably, the additional cellulose is in the form of an inert cellulose material, which is sensorily inert and therefore does not substantially affect the functional properties of the aerosol generated from the aerosol-generating substrate. For example, the additional cellulose is preferably a tasteless and odorless material.

[0119] The additional cellulose may include cellulose powder, cellulose fibers, or a combination thereof.

[0120] The aerosol-forming material can act as a wetting agent in the aerosol-generating substrate.

[0121] The wrapper surrounding the rod of homogenized plant material may be a paper wrapper or a non-paper wrapper. Suitable paper wrappers for use in specific embodiments of the present invention are known in the art and include, but are not limited to, cigarette papers and filter plug wrappers. Suitable non-paper wrappers for use in specific embodiments of the present invention are known in the art and include, but are not limited to, sheets of homogenized tobacco material. In certain preferred embodiments, the wrapper may be formed from a laminated material comprising multiple layers. Preferably, the wrapper is formed from an aluminum co-laminate sheet. The use of an aluminum co-laminate sheet advantageously prevents combustion of the aerosol-generating substrate when the aerosol-generating substrate is to be ignited rather than heated in the intended manner.

[0122] The downstream section may have any length. The downstream section can have a length of at least about 10 millimeters. For example, the downstream section may have a length of at least about 15 millimeters, at least about 20 millimeters, at least about 25 millimeters, or at least about 30 millimeters.

[0123] By providing a downstream section with a length longer than the above value, it is possible to advantageously obtain space for the aerosol to cool and condense before it reaches the consumer. This also ensures that the user can stay away from the heat source when the aerosol generating article is used in conjunction with an aerosol generating device.

[0124] The downstream section may have a length of approximately 60 millimeters or less. For example, the downstream section may have a length of approximately 50 millimeters or less, approximately 55 millimeters or less, approximately 40 millimeters or less, or approximately 35 millimeters or less.

[0125] The downstream section may have a length of approximately 10 mm to 60 mm, 15 mm to 50 mm, 20 mm to 55 mm, 25 mm to 40 mm, or 30 mm to 35 mm. For example, the downstream section may have a length of approximately 33 mm.

[0126] The ratio of the length of the downstream section to the length of the element containing the aerosol generating substrate can range from approximately 1.0 to approximately 4.5.

[0127] The ratio of the length of the downstream section to the length of the aerosol generating element is preferably at least about 1.5, more preferably at least about 2.0, and even more preferably at least about 2.5. In a preferred embodiment, the ratio of the length of the downstream section to the length of the aerosol generating element is less than about 4.0, more preferably less than about 3.5, and even more preferably less than about 3.0.

[0128] In some embodiments, the ratio of the length of the downstream section to the length of the aerosol generating element is about 1.5 to about 4.0, preferably about 2.0 to about 3.5, and more preferably about 2.5 to about 3.0.

[0129] In a particularly preferred embodiment, the ratio of the length of the downstream section to the length of the aerosol generating element is approximately 2.75.

[0130] The ratio of the length of the downstream section to the total length of the aerosol-generating article can be approximately 0.1 to 1.5.

[0131] The ratio of the length of the downstream section to the total length of the aerosol-generating article is preferably at least about 0.25, and more preferably at least about 0.50. The ratio of the length of the downstream section to the total length of the aerosol-generating article is preferably less than about 1.25, and more preferably less than about 1.0.

[0132] In some embodiments, the ratio of the length of the downstream section to the total length of the aerosol-generating article is preferably about 0.25 to about 1.25, and more preferably about 0.5 to about 1.0.

[0133] In a particularly preferred embodiment, the ratio of the length of the downstream section to the total length of the aerosol-generating article is approximately 0.73.

[0134] The length of the downstream section can be comprised of the sum of the lengths of the individual components that make up the downstream section.

[0135] The RTD in the downstream section may be approximately 100 mmH2O or less. For example, the RTD in the upstream section may be approximately 50 mmH2O or less, approximately 25 mmH2O or less, approximately 15 mmH2O or less, approximately 10 mmH2O or less, approximately 8 mmH2O or less, approximately 5 mmH2O or less, or approximately 1 mmH2O or less. The RTD in the downstream section will be discussed in more detail below.

[0136] The downstream section may have an unobstructed airflow path from the downstream end of the aerosol generating substrate to the downstream end of the downstream section.

[0137] The unobstructed airflow path from the downstream end of the aerosol generating substrate to the downstream end of the downstream section has a minimum diameter of approximately 0.5 millimeters.

[0138] In the aerosol generating article according to the present invention, the downstream section includes a hollow tube segment.

[0139] By providing hollow tube segments, the desired overall length of the aerosol-generating article can be advantageously provided without increasing the draw resistance to an unacceptable degree.

[0140] The hollow tube can extend from the downstream end to the upstream end of the downstream section. In other words, the hollow tube segment can occupy the entire length of the downstream section. In this case, it will be understood that the above lengths and length ratios for the downstream section are equally applicable to the length of the hollow tubular segment.

[0141] A hollow tube segment may have an inner diameter. A hollow tube segment may have a constant inner diameter along its length. The inner diameter of a hollow tube segment may vary along its length.

[0142] The hollow tube segment may have an inner diameter of at least about 2 millimeters. For example, the hollow tube segment may have an inner diameter of at least about 4 millimeters, at least about 5 millimeters, or at least about 7 millimeters.

[0143] By providing a hollow tube segment having the above-mentioned inner diameter, sufficient rigidity and strength can be advantageously provided to the hollow tube segment.

[0144] The hollow tube segment may have an inner diameter of approximately 10 mm or less. For example, the hollow tube segment may have an inner diameter of approximately 9 mm or less, approximately 8 mm or less, or approximately 7.5 mm or less.

[0145] By providing a hollow tube segment having the above-mentioned inner diameter, the draw resistance of the hollow tubular segment can be advantageously reduced.

[0146] The hollow tube segments may have an inner diameter of approximately 2 mm to 10 mm, approximately 4 mm to 9 mm, approximately 5 mm to 8 mm, or approximately 7 mm to 7.5 mm.

[0147] The hollow tube segment can have an inner diameter of approximately 7.1 millimeters.

[0148] The ratio of the inner diameter to the outer diameter of a hollow tube segment can be at least about 0.8. For example, the ratio can be at least about 0.85, at least about 0.9, or at least about 0.95.

[0149] The ratio between the inner diameter and outer diameter of a hollow tube segment can be approximately 0.99 or less. For example, the ratio between the inner diameter and outer diameter of a hollow tube segment can be approximately 0.98 or less.

[0150] The ratio of the inner diameter to the outer diameter of the hollow tube segment can be approximately 0.97.

[0151] By providing a relatively large inner diameter, the draw resistance of the hollow tubular segment can be advantageously reduced.

[0152] The cavity of the hollow tubular segment may have any cross-sectional shape. The cavity of the hollow tubular segment may have a circular cross-sectional shape.

[0153] Hollow tubular segments can be formed from any material. For example, a hollow tube can contain cellulose acetate tow. When a hollow tubular segment contains cellulose acetate tow, it can have a thickness of about 0.1 mm to about 1 mm. A hollow tubular segment can have a thickness of about 0.5 mm.

[0154] If the hollow tubular segments contain cellulose acetate tow, the cellulose acetate tow can have about 2 to about 4 denier per filament and about 25 to about 40 total denier.

[0155] The hollow tubular segment may contain paper. The hollow tubular segment may contain at least one layer of paper. The paper may be very stiff paper. The paper may be crimped paper, such as crimped heat-resistant paper or crimped parchment paper. The paper may be cardboard. 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.

[0156] If the tubular segment includes paper, the paper may have a thickness of at least about 50 micrometers. For example, the paper may have a thickness of at least about 70 micrometers, at least about 90 micrometers, or at least about 100 micrometers.

[0157] The hollow tubular segment may contain a polymer. For example, the hollow tubular segment may contain a polymer film. The polymer film may contain a cellulose film. The hollow tubular segment may contain low-density polyethylene (LDPE) or polyhydroxyalkanoate (PHA) fibers.

[0158] The downstream section may comprise a modified tubular element. The modified tubular element may be provided in place of a hollow tubular element. The modified tubular element may be provided immediately downstream of the aerosol generating substrate. The modified tubular element may be adjacent to the aerosol generating substrate.

[0159] The modified tubular element may comprise a tubular body defining a cavity extending from a first upstream end of the tubular body to a second downstream end of the tubular body. The modified tubular element may also comprise a folded end that forms a first end wall at the first upstream end of the tubular body. The first end wall can define an opening that allows airflow between the cavity and the outside of the modified tubular element. Preferably, the opening is configured to allow airflow from the aerosol generating substrate through the opening into the cavity.

[0160] The cavity of the tubular body may be substantially empty to allow substantially unlimited airflow along the cavity. The RTD of the modified tubular element may be localized at a specific longitudinal position of the modified tubular element. In particular, the RTD of the modified tubular element may be localized at the first end wall. In this way, the RTD of the modified tubular element can be substantially controlled through a selected configuration of the first end wall and its corresponding opening. The RTD of the modified tubular element (which is essentially the RTD of the first end wall) is of the same magnitude as the RTD of the hollow tubular segment described above.

[0161] The modified tubular element may have any length. The modified tubular element may have a length of about 10 mm to about 60 mm, about 15 mm to about 50 mm, about 20 mm to about 55 mm, about 25 mm to about 40 mm, or about 30 mm to about 35 mm. For example, the modified tubular element may have a length of about 33 mm.

[0162] The modified tubular element has an arbitrary outer diameter (D EThe modified tubular element may have an outer diameter (D) of about 5 mm to about 12 mm, about 6 mm to about 12 mm, or about 7 mm to about 12 mm. E ) may have an outer diameter (D) of about 7.3 mm. The modified tubular element may have an outer diameter (D) of about 7.3 mm. E ) may have.

[0163] The modified tubular element has an arbitrary inner diameter (D I The modified tubular element may have an inner diameter (D) of approximately 2 mm to 10 mm, approximately 4 mm to 9 mm, approximately 5 mm to 8 mm, or 7 mm to 7.5 mm. I ) may have an inner diameter (D) of about 7.1 mm. The modified tubular element may have an inner diameter (D) of about 7.1 mm. I ) may have.

[0164] The modified tubular element may have a peripheral wall of any thickness. The peripheral wall of the modified tubular element may have a thickness of about 0.05 mm to about 0.5 mm. The peripheral wall of the modified tubular element may have a thickness of about 0.1 mm.

[0165] The downstream section may be provided with ventilation. The ventilation is provided so that cooler air from outside the aerosol-generating article can enter the interior of the downstream section.

[0166] Aerosol-generating articles typically have a breathability level of at least about 10 percent, preferably at least about 20 percent.

[0167] In a preferred embodiment, the aerosol-generating article has an air permeability level of at least about 20 percent, 25 percent, or 30 percent. More preferably, the aerosol-generating article has an air permeability level of at least about 35 percent.

[0168] Aerosol-generating articles preferably have a ventilation level of less than approximately 80 percent. More preferably, aerosol-generating articles have a ventilation level of less than approximately 60 percent or less than approximately 50 percent.

[0169] Aerosol-generating articles generally have a ventilation level of approximately 10 percent to 80 percent.

[0170] In some embodiments, the aerosol-generating article has an air permeability level of about 20 percent to about 80 percent, preferably about 20 percent to about 60 percent, and more preferably about 20 percent to about 50 percent. In another embodiment, the aerosol-generating article has an air permeability level of about 25 percent to about 80 percent, preferably about 25 percent to about 60 percent, and more preferably about 25 percent to about 50 percent. In yet another embodiment, the aerosol-generating article has an air permeability level of about 30 percent to about 80 percent, preferably about 30 percent to about 60 percent, and more preferably about 30 percent to about 50 percent.

[0171] In a particularly preferred embodiment, the aerosol-generating article has a permeability level of about 40 percent to about 50 percent. In some particularly preferred embodiments, the aerosol-generating article has a permeability level of about 45 percent.

[0172] While we do not wish to be bound by theory, the inventors have found that the temperature reduction caused by introducing colder outside air into a hollow tubular segment may have a favorable effect on the nucleation and growth of aerosol particles.

[0173] The formation of aerosols from gaseous mixtures containing various chemical species depends on the delicate interactions between nucleation, evaporation, condensation, and even fusion, which explain changes in vapor concentration, temperature, and velocity fields. So-called classical nucleation theory is based on the assumption that some molecules in the gas phase are large enough to remain coherent for a long time with a sufficient probability (e.g., a 50 / 50 probability). These molecules represent a kind of critical threshold molecular cluster in transient molecular aggregates, meaning that smaller molecular clusters generally decompose into the gas phase somewhat more readily, while larger clusters generally grow more readily. 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. The newly nucleated, untreated droplets are assumed to emerge with a certain intrinsic diameter and then grow by several orders of magnitude. This can be facilitated and enhanced by the rapid cooling of the surrounding vapor, which induces condensation. In this regard, it is helpful to keep in mind that evaporation and condensation are two aspects of the same mechanism: the transfer of mass between liquid and gas. Evaporation involves net mass transfer from the liquid droplet phase to the gas phase, while condensation is net mass transfer from the gas phase to the liquid droplet phase. Due to evaporation (or condensation), the liquid droplet shrinks (or grows), but the number of droplets does not change.

[0174] In this scenario (and if the scenario is further complicated by fusion phenomena), the temperature and rate of cooling may play a crucial role in determining how the system responds. Generally, because the nucleation process is typically nonlinear, different cooling rates may lead to significantly different temperature behavior with respect to liquid phase (droplet) formation. While we do not wish to be bound by theory, we assume that cooling can result in a rapid increase in the number of droplet condensations, followed by a short, strong increase in this growth (nucleation burst). This nucleation burst is likely to be more pronounced at lower temperatures. Furthermore, faster cooling rates may favor the early initiation of nucleation. In contrast, decreasing cooling rates are likely to have a favorable effect on the final size that the aerosol droplets eventually reach.

[0175] Therefore, the rapid cooling induced by introducing outside air into the hollow tubular segment can be used to favor the advantageous nucleation and growth of aerosol droplets. However, at the same time, introducing outside air into the hollow tubular segment has the direct disadvantage of diluting the aerosol flow delivered to the consumer.

[0176] The inventors were surprised to find that the dilution effect on aerosols (which can be evaluated by measuring its effect on the delivery of aerosol-forming substances (such as glycerol) contained in the aerosol-generating substrate) is favorably minimized at permeability levels within the aforementioned range. In particular, permeability levels of 25 to 50 percent, and more preferably 28 to 42 percent, were found to lead to particularly satisfactory values ​​of glycerol delivery. At the same time, the degree of nucleation is enhanced, and consequently, the delivery of nicotine and aerosol-forming substances (e.g., glycerol) is enhanced.

[0177] Ventilation into the downstream section can be carried out substantially along the entire length of the downstream section. In this case, the downstream section may include a porous material that allows air to enter the downstream section. For example, if the downstream section comprises a hollow tubular segment, the hollow segment may be formed from a porous material that allows air to enter the interior of the hollow tubular segment. If the downstream section comprises a wrapper, the wrapper may be formed from a porous material that allows air to enter the interior of the hollow tubular segment.

[0178] The downstream section may include a first ventilation zone to provide ventilation to the downstream section. The first ventilation zone comprises a portion of the downstream section, through which a larger volume of air can pass compared to the rest of the downstream section. For example, the first ventilation zone may be a portion of the downstream section having a higher porosity than the rest of the downstream section.

[0179] The first ventilation zone may include a porous portion of the downstream section having at least 5 percent ventilation. For example, the first ventilation zone may include a porous portion of the downstream section having at least 10 percent, at least 20 percent, at least 25 percent, at least 30 percent, or at least 35 percent ventilation.

[0180] The first ventilation zone may include a porous portion of the downstream section having 80 percent or less ventilation. For example, the first ventilation zone may include a porous portion of the downstream section having 60 percent or less ventilation, or less than 50 percent ventilation.

[0181] The first ventilation zone may comprise a porous portion of the downstream section having 10 to 80 percent, 20 to 80 percent, 20 to 60 percent, or 20 to 50 percent ventilation. In another embodiment, the first ventilation zone may comprise a porous portion of the downstream section having 25 to 80 percent, 25 to 60 percent, or 25 to 50 percent ventilation. In yet another embodiment, the first ventilation zone may comprise a porous portion of the downstream section having 30 to 80 percent, 30 to 60 percent, or 30 to 50 percent ventilation.

[0182] The first ventilation zone may comprise a porous portion of the downstream section having 40 to 50 percent ventilation. In some particularly preferred embodiments, the first ventilation zone may comprise a porous portion of the downstream section having 45 percent ventilation.

[0183] The first ventilation zone may include a first perforation line surrounding the downstream section.

[0184] In some embodiments, the ventilation zone may comprise two circumferential rows of perforations. For example, the perforations may be formed online during the manufacture of the aerosol-generating article. Each circumferential row of perforations may comprise about 5 to about 40 perforations, for example, each circumferential row of perforations may comprise about 8 to about 30 perforations.

[0185] If the aerosol-generating article includes a combined plug wrap, the ventilation zone preferably includes at least one corresponding row of circumferential perforations that penetrate a portion of the combined plug wrap. These may be formed online during the manufacture of the smoking article. Preferably, one or more rows of circumferential perforations that penetrate a portion of the combined plug wrap are substantially aligned with one or more rows of perforations that penetrate a downstream section.

[0186] If the aerosol-generating article comprises a strip of chipping paper, and the strip of chipping paper extends across one or more rows of circumferential perforations in the downstream section, the ventilation zone preferably comprises at least one corresponding row of circumferential perforations that penetrate the strip of chipping paper. These may be formed online during the manufacture of the smoking article. Preferably, one or more rows of circumferential perforations that penetrate the strip of chipping paper are substantially aligned with one or more rows of perforations that penetrate the downstream section.

[0187] The first perforation line may comprise at least one perforation having a width of at least about 50 micrometers. For example, the first perforation line may comprise at least one perforation having a width of at least about 65 micrometers, at least about 80 micrometers, at least about 90 micrometers, or at least about 100 micrometers.

[0188] The first perforation line may include at least one perforation having a width of about 200 micrometers or less. For example, the first perforation line may include at least one perforation having a width of about 175 micrometers or less, about 150 micrometers or less, about 125 micrometers or less, or about 120 micrometers or less.

[0189] The first perforation line may have at least one perforation having a width of approximately 50 micrometers to approximately 200 micrometers, approximately 65 micrometers to approximately 175 micrometers, approximately 90 micrometers to approximately 150 micrometers, or approximately 100 micrometers to approximately 120 micrometers.

[0190] When a perforation is formed using laser drilling technology, the width of the perforation can be determined by the focal diameter of the laser.

[0191] The first perforation line may comprise at least one perforation having a length of at least about 400 micrometers. For example, the first perforation line may comprise at least one perforation having a length of at least about 425 micrometers, at least about 450 micrometers, at least about 475 micrometers, or at least about 500 micrometers.

[0192] The first perforation line may comprise at least one perforation having a length of about 1 millimeter or less. For example, the first perforation line may comprise at least one perforation having a length of about 950 micrometers or less, about 900 micrometers or less, about 850 micrometers or less, or about 800 micrometers or less.

[0193] The first perforation line may have at least one perforation having a length of approximately 400 micrometers to approximately 1 millimeter, approximately 425 micrometers to approximately 950 micrometers, approximately 450 micrometers to approximately 900 micrometers, approximately 475 micrometers to approximately 850 micrometers, or approximately 500 micrometers to approximately 800 micrometers.

[0194] The first perforation line may comprise at least one perforation having an opening area of ​​at least about 0.01 square millimeters. For example, the first perforation line may comprise at least one perforation having an opening area of ​​at least about 0.02 square millimeters, at least about 0.03 square millimeters, or at least about 0.05 square millimeters.

[0195] The first perforation line may include at least one perforation having an opening area of ​​about 0.5 square millimeters or less. For example, the first perforation line may include at least one perforation having an opening area of ​​about 0.3 square millimeters or less, about 0.25 square millimeters or less, or about 0.1 square millimeters or less.

[0196] The first perforation line may include at least one perforation having an opening area of ​​approximately 0.01 square millimeters to approximately 0.5 square millimeters, approximately 0.02 square millimeters to approximately 0.3 square millimeters, approximately 0.03 square millimeters to approximately 0.25 square millimeters, or approximately 0.05 square millimeters to approximately 0.1 square millimeters. The first perforation line may include at least one perforation having an opening area of ​​approximately 0.05 square millimeters to approximately 0.096 square millimeters.

[0197] As described above, the aerosol-generating article may be provided with a wrapper that surrounds at least a portion of the downstream section, and the first ventilation zone may be provided with a porous portion of the wrapper.

[0198] The wrapper may be a paper wrapper, and the first ventilation zone may include a portion of porous paper.

[0199] As described above, the downstream section may include a hollow tube spaced apart from the downstream end of the aerosol generating substrate. In this case, the hollow tube may be connected to the aerosol generating substrate by a paper wrapper. The wrapper may be a porous paper wrapper. In this case, the first ventilation zone may include a portion of the porous paper wrapper that covers the space between the downstream end of the aerosol generating substrate and the upstream end of the hollow tube. In this case, the upstream end of the first ventilation zone abuts against the downstream end of the aerosol generating substrate, and the downstream end of the first ventilation zone abuts against the upstream end of the hollow tube.

[0200] The porous portion of the wrapper that forms the first ventilation zone may have a lower basis weight than the basis weight of the portion of the wrapper that does not form part of the first ventilation zone.

[0201] The porous portion of the wrapper that forms the first ventilation zone may have a thickness lower than the thickness of the portion of the wrapper that does not form part of the first ventilation zone.

[0202] The upstream end of the first ventilation zone may be less than 10 millimeters from the downstream end of the aerosol generating substrate.

[0203] For example, the upstream end of the first ventilation zone may be less than 8 millimeters, less than 5 millimeters, less than 3 millimeters, or less than 1 millimeter from the downstream end of the aerosol generating substrate.

[0204] The upstream end of the first ventilation zone can be aligned longitudinally with the downstream end of the aerosol generating substrate.

[0205] The upstream end of the first ventilation zone can be located at less than 25 percent of the path along the length of the downstream element from the downstream end of the aerosol generating substrate. For example, the upstream end of the first ventilation zone can be located at less than 20 percent, less than 18 percent, less than 15 percent, less than 10 percent, less than 5 percent, or less than 1 percent of the path along the length of the downstream element from the downstream end of the aerosol generating substrate.

[0206] The downstream end of the first ventilation zone can be located at less than 30 percent of the path along the length of the downstream element from the downstream end of the aerosol generating substrate. For example, the downstream end of the first ventilation zone can be located at less than 25 percent, less than 20 percent, less than 18 percent, less than 15 percent, less than 10 percent, or less than 5 percent of the path along the length of the downstream element from the downstream end of the aerosol generating substrate.

[0207] The downstream end of the first ventilation zone may be less than 10 millimeters from the downstream end of the aerosol generating substrate. In other words, the first ventilation zone can be entirely located within 10 millimeters of the aerosol generating substrate.

[0208] For example, the downstream end of the first ventilation zone may be 8 millimeters or less, 5 millimeters or less, or 3 millimeters or less from the downstream end of the aerosol generating substrate.

[0209] The first ventilation zone may be located anywhere along the length of the downstream section. The downstream end of the first ventilation zone can be located no more than approximately 25 millimeters from the downstream end of the aerosol-generating article. For example, the first ventilation zone can be located no more than approximately 20 millimeters from the downstream end of the aerosol-generating article.

[0210] As outlined above, by arranging the first ventilation zone, it is advantageous to prevent the first ventilation zone from being blocked when an aerosol-generating article is inserted into the aerosol generator.

[0211] The downstream end of the first ventilation zone can be positioned at least about 8 millimeters from the downstream end of the aerosol-generating article. For example, the downstream end of the first ventilation zone can be positioned at least about 10 millimeters, at least 12 millimeters, or at least about 15 millimeters from the downstream end of the aerosol-generating article.

[0212] As outlined above, by positioning the first ventilation zone, it is advantageous to prevent the first ventilation zone from being blocked by the user's mouth or lips while the aerosol-generating article is in use.

[0213] The downstream end of the first ventilation zone can be positioned approximately 8 mm to 25 mm, 10 mm to 25 mm, or 15 mm to 20 mm from the downstream end of the aerosol generating article. The downstream end of the first ventilation zone can also be positioned approximately 18 mm from the downstream end of the aerosol generating article.

[0214] The upstream end of the first ventilation zone can be positioned at least about 20 millimeters from the upstream end of the aerosol-generating article. For example, the upstream end of the first ventilation zone can be positioned at least about 25 millimeters from the upstream end of the aerosol-generating article.

[0215] As outlined above, by arranging the first ventilation zone, it is advantageous to prevent the first ventilation zone from being blocked when an aerosol-generating article is inserted into the aerosol generator.

[0216] The upstream end of the first ventilation zone can be positioned no more than 37 millimeters from the upstream end of the aerosol-generating article. For example, the upstream end of the first ventilation zone can be positioned no more than approximately 30 millimeters from the upstream end of the aerosol-generating article.

[0217] As outlined above, by positioning the first ventilation zone, it is advantageous to prevent the first ventilation zone from being blocked by the user's mouth or lips while the aerosol-generating article is in use.

[0218] The upstream end of the first ventilation zone can be positioned approximately 20 to 37 millimeters, or approximately 25 to 30 millimeters, from the upstream end of the aerosol-generating article. The upstream end of the first ventilation zone can be positioned approximately 27 millimeters from the downstream end of the aerosol-generating article.

[0219] The first ventilation zone may have any length. The first ventilation zone may have a length of at least 0.5 millimeters. In other words, the longitudinal distance between the downstream end and the upstream end of the first ventilation zone is at least 0.5 millimeters. For example, the first ventilation zone may have a length of at least 1 millimeter, at least 2 millimeters, at least 5 millimeters, or at least 8 millimeters.

[0220] The first ventilation zone may have a length of 10 millimeters or less. For example, the first ventilation zone may have a length of 8 millimeters or less, or 5 millimeters or less.

[0221] The first ventilation zone may have a length of approximately 0.5 mm to approximately 10 mm. For example, the first ventilation zone may have a length of approximately 1 mm to approximately 8 mm, or approximately 2 mm to approximately 5 mm.

[0222] In addition to the hollow tubular element and the aerosol generating element, the aerosol generating article may further comprise additional elements or components, such as a filter segment or a mouthpiece segment. Preferably, the downstream section of the aerosol generating article may comprise additional elements or components, such as a filter segment or a mouthpiece segment, in addition to the hollow tubular element.

[0223] Such additional elements may be positioned downstream of the hollow tubular element. They may also be positioned immediately downstream of the hollow tubular element. Furthermore, they may be positioned between the aerosol generating element and the hollow tubular element. Such additional elements may extend from the downstream end of the hollow tubular element to the mouth end of the aerosol generating article, or to the downstream end of the downstream section. Such additional elements are preferably downstream elements or segments. These additional elements may be filter elements or segments, or mouthpiece segments. Such additional elements may form part of the downstream section of the aerosol generating article of this disclosure. These additional elements may be axially aligned with the remaining components of the aerosol generating article, such as the aerosol generating element and the hollow tubular element. Additionally, the additional elements may have a diameter similar to the outer diameter of the hollow tubular element, the diameter of the aerosol generating element, or the diameter of the aerosol generating article.

[0224] The aerosol-generating articles of this disclosure preferably include a wrapper surrounding the downstream section (or components of the downstream section). Such a wrapper may be an outer chipping wrapper surrounding the downstream section and a portion of the aerosol-generating element so that the downstream section is attached to the aerosol-generating element.

[0225] The downstream section of the aerosol-generating article of this disclosure can define a concave cavity.

[0226] The “additional elements” described above may also be referred to in this disclosure as the “first section” or “first segment” of the “downstream section.” The terms “first segment” or “additional elements” may also be referred to in this disclosure as “mouthpiece segment,” “retaining segment,” “downstream segment,” “mouthpiece element,” “downstream element,” “retaining element,” “filter element,” or “filter segment,” or “downstream plug element.” The term “mouthpiece” may refer to an element of an aerosol-generating article located downstream of the aerosol-generating element of the article, preferably near the mouth end of the article.

[0227] Unless otherwise specified, the draw resistance (RTD) of a component or aerosol-generating article is measured according to 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 typically refer to measurements performed according to ISO 6565-2015 under test conditions of a volumetric flow rate of approximately 17.5 ml / second at the output or downstream end of the component being measured, at a temperature of approximately 22 degrees Celsius, a pressure of approximately 101 kPa (approximately 760 Torr), and a relative humidity of approximately 60%.

[0228] The draw resistance per unit length of a specific component (or element) of an aerosol-generating article, such as a downstream section, a first section, or a first segment, can be calculated by dividing the measured draw resistance of the component by the total axial length of the component. RTD per unit length refers to the pressure required to force air through a unit length of the component. Throughout this disclosure, unit length refers to a length of 1 mm. Therefore, to derive the RTD per unit length of a particular part, a test specimen of a specific length of the component, for example, 15 mm, can be used for measurement. The RTD of such specimens is measured according to ISO 6565-2015. For example, if the measured RTD is approximately 15 mmH2O, then the RTD per unit length of the component is approximately 1 mmH2O per mm. The RTD per unit length of a component depends, among other factors, particularly the structural properties of the material used in the component, as well as the cross-sectional shape or external shape of the component.

[0229] The relative RTD per unit length of the downstream section, or the RTD itself, may be approximately 0 mmH2O to approximately 3 mmH2O per mm. Alternatively, the RTD per unit length of the downstream section may be approximately 0 mmH2O to approximately 2.5 mmH2O per mm. Alternatively, the RTD per unit length of the downstream section may be approximately 0 mmH2O to approximately 2 mmH2O per mm. The RTD per unit length of the downstream section may be approximately 0 mmH2O to approximately 1 mmH2O per mm. The RTD per unit length of the downstream section may be approximately 0 mmH2O to approximately 0.75 mmH2O per mm.

[0230] As described above, the relative RTD or RTD per unit length of the downstream section may be approximately 0 mmH2O to approximately 3 mmH2O per mm. Alternatively, the RTD per unit length of the downstream section may be greater than approximately 0 mmH2O and less than approximately 2.5 mmH2O per mm. Alternatively, the RTD per unit length of the downstream section may be greater than approximately 0 mmH2O and less than approximately 2 mmH2O per mm. The RTD per unit length of the downstream section may be greater than approximately 0 mmH2O and less than approximately 1 mmH2O per mm. The RTD per unit length of the downstream section may be greater than approximately 0 mmH2O and less than approximately 0.75 mmH2O per mm.

[0231] The RTD per unit length of the downstream section may be approximately 0 mmH2O or more per mm. Therefore, the RTD per unit length of the downstream section may be approximately 0 mmH2O to approximately 3 mmH2O per mm. Alternatively, the RTD per unit length of the downstream section may be approximately 0 mmH2O to approximately 2.5 mmH2O per mm. Alternatively, the RTD per unit length of the downstream section may be approximately 0 mmH2O to approximately 2 mmH2O per mm. The RTD per unit length of the downstream section may be approximately 0 mmH2O to approximately 1 mmH2O per mm. The RTD per unit length of the downstream section may be approximately 0 mmH2O to approximately 0.75 mmH2O per mm.

[0232] The draw resistance of the downstream section may be approximately 0 mmH2O or more and less than approximately 10 mmH2O. The draw resistance of the downstream section may be greater than 0 mmH2O and less than approximately 5 mmH2O. The draw resistance of the downstream section may be greater than 0 mmH2O and less than approximately 2 mmH2O. The draw resistance of the downstream section may be greater than 0 mmH2O and less than approximately 1 mmH2O.

[0233] The upstream end of the aerosol-generating article can be defined by a wrapper. Providing a wrapper at the upstream end of the aerosol-generating article is advantageous because it allows the aerosol-forming substrate to be retained on the article. This feature is also advantageous because it prevents the user from directly contacting the aerosol-generating substrate.

[0234] The wrapper may be mechanically closed at the upstream end of the aerosol-generating article. This can be achieved by folding or twisting the wrapper. The upstream end of the aerosol-generating article may be closed using adhesive.

[0235] The wrapper defining the upstream end of the aerosol-generating article may be formed from the same material piece as the wrapper surrounding at least a portion of the downstream section.

[0236] This provision advantageously simplifies the manufacture of aerosol-generating articles because only one piece of wrapper material may be required. Furthermore, the use of one piece of wrapper material eliminates the need for seams to connect two pieces of wrapper material. This advantageously simplifies manufacturing. The absence of seams also advantageously prevents or reduces leakage of any aerosol-generating substrate from the aerosol-generating article.

[0237] The aerosol generating article of the present invention may further include an upstream element upstream of the aerosol generating substrate. The upstream element may extend from the upstream end of the aerosol generating substrate to the upstream end of the aerosol generating article. The upstream element may abut against the upstream end of the aerosol generating article. The upstream element may be referred to as an upstream section.

[0238] An aerosol generating article may be provided with an air intake at its upstream end. If the aerosol generating article includes an upstream element, the air intake may be provided through the upstream element. Air entering through the air intake may pass through the aerosol generating substrate to generate a mainstream aerosol.

[0239] The upstream section may have a high RTD.

[0240] In embodiments of the present invention where the downstream section has a relatively low RTD, for example, less than about 10 mmH2O, providing an upstream element with a relatively high RTD is advantageous in that it can provide an acceptable overall RTD without requiring a high RTD element such as a filter downstream of the aerosol generating substrate. During use, air enters the aerosol generating article through the upstream end of the upstream section, passes through the upstream section, and enters the aerosol generating substrate. The air then enters and passes through the downstream section and then exits from the downstream end of the downstream section.

[0241] The RTDs in the upstream section may account for the majority of the RTDs in the entire aerosol-generating article.

[0242] The ratio of the RTD of the upstream section to the RTD of the downstream section may be greater than 1. For example, the RTD of the downstream section may be greater than approximately 2, greater than approximately 5, greater than approximately 8, greater than approximately 10, greater than approximately 15, greater than approximately 20, or greater than approximately 50.

[0243] The RTD in the upstream section may be at least about 5 mmH2O. For example, the RTD in the upstream section may be at least about 10 mmH2O, at least about 12 mmH2O, at least about 15 mmH2O, or at least about 20 mmH2O.

[0244] The RTD in the upstream section may be approximately 80 mmH2O or less. For example, the RTD in the upstream section may be approximately 70 mmH2O or less, approximately 60 mmH2O or less, approximately 50 mmH2O or less, or approximately 40 mmH2O or less.

[0245] The RTD of the upstream section may be approximately 5 mmH2O to 80 mmH2O. For example, the RTD of the upstream section may be approximately 10 mmH2O to 70 mmH2O, approximately 12 mmH2O to 60 mmH2O, approximately 15 mmH2O to 50 mmH2O, or approximately 20 mmH2O to 40 mmH2O.

[0246] The upstream section can advantageously prevent direct physical contact with the upstream end of the aerosol generating substrate. Specifically, if the aerosol generating substrate includes a susceptor element, the upstream section can prevent direct physical contact with the upstream end of the susceptor element. This helps 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. Furthermore, the presence of the upstream section can be advantageous, for example, if the substrate contains particulate plant material, as it helps prevent any loss of the substrate.

[0247] The upstream section can also provide an improved appearance to the upstream end of the aerosol-generating article. Furthermore, if desired, the upstream section can be used to provide information about the aerosol-generating article, such as the brand, flavor, content, or details of the aerosol generator in which the article is intended to be used.

[0248] The upstream section may include a porous plug element. The porous plug element may have a porosity of at least about 50 percent in the longitudinal direction of the aerosol-generating article. More preferably, the porous plug element has a porosity of about 50 percent to about 90 percent in the longitudinal direction. The porosity of the porous plug element in the longitudinal direction is determined by the ratio of the cross-sectional area of ​​the material forming the porous plug element to the internal cross-sectional area of ​​the aerosol-generating article at the location of the porous plug element.

[0249] The porous plug element may be made of a porous material or may have multiple openings. This can be achieved, for example, by laser drilling. Preferably, the multiple openings are uniformly distributed across the cross-section of the porous plug element.

[0250] The porosity or permeability of the upstream section can be advantageously varied to provide the desired overall draw resistance of the aerosol-generating article.

[0251] In another embodiment, the upstream section may be formed from a material that is impermeable to air. In such embodiments, the aerosol-generating article may be configured so that air flows into the aerosol-generating element through a suitable ventilation means provided within the wrapper.

[0252] The upstream section may be made of any material suitable for use in an aerosol-generating article. For example, the upstream element may include a material plug. Suitable materials for forming the upstream section include filter materials, ceramics, polymer materials, cellulose acetate, cardboard, zeolite, or aerosol-generating substrates. The upstream section preferably includes a plug containing cellulose acetate.

[0253] If the upstream section includes a material plug, the downstream end of the material plug may be around the upstream end of the aerosol-generating substrate. For example, the upstream section may include a plug containing cellulose acetate that abuts the upstream end of the aerosol-generating substrate. This can be advantageous as it may help to hold the aerosol-generating substrate in place.

[0254] If the upstream section includes a material plug, the downstream end of the material plug may be separated from the upstream end of the aerosol generating substrate by a gap. The upstream element may include a plug containing a fibrous filter material.

[0255] The upstream section is preferably formed from a heat-resistant material. For example, the upstream section is preferably formed from a material that can withstand temperatures up to 350 degrees Celsius. This ensures that the upstream section is not adversely affected by the heating means used to heat the aerosol generating substrate.

[0256] The upstream section preferably has a diameter approximately equal to the diameter of the aerosol-generating article.

[0257] The upstream section may have a length of at least about 1 millimeter. For example, the upstream section may have a length of at least about 2 millimeters, at least about 4 millimeters, or at least about 6 millimeters.

[0258] The upstream section may have a length of approximately 15 millimeters or less. For example, the upstream section may have a length of approximately 12 millimeters or less, approximately 10 millimeters or less, or approximately 8 millimeters or less.

[0259] The upstream section may have a length of approximately 1 mm to 15 mm. For example, the upstream section may have a length of approximately 2 mm to 12 mm, approximately 4 mm to 10 mm, or approximately 6 mm to 8 mm.

[0260] The length of the upstream section can be advantageously varied to provide the desired overall length of the aerosol-generating article. For example, if it is desirable to reduce the length of one of the other components of the aerosol-generating article, the length of the upstream section can be increased to maintain the same overall length of the article.

[0261] The upstream section preferably has a substantially homogeneous structure. For example, the upstream section may have a substantially homogeneous texture and appearance. The upstream section may have, for example, a continuous, regular surface throughout its entire cross-section. The upstream section may not have, for example, recognizable symmetry.

[0262] The upstream section may include a second tubular element. The second tubular element may be provided instead of the upstream element. The second tubular element may be provided immediately upstream of the aerosol generating substrate. The second tubular element may be in contact with the aerosol generating substrate.

[0263] The second tubular element may comprise a tubular body that defines a cavity extending from a first upstream end of the tubular body to a second downstream end of the tubular body. The second tubular element may also comprise a folded end that forms a first end wall at the first upstream end of the tubular body. The first end wall can define an opening that allows airflow between the cavity and the outside of the second tubular element. Preferably, air can flow from the cavity through the opening into the aerosol generating substrate.

[0264] A second tubular element may have a second end wall at a second end of its tubular body. This second end wall can be formed by folding one end of the second tubular element at the second downstream end of the tubular body. The second end wall can define an opening that allows airflow between the cavity and the outside of the second tubular element. In the case of the second end wall, the opening can be configured so that air can flow from outside the aerosol generating article through the opening into the cavity. Thus, the opening can provide a conduit through which air can be drawn into the aerosol generating article and through the aerosol generating substrate.

[0265] The upstream section is preferably surrounded by a wrapper. The wrapper surrounding the upstream section is preferably a rigid plug wrap, for example, a plug wrap having a basis weight of at least about 80 grams (gsm) per square meter, or at least about 100 gsm, or at least about 110 gsm. This provides structural rigidity to the upstream section.

[0266] As described above, the disclosure also relates to an aerosol generating system comprising an aerosol generating device having a distal end and an oral end. The aerosol generating device comprises a body. The body 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 comprises a heating element or heater for heating the aerosol generating substrate when the aerosol generating article is received in the device cavity.

[0267] The device cavity may be referred to as the heating chamber of the aerosol generator. The device cavity may extend between a distal end and a mouth end or proximal end. The distal end of the device cavity may be a closed end, and the mouth end or proximal end may be an open end. The aerosol generating article may be inserted into the device cavity or heating chamber through the open end of the device cavity. The device cavity may be cylindrical in shape to accommodate the same shape as the aerosol generating article.

[0268] The expression "internal acceptance" may refer to the fact that a component or element is fully or partially accepted within another component or element. For example, the expression "an aerosol-generating article is accepted within the device cavity" means that the aerosol-generating article is fully or partially accepted within the device cavity of the aerosol-generating article. When an aerosol-generating article is accepted within the device cavity, it may abut against the distal end of the device cavity. When an aerosol-generating article is accepted within the device cavity, it may be substantially close to the distal end of the device cavity. The distal end of the device cavity may be defined by an end wall.

[0269] The length of the device cavity may be approximately 10 mm to 50 mm. The length of the device cavity may be approximately 20 mm to 40 mm. The length of the device cavity may be approximately 25 mm to 30 mm. 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.

[0270] The diameter of the device cavity may be approximately 4 mm to 50 mm. The diameter of the device cavity may be approximately 4 mm to 30 mm. The diameter of the device cavity may be approximately 5 mm to 15 mm. The diameter of the device cavity may be approximately 6 mm to 12 mm. The diameter of the device cavity may be approximately 7 mm to 10 mm. The diameter of the device cavity may be approximately 7 mm to 8 mm.

[0271] The diameter of the device cavity may be the same as or larger than the diameter of the aerosol generating article. The diameter of the device cavity may be the same as the diameter of the aerosol generating article in order to establish a tight fit with the aerosol generating article.

[0272] The device cavity may be configured to establish a tight fit with the aerosol generating article received within the device cavity. A tight fit may refer to a sliding fit. The aerosol generating device may include peripheral walls. Such peripheral walls may define the device cavity or heating chamber. Peripheral walls defining the device cavity may be configured to engage in a tight fit with the aerosol generating article received within the device cavity such that, when received within the device, there is substantially no gap or empty space between the peripheral wall defining the device cavity and the aerosol generating article.

[0273] Such airtight fittings can establish an airtight fit or configuration between the device cavity and the aerosol-generating article received therein.

[0274] In such an airtight configuration, there is virtually no gap or empty space between the surrounding walls that define the device cavity and the aerosol-generating article through which air flows.

[0275] 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.

[0276] The aerosol generator may include an airflow channel extending between a channel inlet and a channel outlet. The airflow channel may be configured to establish fluid communication between the inside of the device cavity and the outside of the aerosol generator. The airflow channel of the aerosol generator may be defined within the housing of the aerosol generator to enable fluid communication between the inside of the device cavity and the outside of the aerosol generator. When an aerosol-generating article is received in the device cavity, the airflow channel may be configured to provide air flowing into the article to deliver the generated aerosol to a user who draws it out from the mouth end of the article.

[0277] The airflow channel of the aerosol generator may be defined within or by the peripheral wall of the housing of the aerosol generator. In other words, the airflow channel of the aerosol generator may be defined within the thickness of the peripheral wall, 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.

[0278] The airflow channel of an aerosol generator may extend from an inlet located at the mouth or proximal end of the aerosol generator to an outlet located away from the mouth end of the device. The airflow channel may extend along a direction parallel to the longitudinal axis of the aerosol generator.

[0279] The aerosol generator may include an elongated heater (or heating element) positioned to be inserted into the aerosol generating article when the article is housed within the device cavity. The elongated heater may be positioned together with the device cavity. The elongated heater may extend into the device cavity. Alternative heating arrangements will be discussed further below.

[0280] The heater can be any suitable type of heater. The heater is preferably an external heater.

[0281] When the heater is housed within the aerosol generator, it is preferable that it can heat the aerosol-generating article from the outside. Such an external heater can surround the aerosol-generating article when inserted into or received within the aerosol generator.

[0282] In some embodiments, the heater is positioned to heat the outer surface of the aerosol-forming substrate. In some embodiments, the heater is positioned to be inserted into the aerosol-forming substrate when the aerosol-forming substrate is received into the cavity. The heater may be located within the apparatus cavity or heating chamber.

[0283] The heater may comprise at least one heating element. The at least one heating element can be any suitable type of heating element. In some embodiments, the device comprises only one heating element. In some embodiments, the device comprises multiple heating elements. The heater may include at least one resistive heating element. Preferably, the heater includes multiple resistive heating elements. Preferably, the resistive heating elements are electrically connected in a parallel arrangement. Advantageously, providing multiple resistive heating elements electrically connected in a parallel arrangement can facilitate the 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 can facilitate reducing or minimizing the physical size of the power supply.

[0284] Suitable materials for forming at least one resistance heating element include, but are not limited to, semiconductors such as doped ceramics, "conductive" ceramics (e.g., molybdenum disilide), carbon, graphite, metals, metal alloys, and composite materials made of ceramic and metal materials. Such composite materials may include doped or undoped ceramics. A suitable example of a doped ceramic is doped silicon carbide. Suitable examples of metals include titanium, zirconium, tantalum, and platinum group metals. Suitable examples of metal alloys include stainless steel, nickel-containing, cobalt-containing, chromium-containing, aluminum-containing, titanium-containing, zirconium-containing, hafnium-containing, niobium-containing, molybdenum-containing, tantalum-containing, tungsten-containing, tin-containing, gallium-containing, manganese-containing, and iron-containing alloys, as well as nickel, iron, cobalt, stainless steel-based superalloys, Timetal®, and iron-manganese-aluminum alloys.

[0285] In some embodiments, at least one resistive heating element includes one or more stamped portions of an electrically resistive material (such as stainless steel). Alternatively, at least one resistive heating element may include a heating wire or filament (e.g., Ni-Cr (nickel-chromium), platinum, tungsten, or alloy wire).

[0286] In some embodiments, at least one heating element includes an electrically insulated substrate, and at least one resistance heating element is provided on an electrically insulated substrate.

[0287] The electrically insulated substrate may include any suitable material. For example, the electrically insulated substrate may include one or more of paper, glass, ceramic, anodized metal, coated metal, and polyimide. The ceramic may include mica, alumina (Al2O3), or zirconia (ZrO2). The electrically insulated substrate preferably has a thermal conductivity of about 40 watts / meter Kelvin or less, preferably about 20 watts / meter Kelvin or less, and ideally about 2 watts / meter Kelvin or less.

[0288] The heater may comprise a heating element including a rigid, electrically insulated substrate having one or more conductive tracks or wires arranged on its surface. Depending on the size and shape of the electrically insulated substrate, the heater may be directly inserted into the aerosol-forming substrate. If the electrically insulated substrate is not sufficiently rigid, the heating element may include further reinforcing means. An electric current may pass through one or more conductive tracks to heat the heating element and the aerosol-forming substrate.

[0289] In some embodiments, the heater comprises an induction heating arrangement. The induction heating arrangement may comprise an inductor coil and a power supply configured to supply a high-frequency oscillating current to the inductor coil. As used herein, a high-frequency oscillating current means an oscillating current having a frequency of 500 kHz to 30 MHz. Advantageously, the heater may include a DC / AC inverter for converting the DC current supplied by the DC power supply into an AC current. The inductor coil may be arranged to generate a high-frequency oscillating electromagnetic field upon receiving a high-frequency oscillating current from the power supply. The inductor coil may be arranged to generate a high-frequency oscillating electromagnetic field within a device cavity. In some embodiments, the inductor coil may substantially enclose the device cavity. The inductor coil may extend at least partially along the length of the device cavity.

[0290] The heater may include an inductive heating element. The inductive heating element may be a susceptor element. As used herein, the term “susceptor element” refers to an element comprising a material having the ability to convert electromagnetic energy into heat. When a susceptor element is located in an alternating electromagnetic field, the susceptor is heated. The heating of the susceptor element may be the result of at least one of hysteresis losses and eddy currents induced within the susceptor, depending on the electrical properties and magnetism of the susceptor material.

[0291] The susceptor element may be positioned such that when an aerosol-generating article is received in the cavity of the aerosol generator, the oscillating electromagnetic field generated by the inductor coil induces a current within the susceptor element, thereby heating the susceptor element. In these embodiments, the aerosol generator is preferably capable of generating a fluctuating electromagnetic field having a magnetic field strength (H-field strength) of 1 to 5 kiloamperes / meter (kA / m), preferably 2 to 3 kA / m, for example about 2.5 kA / m. The electrically operated aerosol generator is preferably capable of generating a fluctuating electromagnetic field with a frequency of 1 to 30 MHz, for example 1 to 10 MHz, for example 5 to 7 MHz.

[0292] In some embodiments, the susceptor element is located within the aerosol-generating article. In these embodiments, the susceptor element is preferably located in contact with the aerosol-forming substrate. The susceptor element may be located within the aerosol-forming substrate.

[0293] In some embodiments, the susceptor element is located within the aerosol generator. In these embodiments, the susceptor element may be located within a cavity. The aerosol generator may include only one susceptor element. The aerosol generator may comprise multiple susceptor elements.

[0294] In some embodiments, the susceptor element is positioned to heat the outer surface of the aerosol-forming substrate. In some embodiments, the susceptor element is positioned to be inserted into the aerosol-forming substrate when the aerosol-forming substrate is received into the cavity.

[0295] The susceptor element may comprise any suitable material. The susceptor element may be formed from any material that can be induction heated to a temperature sufficient to release volatile compounds from an aerosol-forming substrate. Suitable materials for an elongate susceptor element include graphite, molybdenum, silicon carbide, stainless steel, niobium, aluminum, nickel, nickel-containing compounds, titanium, and composites of metallic materials. Some susceptor elements comprise metal or carbon. Advantageously, the susceptor element may comprise or consist of a ferromagnetic material, for example ferromagnetic alloys such as ferritic iron, ferromagnetic steel or stainless steel, ferromagnetic particles, and ferrite. A suitable susceptor element may be or comprise aluminum. The susceptor element preferably comprises 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 elongate susceptor elements may be heated to temperatures in excess of about 250 degrees Celsius.

[0296] The susceptor element may comprise a non-metallic core having a metal layer arranged on the non-metallic core. For example, the susceptor element may comprise a ceramic core or a metal track formed on an outer surface of a substrate.

[0297] In some embodiments, the aerosol-generating device may comprise at least one resistive heating element and at least one inductive heating element. In some embodiments, the aerosol-generating device may comprise a combination of a resistive heating element and an inductive heating element.

[0298] In use, the heater may be controlled to operate within a defined operating temperature range below a 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.

[0299] Preferably, the heater's operating temperature range may be between approximately 150°C and approximately 200°C. More preferably, the heater's operating temperature range may be between approximately 180°C and approximately 200°C. Specifically, as described throughout this disclosure, it has been found that optimal and consistent aerosol delivery can be achieved when using an aerosol generating article with a relatively low RTD (e.g., less than 10 mmH2O) and an aerosol generating device having an external heater with an operating temperature range of approximately 180°C to approximately 200°C.

[0300] In embodiments where the aerosol-generating article has a ventilation zone located along a downstream section or a hollow tubular element, the ventilation zone may be positioned to be exposed when the aerosol-generating article is housed within a device cavity.

[0301] The aerosol generator may be equipped with a power supply. The power supply may be a DC power supply. In some embodiments, the power supply is a battery. The power supply 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 supply may be another form of charge storage device, such as a capacitor. The power supply may require recharging and may have a capacity that allows for sufficient energy storage for one or more user operations, such as one or more aerosol generation experiences. For example, the power supply may have a capacity sufficient to allow continuous heating of the aerosol-forming substrate for about six minutes, or a multiple of six minutes, corresponding to the typical time it takes to smoke one conventional cigarette. In another embodiment, the power supply may have a capacity sufficient to allow a predetermined number of puffs or discontinuous activation of the heater.

[0302] The aerosol-generating article may have a length of approximately 35 mm to approximately 100 mm.

[0303] The total length of the aerosol generating article according to the present invention is preferably at least about 38 millimeters. More preferably, the total length of the aerosol generating article according to the present invention is at least about 40 millimeters. Even more preferably, the total length of the aerosol generating article according to the present invention is at least about 42 millimeters.

[0304] The total length of the aerosol generating article according to the present invention is preferably 70 millimeters or less. More preferably, the total length of the aerosol generating article according to the present invention is preferably 60 millimeters or less. Even more preferably, the total length of the aerosol generating article according to the present invention is preferably 50 millimeters or less.

[0305] In some embodiments, 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. In other embodiments, 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. In further embodiments, 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. In an exemplary embodiment, the total length of the aerosol generating article is about 45 mm.

[0306] The aerosol-generating article has an outer diameter of at least 5 mm. Preferably, the aerosol-generating article has an outer diameter of at least 6 mm. More preferably, the aerosol-generating article has an outer diameter of at least 7 mm.

[0307] The aerosol generating article preferably has an outer diameter of about 12 mm or less. More preferably, the aerosol generating article has an outer diameter of about 10 mm or less. Even more preferably, the aerosol generating article has an outer diameter of about 8 mm or less.

[0308] In some embodiments, the aerosol-generating article has an outer diameter of about 5 mm to about 12 mm, preferably about 6 mm to about 12 mm, and more preferably about 7 mm to about 12 mm. In other embodiments, the aerosol-generating article has an outer diameter of about 5 mm to about 10 mm, preferably about 6 mm to about 10 mm, and more preferably about 7 mm to about 10 mm. In further embodiments, the aerosol-generating article has an outer diameter of about 5 mm to about 8 mm, preferably about 6 mm to about 8 mm, and more preferably about 7 mm to about 8 mm.

[0309] One or more components of the aerosol-generating article may be individually surrounded by a wrapper. In a preferred embodiment, all components of the aerosol-generating article are individually surrounded by their own wrappers. Preferably, at least one component of the aerosol-generating article is wrapped in a hydrophobic wrapper.

[0310] The term "hydrophobic" refers to a surface that exhibits water-repellent properties. One useful way to determine this is by measuring the water contact angle. The water contact angle is the angle conventionally measured through a liquid, where the liquid / vapor interface intersects with the solid surface. This quantifies the wettability of a solid surface by a liquid via Young's equation. Hydrophobicity or the water contact angle may also be determined using the TAPPI T558 test method, and the result is expressed as the interfacial contact angle and reported in degrees, which can range from approximately 0 to approximately 180 degrees.

[0311] In a preferred embodiment, the hydrophobic wrapper comprises a paper layer having a water contact angle of at least about 30 degrees, preferably at least about 35 degrees, or at least about 40 degrees, or at least about 45 degrees.

[0312] By way of example, the paper layer may comprise PVOH (polyvinyl alcohol) or silicone. PVOH may be applied to the paper layer as a surface coating, or the paper layer may comprise a surface treatment comprising PVOH or silicone.

[0313] In a particularly preferred embodiment, the aerosol-generating article according to the invention comprises, in a linear sequential arrangement, an aerosol-generating element comprising a rod provided with an aerosol-generating substrate, and a hollow tubular element positioned immediately downstream of the aerosol-generating element.

[0314] More particularly, the hollow tubular element may abut the aerosol-generating element.

[0315] The aerosol-generating article has a substantially cylindrical shape and an outer diameter of about 7.3 millimeters.

[0316] The hollow tubular element is in the form of a hollow cellulose acetate tube and has an inner diameter of about 7.1 millimeters. Accordingly, the thickness of the peripheral wall of the hollow tubular element is about 0.1 millimeters. A ventilation zone is provided at a position along the hollow tubular element.

[0317] The aerosol-generating element is in the form of a rod of aerosol-generating substrate surrounded by a paper wrapper, and comprises at least one of the types of aerosol-generating substrate described above, for example plant cut filler, in particular tobacco cut filler, homogenized tobacco, gel formulations, or homogenized plant material comprising particles of plants other than tobacco.

[0318] An outer tipping wrapper surrounds the hollow tubular element and a portion of the aerosol-generating element, and the hollow tubular element is attached to the aerosol-generating element by the outer tipping wrapper.

[0319] The rod of the aerosol generating substrate has a length of approximately 12 millimeters, and the hollow tubular element has a length of approximately 33 millimeters. Therefore, the total length of the aerosol generating article is approximately 45 millimeters.

[0320] In another preferred embodiment, the aerosol generating article according to the present invention comprises, in a linear continuous arrangement, an upstream element, an aerosol generating element positioned immediately downstream of the upstream element, an aerosol generating element comprising a rod with an aerosol generating substrate, and a hollow tubular element positioned immediately downstream of the aerosol generating element.

[0321] More specifically, the rod of the aerosol generating substrate may be in contact with the upstream element. Furthermore, the hollow tubular element may be in contact with the aerosol generating element.

[0322] The aerosol-generating article has a substantially cylindrical shape and an outer diameter of approximately 7.3 millimeters.

[0323] The hollow tubular element is in the form of a hollow cellulose acetate tube and has an inner diameter of approximately 7.1 millimeters. Therefore, the thickness of the peripheral wall of the hollow tubular element is approximately 0.1 millimeters. The ventilation zone is provided along the hollow tubular element.

[0324] The aerosol generating element is in the form of a rod of an aerosol generating substrate surrounded by a paper wrapper, and comprises at least one of the above types of aerosol generating substrates, such as plant cut filler, in particular tobacco cut filler, homogenized tobacco, gel formulations, or homogenized plant material containing particles of plants other than tobacco.

[0325] The outer chipping wrapper surrounds the hollow tubular element and a portion of the aerosol generating element, and the hollow tubular element is attached to the aerosol generating element.

[0326] The length of the upstream element is 5 millimeters, the length of the rod of the aerosol generating substrate is approximately 12 millimeters, and the length of the hollow tubular element is approximately 28 millimeters. Therefore, the total length of the aerosol generating article is approximately 45 millimeters.

[0327] The present invention is defined in the claims. However, a non-exclusive list of non-limiting embodiments is provided below. One or more features of these embodiments may be combined with one or more features of other embodiments, forms, or aspects described herein.

[0328] Example 1. An aerosol generating article for generating an inhalable aerosol when heated, wherein the aerosol generating article extends from the mouth end to the distal end, An aerosol generating element comprising an aerosol generating substrate, wherein the aerosol generating substrate comprises an aerosol forming body, A downstream section located downstream of an aerosol generating element, comprising a downstream section extending from the downstream end of the aerosol generating element to the mouth end of the aerosol generating article, The downstream section comprises a hollow tubular element, The ratio of the length to the diameter of the aerosol generating element is approximately 0.5 to approximately 3.0. An aerosol generating article in which the aerosol generating substrate contains tobacco cut filler, and the aerosol forming material content in the aerosol generating substrate is at least 8 weight percent. Example 2. The aerosol generating article according to Example 1, wherein the ratio of the length to the diameter of the aerosol generating element is approximately 1.3 to approximately 1.9. Example 3. An aerosol generating article according to Example 1 or 2, wherein the aerosol generating element has a length of approximately 10 mm to approximately 35 mm. Example 4. An aerosol generating article according to any one of Examples 1 to 3, wherein the aerosol generating element has a diameter of approximately 6 mm to approximately 7.5 mm. Example 5. An aerosol generating article according to any one of Examples 1 to 4, wherein the packing density of tobacco cut filler in the aerosol generating element is at least about 100 milligrams / cubic centimeter. Example 6. An aerosol-generating article according to any one of Examples 1 to 5, wherein the tobacco cut filler contains at least about 25 weight percent tobacco leaf lamina. Example 7. An aerosol-generating article according to any one of Examples 1 to 6, wherein the tobacco cut filler contains particles having a cut width of approximately 0.3 mm to approximately 2.0 mm. Example 8. An aerosol generating article according to any one of Examples 1 to 7, wherein the weight of the tobacco cut filler in the aerosol generating element is at least about 100 milligrams. Example 9. An aerosol generating article according to any one of Examples 1 to 8, wherein the aerosol forming material content in the aerosol generating substrate is at least about 10 weight percent. Example 10. An aerosol generating article according to any one of Examples 1 to 9, wherein the downstream section has a ventilation zone positioned along a hollow tubular element. Example 11. The aerosol-generating article according to Example 10, wherein the aerosol-generating article has an air permeability level of at least about 10 percent. Example 12. The aerosol generating article according to Example 10 or 11, wherein the distance between the ventilation zone and the mouth-side end of the aerosol generating article is less than approximately 20 millimeters. Example 13. An aerosol generating article according to any one of Examples 1 to 12, wherein the hollow tubular element has a length of at least about 10 millimeters and the cross-section of the hollow tubular element is substantially constant. Example 14. An aerosol generating article according to any one of Examples 1 to 13, wherein a hollow tubular element extends all the way to the mouth end of the aerosol generating article. Example 15. An aerosol-generating article according to any one of Examples 1 to 13, wherein the downstream section has an RTD of less than approximately 50 mm of H2O.

[0329] The present invention will be further described below with reference to the attached drawings. [Brief explanation of the drawing]

[0330] [Figure 1] Figure 1 shows a schematic side cross-sectional view of an aerosol generating article according to an embodiment of the present invention. [Figure 2] Figure 2 shows a schematic side cross-sectional view of another aerosol generating article according to another embodiment of the present invention. [Figure 3] Figure 3 shows a schematic side cross-sectional view of the deformation of the aerosol-generating article shown in Figure 1. [Figure 4] Figure 4 shows a schematic side cross-sectional view of the deformation of the aerosol-generating article shown in Figure 2. [Modes for carrying out the invention]

[0331] The aerosol generating article 10 shown in Figure 1 comprises a rod 12 of an aerosol generating substrate 12 and a downstream section 14 located downstream of the rod 12 of the aerosol generating substrate. Thus, the aerosol generating article 10 extends from an upstream or distal end 16 substantially coinciding with the upstream end of the rod 12 to a downstream or oral end 18 coinciding with the downstream end of the downstream section 14.

[0332] The aerosol-generating article 10 has a total length of approximately 45 millimeters.

[0333] The rod of the aerosol generating substrate 12 comprises approximately 12 weight percent of an aerosol-forming material, such as glycerin-impregnated tobacco cut filler. The tobacco cut filler contains 90 weight percent of tobacco leaf lamina. The cut width of the tobacco cut filler is approximately 0.7 millimeters. The rod of the aerosol generating substrate 12 comprises approximately 130 milligrams of tobacco cut filler.

[0334] The downstream section 14 comprises a hollow tubular element 20 positioned immediately downstream of the rod 12 of the aerosol generating substrate, the hollow tubular element 20 being longitudinally aligned with the rod 12. In the embodiment shown in Figure 1, the upstream end of the hollow tubular element 20 abuts against the downstream end of the rod 12 of the aerosol generating substrate.

[0335] The hollow tubular element 20 defines the hollow section of the aerosol-generating article 10. The hollow tubular element does not substantially contribute to the overall RTD of the aerosol-generating article. More specifically, the RTD of the downstream section is approximately 0 mmH2O.

[0336] The hollow tubular element 20 is provided in the form of a hollow cylindrical tube made of cellulose acetate or stiff paper, for example, paper having a gram weight of at least about 90 g / sqm. The hollow tubular element 20 defines an internal cavity 22 that extends all the way from the upstream end 24 of the hollow tubular segment to the downstream end 26 of the hollow tubular element 20. The internal cavity 22 is substantially empty and therefore allows for substantially unrestricted airflow along the internal cavity 22. The hollow tubular element 20 does not substantially contribute to the overall RTD of the aerosol-generating article 10.

[0337] The hollow tubular element 20 has a length of approximately 33 mm and an outer diameter of approximately 7.3 mm (D E ), and an inner diameter of approximately 7.1 mm (D I ) has. Therefore, the thickness of the peripheral wall of the hollow tubular element 20 is approximately 0.1 millimeters.

[0338] The aerosol generating article 10 includes a ventilation zone 30 located along a hollow tubular element 20. More specifically, the ventilation zone 30 is located about 18 millimeters from the downstream end 26 of the hollow tubular element 20. In other words, in the embodiment shown in Figure 1, the ventilation zone 30 is effectively located 18 millimeters from the mouth end 18 of the aerosol generating article 10. The ventilation level of the aerosol generating article 10 is about 40 percent.

[0339] In the embodiment shown in Figure 1, the aerosol generating article has no additional components either upstream of the rod of the aerosol generating substrate 12 or downstream of the hollow tubular segment 20.

[0340] The aerosol generating article 100 shown in Figure 2 differs from the aerosol generating article 10 described above only in that an upstream section is provided at a position upstream of the aerosol generating element. Therefore, the aerosol generating article 100 is described only insofar as it differs from the aerosol generating article 10.

[0341] The aerosol generating article 100 includes an upstream section 40 located upstream of the rod 12, at the top of the rod 12 and the downstream section 14 located downstream of the rod 12. Thus, the aerosol generating article 10 extends from a distal end 16 substantially coinciding with the upstream end of the upstream section 40 to a mouth end or downstream end 18 substantially coinciding with the downstream end of the downstream section 14.

[0342] The upstream section 40 comprises an upstream element 42 positioned immediately upstream of the rod 12 of the aerosol generating substrate, the upstream element 42 being longitudinally aligned with the rod 12. In the embodiment shown in Figure 2, the downstream end of the upstream element 42 abuts against the upstream end of the rod 12 of the aerosol generating substrate. The upstream element 42 is provided in the form of a cylindrical plug of cellulose acetate surrounded by a rigid wrapper. The upstream element 42 has a length of approximately 5 millimeters. The RTD of the upstream element 42 is approximately 30 millimeters of H2O.

[0343] Figure 3 shows an aerosol generating article 200, which is a variation of the aerosol generating article 10 described above. The aerosol generating article 200 is generally identical to the aerosol generating article 10 of the embodiment in Figure 1, except that the aerosol generating article 200 of the variation of the first embodiment does not include the cylindrical hollow tubular element 22 as described above. Instead, the aerosol generating article 200 of the variation of the first embodiment includes a modified tubular element 220 located immediately downstream of the aerosol generating element 12.

[0344] The modified tubular element 220 comprises a tubular body 222 that defines a cavity 224 extending from a first end of the tubular body 222 to a second end of the tubular body 222. The modified tubular element 220 also comprises a folded end portion forming a first end wall 226 at the first end of the tubular body 222. The first end wall 226 defines an opening 228 that allows airflow between the cavity 224 and the exterior of the modified tubular element 220. Specifically, the embodiment of Figure 3 is configured such that aerosol can flow from the aerosol-generating element 12 through the opening 228 and into the cavity 224.

[0345] Substantially similar to the cavity 22 of the first embodiment shown in Figure 1, the cavity 224 of the tubular body 222 is substantially empty, thus allowing substantially unrestricted airflow along the cavity 222. As a result, the RTD of the modified tubular element 220 can be localized at a specific longitudinal position of the modified tubular element 220, namely at the first end wall 226, and can be controlled through the selected configuration of the first end wall 226 and its corresponding opening 228.

[0346] In the embodiment of Figure 3, the modified tubular element 220 has a length of approximately 33 millimeters, an outer diameter of approximately 7.3 millimeters (D E ), and an inner diameter of approximately 7.1 millimeters (D FTS ). Accordingly, the thickness of the peripheral wall of the tubular body 222 is approximately 0.1 millimeter.

[0347] Figure 4 shows an aerosol generating article 300, which is a variation of the aerosol generating article 100 described above. The aerosol generating article 300 is generally identical to the aerosol generating article 100 of the embodiment in Figure 2, except that the aerosol generating article 300 of the second embodiment variant does not include an upstream element 42, which is provided in the form of a cylindrical plug of cellulose acetate surrounded by a rigid wrapper. Instead, the aerosol generating article 300 of the variation of the second embodiment includes a second tubular element 44 located immediately upstream of the aerosol generating element 12. Thus, in this variation of the second embodiment, a hollow tubular element 20 located immediately downstream of the aerosol generating element 12 may be referred to as the first tubular element 20.

[0348] The second tubular element 44 comprises a tubular body 46 defining a cavity 48 extending from a first end of the tubular body 46 to a second end of the tubular body 46. The second tubular element 44 also comprises a folded end portion that forms a first end wall 50 at the first end of the tubular body 46. The first end wall 50 defines an opening 52 that allows airflow between the cavity 48 and the outside of the second tubular element 44. Specifically, the embodiment in Figure 4 is configured such that air can flow from the cavity 48 through the opening 52 into the aerosol generating element 12.

[0349] Furthermore, the second tubular element 44 is provided with a second end wall 54 at the second end of its tubular body 46. This second end wall 54 is formed by folding the end portion of the second tubular element 44 at the second end of the tubular body 46. The second end wall 54 defines an opening 56 that allows airflow between the cavity 48 and the outside of the second tubular element 44. In the case of the second end wall 54, the opening 56 is configured so that air can flow through the opening 56 from the outside of the aerosol generating article 300 into the cavity 48. Thus, the opening 56 provides a conduit through which air can be drawn into the aerosol generating article 300 and through the aerosol generating element 12.

[0350] In the deformation shown in Figure 4, the downstream end of the second tubular element 44 abuts against the upstream end of the aerosol generating substrate 12. The second tubular element 44 has a length of approximately 5 millimeters.

Claims

1. An aerosol generating article for generating an inhalable aerosol when heated, wherein the aerosol generating article extends from the mouth end to the distal end, An aerosol generating element having a diameter of 6 mm to 7.5 mm and comprising an aerosol generating substrate, wherein the aerosol generating substrate comprises an aerosol forming body, A downstream section located downstream of the aerosol generating element, comprising a downstream section extending from the downstream end of the aerosol generating element to the mouth end of the aerosol generating article, The downstream section comprises a hollow tubular element and a ventilation zone positioned along the hollow tubular element, and the aerosol-generating article has a ventilation level of at least 10 percent. The ratio of the length to the diameter of the aerosol generating element is 0.5 to 2.

75. The aerosol generating substrate comprises tobacco cut filler, and the aerosol forming material content in the aerosol generating substrate is at least 8% by weight. The aerosol generating article further comprises an upstream section located upstream of the rod of the aerosol generating substrate, The hollow annular element extends all the way from the upstream end of the downstream section to the mouth end of the aerosol generating article. Aerosol-generating items.

2. The aerosol generating article according to claim 1, wherein the ratio of the length to the diameter of the aerosol generating element is 1.3 to 1.

9.

3. The aerosol generating article according to claim 1 or 2, wherein the aerosol generating element has a length of 10 mm to 35 mm.

4. The aerosol generating article according to any one of claims 1 to 3, wherein the filling density of the tobacco cut filler in the aerosol generating element is at least 100 milligrams / cubic centimeter.

5. The aerosol generating article according to any one of claims 1 to 4, wherein the tobacco cut filler comprises at least 25 weight percent of tobacco leaf lamina.

6. The aerosol generating article according to any one of claims 1 to 5, wherein the tobacco cut filler comprises particles having a cut width of 0.3 mm to 2.0 mm.

7. The aerosol generating article according to any one of claims 1 to 6, wherein the weight of the tobacco cut filler in the aerosol generating element is at least 100 milligrams.

8. The aerosol generating article according to any one of claims 1 to 7, wherein the aerosol forming material content in the aerosol generating substrate is at least 10 percent by weight.

9. The aerosol generating article according to any one of claims 1 to 8, wherein the distance between the ventilation zone and the mouth end of the aerosol generating article is less than 20 millimeters.

10. The aerosol generating article according to any one of claims 1 to 9, wherein the hollow tubular element has a length of at least 10 millimeters and the cross-section of the hollow tubular element is substantially constant.

11. The aforementioned downstream section is 50 mm H 2 An aerosol-generating article according to any one of claims 1 to 10, having an RTD of less than 0.

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