Aerosol generating product having two aerosol generating segments

Abstract

FIELD: aerosol generating product.SUBSTANCE: aerosol generating product (10, 110, 210) which comprises an aerosol generating rod (12, 112, 212) for producing an inhalable aerosol upon heating, wherein the aerosol-generating rod (12, 112, 212) comprises: a first aerosol-generating segment (24, 124, 224) containing 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 containing a second aerosol-generating substrate, wherein the 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, wherein the 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 the total length of the aerosol-generating article (10, 110, 210) is less than or equal to 0.6, wherein the aerosol-generating article has a ventilation level of at least 40 percent.EFFECT: aerosol generating product is proposed.15 cl, 5 dwg

Description

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

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

[0003] A number of prior art documents describe aerosol-generating devices for consuming aerosol-generating articles. Such devices include, for example, electrically heated aerosol-generating devices in which the aerosol is generated by transferring heat from one or more electrical heating elements of the aerosol-generating device to an aerosol-generating substrate of the heated aerosol-generating article. For example, electrically heated aerosol-generating devices have been proposed that comprise an internal heating plate that is adapted for insertion into an aerosol-generating substrate. The use of an aerosol-generating article in combination with an external heating system is also known.For example, document WO 2020 / 115151 describes the provision of one or more heating elements located around the periphery of an aerosol-generating article when the aerosol-generating article is housed within the cavity of an aerosol-generating device. Alternatively, document WO 2015 / 176898 proposed inductively heated aerosol-generating articles comprising an aerosol-generating substrate and a susceptor located within the aerosol-generating substrate.

[0004] Known heated tobacco products typically contain a single tobacco-containing substrate. Changes in the internal structure of the tobacco-containing substrate can affect the resistance to draw of the tobacco-containing substrate and, therefore, the resistance to draw (RTD) of the tobacco product. Such changes may result, for example, from manufacturing defects or the presence of contaminants. Therefore, tobacco products may have one or more defects, such as inconsistencies in resistance to draw between one tobacco product and another. Such inconsistencies may be particularly pronounced in tobacco products with 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. Therefore, inconsistencies in the draw resistance of tobacco products can lead to changes in the composition and temperature of the aerosol generated by the tobacco product. For example, during the manufacture of a tobacco-containing substrate, gravitational settling of the substrate material can lead to the formation of several relatively large channels through the tobacco-containing substrate. When heated, the tobacco-containing substrate generates an aerosol that may preferentially flow through these channels. Therefore, the presence of relatively large channels through the tobacco-containing substrate can affect the composition of the aerosol delivered to the user. Therefore, the presence of relatively large channels through the tobacco-containing substrate can result in the aerosol reaching the user at a temperature that may be uncomfortable.

[0006] Tobacco-containing substrates are typically heated to significantly lower temperatures than those reached by the combustion front in a conventional cigarette. This can impact the release of nicotine from the tobacco-containing substrate and the delivery of nicotine to the consumer. At the same time, if the heating temperature is increased in an attempt to enhance nicotine delivery, the generated aerosol typically needs to be cooled to a greater extent and more quickly before reaching the consumer. Some well-known heated tobacco products incorporate a ventilation zone to cool the generated aerosol before it reaches the consumer. Increasing the ventilation level can increase the cooling of the generated aerosol. However, increasing the ventilation level can increase the impact of the tobacco product's draw resistance on the composition and temperature of the aerosol delivered to the user.

[0007] It would therefore be desirable to provide an aerosol generating product in which the quality and consistency of the aerosol delivered to the user upon successive puffs is improved compared to known heated tobacco products.

[0008] The present invention relates to an aerosol-generating article comprising an aerosol-generating rod for producing 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. An aerosol-generating product may have a ventilation rate of at least 40 percent.

[0009] According to a first aspect of the present invention, there is provided an aerosol-generating article comprising an aerosol-generating rod for producing an inhalable aerosol upon heating, wherein the aerosol-generating rod comprises: 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, wherein the total combined length of the first aerosol-generating segment and the second aerosol-generating segment is at least 20 millimeters, and wherein the aerosol-generating article has a ventilation level of at least 40 percent.

[0010] In a preferred embodiment, an aerosol-generating article is provided, comprising an aerosol-generating rod for producing an inhalable aerosol upon heating, wherein the aerosol-generating rod comprises: 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, wherein the total combined length of the first aerosol-generating segment and the second aerosol-generating segment is at least 20 millimeters, wherein the length of the first aerosol-generating segment is approximately equal to the length of the second aerosol-generating segment, and wherein the aerosol-generating article has a ventilation level of at least 40 percent.

[0011] In a preferred embodiment, an aerosol-generating article is provided, comprising an aerosol-generating rod for producing an inhalable aerosol upon heating, wherein the aerosol-generating rod comprises: 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, wherein the total combined length of the first aerosol-generating segment and the second aerosol-generating segment is at least 20 millimeters, wherein the composition of the first aerosol-generating segment is substantially the same as the composition of the second aerosol-generating segment, and wherein the aerosol-generating article has a ventilation level of at least 40 percent.

[0012] In a preferred embodiment, an aerosol generating article is provided, comprising an aerosol generating rod for producing an inhalable aerosol upon heating, wherein the aerosol generating rod comprises: 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, wherein the total combined length of the first aerosol-generating segment and the second aerosol-generating segment is at least 20 millimeters, wherein the length of the first aerosol-generating segment is approximately equal to the length of the second aerosol-generating segment, wherein the composition of the first aerosol-generating segment is substantially the same as the composition of the second aerosol-generating segment, and wherein the aerosol-generating article has a ventilation level of at least 40 percent.

[0013] The present invention 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 housing at least a portion of the aerosol generating article. The aerosol generating device may comprise a heater. The heater may be configured to heat an aerosol generating rod of the aerosol generating article when the aerosol generating article is positioned within the heating chamber.

[0014] According to a second aspect of the present invention, there is provided an aerosol generating system comprising: an aerosol generating article according to the first aspect of the present invention; and an aerosol generating device comprising a heating chamber for accommodating at least a portion 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 placed inside the heating chamber.

[0015] In the context of this document, in relation to the present invention, the term "aerosol generating article" is used to describe an article comprising an aerosol generating substrate that is heated to generate an inhalable aerosol for delivery to a user.

[0016] In the context of this document, in relation to the present invention, the term "aerosol-generating substrate" is used to describe a substrate containing an aerosol-generating material that is capable of releasing, upon heating, volatile compounds that can generate an aerosol.

[0017] In the context of this document, the term "aerosol" is used to describe a dispersion of solid particles or liquid droplets, or a combination of solid particles and liquid droplets, in a gas. An aerosol may be visible or invisible. An aerosol may include vapors of substances that are typically liquid or solid at room temperature, as well as solid particles or liquid droplets, or a combination of solid particles and liquid droplets.

[0018] In the context of this document, in relation to 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.

[0019] In the context of this document, in relation to the present invention, the term "rod" is used to describe a generally cylindrical element with a substantially circular, oval or elliptical cross-section.

[0020] The aerosol-generating articles of the present invention have a proximal end through which, during use, the aerosol exits the aerosol-generating article for delivery to the user. The proximal end of the aerosol-generating article may also be referred to as the downstream end or mouthpiece end of the aerosol-generating article. During use, the user draws directly or indirectly on the proximal end of the aerosol-generating article to inhale the aerosol generated by the aerosol-generating article.

[0021] The aerosol-generating articles of the present invention have a distal end. The distal end is opposite 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.

[0022] The components of the aerosol-generating articles according to the present invention may be described as upstream or downstream relative to each other based on their relative positions between the proximal end of the aerosol-generating article and the distal end of the aerosol-generating article.

[0023] In the context of this document, the term "longitudinal" 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 a longitudinal direction.

[0024] In the context of this document, in relation to the present invention, the term "length" is used to describe the maximum dimension of the aerosol-generating article and the components of the aerosol-generating article in the longitudinal direction.

[0025] In the context of this document, the term "transverse" is used to describe a direction perpendicular to the longitudinal direction. Unless otherwise specified, references to a "section" of an aerosol-generating article or a component of an aerosol-generating article refer to a cross-section.

[0026] In the context of this document, the term "ventilation level" is used to refer to the volumetric ratio between the airflow entering the aerosol-generating article through the ventilation zone (ventilation airflow) and the sum of the aerosol-containing airflow and the ventilation airflow. The higher the ventilation level, the greater the dilution of the aerosol flow delivered to the consumer.

[0027] Aerosol-generating articles according to a first aspect of the present invention comprise an aerosol-generating rod for producing an inhalable aerosol upon heating, wherein the aerosol-generating rod comprises: a first aerosol-generating segment containing a first aerosol-generating substrate; and a second aerosol-generating segment located upstream of the first aerosol-generating segment and containing a second aerosol-generating substrate, wherein the total combined length of the first aerosol-generating segment and the second aerosol-generating segment is at least about 20 millimeters, and wherein the aerosol-generating article has a ventilation level of at least about 40 percent.The inclusion of these features in the aerosol generating articles according to the first aspect of the present invention may improve the quality and consistency of the aerosol generated by one aerosol generating article relative to another, which is advantageous.

[0028] An aerosol-generating rod comprising a first aerosol-generating segment and a second aerosol-generating segment can minimize or eliminate the impact on the draw resistance that a change in the internal structure of one of the aerosol-generating segments can have on the entire aerosol-generating rod and, consequently, the aerosol-generating article. As discussed above, the impact of a change in the internal structure of an aerosol-generating segment on the overall draw resistance of an aerosol-generating article can be particularly pronounced in aerosol-generating articles comprising one relatively long aerosol-generating segment (e.g., at least 20 millimeters). An aerosol-generating rod comprising a first aerosol-generating segment and a second aerosol-generating segment can thus improve the stability of the draw resistance of the aerosol-generating article.This can improve the quality and stability of the aerosol delivered to the user by the aerosol-generating product. This can be particularly advantageous if the aerosol-generating product has a relatively high ventilation rate (e.g., at least 40 percent).

[0029] The aerosol-generating rod comprises a first aerosol-generating segment and a second aerosol-generating segment. The first aerosol-generating segment is physically distinct from the second aerosol-generating segment.

[0030] Preferably, the second aerosol-generating segment is located at the upstream end of the aerosol-generating rod. Preferably, the first aerosol-generating segment is located at the downstream end of the aerosol-generating rod.

[0031] Preferably, the first aerosol-generating segment and the second aerosol-generating segment are aligned end-to-end. That is, the downstream end of the second aerosol-generating segment is preferably adjacent to the upstream end of the first aerosol-generating segment. Preferably, substantially the entire surface of the downstream end of the second aerosol-generating segment is adjacent to substantially the entire surface of the upstream end of the first aerosol-generating segment.

[0032] Preferably, the aerosol generating rod consists of a first aerosol generating segment and a second aerosol generating segment.

[0033] The total combined length of the first aerosol-generating segment and the second aerosol-generating segment is at least 20 millimeters. Preferably, the total combined length of the first aerosol-generating segment and the second aerosol-generating segment is at least 25 millimeters. More preferably, the total combined length of the first aerosol-generating segment and the second aerosol-generating segment is at least 30 millimeters.

[0034] The combined total length of the first aerosol-generating segment and the second aerosol-generating segment is preferably less than 50 millimeters. Preferably, the combined total length of the first aerosol-generating segment and the second aerosol-generating segment is less than 45 millimeters. More preferably, the combined total length of the first aerosol-generating segment and the second aerosol-generating segment is less than 40 millimeters.

[0035] For example, the total combined length of the first aerosol generating segment and the second aerosol generating segment is preferably from 20 millimeters to 50 millimeters, or from 20 millimeters to 45 millimeters, or from 20 millimeters to 40 millimeters, or from 25 millimeters to 50 millimeters, or from 25 millimeters to 45 millimeters, or from 25 millimeters to 40 millimeters, or from 30 millimeters to 50 millimeters, or from 30 millimeters to 45 millimeters, or from 30 millimeters to 40 millimeters.

[0036] In an aerosol-generating rod containing a single aerosol-generating segment, increasing the length of a single aerosol-generating segment may increase the effect that a change in the internal structure of a single aerosol-generating segment may have on the single aerosol-generating segment and, thus, the aerosol-generating rod. This may increase the level of nonconformity between aerosol-generating products containing an aerosol-generating rod containing a single aerosol-generating segment.Thus, an aerosol-generating article according to the present invention, comprising an aerosol-generating rod having a first aerosol-generating segment and a second aerosol-generating segment, can be particularly effective in minimizing or eliminating the effect that a change in the internal structure of one of the aerosol-generating segments can have on the aerosol-generating rod, wherein the total combined length of the first aerosol-generating segment and the second aerosol-generating segment is relatively high.

[0037] Preferably, the length of the second aerosol-generating segment is approximately equal to the length of the first aerosol-generating segment. This can help minimize or eliminate the impact that altering the internal structure of the other aerosol-generating segment may have on the entire aerosol-generating rod. Approximately equal lengths of the first and second aerosol-generating segments can also simplify the manufacture of the aerosol-generating rod.

[0038] Preferably, the length of the second aerosol generating segment differs by an amount within 2 millimeters from the length of the first aerosol generating segment, or within 1 millimeter from the length of the first aerosol generating segment.

[0039] Preferably, the length of the second aerosol generating segment differs by an amount within 10 percent of the length of the first aerosol generating segment, or within 5 percent of the length of the first aerosol generating segment, or within 3 percent of the length of the first aerosol generating segment.

[0040] The relative lengths of the first aerosol generating segment and the second aerosol generating segment can be selected to optimize aerosol delivery.

[0041] In some embodiments, the length of the second aerosol-generating segment may be greater than the length of the first aerosol-generating segment. That is, the second aerosol-generating segment may be longer than the first aerosol-generating segment.

[0042] In some embodiments, the length of the second aerosol-generating segment may be at least 3 millimeters longer than the length of the first aerosol-generating segment. For example, the length of the second aerosol-generating segment may be at least 4 millimeters longer, at least 5 millimeters longer, or at least 6 millimeters longer than the length of the first aerosol-generating segment.

[0043] In some embodiments, the length of the second aerosol-generating segment may be no more than 12 millimeters longer than the length of the first aerosol-generating segment. For example, the second aerosol-generating segment may be no more than 10 millimeters longer, no more than 9 millimeters longer, or no more than 8 millimeters longer than the length of the first aerosol-generating segment.

[0044] In some embodiments, the length of the second aerosol generating segment may be approximately 7 millimeters longer than the length of the first aerosol generating segment.

[0045] In some embodiments, the ratio of the length of the first aerosol-generating segment to the length of the second aerosol-generating segment may be no more than 1. For example, the ratio of the length of the first aerosol-generating segment to the length of the second aerosol-generating segment may be no more than 0.8, no more than 0.6, or no more than 0.5.

[0046] In some embodiments, the ratio of the length of the first aerosol-generating segment to the length of the second aerosol-generating segment may be at least 0.1. For example, the ratio of the length of the first aerosol-generating segment to the length of the second aerosol-generating segment may be at least 0.2, at least 0.3, or at least 0.4.

[0047] In some embodiments, the ratio of the length of the first aerosol-generating segment to the length of the second aerosol-generating segment may be from 0.1 to 1, from 0.2 to 0.8, from 0.3 to 0.6, or from 0.4 to 0.5. For example, the ratio of the length of the first aerosol-generating segment to the length of the second aerosol-generating segment may be approximately 0.4.

[0048] In some embodiments, the length of the first aerosol-generating segment may be greater than the length of the second aerosol-generating segment. That is, the first aerosol-generating segment may be longer than the second aerosol-generating segment.

[0049] In some embodiments, the length of the first aerosol-generating segment may be at least 3 millimeters longer than the length of the second aerosol-generating segment. For example, the first aerosol-generating segment may be at least 4 millimeters longer, at least 5 millimeters longer, or at least 6 millimeters longer than the length of the second aerosol-generating segment.

[0050] In some embodiments, the length of the first aerosol-generating segment may be no more than 12 millimeters longer than the length of the second aerosol-generating segment. For example, the first aerosol-generating segment may be no more than 10 millimeters longer, no more than 9 millimeters longer, or no more than 8 millimeters longer than the length of the second aerosol-generating segment.

[0051] In some embodiments, the length of the first aerosol generating segment may be approximately 7 millimeters longer than the length of the second aerosol generating segment.

[0052] In some embodiments, the ratio of the length of the second aerosol-generating segment to the length of the first aerosol-generating segment may be no more than 1. For example, the ratio of the length of the second aerosol-generating segment to the length of the first aerosol-generating segment may be no more than 0.8, no more than 0.6, or no more than 0.5.

[0053] In some embodiments, the ratio of the length of the second aerosol-generating segment to the length of the first aerosol-generating segment may be at least 0.1. For example, the ratio of the length of the second aerosol-generating segment to the length of the first aerosol-generating segment may be at least 0.2, at least 0.3, or at least 0.4.

[0054] In some embodiments, the ratio of the length of the second aerosol-generating segment to the length of the first aerosol-generating segment may be from 0.1 to 1, from 0.2 to 0.8, from 0.3 to 0.6, or from 0.4 to 0.5. For example, the ratio of the length of the second aerosol-generating segment to the length of the first aerosol-generating segment may be approximately 0.4.

[0055] Preferably, the first aerosol-generating segment has a length of at least approximately 10 millimeters. More preferably, the length of the first aerosol-generating segment is at least 12.5 millimeters. More preferably, the length of the first aerosol-generating segment is at least 15 millimeters.

[0056] Preferably, the first aerosol-generating segment has a length less than or equal to 25 millimeters. Preferably, the first aerosol-generating segment has a length less than or equal to 22.50 millimeters. More preferably, the first aerosol-generating segment has a length less than or equal to 20 millimeters.

[0057] For example, the length of the first aerosol generating segment is preferably from 10 millimeters to 25 millimeters, or from 10 millimeters to 22.5 millimeters, or from 10 millimeters to 20 millimeters, or from 12.5 millimeters to 25 millimeters, or from 12.5 millimeters to 22.5 millimeters, or from 12.5 millimeters to 20 millimeters, or from 15 millimeters to 25 millimeters, or from 15 millimeters to 22.5 millimeters, or from 15 millimeters to 20 millimeters.

[0058] Preferably, the second aerosol-generating segment has a length of at least 10 millimeters. More preferably, the length of the second aerosol-generating segment is at least 12.5 millimeters. More preferably, the length of the second aerosol-generating segment is at least 15 millimeters.

[0059] The length of the second aerosol-generating segment is preferably less than 25 millimeters. Preferably, the second aerosol-generating segment is less than 22.5 millimeters in length. More preferably, the length of the second aerosol-generating segment is less than 20 millimeters.

[0060] For example, the length of the second aerosol generating segment is preferably from 10 millimeters to 25 millimeters, or from 10 millimeters to 22.5 millimeters, or from 10 millimeters to 20 millimeters, or from 12.5 millimeters to 25 millimeters, or from 12.5 millimeters to 22.5 millimeters, or from 12.5 millimeters to 20 millimeters, or from 15 millimeters to 25 millimeters, or from 15 millimeters to 22.5 millimeters, or from 15 millimeters to 20 millimeters.

[0061] If the aerosol generating rod is composed of a first aerosol generating segment and a second aerosol generating segment, and the first aerosol generating segment and the second aerosol generating segment are aligned end to end, the total combined length of the first aerosol generating segment and the second aerosol generating segment is the same as the length of the aerosol generating rod.

[0062] The aerosol-generating rod preferably has a length of at least 20 millimeters. Preferably, the aerosol-generating rod has a length of at least 25 millimeters. More preferably, the aerosol-generating rod has a length of at least 30 millimeters.

[0063] Preferably, the aerosol-generating rod has a length less than or equal to 50 millimeters. Preferably, the aerosol-generating rod has a length less than or equal to 45 millimeters. More preferably, the aerosol-generating rod has a length less than or equal to 40 millimeters.

[0064] For example, the aerosol generating 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.

[0065] 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.

[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 less than or equal to 0.60. 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 less than or equal to 0.55. 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 less than or equal to 0.50.

[0067] 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 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 between the length of the aerosol-generating rod and 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 between the length of the aerosol generating rod and 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.

[0068] The ratio of the length of the first aerosol-generating 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-generating 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-generating segment to the total length of the aerosol-generating article is at least 0.15.

[0069] The ratio of the length of the first aerosol-generating segment to the total length of the aerosol-generating article is preferably less than or equal to 0.30. Preferably, the ratio of the length of the first aerosol-generating segment to the total length of the aerosol-generating article is preferably less than or equal to 0.27. More preferably, the ratio of the length of the first aerosol-generating segment to the total length of the aerosol-generating article is less than or equal to 0.25.

[0070] In some embodiments, the ratio of the length of the first aerosol-generating segment to the total length of the aerosol-generating article is from 0.10 to 0.30, preferably from 0.10 to 0.27, more preferably from 0.10 to 0.25. In other embodiments, the ratio of the length of the first aerosol-generating segment to the total length of the aerosol-generating article is from 0.12 to 0.30, preferably from 0.12 to 0.27, more preferably from 0.12 to 0.25. In further embodiments, the ratio of the length of the first aerosol-generating segment to the total length of the aerosol-generating article is from 0.15 to 0.30, preferably from 0.15 to 0.27, more preferably from 0.30 to 0.25.

[0071] The ratio of the length of the second aerosol-generating 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-generating 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-generating segment to the total length of the aerosol-generating article is at least 0.15.

[0072] The ratio of the length of the second aerosol-generating segment to the total length of the aerosol-generating article is preferably less than or equal to 0.30. Preferably, the ratio of the length of the second aerosol-generating segment to the total length of the aerosol-generating article is less than or equal to 0.27. More preferably, the ratio of the length of the second aerosol-generating segment to the total length of the aerosol-generating article is less than or equal to 0.25.

[0073] In some embodiments, the ratio of the length of the second aerosol-generating segment to the total length of the aerosol-generating article is from 0.10 to 0.30, preferably from 0.10 to 0.27, more preferably from 0.10 to 0.25. In other embodiments, the ratio of the length of the second aerosol-generating segment to the total length of the aerosol-generating article is from 0.12 to 0.30, preferably from 0.12 to 0.27, more preferably from 0.12 to 0.25. In further embodiments, the ratio of the length of the second aerosol-generating segment to the total length of the aerosol-generating article is from 0.15 to 0.30, preferably from 0.15 to 0.27, more preferably from 0.30 to 0.25.

[0074] The ratio between the length of the aerosol generating rod and the total length of the aerosol generating article is preferably at least 0.20. Preferably, the ratio between the length of the aerosol generating rod and the total length of the aerosol generating article is at least 0.25. More preferably, the ratio between the length of the aerosol generating rod and the total length of the aerosol generating article is at least 0.30.

[0075] The ratio between the length of the aerosol generating rod and the total length of the aerosol generating article is preferably less than or equal to 0.60. Preferably, the ratio between the length of the aerosol generating rod and the total length of the aerosol generating article is less than or equal to 0.55. More preferably, the ratio between the length of the aerosol generating rod and the total length of the aerosol generating article is less than or equal to 0.50.

[0076] In some embodiments, the ratio between the length of the aerosol generating rod and 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 between the length of the aerosol generating rod and 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 between the length of the aerosol generating rod and 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.

[0077] The aerosol generating rod preferably has an outer diameter that is approximately equal to the outer diameter of the aerosol generating article.

[0078] For the purposes of this document, the "outer diameter" of an aerosol-generating article component may be calculated as the average of a plurality of measurements of the diameter of the aerosol-generating article component taken at different locations along the length of the aerosol-generating article component.

[0079] Preferably, the aerosol-generating rod has an outer diameter of at least approximately 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.

[0080] The aerosol-generating rod preferably has an outer diameter of less than or equal to 8 millimeters. More preferably, the aerosol-generating rod has an outer diameter of less than or equal to 7.5 millimeters. Even more preferably, the aerosol-generating rod has an outer diameter of less than or equal to approximately 7 millimeters.

[0081] In general, 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 sufficient quantities of vaporizable compounds are released from the aerosol-generating substrates to form the desired amount of aerosol. At the same time, without being limited by theory, it should be understood that a smaller aerosol-generating rod diameter ensures that the heat supplied to the aerosol-generating article more quickly penetrates into the entire volume of the aerosol-generating substrates. However, when the aerosol-generating rod diameter is too small, the volume-to-surface ratio of one or both aerosol-generating substrates becomes less favorable, since the amount of available aerosol-generating substrate decreases.

[0082] An aerosol-generating rod diameter within the ranges described herein provides a particular advantage in terms of the balance between energy consumption and aerosol delivery. This advantage is particularly noticeable when an aerosol-generating article comprising an aerosol-generating rod having a diameter as described herein is used in conjunction with an external heater located around the periphery of the aerosol-generating article. It has been observed that under such operating conditions, less thermal energy is required to achieve a sufficiently high temperature in the core of the aerosol-generating rod and in the core of the article as a whole. Thus, when operating at low temperatures, the desired target temperature in the core of the aerosol-generating substrate can be achieved within a desirably reduced time frame and with lower energy consumption.

[0083] Using an aerosol-generating rod with a smaller diameter can also advantageously reduce the overall weight of tobacco material required in the aerosol-generating product while maintaining the ability to produce desired aerosol levels. Consequently, tobacco waste can be reduced.

[0084] 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.

[0085] Preferably, one or both of the first aerosol-generating segment and the second aerosol-generating segment have a substantially circular cross-section. For example, one or both of the first aerosol-generating segment and the second aerosol-generating segment are preferably substantially cylindrical.

[0086] Preferably, the outer diameter of the first aerosol generating segment is approximately equal to the outer diameter of the second aerosol generating segment.

[0087] Preferably, the outer diameter of one or both of the first aerosol generating segment is approximately equal to the outer diameter of the aerosol generating rod.

[0088] Preferably, the outer diameter of one or both of the first aerosol generating segment is approximately equal to the outer diameter of the aerosol generating article.

[0089] Preferably, the outer diameter of the first aerosol generating segment is from 5 millimeters to 8 millimeters, more preferably from 5.25 millimeters to 7.5 millimeters, more preferably from 5.5 millimeters to 7 millimeters.

[0090] Preferably, the outer diameter of the second aerosol generating segment is from 5 millimeters to 8 millimeters, more preferably from 5.25 millimeters to 7.5 millimeters, more preferably from 5.5 millimeters to 7 millimeters.

[0091] The average cross-sectional area of ​​the first aerosol-generating 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, more preferably at least 90 percent of the average cross-sectional area of ​​the aerosol-generating article.

[0092] The cross-sectional area of ​​the first aerosol-generating 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, more preferably at least 90 percent of the average cross-sectional area of ​​the aerosol-generating article.

[0093] The average cross-sectional area of ​​the second aerosol-generating 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, more preferably at least 90 percent of the average cross-sectional area of ​​the aerosol-generating article.

[0094] The cross-sectional area of ​​the second aerosol-generating 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, more preferably at least 90 percent of the average cross-sectional area of ​​the aerosol-generating article.

[0095] Preferably, the shape and size of the first aerosol-generating segment are the same as the shape and size of the second aerosol-generating segment. This can simplify the manufacture of the aerosol-generating rod.

[0096] Preferably, the density of the second aerosol-generating substrate is approximately equal to the density of the first aerosol-generating substrate. This can advantageously simplify the fabrication of the aerosol-generating rod.

[0097] The term "density" used in this document with respect to aerosol-generating substrates refers to the bulk density of the aerosol-generating substrate. This can be calculated by measuring the total weight of the aerosol-generating substrate and dividing it by the volume of the aerosol-generating substrate segment (excluding any wrapper).

[0098] Preferably, the density of the second aerosol-generating substrate differs by an amount within 50 mg per cubic centimeter from the density of the first aerosol-generating substrate, or within 30 mg per cubic centimeter from the density of the first aerosol-generating substrate, or within 10 mg per cubic centimeter from the density of the first aerosol-generating substrate.

[0099] Preferably, the density of the second aerosol-generating substrate differs by an amount within 10 percent of the density of the first aerosol-generating substrate, or within 5 percent of the density of the first aerosol-generating substrate, or within 3 percent of the density of the first aerosol-generating substrate.

[0100] The relative densities of the first aerosol-generating substrate and the second aerosol-generating substrate can be selected to optimize aerosol delivery.

[0101] In some embodiments, the density of the second aerosol-generating substrate may be greater than the density of the first aerosol-generating substrate.

[0102] In some embodiments, the density of the second aerosol-generating substrate may be at least 100 mg per cubic centimeter higher than the density of the first aerosol-generating substrate, or at least 150 mg per cubic centimeter higher than the density of the first aerosol-generating substrate, or at least 200 mg per cubic centimeter higher than the density of the first aerosol-generating substrate. The density of the second aerosol-generating substrate may be 500 mg per cubic centimeter higher than the density of the first aerosol-generating substrate.

[0103] In some embodiments, the density of the second aerosol-generating substrate may be at least 1.2 times the density of the first aerosol-generating substrate, or at least 1.5 times the density of the first aerosol-generating substrate, or at least twice the density of the first aerosol-generating substrate. The density of the second aerosol-generating substrate may exceed the density of the first aerosol-generating substrate by up to four times.

[0104] In some embodiments, the density of the second aerosol-generating substrate may be greater than the density of the first aerosol-generating substrate.

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

[0106] In some embodiments, the density of the first aerosol-generating substrate may be at least 1.2 times the density of the second aerosol-generating substrate, or at least 1.5 times the density of the second aerosol-generating substrate, or at least twice the density of the second aerosol-generating substrate. The density of the first aerosol-generating substrate may exceed the density of the second aerosol-generating substrate by up to four times.

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

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

[0109] For example, the density of the first aerosol-generating 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.

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

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

[0112] For example, the density of the second aerosol-generating 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-generating substrate is a solid aerosol-generating substrate. Preferably, the second aerosol-generating substrate is a solid aerosol-generating substrate.

[0114] Preferably, the first aerosol-generating substrate has substantially the same composition as the second aerosol-generating substrate. This can simplify the fabrication of the aerosol-generating rod.

[0115] The first aerosol-generating substrate preferably contains one or more aerosol-forming substances. The second aerosol-generating substrate preferably contains one or more aerosol-forming substances.

[0116] The aerosol former may be any suitable known compound or mixture of compounds that, when used, promotes the formation of a dense and stable aerosol. The aerosol former may provide the aerosol with substantial resistance to thermal degradation at temperatures typically encountered during use of the aerosol-generating article. Suitable aerosol formers include, for example: polyhydric alcohols, such as, for example, triethylene glycol, 1,3-butanediol, propylene glycol and glycerol; esters of polyhydric alcohols, such as, for example, glycerol mono-, di- or triacetate; aliphatic esters of mono-, di- or polycarboxylic acids, such as, for example, dimethyl dodecanedioate and dimethyl tetradecanedioate; and combinations thereof.

[0117] Preferably, one or more aerosol forming substances comprise one or both of glycerin and propylene glycol. One or more aerosol forming substances may consist of one or both of glycerin and propylene glycol.

[0118] Preferably, one or both of the first aerosol-generating substrate and the second aerosol-generating substrate contain glycerin.

[0119] The first aerosol-generating substrate and the second aerosol-generating substrate may contain the same aerosol-generating substance (or aerosol-generating substances) relative to each other, or may use different aerosol-generating substances.

[0120] Preferably, the content of the aerosol-forming substance in the first aerosol-generating substrate is approximately equal to the content of the aerosol-forming substance in the second aerosol-generating substrate, based on dry weight. This can advantageously simplify the manufacture of the aerosol-generating rod.

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

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

[0123] Preferably, the content of the aerosol-forming substance in the second aerosol-generating substrate is within 10 percent of the content of the aerosol-forming substance in the first aerosol-generating substrate. For example, if the content of the aerosol-forming substance in the first aerosol-generating substrate is 20 percent by weight based on dry weight, and the content of the aerosol-forming substance in the second aerosol-generating substrate is within 10 percent of the content of the aerosol-forming substance in the first aerosol-generating substrate, then the second aerosol-generating substrate has an aerosol-forming substance content of 18 percent by weight to 22 percent by weight based on dry weight.

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

[0125] Preferably, the glycerin content of the first aerosol-generating substrate is approximately equal to the glycerin content of the second aerosol-generating substrate, based on dry weight. This can advantageously simplify the manufacture of the aerosol-generating rod.

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

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

[0128] The relative contents of the aerosol-forming substance in the first aerosol-generating substrate and the second aerosol-generating substrate may be selected to optimize aerosol delivery.

[0129] In some embodiments, the content of the aerosol-forming substance in the second aerosol-generating substrate may be greater than the content of the aerosol-forming substance in the first aerosol-generating substrate, based on dry weight.

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

[0131] The content of the aerosol-forming substance in the second aerosol-generating substrate may be at least 20 percentage points higher than the content of the aerosol-forming substance in the first aerosol-generating substrate, or at least 25 percent higher than the content of the aerosol-forming substance in the first aerosol-generating substrate, based on dry weight. The content of the aerosol-forming substance in the second aerosol-generating substrate may be up to 60 percent higher than the content of the aerosol-forming substance in the first aerosol-generating substrate.

[0132] In some embodiments, the content of the aerosol-forming substance in the second aerosol-generating substrate may be at least 1.2 times the content of the aerosol-forming substance in the first aerosol-generating substrate, or at least 1.5 times the content of the aerosol-forming substance in the first aerosol-generating substrate, or at least two times the content of the aerosol-forming substance in the first aerosol-generating substrate, based on dry weight. The content of the aerosol-forming substance in the second aerosol-generating substrate may exceed the content of the aerosol-forming substance in the first aerosol-generating substrate by up to four times.

[0133] In some embodiments, the content of the aerosol forming substance in the first aerosol generating substrate may be greater than the content of the aerosol forming substance in the second aerosol generating substrate, based on dry weight.

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

[0135] In some embodiments, the content of the aerosol-forming substance in the first aerosol-generating substrate may be at least 1.2 times the content of the aerosol-forming substance in the second aerosol-generating substrate, or at least 1.5 times the content of the aerosol-forming substance in the second aerosol-generating substrate, or at least two times the content of the aerosol-forming substance in the first aerosol-generating substrate, based on dry weight. The content of the aerosol-forming substance in the first aerosol-generating substrate may be up to four times the content of the aerosol-forming substance in the second aerosol-generating substrate.

[0136] Preferably, the first aerosol-generating substrate contains at least 5 percent by weight of the aerosol-forming substance based on the dry weight of the first aerosol-generating substrate, more preferably at least 7 percent by weight of the aerosol-forming substance based on the dry weight of the first aerosol-generating substrate, at least 10 percent by weight of the aerosol-forming substance based on the dry weight of the first aerosol-generating substrate.

[0137] Preferably, the first aerosol-generating substrate contains less than or exactly 80 percent by weight of the aerosol-forming substance, based on the dry weight of the first aerosol-generating substrate. More preferably, the first aerosol-generating substrate contains less than or exactly 60 percent by weight of the aerosol-forming substance, based on the dry weight of the first aerosol-generating substrate. More preferably, the first aerosol-generating substrate contains less than or exactly 40 percent by weight of the aerosol-forming substance, based on the dry weight of the first aerosol-generating substrate. In some embodiments, the first aerosol-generating substrate may contain less than or exactly 20 percent by weight of the aerosol-forming substance, or less than or exactly 15 percent by weight, based on the dry weight of the first aerosol-generating substrate.

[0138] For example, the first aerosol-generating substrate may contain from 5 percent to 80 percent, or from 5 percent to 60 percent, or from 5 percent to 40 percent, or from 5 percent to 20 percent, or from 5 percent to 15 percent, or from 7 percent to 80 percent, or from 7 percent to 60 percent, or from 7 percent to 40 percent, or from 7 percent to 20 percent, or from 7 percent to 15 percent, or from 10 percent to 80 percent, or from 10 percent to 60 percent, or from 10 percent to 40 percent, or from 10 percent to 20 percent, or from 10 percent to 15 percent by weight of an aerosol-forming substance, based on the dry weight of the first aerosol-generating substrate.

[0139] Preferably, the second aerosol-generating substrate contains at least 5 percent by weight of the aerosol-forming substance based on the dry weight of the second aerosol-generating substrate, more preferably at least 7 percent by weight of the aerosol-forming substance based on the dry weight of the second aerosol-generating substrate, at least 10 percent by weight of the aerosol-forming substance based on the dry weight of the second aerosol-generating substrate.

[0140] Preferably, the second aerosol-generating substrate contains less than or exactly 80 percent by weight of the aerosol-forming agent, based on the dry weight of the second aerosol-generating substrate. More preferably, the second aerosol-generating substrate contains less than or exactly 60 percent by weight of the aerosol-forming agent, based on the dry weight of the second aerosol-generating substrate. More preferably, the second aerosol-generating substrate contains less than or exactly 40 percent by weight of the aerosol-forming agent, based on the dry weight of the second aerosol-generating substrate. In some preferred embodiments, the second aerosol-generating substrate may contain less than or exactly 20 percent by weight, or less than or exactly 15 percent by weight of the aerosol-forming agent, based on the dry weight of the second aerosol-generating substrate.

[0141] For example, the second aerosol-generating substrate may contain from 5 percent to 80 percent, or from 5 percent to 60 percent, or from 5 percent to 40 percent, or from 5 percent to 20 percent, or from 5 percent to 15 percent, or from 7 percent to 80 percent, or from 7 percent to 60 percent, or from 7 percent to 40 percent, or from 7 percent to 20 percent, or from 7 percent to 15 percent, or from 10 percent to 80 percent, or from 10 percent to 60 percent, or from 10 percent to 40 percent, or from 10 percent to 20 percent, or from 10 percent to 15 percent by weight of an aerosol-forming agent, based on the dry weight of the second aerosol-generating substrate.

[0142] Preferably, the first aerosol-generating substrate and the second aerosol-generating substrate are formed from the same type of substrate material. Suitable types of materials for use in the aerosol-generating article according to the present invention are described below and include, for example, cut tobacco filler, homogenized tobacco material such as a molded sheet, aerosol-generating films, and gel compositions. The first aerosol-generating substrate and the second aerosol-generating substrate can be formed from different types of material relative to each other.

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

[0144] In the context of the present description, the term "cut filler" is used to describe a mixture of ground plant material, such as tobacco plant material, including, in particular, one or more of leaf blades, processed stems and veins, as well as homogenized plant material.

[0145] Cut filler may also contain other cut products, tobacco filler or casing.

[0146] Preferably, the chopped filler comprises at least 25 percent of plant leaf blades, more preferably at least 50 percent of plant leaf blades, even more preferably at least 75 percent of plant leaf blades, and most preferably at least 90 percent of plant leaf blades. Preferably, the plant material is one of tobacco, mint, tea, and cloves. Most preferably, the plant material is tobacco. However, the present invention is equally applicable to other plant material that has the ability to release substances when exposed to heat that can subsequently form an aerosol.

[0147] Preferably, the cut filler comprises tobacco plant material comprising leaf blades of one or more of light tobacco, dark tobacco, aromatic tobacco, and filler tobacco. For the purposes of the present invention, the term "tobacco" refers to any plant belonging to the genus Nicotiana.

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

[0149] Preferably, the threads have a length of from about 10 millimeters to about 40 millimeters before the threads are combined to form an aerosol generating rod.

[0150] In preferred embodiments, the mass 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 generally provides sufficient material to form an aerosol.

[0151] Preferably, the cut filler is impregnated with an aerosol forming agent. Impregnation of the cut filler can be accomplished by spraying or other suitable application methods. The aerosol forming agent can be added to the mixture during the preparation of the cut filler. For example, the aerosol forming agent can be added to the mixture in a direct conditioning cylinder (DCCC). Conventional equipment can be used to add the aerosol forming agent to the cut filler. Suitable aerosol forming agents are described above.

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

[0153] In other preferred embodiments, 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 agglomerating plant particles. For example, sheets or webs of homogenized plant material for aerosol-generating substrates according to the present invention can be formed by agglomerating plant material particles obtained by grinding, crushing, or milling the plant material. The homogenized plant material can be obtained by molding, extrusion, papermaking, or any other suitable methods known in the art.

[0155] The homogenized plant material may 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, the term "sheet" in relation to the present invention 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 multiple balls or granules.

[0158] The homogenized plant material may be in the form of multiple strands, strips, or pieces. For the purposes of this document, the term "strand" describes an elongated element of material whose length significantly exceeds its width and thickness. The term "strand" should be understood to encompass strips, pieces, and any other homogenized plant material of similar shape. The strands of homogenized plant material may be formed from a sheet of homogenized plant material, for example, by cutting or dividing it into pieces, or by other methods, such as extrusion.

[0159] If the homogenized plant material is in the form of one or more sheets as described above, the sheets may be produced by a molding process. Alternatively, sheets of homogenized plant material may be produced by a papermaking process.

[0160] Each of the one or more sheets described herein may individually have a thickness of from approximately 100 micrometers to 600 micrometers, preferably from 150 micrometers to 300 micrometers, and most preferably from 200 micrometers to 250 micrometers. Individual thickness refers to the thickness of an individual sheet, while the cumulative thickness refers to the total thickness of all sheets that make up the aerosol-generating substrate.

[0161] Each of the one or more sheets as described herein may individually have a grammage of from 100 grams per square meter to 600 grams per square meter.

[0162] Each of the one or more sheets as described herein may individually have a density of from 0.3 grams per cubic centimeter up to 1.3 grams per cubic centimeter and 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 corrugated, folded, gathered and pleated. 0164 One or more sheets of homogenized plant material can be cut into threads, as mentioned above. In such embodiments, the first aerosol-generating substrate comprises a plurality of threads of homogenized plant material. The threads can be used to form a plug. Typically, the width of such threads is approximately 5 millimeters, or approximately 4 millimeters, or approximately 3 millimeters, or approximately 2 millimeters, or less. The length of the threads can be greater than approximately 5 millimeters, from approximately 5 millimeters to approximately 15 millimeters, from approximately 8 millimeters to approximately 12 millimeters, or approximately 12 millimeters. Preferably, the threads have substantially the same length relative to each other.

[0165] The homogenized plant material may contain from 2.5 percent to 95 percent by weight of plant particles, or from 5 percent to 90 percent by weight of plant particles, or from 10 percent to 80 percent by weight of plant particles, or from 15 percent to 70 percent by weight of plant particles, or from 20 percent to 60 percent by weight of plant particles, or from 30 percent to 50 percent by weight of plant particles, based on dry weight.

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

[0167] In the context of the present invention, the term "tobacco particles" describes particles of any plant belonging to the genus Nicotiana. The term "tobacco particles" encompasses ground or powdered tobacco leaf lamellas, ground or powdered tobacco leaf stems, tobacco dust, tobacco fines, and other particulate tobacco by-products generated during the processing, handling, and shipping of tobacco. In a preferred embodiment, the tobacco particles are substantially all derived from tobacco leaf lamellas. In contrast, separated 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 percentage of particulate plant material.

[0168] In preferred embodiments, the first aerosol-generating substrate comprises strands of homogenized tobacco material, wherein the strands of homogenized tobacco material weigh 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 generally allows for the production of sufficient material to form an aerosol.

[0169] In preferred embodiments, the second aerosol-generating substrate comprises strands of homogenized tobacco material, wherein the strands of homogenized tobacco material weigh 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-forming agent, nicotine, and one or more aerosol-forming agents. The aerosol-generating film may further comprise a cellulose-based reinforcing agent. The aerosol-generating film may further comprise water, preferably 30 percent by weight or less.

[0171] In the context of this document, the term "film" is used to describe a solid laminated element having a thickness that is less than its width or length. The film may be self-supporting. In other words, the film may have cohesive and mechanical properties such that the film, even if formed by casting a film-forming composition onto a supporting surface, can be separated from that supporting surface. Alternatively, the film may be supported on a support or sandwiched between other materials. This provides the potential for increased mechanical stability of the film.

[0172] The content of the aerosol-forming substance in the aerosol-generating film may be within the ranges specified above for the first aerosol-generating substrate.

[0173] In the context of the present invention, the term "cellulose-based film-forming agent" is used to describe a cellulose polymer capable of forming a continuous film on its own or in the presence of an auxiliary thickening agent.

[0174] Preferably, the cellulose-based 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 cellulose-based 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 cellulose-based film-forming agent is HPMC.

[0177] As used herein, the term "nicotine" is used to describe nicotine, nicotine base, or nicotine salt. In embodiments in which the aerosol-generating film comprises nicotine base or nicotine salt, the amounts of nicotine provided herein represent the amount of nicotine in free base form or the amount of protonated nicotine, respectively.

[0178] In alternative embodiments of the present invention, the first aerosol-generating substrate may comprise a gel composition that includes nicotine, at least one gelling agent, and an aerosol former. The gel composition is preferably substantially free of tobacco.

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

[0180] The term "gelling agent" refers to a compound that, when uniformly added to a 50 percent by weight water / 50 percent by weight glycerin mixture in an amount of approximately 0.3 percent by weight, forms a solid medium or support matrix resulting in gel formation. Gelling agents include, but are not limited to, gelling agents that provide cross-linking through hydrogen bonds and gelling agents that provide cross-linking through ionic bonds.

[0181] The term "hydrogen bond crosslinking gelling agent" refers to a gelling agent that forms non-covalent crosslinking bonds or physical crosslinking bonds through hydrogen bonding.

[0182] The gelling agent that enables cross-linking via hydrogen bonds may comprise one or more of galactomannan, gelatin, agarose, konjac gum, or agar. The gelling agent that enables cross-linking via hydrogen bonds may preferably comprise agar.

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

[0184] The gelling agent that provides cross-linking through ionic bonds may comprise low-acyl gellan, pectin, kappa-carrageenan, iota-carrageenan, or alginate. The gelling agent that provides cross-linking through ionic bonds may preferably comprise low-acyl gellan.

[0185] The gelling agent may include one or more biopolymers. The biopolymers may be formed from polysaccharides.

[0186] Biopolymers include, for example, gellan gums (natural, low acyl gellan gum, high acyl gellan gums, with low acyl gellan gum being preferred), xanthan gum, alginates (alginic acid), agar, guar gum, etc. The composition may preferably include 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] The second aerosol-generating substrate may be in the form of a cut filler or a homogenized tobacco material such as a molded sheet, or an aerosol-generating film, or a gel composition as described above.

[0188] Preferably, the second aerosol-generating substrate may comprise tobacco material. In certain preferred embodiments, the second aerosol-generating substrate comprises shredded tobacco material. For example, the shredded tobacco material may be in the form of cut filler as described above. 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 also comprises one or more elongated current-collecting elements within the aerosol-generating rod. For example, one or more elongated current-collecting elements may be arranged substantially longitudinally within the aerosol-generating rod and may be in thermal contact with the aerosol-generating substrate. If the aerosol-generating rod comprises one or more elongated current-collecting elements, one or both of the first and second aerosol-generating segments may include a current-collecting element extending in the longitudinal direction within this element. With such an arrangement, separate current-collecting elements may be provided in the first and second aerosol-generating segments.

[0190] In the context of this document, the term "current collector" refers to a material capable of converting electromagnetic energy into heat. When placed within a fluctuating electromagnetic field, eddy currents induced in the current collector cause the current collector to heat up. Because the current collector is placed in thermal contact with the aerosol-generating substrate, the aerosol-generating substrate is heated by the current collector.

[0191] When used to describe a current collecting member, the term "elongated" means that the current collecting member 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 current-collecting element may be located substantially in the longitudinal direction within the rod or segment. This means that the lengthwise dimension of the elongated current-collecting element may be approximately parallel to the longitudinal direction of the rod, for example, within a range of plus or minus 10 degrees parallel to the longitudinal direction of the rod. In preferred embodiments, the elongated current-collecting element may be positioned in a radially central position within the rod or segment and extend along the longitudinal axis of the rod or segment.

[0193] The current collecting element is preferably in the form of a pin, rod, strip or plate.

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

[0195] The current-collecting element may generally have a thickness of 0.01 millimeters to 2 millimeters, for example, 0.5 millimeters to 2 millimeters. In some embodiments, the current-collecting element preferably has a thickness of 10 micrometers to 500 micrometers, more preferably 10 micrometers to 100 micrometers.

[0196] Preferably, the elongated current-collecting element has a length equal to or shorter than the length of the aerosol-generating segment in which it is embedded. Preferably, the elongated current-collecting element has the same length as the aerosol-generating segment in which it is embedded.

[0197] The current collecting element may be formed from any material that can be inductively heated to a temperature sufficient to generate an aerosol from an aerosol-generating substrate. Preferred current collecting elements comprise metal or carbon.

[0198] A preferred current collector may comprise or consist of a ferromagnetic material, such as a ferromagnetic alloy, ferritic iron, ferromagnetic steel, or stainless steel. A suitable current collector may be made of or comprise aluminum.

[0199] Suitable current collector elements may comprise a non-metallic core with a metallic layer disposed on the non-metallic core, for example, with metallic tracks formed on the surface of a ceramic core. The current collector element may have a protective outer layer, for example, a protective ceramic layer or a protective glass layer, enclosing the current collector element. The current collector element may comprise a protective coating formed of glass, ceramic, or an inert metal, applied over the core material of the current collector element.

[0200] The current-receiving element is positioned in thermal contact with the aerosol-generating substrate of the aerosol-generating segment in which the current-receiving element is embedded. Thus, when the current-receiving element is heated, the aerosol-generating substrate is heated, and an aerosol is generated. Preferably, the current-receiving element is positioned in direct physical 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] If a first aerosol-generating substrate is surrounded by a first wrapper, and a second aerosol-generating substrate is surrounded by a second wrapper, the second wrapper is preferably separated from the first wrapper. Thus, each aerosol-generating segment can have its own separate filament around its respective aerosol-generating substrate.

[0203] An aerosol generating rod including first and second aerosol generating segments may be surrounded by an additional wrapper that can combine the aerosol generating segments and hold them in place relative to each other.

[0204] The wrapper surrounding the aerosol-generating rod may be a paper wrapper or a non-paper wrapper. Paper wrappers suitable for use in certain embodiments of the present invention are known in the art and include, but are not limited to: types of cigarette paper; and filter papers. Non-paper wrappers suitable for use in certain embodiments of the present invention are known in the art and include, but are not limited to, sheets of homogenized tobacco materials.

[0205] Paper wrapping can have a grammage of 15 g / m 2 up to 35 g / m 2 , preferably from 20 g / m 2 up to 30 g / m 2 .

[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 multiple layers. Preferably, the wrapper is formed from a multilayer sheet comprising a layer of aluminum.

[0208] The paper layer of the multilayer sheet can have a grammage of 35 g / m 2 up to 55 g / m 2 , preferably from 40 g / m 2 up to 50 g / m 2 .

[0209] The paper layer of the multi-layer 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 multilayer sheet can have a grammage of 12 g / m 2 up to 25 g / m 2 , preferably from 15 g / m 2 up to 20 g / m 2 .

[0211] The metal layer of the multilayer 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 substrate core can be a paper wrapper containing PVOH (polyvinyl alcohol) or silicone (or polysiloxane). The addition of PVOH (polyvinyl alcohol) or silicone (or polysiloxane) can improve the wrapper's grease barrier properties.

[0213] The paper wrapper containing PVOH or silicone (or polysiloxane) may have a grammage of 20 g / m2 to 50 g / m2, preferably 25 g / m2 to 45 g / m2, more preferably 30 g / m2 to 40 g / m2.

[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 substrate core may contain a flame retardant composition comprising one or more flame retardant compounds. The term "flame retardant compounds" is used herein to describe chemical compounds that, when added or otherwise incorporated into a supporting substrate, such as paper or plastic compounds, provide varying degrees of flame retardancy to the supporting substrate.

[0216] A number of suitable flame retardant compounds are known to those skilled in the art. In particular, several flame retardant compounds and compositions suitable for treating cellulosic materials are known and have been disclosed, and they can find use in the manufacture of wrappers for aerosol-generating articles in accordance with the present invention.

[0217] The wrapper containing the flame retardant composition may have a grammage of 20 g / m 2 up to 45 g / m 2 , preferably from 25 g / m 2 up to 40 g / m 2 , more preferably from 30 g / m 2 up to 35 g / m 2 .

[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 35 micrometers. The wrapper containing the flame retardant composition may have a thickness of less than or equal to 50 micrometers, preferably less than or equal to 45 micrometers, even more preferably less than or equal to 40 micrometers.

[0219] The aerosol-generating article according to the present invention preferably also 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 will be described in more detail within the framework of 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 can advantageously provide an aerosol cooling element for the aerosol-generating article.

[0224] A hollow tubular cooling element may be provided immediately downstream of the aerosol-generating rod. In other words, the hollow tubular cooling element may be adjacent to the downstream end of the aerosol-generating rod. The hollow tubular cooling element may define an upstream end of a 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] In the context of the present disclosure, the term "hollow tubular element" means a generally elongated element that defines a lumen or passage for air flow along its longitudinal axis. In particular, the term "tubular" will be used hereinafter to refer to a tubular element having a substantially cylindrical cross-section and defining at least one air flow channel that establishes continuous fluid communication between an upstream end of the tubular element and a downstream end of the tubular element. However, it should be understood that alternative geometries (e.g., alternative cross-sectional shapes) of the tubular element may be possible. The hollow tubular cooling element may be a stand-alone, separate element of the aerosol-generating article that has a specific length and thickness.

[0226] In the context of the present invention, the hollow tubular cooling element provides a channel for unrestricted flow. This means that the hollow tubular cooling element provides an insignificant resistance to draw (RTD) level. The term "insignificant RTD level" is used to describe an RTD of less than 1 millimeter of water column per 10 millimeters of the length of the hollow tubular cooling element, preferably less than 0.4 millimeters of water column per 10 millimeters of the length of the hollow tubular cooling element, more preferably less than 0.1 millimeters of water column per 10 millimeters of the length of the hollow tubular cooling element.

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

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

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

[0230] Therefore, the flow channel must be free of any components that would impede the longitudinal flow of air. Preferably, the flow channel is substantially empty, and particularly preferably, the flow channel is empty.

[0231] As will be described in more detail in this disclosure, an aerosol-generating article may comprise a ventilation zone at a location along a downstream section. In some embodiments, the aerosol-generating article may comprise a ventilation zone at a location along a hollow tubular cooling element. This or any ventilation zone may extend through the peripheral wall of the hollow tubular cooling element. Thus, fluid communication is established between the flow channel defined internally by the hollow tubular cooling element and the external environment. The ventilation zone is also described in this 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 can 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] The 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. Providing an empty cavity downstream (preferably immediately downstream) of the aerosol-generating substrate enhances the nucleation of aerosol particles generated by the substrate. Providing a relatively long cavity maximizes these nucleation benefits, thereby improving aerosol formation and cooling.

[0236] The wall thickness of the hollow tubular cooling element can be 100 micrometers to 2 millimeters, or 150 micrometers to 1.5 millimeters, or 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 5 millimeters to 10 millimeters, such as 5.5 millimeters to 9 millimeters, or 6 millimeters to 8 millimeters. In certain embodiments, the hollow tubular element has an outer diameter of less than 7 millimeters.

[0239] The hollow tubular cooling element may have an internal diameter. Preferably, the hollow tubular cooling element has a constant internal diameter along the length of the hollow tubular cooling element. However, the internal 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] Providing a hollow tubular cooling element having an inner diameter as described above can advantageously ensure sufficient rigidity and strength for the hollow tubular cooling element.

[0242] The hollow tubular cooling element may have an inner diameter of no more than 10 millimeters. For example, the hollow tubular cooling element may have an inner diameter of no more than 9 millimeters, no more than 8 millimeters, or no more than 7 millimeters.

[0243] Providing a hollow tubular cooling element having an inner diameter as described above can advantageously reduce the tightening 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 comprise a paper-based material. The hollow tubular cooling element may comprise at least one layer of paper. The paper may be very rigid paper. The paper may be corrugated paper, such as corrugated heat-resistant paper or corrugated parchment paper.

[0247] The hollow tubular cooling element may preferably comprise cardboard. The hollow tubular cooling element may be a cardboard tube. The hollow tubular cooling element may be formed from cardboard. Cardboard is advantageously an economical material that provides a balance between deformability to ensure easy insertion of the article into the aerosol-generating device and sufficient rigidity to ensure proper engagement of the article within the device. Consequently, the cardboard tube can 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 may be a tube formed from spirally wound paper. The hollow tubular cooling element may be formed from multiple layers of paper. The paper may 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 comprise a polymeric material. For example, the hollow tubular cooling element may comprise a polymeric film. The polymeric film may comprise a cellulose film. The hollow tubular cooling element may comprise low-density polyethylene (LDPE) or polyhydroxyalkanoate (PHA) fibers. The hollow tube may comprise cellulose acetate tow.

[0250] If the hollow tubular cooling element contains cellulose acetate tow, the cellulose acetate tow may have a denier value per fiber of 2 to 4 and a total denier value of 25 to 40.

[0251] Preferably, the aerosol-generating article according to the present invention comprises a ventilation zone at a location along a downstream section. In more detail, in those embodiments in which 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 in which the downstream section comprises a downstream hollow tubular element, as described below, the ventilation zone can be provided at a location along the downstream hollow tubular element.

[0252] Thus, a ventilated cavity is provided downstream of the aerosol-generating rod. This offers several potential technical advantages. First, the inventors discovered that a single ventilated hollow tubular cooling element provides particularly efficient aerosol cooling. Second, the inventors unexpectedly discovered that such rapid cooling of volatile compounds released during heating of the aerosol-generating substrate promotes improved nucleation of aerosol particles.

[0253] The ventilation zone may typically comprise a plurality of perforations in the peripheral wall of the hollow tubular cooling element. Preferably, the ventilation zone comprises at least one annular row of perforations. In some embodiments, the ventilation zone may comprise two annular rows of perforations. For example, the perforations may be formed on a production line during the manufacturing process of an aerosol-generating article. Preferably, each annular row of perforations comprises from 8 to 30 perforations.

[0254] The aerosol-generating article according to the present invention may have a ventilation level of at least 40 percent. Increasing the ventilation level may increase the cooling rate of the aerosol. However, increasing the ventilation level may mean that less air is introduced into the aerosol-generating article through the upstream end of the aerosol-generating article, which then flows through the aerosol-generating rod. Thus, 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 has a ventilation level that is less than or equal to 90 percent, more preferably less than or equal to 85 percent, more preferably less than or equal to 80 percent.

[0257] Thus, 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 from 70 percent to 90 percent, preferably from 70 percent to 85 percent, more preferably from 70 percent to 80 percent.

[0258] For example, an aerosol-generating product may have a ventilation rate of approximately 75 percent.

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

[0260] The downstream filter segment may be positioned downstream of the hollow tubular cooling element 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 can also be described as a "smooth" plug, and is non-tubular. Therefore, the filter segment preferably has a substantially uniform cross-section.

[0262] The downstream filter segment is preferably formed from a fibrous filter material. The fibrous filter material can be used to filter an aerosol generated from an 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 comprises a single downstream filter segment. In alternative embodiments, the downstream section comprises two or more downstream filter segments axially aligned end-to-end with one another.

[0264] The downstream filter segment may optionally contain a flavoring agent, which may be provided in any suitable form. For example, the downstream filter segment may contain one or more capsules, beads, or granules of flavoring agent, or one or more threads or fibers filled with a flavoring agent.

[0265] The filter segment preferably located downstream has low particle filtration efficiency.

[0266] A downstream filter segment is preferably surrounded by a filter element. 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 to one or more adjacent upstream components of the aerosol generating article via a rim wrap.

[0268] The downstream filter segment preferably has an outer diameter 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 from 5 millimeters to 10 millimeters, or from 5.5 millimeters to 9 millimeters, or from 6 millimeters to 8 millimeters. In certain embodiments, the outer diameter of the downstream filter segment is less than 7 millimeters.

[0270] Unless otherwise specified, the resistance to draw (RTD) of an aerosol-generating component or article is measured in accordance with ISO 6565-2015. RTD refers to the pressure required to force air through the entire length of the component. The terms “pressure drop” or “resistance to draw” of a component or article may also refer to “resistance to draw”. Such terms generally refer to measurements in accordance with ISO 6565-2015, which are typically performed under test conditions at a volumetric flow rate of 17.5 milliliters per second at the outlet or downstream end of the component being measured, at a temperature of 22 degrees Celsius, a pressure of 101 kPa (approximately 760 Torr), and a relative humidity of 60%. Smoking conditions and smoking machine specifications are set out in ISO 3308 (ISO 3308:2000). Atmospheric conditions for preparation and testing are described in ISO 3402 (ISO 3402:1999).

[0271] The resistance to draw (RTD) of the downstream section may be at least 0 mmH2O. The RTD of the downstream section may be at least 3 mmH2O. The RTD of the downstream section may be at least 6 mmH2O.

[0272] The RTD of the downstream section may not be greater than 12 mmH2O. The RTD of the downstream section may not be greater than 11 mmH2O. The RTD of the downstream section may not be greater than 10 mmH2O.

[0273] The resistance to draw (RTD) characteristics of a downstream section may be completely or largely related 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 can completely determine the RTD of the downstream section.

[0274] The resistance to draw (RTD) of the downstream filter segment may be at least 0 mmH2O, at least 3 mmH2O, or at least 6 mmH2O.

[0275] The RTD of the downstream filter segment may be no more than 12 mmH2O, or no more than 11 mmH2O, or no more than 10 mmH2O.

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

[0277] The downstream filter segment can be formed from a polylactic acid-based material. The downstream filter segment can be formed from a bioplastic material, preferably a starch-based bioplastic material. The downstream filter segment can be formed by injection molding or extrusion. Bioplastic-based materials are advantageous because they can provide downstream filter segment structures that are simple and inexpensive to manufacture with a defined and complex cross-sectional profile, which can contain multiple relatively large airflow channels passing through the downstream filter segment material, which 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 from 5 millimeters to 25 millimeters, or from 10 millimeters to 25 millimeters, or from 5 millimeters to 20 millimeters, or from 10 millimeters to 20 millimeters.

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

[0280] In certain embodiments, the downstream section may comprise a hollow tubular support element located upstream of the hollow tubular cooling element described above. Preferably, the hollow tubular support element is adjacent to the downstream end of the aerosol-generating rod. Preferably, the hollow tubular support element is adjacent to the upstream end of the hollow tubular cooling element. Preferably, the hollow tubular support element and the hollow tubular cooling element are located 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; cardboard; corrugated paper, such as corrugated heat-resistant paper or corrugated parchment 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 member 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, such as 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 of less than 7 millimeters.

[0284] The hollow tubular support member 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 7 millimeters.

[0286] The hollow tubular support member may have a length of less than 15 millimeters. Preferably, the hollow tubular support member has a length of 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 additional 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] Alternatively or in addition to the hollow tubular support element, the downstream section may also comprise a downstream hollow tubular element located downstream of the hollow tubular cooling element. The downstream hollow tubular element may be provided directly 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. If the downstream hollow tubular element extends to the downstream end of the aerosol-generating article, the downstream hollow tubular element may form a cavity at the mouthpiece end of the aerosol-generating article.

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

[0291] The RTD of the downstream hollow tubular member may be less than or equal to 10 millimeters of water column, or less than or equal to 5 millimeters of water column, or less than or equal to 2.5 millimeters of water column, or less than or equal to 2 millimeters of water column. Preferably, the RTD of the downstream hollow tubular member is less than or equal to 1 millimeter of water column.

[0292] The RTD of the downstream hollow tubular member may be at least 0 mmH2O, or at least 0.25 mmH2O, or at least 0.5 mmH2O, or at least 1 mmH2O.

[0293] Therefore, the flow channel of the downstream hollow tubular element must be free of any components that could restrict the longitudinal air flow. 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] The length of the downstream hollow tubular element is preferably less than 20 millimeters, more preferably less than 15 millimeters, more preferably less than 12 millimeters, and 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 comprise a paper-based material. The downstream hollow tubular element may comprise at least one layer of paper. The paper may be very rigid paper. The paper may be corrugated paper, such as corrugated heat-resistant paper or corrugated parchment paper.

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

[0299] The downstream hollow tubular element may be a paper tube. The downstream hollow tubular element may be a tube formed from spirally wound paper. The downstream hollow tubular element may be formed from multiple layers of paper. The paper may 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 comprise a polymeric material. For example, the downstream hollow tubular element may comprise a polymeric film. The polymeric film may comprise a cellulose film. The downstream hollow tubular element may comprise low-density polyethylene (LDPE) or polyhydroxyalkanoate (PHA) fibers. Preferably, the downstream hollow tubular element comprises cellulose acetate tow. For example, in preferred embodiments, the downstream hollow tubular element comprises a hollow acetate tube.

[0301] If the downstream hollow tubular member contains cellulose acetate tow, the cellulose acetate tow may have a denier per fiber of 2 to 4 and a total denier of 25 to 40.

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

[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 instead of a 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 comprise multiple perforations in the peripheral wall of the downstream hollow tubular element. Preferably, the ventilation zone at a location along the downstream hollow tubular element comprises at least one annular row of perforations. In some embodiments, the ventilation zone may comprise two annular rows of perforations. For example, the perforations may be formed on a production line during the manufacturing process of an aerosol-generating article. Preferably, each annular row of perforations comprises from 8 to 30 perforations.

[0305] Aerosol-generating articles according to the present disclosure may also 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] Aerosol-generating articles according to the present invention preferably comprise an upstream element positioned 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 prevent any loss of substrate, which may be advantageous, for example, if the substrate contains particulate plant material.

[0307] If the upstream segment of the aerosol-generating rod contains shredded tobacco, such as cut filler tobacco, the upstream section or element thereof may further help prevent the loss of loose tobacco particles from the upstream end of the product. This may be particularly important, for example, when the shredded tobacco has a relatively low density.

[0308] The upstream element may be a porous element in the form of a plug. Preferably, the upstream element 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 from 50 percent to 90 percent in the longitudinal direction. The porosity of the upstream element in the longitudinal direction is determined by the ratio of the cross-sectional area of ​​the material forming the upstream element and 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 contain a plurality of holes. This can be achieved, for example, by laser perforation. Preferably, the plurality of holes are uniformly distributed across the cross-section of the upstream element.

[0310] The porosity or permeability of an upstream element may be advantageously designed to provide the aerosol generating article with a particular overall resistance to draw (RTD) without substantially affecting the filtration provided by other parts of the article.

[0311] The upstream element may be formed from an air-impermeable material. In such embodiments, the aerosol-generating article may be designed such that air flows into the aerosol-generating rod through suitable ventilation means provided in the wrapper.

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

[0313] The RTD of the upstream element may be less than 30 mmH2O, or less than 20 mmH2O, or less than 10 mmH2O, or less than 5 mmH2O, or less than 2 mmH2O.

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

[0315] The upstream element preferably has an RTD that is less than 2 millimeters of water per millimeter of length, more preferably less than 1.5 millimeters of water per millimeter of length, more preferably less than 1 millimeter of water per millimeter of length, more preferably less than 0.5 millimeters of water per millimeter of length, more preferably less than 0.3 millimeters of water per millimeter of length, more preferably less than 0.2 millimeters of water 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 of water column, more preferably less than 12 millimeters of water column, more preferably less than 10 millimeters of water column.

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

[0318] In other preferred embodiments, the upstream element is formed from a hollow tubular segment defining a longitudinal cavity that provides a channel for unimpeded flow. In such embodiments, the upstream element can provide protection for the aerosol-generating substrate, as described above, while having a minimal impact on the overall resistance to draw (RTD) and filtration properties of the product.

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

[0322] The upstream element is preferably formed from a heat-resistant material. For example, the upstream element is preferably formed from a material that can withstand temperatures no higher than 350 degrees Celsius. This ensures that the upstream element is not adversely affected by the heating means used to heat the aerosol-generating substrate.

[0323] The upstream section or its upstream element preferably 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 from 5 millimeters to 8 millimeters, more preferably from 5.25 millimeters to 7.5 millimeters, more preferably from 5.5 millimeters to 7 millimeters.

[0324] The upstream section or upstream element preferably has a length of 2 millimeters to 10 millimeters, more preferably 3 millimeters to 8 millimeters, 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 filament. The wrapper surrounding the upstream section is preferably a rigid filament, for example, a filament with a basis weight of at least 80 grams per square meter (g / m2) or at least 100 g / m2, or at least 110 g / m2. This provides structural rigidity to the upstream section.

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

[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 less than or equal to 90 millimeters, or less than or equal to 85 millimeters, or less than or equal to 80 millimeters.

[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, 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, 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, even more preferably from 70 millimeters to 80 millimeters. In the 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 approximately 45 millimeters.

[0331] Preferably, the aerosol-generating article has an outer diameter of at least approximately 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 less than or equal to 8 millimeters. More preferably, the aerosol-generating article has an outer diameter of less than or equal to 7.5 millimeters. Even more preferably, the aerosol-generating article has an outer diameter of less than or equal to approximately 7 millimeters.

[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 along the entire length of the article. Alternatively, different sections of the aerosol-generating article may have different outer diameters.

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

[0336] The total RTD of an aerosol-generating product may be no more than 70 millimeters of water column. For example, the total RTD of an aerosol-generating product may be no more than 65 millimeters of water column, no more than 60 millimeters of water column, no more than 55 millimeters of water column, or no more than 50 millimeters of water column.

[0337] The total RTD of an aerosol-generating product may be from 10 millimeters of water to 70 millimeters of water. For example, the total RTD of an aerosol-generating product may be from 20 millimeters of water to 65 millimeters of water, from 30 millimeters of water to 60 millimeters of water, from 35 millimeters of water to 55 millimeters of water, or from 40 millimeters of water to 50 millimeters of water.

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

[0339] In one embodiment, the aerosol-generating rod and mouthpiece element are wrapped separately. The upstream element, aerosol-generating rod, and hollow tubular element are then joined together by an outer wrapper. They are then joined with the downstream filter element, which has its own wrapper, using tipping paper.

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

[0341] The term "hydrophobic" refers to a surface that exhibits water-repellent properties. One common method for determining this property is by measuring the water contact angle. The water contact angle is the angle, typically measured using a liquid, where the liquid / vapor interface meets a solid surface. It quantitatively expresses the wettability of a solid surface by a liquid according to Young's equation. Hydrophobicity, or water contact angle, can be determined using TAPPI Test Method T558, and the result is reported as the contact angle at the interface, expressed in degrees, which can range from approximately zero to approximately 180 degrees.

[0342] In preferred embodiments, the hydrophobic wrapper is a wrapper comprising a paper layer having a water contact angle of about 30 degrees or more, and 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 be surface treated with polyvinyl alcohol 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 the first aspect of the present invention; and an aerosol generating device comprising a heating chamber for accommodating at least a portion 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 placed inside the heating chamber.

[0345] An aerosol-generating device has a distal end and a mouthpiece end. The aerosol-generating device may comprise a housing or casing. The housing or casing of the aerosol-generating device may define a cavity for removably receiving an aerosol-generating article at the mouthpiece end of the device.

[0346] The cavity of the device may be referred to as the heating chamber of the aerosol-generating device. The cavity of the device may extend between the distal end and the mouthpiece, or near end. The distal end of the cavity of the device may be a closed end, and the mouthpiece, or near end of the cavity of the device may be an open end. An aerosol-generating article can be inserted into the cavity of the device, or heating chamber, through the open end of the cavity of the device. The cavity of the device may be cylindrical in shape to match the shape of the aerosol-generating article.

[0347] The term "housed within" may refer to the fact that a component or element is wholly or partially housed within another component or element. For example, the term "an aerosol-generating article housed within a cavity of a device" refers to an aerosol-generating article that is wholly or partially housed within the cavity of the device of the aerosol-generating article. When the aerosol-generating article is housed within the cavity of the device, the aerosol-generating article may abut against the distal end of the cavity of the device. When the aerosol-generating article is housed within the cavity of the device, the aerosol-generating article may be in substantial proximity to the distal end of the cavity of the device. The distal end of the cavity of the device may be defined by an end wall.

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

[0349] The length of the cavity of the device (or heating chamber) may be the same as or greater than the length of the aerosol-generating rod. The length of the cavity of the device may be the same as or greater than the sum of the lengths of the upstream section or element and the aerosol-generating rod. Preferably, the length of the cavity of the device is such that at least 75 percent of the length of the aerosol-generating rod is inserted or positioned within the cavity of the device when the aerosol-generating article is placed in the aerosol-generating device. More preferably, the length of the cavity of the device is such that at least 80 percent of the length of the aerosol-generating rod is inserted or positioned within the cavity of the device when the aerosol-generating article is placed in the aerosol-generating device.More preferably, the length of the device cavity is such that at least 90 percent of the aerosol-generating rod's length is inserted or positioned within the cavity of the device when the aerosol-generating article is positioned within the aerosol-generating device. This maximizes the length of the aerosol-generating rod along which the aerosol-generating substrate can heat up during use, thereby optimizing aerosol release from the aerosol-generating substrate and reducing tobacco waste.

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

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

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

[0353] The diameter of the cavity of the device may be substantially the same as or larger than the diameter of the aerosol-generating article. The diameter of the cavity of the device may be the same as the diameter of the aerosol-generating article to form an interference fit with the aerosol-generating article.

[0354] The cavity of the device may be configured to form an interference fit with an aerosol-generating article located within the cavity of the device. The interference fit may refer to a tight fit. The aerosol-generating device may comprise a peripheral wall. Such a peripheral wall may define the cavity of the device or a heating chamber. The peripheral wall defining the cavity of the device may be configured to engage the aerosol-generating article located within the cavity of the device via an interference fit, such that there is substantially no gap or empty space between the peripheral wall defining the cavity of the device and the aerosol-generating article when it is located within the device.

[0355] Such an interference fit can create a hermetic fit or configuration between the cavity of the device and the aerosol-generating article placed therein.

[0356] With such a sealed configuration, there will be substantially no gap or empty space between the peripheral wall defining the cavity of the device and the aerosol generating article for air to flow therethrough.

[0357] An interference fit with the aerosol generating article may be created along the entire length of the cavity of the device or along a portion of the length of the cavity of the device.

[0358] An aerosol-generating device may comprise an airflow channel extending between an inlet opening of the channel and an outlet opening of the channel. The airflow channel may be configured to create fluid communication between the interior of the cavity of the device and the exterior of the aerosol-generating device. The airflow channel of the aerosol-generating device may be formed within the housing of the aerosol-generating device to provide fluid communication between the interior of the cavity of the device and the exterior of the aerosol-generating device. When the aerosol-generating article is placed within the cavity of the device, the airflow channel may be configured to provide airflow into the article to deliver the generated aerosol to the user, who takes a puff through the mouthpiece end of the article.

[0359] The airflow passage of the aerosol-generating device may be defined within the peripheral wall of the casing of the aerosol-generating device or by this peripheral wall. In other words, the airflow passage of the aerosol-generating device may be defined within the thickness of the peripheral wall, by the inner surface of the peripheral wall, or by a combination of both. The airflow passage may be partially defined by the inner surface of the peripheral wall or may be partially defined within the thickness of the peripheral wall. The inner surface of the peripheral wall defines the peripheral boundary of the cavity of the device.

[0360] The air flow path of the aerosol-generating device may extend from an inlet located at the mouthpiece end or proximal end of the aerosol-generating device to an outlet located away from the mouthpiece end of the device. The air flow path may extend along a direction parallel to the longitudinal axis of the aerosol-generating device.

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

[0362] The heater is preferably located at or around the periphery of the heating chamber.

[0363] Preferably, the heater externally heats the aerosol-generating rod when the aerosol-generating article is placed within the aerosol-generating device. 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-generating article when it is inserted into or placed within the aerosol-generating device.

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

[0365] In some embodiments, the heater is configured to be inserted into the aerosol-generating substrate when the aerosol-generating substrate is positioned within the cavity.

[0366] The heater can be placed inside the cavity of the device or the heating chamber.

[0367] The heater may comprise at least one heating element. The at least one heating element may be any suitable type of heating element. In some embodiments, the device comprises only one heating element. In some embodiments, the device comprises multiple heating elements.

[0368] Suitable materials for forming at least one resistive heating element include, but are not limited to: semiconductors such as doped ceramics, electrically conductive ceramics (such as, for example, molybdenum disilicide), carbon, graphite, metals, metal alloys, and composite materials made from a ceramic material and a metallic material. Such composite materials may comprise doped or undoped ceramics. Examples of suitable doped ceramics include doped silicon carbides. Examples of suitable metals include titanium, zirconium, tantalum, and platinum group metals. Examples of suitable metal alloys include stainless steel, alloys containing nickel, cobalt, chromium, aluminum, titanium, zirconium, hafnium, niobium, molybdenum, tantalum, tungsten, tin, gallium, manganese, and iron, and nickel-based, iron-based, cobalt-based, stainless steel, Timetal ®, and alloys based on iron, manganese and aluminum.

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

[0370] In some embodiments, at least one heating element comprises an electrically insulating substrate, wherein at least one resistive heating element is provided on the electrically insulating substrate.

[0371] The electrically insulating substrate may comprise any suitable material. For example, the electrically insulating substrate may comprise one or more of paper, glass, ceramic, anodized metal, coated metal, and polyimide. Ceramics may include mica, aluminum oxide (Al2O3), or zirconium dioxide (ZrO2). Preferably, the electrically insulating substrate has a thermal conductivity of less than or equal to approximately 40 watts per meter Kelvin, preferably less than or equal to approximately 20 watts per meter Kelvin, and ideally less than or equal to approximately 2 watts per meter Kelvin.

[0372] The heater may comprise a heating element comprising a rigid, electrically insulating substrate with one or more electrically conductive tracks or wires located on its surface. The size and shape of the electrically insulating substrate may allow it to be inserted directly into the aerosol-generating substrate. If the electrically insulating substrate is not sufficiently rigid, the heating element may comprise additional amplifying means. Current may flow through the one or more electrically conductive tracks to heat the heating element and the aerosol-generating substrate.

[0373] In some embodiments, the heater comprises an induction heating device. The induction heating device may comprise an induction coil and a power supply configured to supply a high-frequency oscillating current to the induction coil. In the context of this document, "high-frequency oscillating current" means an oscillating current with a frequency of from approximately 500 kHz to approximately 30 MHz. The heater may advantageously comprise a DC-to-AC converter for converting the DC current supplied by the DC power supply into an AC current. The induction coil may be designed to generate a high-frequency oscillating electromagnetic field upon receiving the high-frequency oscillating current from the power supply. The induction coil may be designed to generate a high-frequency oscillating electromagnetic field in the cavity of the device.In some embodiments, the induction coil may substantially surround the cavity of the device. The induction coil may extend at least partially along the length of the cavity of the device.

[0374] The heater may comprise an induction heating element. The induction heating element may be a susceptor element. The susceptor element may be configured such that, when the aerosol-generating article is placed in the cavity of the aerosol-generating device, the oscillating electromagnetic field generated by the inductor coil induces a current in the susceptor element, resulting in heating of the susceptor element. In these embodiments, the aerosol-generating device is preferably capable of generating a fluctuating electromagnetic field having a magnetic field strength (H-field strength) of 1 to 5 kiloamperes per meter (kA / m), preferably 2 to 3 kA / m, for example, approximately 2.5 kA / m. The electrical aerosol generating device is preferably capable of generating a fluctuating electromagnetic field having a frequency of 1 to 30 MHz, such as 1 to 10 MHz, such as 5 to 7 MHz.

[0375] In these embodiments, the current-receiving element is preferably positioned in contact with the aerosol-generating substrate. In some embodiments, the current-receiving element is positioned in an aerosol-generating device. In these embodiments, the current-receiving element may be positioned in a cavity. The aerosol-generating device may comprise only one current-receiving element. The aerosol-generating device may comprise multiple current-receiving elements. In some embodiments, the current-receiving element is preferably configured to heat the outer surface of the aerosol-generating substrate.

[0376] The current collecting element may comprise any suitable material as described above with respect to the current collecting element included in 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 resistive heating elements and inductive heating elements.

[0378] During use, the heater can be controlled to operate within a specified operating temperature range below the maximum operating temperature. The preferred operating temperature range is from approximately 150 degrees Celsius to approximately 300 degrees Celsius in the heating chamber (or cavity of the device). The heater's operating temperature range can be from approximately 150 degrees Celsius to approximately 250 degrees Celsius.

[0379] The aerosol-generating device may include 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, lithium-iron phosphate, or lithium-polymer battery. However, in some embodiments, the power source may be another type of charge storage device, such as a capacitor. The power source may require recharging and may have a capacity capable of storing sufficient energy for one or more user operations, such as one or more aerosol generation sessions.

[0380] The following is a non-exhaustive list of non-limiting examples. Any one or more features of these examples may be combined with any one or more features of another example, embodiment, or aspect described herein.

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

[0382] Example 2. An 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. An aerosol-generating article according to example 1 or 2, wherein the first aerosol-generating substrate and the second aerosol-generating substrate are aligned end to end.

[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 1-4, 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 differs by an amount within 2 millimeters from the length of the first aerosol-generating segment.

[0388] Example 8. An aerosol-generating article according to any one of examples 1-7, wherein the length of the second aerosol-generating segment differs by an amount 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 1-8, 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 1-8, 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 of examples 1-6 and 10, wherein the length of the second aerosol-generating segment is at least 3 millimeters longer than the length of the first aerosol-generating segment.

[0392] Example 12. An aerosol-generating article according to any one of examples 1-6 and 10-11, wherein the ratio of the length of the first aerosol-generating segment to the length of the second aerosol-generating segment is no more than 1.

[0393] Example 13. An aerosol-generating article according to any one of examples 1-8, 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 of examples 1-6 and 13, wherein the length of the first aerosol-generating segment is at least 3 millimeters longer than the length of the second aerosol-generating segment.

[0395] Example 15. An aerosol-generating article according to any one of examples 1-6 and 13-14, wherein the ratio of the length of the second aerosol-generating segment to the length of the first aerosol-generating segment is no more than 1.

[0396] Example 16. An aerosol-generating article according to any one of examples 1-15, 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 1-16, wherein the first aerosol-generating segment has a length that is less than or equal to 25 millimeters.

[0398] Example 18. An aerosol-generating article according to any one of examples 1-17, 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 1-18, wherein the second aerosol-generating segment has a length that is less than or equal to 25 millimeters.

[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 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 that is less than or equal to 50 millimeters.

[0402] Example 22. An aerosol-generating article according to any one of examples 1-21, wherein 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 0.20.

[0403] Example 23. An aerosol-generating article according to any one of examples 1-22, wherein 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 less than or equal to 0.60.

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

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

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

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

[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 total 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 less than or equal to 0.6.

[0410] Example 30. An aerosol-generating article according to any one of examples 1-29, wherein the density of the second aerosol-generating substrate differs by an amount within 50 mg per cubic centimeter from the density of the first aerosol-generating substrate.

[0411] Example 31. The aerosol-generating article according to any one of Examples 1 to 30, wherein the density of the second aerosol-generating substrate differs by an amount within 10 percent from the density of the first aerosol-generating substrate.

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

[0413] Example 33. An aerosol-generating article according to any one of examples 1-31, 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 1-28 and 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 1-28 and 33-34, wherein the density of the second aerosol-generating substrate is at least 1.2 times greater than the density of the first aerosol-generating substrate.

[0416] Example 36. An aerosol-generating article according to any one of examples 1-31, 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 of examples 1-28 and 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 1-28 and 36-37, wherein the density of the first aerosol-generating substrate is at least 1.2 times greater than the density of the second aerosol-generating substrate.

[0419] Example 39. An aerosol-generating article according to any one of examples 1-38, 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 1-39, wherein the density of the first aerosol-generating substrate is less than or equal to 500 mg per cubic centimeter.

[0421] Example 41. An aerosol-generating article according to any one of examples 1-40, 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 1-41, wherein the density of the second aerosol-generating substrate is less than or equal to 500 mg per cubic centimeter.

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

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

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

[0426] Example 46. The aerosol-generating article according to any one of Examples 1 to 45, wherein the content of the aerosol-forming substance in the second aerosol-generating substrate differs by an amount within 3 percentage points from the content of the aerosol-forming substance in the first aerosol-generating substrate.

[0427] Example 47. The aerosol-generating article according to any one of examples 1 to 46, wherein the content of the aerosol-forming substance in the second aerosol-generating substrate differs by an amount within 10 percentage points from the content of the aerosol-forming substance in the first aerosol-generating substrate.

[0428] Example 48. An aerosol-generating article according to any one of examples 1-47, wherein the content of the aerosol-forming substance in the first aerosol-generating substrate is approximately equal to the content of the aerosol-forming substance in the second aerosol-generating substrate.

[0429] Example 49. An aerosol-generating article according to any one of examples 1-47, wherein the content of the aerosol-forming substance in the second aerosol-generating substrate is higher than the content of the aerosol-forming substance in the first aerosol-generating substrate, based on dry weight.

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

[0431] Example 51. An aerosol-generating article according to any one of examples 1-45 and 49-50, wherein the content of the aerosol-forming substance in the second aerosol-generating substrate is at least 1.2 times greater than the content of the aerosol-forming substance in the first aerosol-generating substrate.

[0432] Example 52. An aerosol-generating article according to any one of examples 1-47, wherein the content of the aerosol-forming substance in the first aerosol-generating substrate is greater than the content of the aerosol-forming substance in the second aerosol-generating substrate, based on dry weight.

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

[0434] Example 54. An aerosol-generating article according to any one of examples 1-47 and 52-53, wherein the content of the aerosol-forming substance in the first aerosol-generating substrate is at least 1.2 times greater than the content of the aerosol-forming substance in the second aerosol-generating substrate.

[0435] Example 55. An aerosol-generating article according to any one of examples 1-54, wherein the first aerosol-generating substrate contains at least 5 percent by weight of an aerosol-forming substance, based on the dry weight of the first aerosol-generating substrate.

[0436] Example 56. An aerosol-generating article according to any one of examples 1-55, wherein the first aerosol-generating substrate contains less than or exactly 80 percent by weight of an aerosol-forming substance, based on the dry weight of the first aerosol-generating substrate.

[0437] Example 57. An aerosol-generating article according to any one of examples 1-56, wherein the second aerosol-generating substrate contains at least 5 percent by weight of an aerosol-forming substance, based on the dry weight of the second aerosol-generating substrate.

[0438] Example 58. An aerosol-generating article according to any one of examples 1-57, wherein the second aerosol-generating substrate contains less than or exactly 80 percent by weight of an aerosol-forming substance, based on the dry weight of the second aerosol-generating substrate.

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

[0440] Example 60. An aerosol-generating article according to any one of examples 1-59, wherein one or both of the first aerosol-generating substrate and the second aerosol-generating substrate comprise cut tobacco filler.

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

[0442] Example 62. An aerosol-generating article according to any one of Examples 1-61, wherein 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 1-62, also comprising one or more elongated current collecting elements within the aerosol generating rod.

[0444] Example 64. An aerosol-generating article according to any one of examples 1-65, wherein the first aerosol-generating substrate is surrounded by a first wrapper, and wherein 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 1-64, further comprising a downstream section provided downstream of the aerosol generating rod.

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

[0447] Example 67. An aerosol generating article according to any one of examples 65 or 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 65-68, wherein the downstream section comprises a ventilation zone.

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

[0451] Example 71. The aerosol-generating article according to any one of examples 1 to 70, wherein the aerosol-generating article has a ventilation level that is less than or equal to 90 percent.

[0452] Example 72. An aerosol generating article according to any one of examples 66-71, 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 any of examples 72-73, 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 66-74, wherein the downstream section also comprises a hollow tubular support element located upstream of the hollow tubular cooling element.

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

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

[0458] Example 77. An aerosol generating article according to any one of examples 1-76, 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 one of examples 1 to 77, wherein the aerosol-generating article has a total 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 1-79 and an aerosol-generating device comprising a heating chamber for accommodating at least a portion 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 placed inside the heating chamber.

[0462] Next, the present invention will be further described with reference to the accompanying drawings, in which:

[0463] Fig. 1 is a schematic side perspective view of an aerosol generating article according to a first embodiment of the first aspect of the present invention;

[0464] Fig. 2 is a schematic side sectional view of the aerosol generating article of Fig. 1;

[0465] Fig. 3 is a schematic side sectional view of an aerosol generating system according to a first embodiment of the second aspect of the present invention, comprising the aerosol generating article shown in Fig. 1 and 2 and an aerosol generating device.

[0466] Fig. 4 is a schematic side sectional view of an aerosol generating article according to a second embodiment of the first aspect of the present invention; and

[0467] Fig. 5 is a schematic side sectional view of an aerosol generating article according to a third embodiment of the first aspect of the present invention.

[0468] The aerosol generating article 10 shown in Fig. 1 comprises an aerosol generating rod 12 and a downstream section 14 at a location downstream of the aerosol generating rod 12. Thus, the aerosol generating article 10 extends from an upstream or distal end 16, which substantially coincides with the upstream end of the rod 12, to a downstream or mouthpiece end 18, which 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.

[0469] The aerosol generating article 10 has a total length of approximately 75 millimeters and an outer diameter of approximately 6.7 mm.

[0470] The aerosol generating rod 12 comprises a first aerosol generating segment 24 and a second aerosol generating segment 26, coaxially aligned with each other. The second aerosol generating article 26 is provided upstream of the first aerosol generating segment 24 and is adjacent to the upstream end of the first aerosol generating segment 24.

[0471] The first aerosol-generating segment 24 has a length of approximately 17 millimeters and contains a first aerosol-generating substrate formed from shredded tobacco material containing approximately 15 percent by weight of glycerin. The density of the first aerosol-generating substrate 24 is approximately 290 mg per cubic centimeter. The first aerosol-generating segment 24 is separately wrapped in a filament (not shown).

[0472] 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 has a length of approximately 17 millimeters and contains a second aerosol-generating substrate formed from shredded tobacco material containing approximately 15 percent by weight of glycerin. The density of the second aerosol-generating substrate 26 is approximately 290 mg per cubic centimeter. The second aerosol-generating segment 26 is separately wrapped in a filament (not shown).

[0473] The total length of the aerosol-generating rod 12 is approximately 34 millimeters. The total length of the downstream section 14 is approximately 41 millimeters.

[0474] The hollow tubular cooling element 20 of the downstream section 14 is positioned immediately downstream of the aerosol generating rod 12, wherein the hollow tubular cooling element 20 is in longitudinal alignment with the rod 12. The upstream end of the hollow tubular cooling element 20 is adjacent to the downstream end of the rod 12.

[0475] 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 affect the overall RTD of the aerosol-generating article. In more detail, the RTD of the hollow tubular cooling element 20 is approximately 0 mm H2O.

[0476] 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, which extends over the entire distance 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 therefore, substantially unlimited air flow along the internal cavity 22 is possible.

[0477] The hollow tubular cooling element 20 has a length of approximately 25 millimeters and an outer diameter of approximately 6.7 millimeters.

[0478] The aerosol-generating article 10 comprises a ventilation zone 30 provided at a location located along the hollow tubular cooling element 20. The ventilation zone 30 comprises an annular row of openings or perforations surrounding the hollow tubular cooling element 20. The perforations of the ventilation zone 30 pass through the wall of the hollow tubular cooling element 20 to allow fluid to enter the internal cavity 22 from outside the article 10. The ventilation level of the aerosol-generating article 10 is approximately 75 percent.

[0479] The downstream filter segment 50 is located immediately downstream of the hollow tubular cooling element 20, wherein the downstream filter segment 50 is in longitudinal alignment with the hollow tubular cooling element 20. The upstream end of the downstream filter segment 50 is adjacent to the downstream end of the hollow tubular cooling element 20.

[0480] The downstream filter segment 50 contains a cylindrical plug made of cellulose acetate tow. The length of the downstream filter segment 50 is approximately 10 mm.

[0481] The downstream hollow tubular element 60 is formed as a hollow cylindrical tube made of cellulose acetate. The downstream hollow tubular element 60 defines an internal cavity that extends the entire distance 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 a mouthpiece end cavity. The internal cavity is substantially empty, and therefore, a substantially unrestricted air flow along the internal cavity is possible.The downstream hollow tubular element 260 has no significant effect on the overall RTD of the aerosol-generating article 10. The length of the downstream hollow tubular element 60 is approximately 6 mm.

[0482] As shown in Fig. 1 and 2, the article 10 comprises an upstream wrapper 44 surrounding the aerosol generating rod 12 and the hollow tubular cooling element 20. The ventilation zone 30 may also comprise an annular row of perforations formed in the upstream wrapper 44. The perforations in the upstream wrapper 44 overlap the perforations provided on the hollow tubular cooling element 20. Accordingly, the upstream wrapper 44 overlaps the perforations of the ventilation zone 30 provided on the hollow tubular cooling element 20.

[0483] The article 10 also includes a rim wrap 52 surrounding the hollow tubular cooling element 20, the mouthpiece element 50, and the downstream hollow tubular element 60. The rim wrap 52 overlaps a portion of the upstream wrap 44 that overlaps the hollow tubular cooling element 20. The rim wrap 52 thus effectively connects the mouthpiece element 50 and the downstream hollow tubular element 60 to the remaining components of the article 10. In addition, the ventilation zone 30 may include an annular row of perforations formed in the rim wrap 52. The perforations in the rim wrap 52 may overlap with perforations provided on the hollow tubular cooling element 20 and the upstream wrap 44.Accordingly, the rim wrap 52 can be applied to the perforation holes of the ventilation zone 30 provided on the hollow tubular cooling element 20 and the wrap 44 located upstream of the flow.

[0484] Fig. 3 shows an aerosol generating system 100 comprising an exemplary aerosol generating device 1 and an aerosol generating article 10 shown in Figs. 1 and 2.

[0485] Fig. 3 shows a downstream section of the mouthpiece end of the aerosol generating device 1, where a cavity of the device is defined and an aerosol generating article 10 can be accommodated. The aerosol generating device 1 comprises a casing (or housing) 4 extending between the mouthpiece end 2 and the distal end (not shown). The casing 4 comprises a peripheral wall 6. The peripheral wall 6 defines a cavity of the device for accommodating the aerosol generating article 10. The cavity of the device is defined by a closed distal end and an open mouthpiece end. The mouthpiece end of the cavity of the device is located on the mouthpiece end of the aerosol generating device 1. The aerosol generating article 10 is configured to be positioned through the mouthpiece end of the cavity of the device and is configured to be adjacent to the closed end of the cavity of the device.

[0486] The air flow channel 5 of the device is defined inside the peripheral wall 6. The air flow channel 5 extends between the inlet opening 7 located at the mouthpiece end of the aerosol generating device 1 and the closed end of the cavity of the device. Air can enter the aerosol generating substrate 12 of the aerosol generating article 10 through an opening (not shown) formed at the closed end of the cavity of the device, providing fluid communication between the air flow channel 5 and the aerosol generating rod 12.

[0487] The aerosol generating device 1 also comprises a heater (not shown) and a power source (not shown) for supplying power to the heater. A controller (not shown) is also provided for controlling such power supply to the heater. The heater is configured to controllably heat the aerosol generating article 10 during use, when the aerosol generating article 1 is placed inside the device 1. The heater is preferably configured to externally heat the aerosol generating rod 12 for optimal aerosol generation. The ventilation zone 30 is arranged to be open when the aerosol generating article 10 is placed inside the aerosol generating device 1.

[0488] In the embodiment shown in Fig. 3, the length of the cavity of the device formed by the peripheral wall 6 is approximately 40 millimeters. When the article 10 is placed inside the cavity of the device, the aerosol generating rod 12 and the upstream portion of the hollow tubular cooling element 20 are placed inside the cavity of the device. The length of such upstream portion of the hollow tubular cooling element 20 is 6 millimeters. Accordingly, approximately 40 millimeters of the article 10 are placed inside the device 1, and approximately 35 millimeters of the article 10 are placed outside the device 1. In other words, approximately 35 millimeters of the article 10 protrudes from the device 1 when the article 10 is placed therein. Such a length of the article 10 protruding from the device 1 is shown in Fig. 3.

[0489] Figure 4 shows a second embodiment of the first aspect of the present invention. The aerosol-generating article 110 shown in Figure 4 has a structure similar to the aerosol-generating article 10 shown in Figures 1 and 2, and differs only in the lengths of the second aerosol-generating substrate 126 and the first aerosol-generating substrate 124.

[0490] 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. The first aerosol-generating substrate has a length of approximately 12 millimeters.

[0491] 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.

[0492] Figure 5 shows a third embodiment of the first aspect of the present invention. The aerosol generating article 210 shown in Figure 5 comprises an aerosol generating rod 212, a downstream section 214 located at a location downstream of the aerosol generating rod 212, and an upstream section 215 located at a location upstream of the aerosol generating rod 212. Thus, the aerosol generating article 210 extends from an upstream or distal end 216, which substantially coincides with the upstream end of the upstream section 215, to a downstream or mouthpiece end 218, which coincides with the downstream end of the downstream section 214.The downstream section 214 comprises a hollow tubular cooling element 220 and a downstream filter segment 250.

[0493] The aerosol generating article 210 has a total length of approximately 45 millimeters and an outer diameter of approximately 7.2 mm.

[0494] The aerosol generating rod 212 comprises a first aerosol generating segment 24 and a second aerosol generating segment 226, coaxially aligned with each other. The second aerosol generating segment 226 is provided upstream of the first aerosol generating segment 224 and is adjacent to the upstream end of the first aerosol generating segment 224.

[0495] The first aerosol-generating segment 24 has a length of approximately 10 millimeters and contains a first aerosol-generating substrate formed from shredded tobacco material containing glycerin in an amount ranging from 10 percent by weight to 20 percent by weight. The density of the first aerosol-generating substrate 224 is approximately 300 mg per cubic centimeter. The first aerosol-generating segment 224 is separately wrapped in a filament (not shown).

[0496] 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 26 has a length of approximately 10 millimeters and contains a second aerosol-generating substrate formed from shredded tobacco material containing from 10 percent by weight to 20 percent by weight of glycerin. The density of the second aerosol-generating substrate 26 is approximately 300 mg per cubic centimeter. The second aerosol-generating segment 26 is separately wrapped in a ficella (not shown).

[0497] The total length of the aerosol-generating rod 212 is approximately 20 millimeters. The total length of the downstream section 214 is approximately 20 millimeters. The total length of the upstream section 215 is approximately 5 millimeters.

[0498] The hollow tubular cooling element 220 of the downstream section 14 is positioned immediately downstream of the aerosol generating rod 12, wherein the hollow tubular cooling element 220 is in longitudinal alignment with the rod 212. The upstream end of the hollow tubular cooling element 20 is adjacent to the downstream end of the rod 212.

[0499] The hollow tubular cooling element 220 defines a hollow section of the aerosol-generating article 210. The hollow tubular cooling element 220 does not substantially affect the overall RTD of the aerosol-generating article. In more detail, the RTD of the hollow tubular cooling element 220 is approximately 0 mm H2O.

[0500] 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 segment 220 defines an internal cavity 222, which extends over the entire distance 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 therefore, substantially unlimited air flow along the internal cavity 222 is possible.

[0501] The hollow tubular cooling element 220 has a length of approximately 13 millimeters, an outer diameter of approximately 7.2 millimeters, and an inner diameter of approximately 6.7 millimeters. Therefore, the thickness of the peripheral wall of the hollow tubular element 220 is approximately 0.25 millimeters.

[0502] The aerosol-generating article 210 comprises a ventilation zone 230 provided at a location located along the hollow tubular cooling element 220. The ventilation zone 230 comprises an annular row of holes or perforations surrounding the hollow tubular cooling element 220. The perforations of the ventilation zone 230 pass through the wall of the hollow tubular cooling element 220 to allow fluid to enter the internal cavity 222 from the outside of the article 210. The ventilation level of the aerosol-generating article 210 is approximately 40 percent.

[0503] The downstream filter segment 250 is positioned immediately downstream of the hollow tubular cooling element 220, and the downstream filter segment 250 is in longitudinal alignment with the hollow tubular cooling element 20. The upstream end of the downstream filter segment 250 is adjacent to the downstream end of the hollow tubular cooling element 220. The downstream end 218 of the aerosol generating article 210 coincides with the downstream end of the downstream filter segment 250.

[0504] The downstream filter segment 250 contains a cylindrical plug made of cellulose acetate tow. The length of the downstream filter segment 250 is approximately 7 mm.

[0505] The upstream section 215 comprises an upstream element 270 positioned immediately upstream of the aerosol generating rod 212, wherein the upstream element 270 is in longitudinal alignment with the rod 212. The downstream end of the upstream element 242 is adjacent to 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 made of cellulose acetate tow or in the form of a hollow cylindrical plug made of cellulose acetate tow having a wall thickness of approximately 1 millimeter.The element 270 located upstream of the flow has a length of approximately 5 millimeters.

[0506] As shown in Fig. 5, the article 210 comprises an upstream wrapper 244 surrounding an upstream element 270, an aerosol generating rod 212, and a hollow tubular cooling element 220. The ventilation zone 230 may also comprise an annular row of perforations formed in the upstream wrapper 244. The perforations in the upstream wrapper 244 overlap with the perforations provided on the hollow tubular cooling element 220. Accordingly, the upstream wrapper 244 overlaps with the perforations of the ventilation zone 230 provided on the hollow tubular cooling element 220.

[0507] The article 210 also includes a rim wrap 252 surrounding the hollow tubular cooling element 220 and the mouthpiece element 250. The rim wrap 252 overlaps a portion of the upstream wrap 244 that overlaps the hollow tubular cooling element 220. In this way, the rim wrap 252 effectively connects the mouthpiece element 250 to the remaining components of the article 210. In addition, the ventilation zone 230 may include an annular row of perforations formed in the rim wrap 252. The perforations of the rim wrap 252 may overlap the perforations provided on the hollow tubular cooling element 220 and in the upstream wrap 244. Accordingly, the rim wrap 252 may overlap to the perforation holes of the ventilation zone 230, provided on the hollow tubular cooling element 220 and in the wrapper 244 located upstream of the flow.

[0508] The specific embodiments and examples described above illustrate, but do not limit, the present invention. It should be understood that other embodiments of the present invention can be realized, and the specific embodiments and examples described herein are not exhaustive.

Claims

1. An aerosol-generating article containing: an aerosol generating rod for producing an inhalable aerosol upon heating; a downstream section provided downstream of the aerosol generating rod and extending to the downstream end of the aerosol generating article; and ventilation zone at a location along the further downstream section; wherein the aerosol generating rod contains: - a first aerosol-generating segment containing a first aerosol-generating substrate, and - a second aerosol-generating segment located upstream of the first aerosol-generating segment and containing a second aerosol-generating substrate; wherein the total combined length of the first aerosol generating segment and the second aerosol generating segment is at least 20 millimeters; wherein 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 less than or equal to 0.6; wherein the aerosol generating product has a ventilation level of at least 40 percent.

2. An aerosol-generating article according to claim 1, wherein the first aerosol-generating substrate contains one or more aerosol-forming substances, and the second aerosol-generating substrate contains one or more aerosol-forming substances, wherein the content of the aerosol-forming substance in the second aerosol-generating substrate differs by an amount within 10 percent from the content of the aerosol-forming substance in the first aerosol-generating substrate.

3. An aerosol-generating article according to claim 1 or 2, wherein the density of the second aerosol-generating substrate differs by an amount within 10 percent of the density of the first aerosol-generating substrate.

4. An aerosol-generating article according to any one of paragraphs 1-3, in which the length of the second aerosol-generating segment differs by an amount within 10 percent of the length of the first aerosol-generating segment.

5. An aerosol generating article according to any one of claims 1 to 4, wherein the downstream section comprises a hollow tubular cooling element.

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

7. An aerosol generating article according to claim 5 or 6, wherein the hollow tubular cooling element has a length of at least 15 millimetres.

8. An aerosol generating article according to any one of claims 5-7, wherein the downstream section comprises a downstream filter segment located downstream of the hollow tubular element, wherein the downstream filter segment is a solid plug.

9. An aerosol generating article according to any one of paragraphs 1-8, having a ventilation level of at least 60 percent.

10. An aerosol generating article according to any one of paragraphs 1-9, having an overall length of at least 60 millimetres.

11. An aerosol-generating article according to any one of claims 1-10, wherein one or both of the first aerosol-generating substrate and the second aerosol-generating substrate comprise shredded tobacco material.

12. An aerosol-generating article according to any one of paragraphs 1-11, wherein one or both of the first aerosol-generating substrate and the second aerosol-generating substrate have a density of less than 400 mg per cubic centimeter.

13. An aerosol-generating article according to any one of paragraphs 1-12, in which each of the first aerosol-generating substrate and the second aerosol-generating substrate contains at least 5 percent by weight of an aerosol-forming substance on a dry weight basis.

14. An aerosol-generating article according to any one of claims 1-13, 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. An aerosol generating system comprising: an aerosol generating article according to any one of paragraphs 1-14; and an aerosol generating device comprising a heating chamber for accommodating at least a portion of an aerosol generating article, and a heater for heating an aerosol generating rod of the aerosol generating article when the aerosol generating article is placed within the heating chamber.

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