An aerosol generating article having two aerosol generating segments

Abstract

An aerosol-generating article (10, 110, 210) comprising an aerosol-generating rod (12, 112, 212) for generating an inhalable aerosol upon heating, the aerosol-generating rod (12, 112, 212) comprising a first aerosol-generating segment (24, 124, 224) comprising a first aerosol-generating substrate, and a second aerosol-generating segment (26, 126, 226) located upstream of the first aerosol-generating segment (24, 124, 224) and comprising a second aerosol-generating substrate, wherein a total combined length of the first aerosol-generating segment (24, 124, 224) and the second aerosol-generating segment (26, 126, 226) is at least 20 millimeters, a ratio of the total combined length of the first aerosol-generating segment (24, 124, 224) and the second aerosol-generating segment (26, 126, 226) to an overall length of the aerosol-generating article (10, 110, 210) is 0.6 or less, and the aerosol-generating article has a ventilation level of at least 40 percent, the aerosol-generating article (10, 110, 210).

Description

Technical Field

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

Background Art

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

[0003] Numerous prior art documents disclose aerosol generating devices for consuming aerosol generating articles. Such devices include, for example, electrically heated aerosol generating devices in which an aerosol is generated by heat transfer from one or more electrical heater elements of the aerosol generating device to the aerosol generating substrate of the heated aerosol generating article. For example, an electrically heated aerosol generating device has been proposed that includes an internal heater blade adapted to be inserted into the aerosol generating substrate. The use of aerosol generating articles in combination with external heating systems is also known. For example, WO2020 / 115151 describes the provision of one or more heating elements arranged around the periphery of an aerosol generating article when the aerosol generating article is received within a cavity of the aerosol generating device. Alternatively, an inductively heatable aerosol generating article comprising an aerosol generating substrate and a susceptor disposed within the aerosol generating substrate has been proposed by WO2015 / 176898.

Summary of the Invention

Problems to be Solved by the Invention

[0004] Known heated tobacco products typically comprise a single tobacco-containing substrate. Variations in the internal structure of the tobacco-containing substrate can affect the draw resistance of the tobacco-containing substrate and thus the draw resistance (RTD) of the tobacco product. Such variations can be the result of, for example, manufacturing defects or the presence of contaminants. Accordingly, tobacco products can suffer from one or more drawbacks such as a mismatch in draw resistance between one tobacco product and another. Such mismatches can be particularly pronounced in tobacco products having a single relatively long tobacco-containing substrate.

[0005] The draw resistance of a tobacco product can affect the composition and temperature of the aerosol delivered to the user. Accordingly, a mismatch in draw resistance of a tobacco product can result in variations in the composition and temperature of the aerosol generated by the tobacco product. For example, during the manufacture of the tobacco-containing substrate, gravitational settling of the substrate material can result in the formation of some relatively large channels through the tobacco-containing substrate. Upon heating, the tobacco-containing substrate generates an aerosol that can preferentially flow through such channels. The presence of relatively large channels through the tobacco-containing substrate can thereby affect the composition of the aerosol delivered to the user. The presence of relatively large channels through the tobacco-containing substrate can thereby lead to the aerosol reaching the user at an uncomfortable temperature.

[0006] The tobacco-containing substrate is typically heated to a significantly lower temperature compared to the temperature reached by the burning tip of a conventional cigarette. This can affect nicotine release from the tobacco-containing substrate and nicotine delivery to the consumer. At the same time, when attempting to increase the heating temperature to promote nicotine delivery, typically, the generated aerosol needs to be cooled over a wider area and more rapidly before reaching the consumer. Some known heated tobacco products include a ventilation zone for cooling the aerosol generated before reaching the consumer. Increasing the ventilation level may increase the cooling of the generated aerosol. However, increasing the ventilation level can amplify the effects that the draw resistance of the tobacco product may have on the composition and temperature of the aerosol delivered to the user.

[0007] Therefore, it would be desirable to provide an aerosol-generating article with improved quality and consistency of the aerosol delivered to the user compared to known heated tobacco products.

Brief Description of the Drawings

[0008]

Figure 1

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Figure 5

Modes for Carrying Out the Invention

[0009] The present disclosure relates to an aerosol generating article comprising an aerosol generating rod for generating an inhalable aerosol upon heating. The aerosol generating rod may comprise a first aerosol generating segment. The first aerosol generating segment may comprise a first aerosol generating substrate. The aerosol generating rod may comprise a second aerosol generating segment. The second aerosol generating segment may be located upstream of the first aerosol generating segment. The second aerosol generating segment may comprise a second aerosol generating substrate. The total combined length of the first aerosol generating segment and the second aerosol generating segment may be at least 20 millimeters. The aerosol generating article may have a ventilation level of at least 40 percent.

[0010] According to a first aspect of the present invention, there is provided an aerosol generating article comprising an aerosol generating rod for generating an inhalable aerosol upon heating, the aerosol generating rod comprising a first aerosol generating segment comprising a first aerosol generating substrate and a second aerosol generating segment located upstream of the first aerosol generating segment and comprising a second aerosol generating substrate, the total combined length of the first aerosol generating segment and the second aerosol generating segment being at least 20 millimeters, and the aerosol generating article having a ventilation level of at least 40 percent.

[0011] In a preferred embodiment, there is provided an aerosol-generating article comprising an aerosol-generating rod for generating an inhalable aerosol upon heating, the aerosol-generating rod comprising a first aerosol-generating segment comprising a first aerosol-generating substrate and a second aerosol-generating segment located upstream of the first aerosol-generating segment and comprising a second aerosol-generating substrate, the combined length of the first aerosol-generating segment and the second aerosol-generating segment being at least 20 millimeters, the length of the first aerosol-generating segment being substantially equal to the length of the second aerosol-generating segment, and the aerosol-generating article having a ventilation level of at least 40 percent.

[0012] In a preferred embodiment, there is provided an aerosol-generating article comprising an aerosol-generating rod for generating an inhalable aerosol upon heating, the aerosol-generating rod comprising a first aerosol-generating segment comprising a first aerosol-generating substrate and a second aerosol-generating segment located upstream of the first aerosol-generating segment and comprising a second aerosol-generating substrate, the combined length of the first aerosol-generating segment and the second aerosol-generating segment being at least 20 millimeters, the composition of the first aerosol-generating segment being substantially the same as the composition of the second aerosol-generating segment, and the aerosol-generating article having a ventilation level of at least 40 percent.

[0013] In a preferred embodiment, there is provided an aerosol-generating article comprising an aerosol-generating rod for generating an inhalable aerosol upon heating, the aerosol-generating rod comprising a first aerosol-generating segment comprising a first aerosol-generating substrate and a second aerosol-generating segment located upstream of the first aerosol-generating segment and comprising a second aerosol-generating substrate, the total combined length of the first aerosol-generating segment and the second aerosol-generating segment being at least 20 millimeters, the length of the first aerosol-generating segment being approximately equal to the length of the second aerosol-generating segment, the composition of the first aerosol-generating segment being substantially the same as the composition of the second aerosol-generating segment, and the aerosol-generating article having a ventilation level of at least 40 percent.

[0014] The present disclosure also relates to an aerosol-generating system. The aerosol-generating system may comprise an aerosol-generating article as described above. The aerosol-generating system may comprise an aerosol-generating device. The aerosol-generating device may comprise a heating chamber for receiving at least a portion of the aerosol-generating article. The aerosol-generating device may comprise a heater. The heater may be for heating the aerosol-generating rod of the aerosol-generating article when the aerosol-generating article is received within the heating chamber.

[0015] According to a second aspect of the present invention, there is provided an aerosol-generating system comprising an aerosol-generating article according to a first aspect of the present invention and an aerosol-generating device, the aerosol-generating device comprising a heating chamber for receiving at least a portion of the aerosol-generating article and a heater for heating the aerosol-generating rod of the aerosol-generating article when the aerosol-generating article is received within the heating chamber.

[0016] As used herein in connection with the present invention, the term "aerosol-generating article" is used to describe an article comprising an aerosol-generating substrate that generates a heated inhalable aerosol for delivery to a user.

[0017] As used herein in the context of the present invention, the term "aerosol-generating substrate" is used to describe a substrate that includes an aerosol-generating material having the ability to release a volatile compound that can generate an aerosol upon heating.

[0018] As used herein in the context of the present invention, the term "aerosol" is used to describe a dispersion of solid particles, or droplets, or a combination of solid particles and droplets in a gas. The aerosol may be visible or invisible. The aerosol may include not only the vapor of a substance that is normally liquid or solid at room temperature, but also solid particles or liquid droplets, or a combination of solid particles and liquid droplets.

[0019] As used herein in the context of the present invention, the term "aerosol-generating device" is used to describe a device that interacts with an aerosol-generating substrate of an aerosol-generating article to generate an aerosol.

[0020] As used herein in the context of the present invention, the term "rod" is used to denote a generally cylindrical element having a substantially circular, oval or elliptical cross-section.

[0021] An aerosol-generating article according to the present invention has a proximal end through which, in use, an aerosol exits the aerosol-generating article for delivery to a user. The proximal end of the aerosol-generating article may also be referred to as the downstream end or the mouth-side end of the aerosol-generating article. In use, a user directly or indirectly inhales the proximal end of the aerosol-generating article to inhale the aerosol generated by the aerosol-generating article.

[0022] An aerosol-generating article according to the present invention has a distal end. The distal end is on the opposite side of the proximal end. The distal end of the aerosol-generating article may also be referred to as the upstream end of the aerosol-generating article.

[0023] The components of the aerosol-generating article according to the present invention can be described as being upstream or downstream of each other based on their relative positions between the proximal end and the distal end of the aerosol-generating article.

[0024] As used herein in the context of the present invention, the term "longitudinal direction" is used to describe the direction between the upstream end and the downstream end of the aerosol-generating article. During use, air is drawn through the aerosol-generating article in the longitudinal direction.

[0025] As used herein in the context of the present invention, the term "length" is used to describe the maximum dimension of the aerosol-generating article or a component of the aerosol-generating article in the longitudinal direction.

[0026] As used herein in the context of the present invention, the term "transverse direction" is used to describe a direction perpendicular to the longitudinal direction. Unless otherwise specified, the "cross-section" of the aerosol-generating article or a component of the aerosol-generating article refers to the cross-sectional plane.

[0027] As used in connection with the present invention, the term "ventilation level" is used to indicate the volume ratio of the airflow (ventilation airflow) flowing into the aerosol-generating article through the ventilation zone to the total of the aerosol airflow and the ventilation airflow. The greater the ventilation level, the higher the dilution of the aerosol stream delivered to the consumer.

[0028] An aerosol-generating article according to a first aspect of the present invention comprises an aerosol-generating rod for generating an inhalable aerosol upon heating, the aerosol-generating rod comprising a first aerosol-generating segment comprising a first aerosol-generating substrate and a second aerosol-generating segment located upstream of the first aerosol-generating segment and comprising a second aerosol-generating substrate, the combined length of the first aerosol-generating segment and the second aerosol-generating segment being at least about 20 millimeters, and the aerosol-generating article having a ventilation level of at least about 40 percent. By including these features in an aerosol-generating article according to a first aspect of the present invention, advantageously, the quality and consistency of the aerosol generated by one aerosol-generating article relative to the aerosol generated by another aerosol-generating article may be improved.

[0029] An aerosol-generating rod comprising a first aerosol-generating segment and a second aerosol-generating segment can minimize or offset the effect of variations in the internal structure of one of the aerosol-generating segments on the draw resistance that can affect the entire aerosol-generating rod and thus the aerosol-generating article. As described above, the impact of variations in the internal structure of the aerosol-generating segment on the overall draw resistance of the aerosol-generating article can be particularly pronounced in an aerosol-generating article comprising a single relatively long aerosol-generating segment (e.g., at least 20 millimeters). Thereby, an aerosol-generating rod comprising a first aerosol-generating segment and a second aerosol-generating segment can improve the consistency of the draw resistance of the aerosol-generating article. Thereby, the quality and consistency of the aerosol delivered to the user by the aerosol-generating article can be improved. This can be particularly advantageous when the aerosol-generating article has a relatively high ventilation level (e.g., at least 40 percent).

[0030] The aerosol-generating rod comprises a first aerosol-generating segment and a second aerosol-generating segment. The first aerosol-generating segment is physically different from the second aerosol-generating segment.

[0031] Preferably, the second aerosol generation segment is at the upstream end of the aerosol generation rod. Preferably, the first aerosol generation segment is at the downstream end of the aerosol generation rod.

[0032] Preferably, the first aerosol generation segment and the second aerosol generation segment are aligned in an end-to-end relationship. That is, preferably, the downstream end of the second aerosol generation segment abuts against the upstream end of the first aerosol generation segment. Preferably, substantially the entire surface of the downstream end of the second aerosol generation segment abuts against substantially the entire surface of the upstream end of the first aerosol generation segment.

[0033] Preferably, the aerosol generation rod consists of the first aerosol generation segment and the second aerosol generation segment.

[0034] The total combined length of the first aerosol generation segment and the second aerosol generation segment is at least 20 millimeters. Preferably, the total combined length of the first aerosol generation segment and the second aerosol generation segment is at least 25 millimeters. More preferably, the total combined length of the first aerosol generation segment and the second aerosol generation segment is at least 30 millimeters.

[0035] The total combined length of the first aerosol generation segment and the second aerosol generation segment is preferably less than 50 millimeters. Preferably, the total combined length of the first aerosol generation segment and the second aerosol generation segment is less than 45 millimeters. More preferably, the total combined length of the first aerosol generation segment and the second aerosol generation segment is less than 40 millimeters.

[0036] For example, the total combined length of the first aerosol generation segment and the second aerosol generation segment is preferably 20 millimeters to 50 millimeters, or 20 millimeters to 45 millimeters, or 20 millimeters to 40 millimeters, or 25 millimeters to 50 millimeters, or 25 millimeters to 45 millimeters, or 25 millimeters to 40 millimeters, or 30 millimeters to 50 millimeters, or 30 millimeters to 45 millimeters, or 30 millimeters to 40 millimeters.

[0037] In an aerosol generation rod having a single aerosol generation segment, increasing the length of the single aerosol generation segment may increase the impact of fluctuations in the internal structure of the single aerosol generation segment on the single aerosol generation segment and thus on the aerosol generation rod. As a result, the level of inconsistency between aerosol generation articles comprising an aerosol generation rod having a single aerosol generation segment may increase. Accordingly, the aerosol generation article according to the present invention comprising an aerosol generation rod having a first aerosol generation segment and a second aerosol generation segment may be particularly effective in minimizing or canceling out the effects that fluctuations in the internal structure of one of the aerosol generation segments may have on an aerosol generation rod having a relatively high total combined length of the first aerosol generation segment and the second aerosol generation segment.

[0038] Preferably, the length of the second aerosol generation segment is approximately equal to the length of the first aerosol generation segment. This can help minimize or cancel out the impact of fluctuations in the internal structure of the other aerosol generation segment on the overall aerosol generation rod. The fact that the lengths of the first aerosol generation segment and the second aerosol generation segment are approximately equal can also simplify the manufacture of the aerosol generation rod.

[0039] Preferably, the length of the second aerosol generation segment is within 2 millimeters of the length of the first aerosol generation segment, or within 1 millimeter of the length of the first aerosol generation segment.

[0040] Preferably, the length of the second aerosol generation segment is within 10 percent of the length of the first aerosol generation segment, or within 5 percent of the length of the first aerosol generation segment, or within 3 percent of the length of the first aerosol generation segment.

[0041] The relative lengths of the first aerosol generation segment and the second aerosol generation segment can be selected to optimize aerosol delivery.

[0042] In some embodiments, the length of the second aerosol generation segment may be greater than the length of the first aerosol generation segment. That is, the second aerosol generation segment may be longer than the first aerosol generation segment.

[0043] In some embodiments, the length of the second aerosol generation segment may be at least 3 millimeters greater than the length of the first aerosol generation segment. For example, the second aerosol generation segment may be at least 4 millimeters greater, at least 5 millimeters greater, or at least 6 millimeters greater than the length of the first aerosol generation segment.

[0044] In some embodiments, the length of the second aerosol generation segment may be up to 12 millimeters greater than the length of the first aerosol generation segment. For example, the second aerosol generation segment may be up to 10 millimeters, up to 9 millimeters, or up to 8 millimeters greater than the length of the first aerosol generation segment.

[0045] In some embodiments, the length of the second aerosol generation segment may be about 7 millimeters greater than the length of the first aerosol generation segment.

[0046] In some embodiments, the ratio of the length of the first aerosol generation segment to the length of the second aerosol generation segment may be 1 or less. For example, the ratio of the length of the first aerosol generation segment to the length of the second aerosol generation segment may be 0.8 or less, 0.6 or less, or 0.5 or less.

[0047] In some embodiments, the ratio of the length of the first aerosol generation segment to the length of the second aerosol generation segment may be at least 0.1. For example, the ratio of the length of the first aerosol generation segment to the length of the second aerosol generation segment may be at least 0.2, at least 0.3, or at least 0.4.

[0048] In some embodiments, the ratio of the length of the first aerosol generation segment to the length of the second aerosol generation segment may be 0.1 - 1, 0.2 - 0.8, 0.3 - 0.6, or 0.4 - 0.5. For example, the ratio of the length of the first aerosol generation segment to the length of the second aerosol generation segment may be about 0.4.

[0049] In some embodiments, the length of the first aerosol generation segment may be greater than the length of the second aerosol generation segment. That is, the first aerosol generation segment may be longer than the second aerosol generation segment.

[0050] In some embodiments, the length of the first aerosol generation segment may be at least 3 millimeters greater than the length of the second aerosol generation segment. For example, the first aerosol generation segment may be at least 4 millimeters greater, at least 5 millimeters greater, or at least 6 millimeters greater than the length of the second aerosol generation segment.

[0051] In some embodiments, the length of the first aerosol generation segment may not be greater than 12 millimeters more than the length of the second aerosol generation segment. For example, the first aerosol generation segment may be not greater than 10 millimeters, not greater than 9 millimeters, or not greater than 8 millimeters more than the length of the second aerosol generation segment.

[0052] In some embodiments, the length of the first aerosol generation segment may be about 7 millimeters greater than the length of the second aerosol generation segment.

[0053] In some embodiments, the ratio of the length of the second aerosol generation segment to the length of the first aerosol generation segment may be 1 or less. For example, the ratio of the length of the second aerosol generation segment to the length of the first aerosol generation segment may be 0.8 or less, 0.6 or less, or 0.5 or less.

[0054] In some embodiments, the ratio of the length of the second aerosol generation segment to the length of the first aerosol generation segment may be at least 0.1. For example, the ratio of the length of the second aerosol generation segment to the length of the first aerosol generation segment may be at least 0.2, at least 0.3, or at least 0.4.

[0055] In some embodiments, the ratio of the length of the second aerosol generation segment to the length of the first aerosol generation segment may be 0.1 - 1, 0.2 - 0.8, 0.3 - 0.6, or 0.4 - 0.5. For example, the ratio of the length of the second aerosol generation segment to the length of the first aerosol generation segment may be about 0.4.

[0056] Preferably, the first aerosol generation segment has a length of at least 10 millimeters. More preferably, the length of the first aerosol generation segment is at least 12.5 millimeters. Even more preferably, the length of the first aerosol generation segment is at least 15 millimeters.

[0057] Preferably, the length of the first aerosol generation segment is 25 millimeters or less. Preferably, the length of the first aerosol generation segment is 22.5 millimeters or less. More preferably, the length of the first aerosol generation segment is less than 20 millimeters.

[0058] For example, the length of the first aerosol generation segment is preferably 10 millimeters to 25 millimeters, or 10 millimeters to 22.5 millimeters, or 10 millimeters to 20 millimeters, or 12.5 millimeters to 25 millimeters, or 12.5 millimeters to 22.5 millimeters, or 12.5 millimeters to 20 millimeters, or 15 millimeters to 25 millimeters, or 15 millimeters to 22.5 millimeters, or 15 millimeters to 20 millimeters.

[0059] Preferably, the second aerosol generation segment has a length of at least 10 millimeters. More preferably, the length of the second aerosol generation segment is at least 12.5 millimeters. Even more preferably, the length of the second aerosol generation segment is at least 15 millimeters.

[0060] Preferably, the length of the second aerosol generation segment is less than 25 millimeters. Preferably, the length of the second aerosol generation segment is less than 22.5 millimeters. More preferably, the length of the second aerosol generation segment is less than 20 millimeters.

[0061] For example, the length of the second aerosol generation segment is preferably 10 millimeters to 25 millimeters, or 10 millimeters to 22.5 millimeters, or 10 millimeters to 20 millimeters, or 12.5 millimeters to 25 millimeters, or 12.5 millimeters to 22.5 millimeters, or 12.5 millimeters to 20 millimeters, or 15 millimeters to 25 millimeters, or 15 millimeters to 22.5 millimeters, or 15 millimeters to 20 millimeters.

[0062] When the aerosol generation rod consists of a first aerosol generation segment and a second aerosol generation segment, and the first aerosol generation segment and the second aerosol generation segment are aligned in a relationship where adjacent ends are in contact, the total combined length of the first aerosol generation segment and the second aerosol generation segment is the same as the length of the aerosol generation rod.

[0063] The aerosol generation rod preferably has a length of at least 20 millimeters. Preferably, the aerosol generation rod has a length of at least 25 millimeters. More preferably, the aerosol generation rod has a length of at least 30 millimeters.

[0064] The aerosol generation rod preferably has a length of 50 millimeters or less. Preferably, the aerosol generation rod has a length of 45 millimeters or less. More preferably, the aerosol generation rod has a length of 40 millimeters or less.

[0065] For example, the aerosol generation rod preferably has a length of 20 millimeters to 50 millimeters, or 20 millimeters to 45 millimeters, or 20 millimeters to 40 millimeters, or 25 millimeters to 50 millimeters, or 25 millimeters to 45 millimeters, or 25 millimeters to 40 millimeters, or 30 millimeters to 50 millimeters, or 30 millimeters to 45 millimeters, or 30 millimeters to 40 millimeters.

[0066] The ratio of the total combined length of the first aerosol generating segment and the second aerosol generating segment to the total length of the aerosol generating article is preferably at least 0.20. Preferably, the ratio of the total combined length of the first aerosol generating segment and the second aerosol generating segment to the total length of the aerosol generating article is at least 0.25. More preferably, the ratio of the total combined length of the first aerosol generating segment and the second aerosol generating segment to the total length of the aerosol generating article is at least 0.30.

[0067] The ratio of the total combined length of the first aerosol generating segment and the second aerosol generating segment to the total length of the aerosol generating article is preferably 0.60 or less. Preferably, the ratio of the total combined length of the first aerosol generating segment and the second aerosol generating segment to the total length of the aerosol generating article is 0.55 or less. More preferably, the ratio of the total combined length of the first aerosol generating segment and the second aerosol generating segment to the total length of the aerosol generating article is 0.50 or less.

[0068] In some embodiments, the ratio of the total combined length of the first aerosol generating segment and the second aerosol generating segment to the total length of the aerosol generating article is 0.20 to 0.60, preferably 0.20 to 0.55, more preferably 0.20 to 0.50. In other embodiments, the ratio of the length of the aerosol generating rod to the total length of the aerosol generating article is 0.25 to 0.60, preferably 0.25 to 0.55, more preferably 0.25 to 0.50. In further embodiments, the ratio of the length of the aerosol generating rod to the total length of the aerosol generating article is 0.30 to 0.60, preferably 0.30 to 0.55, more preferably 0.30 to 0.50.

[0069] The ratio of the length of the first aerosol generation segment to the total length of the aerosol generating article is preferably at least 0.10. Preferably, the ratio of the length of the first aerosol generation segment to the total length of the aerosol generating article is at least 0.12. More preferably, the ratio of the length of the first aerosol generation segment to the total length of the aerosol generating article is at least 0.15.

[0070] The ratio of the length of the first aerosol generation segment to the total length of the aerosol generating article is preferably 0.30 or less. Preferably, the ratio of the length of the first aerosol generation segment to the total length of the aerosol generating article is 0.27 or less. More preferably, the ratio of the length of the first aerosol generation segment to the total length of the aerosol generating article is 0.25 or less.

[0071] In some embodiments, the ratio of the length of the first aerosol generation segment to the total length of the aerosol generating article is 0.10 to 0.30, preferably 0.10 to 0.27, more preferably 0.10 to 0.25. In other embodiments, the ratio of the length of the first aerosol generation segment to the total length of the aerosol generating article is 0.12 to 0.30, preferably 0.12 to 0.27, more preferably 0.12 to 0.25. In further embodiments, the ratio of the length of the first aerosol generation segment to the total length of the aerosol generating article is 0.15 to 0.30, preferably 0.15 to 0.27, more preferably 0.30 to 0.25.

[0072] The ratio of the length of the second aerosol generation segment to the total length of the aerosol generating article is preferably at least 0.10. Preferably, the ratio of the length of the second aerosol generation segment to the total length of the aerosol generating article is at least 0.12. More preferably, the ratio of the length of the second aerosol generation segment to the total length of the aerosol generating article is at least 0.15.

[0073] The ratio of the length of the second aerosol generation segment to the total length of the aerosol generating article is preferably 0.30 or less. Preferably, the ratio of the length of the second aerosol generation segment to the total length of the aerosol generating article is 0.27 or less. More preferably, the ratio of the length of the second aerosol generation segment to the total length of the aerosol generating article is 0.25 or less.

[0074] In some embodiments, the ratio of the length of the second aerosol generation segment to the total length of the aerosol generating article is 0.10 to 0.30, preferably 0.10 to 0.27, more preferably 0.10 to 0.25. In other embodiments, the ratio of the length of the second aerosol generation segment to the total length of the aerosol generating article is 0.12 to 0.30, preferably 0.12 to 0.27, more preferably 0.12 to 0.25. In further embodiments, the ratio of the length of the second aerosol generation segment to the total length of the aerosol generating article is 0.15 to 0.30, preferably 0.15 to 0.27, more preferably 0.30 to 0.25.

[0075] The ratio of the length of the aerosol generation rod to the total length of the aerosol generating article is preferably at least 0.20. Preferably, the ratio of the length of the aerosol generation rod to the total length of the aerosol generating article is at least 0.25. More preferably, the ratio of the length of the aerosol generation rod to the total length of the aerosol generating article is at least 0.30.

[0076] The ratio of the length of the aerosol generation rod to the total length of the aerosol generating article is preferably 0.60 or less. Preferably, the ratio of the length of the aerosol generation rod to the total length of the aerosol generating article is 0.55 or less. More preferably, the ratio of the length of the aerosol generation rod to the total length of the aerosol generating article is 0.50 or less.

[0077] In some embodiments, the ratio of the length of the aerosol generating rod to the total length of the aerosol generating article is from 0.20 to 0.60, preferably from 0.20 to 0.55, more preferably from 0.20 to 0.50. In other embodiments, the ratio of the length of the aerosol generating rod to the total length of the aerosol generating article is from 0.25 to 0.60, preferably from 0.25 to 0.55, more preferably from 0.25 to 0.50. In further embodiments, the ratio of the length of the aerosol generating rod to the total length of the aerosol generating article is from 0.30 to 0.60, preferably from 0.30 to 0.55, more preferably from 0.30 to 0.50.

[0078] The aerosol generating rod preferably has an outer diameter substantially equal to the outer diameter of the aerosol generating article.

[0079] As used herein, the term "outer diameter" of a component of an aerosol generating article can be calculated as the average of a plurality of measurements of the diameter of the component of the aerosol generating article taken at different locations along the length of the component of the aerosol generating article.

[0080] Preferably, the aerosol generating rod has an outer diameter of at least about 5 millimeters. More preferably, the aerosol generating rod has an outer diameter of at least 5.25 millimeters. Even more preferably, the aerosol generating rod has an outer diameter of at least 5.5 millimeters.

[0081] The aerosol generating rod preferably has an outer diameter of 8 millimeters or less. More preferably, the aerosol generating rod has an outer diameter of 7.5 millimeters or less. Even more preferably, the aerosol generating rod has an outer diameter of 7 millimeters or less.

[0082] Generally, it has been observed that the smaller the diameter of the aerosol generating rod, the lower the temperature required to raise the core temperature of the aerosol generating rod so that a sufficient amount of vaporizable species is released from the aerosol generating substrate to form the desired amount of aerosol. At the same time, without wishing to be bound by theory, it is understood that the smaller the diameter of the aerosol generating rod, the more readily the heat supplied to the aerosol generating article penetrates through the total volume of the aerosol generating substrate. Nevertheless, if the diameter of the aerosol generating rod is too small, as the amount of available aerosol generating substrate decreases, one or both of the volume-to-surface ratios of the aerosol generating substrate become less favorable.

[0083] The diameter of the aerosol generating rod falling within the ranges described herein is particularly advantageous from the perspective of the balance between energy consumption and aerosol delivery. This advantage is particularly felt when using an aerosol generating article comprising an aerosol generating rod having the diameter described herein in combination with an external heater disposed around the outer periphery of the aerosol generating article. Under such operating conditions, it has been observed that generally less thermal energy is required to achieve a sufficiently high temperature in the core of the article, and thus in the core of the aerosol generating rod. Therefore, when operating at a lower temperature, the desired target temperature in the core of the aerosol generating substrate may be achieved within a desirably reduced time frame and with less energy consumption.

[0084] The use of an aerosol generating rod having a smaller diameter also advantageously reduces the total weight of tobacco material required for the aerosol generating article while still being able to produce the desired level of aerosol in some cases. Accordingly, the level of tobacco waste can be reduced.

[0085] Preferably, the aerosol generating rod has a substantially circular cross-section. Preferably, the aerosol generating rod has a substantially uniform cross-section along the entire length of the aerosol generating rod.

[0086] Preferably, one or both of the first aerosol generation segment and the second aerosol generation segment have a substantially circular cross-section. For example, one or both of the first aerosol generation segment and the second aerosol generation segment are preferably substantially cylindrical.

[0087] Preferably, the outer diameter of the first aerosol generation segment is approximately equal to the outer diameter of the second aerosol generation segment.

[0088] Preferably, the outer diameter of one or both of the first aerosol generation segments is approximately equal to the outer diameter of the aerosol generation rod.

[0089] Preferably, the outer diameter of one or both of the first aerosol generation segments is approximately equal to the outer diameter of the aerosol generation article.

[0090] Preferably, the outer diameter of the first aerosol generation segment is 5 millimeters to 8 millimeters, more preferably 5.25 millimeters to 7.5 millimeters, and even more preferably 5.5 millimeters to 7 millimeters.

[0091] Preferably, the outer diameter of the second aerosol generation segment is 5 millimeters to 8 millimeters, more preferably 5.25 millimeters to 7.5 millimeters, and even more preferably 5.5 millimeters to 7 millimeters.

[0092] The average cross-sectional area of the first aerosol generation segment is preferably at least 50 percent, more preferably at least 80 percent, and even more preferably at least 90 percent of the average cross-sectional area of the aerosol generation article.

[0093] The average cross-sectional area of the first aerosol generation segment at its upstream end is preferably at least 50 percent of the average cross-sectional area of the aerosol generating article, more preferably at least 80 percent of the average cross-sectional area of the aerosol generating article, and still more preferably at least 90 percent of the average cross-sectional area of the aerosol generating article.

[0094] The average cross-sectional area of the second aerosol generation segment is preferably at least 50 percent of the average cross-sectional area of the aerosol generating article, more preferably at least 80 percent of the average cross-sectional area of the aerosol generating article, and still more preferably at least 90 percent of the average cross-sectional area of the aerosol generating article.

[0095] The cross-sectional area of the second aerosol generation segment at its downstream end is preferably at least 50 percent of the average cross-sectional area of the aerosol generating article, more preferably at least 80 percent of the average cross-sectional area of the aerosol generating article, and still more preferably at least 90 percent of the average cross-sectional area of the aerosol generating article.

[0096] Preferably, the shape and size of the first aerosol generation segment are the same as the shape and size of the second aerosol generation segment. Thereby, the manufacture of the aerosol generating rod may be simplified.

[0097] Preferably, the density of the second aerosol generation substrate is substantially equal to the density of the first aerosol generation substrate. Thereby, advantageously, the manufacture of the aerosol generating rod may be simplified.

[0098] The term "density" as used herein in relation to the aerosol generation substrate refers to the bulk density of the aerosol generation substrate. This can be calculated by measuring the total weight of the aerosol generation substrate and dividing this by the volume of the segments of the aerosol generation substrate (excluding the wrapper).

[0099] Preferably, the density of the second aerosol generation substrate is within 50 mg per cubic centimeter of the density of the first aerosol generation substrate, or within 30 mg per cubic centimeter of the density of the first aerosol generation substrate, or within 10 mg per cubic centimeter of the density of the first aerosol generation substrate.

[0100] Preferably, the density of the second aerosol generation substrate is within 10 percent of the density of the first aerosol generation substrate, or within 5 percent of the density of the first aerosol generation substrate, or within 3 percent of the density of the first aerosol generation substrate.

[0101] The relative densities of the first aerosol generation substrate and the second aerosol generation substrate can be selected to optimize aerosol delivery.

[0102] In some embodiments, the density of the second aerosol generation substrate may be greater than the density of the first aerosol generation substrate.

[0103] In some embodiments, the density of the second aerosol generation substrate may be at least 100 mg per cubic centimeter higher than the density of the first aerosol generation substrate, or at least 150 mg per cubic centimeter higher than the density of the first aerosol generation substrate, or at least 200 mg per cubic centimeter higher than the density of the first aerosol generation substrate. The density of the second aerosol generation substrate may be at most 500 mg per cubic centimeter higher than the density of the first aerosol generation substrate.

[0104] In some embodiments, the density of the second aerosol generation substrate may be at least 1.2 times the density of the first aerosol generation substrate, or at least 1.5 times the density of the first aerosol generation substrate, or at least 2 times the density of the first aerosol generation substrate. The density of the second aerosol generation substrate may be at most 4 times the density of the first aerosol generation substrate. In some embodiments, the density of the second aerosol generation substrate may be greater than the density of the first aerosol generation substrate.

[0105] In some embodiments, the density of the first aerosol generation substrate may be at least 100 mg higher per cubic centimeter than the density of the second aerosol generation substrate, or at least 150 mg higher per cubic centimeter than the density of the second aerosol generation substrate, or at least 200 mg higher per cubic centimeter than the density of the second aerosol generation substrate. The density of the first aerosol generation substrate may be at most 500 mg higher per cubic centimeter than the density of the second aerosol generation substrate.

[0106] In some embodiments, the density of the first aerosol generation substrate may be at least 1.2 times the density of the second aerosol generation substrate, or at least 1.5 times the density of the second aerosol generation substrate, or at least 2 times the density of the second aerosol generation substrate. The density of the first aerosol generation substrate may be at most 4 times the density of the second aerosol generation substrate.

[0107] Preferably, the density of the first aerosol generation substrate is at least 100 mg per cubic centimeter. More preferably, the density of the first aerosol generation substrate is at least 150 mg per cubic centimeter. More preferably, the density of the first aerosol generation substrate is at least 200 mg per cubic centimeter.

[0108] Preferably, the density of the first aerosol generation substrate is 500 mg or less per cubic centimeter. More preferably, the density of the first aerosol generation substrate is 450 mg or less per cubic centimeter. More preferably, the density of the first aerosol generation substrate is 400 mg or less per cubic centimeter.

[0109] For example, the density of the first aerosol generation substrate is preferably 100 mg per cubic centimeter to 500 mg per cubic centimeter, or 100 mg per cubic centimeter to 450 mg per cubic centimeter, or 100 mg per cubic centimeter to 400 mg per cubic centimeter, or 150 mg per cubic centimeter to 500 mg per cubic centimeter, or 150 mg per cubic centimeter to 450 mg per cubic centimeter, or 150 mg per cubic centimeter to 400 mg per cubic centimeter, or 200 mg per cubic centimeter to 500 mg per cubic centimeter, or 200 mg per cubic centimeter to 450 mg per cubic centimeter, or 200 mg per cubic centimeter to 400 mg per cubic centimeter.

[0110] Preferably, the density of the second aerosol generation substrate is at least 100 mg per cubic centimeter. More preferably, the density of the second aerosol generation substrate is at least 150 mg per cubic centimeter. More preferably, the density of the second aerosol generation substrate is at least 200 mg per cubic centimeter.

[0111] Preferably, the density of the second aerosol generation substrate is 500 mg or less per cubic centimeter. More preferably, the density of the second aerosol generation substrate is 450 mg or less per cubic centimeter. More preferably, the density of the second aerosol generation substrate is 400 mg or less per cubic centimeter.

[0112] For example, the density of the second aerosol generation substrate is preferably from 100 mg per cubic centimeter to 500 mg per cubic centimeter, or from 100 mg per cubic centimeter to 450 mg per cubic centimeter, or from 100 mg per cubic centimeter to 400 mg per cubic centimeter, or from 150 mg per cubic centimeter to 500 mg per cubic centimeter, or from 150 mg per cubic centimeter to 450 mg per cubic centimeter, or from 150 mg per cubic centimeter to 400 mg per cubic centimeter, or from 200 mg per cubic centimeter to 500 mg per cubic centimeter, or from 200 mg per cubic centimeter to 450 mg per cubic centimeter, or from 200 mg per cubic centimeter to 400 mg per cubic centimeter.

[0113] Preferably, the first aerosol generation substrate is a solid aerosol generation substrate. Preferably, the second aerosol generation substrate is a solid aerosol generation substrate.

[0114] Preferably, the first aerosol generation substrate has substantially the same composition as the second aerosol generation substrate. This may simplify the manufacture of the aerosol generation rod.

[0115] The first aerosol generation substrate preferably includes one or more aerosol formers. The second aerosol generation substrate preferably includes one or more aerosol formers.

[0116] The aerosol former can be any suitable known compound or mixture of compounds that promotes the formation of a dense and stable aerosol during use. The aerosol former can promote the aerosol being substantially resistant to thermal decomposition at the temperatures typically applied during use of the aerosol generating article. Suitable aerosol formers are, for example, polyhydric alcohols such as triethylene glycol, 1,3 - butanediol, propylene glycol and glycerin, esters of polyhydric alcohols such as glycerol mono -, di - or triacetate, aliphatic esters of mono -, di - or polycarboxylic acids such as dimethyldodecanedioate and dimethyldodecanedioate, and combinations thereof.

[0117] Preferably, one or more aerosol formers comprise one or both of glycerol and propylene glycol. One or more aerosol formers can consist of one or both of glycerol and propylene glycol.

[0118] Preferably, one or both of the first aerosol generating substrate and the second aerosol generating substrate comprise glycerol.

[0119] The first aerosol generating substrate and the second aerosol generating substrate may contain the same aerosol former (or aerosol formers) as each other, or different aerosol formers may be used.

[0120] Preferably, the aerosol former content of the first aerosol generating substrate is substantially equal to the aerosol former content of the second aerosol generating substrate on a dry weight basis. This can advantageously simplify the manufacture of the aerosol generating rod in some cases.

[0121] Preferably, the aerosol-forming agent content of the second aerosol-generating substrate is within 5 percentage points of the aerosol-forming agent content of the first aerosol-generating substrate. For example, if the first aerosol-generating substrate has an aerosol-forming agent content of 20% by weight on a dry weight basis and the aerosol-forming agent content of the second aerosol-generating substrate is within 5 percentage points of the aerosol-forming agent content of the first aerosol-generating substrate, the second aerosol-generating substrate has an aerosol-forming agent content of 15% to 25% by weight on a dry weight basis.

[0122] Preferably, the aerosol-forming agent content of the second aerosol-generating substrate is within 3 percentage points of the aerosol-forming agent content of the first aerosol-generating substrate, or within 1 percentage point of the aerosol-forming agent content of the first aerosol-generating substrate.

[0123] Preferably, the aerosol-forming agent content of the second aerosol-generating substrate is within 10% of the aerosol-forming agent content of the first aerosol-generating substrate. For example, if the first aerosol-generating substrate has an aerosol-forming agent content of 20% by weight on a dry weight basis and the aerosol-forming agent content of the second aerosol-generating substrate is within 10% of the aerosol-forming agent content of the first aerosol-generating substrate, the second aerosol-generating substrate has an aerosol-forming agent content of 18% to 22% by weight on a dry weight basis.

[0124] Preferably, the aerosol-forming agent content of the second aerosol-generating substrate is within 5% of the aerosol-forming agent content of the first aerosol-generating substrate, or within 3% of the aerosol-forming agent content of the first aerosol-generating substrate.

[0125] Preferably, the glycerol content of the first aerosol-generating substrate is substantially equal to the glycerol content of the second aerosol-generating substrate on a dry weight basis. This may advantageously simplify the manufacture of the aerosol-generating rod.

[0126] Preferably, the glycerol content of the second aerosol generating substrate is within 5 percentage points of the glycerol content of the first aerosol generating substrate, or within 3 percentage points of the glycerol content of the first aerosol generating substrate, or within 1 percentage point of the glycerol content of the first aerosol generating substrate.

[0127] Preferably, the glycerol content of the second aerosol generating substrate is within 10 percent of the glycerol content of the first aerosol generating substrate, or within 5 percent of the glycerol content of the first aerosol generating substrate, or within 3 percent of the glycerol content of the first aerosol generating substrate.

[0128] The relative aerosol former contents of the first and second aerosol generating substrates may be selected to optimize aerosol delivery.

[0129] In some embodiments, the aerosol former content of the second aerosol generating substrate may be greater than the aerosol former content of the first aerosol generating substrate on a dry weight basis.

[0130] In some embodiments, the aerosol former content of the second aerosol generating substrate may be at least 15 percentage points higher than the aerosol former content of the first aerosol generating substrate. For example, the first aerosol generating substrate contains 20 weight percent of the aerosol former on a dry weight basis, the aerosol former content of the second aerosol generating substrate is at least 15 percentage points higher than the aerosol former content of the first aerosol generating substrate, and the second aerosol generating substrate contains at least 35 weight percent of the aerosol former on a dry weight basis.

[0131] The aerosol former content of the second aerosol - generating substrate is at least 20 percentage points higher than the aerosol former content of the first aerosol - generating substrate, or may be at least 25 percentage points higher than the aerosol former content of the first aerosol - generating substrate, on a dry weight basis. The aerosol former content of the second aerosol - generating substrate may be up to 60 percentage points higher than the aerosol former content of the first aerosol - generating substrate.

[0132] In some embodiments, the aerosol former content of the second aerosol - generating substrate is at least 1.2 times, or at least 1.5 times, or at least 2 times the aerosol former content of the first aerosol - generating substrate, on a dry weight basis. The aerosol former content of the second aerosol - generating substrate may be up to 4 times the aerosol former content of the first aerosol - generating substrate.

[0133] In some embodiments, the aerosol former content of the first aerosol - generating substrate may be greater than the aerosol former content of the second aerosol - generating substrate, on a dry weight basis.

[0134] In some embodiments, the aerosol former content of the first aerosol - generating substrate is at least 15 percentage points higher, or at least 20 percentage points higher, or at least 25 percentage points higher than the aerosol former content of the second aerosol - generating substrate, on a dry weight basis. The aerosol former content of the first aerosol - generating substrate may be up to 60 percentage points higher than the aerosol former content of the second aerosol - generating substrate.

[0135] In some embodiments, the aerosol former content of the first aerosol-generating substrate is at least 1.2 times, or at least 1.5 times, or at least 2 times the aerosol former content of the second aerosol-generating substrate on a dry weight basis. The aerosol former content of the first aerosol-generating substrate may be up to 4 times the aerosol former content of the second aerosol-generating substrate.

[0136] Preferably, the first aerosol-generating substrate comprises at least 5 wt% aerosol former, more preferably at least 7 wt% aerosol former, and even more preferably at least 10 wt% aerosol former on a dry weight basis of the first aerosol-generating substrate.

[0137] Preferably, the first aerosol-generating substrate comprises up to 80 wt% aerosol former on a dry weight basis of the first aerosol-generating substrate. More preferably, the first aerosol-generating substrate comprises up to 60 wt% aerosol former on a dry weight basis of the first aerosol-generating substrate. Even more preferably, the first aerosol-generating substrate comprises up to 40 wt% aerosol former on a dry weight basis of the first aerosol-generating substrate. In some embodiments, the first aerosol-generating substrate may comprise up to 20 wt% or up to 15 wt% aerosol former on a dry weight basis of the first aerosol-generating substrate.

[0138] For example, the first aerosol generation substrate contains an aerosol forming body in an amount of 5 wt% to 80 wt%, or 5 wt% to 60 wt%, or 5 wt% to 40 wt%, or 5 wt% to 20 wt%, or 5 wt% to 15 wt%, or 7 wt% to 80 wt%, or 7 wt% to 60 wt%, or 7 wt% to 40 wt%, or 7 wt% to 20 wt%, or 7 wt% to 15 wt%, or 10 wt% to 80 wt%, or 10 wt% to 60 wt%, or 10 wt% to 40 wt%, or 10 wt% to 20 wt%, or 10 wt% to 15 wt% based on the dry weight of the first aerosol generation substrate.

[0139] Preferably, the second aerosol generation substrate contains at least 5 wt% of an aerosol forming body based on the dry weight of the second aerosol generation substrate, more preferably at least 7 wt% of an aerosol forming body based on the dry weight of the second aerosol generation substrate, and at least 10 wt% of an aerosol forming body based on the dry weight of the second aerosol generation substrate.

[0140] Preferably, the second aerosol generation substrate contains 80 wt% or less of an aerosol forming body based on the dry weight of the second aerosol generation substrate. More preferably, the second aerosol generation substrate contains 60 wt% or less of an aerosol forming body based on the dry weight of the second aerosol generation substrate. More preferably, the second aerosol generation substrate contains 40 wt% or less of an aerosol forming body based on the dry weight of the second aerosol generation substrate. In some preferred embodiments, the second aerosol generation substrate may contain 20 wt% or less, or 15 wt% or less of an aerosol forming body based on the dry weight of the second aerosol generation substrate.

[0141] For example, the second aerosol generation substrate contains an aerosol forming body in an amount of 5 wt% to 80 wt%, or 5 wt% to 60 wt%, or 5 wt% to 40 wt%, or 5 wt% to 20 wt%, or 5 wt% to 15 wt%, or 7 wt% to 80 wt%, or 7 wt% to 60 wt%, or 7 wt% to 40 wt%, or 7 wt% to 20 wt%, or 7 wt% to 20 wt%, or 10 wt% to 80 wt%, or 10 wt% to 60 wt%, or 10 wt% to 40 wt%, or 10 wt% to 20 wt%, or 10 wt% to 15 wt% based on the dry weight of the second aerosol generation substrate.

[0142] Preferably, the first aerosol generation substrate and the second aerosol generation substrate are formed of the same type of substrate material. Suitable types of materials for use in the aerosol generating articles of the present invention are described below and include, for example, homogenized tobacco materials such as tobacco cut filler, cast leaf, aerosol generating films and gel compositions. The first aerosol generation substrate and the second aerosol generation substrate may be formed of different types of materials.

[0143] Preferably, the first aerosol generation substrate contains a tobacco material. In certain preferred embodiments, the first aerosol generation substrate contains shredded tobacco material. For example, the shredded tobacco material may be in the form of cut filler, as will be described in more detail below. Alternatively, the shredded tobacco material may be in the form of shredded sheets of homogenized tobacco material. Suitable homogenized tobacco materials for use in the present invention are described below.

[0144] 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, including one or more of the lamina of the leaf, processed stem and veins, and homogenized plant material.

[0145] The cut filler may also comprise other post-cut materials, filler tobacco, or casing.

[0146] Preferably, the cut filler comprises at least 25 percent leaf lamina of plant leaves, more preferably at least 50 percent leaf lamina of plant leaves, even more preferably at least 75 percent leaf lamina of plant leaves, and most preferably at least 90 percent leaf lamina of plant leaves. Preferably, the plant material is one of tobacco, mint, tea, and clove. Most preferably, the plant material is tobacco. However, the present invention is equally applicable to other plant materials that have the ability to release substances upon heating and then form an aerosol.

[0147] Preferably, the cut filler comprises tobacco plant material comprising leaf lamina of one or more of bright tobacco, dark tobacco, aromatic tobacco, and filler tobacco. For the purposes of the present invention, the term "tobacco" describes any plant of the Nicotiana genus.

[0148] The cut filler suitable for use in the present invention may generally be similar to the cut filler used in conventional smoking articles. The cut width of the cut filler is preferably from 0.3 millimeters to 2.0 millimeters, or may be from 0.5 millimeters to 1.2 millimeters, or from 0.6 millimeters to 0.9 millimeters.

[0149] Preferably, the strands have a length of from about 10 millimeters to about 40 millimeters before being arranged to form the aerosol-generating rod.

[0150] In a preferred embodiment, the weight of the cut filler is from 80 milligrams to 400 milligrams, preferably from 120 milligrams to 250 milligrams, more preferably from 150 milligrams to 200 milligrams. This amount of cut filler typically allows for sufficient material for aerosol formation.

[0151] Preferably, the cut filler is impregnated with an aerosol former. The impregnation of the cut filler can be carried out by spraying or other suitable application methods. The aerosol former can be added to the blend during the preparation of the cut filler. For example, the aerosol former may be applied directly to the blend in a direct conditioning casing cylinder (DCCC). Conventional machinery can be used to apply the aerosol former to the cut filler. Suitable aerosol formers are presented above.

[0152] Preferably, the aerosol former in the cut filler comprises one or both of glycerol and propylene glycol. The aerosol former may consist of glycerol or propylene glycol, or a combination of glycerol and propylene glycol.

[0153] In another preferred embodiment, the first aerosol-generating substrate comprises homogenized plant material, preferably homogenized tobacco material.

[0154] 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 plant material for use in the aerosol-generating substrate of the present invention can be formed by aggregating plant material particles obtained by grinding, crushing, or finely comminuting the plant material. The homogenized plant material can be produced by casting, extrusion, a papermaking process, or any other suitable process known in the art.

[0155] The homogenized plant material can be provided in any suitable form.

[0156] In some embodiments, the homogenized plant material may be in the form of one or more sheets. As used herein in the context of the present invention, the term "sheet" describes a layered element having a width and length that are substantially greater than its thickness.

[0157] The homogenized plant material may be in the form of a plurality of pellets or granules.

[0158] The homogenized plant material may be in the form of a plurality of strands, flakes or pieces. As used herein, the term "strand" describes an elongated element of a material having a length that is substantially greater than its width and thickness. The term "strand" should be considered to encompass flakes, pieces, and any other homogenized plant material having a similar form. Strands of the homogenized plant material can be formed from a sheet of the homogenized plant material, for example by cutting or shredding, or by other means, such as extrusion.

[0159] As described above, when the homogenized plant material is in the form of one or more sheets, the sheets may be created by a casting process. Alternatively, the sheets of the homogenized plant material may be manufactured by a papermaking process.

[0160] One or more sheets as described herein may each individually have a thickness of from 100 micrometers to 600 micrometers, preferably from 150 micrometers to 300 micrometers, and most preferably from 200 micrometers to 250 micrometers. The individual thickness refers to the thickness of an individual sheet, and the combined thickness refers to the total thickness of all the sheets that make up the aerosol generating substrate.

[0161] One or more sheets as described herein may each individually have a basis weight of from 100 grams per square meter to 600 grams per square meter.

[0162] One or more sheets as described herein may each individually have a density of from 0.3 grams per cubic centimeter to 1.3 grams per cubic centimeter, preferably from 0.7 grams per cubic centimeter to 1.0 grams per cubic centimeter.

[0163] One or more sheets as described herein may be one or more of those subjected to crimping, folding, gathering, and pleating.

[0164] One or more sheets of homogenized plant material may be cut into strands as mentioned above. In such embodiments, the first aerosol-generating substrate comprises a plurality of strands of homogenized plant material. The strands can be used to form plugs. Typically, the width of such strands is about 5 millimeters, or about 4 millimeters, or about 3 millimeters, or about 2 millimeters or less. The length of the strands may be longer than about 5 millimeters, may be about 5 millimeters to about 15 millimeters, may be about 8 millimeters to about 12 millimeters, or may be about 12 millimeters. Preferably, the strands have substantially the same length as each other.

[0165] For example, the homogenized plant material may contain, on a dry weight basis, 2.5 weight percent to 95 weight percent plant particles, or 5 weight percent to 90 weight percent plant particles, or 10 weight percent to 80 weight percent plant particles, or 15 weight percent to 70 weight percent plant particles, or 20 weight percent to 60 weight percent plant particles, or 30 weight percent to 50 weight percent plant particles.

[0166] In certain embodiments of the present invention, the homogenized plant material is a homogenized tobacco material containing tobacco particles. The sheet of homogenized tobacco material used in such embodiments of the present invention may have a tobacco content of at least about 40 weight percent, more preferably at least about 50 weight percent, more preferably at least about 70 weight percent, and most preferably at least about 90 weight percent on a dry weight basis.

[0167] With respect to the present invention, the term "tobacco particle" describes particles of any plant member of the genus Nicotiana. The term "tobacco particle" includes the leaf blade of ground or powdered tobacco leaf, the stem of ground or powdered tobacco leaf, tobacco dust, tobacco fines, and other particulate tobacco by-products formed during the processing, handling, and shipping of tobacco. In a preferred embodiment, the tobacco particles are substantially all derived from the leaf blade of the tobacco leaf. In contrast, isolated nicotine and nicotine salts are compounds derived from tobacco but are not considered tobacco particles for the purposes of the present invention and are not included in the proportion of particulate plant material.

[0168] In a preferred embodiment, the first aerosol generating substrate comprises strands of homogenized tobacco material, and the weight of the strands of homogenized tobacco material is from 80 milligrams to 400 milligrams, preferably from 120 milligrams to 250 milligrams, more preferably from 150 milligrams to 200 milligrams. This amount of strands of homogenized tobacco material typically allows sufficient material for aerosol formation.

[0169] In a preferred embodiment, the second aerosol generating substrate comprises strands of homogenized tobacco material, and the weight of the strands of homogenized tobacco material is from 80 milligrams to 400 milligrams, preferably from 120 milligrams to 250 milligrams, more preferably from 150 milligrams to 200 milligrams.

[0170] In some embodiments, the first aerosol generating substrate may be in the form of an aerosol generating film comprising a cellulose-based film former, nicotine, and one or more aerosol formers. The aerosol generating film may further comprise a cellulose-based strengthening agent. The aerosol generating film may further contain less than 30 weight percent water.

[0171] As used herein, the term "film" is used to describe a solid, layered element having a thickness that is small relative to its width or length. The film may be self-supporting. In other words, the film may have cohesive and mechanical properties such that it can be separated from the support surface even if it is obtained by casting a film-forming formulation on the support surface. Alternatively, the film may be disposed on a support or sandwiched between other materials. This can enhance the mechanical stability of the film.

[0172] The aerosol-forming agent content of the aerosol-generating film may be within the range defined above for the first aerosol-generating substrate.

[0173] In the context of the present invention, the term "cellulosic film-forming agent" is used to describe a cellulose polymer that has the ability to form a continuous film, either by itself or in the presence of an auxiliary thickener.

[0174] Preferably, the cellulosic film-forming agent is selected from the group consisting of hydroxypropyl methylcellulose (HPMC), methylcellulose (MC), ethylcellulose (EC), hydroxyethyl methylcellulose (HEMC), hydroxyethylcellulose (HEC), hydroxypropylcellulose (HPC), and combinations thereof.

[0175] More preferably, the cellulosic film-forming agent is selected from the group consisting of hydroxypropyl methylcellulose (HPMC), methylcellulose (MC), ethylcellulose (EC), and combinations thereof.

[0176] In a particularly preferred embodiment, the cellulosic film-forming agent is HPMC.

[0177] As used herein in connection with the present invention, the term "nicotine" is used to describe nicotine, nicotine base, or a nicotine salt. In embodiments where the aerosol generating film contains a nicotine base or a nicotine salt, the amounts of nicotine recited herein are the amounts of free base nicotine or protonated nicotine, respectively.

[0178] In an alternative embodiment of the present invention, the first aerosol generating substrate may comprise a gel composition comprising nicotine, at least one gelling agent, and an aerosol former. The gel composition preferably contains substantially no tobacco.

[0179] The gel composition preferably contains at least one gelling agent. Preferably, the gel composition contains a total amount of gelling agent in the range of about 0.4 weight percent to about 10 weight percent, or about 0.5 weight percent to about 8 weight percent, or about 1 weight percent to about 6 weight percent, or about 2 weight percent to about 4 weight percent, or about 2 weight percent to about 3 weight percent.

[0180] The term "gelling agent" refers to a compound that, when added in an amount of about 0.3 weight percent to a homogeneous mixture of 50 weight percent water / 50 weight percent glycerol, forms a solid medium or support matrix leading to a gel. Examples of gelling agents include, but are not limited to, hydrogen bond cross-linked gelling agents and ion cross-linked gelling agents.

[0181] The term "hydrogen bond cross-linked gelling agent" refers to a gelling agent that forms non-covalent cross-links or physical cross-links via hydrogen bonds.

[0182] The hydrogen bond cross-linked gelling agent may include one or more of galactomannan, gelatin, agarose, konjac gum, or agar. The hydrogen bond cross-linked gelling agent preferably may include agar.

[0183] The term "ionic crosslinking gelling agent" refers to a gelling agent that forms non-covalent crosslinking bonds or physical crosslinking bonds via ionic bonds.

[0184] The ionic crosslinking gelling agent may include low acyl gellan, pectin, kappa-carrageenan, iota-carrageenan or alginate. The ionic crosslinking gelling agent may preferably include low acyl gellan.

[0185] The gelling agent may include one or more biopolymers. The biopolymer may be formed of a polysaccharide.

[0186] Examples of biopolymers include, for example, gellan gum (natural gellan gum, low acyl gellan gum, high acyl gellan gum, low acyl gellan gum is preferred), xanthan gum, alginate (alginic acid), agar, guar gum, and the like. The composition preferably includes xanthan gum. The composition may include two biopolymers. The composition may include three biopolymers. The composition may include two biopolymers in substantially equal weights. The composition may include three biopolymers in substantially equal weights.

[0187] As described above, the second aerosol generating substrate may be in the form of a cut filler, or a homogenized tobacco material such as a cast leaf, or an aerosol generating film, or a gel composition.

[0188] Preferably, the second aerosol generating substrate includes tobacco. In certain preferred embodiments, the second aerosol generating substrate includes shredded tobacco material. For example, as described above, the shredded tobacco material may be in the form of a cut filler. As another example, the shredded tobacco material may be in the form of a shredded sheet of homogenized tobacco material as described above.

[0189] In certain embodiments of the present invention, the aerosol-generating article further includes one or more elongated susceptor elements within the aerosol-generating rod. For example, the one or more elongated susceptor elements may be disposed substantially longitudinally within the aerosol-generating rod and may be in thermal contact with the aerosol-generating substrate. When the aerosol-generating rod comprises one or more elongated susceptor elements, one or both of the first aerosol-generating segment and the second aerosol-generating segment may include a susceptor element extending longitudinally therein. In such an arrangement, separate susceptor elements may be provided within the first aerosol-generating segment and the second aerosol-generating segment.

[0190] As used herein with respect to the present invention, the term "susceptor element" refers to a material capable of converting electromagnetic energy into heat. When positioned within a varying electromagnetic field, the induced eddy currents in the susceptor element cause heating of the susceptor element. Since the susceptor element is positioned in thermal contact with the aerosol-generating substrate, the aerosol-generating substrate is heated by the susceptor element.

[0191] When used to describe a susceptor element, the term "elongated" means that the susceptor element has a length dimension that is greater than its width dimension or its thickness dimension, for example, more than twice its width dimension or its thickness dimension.

[0192] The susceptor element may be disposed substantially longitudinally within the rod or segment. This means that the length dimension of the elongated susceptor element may be disposed substantially parallel to the longitudinal axis of the rod, for example, within ±10 degrees parallel to the longitudinal axis of the rod. In a preferred embodiment, the elongated susceptor element may be positioned radially centrally within the rod or segment and extends along the longitudinal axis of the rod or segment.

[0193] The susceptor element is preferably in the form of a pin, rod, strip, or blade.

[0194] The susceptor element preferably has a width of from 1 millimeter to 5 millimeters.

[0195] The susceptor element may generally have a thickness of from 0.01 millimeter to 2 millimeters, such as from 0.5 millimeter to 2 millimeters. In some embodiments, the susceptor element preferably has a thickness of from 10 micrometers to 500 micrometers, more preferably from 10 micrometers to 100 micrometers.

[0196] Preferably, the elongated susceptor element has a length that is the same as or shorter than the length of the aerosol generating substrate into which it is incorporated. Preferably, the elongated susceptor element has the same length as the aerosol generating substrate into which it is incorporated.

[0197] The susceptor element can be formed from any material that can be inductively heated to a temperature sufficient to generate an aerosol from the aerosol generating substrate. Preferred susceptor elements include metal or carbon.

[0198] Preferred susceptor elements may include ferromagnetic materials such as ferromagnetic alloys, ferrite iron, or ferromagnetic steel, or stainless steel, or may consist of ferromagnetic materials. Suitable susceptor elements may be aluminum or may include aluminum.

[0199] Suitable susceptor elements may comprise a non-metallic core and a metal layer disposed on the non-metallic core, such as a metal track formed on the surface of a ceramic core. The susceptor element may have a protective outer layer that encapsulates the susceptor element, such as a protective ceramic layer or a protective glass layer. The susceptor element may comprise a protective coating formed of glass, ceramic, or an inert metal formed on the core of the susceptor element material.

[0200] The susceptor element is disposed in thermal contact with the aerosol generating substrate of the aerosol generating segment in which the susceptor element is incorporated. Therefore, when the temperature of the susceptor element rises, the aerosol generating substrate is heated and aerosol is formed. Preferably, the susceptor element is disposed in physical and direct contact with the aerosol generating substrate, for example, within the aerosol generating substrate.

[0201] Preferably, the first aerosol generating substrate is surrounded by a first wrapper. Preferably, the second aerosol generating substrate is surrounded by a second wrapper.

[0202] When the first aerosol generating substrate is surrounded by a first wrapper and the second aerosol generating substrate is surrounded by a second wrapper, preferably, the second wrapper is separated from the first wrapper. Thus, each of the aerosol generating segments may have a unique and separate plug wrapper around each respective aerosol generating substrate.

[0203] An aerosol generating rod including a first aerosol generating segment and a second aerosol generating segment may be surrounded by a further wrapper that combines the aerosol generating segments and holds them in a predetermined position relative to each other.

[0204] The wrapper surrounding the aerosol generating rod can be a paper wrapper or a non - paper wrapper. Suitable paper wrappers for use in particular embodiments of the present invention are known in the art and include, but are not limited to, cigarette paper and filter plug wrap. Suitable non - paper wrappers for use in particular embodiments of the present invention are known in the art and include, but are not limited to, sheets of homogenized tobacco material.

[0205] The paper wrapper may have a basis weight of 15 gsm to 35 gsm, preferably 20 gsm to 30 gsm.

[0206] The paper wrapper may have a thickness of 25 micrometers to 55 micrometers, preferably 30 micrometers to 50 micrometers, more preferably 35 micrometers to 45 micrometers.

[0207] In certain preferred embodiments, the wrapper may be formed from a laminated material comprising a plurality of layers. Preferably, the wrapper is formed from an aluminum coextruded sheet.

[0208] The paper layer of the coextruded sheet may have a basis weight of 35 gsm to 55 gsm, preferably 40 gsm to 50 gsm.

[0209] The paper layer of the coextruded sheet may have a thickness of 50 micrometers to 80 micrometers, preferably 55 micrometers to 75 micrometers, more preferably 60 micrometers to 70 micrometers.

[0210] The metal layer of the coextruded sheet may have a basis weight of 12 gsm to 25 gsm, preferably 15 gsm to 20 gsm.

[0211] The metal layer of the coextruded sheet may have a thickness of 2 micrometers to 15 micrometers, preferably 3 micrometers to 12 micrometers, more preferably 5 micrometers to 10 micrometers.

[0212] The wrapper surrounding the aerosol generating rod can be a paper wrapper containing PVOH (polyvinyl alcohol) or silicone (or polysiloxane). The addition of PVOH (polyvinyl alcohol) or silicone (or polysiloxane) may improve the grease barrier properties of the wrapper.

[0213] The paper wrapper containing PVOH or silicone (or polysiloxane) may have a basis weight of 20 gsm to 50 gsm, preferably 25 gsm to 45 gsm, more preferably 30 gsm to 40 gsm.

[0214] The paper wrapper containing PVOH or silicone (or polysiloxane) may have a thickness of 25 micrometers to 50 micrometers, preferably 30 micrometers to 45 micrometers, more preferably 35 micrometers to 40 micrometers.

[0215] The wrapper surrounding the aerosol generating rod may contain a flame retardant composition comprising one or more flame retardant compounds. The term "flame retardant compound" as used herein describes a compound that provides varying degrees of flammability protection to a carrier substrate when added to or otherwise incorporated into a carrier substrate such as a paper or plastic compound.

[0216] Numerous suitable flame retardant compounds are known to those skilled in the art. In particular, several flame retardant compounds and formulations suitable for treating cellulosic materials are known and disclosed and may find use in the manufacture of wrappers for aerosol generating articles according to the present invention.

[0217] The wrapper containing the flame retardant composition may have a basis weight of 20 gsm to 45 gsm, preferably 25 gsm to 40 gsm, more preferably 30 gsm to 35 gsm.

[0218] The wrapper containing the flame retardant composition may have a thickness of at least 25 micrometers, preferably at least 30 micrometers, even more preferably at least 35 micrometers. The wrapper containing the flame retardant composition may have a thickness of 50 micrometers or less, preferably 45 micrometers or less, even more preferably 40 micrometers or less.

[0219] The aerosol-generating article according to the present invention preferably further comprises a downstream section located downstream of the aerosol-generating rod. The downstream section is preferably located immediately downstream of the aerosol-generating rod. The downstream section of the aerosol-generating article preferably extends between the aerosol-generating rod and the downstream end of the aerosol-generating article. The downstream section may comprise one or more elements, each of which is described in more detail within the present disclosure.

[0220] The length of the downstream section may be at least 20 millimeters, or at least 25 millimeters, or at least 30 millimeters.

[0221] The length of the downstream section may be less than 70 millimeters, or less than 60 millimeters, or less than 50 millimeters.

[0222] For example, the length of the downstream section may be from 20 millimeters to 70 millimeters, or from 25 millimeters to 60 millimeters, or from 30 millimeters to 50 millimeters.

[0223] The downstream section of the aerosol-generating article according to the present invention preferably comprises a hollow tubular cooling element provided downstream of the aerosol-generating rod. The hollow tubular cooling element may advantageously provide an aerosol cooling element for the aerosol-generating article.

[0224] The hollow tubular cooling element may be provided immediately downstream of the aerosol-generating rod. In other words, the hollow tubular cooling element may abut the downstream end of the aerosol-generating rod. The hollow tubular cooling element may define the upstream end of the downstream section of the aerosol-generating article. The downstream end of the aerosol-generating article may coincide with the downstream end of the downstream section. In some embodiments, the downstream section of the aerosol-generating article comprises a single hollow tubular element. In other words, the downstream section of the aerosol-generating article may comprise only one hollow tubular element. In other embodiments, the downstream section comprises two or more hollow tubular elements as described below.

[0225] As used throughout this disclosure, the term "hollow tubular element" refers to a generally elongated element that defines a lumen or air flow passage along its longitudinal axis. In particular, the term "tubular" is used hereinafter with respect to a tubular element that has a substantially cylindrical cross-section and defines at least one air flow conduit that establishes unbroken fluid communication between the upstream end of the tubular element and the downstream end of the tubular element. However, it will be understood that alternative shapes (e.g., alternative cross-sectional shapes) of the tubular element may be possible. The hollow tubular cooling element can be an individual discrete element of the aerosol generating article having a defined length and thickness.

[0226] In the context of the present invention, the hollow tubular cooling element provides a flow channel with no restrictions. This means that the hollow tubular cooling element provides a negligible level of draw resistance (RTD). The term "negligible level of RTD" is used to describe an RTD of less than 1 millimeter H2O per 10 millimeters of the length of the hollow tubular cooling element, preferably less than 0.4 millimeter H2O per 10 millimeters of the length of the hollow tubular cooling element, more preferably less than 0.1 millimeter H2O per 10 millimeters of the length of the hollow tubular cooling element.

[0227] The RTD of the hollow tubular cooling element is preferably 10 millimeters H2O or less, or 5 millimeters H2O or less, or 2.5 millimeters H2O or less, or 2 millimeters H2O or less, or 1 millimeter H2O or less.

[0228] The RTD of the hollow tubular cooling element can be at least 0 millimeter H2O, or at least 0.25 millimeter H2O, or at least 0.5 millimeter H2O, or at least 1 millimeter H2O.

[0229] In the aerosol-generating article according to the present invention, the overall RTD of the article essentially depends on the RTD of the rod and optionally the RTD of downstream and / or upstream elements. This is because the hollow tubular cooling element is substantially empty and thus contributes only substantially slightly to the overall RTD of the aerosol-generating article.

[0230] Accordingly, the flow channel should not include any component that would impede the flow of air in the longitudinal direction. Preferably, the flow channel is substantially empty, and particularly preferably, the flow channel is empty.

[0231] As described in more detail within the present disclosure, the aerosol-generating article may comprise a ventilation zone at a location along the downstream section. In some embodiments, the aerosol-generating article may comprise a ventilation zone at a location along the hollow tubular cooling element. Such, or any ventilation zone, may extend through the peripheral wall of the hollow tubular cooling element. In this way, fluid communication is established between the flow channel internally defined by the hollow tubular cooling element and the external environment. The ventilation zone is further described within the present disclosure.

[0232] The length of the hollow tubular cooling element may be at least 15 millimeters, or at least 20 millimeters, or at least 25 millimeters.

[0233] The length of the hollow tubular cooling element may be less than 50 millimeters, or less than 45 millimeters, or less than 40 millimeters.

[0234] For example, the length of the hollow tubular cooling element may be from 15 millimeters to 50 millimeters, or from 20 millimeters to 45 millimeters, or from 20 millimeters to 40 millimeters, or from 20 millimeters to 30 millimeters, or from 25 millimeters to 40 millimeters.

[0235] A relatively long hollow tubular cooling element provides and defines a relatively long internal cavity within the aerosol-generating article and downstream of the aerosol-generating rod. By providing an empty cavity downstream (preferably, immediately downstream) of the aerosol-generating substrate, the nucleation of aerosol particles generated by the substrate is enhanced. Providing a relatively long cavity maximizes the advantages of such nucleation, thereby improving aerosol formation and cooling.

[0236] The wall thickness of the hollow tubular cooling element may be from 100 micrometers to 2 millimeters, or from 150 micrometers to 1.5 millimeters, or from 200 micrometers to 1.25 millimeters.

[0237] The hollow tubular cooling element preferably has an outer diameter that is approximately equal to the outer diameter of the aerosol-generating rod and the outer diameter of the aerosol-generating article.

[0238] The hollow tubular cooling element may have an outer diameter of from 5 millimeters to 10 millimeters, such as from 5.5 millimeters to 9 millimeters, or from 6 millimeters to 8 millimeters. In certain embodiments, the hollow tubular cooling element has an outer diameter of less than 7 millimeters.

[0239] The hollow tubular cooling element may have an inner diameter. Preferably, the hollow tubular cooling element has a constant inner diameter along the length of the hollow tubular cooling element. However, the inner diameter of the hollow tubular cooling element may vary along the length of the hollow tubular cooling element.

[0240] The hollow tubular cooling element may have an inner diameter of at least 2 millimeters. For example, the hollow tubular cooling element may have an inner diameter of at least 3 millimeters, at least 4 millimeters, or at least 5 millimeters.

[0241] By providing a hollow tubular cooling element having an inner diameter as presented above, advantageously, sufficient rigidity and strength can be provided to the hollow tubular cooling element.

[0242] The hollow tubular cooling element may have an inner diameter of 10 millimeters or less. For example, the hollow tubular cooling element may have an inner diameter of 9 millimeters or less, 8 millimeters or less, or 7 millimeters or less.

[0243] Providing a hollow tubular cooling element having an inner diameter as presented above may advantageously reduce the draw resistance of the hollow tubular cooling element.

[0244] The hollow tubular cooling element may have an inner diameter of 2 millimeters to 10 millimeters, 3 millimeters to 9 millimeters, 4 millimeters to 8 millimeters, or 5 millimeters to 7 millimeters.

[0245] The lumen or cavity of the hollow tubular cooling element may have any cross-sectional shape. The lumen of the hollow tubular cooling element may have a circular cross-sectional shape.

[0246] The hollow tubular cooling element may include a paper-based material. The hollow tubular cooling element may include at least one layer of paper. The paper can be very hard paper. The paper can be curled paper such as heat-resistant curled paper or curled sulfuric acid paper.

[0247] Preferably, the hollow tubular cooling element may include cardboard. The hollow tubular cooling element can be a cardboard tube. The hollow tubular cooling element can be formed from cardboard. Advantageously, cardboard provides a balance between being deformable to facilitate the insertion of an article into the aerosol generating device and being sufficiently rigid to provide a suitable engagement of the article with the interior of the device, and is a cost-effective material. Thus, the cardboard tube may provide suitable resistance to deformation or compression during use.

[0248] The hollow tubular cooling element may be a paper tube. The hollow tubular cooling element can be a tube formed from paper wound in a spiral. The hollow tubular cooling element can be formed from a plurality of layers of paper. The paper can have a basis weight of at least 50 grams per square meter, at least 60 grams per square meter, at least 70 grams per square meter, or at least 90 grams per square meter.

[0249] The hollow tubular cooling element may include a polymeric material. For example, the hollow tubular cooling element can comprise a polymeric film. The polymeric film can include a cellulose film. The hollow tubular cooling element can include low density polyethylene (LDPE) or polyhydroxyalkanoate (PHA) fibers. The hollow tube can include cellulose acetate tow.

[0250] When the hollow tubular cooling element includes cellulose acetate tow, the cellulose acetate tow may have a denier per filament of 2 to 4 and a total denier of 25 to 40.

[0251] Preferably, the aerosol generating article according to the present invention comprises a ventilation zone at a location along the downstream section. More particularly, in those embodiments where the downstream section comprises a hollow tubular cooling element, the ventilation zone can be provided at a location along the hollow tubular cooling element. Alternatively or additionally, in those embodiments where the downstream section comprises a downstream hollow tubular element, the ventilation zone can be provided at a location along the downstream hollow tubular element.

[0252] Thus, a vented cavity is provided downstream of the aerosol generating rod. This provides several potential technical advantages. First, the inventors have found that one such vented hollow tubular cooling element provides particularly efficient cooling of the aerosol. Second, the inventors have surprisingly found that such rapid cooling of the volatile species released upon heating of the aerosol generating substrate enhances the nucleation of aerosol particles.

[0253] The ventilation zone can typically include a plurality of perforations through the peripheral wall of the hollow tubular cooling element. Preferably, the ventilation zone includes at least one circumferential row of perforations. In some embodiments, the ventilation zone can include two circumferential rows of perforations. For example, the perforations can be formed online during the manufacture of the aerosol generating article. Preferably, each circumferential row of perforations includes from 8 to 30 perforations.

[0254] The aerosol generating article according to the present invention has a ventilation level of at least 40 percent. By increasing the ventilation level, the level of aerosol cooling can be increased. However, increasing the ventilation level may mean that less air enters the aerosol generating article through the upstream end of the aerosol generating article and then flows through the aerosol generating rod. Accordingly, the ventilation level can be selected based on the desired temperature and composition of the aerosol delivered to the user.

[0255] The aerosol generating article preferably has a ventilation level of at least 45 percent, more preferably at least 50 percent, more preferably at least 60 percent, more preferably at least 70 percent.

[0256] The aerosol generating article according to the present invention may have a ventilation level of 90 percent or less, more preferably 85 percent or less, more preferably 80 percent or less.

[0257] Therefore, the aerosol generating article according to the present invention may have a ventilation level of 45 percent to 90 percent, more preferably 45 percent to 85 percent, even more preferably 45 percent to 80 percent. The aerosol generating article according to the present invention may have a ventilation level of 50 percent to 90 percent, preferably 50 percent to 85 percent, more preferably 50 percent to 80 percent. The aerosol generating article according to the present invention may have a ventilation level of 60 percent to 90 percent, preferably 60 percent to 85 percent, more preferably 60 percent to 80 percent. The aerosol generating article according to the present invention may have a ventilation level of 70 percent to 90 percent, preferably 70 percent to 85 percent, more preferably 70 percent to 80 percent.

[0258] For example, the aerosol generating article may have a ventilation level of about 75 percent.

[0259] As discussed in the present disclosure, the downstream section may comprise a downstream filter segment. The downstream filter segment may extend to the downstream end of the downstream section. The downstream filter segment may be located at the downstream end of the aerosol generating article. The downstream end of the downstream filter segment may define the downstream end of the aerosol generating article.

[0260] The downstream filter segment may be located downstream of the hollow tubular cooling element, as described above. The downstream filter segment may extend between the hollow tubular cooling element and the downstream end of the aerosol generating article.

[0261] The downstream filter segment is preferably a solid plug, which may also be described as a "plane" plug and is non-tubular. Thus, the filter segment preferably has a substantially uniform cross-section.

[0262] The downstream filter segment is formed of a fibrous filter material. The fibrous filter material can be for filtering the aerosol generated from the aerosol generating substrate. Suitable fibrous filter materials will be known to those skilled in the art. Particularly preferably, at least one downstream filter segment comprises a cellulose acetate filter segment formed from cellulose acetate tow.

[0263] In certain preferred embodiments, the downstream section includes a single downstream filter segment. In alternative embodiments, the downstream section includes two or more downstream filter segments axially aligned in an end-to-end abutting relationship with each other.

[0264] The downstream filter segment can optionally include a flavorant provided in any suitable form. For example, the downstream filter segment can comprise one or more capsules, beads, or granules of flavorant, or threads or filaments filled with one or more flavors.

[0265] Preferably, the downstream filter segment has a low particle filtration efficiency.

[0266] Preferably, the downstream filter segment is surrounded by a plug wrap. Preferably, the downstream filter segment is not ventilated so that air does not enter the aerosol generating article along the downstream filter segment.

[0267] The downstream filter segment is preferably connected by a tipping wrapper to one or more of the adjacent upstream components of the aerosol generating article.

[0268] The downstream filter segment preferably has an outer diameter that is approximately equal to the outer diameter of the aerosol generating article. The outer diameter of the downstream filter segment may be substantially the same as the outer diameter of the hollow tubular cooling element.

[0269] The outer diameter of the downstream filter segment may be 5 millimeters to 10 millimeters, or 5.5 millimeters to 9 millimeters, or 6 millimeters to 8 millimeters. In certain embodiments, the exterior of the downstream filter segment is less than 7 millimeters.

[0270] Unless otherwise specified, the draw resistance (RTD) of a component or aerosol-generating article is measured in accordance with ISO6565-2015. 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". Such terms generally refer to measurements in accordance with ISO6565-2015 that are normally carried out at a temperature of 22 degrees Celsius, a pressure of 101 kPa (about 760 Torr), and a relative humidity of 60%, at a volumetric flow rate of 17.5 milliliters per second at the output or downstream end of the component being measured. The conditions for smoking and the specifications of the smoking machine are presented in ISO standard 3308 (ISO3308:2000). The atmosphere for conditioning and testing is presented in ISO standard 3402 (ISO3402:1999).

[0271] The draw resistance (RTD) of the downstream section may be at least 0 millimeter H2O. The RTD of the downstream section may be at least 3 millimeters H2O. The RTD of the downstream section may be at least 6 millimeters H2O.

[0272] The RTD of the downstream section may be 12 millimeters H2O or less. The RTD of the downstream section may be 11 millimeters H2O or less. The RTD of the downstream section may be 10 millimeters H2O or less.

[0273] The draw resistance (RTD) characteristics of the downstream section may be entirely or mostly due to the RTD characteristics of the downstream filter segment of the downstream section. In other words, the RTD of the downstream filter segment of the downstream section may fully define the RTD of the downstream section.

[0274] The draw resistance (RTD) of the downstream filter segment may be at least 0 millimeter H2O, or at least 3 millimeters H2O, or at least 6 millimeters H2O.

[0275] The RTD of the downstream filter segment may be 12 millimeters H2O or less, or 11 millimeters H2O or less, or 10 millimeters H2O or less.

[0276] As described above, the downstream filter segment may be formed of a fibrous material. The downstream filter segment may be formed of a porous material. The downstream filter segment may be formed of a biodegradable material. The downstream filter segment may be formed of a cellulose material such as cellulose acetate. For example, the downstream filter segment may be formed from a bundle of cellulose acetate fibers having 10 to 15 denier per filament. For example, the downstream filter segment is formed from a relatively low density cellulose acetate tow such as cellulose acetate tow containing fibers of 12 denier per filament.

[0277] The downstream filter segment may be formed of a polylactic acid-based material. The downstream filter segment may be formed of a bioplastic material, preferably a starch-based bioplastic material. The downstream filter segment may be produced by injection molding or extrusion molding. The bioplastic-based material is advantageous because it can provide a downstream filter segment structure that is easy and inexpensive to manufacture due to a specific complex cross-sectional profile with a plurality of relatively large air flow channels extending through the downstream filter segment material that provides suitable RTD characteristics.

[0278] The length of the downstream filter segment may be at least 5 millimeters, or at least 10 millimeters. The length of the downstream filter segment may be less than 25 millimeters, or less than 20 millimeters. For example, the length of the downstream filter segment may be 5 millimeters to 25 millimeters, or 10 millimeters to 25 millimeters, or 5 millimeters to 20 millimeters, or 10 millimeters to 20 millimeters.

[0279] The downstream section may further comprise one or more additional hollow tubular elements.

[0280] In certain embodiments, the downstream section may comprise a hollow tubular support element upstream of the hollow tubular cooling element described above. Preferably, the hollow tubular support element abuts the downstream end of the aerosol generating rod. Preferably, the hollow tubular support element abuts the upstream end of the hollow tubular cooling element. Preferably, the hollow tubular support element and the hollow tubular cooling element are adjacent to each other and together provide a hollow tubular section within the downstream section.

[0281] The hollow tubular support element may be formed from any suitable material or combination of materials. For example, the support element may be formed from one or more materials selected from the group consisting of cellulose acetate, paper, crumpled paper such as crumpled heat-resistant paper or crumpled sulfuric acid paper, and polymeric materials such as low-density polyethylene (LDPE). In a preferred embodiment, the support element is formed from cellulose acetate. Other suitable materials include polyhydroxyalkanoate (PHA) fibers. In a preferred embodiment, the hollow tubular support element comprises a hollow acetate tube.

[0282] The hollow tubular support element preferably has an outer diameter that is approximately equal to the outer diameter of the aerosol generating rod and the outer diameter of the aerosol generating article.

[0283] The hollow tubular support element may have an outer diameter of 5 millimeters to 10 millimeters, for example, 5.5 millimeters to 9 millimeters, or 6 millimeters to 8 millimeters. In a preferred embodiment, the hollow tubular support element has an outer diameter less than 7 millimeters.

[0284] The hollow tubular support element may have a wall thickness of at least 1 millimeter, preferably at least 1.5 millimeters, more preferably at least 2 millimeters.

[0285] The hollow tubular support element may have a length of at least 5 millimeters. Preferably, the support element has a length of at least 6 millimeters, more preferably at least about 7 millimeters.

[0286] The hollow tubular support element may have a length less than 15 millimeters. Preferably, the hollow tubular support element has a length less than 12 millimeters, more preferably less than 10 millimeters.

[0287] In some embodiments, the hollow tubular support element has a length of 5 millimeters to 15 millimeters, preferably 6 millimeters to 15 millimeters, more preferably 7 millimeters to 15 millimeters. In other embodiments, the hollow tubular support element has a length of 5 millimeters to 12 millimeters, preferably 6 millimeters to 12 millimeters, more preferably 7 millimeters to 12 millimeters. In further embodiments, the support element has a length of 5 millimeters to 10 millimeters, preferably 6 millimeters to 10 millimeters, more preferably 7 millimeters to 10 millimeters.

[0288] As an alternative to, or in addition to, the hollow tubular support element, the downstream section may further comprise a downstream hollow tubular element downstream of the hollow tubular cooling element. The downstream hollow tubular element may be provided immediately adjacent to the hollow tubular cooling element. Alternatively, and preferably, the downstream hollow tubular element is separated from the hollow tubular cooling element by at least one other component. For example, the downstream section may comprise a downstream filter segment between the hollow tubular cooling element and the downstream hollow tubular element.

[0289] The downstream hollow tubular element preferably extends to the downstream end of the downstream section. Thus, the downstream hollow tubular element preferably extends to the downstream end of the aerosol generating article. When the downstream hollow tubular element extends to the downstream end of the aerosol generating article, the downstream hollow tubular element may define the mouth-side end cavity of the aerosol generating article.

[0290] In certain embodiments, additional downstream hollow tubular elements may be provided such that the downstream section comprises two adjacent downstream hollow tubular elements downstream of the downstream filter segment.

[0291] The RTD of the downstream hollow tubular element may be 10 millimeters H2O or less, or 5 millimeters H2O or less, or 2.5 millimeters H2O or less, or 2 millimeters H2O or less. Preferably, the RTD of the downstream hollow tubular element is 1 millimeter H2O or less.

[0292] The RTD of the downstream hollow tubular element may be at least 0 millimeters H2O, or at least 0.25 millimeters H2O, or at least 0.5 millimeters H2O, or at least 1 millimeter H2O.

[0293] Thus, the flow channel of the downstream hollow tubular element should not include any component that would impede the flow of air in the longitudinal direction. Preferably, the flow channel is substantially empty, and particularly preferably, the flow channel is empty.

[0294] Preferably, the length of the downstream hollow tubular element is at least 3 millimeters, more preferably at least 4 millimeters, more preferably at least 5 millimeters, more preferably at least 6 millimeters.

[0295] Preferably, the length of the downstream hollow tubular element is less than 20 millimeters, more preferably less than 15 millimeters, more preferably less than 12 millimeters, more preferably less than 10 millimeters.

[0296] The lumen or cavity of the downstream hollow tubular element may have any cross-sectional shape. The lumen of the downstream hollow tubular element may have a circular cross-sectional shape.

[0297] The downstream hollow tubular element may include a paper-based material. The downstream hollow tubular element may include at least one layer of paper. The paper can be very hard paper. The paper can be curled paper such as heat-resistant curled paper or curled sulfuric acid paper.

[0298] The downstream hollow tubular element may include cardboard. The downstream hollow tubular element can be a cardboard tube.

[0299] The downstream hollow tubular element can be a paper tube. The downstream hollow tubular element can be a tube formed from spirally wound paper. The downstream hollow tubular element can be formed from a plurality of layers of paper. The paper can have a basis weight of at least 50 grams per square meter, at least 60 grams per square meter, at least 70 grams per square meter, or at least 90 grams per square meter.

[0300] The downstream hollow tubular element may include a polymer material. For example, the downstream hollow tubular element may include a polymer film. The polymer film may include a cellulose film. The downstream hollow tubular element may include low-density polyethylene (LDPE) or polyhydroxyalkanoate (PHA) fibers. The downstream hollow tubular element preferably comprises cellulose acetate tow. For example, in a preferred embodiment, the downstream hollow tubular element includes a hollow acetate tube.

[0301] When the downstream hollow tubular element comprises cellulose acetate tow, the cellulose acetate tow may have 2 to 4 denier per filament and a total denier of 25 to 40.

[0302] When the downstream section further comprises the additional downstream hollow tubular element described above, the additional downstream hollow tubular element may be formed of the same material as, or a different material from, the downstream hollow tubular element.

[0303] In certain preferred embodiments, the downstream section may comprise a ventilation zone at a location on the downstream hollow tubular element. In one example, this ventilation zone at a location on the downstream hollow tubular element may be provided in place of the ventilation zone at a location on the hollow tubular cooling element. In another example, the ventilation zone at a location on the downstream hollow tubular element may be provided in addition to the ventilation zone provided at a location on the hollow tubular cooling element.

[0304] The ventilation zone at a location along the downstream hollow tubular element may include a plurality of perforations through the peripheral wall of the downstream hollow tubular element. Preferably, the ventilation zone at a location along the downstream hollow tubular element includes at least one circumferential row of perforations. In some embodiments, the ventilation zone may include two circumferential rows of perforations. For example, the perforations may be formed online during the manufacture of the aerosol-generating article. Preferably, each circumferential row of perforations includes 8 to 30 perforations.

[0305] The aerosol-generating article according to the present disclosure may further comprise an upstream section located upstream of the aerosol-generating rod. The upstream section is preferably located immediately upstream of the aerosol-generating rod. The upstream section preferably extends between the upstream end of the aerosol-generating article and the aerosol-generating rod. The upstream section may comprise one or more upstream elements located upstream of the aerosol-generating rod.

[0306] The aerosol-generating article of the present invention preferably comprises an upstream element located upstream of and adjacent to the aerosol-generating rod. The upstream element advantageously prevents direct physical contact with the upstream end of the aerosol-generating rod. Furthermore, the presence of the upstream element helps to prevent any loss of the substrate, which may be advantageous, for example, when the substrate contains particulate plant material.

[0307] If the upstream segment of the aerosol-generating rod contains shredded tobacco, such as tobacco cut filler, the upstream section or element may additionally serve to prevent loss of loose particles of tobacco from the upstream end of the article. This can be particularly important, for example, when the density of the shredded tobacco is relatively low.

[0308] The upstream element may be a porous plug element. The upstream element preferably has a porosity of at least 50 percent in the longitudinal direction of the aerosol-generating article. More preferably, the upstream element has a porosity of 50 to 90 percent in the longitudinal direction. The porosity of the upstream element in the longitudinal direction is defined by the ratio of the cross-sectional area of the material forming the upstream element to the internal cross-sectional area of the aerosol-generating article at the position of the upstream element.

[0309] The upstream element may be made of a porous material or may comprise a plurality of openings. This can be achieved, for example, by laser drilling. The plurality of openings are preferably uniformly distributed across the cross-section of the upstream element.

[0310] The porosity or permeability of the upstream element is advantageously designed to provide an aerosol-generating article having a specific overall draw resistance (RTD) that does not substantially affect the filtration provided by other parts of the article.

[0311] The upstream element may be formed from a material that is impermeable to air. In such embodiments, the aerosol-generating article may be configured such that air flows into the aerosol-generating rod via suitable ventilation means provided within the wrapper.

[0312] In certain preferred embodiments of the present invention, it may be desirable to minimize the RTD of the upstream element. For example, this may apply to articles intended to be inserted into the cavity of an aerosol generating device such that the aerosol generating substrate is externally heated, as described herein. In the case of such articles, it is desirable to provide the article with as low an RTD as possible such that most of the RTD experience by the consumer is provided by the aerosol generating device rather than the article.

[0313] The RTD of the upstream element may be less than 30 millimeters H2O, or less than 20 millimeters H2O, or less than 10 millimeters H2O, or less than 5 millimeters H2O, or less than 2 millimeters H2O.

[0314] The RTD of the upstream element may be at least 0.1 millimeter H2O, or at least 0.25 millimeter H2O, or at least 0.5 millimeter H2O.

[0315] Preferably, the upstream element has an RTD of less than 2 millimeters H2O per millimeter of length, more preferably less than 1.5 millimeters H2O per millimeter of length, more preferably less than 1 millimeter H2O per millimeter of length, more preferably less than 0.5 millimeter H2O per millimeter of length, more preferably less than 0.3 millimeter H2O per millimeter of length, more preferably less than 0.2 millimeter H2O per millimeter of length.

[0316] Preferably, the combined RTD of the upstream section or its upstream element and the aerosol generating rod is less than 15 millimeters H2O, more preferably less than 12 millimeters H2O, more preferably less than 10 millimeters H2O.

[0317] In certain preferred embodiments, the upstream element is formed of a solid cylindrical plug element having a filled cross-section. Such plug elements may be referred to as "plane" elements. The solid plug element may be porous as described above, but does not have a tubular form and thus does not provide a longitudinal flow channel. The solid plug element preferably has a substantially uniform cross-section.

[0318] In other preferred embodiments, the upstream element is formed from a hollow tubular segment that defines a longitudinal cavity providing an unrestricted flow channel. In such embodiments, the upstream element can, as described above, provide protection to the aerosol generating substrate while having a minimal effect on the overall draw resistance (RTD) and filtration properties of the article.

[0319] Preferably, the diameter of the longitudinal cavity of the hollow tubular segment forming the upstream element is at least 3 millimeters, more preferably at least 3.5 millimeters, more preferably at least 4 millimeters, more preferably at least 4.5 millimeters. Preferably, the diameter of the longitudinal cavity is maximized to minimize the RTD of the upstream section or its upstream element.

[0320] Preferably, the wall thickness of the hollow tubular segment is less than 2 millimeters, more preferably less than 1.5 millimeters, and more preferably less than 1 millimeter.

[0321] The upstream element of the upstream section may be made of any material suitable for use in an aerosol generating article. The upstream element may be made of the same material as that used for one of the other components of the aerosol generating article, such as, for example, a downstream filter segment or a hollow tubular cooling element. Suitable materials for forming the upstream element include filter materials, ceramics, polymeric materials, cellulose acetate, cardboard, zeolites, or the aerosol generating substrate. The upstream element may include a plug of cellulose acetate. The upstream element may comprise a hollow acetate tube or a cardboard tube.

[0322] Preferably, the upstream element is formed from a heat-resistant material. For example, preferably, the upstream element is formed from a material that can withstand a temperature of up to 350 degrees Celsius. This ensures that the upstream element is not adversely affected by the heating means for heating the aerosol generating substrate.

[0323] Preferably, the upstream section or its upstream element has an outer diameter that is approximately equal to the outer diameter of the aerosol generating article. Preferably, the outer diameter of the upstream section, or its upstream element, is 5 millimeters to 8 millimeters, more preferably 5.25 millimeters to 7.5 millimeters, and even more preferably 5.5 millimeters to 7 millimeters.

[0324] Preferably, the upstream section or upstream element has a length of 2 millimeters to 10 millimeters, more preferably 3 millimeters to 8 millimeters, and even more preferably 2 millimeters to 6 millimeters. In a particularly preferred embodiment, the upstream section or upstream element has a length of 5 millimeters.

[0325] The upstream section is preferably surrounded by a wrapper such as a plug wrap. The wrapper surrounding the upstream section is preferably a rigid plug wrap, for example, a plug wrap having a basis weight of at least 80 grams per square meter (gsm), or at least 100 gsm, or at least 110 gsm. This provides structural rigidity to the upstream section.

[0326] The upstream section is preferably connected by an outer wrapper to the aerosol generating rod and optionally at least a portion of the downstream section.

[0327] The aerosol generating article according to the present invention may have an overall length of at least 40 millimeters, or at least 50 millimeters, or at least 60 millimeters.

[0328] The overall length of the aerosol generating article according to the present invention may be 90 millimeters or less, or 85 millimeters or less, or 80 millimeters or less.

[0329] In some embodiments, the overall length of the aerosol generating article is preferably from 50 millimeters to 90 millimeters, more preferably from 60 millimeters to 90 millimeters, and even more preferably from 70 millimeters to 90 millimeters. In other embodiments, the overall length of the aerosol generating article is preferably from 50 millimeters to 85 millimeters, more preferably from 60 millimeters to 85 millimeters, and even more preferably from 70 millimeters to 85 millimeters. In further embodiments, the overall length of the aerosol generating article is preferably from 50 millimeters to 80 millimeters, more preferably from 60 millimeters to 80 millimeters, and even more preferably from 70 millimeters to 80 millimeters. In an exemplary embodiment, the overall length of the aerosol generating article is 75 millimeters.

[0330] In some embodiments, the overall length of the aerosol generating article is preferably from 40 millimeters to 70 millimeters, more preferably from 45 millimeters to 70 millimeters. In other embodiments, the overall length of the aerosol generating article is preferably from 40 millimeters to 60 millimeters, more preferably from 45 millimeters to 60 millimeters. In further embodiments, the overall length of the aerosol generating article is preferably from 40 millimeters to 50 millimeters, more preferably from 45 millimeters to 50 millimeters. In an exemplary embodiment, the overall length of the aerosol generating article is about 45 millimeters.

[0331] Preferably, the aerosol generating article has an outer diameter of at least about 5 millimeters. More preferably, the aerosol generating article has an outer diameter of at least 5.25 millimeters. Even more preferably, the aerosol generating article has an outer diameter of at least 5.5 millimeters.

[0332] The aerosol generating article preferably has an outer diameter of 8 millimeters or less. More preferably, the aerosol generating article has an outer diameter of 7.5 millimeters or less. Even more preferably, the aerosol generating article has an outer diameter of 7 millimeters or less.

[0333] The aerosol generating article may have an outer diameter of 5 millimeters to 8 millimeters, or 5 millimeters to 7.5 millimeters, or 5 millimeters to 7 millimeters, or 5.25 millimeters to 8 millimeters, or 5.25 millimeters to 7.5 millimeters, or 5.25 millimeters to 7 millimeters, or 5.5 millimeters to 8 millimeters, or 5.5 millimeters to 7.5 millimeters, or 5.5 millimeters to 7 millimeters.

[0334] The outer diameter of the aerosol generating article may be substantially constant over the entire length of the article. Alternatively, different portions of the aerosol generating article may have different outer diameters.

[0335] Preferably, the overall RTD of the aerosol generating article is at least 10 millimeters H2O. For example, the RTD of the aerosol generating article may be at least 20 millimeters H2O, at least 30 millimeters H2O, at least 35 millimeters H2O, or at least 40 millimeters H2O.

[0336] The overall RTD of the aerosol generating article may be 70 millimeters H2O or less. For example, the overall RTD of the aerosol generating article may be 65 millimeters H2O or less, 60 millimeters H2O or less, or 55 millimeters H2O or less, or 50 millimeters H2O or less.

[0337] The overall RTD of the aerosol-generating article may be from 10 millimeters H2O to 70 millimeters H2O. For example, the overall RTD of the aerosol-generating article may be from 20 millimeters H2O to 65 millimeters H2O, from 30 millimeters H2O to 60 millimeters H2O, from 35 millimeters H2O to about 55 millimeters H2O, or from 40 millimeters H2O to about 50 millimeters H2O.

[0338] In a particularly preferred embodiment, one or more of the components of the aerosol-generating article are individually surrounded by their own wrapper.

[0339] In an embodiment, the aerosol-generating rod and the mouthpiece element are individually wrapped. The upstream element, the aerosol-generating rod, and the hollow tubular element are then combined together with an outer wrapper. Thereafter, they are combined with a downstream filter element having its own wrapper by tipping paper.

[0340] Preferably, at least one of the components of the aerosol-generating article is wrapped with a hydrophobic wrapper.

[0341] The term "hydrophobic" refers to a surface that exhibits water-repellent properties. One useful way to determine this is to measure the water contact angle. The "water contact angle" is an angle conventionally measured through a liquid, where the liquid / vapor interface meets the solid surface. This quantifies the wetting of the solid surface by the liquid via Young's equation. The hydrophobicity or water contact angle may be determined by utilizing the TAPPI T558 test method, and the results are reported as the interfacial contact angle in "degrees" and can range from approximately zero to approximately 180 degrees.

[0342] In a preferred embodiment, the hydrophobic wrapper comprises a paper layer having a water contact angle of about 30 degrees or more, preferably about 35 degrees or more, or about 40 degrees or more, or about 45 degrees or more.

[0343] As an example, the paper layer may contain PVOH (polyvinyl alcohol) or silicon. PVOH may be applied to the paper layer as a surface coating, or the paper layer may include a surface treatment containing PVOH or silicon.

[0344] According to a second aspect of the present invention, there is provided an aerosol generating system comprising an aerosol generating article according to a first aspect of the present invention and an aerosol generating device, the aerosol generating device comprising a heating chamber for receiving at least a part of the aerosol generating article and a heater for heating an aerosol generating rod of the aerosol generating article when the aerosol generating article is received in the heating chamber.

[0345] The aerosol generating device has a distal end and a mouth-side end. The aerosol generating device may comprise a body or a housing. The body or housing of the aerosol generating device may define a device cavity for removably receiving the aerosol generating article at the mouth-side end of the device.

[0346] The device cavity may be referred to as the heating chamber of the aerosol generating device. The device cavity may extend between the distal end and the mouth-side, or the proximal end. The distal end of the device cavity may be a closed end, and the mouth-side or proximal end of the device cavity may be an open end. The aerosol generating article may be inserted into the device cavity or the heating chamber through the open end of the device cavity. The device cavity may be cylindrical so as to conform to the same shape of the aerosol generating article.

[0347] The expression "received therein" may refer to the fact that a component or element is received, either fully or partially, within another component or element. For example, the expression "the aerosol-generating article is received within the device cavity" refers to the fact that the aerosol-generating article is received, either fully or partially, within the device cavity of the aerosol-generating article. When the aerosol-generating article is received within the device cavity, the aerosol-generating article may abut against the distal end of the device cavity. When the aerosol-generating article is received within the device cavity, the aerosol-generating article may be substantially proximate to the distal end of the device cavity. The distal end of the device cavity may be defined by an end wall.

[0348] The length of the device cavity may be 15 millimeters to 80 millimeters, or 20 millimeters to 70 millimeters, or 25 millimeters to 60 millimeters, or 25 millimeters to 50 millimeters.

[0349] The length of the device cavity (or heating chamber) may be the same as the length of the aerosol-generating rod, or may be longer than that. The length of the device cavity may be the same as the combined length of the upstream section or element and the aerosol-generating rod, or may be longer than that. Preferably, the length of the device cavity is such that at least 75 percent of the length of the aerosol-generating rod is inserted or received within the device cavity when the aerosol-generating article is received with the aerosol-generating device. More preferably, the length of the device cavity is such that at least 80 percent of the length of the aerosol-generating rod is inserted or received within the device cavity when the aerosol-generating article is received with the aerosol-generating device. Even more preferably, the length of the device cavity is such that at least 90 percent of the length of the aerosol-generating rod is inserted or received within the device cavity when the aerosol-generating article is received with the aerosol-generating device. This maximizes the length of the aerosol-generating rod that can be heated during use, thereby optimizing the generation of aerosol from the aerosol-generating substrate and reducing tobacco waste.

[0350] The length of the device cavity may be configured such that when the aerosol-generating article is received within the device cavity, a downstream section or a portion thereof protrudes from the device cavity. The length of the device cavity may be such that when the aerosol-generating article is received within the device cavity, a portion of the downstream section (such as a hollow tubular cooling element or a downstream filter segment) protrudes from the device cavity. The length of the device cavity may be such that when the aerosol-generating article is received within the device cavity, a portion of the downstream section (such as a hollow tubular cooling element or a downstream filter segment) is configured to be received within the device cavity.

[0351] At least 25 percent of the length of the downstream section may be inserted or received within the device cavity when the aerosol-generating article is received within the device. At least 30 percent of the length of the downstream section may be inserted or received within the device cavity when the aerosol-generating article is received within the device.

[0352] The diameter of the device cavity may be from 4 millimeters to 10 millimeters. The diameter of the device cavity may be from 5 millimeters to 9 millimeters. The diameter of the device cavity may be from 6 millimeters to 8 millimeters. The diameter of the device cavity may be from 6 millimeters to 7 millimeters.

[0353] The diameter of the device cavity may be substantially the same as or larger than the diameter of the aerosol-generating article. The diameter of the device cavity may be the same as the diameter of the aerosol-generating article to establish a tight fit therewith.

[0354] The device cavity can be configured to establish a tight fit with an aerosol-generating article received within the device cavity. A tight fit can refer to a slip fit. The aerosol-generating device can comprise a peripheral wall. Such a peripheral wall can define the device cavity or a heating chamber. The peripheral wall defining the device cavity can be configured to engage in a tight fit with an aerosol-generating article received within the device cavity such that there is substantially no gap or empty space between the peripheral wall defining the device cavity and the aerosol-generating article when received within the device.

[0355] Such an airtight fit can establish an airtight fit or configuration between the device cavity and an aerosol-generating article received therein.

[0356] In such an airtight configuration, there will be substantially no gap or empty space between the peripheral wall defining the device cavity and the aerosol-generating article through which air can pass and flow.

[0357] The 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.

[0358] The aerosol-generating device may comprise an airflow channeling extending between a channel inlet and a channel outlet. The airflow channel can be configured to establish fluid communication between the interior of the device cavity and the exterior of the aerosol-generating device. The airflow channel of the aerosol-generating device can be defined within the housing of the aerosol-generating device to enable fluid communication between the interior of the device cavity and the exterior of the aerosol-generating device. When an aerosol-generating article is received within the device cavity, the airflow channel can be configured to provide air flowing into the article to deliver the generated aerosol to a user who aspirates from the mouth-side end of the article.

[0359] 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, or by the inner surface of the peripheral wall, or by a combination of both. The airflow channel may be partially defined by the inner surface of the peripheral wall and may be partially defined within the thickness of the peripheral wall. The inner surface of the peripheral wall defines the periphery of the device cavity.

[0360] The airflow channel of the aerosol generator may extend from an inlet located at the mouth side end or proximal end of the aerosol generator to an outlet located away from the mouth side end of the device. The airflow channel may extend along a direction parallel to the longitudinal axis of the aerosol generator.

[0361] The heater may be of any suitable type. Preferably, in the present invention, the heater is an external heater.

[0362] The heater is located around or surrounding the heating chamber.

[0363] Preferably, the heater externally heats the aerosol generating rod when the aerosol article is received within the aerosol generator. Preferably, the heater externally heats one or both of the first aerosol generating segment and the second aerosol generating segment. Such an external heater may surround the aerosol article when inserted or received within the aerosol generator.

[0364] In some embodiments, the heater is arranged to heat the outer surface of the aerosol generating rod.

[0365] In some embodiments, the heater is arranged for insertion into the aerosol generating substrate when the aerosol generating substrate is received within the cavity.

[0366] The heater may be positioned within the device cavity or the heating chamber.

[0367] 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 a plurality of heating elements.

[0368] Suitable materials for forming at least one resistive heating element include, but are not limited to, semiconductors such as doped ceramics, "conductive" ceramics (e.g., molybdenum disilicide, etc.), carbon, graphite, metals, metal alloys, and composite materials made of ceramic materials and metal materials. Such composite materials may include doped ceramics or undoped ceramics. Examples of suitable doped ceramics include doped silicon carbide. Examples of suitable metals include titanium, zirconium, tantalum, and platinum group metals. Examples of suitable metal alloys include stainless steel, nickel-containing, cobalt-containing, chromium-containing, aluminum-containing, titanium-containing, zirconium-containing, hafnium-containing, niobium-containing, molybdenum-containing, tantalum-containing, tungsten-containing, tin-containing, gallium-containing, manganese-containing, and iron-containing alloys, as well as nickel, iron, cobalt, stainless steel-based superalloys, Timetal (registered trademark), and iron-manganese-aluminum-based alloys.

[0369] In some embodiments, the at least one resistive heating element includes one or more stamped portions of an electrically resistive material such as stainless steel. Alternatively, the at least one resistive heating element may include a heating wire or filament, e.g., a wire of Ni-Cr (nickel-chromium), platinum, tungsten or alloy.

[0370] In some embodiments, the at least one heating element includes an electrically insulated substrate, and the at least one resistive heating element is provided on the electrically insulated substrate.

[0371] The electrically insulated substrate can include any suitable material. For example, the electrically insulated substrate can include one or more of paper, glass, ceramic, anodized metal, coated metal, and polyimide. The ceramic can 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.

[0372] The heater may comprise a heating element including a rigid electrically insulated substrate having one or more conductive tracks or wires disposed on its surface. Depending on the size and shape of the electrically insulated substrate, it may be permissible to insert the heater directly into the aerosol generating substrate. If the electrically insulated substrate is not sufficiently rigid, the heating element may include further reinforcement means. The current may pass through one or more conductive tracks to heat the heating element and the aerosol generating substrate.

[0373] In some embodiments, the heater comprises an induction heating arrangement. The induction heating device can comprise an inductor coil and a power supply configured to provide a high-frequency oscillating current to the inductor coil. As used herein, a high-frequency oscillating current means an oscillating current having a frequency of about 500 kHz to about 30 MHz. The heater can advantageously comprise a DC / AC inverter for converting a DC current supplied by a DC power supply into an alternating current. The inductor coil can be arranged to generate a high-frequency oscillating electromagnetic field when receiving the high-frequency oscillating current from the power supply. The inductor coil can be arranged to generate a high-frequency oscillating electromagnetic field within the device cavity. In some embodiments, the inductor coil can substantially surround the device cavity. The inductor coil can extend at least partially along the length of the device cavity.

[0374] The heater may include an induction heating element. The induction heating element may be a susceptor element. The susceptor element may be arranged such that when the aerosol generating article is received within the cavity of the aerosol generating device, an oscillating electromagnetic field generated by an inductor coil induces a current within the susceptor element and heats the susceptor element. In these embodiments, the aerosol generating device preferably has the ability to generate a varying electromagnetic field having a magnetic field strength (strength of the H field) of from 1 to 5 kiloamperes per meter (kA / m), preferably from 2 to 3 kA / m, for example about 2.5 kA / m. An electrically operating aerosol generating device preferably has the ability to generate a varying electromagnetic field having a frequency of from 1 to 30 megahertz (MHz), for example from 1 to 10 MHz, for example from 5 to 7 MHz.

[0375] In these embodiments, the susceptor element is preferably positioned in contact with the aerosol generating substrate. In some embodiments, the susceptor element is located within the aerosol generating device. In these embodiments, the susceptor element may be located within the cavity. The aerosol generating device may include only one susceptor element. The aerosol generating device may comprise a plurality of susceptor elements. In some embodiments, the susceptor element is preferably arranged to heat the outer surface of the aerosol generating substrate.

[0376] The susceptor element may comprise any suitable material as described above in relation to the susceptor element incorporated within the aerosol generating rod.

[0377] 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.

[0378] In use, the heater can be controlled to operate within a defined operating temperature range below the maximum operating temperature. The operating temperature range within the heating chamber (or device cavity) is preferably from about 150 degrees Celsius to about 300 degrees Celsius. The operating temperature range of the heater may be from about 150 degrees Celsius to about 250 degrees Celsius.

[0379] The aerosol generating device may be provided with a power source. The power source may be a DC power source. In some embodiments, the power source is a battery. The power source may be a nickel-metal hydride battery, a nickel-cadmium battery, or a lithium-based battery such as a lithium cobalt battery, a lithium iron phosphate battery, or a lithium polymer battery. However, in some embodiments, the power source may be another form of charge storage device such as a capacitor. The power source may be required to be rechargeable and may have a capacity that allows sufficient energy storage for one or more user operations such as one or more experiences of aerosol generation.

[0380] Non-limiting examples are provided below in a non-exhaustive manner. Any one or more of the features of these examples may be combined with any one or more of the features of another example, embodiment, or aspect described herein.

[0381] Example 1. An aerosol generating article comprising an aerosol generating rod for generating an inhalable aerosol upon heating, the aerosol generating rod comprising a first aerosol generating segment comprising a first aerosol generating substrate and a second aerosol generating segment comprising a second aerosol generating substrate.

[0382] Example 2. The aerosol generating article according to Example 1, wherein the second aerosol generating segment is located upstream of the first aerosol generating segment.

[0383] Example 3. The aerosol generating article according to Example 1 or Example 2, wherein the first aerosol generating substrate and the second aerosol generating substrate are aligned in an end-to-end contact relationship.

[0384] Example 4. The aerosol generating article according to any one of Examples 1 to 3, wherein the aerosol generating article has a ventilation level of at least 40 percent.

[0385] Example 5. An aerosol generating article according to any one of Examples 1 to 4, wherein the total combined length of the first aerosol generating segment and the second aerosol generating segment is at least 20 millimeters.

[0386] Example 6. An aerosol generating article according to any one of Examples 1 to 5, wherein the total combined length of the first aerosol generating segment and the second aerosol generating segment is less than 50 millimeters.

[0387] Example 7. An aerosol generating article according to any one of Examples 1 to 6, wherein the length of the second aerosol generating segment is within 2 millimeters of the length of the first aerosol generating segment.

[0388] Example 8. An aerosol generating article according to any one of Examples 1 to 7, wherein the length of the second aerosol generating segment is within 10 percent of the length of the first aerosol generating segment.

[0389] Example 9. An aerosol generating article according to any one of Examples 1 to 8, wherein the length of the second aerosol generating segment is approximately equal to the length of the first aerosol generating segment.

[0390] Example 10. An aerosol generating article according to any one of Examples 1 to 8, wherein the length of the second aerosol generating segment is greater than the length of the first aerosol generating segment.

[0391] Example 11. An aerosol generating article according to any one of Examples 1 to 6 and Example 10, wherein the length of the second aerosol generating segment is at least 3 millimeters greater than the length of the first aerosol generating segment.

[0392] Example 12. An aerosol generating article according to any one of Examples 1 to 6 and Example 10 or Example 11, wherein the ratio of the length of the first aerosol generating segment to the length of the second aerosol generating segment is 1 or less.

[0393] Example 13. An aerosol generating article according to any one of Examples 1 to 8, wherein the length of the first aerosol generating segment is greater than the length of the second aerosol generating segment.

[0394] Example 14. An aerosol generating article according to any one of Examples 1 to 6 and Example 13, wherein the length of the first aerosol generating segment is at least 3 millimeters greater than the length of the second aerosol generating segment.

[0395] Example 15. An aerosol generating article according to any one of Examples 1 to 6, Example 13 or Example 14, wherein the ratio of the length of the second aerosol generating segment to the length of the first aerosol generating segment is 1 or less.

[0396] Example 16. An aerosol generating article according to any one of Examples 1 to 15, wherein the first aerosol generating segment has a length of at least 10 millimeters.

[0397] Example 17. An aerosol generating article according to any one of Examples 1 to 16, wherein the first aerosol generating segment has a length of 25 millimeters or less.

[0398] Example 18. An aerosol generating article according to any one of Examples 1 to 17, wherein the second aerosol generating segment has a length of at least 10 millimeters.

[0399] Example 19. An aerosol generating article according to any one of Examples 1 to 18, wherein the second aerosol generating segment has a length of 25 millimeters or less.

[0400] Example 20. An aerosol generating article according to any one of Examples 1 to 19, wherein the aerosol generating rod has a length of at least about 20 millimeters.

[0401] Example 21. An aerosol-generating article according to any one of Examples 1 to 20, wherein the aerosol-generating rod has a length of 50 millimeters or less.

[0402] Example 22. An aerosol-generating article according to any one of Examples 1 to 21, wherein the ratio of the total combined length of the first aerosol-generating segment and the second aerosol-generating segment to the overall length of the aerosol-generating article is at least 0.20.

[0403] Example 23. An aerosol-generating article according to any one of Examples 1 to 22, wherein the ratio of the total combined length of the first aerosol-generating segment and the second aerosol-generating segment to the overall length of the aerosol-generating article is 0.60 or less.

[0404] Example 24. An aerosol-generating article according to any one of Examples 1 to 23, wherein the ratio of the length of the first aerosol-generating segment to the overall length of the aerosol-generating article is at least 0.10.

[0405] Example 25. An aerosol-generating article according to any one of Examples 1 to 24, wherein the ratio of the length of the first aerosol-generating segment to the overall length of the aerosol-generating article is 0.30 or less.

[0406] Example 26. An aerosol-generating article according to any one of Examples 1 to 25, wherein the ratio of the length of the second aerosol-generating segment to the overall length of the aerosol-generating article is at least 0.10.

[0407] Example 27. An aerosol-generating article according to any one of Examples 1 to 26, wherein the ratio of the length of the first aerosol-generating segment to the overall length of the aerosol-generating article is 0.30 or less.

[0408] Example 28. An aerosol-generating article according to any one of Examples 1 to 27, wherein the ratio of the length of the aerosol-generating rod to the overall length of the aerosol-generating article is at least 0.20.

[0409] Example 29. An aerosol-generating article according to any one of Examples 1 to 28, wherein the ratio of the length of the aerosol-generating rod to the total length of the aerosol-generating article is 0.6 or less.

[0410] Example 30. An aerosol-generating article according to any one of Examples 1 to 29, wherein the density of the second aerosol-generating substrate is within 50 mg per cubic centimeter of the density of the first aerosol-generating substrate.

[0411] Example 31. An aerosol-generating article according to any one of Examples 1 to 30, wherein the density of the second aerosol-generating substrate is within 10% of the density of the first aerosol-generating substrate.

[0412] Example 32. An aerosol-generating article according to any one of Examples 1 to 31, wherein the density of the second aerosol-generating substrate is substantially equal to the density of the first aerosol-generating substrate.

[0413] Example 33. An aerosol-generating article according to any one of Examples 1 to 31, wherein the density of the second aerosol-generating substrate is greater than the density of the first aerosol-generating substrate.

[0414] Example 34. An aerosol-generating article according to any one of Examples 1 to 28 and Example 33, wherein the density of the second aerosol-generating substrate is at least 100 mg per cubic centimeter higher than the density of the first aerosol-generating substrate.

[0415] Example 35. An aerosol-generating article according to any one of Examples 1 to 28 and Example 33 or Example 34, wherein the density of the second aerosol-generating substrate is at least 1.2 times the density of the first aerosol-generating substrate.

[0416] Example 36. An aerosol-generating article according to any one of Examples 1 to 31, wherein the density of the first aerosol-generating substrate is greater than the density of the second aerosol-generating substrate.

[0417] Example 37. An aerosol generating article according to any one of Examples 1 to 28 and Example 36, wherein the density of the first aerosol generating substrate is at least 100 mg per cubic centimeter higher than the density of the second aerosol generating substrate.

[0418] Example 38. An aerosol generating article according to any one of Examples 1 to 28, Example 36 or Example 37, wherein the density of the first aerosol generating substrate is at least 1.2 times the density of the second aerosol generating substrate.

[0419] Example 39. An aerosol generating article according to any one of Examples 1 to 38, wherein the density of the first aerosol generating substrate is at least 100 mg per cubic centimeter.

[0420] Example 40. An aerosol generating article according to any one of Examples 1 to 39, wherein the density of the first aerosol generating substrate is 500 mg or less per cubic centimeter.

[0421] Example 41. An aerosol generating article according to any one of Examples 1 to 40, wherein the density of the second aerosol generating substrate is at least 100 mg per cubic centimeter.

[0422] Example 42. An aerosol generating article according to any one of Examples 1 to 41, wherein the density of the second aerosol generating substrate is 500 mg or less per cubic centimeter.

[0423] Example 43. An aerosol generating article according to any one of Examples 1 to 42, wherein the first aerosol generating substrate has substantially the same composition as the second aerosol generating substrate.

[0424] Example 44. An aerosol generating article according to any one of Examples 1 to 43, wherein the first aerosol generating substrate contains one or more aerosol formers.

[0425] Example 45. An aerosol generating article according to any one of Examples 1 to 44, wherein the second aerosol generating substrate contains one or more aerosol formers.

[0426] Example 46. An aerosol generating article according to any one of Examples 1 to 45, wherein the aerosol former content of the second aerosol generating substrate is within 3 percentage points of the aerosol former content of the first aerosol generating substrate.

[0427] Example 47. An aerosol generating article according to any one of Examples 1 to 46, wherein the aerosol former content of the second aerosol generating substrate is within 10% of the aerosol former content of the first aerosol generating substrate.

[0428] Example 48. An aerosol generating article according to any one of Examples 1 to 47, wherein the aerosol former content of the first aerosol generating substrate is approximately equal to the aerosol former content of the second aerosol generating substrate.

[0429] Example 49. An aerosol generating article according to any one of Examples 1 to 47, wherein the aerosol former content of the second aerosol generating substrate is greater than the aerosol former content of the first aerosol generating substrate on a dry weight basis.

[0430] Example 50. An aerosol generating article according to any one of Examples 1 to 45 and Example 49, wherein the aerosol former content of the second aerosol generating substrate is at least 15 percentage points higher than the aerosol former content of the first aerosol generating substrate.

[0431] Example 51. An aerosol generating article according to any one of Examples 1 to 45 and Example 49 or Example 50, wherein the aerosol former content of the second aerosol generating substrate is at least 1.2 times that of the first aerosol generating substrate.

[0432] Example 52. An aerosol generating article according to any one of Examples 1 to 47, wherein the aerosol former content of the first aerosol generating substrate is greater than the aerosol former content of the second aerosol generating substrate on a dry weight basis.

[0433] Example 53. An aerosol generating article according to any one of Examples 1 to 47 and Example 52, wherein the aerosol former content of the first aerosol generating substrate is at least 15 percentage points higher than the aerosol former content of the second aerosol generating substrate.

[0434] Example 54. An aerosol generating article according to any one of Examples 1 to 47 and Example 52 or 53, wherein the aerosol former content of the first aerosol generating substrate is at least 1.2 times the aerosol former content of the second aerosol generating substrate.

[0435] Example 55. An aerosol generating article according to any one of Examples 1 to 54, wherein the first aerosol generating substrate contains at least 5% by weight of aerosol former on a dry weight basis.

[0436] Example 56. An aerosol generating article according to any one of Examples 1 to 55, wherein the first aerosol generating substrate contains 80% by weight or less of aerosol former on a dry weight basis.

[0437] Example 57. An aerosol generating article according to any one of Examples 1 to 56, wherein the second aerosol generating substrate contains at least 5% by weight of aerosol former on a dry weight basis.

[0438] Example 58. An aerosol generating article according to any one of Examples 1 to 57, wherein the second aerosol generating substrate contains 80% by weight or less of aerosol former on a dry weight basis.

[0439] Example 59. An aerosol generating article according to any one of Examples 1 to 58, wherein one or both of the first aerosol generating substrate and the second aerosol generating substrate contain shredded tobacco material.

[0440] Example 60. An aerosol generating article according to any one of Examples 1 to 59, wherein one or both of the first aerosol generating substrate and the second aerosol generating substrate are provided with a tobacco cut filter.

[0441] Example 61. An aerosol generating article according to any one of Examples 1 to 60, wherein one or both of the first aerosol generating substrate and the second aerosol generating substrate are provided with a shredded sheet of homogenized tobacco material.

[0442] Example 62. An aerosol generating article according to any one of Examples 1 to 61, wherein one or both of the first aerosol generating substrate and the second aerosol generating substrate are formed from the same type of material.

[0443] Example 63. An aerosol generating article according to any one of Examples 1 to 62, further comprising one or more elongated susceptor elements within the aerosol generating rod.

[0444] Example 64. An aerosol generating article according to any one of Examples 1 to 65, wherein the first aerosol generating substrate is surrounded by a first wrapper and the second aerosol generating substrate is surrounded by a second wrapper separate from the first wrapper.

[0445] Example 65. An aerosol generating article according to any one of Examples 1 to 64, further comprising a downstream section located downstream of the aerosol generating rod.

[0446] Example 66. An aerosol generating article according to Example 65, wherein the downstream section extends to the downstream end of the aerosol generating article.

[0447] Example 67. An aerosol-generating article according to Example 65 or Example 66, wherein the downstream section comprises a hollow tubular cooling element.

[0448] Example 68. An aerosol-generating article according to Example 67, wherein the hollow tubular cooling element has a length of at least 15 millimeters.

[0449] Example 69. An aerosol-generating article according to any one of Examples 65 to 68, wherein the downstream section comprises a ventilation zone.

[0450] Example 70. An aerosol-generating article according to any one of Examples 67 to 69, wherein the ventilation zone is located along the hollow tubular cooling element.

[0451] Example 71. An aerosol-generating article according to any one of Examples 1 to 70, wherein the aerosol-generating article has a ventilation level of 90 percent or less.

[0452] Example 72. An aerosol-generating article according to any one of Examples 66 to 71, wherein the downstream section comprises a downstream filter segment.

[0453] Example 73. An aerosol-generating article according to Example 72, wherein the downstream filter segment is a solid plug.

[0454] Example 74. An aerosol-generating article according to Example 72 or Example 73, wherein the downstream filter segment has a length of at least 5 millimeters.

[0455] Example 75. An aerosol-generating article according to any one of Examples 66 to 74, wherein the downstream section further comprises a hollow tubular support element upstream of the hollow tubular cooling element.

[0456] Example 76. An aerosol-generating article according to any one of Examples 66 to 75, wherein the aerosol-generating article comprises a mouth-side end cavity.

[0457] Example 76. An aerosol generating article according to any one of Examples 66 to 75, wherein the downstream section further comprises a downstream hollow tubular element downstream of the hollow tubular cooling element.

[0458] Example 77. An aerosol generating article according to any one of Examples 1 to 76, further comprising an upstream element provided upstream of the aerosol generating rod.

[0459] Example 78. An aerosol generating article according to any one of Examples 1 to 77, wherein the aerosol generating article has an overall length of 70 millimeters to 80 millimeters.

[0460] Example 79. An aerosol generating article according to any one of Examples 1 to 77, wherein the aerosol generating article has an overall length of 40 millimeters to 50 millimeters.

[0461] Example 80. An aerosol generating system comprising an aerosol generating article according to any one of Examples 1 to 79 and an aerosol generating device, the aerosol generating device comprising a heating chamber for receiving at least a portion of the aerosol generating article and a heater for heating the aerosol generating rod of the aerosol generating article when the aerosol generating article is received within the heating chamber.

[0462] Hereinafter, the present invention will be further described with reference to the drawings of the accompanying drawings.

[0463] The aerosol generating article 10 shown in FIG. 1 comprises an aerosol generating rod 12 and a downstream section 14 located at a location downstream of the rod 12. Accordingly, the aerosol generating article 10 extends from an upstream or distal end 16 that substantially coincides with the upstream end of the rod 12 to a downstream or mouth-side end 18 that coincides with the downstream end of the downstream section 14. The downstream section 14 comprises a hollow tubular cooling element 20, a downstream filter segment 50, and a downstream hollow tubular element 260.

[0464] The aerosol generating article 10 has an overall length of about 75 millimeters and an outer diameter of about 6.7 mm.

[0465] The aerosol generating rod 12 comprises a first aerosol generating segment 24 and a second aerosol generating segment 26 which are coaxially aligned with each other. The second aerosol generating article 26 is provided upstream of the first aerosol generating segment 24 and abuts against the upstream end of the first aerosol generating segment 24.

[0466] The first aerosol generating segment 24 comprises a first aerosol generating substrate formed of shredded tobacco material having a length of about 17 millimeters and containing about 15 weight percent glycerol. The density of the first aerosol generating substrate 24 is about 290 mg per cubic centimeter. The first aerosol generating segment 24 is individually wrapped by a plug wrap (not shown).

[0467] The second aerosol generating segment 26 has substantially the same dimensions and composition as the first aerosol generating segment 24. The second aerosol generating segment 26 comprises a second aerosol generating substrate formed of shredded tobacco material having a length of about 17 millimeters and containing about 15 weight percent glycerol. The density of the second aerosol generating substrate 26 is about 290 mg per cubic centimeter. The second aerosol generating segment 26 is individually wrapped by a plug wrap (not shown).

[0468] The overall length of the aerosol generating rod 12 is about 34 millimeters. The overall length of the downstream section 14 is about 41 millimeters.

[0469] The hollow tubular cooling element 20 of the downstream section 14 is located immediately downstream of the aerosol generating rod 12, and the hollow tubular cooling element 20 is axially aligned with the rod 12. The upstream end of the hollow tubular cooling element 20 abuts against the downstream end of the rod 12.

[0470] The hollow tubular cooling element 20 defines a hollow section of the aerosol generating article 10. The hollow tubular cooling element 20 does not substantially contribute to the overall RTD of the aerosol generating article. More specifically, the RTD of the hollow tubular cooling element 20 is about 0 mmH2O.

[0471] As shown in FIG. 2, the hollow tubular cooling element 20 is provided in the form of a hollow cylindrical tube made of cardboard. The hollow tubular cooling element 20 defines an internal cavity 22 that extends throughout from the upstream end of the hollow tubular cooling element 20 to the downstream end of the hollow tubular cooling element 20. The internal cavity 22 is substantially empty, and thus an airflow with substantially no restriction is enabled along the internal cavity 22.

[0472] The hollow tubular cooling element 20 has a length of about 25 millimeters and an outer diameter of about 6.7 millimeters.

[0473] The aerosol generating article 10 includes a ventilation zone 30 provided at a location along the hollow tubular cooling element 20. The ventilation zone 30 includes a circumferential opening or a row of perforations surrounding the hollow tubular cooling element 20. The perforations of the ventilation zone 30 extend through the wall of the hollow tubular cooling element 20 to allow the intrusion of fluid from the outside of the article 10 into the internal cavity 22. The ventilation level of the aerosol generating article 10 is about 75 percent.

[0474] The downstream filter segment 50 is located immediately downstream of the hollow tubular cooling element 20, and the downstream filter segment 50 is aligned with the hollow tubular cooling element 20 in the longitudinal axis direction. The upstream end of the downstream filter segment 50 abuts against the downstream end of the hollow tubular cooling element 20.

[0475] The downstream filter segment 50 includes a cylindrical plug of cellulose acetate tow. The length of the downstream filter segment 50 is about 10 millimeters.

[0476] The downstream hollow tubular element 60 is provided in the form of a hollow cylindrical tube made of cellulose acetate. The downstream hollow tubular element 60 defines an internal cavity that extends entirely from the upstream end of the downstream hollow tubular cooling element 20 to the downstream end of the downstream hollow tubular element 60 and thus to the downstream end of the aerosol generating article 10. The internal cavity of the downstream hollow tubular element 60 may also be referred to as the mouth-side end cavity. The internal cavity is substantially empty, and thus an airflow with substantially no restrictions is possible along the internal cavity. The downstream hollow tubular element 260 does not substantially contribute to the overall RTD of the aerosol generating article 10. The length of the downstream hollow tubular element 60 is about 6 millimeters.

[0477] As shown in FIGS. 1 and 2, the article 10 includes an upstream wrapper 44 that surrounds the aerosol generating rod 12 and the hollow tubular cooling element 20. The ventilation zone 30 may also include a circumferential row of perforations provided on the upstream wrapper 44. The perforations of the upstream wrapper 44 overlap the perforations provided on the hollow tubular cooling element 20. As a result, the upstream wrapper 44 is located above the perforations of the ventilation zone 30 provided on the hollow tubular cooling element 20.

[0478] The article 10 also includes a tipping wrapper 52 that surrounds the hollow tubular cooling element 20, the mouthpiece element 50, and the downstream hollow tubular element 60. The tipping wrapper 52 is located above a portion of the upstream wrapper 44 that is located above the hollow tubular cooling element 20. Thus, the tipping wrapper 52 effectively couples the mouthpiece element 50 and the downstream hollow tubular element 60 to the remaining components of the article 10. Additionally, the ventilation zone 30 may include a circumferential row of perforations provided on the tipping wrapper 52. The perforations of the tipping wrapper 52 may overlap the perforations provided on the hollow tubular cooling element 20 and on the upstream wrapper 44. As a result, the tipping wrapper 52 may be located above the perforations of the ventilation zone 30 provided on the hollow tubular cooling element 20 and on the upstream wrapper 44.

[0479] FIG. 3 shows an aerosol generating system 100 that includes an exemplary aerosol generating device 1 and the aerosol generating article 10 shown in FIGS. 1 and 2.

[0480] Figure 3 illustrates the mouth-side end portion downstream of the aerosol generator 1 where a device cavity is defined and the aerosol-generating article 10 can be received. The aerosol generator 1 includes a housing (or body) 4 that extends between a mouth-side end 2 and a distal end (not shown). The housing 4 includes a peripheral wall 6. The peripheral wall 6 defines a device cavity for receiving the aerosol-generating article 10. The device cavity is defined by a closed distal end and an open mouth-side end. The mouth-side end of the device cavity is located at the mouth-side end of the aerosol generator 1. The aerosol-generating article 10 is configured to be received through the mouth-side end of the device cavity and to abut against the closed end of the device cavity.

[0481] An air flow channel 5 of the device is defined within the peripheral wall 6. The air flow channel 5 extends between an inlet 7 located at the mouth-side end of the aerosol generator 1 and the closed end of the device cavity. Air may enter the aerosol-generating rod 12 of the aerosol-generating substrate 10 through an opening (not shown) provided at the closed end of the device cavity to ensure fluid communication between the air flow channel 5 and the aerosol-generating rod 12.

[0482] The aerosol generator 1 further includes a heater (not shown) and a power source (not shown) for supplying power to the heater. A controller (not shown) is also provided to control the supply of such power to the heater. The heater is configured to controllably heat the aerosol-generating article 10 during use when the aerosol-generating article 1 is received within the device 1. The heater is preferably arranged to externally heat the aerosol-generating rod 12 for optimal aerosol generation. The ventilation zone 30 is arranged to be exposed when the aerosol-generating article 10 is received within the aerosol generator 1.

[0483] In the embodiment shown in FIG. 3, the device cavity defined by the peripheral wall 6 has a length of 40 millimeters. When the article 10 is received within the device cavity, the aerosol generating rod 12 and the upstream portion of the hollow tubular cooling element 20 are received within the device cavity. Such an upstream portion of the hollow tubular cooling element 20 has a length of 6 millimeters. As a result, approximately 40 millimeters of the article 10 is received within the device 1, and approximately 35 millimeters of the article 10 is located outside of the device 1. In other words, approximately 35 millimeters of the article 10 protrudes from the device 1 when the article 10 is received therein. Such a length of the article 10 protruding from the device 1 is shown in FIG. 3.

[0484] FIG. 4 shows a second embodiment of the first aspect of the present invention. The aerosol generating article 110 shown in FIG. 4 has a structure similar to the aerosol generating article 10 shown in FIGS. 1 and 2, and only differs in the lengths of the second aerosol generating substrate 126 and the first aerosol generating substrate 124.

[0485] The second aerosol generating substrate 126 is longer than the first aerosol generating substrate 124. The second aerosol generating substrate 126 has a length of approximately 22 millimeters, and the first aerosol generating substrate has a length of approximately 12 millimeters. The total length of the aerosol generating rod 112 of the aerosol generating article 110 shown in FIG. 4 is the same as the total length of the aerosol generating rod 12 of the aerosol generating article 10 shown in FIGS. 1 and 2.

[0486] FIG. 5 shows a third embodiment of the first aspect of the present invention. The aerosol generating article 210 shown in FIG. 5 includes an aerosol generating rod 212, a downstream section 214 at a location downstream of the aerosol generating rod 212, and an upstream section 215 at a location upstream of the aerosol generating rod 212. Accordingly, the aerosol generating article 210 extends from an upstream or distal end 216 that substantially coincides with the upstream end of the upstream section 215 to a downstream or mouth-side end 218 that coincides with the downstream end of the downstream section 214. The downstream section 214 includes a hollow tubular cooling element 220 and a downstream filter segment 250.

[0487] The aerosol generating article 210 has an overall length of about 45 millimeters and an outer diameter of about 7.2 mm.

[0488] The aerosol generating rod 212 comprises a first aerosol generating segment 224 and a second aerosol generating segment 226 which are coaxially aligned with each other. The second aerosol generating article 226 is provided upstream of the first aerosol generating segment 224 and abuts against the upstream end of the first aerosol generating segment 224.

[0489] The first aerosol generating segment 224 has a length of about 10 millimeters and comprises a first aerosol generating substrate formed of shredded tobacco material containing 10 wt% to 20 wt% glycerol. The density of the first aerosol generating substrate 224 is about 300 mg per cubic centimeter. The first aerosol generating segment 224 is individually wrapped by a plug wrap (not shown).

[0490] The second aerosol generating segment 226 has substantially the same dimensions and composition as the first aerosol generating segment 224. The second aerosol generating segment 226 has a length of about 10 millimeters and comprises a second aerosol generating substrate formed of shredded tobacco material containing 10 wt% to 20 wt% glycerol. The density of the second aerosol generating substrate 226 is about 300 mg per cubic centimeter. The second aerosol generating segment 226 is individually wrapped by a plug wrap (not shown).

[0491] The overall length of the aerosol generating rod 212 is about 20 millimeters. The overall length of the downstream section 214 is about 20 millimeters. The overall length of the upstream section 215 may be about 5 millimeters.

[0492] The hollow tubular cooling element 220 of the downstream section 14 is located immediately downstream of the aerosol generating rod 12, and the hollow tubular cooling element 220 is aligned axially with the rod 212. The upstream end of the hollow tubular cooling element 20 abuts against the downstream end of the rod 212.

[0493] The hollow tubular cooling element 220 defines the hollow section of the aerosol generating article 210. The hollow tubular cooling element 220 does not substantially contribute to the overall RTD of the aerosol generating article. More specifically, the RTD of the hollow tubular cooling element 220 is approximately 0 mmHg2O.

[0494] As shown in FIG. 5, the hollow tubular cooling element 220 is provided in the form of a hollow cylindrical tube made of cardboard. The hollow tubular cooling element 220 defines an internal cavity 222 that extends entirely from the upstream end of the hollow tubular cooling element 20 to the downstream end of the hollow tubular cooling element 220. The internal cavity 222 is substantially empty, and thus a substantially unrestricted air flow is possible along the internal cavity 222.

[0495] The hollow tubular cooling element 220 has a length of about 13 millimeters, an outer diameter of about 7.2 millimeters, and an inner diameter of about 6.7 millimeters. Therefore, the thickness of the peripheral wall of the hollow tubular element 220 is about 0.25 millimeters.

[0496] The aerosol generating article 210 includes a ventilation zone 230 provided at a location along the hollow tubular cooling element 220. The ventilation zone 230 includes a circumferential opening or row of perforations surrounding the hollow tubular cooling element 220. The perforations of the ventilation zone 230 extend through the wall of the hollow tubular cooling element 220 to allow the intrusion of fluid from the outside of the article 210 into the internal cavity 222. The ventilation level of the aerosol generating article 210 is about 40 percent.

[0497] The downstream filter segment 250 is located immediately downstream of the hollow tubular cooling element 220, and the downstream filter segment 250 is aligned with the hollow tubular cooling element 220 in the longitudinal axis direction. The upstream end of the downstream filter segment 250 abuts against the downstream end of the hollow tubular cooling element 20. The downstream end 218 of the aerosol generating article 210 coincides with the downstream end of the downstream filter segment 250.

[0498] The downstream filter segment 250 comprises a cylindrical plug of cellulose acetate tow. The length of the downstream filter segment 250 is about 7 millimeters.

[0499] The upstream section 215 comprises an upstream element 270 located immediately upstream of the aerosol generating rod 212, and the upstream element 270 is aligned with the rod 212 in the longitudinal axis direction. The downstream end of the upstream element 242 abuts against the upstream end of the aerosol generating rod 212. The upstream end 216 of the aerosol generating article 210 coincides with the upstream end of the upstream element 270. The upstream element 270 may be provided in the form of a cylindrical plug of cellulose acetate tow or in the form of a hollow cylindrical plug of cellulose acetate tow having a wall thickness of about 1 millimeter. The upstream element 270 has a length of about 5 millimeters.

[0500] As shown in FIG. 5, the article 210 comprises an upstream wrapper 244 surrounding the upstream element 270, the aerosol generating rod 212, and the hollow tubular cooling element 220. The ventilation zone 230 may also comprise a circumferential row of perforations provided on the upstream wrapper 244. The perforations of the upstream wrapper 244 overlap the perforations provided on the hollow tubular cooling element 220. As a result, the upstream wrapper 244 is over the perforations of the ventilation zone 230 provided on the hollow tubular cooling element 220.

[0501] The article 210 also includes a tipping wrapper 252 that surrounds the hollow tubular cooling element 220 and the mouthpiece element 250. The tipping wrapper 252 is located on top of a portion of the upstream wrapper 244 that is on top of the hollow tubular cooling element 220. In this way, the tipping wrapper 252 effectively couples the mouthpiece element 250 to the remaining components of the article 210. Additionally, the ventilation zone 230 may include a circumferential row of perforations provided on the tipping wrapper 252. The perforations of the tipping wrapper 252 may overlap the perforations provided on the hollow tubular cooling element 220 and the upstream wrapper 244. As a result, the tipping wrapper 252 may be located on top of the perforations of the ventilation zone 230 provided on the hollow tubular cooling element 220 and the upstream wrapper 44.

[0502] The specific embodiments and examples described above illustrate, but do not limit, the present invention. It is understood that other embodiments of the present invention may be made and that the specific embodiments and examples described herein are not exhaustive.

Claims

1. An aerosol generating article, An aerosol generating rod for generating an aerosol that can be inhaled when heated, A downstream section provided downstream of the aerosol generating rod and extending to the downstream end of the aerosol generating article, A ventilation zone located along the downstream section, The aerosol generating rod, A first aerosol generating segment comprising a first aerosol generating substrate, A second aerosol generating segment is located upstream of the first aerosol generating segment and comprises a second aerosol generating substrate, The combined length of the first aerosol generating segment and the second aerosol generating segment is at least 20 millimeters. The ratio of the combined length of the first aerosol generating segment and the second aerosol generating segment to the total length of the aerosol generating article is 0.6 or less. The aerosol generating article having an air permeability level of at least 40 percent.

2. The aerosol generating article according to claim 1, wherein the first aerosol generating substrate comprises one or more aerosol forming bodies, the second aerosol generating substrate comprises one or more aerosol forming bodies, and the aerosol forming body content of the second aerosol generating substrate is within 10 percent of the aerosol forming body content of the first aerosol generating substrate.

3. The aerosol generating article according to claim 1 or 2, wherein the density of the second aerosol generating substrate is within 10 percent of the density of the first aerosol generating substrate.

4. The aerosol generating article according to claim 1 or 2, wherein the length of the second aerosol generating segment is within 10 percent of the length of the first aerosol generating segment.

5. The aerosol generating article according to claim 1 or 2, wherein the downstream section comprises a hollow tubular cooling element.

6. The aerosol generating article according to claim 5, wherein the ventilation zone comprises a plurality of perforations passing through the peripheral wall of the hollow tubular cooling element.

7. The aerosol generating article according to claim 5, wherein the hollow tubular cooling element has a length of at least 15 millimeters.

8. The aerosol generating article according to claim 5, wherein the downstream section comprises a downstream filter segment located downstream of the hollow tubular cooling element, and the downstream filter segment is a solid plug.

9. The aerosol generating article according to claim 1 or 2, wherein the aerosol generating article has a ventilation level of at least 60 percent.

10. The aerosol generating article according to claim 1 or 2, wherein the aerosol generating article has a total length of at least 60 millimeters.

11. The aerosol generating article according to claim 1 or 2, wherein one or both of the first aerosol generating substrate and the second aerosol generating substrate contain shredded tobacco material.

12. The aerosol generating article according to claim 1 or 2, wherein one or both of the first aerosol generating substrate and the second aerosol generating substrate have a density of less than 400 milligrams per cubic centimeter.

13. The aerosol generating article according to claim 1 or 2, wherein each of the first aerosol generating substrate and the second aerosol generating substrate contains at least 5 weight percent of an aerosol forming body on a dry weight basis.

14. The aerosol generating article according to claim 1 or 2, wherein the first aerosol generating substrate is surrounded by a first wrapper, and the second aerosol generating substrate is surrounded by a second wrapper separate from the first wrapper.

15. Aerosol generation system, The aerosol generating article according to claim 1 or 2 and An aerosol generating system comprising: an aerosol generating device, wherein the aerosol generating device comprises: a heating chamber for receiving at least a portion of the aerosol generating article; and a heater for heating the aerosol generating rod of the aerosol generating article when the aerosol generating article is received in the heating chamber.

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