Aerosol generation system having a plurality of aerosol generation segments

Abstract

An aerosol generation system is provided that includes an aerosol generator for use with an aerosol generating article. The aerosol generator comprises a heating chamber for receiving the aerosol generating article and a heater assembly disposed along a portion of the heating chamber that defines a heating zone. The aerosol generation system further comprises an aerosol generating article received within the heating chamber of the aerosol generator. The aerosol generating article comprises a first aerosol generating segment that includes a first aerosol generating substrate and a second aerosol generating segment that includes a second aerosol generating substrate. The aerosol generation system is configured such that when the aerosol generating article is fully received within the heating chamber of the aerosol generator, at least 90 percent of the length of the second aerosol generating segment is within the heating zone, the first aerosol generating segment is positioned upstream of the second aerosol generating segment, and the length of the first aerosol generating segment is shorter than the length of the second aerosol generating segment.

Description

Technical Field

[0001] The present invention relates to an aerosol generation system comprising an aerosol generator and an aerosol article. In particular, the present invention relates to an aerosol generation system in which the aerosol generator comprises a first aerosol generation segment and a second aerosol generation segment.

Background Art

[0002] Aerosol generation systems comprising an aerosol generator and a corresponding aerosol article are known in the art. For example, systems are known in which the aerosol article is heated by an aerosol generator to generate an aerosol. The aerosol article may include an aerosol generating substrate such as a tobacco-containing substrate that is heated rather than burned. Typically, in such systems, the aerosol is generated by transfer of heat from a heat source of the aerosol generator to a physically separated aerosol generating substrate or material that is part of the aerosol article. In use, the aerosol generating substrate may be in contact with the aerosol generator, within the aerosol generator, around the aerosol generator, or downstream of the heat source of the aerosol generator. During use of the aerosol generation system, volatile compounds are released from the aerosol generating substrate by heat transfer from the heat source and entrained in the air drawn through the aerosol article. The released compounds condense as they are cooled to form an aerosol.

Summary of the Invention

Problems to be Solved by the Invention

[0003] In a number of prior art documents, an aerosol generating device for consuming an aerosol generating article is disclosed. Such devices include, for example, an electrically heated aerosol generating device in which aerosol is generated by heat transfer from one or more electric heater elements of the aerosol generating device to the aerosol generating substrate of the heated aerosol generating article. For example, an electrically heated aerosol generating device has been proposed that includes an internal heater blade adapted to be inserted into the aerosol generating substrate.

[0004] It is known to provide an aerosol generating system in which an aerosol generating article is configured to be used with a particular aerosol generating device.

[0005] For example, a conventional aerosol generating article may include an upstream element upstream of the aerosol generating substrate. This upstream element may be present to prevent the aerosol generating substrate from falling out of the aerosol generating article and to control the draw resistance of the article. Since the aerosol generating substrate does not extend to the upstream end of the aerosol generating article, it is not necessary to heat the entire length of the aerosol generating article. Accordingly, the corresponding aerosol generating device may include a heater that is positioned and sized to heat only the aerosol generating substrate of the aerosol generating article when the aerosol generating article is fully received within the heating chamber. For example, if the aerosol generating device includes a heating chamber, the heater may not extend to the upstream end of the heating chamber.

[0006] However, providing an aerosol generating device configured to be used only with a particular corresponding aerosol generating article may mean that the device is not very effective when used with other aerosol generating articles. For example, there may be a need to use an aerosol generating device having an aerosol generating article with a larger aerosol generating substrate.

[0007] Accordingly, there is a need for an aerosol generating system that can be effectively used with an alternative aerosol generating article for generating an aerosol and an aerosol generating device. In particular, there is a need for an aerosol generating system that includes an aerosol generating device and an aerosol generating article suitable for heating the aerosol generating substrate of the aerosol generating article to a temperature sufficient for aerosol generation.

Means for Solving the Problem

[0008] According to an aspect of the present disclosure, an aerosol generating system is provided. The aerosol generating system may include an aerosol generating device for use with an aerosol generating article. The aerosol generating device may include a heating chamber for receiving the aerosol generating article. The aerosol generating device may include a heater assembly disposed along a portion of the heating chamber that defines a heating zone. The aerosol generating system may further include an aerosol generating article received within the heating chamber of the aerosol generating device. The aerosol generating article may include a first aerosol generating segment including a first aerosol generating substrate. The aerosol generating article may include a second aerosol generating segment including a second aerosol generating substrate. The aerosol generating system may be configured such that when the aerosol generating article is fully received within the heating chamber of the aerosol generating device, no more than 50 percent of the length of the first aerosol generating segment is within the heating zone. The aerosol generating system may be configured such that when the aerosol generating article is fully received within the heating chamber of the aerosol generating device, at least 90 percent of the length of the second aerosol generating segment is within the heating zone. The first aerosol generating segment may be located upstream of the second aerosol generating segment. The length of the first aerosol generating segment may be less than the length of the second aerosol generating segment.

[0009] According to the present invention, there is provided an aerosol generation system comprising an aerosol generation device for use with an aerosol generation article. The aerosol generation device comprises a heating chamber for receiving the aerosol generation article and a heater assembly disposed along a portion of the heating chamber that defines a heating zone. The aerosol generation device further comprises the aerosol generation article received within the heating chamber of the aerosol generation device. The aerosol generation article comprises a first aerosol generation segment including a first aerosol generation substrate and a second aerosol generation segment including a second aerosol generation substrate. The aerosol generation system is configured such that when the aerosol generation article is fully received within the heating chamber of the aerosol generation device, at least 90 percent of the length of the second aerosol generation segment is within the heating zone, the first aerosol generation segment is positioned upstream of the second aerosol generation segment, and the length of the first aerosol generation segment is shorter than the length of the second aerosol generation segment.

[0010] In other words, when the aerosol generation article is fully received within the heating chamber of the aerosol generation device, most of the second aerosol generation segment is positioned within the heating zone near the heater assembly. This may mean that the second aerosol generation segment receives efficient and direct heating from the heater assembly.

[0011] In contrast, most of the first aerosol generation segment may be positioned outside the heating zone and may be further away from the heater assembly. This may mean that the first aerosol generation segment receives less efficient and indirect heating from the heater assembly. For example, the first aerosol generation segment may be heated by conduction of heat from the second aerosol generation segment.

[0012] In use, this may mean that the second aerosol generating segment is heated to a higher temperature than the first aerosol generating segment. This may also mean that when the heater assembly is activated, the temperature of the second aerosol generating segment rises faster than the temperature of the first aerosol generating segment.

[0013] Thus, by providing a first aerosol generating segment including a first aerosol generating substrate and a second aerosol generating segment including a second aerosol generating substrate, advantageously, the aerosol generating substrates within each aerosol generating segment can be configured to generate aerosol at the temperature reached by each respective aerosol generating segment during use. For example, the first aerosol generating substrate may be configured to generate aerosol at a lower temperature than the second aerosol generating substrate.

[0014] This is advantageous because the entire length of the aerosol generating substrate can be divided into a portion configured to generate aerosol at a lower temperature and a portion configured to generate aerosol at a higher temperature, thereby making it possible to make the entire length of the aerosol generating substrate greater than the length of the heating zone without compromising the efficiency of aerosol generation. This arrangement may also make it possible to increase the total amount of aerosol generating substrate in the aerosol generating article used in an aerosol generating device where the heating zone is shorter than the required total length of the aerosol generating substrate.

[0015] In a preferred embodiment, an aerosol generation system is provided that comprises an aerosol generation device for use with an aerosol generating article. The aerosol generation device comprises a heating chamber for receiving the aerosol generating article and a heater assembly disposed along a portion of the heating chamber that defines a heating zone. The aerosol generation device further comprises the aerosol generating article received within the heating chamber of the aerosol generation device. The aerosol generating article comprises a first aerosol generating segment that includes a first aerosol generating substrate and a second aerosol generating segment that includes a second aerosol generating substrate. The aerosol generation system is configured such that when the aerosol generating article is fully received within the heating chamber of the aerosol generation device, less than 50 percent of the length of the first aerosol generating segment is within the heating zone and at least 90 percent of the length of the second aerosol generating segment is within the heating zone. The first aerosol generating substrate comprises at least one aerosol former wherein the aerosol former content of the first aerosol generating substrate is less than 30 weight percent and a second aerosol generating segment that includes the second aerosol generating substrate and is located upstream of the first aerosol generating segment. The second aerosol generating substrate comprises at least one aerosol former and the aerosol former content of the second aerosol generating substrate is at least 40 weight percent on a dry weight basis.

[0016] In a preferred embodiment, there is provided an aerosol generation system comprising an aerosol generator for use with an aerosol generating article. The aerosol generator comprises a heating chamber for receiving the aerosol generating article and a heater assembly disposed along a portion of the heating chamber defining a heating zone. The aerosol generator further comprises an aerosol generating article received within the heating chamber of the aerosol generator. The aerosol generating article comprises a first aerosol generating segment comprising a first aerosol generating substrate and a second aerosol generating segment comprising a second aerosol generating substrate. The aerosol generation system is configured such that when the aerosol generating article is fully received within the heating chamber of the aerosol generator, at most 50 percent of the length of the first aerosol generating segment is within the heating zone and at least 90 percent of the length of the second aerosol generating segment is within the heating zone. The density of the second aerosol generating substrate is at least 1.2 times the density of the first aerosol generating substrate.

[0017] In a preferred embodiment, an aerosol generation system is provided that comprises an aerosol generation device for use with an aerosol generating article. The aerosol generation device comprises a heating chamber for receiving the aerosol generating article and a heater assembly disposed along a portion of the heating chamber that defines a heating zone. The aerosol generation device further comprises an aerosol generating article received within the heating chamber of the aerosol generation device. The aerosol generating article comprises a first aerosol generating segment that includes a first aerosol generating substrate and a second aerosol generating segment that includes a second aerosol generating substrate. The aerosol generation system is configured such that when the aerosol generating article is fully received within the heating chamber of the aerosol generation device, less than 50 percent of the length of the first aerosol generating segment is within the heating zone and at least 90 percent of the length of the second aerosol generating segment is within the heating zone. The first aerosol generating substrate comprises at least one aerosol former, wherein the aerosol former content of the first aerosol generating substrate is less than 30 weight percent, and a second aerosol generating segment that includes the second aerosol generating substrate and is located upstream of the first aerosol generating segment. The second aerosol generating substrate comprises at least one aerosol former, and the aerosol former content of the second aerosol generating substrate is at least 40 weight percent on a dry weight basis. The density of the second aerosol generating substrate is at least 1.2 times the density of the first aerosol generating substrate.

[0018] In a preferred embodiment, there is provided an aerosol generation system comprising an aerosol generator for use with an aerosol generating article. The aerosol generator comprises a heating chamber for receiving the aerosol generating article and a heater assembly disposed along a portion of the heating chamber that defines a heating zone. The aerosol generator further comprises an aerosol generating article received within the heating chamber of the aerosol generator. The aerosol generating article comprises a first aerosol generating segment including a first aerosol generating substrate and a second aerosol generating segment including a second aerosol generating substrate. The aerosol generation system is configured such that when the aerosol generating article is fully received within the heating chamber of the aerosol generator, less than 50 percent of the length of the first aerosol generating segment is within the heating zone and at least 90 percent of the length of the second aerosol generating segment is within the heating zone. The aerosol forming agent content of the first aerosol generating substrate is less than 30 weight percent and the first aerosol generating substrate has a density of less than 400 mg per cubic centimeter. The second aerosol generating substrate comprises at least one aerosol forming agent, the aerosol forming agent content of the second aerosol generating substrate is at least 40 weight percent on a dry weight basis, and the density of the second aerosol generating substrate is greater than 500 mg per cubic centimeter.

[0019] In a preferred embodiment, there is provided an aerosol generation system comprising an aerosol generation device for use with an aerosol generating article. The aerosol generation device comprises a heating chamber for receiving the aerosol generating article and a heater assembly disposed along a portion of the heating chamber defining a heating zone. The aerosol generation device further comprises an aerosol generating article received within the heating chamber of the aerosol generation device. The aerosol generating article comprises a first aerosol generating segment comprising a first aerosol generating substrate and a second aerosol generating segment comprising a second aerosol generating substrate. The aerosol generation system is configured such that when the aerosol generating article is fully received within the heating chamber of the aerosol generation device, less than 50 percent of the length of the first aerosol generating segment is within the heating zone and at least 90 percent of the length of the second aerosol generating segment is within the heating zone. The first aerosol generating substrate comprises at least one aerosol former and the aerosol former content of the first aerosol generating substrate is less than 30 weight percent. The second aerosol generating substrate comprises at least one aerosol former and the aerosol former content of the second aerosol generating substrate is at least 40 weight percent on a dry weight basis, and the ratio of the length of the first aerosol generating segment to the length of the second aerosol generating segment is 0.5 or less.

[0020] In a preferred embodiment, there is provided an aerosol generation system comprising an aerosol generation device for use with an aerosol generating article. The aerosol generation device comprises a heating chamber for receiving the aerosol generating article and a heater assembly disposed along a portion of the heating chamber that defines a heating zone. The aerosol generation device further comprises an aerosol generating article received within the heating chamber of the aerosol generation device. The aerosol generating article comprises a first aerosol generation segment including a first aerosol generation substrate and a second aerosol generation segment including a second aerosol generation substrate. The aerosol generation system is configured such that when the aerosol generating article is fully received within the heating chamber of the aerosol generation device, no more than 50 percent of the length of the first aerosol generation segment is within the heating zone and at least 90 percent of the length of the second aerosol generation segment is within the heating zone. The first aerosol generation segment has a length of about 5 millimeters. The second aerosol generation segment has a length of about 12 millimeters.

[0021] As used herein with respect to the present invention, the term "heating zone" refers to a portion of the heating chamber that extends in the longitudinal direction between the upstream end and the downstream end of the heater assembly.

[0022] As used herein with respect to the present invention, the term "heater assembly" refers to a component of the aerosol generation device that is involved in heating the aerosol generation substrate of the aerosol generating article. As will be described in more detail below, the heater assembly may directly heat the aerosol generation substrate, which may be the case when the heater assembly includes a resistive heater. The heater assembly may indirectly heat the aerosol generation substrate, which may be the case when the heater assembly comprises an induction coil.

[0023] As used herein with respect to the present invention, the term "longitudinal direction" refers to the direction corresponding to the major axis of the aerosol-generating article or aerosol-generating device, which extends between the upstream end and the downstream end of the aerosol-generating article or aerosol-generating device.

[0024] As used herein with respect to the present invention, the terms "upstream" and "downstream" describe the relative position of an element or portion of an element of the aerosol-generating system with respect to the direction in which aerosol is conveyed through the aerosol-generating article during use. During use, air is drawn longitudinally through the aerosol-generating article.

[0025] As used herein, the term "length" means the dimension of a component of the aerosol-generating system in the longitudinal direction from the most upstream point of that component to the most downstream point of that component. For example, it may be used to mean the dimension of an aerosol-generating substrate or any elongated tubular element in the longitudinal direction.

[0026] The heating chamber of the aerosol-generating device may include an open downstream end and a closed upstream end. In use, the upstream end of the aerosol-generating device may be inserted into the open downstream end of the heating chamber. In use, the upstream end of the aerosol-generating article may abut against the upstream end of the heating chamber. Alternatively, the upstream end of the aerosol-generating article may abut against another component within the heating chamber to prevent the aerosol-generating article from moving further upstream.

[0027] As used herein with respect to the present invention, the term "fully received" refers to the position where the aerosol-generating article is inserted into the heating chamber as far as possible. This can be when the upstream end of the aerosol-generating article abuts the upstream end of the heating chamber. Alternatively, this can be when the upstream end of the aerosol-generating article abuts another component within the heating chamber to prevent the aerosol-generating article from moving further upstream. When the aerosol-generating article is "fully received" within the heating chamber, a portion of the aerosol-generating article may protrude from the open downstream end of the aerosol-generating article. This can be, for example, when the length of the aerosol-generating article is greater than the length of the heating chamber, or when the length of the aerosol-generating article is greater than the distance between the downstream end of the heating chamber and a component within the heating chamber, and where present, may prevent the aerosol-generating article from moving further upstream.

[0028] When the aerosol-generating article is fully received within the heating chamber of the aerosol-generating device, up to 50 percent of the length of the first aerosol-generating segment may be within the heating zone.

[0029] For example, when the aerosol-generating article is fully received within the heating chamber of the aerosol-generating device, up to 50 percent, 40 percent, 30 percent, 20 percent, 10 percent, or 5 percent of the length of the first aerosol-generating segment may be within the heating zone. In some embodiments, when the aerosol-generating article is fully received within the heating chamber of the aerosol-generating device, none of the first aerosol-generating segments are disposed within the heating zone. In other words, the entire length of the first aerosol-generating segment may be disposed outside of the heating zone.

[0030] When the aerosol-generating article is fully received within the heating chamber of the aerosol-generating device, the upstream end of the headline zone may be aligned with the downstream end of the first aerosol-generating segment.

[0031] When the aerosol-generating article is fully received within the heating chamber of the aerosol-generating device, at least 5 percent of the length of the first aerosol-generating segment is within the heating zone.

[0032] For example, when the aerosol-generating article is fully received within the heating chamber of the aerosol-generating device, at least 10 percent, at least 20 percent, at least 30 percent, or at least 40 percent of the length of the first aerosol-generating segment may be within the heating zone.

[0033] When the aerosol-generating article is fully received within the heating chamber of the aerosol-generating device, at least 90 percent of the length of the second aerosol-generating segment may be within the heating zone.

[0034] For example, when the aerosol-generating article is fully received within the heating chamber of the aerosol-generating device, at least 95 percent of the length of the second aerosol-generating segment may be within the heating zone. In some embodiments, when the aerosol-generating article is fully received within the heating chamber of the aerosol-generating device, the entire length of the second aerosol-generating segment may be disposed within the heating zone. In this case, the length of the heating zone is the same as or greater than the length of the second aerosol-generating segment.

[0035] When the aerosol-generating article is fully received within the heating chamber of the aerosol-generating device, the upstream end of the heating zone may be aligned with the upstream end of the second aerosol-generating segment. When the aerosol-generating article is fully received within the heating chamber of the aerosol-generating device, the downstream end of the heating zone may be aligned with the downstream end of the second aerosol-generating segment.

[0036] In some embodiments, when the aerosol-generating article is fully received within the heating chamber of the aerosol-generating device, the upstream end of the second aerosol-generating segment is aligned with the upstream end of the heating zone, the downstream end of the second aerosol-generating segment is aligned with the downstream end of the heating zone, and the first aerosol-generating segment is not disposed within the heating zone at all.

[0037] The first aerosol-generating segment may be located downstream of the second aerosol-generating segment. The first aerosol-generating segment may be located upstream of the second aerosol-generating segment. This is likely to be the case when the aerosol-generating article of the present invention is used with an aerosol-generating device designed for use with different aerosol-generating articles including upstream elements. In this case, the first aerosol-generating segment may replace all or part of the upstream elements within the aerosol-generating article.

[0038] As will be described in more detail below, the aerosol-generating article may further comprise an upstream element.

[0039] Alternatively, the upstream end of the first aerosol-generating segment may define the upstream end of the aerosol-generating article.

[0040] In this case, the aerosol-generating article does not include an upstream element as described above. This may be the case when the aerosol-generating article of the present invention is used with an aerosol-generating device designed for use with different aerosol-generating articles including upstream elements. In this case, the first aerosol-generating segment may replace the upstream element within the aerosol-generating article.

[0041] The upstream end of the second aerosol-generating segment may be in direct contact with the downstream end of the first aerosol-generating segment. Substantially the entire surface of the downstream end of the first aerosol-generating segment may abut against the upstream end of the second aerosol-generating segment.

[0042] This can advantageously improve the heat transfer from the second aerosol generation segment, which is mainly disposed within the heating zone, to the first aerosol generation segment, which is mainly disposed outside the heating zone.

[0043] Alternatively, the upstream end of the second aerosol generation segment may be separated from the downstream end of the first aerosol generation segment.

[0044] The length of the first aerosol generation segment may be less than the length of the second aerosol generation segment.

[0045] This can advantageously mean that a larger proportion of the total aerosol generation substrate is disposed within the heating zone during use. This can advantageously improve the generation of aerosol by the aerosol generation system.

[0046] The ratio of the length of the first aerosol generation segment to the length of the second aerosol generation segment may be 1 or less. The ratio of the length of the first aerosol generation segment to the length of the second aerosol generation segment may be less than 1.

[0047] For example, the ratio of the length of the first aerosol generation segment to the length of the second aerosol generation segment may be 0.8 or less, 0.6 or less, or 0.5 or less.

[0048] The ratio of the length of the first aerosol generation segment to the length of the second aerosol generation segment may be at least 0.1.

[0049] For example, the ratio of the length of the first aerosol generation segment to the length of the second aerosol generation segment may be at least 0.2, at least 0.3, or at least 0.4.

[0050] The ratio of the length of the first aerosol generation segment to the length of the second aerosol generation segment may be 0.1 to 1, 0.2 to 0.8, 0.3 to 0.6, or 0.4 to 0.5.

[0051] The ratio of the length of the first aerosol generation segment to the length of the second aerosol generation segment may be about 0.4, or may be about 0.42.

[0052] In other embodiments, the ratio of the length of the first aerosol generation segment to the length of the second aerosol generation segment may be greater than 1. The ratio of the length of the first aerosol generation segment to the length of the second aerosol generation segment may be about 1.

[0053] The length of the second aerosol generation segment may be at least 3 millimeters greater than the length of the first aerosol generation segment. For example, the second aerosol generation segment may be at least 4 millimeters greater than the length of the first aerosol generation segment, at least 5 millimeters greater, or at least 6 millimeters greater.

[0054] The length of the second aerosol generation segment may be 12 millimeters or less greater than the length of the first aerosol generation segment. For example, the second aerosol generation segment may be 10 millimeters or less greater than the length of the first aerosol generation segment, 9 millimeters or less greater, or 8 millimeters or less greater.

[0055] The length of the second aerosol generation segment may be about 7 millimeters greater than the length of the first aerosol generation segment.

[0056] The first aerosol generation segment may have a length of at least 2 millimeters. For example, the first aerosol generation segment may have a length of at least 3 millimeters, or at least 4 millimeters.

[0057] The first aerosol generation segment may have a length of 8 millimeters or less. For example, the first aerosol generation segment may have a length of 7 millimeters or less, or 6 millimeters or less.

[0058] The first aerosol generation segment may have a length of 2 millimeters to 8 millimeters, 3 millimeters to 7 millimeters, or 4 millimeters to 6 millimeters.

[0059] The first aerosol generation segment may have a length of about 5 millimeters.

[0060] The second aerosol generation segment may have a length of at least 8 millimeters. For example, the second aerosol generation segment may have a length of at least 9 millimeters, or at least 10 millimeters.

[0061] The second aerosol generation segment may have a length of 16 millimeters or less. For example, the second aerosol generation segment may have a length of 15 millimeters or less, or 14 millimeters or less.

[0062] The second aerosol generation segment may have a length of 8 millimeters to 16 millimeters, 9 millimeters to 15 millimeters, or 10 millimeters to 14 millimeters.

[0063] The second aerosol generation segment may have a length of about 12 millimeters.

[0064] The combined length of the first aerosol generation segment and the second aerosol generation segment may be at least 10 millimeters. For example, the combined length of the first aerosol generation segment and the second aerosol generation segment may be at least 12 millimeters, at least 14 millimeters, or at least 16 millimeters.

[0065] The combined length of the first aerosol generation segment and the second aerosol generation segment may be 24 millimeters or less. For example, the combined length of the first aerosol generation segment and the second aerosol generation segment may be 22 millimeters or less, 20 millimeters or less, or 18 millimeters or less.

[0066] The combined length of the first aerosol generation segment and the second aerosol generation segment may be from 10 millimeters to 24 millimeters. For example, the combined length of the first aerosol generation segment and the second aerosol generation segment may be from 12 millimeters to 22 millimeters, from 14 millimeters to 20 millimeters, or from 16 millimeters to 18 millimeters.

[0067] The combined length of the first aerosol generation segment and the second aerosol generation segment may be about 17 millimeters.

[0068] The first aerosol generation segment may have a length of at least 10 millimeters. For example, the first aerosol generation segment may have a length of at least 15 millimeters, or at least 18 millimeters.

[0069] The first aerosol generation segment may have a length of 30 millimeters or less. For example, the first aerosol generation segment may have a length of 25 millimeters or less, or 20 millimeters or less.

[0070] The first aerosol generation segment may have a length of from 10 millimeters to 30 millimeters, from 15 millimeters to 25 millimeters, or from 18 millimeters to 20 millimeters.

[0071] The first aerosol generation segment may have a length of about 18.5 millimeters. The first aerosol generation segment may have a length of about 17 millimeters.

[0072] The second aerosol generation segment may have a length of at least 10 millimeters. For example, the second first aerosol generation segment may have a length of at least 15 millimeters or at least 18 millimeters.

[0073] The second aerosol generation segment may have a length of 30 millimeters or less. For example, the second aerosol generation segment may have a length of 25 millimeters or less, or 20 millimeters or less.

[0074] The second aerosol generation segment may have a length of 10 millimeters to 30 millimeters, 15 millimeters to 25 millimeters, or 18 millimeters to 20 millimeters.

[0075] The second aerosol generation segment may have a length of about 18.5 millimeters. The second aerosol generation segment may have a length of about 17 millimeters.

[0076] The combined length of the first aerosol generation segment and the second aerosol generation segment may be at least 20 millimeters. For example, the combined length of the first aerosol generation segment and the second aerosol generation segment may be at least 25 millimeters, at least 30 millimeters, or at least 35 millimeters.

[0077] The combined length of the first aerosol generation segment and the second aerosol generation segment may be 55 millimeters or less. For example, the combined length of the first aerosol generation segment and the second aerosol generation segment may be 50 millimeters or less, 45 millimeters or less, or 40 millimeters or less.

[0078] The combined length of the first aerosol generating segment and the second aerosol generating segment may be from 20 millimeters to 55 millimeters. For example, the combined length of the first aerosol generating segment and the second aerosol generating segment may be from 25 millimeters to 50 millimeters, from 30 millimeters to 45 millimeters, or from 35 millimeters to 40 millimeters.

[0079] The combined length of the first aerosol generating segment and the second aerosol generating segment may be about 37 millimeters. The combined length of the first aerosol generating segment and the second aerosol generating segment may be about 34 millimeters.

[0080] The first and second aerosol generating segments may have any outer diameter. The first and second aerosol generating segments may have substantially the same outer diameter, and this common diameter may be referred to as the diameter of the aerosol generating segment. One or both of the first and second aerosol generating segments may have an outer diameter that is approximately equal to the outer diameter of the aerosol generating article.

[0081] The "outer diameter" of the aerosol generating segment may be calculated as the average of a plurality of measurements of the diameter of the aerosol generating segment taken at different locations along the length of the aerosol generating segment.

[0082] The aerosol generating segment preferably has an outer diameter of at least about 5 millimeters. More preferably, the aerosol generating segment has an outer diameter of at least about 6 millimeters. Even more preferably, the aerosol generating segment has an outer diameter of at least about 7 millimeters.

[0083] The aerosol generation segment preferably has an outer diameter of about 12 millimeters or less. More preferably, the aerosol generation segment has an outer diameter of about 10 millimeters or less. Even more preferably, the aerosol generation segment has an outer diameter of about 8 millimeters or less.

[0084] Generally, it has been confirmed that the smaller the diameter of the aerosol generation segment, the lower the temperature required to raise the core temperature of the aerosol generation segment, and a sufficient amount of vaporized species is released from the aerosol generation substrate to form a desired amount of aerosol.

[0085] The aerosol generating device may include a main body. The main body or housing of the aerosol generating device may define a heating chamber for removably receiving the aerosol generating article at the downstream end of the device.

[0086] The length of the heating chamber may be from 15 millimeters to 80 millimeters. Preferably, the length of the heating chamber is from 20 millimeters to 70 millimeters. More preferably, the length of the heating chamber is from 25 millimeters to 60 millimeters. Even more preferably, the length of the heating chamber is from 25 millimeters to 50 millimeters.

[0087] The length of the heating chamber may be from 25 millimeters to 29 millimeters. Preferably, the length of the heating chamber is from 25 millimeters to 29 millimeters. More preferably, the length of the heating chamber is from 26 millimeters to 29 millimeters. Even more preferably, the length of the heating chamber is 27 millimeters or 28 millimeters.

[0088] The length of the heating chamber may be the same as or longer than the combined length of the first aerosol generation segment and the second aerosol generation segment. The length of the heating chamber is preferably such that when the aerosol generating article is fully received within the heating chamber, at least 75 percent of the combined length of the first and second aerosol generation segments is inserted or received within the apparatus heating chamber. More preferably, the length of the heating chamber is such that when the aerosol generating article is fully received within the heating chamber, at least 80 percent of the combined length of the first aerosol generation segment and the second aerosol generation segment is inserted or received within the heating chamber. Even more preferably, the length of the heating chamber is such that when the aerosol generating article is fully received within the heating chamber, at least 90 percent of the combined length of the first aerosol generation segment and the second aerosol generation segment is inserted or received within the heating chamber. This maximizes the lengths of the first and second aerosol generation segments that can be heated during use, thereby optimizing aerosol generation from the aerosol generating substrate and reducing waste.

[0089] The length of the heating chamber may be such that when the aerosol generating article is fully received within the heating chamber, a downstream section or a portion thereof is configured to protrude from the heating chamber. The length of the heating chamber may be such that when the aerosol generating article is fully received within the heating chamber, a portion of the downstream section (such as a hollow tubular cooling element or a downstream filter segment) is configured to protrude from the heating chamber. The length of the heating chamber may be such that when the aerosol generating article is fully received within the heating chamber, a portion of the downstream section (such as a hollow tubular cooling element or a downstream filter segment) is configured to be received within the heating chamber.

[0090] At least 25 percent of the length of the downstream section may be inserted or received into the heating chamber when the aerosol-generating article is fully received within the heating chamber. At least 30 percent of the length of the downstream section may be inserted or received into the heating chamber when the aerosol-generating article is fully received within the heating chamber.

[0091] At least 30 percent of the length of the hollow tubular element may be inserted or received into the heating chamber when the aerosol-generating article is fully received within the heating chamber. At least 40 percent of the length of the hollow tubular element may be inserted or received into the heating chamber when the aerosol-generating article is fully received within the heating chamber. At least 50 percent of the length of the hollow tubular element may be inserted or received into the heating chamber when the aerosol-generating article is fully received within the heating chamber. The various lengths of the hollow tubular element are described in more detail within the present disclosure.

[0092] Optimizing the amount or length of the aerosol-generating article inserted into the heating chamber of the aerosol-generating device may increase the resistance to accidental removal of the article during use. In particular, during heating of the aerosol-generating substrate, the substrate may shrink, thereby reducing its outer diameter, which in turn reduces the degree to which the inserted portion of the article inserted into the device can frictionally engage with the heating chamber. The inserted portion of the article, or the portion of the article configured to be received within the heating chamber, may be the same length as the heating chamber.

[0093] The diameter of the heating chamber may be from 4 millimeters to 10 millimeters. The diameter of the heating chamber may be from 5 millimeters to 9 millimeters. The diameter of the heating chamber may be from 6 millimeters to 8 millimeters. The diameter of the heating chamber may be from 6 millimeters to 7 millimeters.

[0094] The diameter of the heating chamber may be substantially the same as or larger than the diameter of the aerosol-generating article. The diameter of the heating chamber may be the same as the diameter of the aerosol-generating article in order to establish a tight fit with the aerosol-generating article.

[0095] The heating chamber may be configured to establish a tight fit with the aerosol-generating article received within the heating chamber. A tight fit may refer to a slip fit. The aerosol-generating device may comprise a peripheral wall. Such a peripheral wall may define the heating chamber. The peripheral wall defining the heating chamber may be configured to engage in a tight fit with the aerosol-generating article received within the heating chamber such that there is substantially no gap or empty space between the peripheral wall defining the heating chamber and the aerosol-generating article when received within the heating chamber.

[0096] Such an airtight fit may establish an airtight fit or configuration between the heating chamber and the aerosol-generating article received therein.

[0097] In such an airtight configuration, there will be substantially no gap or empty space between the peripheral wall defining the heating chamber and the aerosol-generating article through which air can pass and flow.

[0098] The tight fit with the aerosol-generating article may be established along the entire length of the heating chamber or along a portion of the length of the heating chamber.

[0099] The aerosol generating device may comprise an air flow channeling extending between a channel inlet and a channel outlet. The air flow channel may be configured to establish a fluid communication between the interior of the heating chamber and the exterior of the aerosol generating device. The air flow channel of the aerosol generating device may be defined within the housing of the aerosol generating device to enable a fluid communication between the interior of the heating chamber and the exterior of the aerosol generating device. When the aerosol generating article is received within the heating chamber, the air flow channel may be configured to provide air flowing into the article to deliver the generated aerosol to a user who aspirates from the downstream end of the article.

[0100] The air flow channel of the aerosol generating device may be defined within or by the peripheral wall of the housing of the aerosol generating device. In other words, the air flow channel of the aerosol generating device may be defined within the thickness of the peripheral wall, or by the inner surface of the peripheral wall, or by a combination of both. The air flow channel may be partially defined by the inner surface of the peripheral wall and may be partially defined within the thickness of the peripheral wall. The inner surface of the peripheral wall defines the periphery of the heating chamber.

[0101] The air flow channel of the aerosol generating device may extend from an inlet located at the mouth-side end of the aerosol generating device to an outlet located away from the mouth-side end of the device. The air flow channel may extend along a direction parallel to the longitudinal axis of the aerosol generating device.

[0102] The heater assembly may comprise any suitable type of heating element or heater. The heater assembly may comprise at least one resistive heating element and an induction heating assembly. The heater assembly may comprise an external heater or an external heating element.

[0103] The heater assembly may externally heat the aerosol generating article when received within the aerosol generating device. Such an external heater assembly may surround the aerosol generating article when inserted or received within the heating chamber of the aerosol generating device.

[0104] In some embodiments, the heater assembly is arranged to heat at least one outer surface of the aerosol generation substrate. The heater assembly may be positioned within the heating chamber.

[0105] The heater assembly may comprise at least one resistive heating element. The at least one resistive heating element can be any suitable type of resistive heating element. In some embodiments, the heater assembly comprises only one resistive heating element. In some embodiments, the heater assembly comprises a plurality of resistive heating elements. The heater may include at least one resistive heating element. It is preferred that the heater assembly comprises a plurality of resistive heating elements. The resistive heating elements are preferably electrically connected in a parallel arrangement. Advantageously, providing a plurality of resistive heating elements electrically connected in a parallel arrangement can facilitate the delivery of the desired power to the heater while reducing or minimizing the voltage required to provide the desired power. Advantageously, reducing or minimizing the voltage required to operate the heater can facilitate reducing or minimizing the physical size of the power source.

[0106] Suitable materials for forming at least one resistive heating element include, but are not limited to, semiconductors such as doped ceramics, "conductive" ceramics (e.g., molybdenum disilicide, etc.), carbon, graphite, metals, metal alloys, and composite materials made of ceramic materials and metal materials. Such composite materials may include doped ceramics or undoped ceramics. Examples of suitable doped ceramics include doped silicon carbide. Examples of suitable metals include titanium, zirconium, tantalum, and platinum group metals. Examples of suitable metal alloys include stainless steel, nickel-containing, cobalt-containing, chromium-containing, aluminum-containing, titanium-containing, zirconium-containing, hafnium-containing, niobium-containing, molybdenum-containing, tantalum-containing, tungsten-containing, tin-containing, gallium-containing, manganese-containing, and iron-containing alloys, as well as nickel, iron, cobalt, stainless steel-based superalloys, Timetal® (registered trademark), and iron-manganese-aluminum-based alloys.

[0107] In some embodiments, at least one resistive heating element includes one or more stamped portions of an electrically resistive material (such as stainless steel). Alternatively, at least one resistive heating element may include a heating wire or filament (e.g., a wire of Ni—Cr (nickel-chromium), platinum, tungsten, or an alloy).

[0108] In some embodiments, at least one heating element includes an electrically insulated substrate, and at least one resistive heating element is provided on the electrically insulated substrate.

[0109] The electrically insulated substrate can include any suitable material. For example, the electrically insulated substrate can include one or more of paper, glass, ceramic, anodized metal, coated metal, and polymer. The ceramic can include mica, alumina (Al2O3) or zirconia (ZrO2). The polymer can include polyamide. The electrically insulated substrate preferably has a thermal conductivity of about 40 watts per meter kelvin or less, preferably about 20 watts per meter kelvin or less, and ideally about 2 watts per meter kelvin or less.

[0110] When the heater assembly includes a resistive heating element, the resistive heating element may surround at least a portion of the heating chamber and define a heating zone.

[0111] In some embodiments, the heater assembly includes an induction heating assembly. The induction heating assembly may include an inductor coil. The aerosol generating device may include a power source configured to provide a high-frequency oscillating current to the inductor coil. As used herein, a high-frequency oscillating current means an oscillating current having a frequency of about 500 kHz to about 30 MHz. Advantageously, the aerosol generating device may include a DC / AC inverter for converting a DC current supplied by a DC power source into an alternating current. The inductor coil can be arranged to generate a high-frequency oscillating electromagnetic field when receiving the high-frequency oscillating current from the power source. The inductor coil can be arranged to generate a high-frequency oscillating electromagnetic field within the heating chamber. In some embodiments, the inductor coil may substantially surround the heating chamber. The inductor coil can at least partially extend along the length of the heating chamber and define a heating zone.

[0112] The heater assembly may include an induction heating element. The induction heating element may be a susceptor element. As used herein with respect to the present invention, the term "susceptor element" refers to an element that includes a material having the ability to convert electromagnetic energy into heat. When the susceptor element is located within an alternating electromagnetic field, the susceptor is heated. The heating of the susceptor element can be the result of at least one of hysteresis losses and eddy currents induced within the susceptor, depending on the electrical and magnetic properties of the susceptor material.

[0113] The susceptor element can be arranged such that when the aerosol generating article is received within the heating chamber of the aerosol generating device, the oscillating electromagnetic field generated by the inductor coil induces a current within the susceptor element and heats the susceptor element. In these embodiments, it is preferred that the aerosol generating device has the ability to generate a varying electromagnetic field having a magnetic field strength (strength of the H-field) of 1 to 5 kiloamperes per meter (kA / m), preferably 2 to 3 kA / m, for example about 2.5 kA / m. An electrically operating aerosol generating device preferably has the ability to generate a varying electromagnetic field having a frequency of 1 to 30 MHz, for example 1 to 10 MHz, for example 5 to 7 MHz.

[0114] In these embodiments, the susceptor element is preferably located in contact with the aerosol generating substrate. In some embodiments, the susceptor element is located within the aerosol generating device. In these embodiments, the susceptor element can be located within the heating chamber. The aerosol generating device can include only one susceptor element. The aerosol generating device can comprise a plurality of susceptor elements. In some embodiments, the susceptor element is preferably arranged to heat the outer surface of the aerosol generating substrate.

[0115] When the heater assembly comprises both an induction coil and an induction heating element, the heating zone is defined as the axial space between the most upstream portion of the induction claim and the induction heating element, and the axial space between the most downstream portion of the induction claim and the induction heating element.

[0116] The susceptor element can comprise any suitable material. The susceptor element can be formed from any material that can be inductively heated to a temperature sufficient to release the volatile compounds from the aerosol-generating substrate. Suitable materials for an elongate susceptor element include graphite, molybdenum, silicon carbide, stainless steel, niobium, aluminum, nickel, nickel-containing compounds, titanium, and composites of metallic materials. Some susceptor elements contain metal or carbon. Advantageously, the susceptor element can comprise or consist of a ferromagnetic alloy such as, for example, ferromagnetic iron, ferromagnetic steel or stainless steel, ferromagnetic particles, and ferromagnetic materials such as ferrite. A suitable susceptor element may be or may contain aluminum. The susceptor element preferably contains more than about 5 percent of a ferromagnetic or paramagnetic material, more preferably more than 20 percent of a ferromagnetic or paramagnetic material, and even more preferably more than 50 percent or more than 90 percent of a ferromagnetic or paramagnetic material. Some elongate susceptor elements can be heated to a temperature exceeding 250 degrees Celsius.

[0117] The susceptor element can comprise a non-metallic core having a metal layer disposed thereon. For example, the susceptor element can include a metal track formed on the outer surface of a ceramic core or substrate.

[0118] As will be described in more detail below, in some embodiments in which the aerosol-generating device comprises an induction coil, the aerosol-generating article can comprise at least one susceptor element.

[0119] In some embodiments, the aerosol-generating device can comprise at least one resistive heating element and at least one inductive heating assembly. In some embodiments, the aerosol-generating device can comprise a combination of a resistive heating element and an inductive heating assembly.

[0120] The first aerosol-generating substrate has a first density, and the second aerosol-generating substrate has a second density, which may be greater than the first density.

[0121] As used herein with reference to the present invention, the term "density" refers to the bulk density of the first and second aerosol generating substrates. This can be calculated by measuring the total weight of the aerosol generating substrate and dividing this by the volume of the segments of the aerosol generating substrate (excluding the wrapper).

[0122] Advantageously, providing a first aerosol generating substrate having a lower density can provide improved aerosol delivery of the aerosol article. The first aerosol generating substrate having a lower density is heated faster than when it has a higher density due to its lower thermal inertia. This is advantageous because most of the first aerosol generating substrate is not located within the heating zone and is heated to a lower temperature than the second aerosol generating substrate. Providing a lower density for the first aerosol generating substrate can advantageously enable effective aerosol generation in the first aerosol generating substrate despite the indirect heating that most of the aerosol generating substrate would receive. In contrast, the second aerosol generating substrate, which is mainly located within the heating zone, can have a higher density as the second aerosol generating substrate is heated more efficiently. The higher density in the second aerosol generating substrate can advantageously enable sustained aerosol delivery over the entire period of use of the aerosol article.

[0123] Preferably, the first aerosol generating substrate has a density of at least 100 mg per cubic centimeter. More preferably, the density of the first aerosol generating substrate is at least 125 mg per cubic centimeter. More preferably, the density of the first aerosol generating substrate is at least 150 mg per cubic centimeter. Even more preferably, the density of the first aerosol generating substrate is at least 200 mg per cubic centimeter.

[0124] Providing a first aerosol generating substrate having a density of at least 100 mg per cubic centimeter is advantageously such that the first aerosol generating substrate can prevent falling off or otherwise disengaging from the upstream end of the first aerosol generating segment, and the upstream end of the first aerosol generating segment defines the upstream end of the aerosol generating article.

[0125] Preferably, the first aerosol generating substrate has a density of less than 400 mg per cubic centimeter. More preferably, the density of the first aerosol generating substrate is less than 375 mg per cubic centimeter. More preferably, the density of the first aerosol generating substrate is less than 350 mg per cubic centimeter. More preferably, the density of the first aerosol generating substrate is less than 300 mg per cubic centimeter.

[0126] For example, the first aerosol generating substrate may have a density of from 100 mg per cubic centimeter to 400 mg per cubic centimeter, or from 125 mg per cubic centimeter to 375 mg per cubic centimeter, or from 150 mg per cubic centimeter to 350 mg per cubic centimeter, or from 200 mg per cubic centimeter to 300 mg per cubic centimeter.

[0127] Preferably, the second aerosol generating substrate has a density of at least 500 mg per cubic centimeter. More preferably, the density of the second aerosol generating substrate is at least 525 mg per cubic centimeter. More preferably, the density of the second aerosol generating substrate is at least 550 mg per cubic centimeter. Even more preferably, the density of the second aerosol generating substrate is at least 600 mg per cubic centimeter.

[0128] Preferably, the second aerosol generation substrate has a density of less than 1000 mg per cubic centimeter. More preferably, the density of the second aerosol generation substrate is less than 900 mg per cubic centimeter. More preferably, the density of the second aerosol generation substrate is less than 800 mg per cubic centimeter. More preferably, the density of the second aerosol generation substrate is less than 750 mg per cubic centimeter.

[0129] For example, the second aerosol generation substrate may have a density of 500 mg to 1000 mg per cubic centimeter, or 525 mg to 900 mg per cubic centimeter, or 550 mg to 880 mg per cubic centimeter, or 600 mg to 750 mg per cubic centimeter.

[0130] Preferably, the density of the second aerosol generation substrate is at least 25 mg higher per cubic centimeter than the density of the first aerosol generation substrate, or at least 50 mg higher per cubic centimeter than the density of the first aerosol generation substrate, or at least 75 mg higher per cubic centimeter than the density of the first aerosol generation substrate, or at least 100 mg higher per cubic centimeter than the density of the first aerosol generation substrate. More preferably, the density of the second aerosol generation substrate is at least 150 mg higher per cubic centimeter than the density of the first aerosol generation substrate. More preferably, the density of the second aerosol generation substrate is at least 200 mg higher per cubic centimeter than the density of the first aerosol generation substrate. The density of the second aerosol generation substrate may be at most 500 mg higher per cubic centimeter than the density of the first aerosol generation substrate.

[0131] The density of the second aerosol generation substrate is preferably at least 1.05 times, or at least 1.1 times, or at least 1.2 times the density of the first aerosol generation substrate. The density of the second aerosol generation substrate is more preferably at least 1.3 times, or at least 1.4 times, or at least 1.5 times the density of the first aerosol generation substrate. The density of the second aerosol generation substrate is more preferably at least twice the density of the first aerosol generation substrate. The density of the second aerosol generation substrate may be up to 4 times the density of the first aerosol generation substrate.

[0132] In a preferred embodiment of the present invention, the density of the second aerosol generation substrate is at least 1.2 times the density of the first aerosol generation substrate, and the aerosol former content of the second aerosol generation substrate is at least twice the aerosol former content of the first aerosol generation substrate.

[0133] The first aerosol generation substrate and the second aerosol generation substrate may be formed from the same type of substrate as each other. Suitable types of materials for use in the aerosol generating articles of the present invention are described below and include, for example, homogenized tobacco materials such as tobacco cut filler, cast leaf, and aerosol generating films. The first aerosol generation substrate and the second aerosol generation substrate are preferably of different types of materials from each other.

[0134] The first aerosol generation substrate preferably comprises a tobacco material. In a particularly preferred embodiment, the first aerosol generation substrate comprises a shredded tobacco material. For example, the shredded tobacco material may be in the form of cut filler, as will be described in more detail below. Alternatively, the shredded tobacco material may be in the form of a shredded sheet of homogenized tobacco material. Suitable homogenized tobacco materials for use in the present invention are described below.

[0135] In the context of this specification, the term "cut filler" is used to describe a blend of finely cut plant material, such as tobacco plant material, specifically including one or more of the leaf blade, processed stems and veins, and homogenized plant material.

[0136] Cut filler may also include other post-cut materials, filler tobacco, or a wrapper.

[0137] Preferably, the cut filler includes at least 25 percent plant leaf lamina, more preferably at least 50 percent plant leaf lamina, even more preferably at least 75 percent plant leaf lamina, and most preferably at least 90 percent plant leaf lamina. Preferably, the plant material is one of tobacco, mint, tea, and clove. Most preferably, the plant material is tobacco. However, the present invention is equally applicable to other plant materials having the ability to release substances that can form an aerosol upon heating.

[0138] The cut filler preferably includes tobacco plant material including the leaf blade of one or more of bright tobacco, dark tobacco, aromatic tobacco, and filler tobacco. For the purposes of the present invention, the term "tobacco" describes any plant of the genus Nicotiana.

[0139] A cut filler suitable for use in the present invention may generally be similar to cut fillers used in conventional smoking articles. The cut width of the cut filler is preferably from 0.3 millimeters to 2.0 millimeters, more preferably the cut width of the cut filler is from 0.5 millimeters to 1.2 millimeters, and most preferably the cut width of the cut filler is from 0.6 millimeters to 0.9 millimeters. The cut width may play a role in the distribution of heat inside the first aerosol-generating substrate. Also, the cut width may play a role in the draw resistance of the article. Further, overall, the cut width may affect the overall density of the aerosol-generating substrate.

[0140] Since the length of the strands depends on the overall size of the object being cut, the strand lengths of the cut filler are somewhat random values. Nevertheless, by conditioning the material prior to cutting, longer strands can be cut, for example, by controlling the moisture content and overall fineness of the material. Preferably, the strands have a length of from about 10 millimeters to about 40 millimeters, after which the strands are aligned to form a first aerosol generating substrate. Of course, if the strands are disposed within the first aerosol generating substrate with a longitudinal extension of the section less than 40 millimeters in the longitudinal direction, the first aerosol generating substrate may include strands that are on average shorter than the original strand length. It is preferred that the strand lengths of the cut filler are such that from about 20 percent to 60 percent of the strands extend along the entire length of the first aerosol generating segment. This prevents the strands from easily falling out of the first aerosol generating segment.

[0141] In another preferred embodiment, the first aerosol generating substrate comprises a homogenized plant material, preferably a homogenized tobacco material.

[0142] As used herein, the term "homogenized plant material" encompasses any plant material formed by the aggregation of plant particles. For example, a sheet or web of homogenized tobacco material for the aerosol generating substrate of the present invention can be formed by aggregating tobacco material particles obtained by grinding, pulverizing, or subdividing plant material and optionally one or more of tobacco leaf lamina and tobacco leaf stems. The homogenized plant material may be produced by casting, extrusion, a papermaking process, or any other suitable process known in the art.

[0143] The homogenized plant material can be provided in any suitable form.

[0144] In some embodiments, the homogenized plant material may be in the form of one or more sheets. As used herein in the context of the present invention, the term "sheet" describes a thin, layer-like element having a width and length that are significantly greater than its thickness.

[0145] The second aerosol-generating substrate may be in the form of a cut filler or a homogenized tobacco material, as described above.

[0146] The second aerosol-generating substrate is preferably in the form of an aerosol-generating film comprising a cellulosic film-forming agent, nicotine, and an aerosol former. The aerosol-generating film may further comprise a cellulosic thickener. The aerosol-generating film may further comprise water, preferably less than 30 weight percent water.

[0147] As used herein, the term "film" is used to describe a solid, layer-like 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 it can be separated from the support surface even if it is obtained by casting a film-forming formulation onto a support surface. Alternatively, the film may be disposed on a support or sandwiched between other materials. This can enhance the mechanical stability of the film.

[0148] The aerosol former content of the aerosol-generating film is within the range defined for the second aerosol-generating substrate.

[0149] In the context of the present invention, the term "cellulosic film-forming agent" is used to describe a cellulose polymer that has the ability to form a continuous film, either by itself or in the presence of an auxiliary thickener.

[0150] The cellulose-based film-forming agent is preferably selected from the group consisting of hydroxypropyl methylcellulose (HPMC), methylcellulose (MC), ethylcellulose (EC), hydroxyethyl methylcellulose (HEMC), hydroxyethylcellulose (HEC), hydroxypropylcellulose (HPC), and combinations thereof.

[0151] 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.

[0152] In a particularly preferred embodiment, the cellulose-based film-forming agent is HPMC.

[0153] The aerosol-generating film for forming the second aerosol-generating substrate preferably contains at least 10 weight percent of a cellulose-based film-forming agent on a dry weight basis. More preferably, the aerosol-generating film contains at least 15 weight percent of a cellulose-based film-forming agent on a dry weight basis. Even more preferably, the aerosol-generating film contains at least 20 weight percent of a cellulose-based film-forming agent on a dry weight basis.

[0154] Preferably, the aerosol-generating film contains 40 weight percent or less of a cellulose-based film-forming agent on a dry weight basis. More preferably, the aerosol-generating film contains 35 weight percent or less of a cellulose-based film-forming agent on a dry weight basis. Even more preferably, the aerosol-generating film contains 30 weight percent or less of a cellulose-based film-forming agent on a dry weight basis.

[0155] For example, the aerosol-generating film can have a cellulose-based film-forming agent content of 10 weight percent to 40 weight percent, or 15 weight percent to 35 weight percent, or 20 weight percent to 30 weight percent on a dry weight basis.

[0156] The aerosol generating film preferably further contains a cellulose-based strengthening agent. The cellulose-based strengthening agent is preferably selected from the group consisting of cellulose fibers, microcrystalline cellulose (MCC), cellulose powder, and combinations thereof.

[0157] The aerosol generating film preferably contains at least 0.5 weight percent of the cellulose-based strengthening agent based on dry weight. More preferably, the aerosol generating film contains at least 5 weight percent of the cellulose-based strengthening agent based on dry weight. Even more preferably, the aerosol generating film contains at least 10 weight percent of the cellulose-based strengthening agent based on dry weight.

[0158] The aerosol generating film preferably contains 40 weight percent or less of the cellulose-based strengthening agent based on dry weight. More preferably, the aerosol generating film contains 30 weight percent or less of the cellulose-based strengthening agent based on dry weight. Even more preferably, the aerosol generating film contains 25 weight percent or less of the cellulose-based strengthening agent based on dry weight.

[0159] The aerosol generating film may have a cellulose-based strengthening agent content of 0.5 weight percent to 40 weight percent based on dry weight, or 5 weight percent to 30 weight percent based on dry weight, or 10 weight percent to 25 weight percent based on dry weight.

[0160] The aerosol generating film may further contain carboxymethyl cellulose, preferably sodium carboxymethyl cellulose.

[0161] The aerosol generating film may have a carboxymethyl cellulose content of more than about 1 weight percent on a dry weight basis. The aerosol generating film may have a carboxymethyl cellulose content of more than about 2 weight percent on a dry weight basis. The aerosol generating film may have a carboxymethyl cellulose content of more than about 4 weight percent on a dry weight basis.

[0162] The aerosol generating film may have a carboxymethyl cellulose content of less than about 15 weight percent on a dry weight basis. The aerosol generating film may have a carboxymethyl cellulose content of less than about 12 weight percent on a dry weight basis. The aerosol generating film may have a carboxymethyl cellulose content of less than about 10 weight percent on a dry weight basis.

[0163] For example, the aerosol generating film may have a carboxymethyl cellulose content of 1 weight percent to 15 weight percent, or 2 weight percent to 12 weight percent, or 4 weight percent to 10 weight percent on a dry weight basis.

[0164] The aerosol generating film preferably contains nicotine.

[0165] As used herein in connection with the present invention, the term "nicotine" is used to describe nicotine, nicotine base, or nicotine salts. In embodiments where the aerosol generating film contains nicotine base or nicotine salts, the amounts of nicotine recited herein are the amounts of free base nicotine or protonated nicotine, respectively.

[0166] The aerosol generating film may contain natural nicotine or synthetic nicotine.

[0167] The aerosol generating film may contain one or more monobasic nicotine salts.

[0168] As used herein in connection with the present invention, the term "monobasic nicotine salt" is used to describe a nicotine salt of a monobasic acid.

[0169] The aerosol-generating film preferably contains at least 0.5 weight percent of nicotine on a dry weight basis. More preferably, the aerosol-generating film contains at least 1 weight percent of nicotine on a dry weight basis. Even more preferably, the aerosol-generating film contains at least 2 weight percent of nicotine on a dry weight basis. Additionally or alternatively, the aerosol-generating film preferably contains less than 10 weight percent of nicotine on a dry weight basis. More preferably, the aerosol-generating film contains less than 8 weight percent of nicotine on a dry weight basis. Even more preferably, the aerosol-generating film contains less than 6 weight percent of nicotine on a dry weight basis.

[0170] For example, the aerosol-generating film may contain from 0.5 weight percent to 10 weight percent of nicotine, or from 1 weight percent to 8 weight percent of nicotine, or from 2 weight percent to 6 weight percent of nicotine on a dry weight basis.

[0171] The aerosol-generating film may be an aerosol-generating film that is substantially free of tobacco.

[0172] In a preferred embodiment, the aerosol-generating film contains an acid. More preferably, the aerosol-generating film contains one or more organic acids. Even more preferably, the aerosol-generating film contains one or more carboxylic acids. In a particularly preferred embodiment, it is lactic acid, benzoic acid, fumaric acid or levulinic acid.

[0173] The aerosol generating film preferably contains at least about 0.25 weight percent of acid based on dry weight. More preferably, the aerosol generating film contains at least about 0.5 weight percent of acid based on dry weight. Even more preferably, the aerosol generating film contains at least about 1 weight percent of acid based on dry weight. Additionally, or alternatively, the aerosol generating film preferably contains less than about 3.5 weight percent of acid based on dry weight. More preferably, the aerosol generating film contains less than about 3 weight percent of acid based on dry weight. Even more preferably, the aerosol generating film contains less than about 2.5 weight percent of acid based on dry weight.

[0174] For example, the aerosol generating film may contain from 0.25 weight percent to 3.5 weight percent of acid, or from 0.5 weight percent to 3 weight percent of acid, or from 1 weight percent to 2.5 weight percent of acid, based on dry weight.

[0175] The aerosol generating film may have a thickness of from about 0.1 millimeter to about 1 millimeter, more preferably from about 0.1 millimeter to about 0.75 millimeter, even more preferably from about 0.1 millimeter to about 0.5 millimeter. In a particularly preferred embodiment, a layer of the film-forming composition having a thickness of from about 50 micrometers to 400 micrometers, more preferably from about 100 micrometers to 200 micrometers, is formed.

[0176] Optionally, the aerosol generating film may be provided within a second aerosol generating segment on a suitable carrier element.

[0177] In an alternative embodiment of the present invention, the second aerosol generating substrate may comprise a gel composition comprising nicotine, at least one gelling agent, and an aerosol former. The gel composition preferably does not substantially contain tobacco.

[0178] The preferred weight range of nicotine in the gel composition is the same as that defined above in relation to the aerosol generating film.

[0179] The gel composition preferably contains at least 50 weight percent of an aerosol former, more preferably at least 60 weight percent, and still more preferably at least 70 weight percent of the aerosol former, based on dry weight. The gel composition can contain up to 80 weight percent of the aerosol former. The aerosol former in the gel composition is preferably glycerol.

[0180] The gel composition preferably contains at least one gelling agent. The gel composition preferably contains a gelling agent in a total amount in the range of about 0.4 weight percent to about 10 weight percent. More preferably, the composition contains a gelling agent in the range of about 0.5 weight percent to about 8 weight percent. More preferably, the composition contains a gelling agent in the range of about 1 weight percent to about 6 weight percent. More preferably, the composition contains a gelling agent in the range of about 2 weight percent to about 4 weight percent. More preferably, the composition contains a gelling agent in the range of about 2 weight percent to about 3 weight percent.

[0181] The term "gelling agent" refers to a compound that, when added in an amount of about 0.3 weight percent to a homogeneous mixture of 50 weight percent water / 50 weight percent glycerol, forms a solid medium or support matrix and leads to a gel. Examples of gelling agents include, but are not limited to, hydrogen bond cross-linking gelling agents and ionic cross-linking gelling agents.

[0182] The term "hydrogen bond cross-linking gelling agent" refers to a gelling agent that forms non-covalent cross-links or physical cross-links through hydrogen bonds. A hydrogen bond is not a covalent bond to a hydrogen atom, but rather a type of intermolecular electrostatic dipole-dipole attraction. This results from the attraction between a hydrogen atom covalently bonded to an extremely electronegative atom such as an N, O, or F atom and another extremely electronegative atom.

[0183] The hydrogen bond cross-linked gelling agent may include one or more of galactomannan, gelatin, agarose, konjac gum, or agar. The hydrogen bond cross-linked gelling agent may preferably include agar.

[0184] The term "ionic cross-linked gelling agent" refers to a gelling agent that forms a non-covalent cross-linked bond or a physical cross-linked bond through an ionic bond. Ionic cross-linking involves the association of polymer chains by non-covalent interactions. When multivalent molecules with opposite charges are electrostatically attracted to each other, a cross-linked polymer network is formed, and a cross-linked network is formed.

[0185] The ionic cross-linked gelling agent may include low acyl gellan, pectin, kappa carrageenan, iota carrageenan, or alginate. The ionic cross-linked gelling agent may preferably include low acyl gellan.

[0186] The gelling agent may include one or more biopolymers. The biopolymer may be formed of a polysaccharide.

[0187] Examples of biopolymers include, for example, gellan gum (natural gellan gum, low acyl gellan gum, high acyl gellan gum, low acyl gellan gum is preferred), xanthan gum, alginate (alginic acid), agar, guar gum, 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.

[0188] The gel composition may further include a thickening agent. The thickening agent combined with the hydrogen bond cross-linked gelling agent and the ionic cross-linked gelling agent surprisingly supports the solid matrix and maintains the gel composition even when the gel composition contains a high level of glycerol.

[0189] The term "thickener" refers to a compound that, when uniformly added in an amount of 0.3 weight percent to a mixture of 50 weight percent water / 50 weight percent glycerol at 25°C, increases the viscosity without causing gel formation and keeps the mixture in a fluid state or remains fluid. Preferably, the thickener, when uniformly added in an amount of 0.3 weight percent to a mixture of 50 weight percent water / 50 weight percent glycerol at 25°C, increases the viscosity to at least 50 cPs, preferably at least 200 cPs, preferably at least 500 cPs, preferably at least 1000 cPs at a shear rate of 0.1 s-1 without causing gel formation and keeps the mixture in a fluid state or remains fluid. Preferably, the thickener, when homogeneously added in an amount of 0.3 weight percent to a mixture of 50 weight percent water / 50 weight percent glycerol at 25°C, increases the viscosity by at least 2 times, at least 5 times, at least 10 times, or at least 100 times greater than before addition at a shear rate of 0.1 s-1 without causing gel formation and keeps the mixture in a fluid state or remains fluid.

[0190] The viscosity values listed herein can be measured using a Brookfield RVT viscometer with a disk type RV#2 spindle rotating at a speed of 6 revolutions per minute (rpm) at 25°C.

[0191] The gel composition preferably contains a thickener in the range of about 0.2 weight percent to about 5 weight percent. Preferably, the composition contains a thickener in the range of about 0.5 weight percent to about 3 weight percent. Preferably, the composition contains a thickener in the range of about 0.5 weight percent to about 2 weight percent. Preferably, the composition contains a thickener in the range of about 1 weight percent to about 2 weight percent.

[0192] The thickener may contain one or more of xanthan gum, carboxymethyl cellulose, microcrystalline cellulose, methyl cellulose, gum arabic, guar gum, lambda carrageenan, or starch. It is preferable that the thickener contains xanthan gum.

[0193] The gel composition may further contain a divalent cation. Preferably, the divalent cation contains calcium ions such as calcium lactate in the solution. Divalent cations (such as calcium ions) can assist in the gel formation of a composition containing a gelling agent such as an ionic crosslinking gelling agent. The ionic effect may assist in gel formation. The divalent cation may be present in the gel composition in the range of about 0.1 to about 1 weight percent, or about 0.5 weight percent.

[0194] The gel composition may further contain an acid. The acid may contain a carboxylic acid. The carboxylic acid may contain a ketone group. Preferably, the carboxylic acid may contain a ketone group having less than about 10 carbon atoms, or less than about 6 carbon atoms or less than about 4 carbon atoms, such as levulinic acid or lactic acid. Preferably, this carboxylic acid has three carbon atoms (such as lactic acid).

[0195] The gel composition preferably contains some water. When the composition contains some water, the gel composition is more stable. The gel composition preferably contains at least about 1 weight percent, or at least about 2 weight percent, or at least about 5 weight percent of water. The gel composition preferably contains at least about 10 weight percent or at least about 15 weight percent of water.

[0196] The gel composition preferably contains about 8 weight percent to about 32 weight percent of water. The gel composition preferably contains about 15 weight percent to about 25 weight percent of water. The gel composition preferably contains about 18 weight percent to about 22 weight percent of water. The gel composition preferably contains about 20 weight percent of water.

[0197] Preferably, when using a gel composition, the second aerosol generating substrate comprises a porous medium filled with the gel composition. The advantage of a porous medium loaded with the gel composition is that the gel composition is retained within the porous medium, which can assist in the manufacture, storage, or transportation of the gel composition. This can help maintain the desired shape of the gel composition, particularly during manufacture, transportation, or use.

[0198] The term "porous" is used herein to refer to a material that provides a plurality of pores or openings that allow air to pass through the material.

[0199] The porous medium may be any suitable porous material that can hold or retain the gel composition. Ideally, the porous medium can allow the gel composition to move therein. In certain embodiments, the porous medium includes natural materials, synthetic, or semi-synthetic, or combinations thereof. In certain embodiments, the porous medium includes sheet materials, foams, or fibers, such as cotton fibers, or combinations thereof. In certain embodiments, the porous medium includes woven fabrics, non-woven fabrics, or extruded materials, or combinations thereof. The porous medium preferably includes cotton, paper, viscose, PLA, or cellulose acetate, or combinations thereof. The porous medium preferably includes a sheet material, such as cotton or cellulose acetate. In a particularly preferred embodiment, the porous medium includes a sheet made from cotton fibers.

[0200] The porous medium used in the present invention may be crimped or shredded. In a preferred embodiment, the porous medium is crimped. In an alternative embodiment, the porous medium includes shredded porous medium. The crimping or shredding process can be before or after loading the gel composition.

[0201] In certain embodiments, the sheet material is a composite material. The sheet material is preferably porous. The sheet material may assist in the manufacture of a tubular element containing a gel. The sheet material may assist in introducing an active agent into a tubular element containing a gel. The sheet material may serve to stabilize the structure of a tubular element containing a gel. The sheet material may assist in the transport or storage of a gel. Using the sheet material can, for example, enable or assist in adding structure to a porous medium by curling the sheet material.

[0202] The porous medium can be a thread. The thread can include, for example, cotton, paper, or acetate tow. The thread may also be loaded with a gel like any other porous medium. The advantage of using a thread as the porous medium is that it can assist in ease of manufacture.

[0203] The thread may be loaded with a gel by any known means. The thread may simply be coated with a gel, or the thread may be impregnated with a gel. In manufacture, the thread may be impregnated with a gel and stored for immediate use as included in the assembly of a tubular element.

[0204] The porous medium loaded with the gel composition is preferably provided within a tubular element that forms part of an aerosol-generating article. Ideally, the tubular element is longer in the longitudinal direction than in width, but this is not necessarily required as it can be part of a plurality of component items that are longer in their longitudinal direction than in their width. Typically, the tubular element is cylindrical, but this is not necessarily required. For example, the tubular element can have a polygonal shape such as elliptical, triangular, or rectangular, or an irregular cross-section.

[0205] The second aerosol-generating substrate may comprise an aerosol-generating film. The aerosol-generating film may include a cellulose-based film-forming agent, nicotine, and glycerol. The aerosol-generating film may have a glycerol content of at least 40 weight percent.

[0206] The first aerosol generating substrate and the second aerosol generating substrate each comprise at least one aerosol former, and the aerosol former content of the second aerosol generating substrate may be greater than the aerosol former content of the first aerosol generating substrate.

[0207] Providing a lower aerosol former content in the first aerosol generating substrate can advantageously provide improved aerosol delivery of the aerosol generating article. The first aerosol generating substrate having a lower level of aerosol former is heated faster than when it has a higher aerosol former content due to its lower thermal inertia. This is advantageous because most of the first aerosol generating substrate is not located within the heating zone and is heated to a lower temperature than the second aerosol generating substrate. Providing a lower aerosol former content within the first aerosol generating substrate can advantageously enable effective aerosol generation in the first aerosol generating substrate despite the indirect heating that most of the aerosol generating substrate will undergo. In contrast, the second aerosol generating substrate, which is mainly located within the heating zone, may contain a higher aerosol former content as the second aerosol generating substrate is heated more efficiently. The higher aerosol former content in the second aerosol generating substrate can advantageously enable sustained aerosol delivery over the entire period of use of the aerosol generating article.

[0208] Upon volatilization, the aerosol former can carry other vaporized compounds released from the aerosol generating substrate upon heating, such as nicotine and flavorants in the aerosol.

[0209] Aerosol formers suitable for inclusion in the first and second aerosol generating substrates are known in the art and include, but are not limited to, polyhydric alcohols (such as triethylene glycol, propylene glycol, 1,3 - butanediol and glycerol), esters of polyhydric alcohols (glycerol mono -, di - or triacetate), and aliphatic esters of mono -, di - or polycarboxylic acids (such as dimethyl dodecanedioate and dimethyl tetradecanedioate).

[0210] The first and second aerosol generating substrates may contain the same aerosol former (or aerosol formers) as each other, or different aerosol formers may be used.

[0211] The first aerosol generating substrate preferably has an aerosol former content of 30 weight percent or less on a dry weight basis. More preferably, the first aerosol generating substrate has an aerosol former content of 25 weight percent or less on a dry weight basis. Even more preferably, the first aerosol generating substrate has an aerosol former content of 20 weight percent or less on a dry weight basis.

[0212] Preferably, the first aerosol generating substrate has an aerosol former content of at least 5 weight percent on a dry weight basis. More preferably, the first aerosol generating substrate has an aerosol former content of at least 10 weight percent on a dry weight basis. Even more preferably, the first aerosol generating substrate has an aerosol former content of at least 12 weight percent on a dry weight basis. Even more preferably, the first aerosol generating substrate has an aerosol former content of at least 15 weight percent on a dry weight basis.

[0213] For example, the aerosol former content of the first aerosol generating substrate may be from 5 weight percent to 30 weight percent, or from 10 weight percent to 25 weight percent, or from 12 weight percent to 20 weight percent, or from about 15 weight percent to about 20 weight percent on a dry weight basis.

[0214] The first aerosol generation substrate preferably contains glycerol as an aerosol former. For example, the first aerosol generation substrate may contain 5 wt% to 30 wt%, or 10 wt% to 25 wt%, or 12 wt% to 20 wt%, or 15 wt% to 20 wt% of glycerol on a dry weight basis.

[0215] The second aerosol generation substrate preferably has a higher aerosol former content than the first aerosol generation substrate.

[0216] The second aerosol generation substrate preferably has an aerosol former content of at least 40 wt% on a dry weight basis. More preferably, the second aerosol generation substrate has an aerosol former content of at least 45 wt% on a dry weight basis. Even more preferably, the second aerosol generation substrate has an aerosol former content of at least 50 wt% on a dry weight basis.

[0217] The second aerosol generation substrate preferably has an aerosol former content of 80 wt% or less on a dry weight basis. More preferably, the second aerosol generation substrate has an aerosol former content of 75 wt% or less on a dry weight basis. Even more preferably, the second aerosol generation substrate has an aerosol former content of 70 wt% or less on a dry weight basis.

[0218] For example, the aerosol former content of the second aerosol generation substrate may be 40 wt% to 80 wt%, 45 wt% to 75 wt%, or 50 wt% to 70 wt% on a dry weight basis.

[0219] The second aerosol generation substrate preferably contains glycerol as the aerosol former. For example, the second aerosol generation substrate may contain 40 wt% to 80 wt% glycerol, or 45 wt% to 75 wt% glycerol, or 50 wt% to 70 wt% glycerol, or 15 wt% to 20 wt% glycerol on a dry weight basis.

[0220] The aerosol former content of the second aerosol generation substrate is preferably at least 15 percentage points higher than that of the first aerosol generation substrate on a dry weight basis. For example, when the first aerosol generation substrate has an aerosol former content of 10% on a dry weight basis, the second aerosol generation substrate may have an aerosol former content of 25% or more on a dry weight basis.

[0221] More preferably, the aerosol former content of the second aerosol generation substrate is at least 20 percentage points higher than that of the first aerosol generation substrate on a dry weight basis. Even more preferably, the aerosol former content of the second aerosol generation substrate is at least 25 percentage points higher than that of the first aerosol generation substrate on a dry weight basis. The aerosol former content of the second aerosol generation substrate may be at most 60 percentage points higher than that of the first aerosol generation substrate.

[0222] The aerosol former content of the second aerosol - generating substrate is preferably at least 1.2 times the aerosol former content of the first aerosol - generating substrate on a dry weight basis. More preferably, the aerosol former content of the second aerosol - generating substrate is at least 1.5 times the aerosol former content of the first aerosol - generating substrate on a dry weight basis. Even more preferably, the aerosol former content of the second aerosol - generating substrate is at least twice the aerosol former content of the first aerosol - generating substrate on a dry weight basis. The aerosol former content of the second aerosol - generating substrate may be up to 4 times the aerosol former content of the first aerosol - generating substrate.

[0223] In a preferred embodiment of the present invention, the density of the second aerosol - generating substrate is at least 1.2 times the density of the first aerosol - generating substrate, the aerosol former content of the second aerosol - generating substrate is at least twice the aerosol former content of the first aerosol - generating substrate on a dry weight basis, and the ratio of the length of the first aerosol - generating segment to the length of the second aerosol - generating segment is 0.5 or less.

[0224] The aerosol-generating article may further comprise a third aerosol-generating segment comprising a third aerosol-generating substrate downstream of the first aerosol-generating segment and downstream of the second aerosol-generating segment. For example, the aerosol-generating article may comprise a third aerosol-generating segment that abuts the downstream end of the second aerosol-generating segment. Incorporating a third aerosol-generating segment downstream of the second aerosol-generating segment may further enhance aerosol delivery from the aerosol-generating article according to the present invention. When the aerosol-generating article is fully received within the heating chamber of the aerosol-generating device, the entire length of the third aerosol-generating segment may be disposed within the heating zone. When the aerosol-generating article is fully received within the heating chamber of the aerosol-generating device, the third aerosol-generating segment may be disposed only partially within the heating zone. When the aerosol-generating article is fully received within the heating chamber of the aerosol-generating device, the entire length of the third aerosol-generating segment may be disposed outside the heating zone.

[0225] The advantage of providing a third aerosol-generating segment comprising a third aerosol-generating substrate downstream of the first aerosol-generating segment and the second aerosol-generating segment is that it may enable adjustment of the aerosol-generating segment to deliver aerosol during previous puffs of use of the aerosol-generating system. For example, the third aerosol-generating substrate may have a relatively low aerosol former content, or a relatively low density, or both. For example, the third aerosol-generating substrate preferably has an aerosol former content and density within the ranges defined above for the first aerosol-generating substrate. The teachings described above in relation to the first aerosol-generating substrate also apply in relation to the third aerosol-generating substrate.

[0226] As a result, advantageously, the third aerosol generation substrate can be heated more quickly due to its lower thermal inertia and can begin to generate a measurable amount of aerosol within a relatively short time. Since the third aerosol generation segment is located downstream of both the first aerosol generation segment and the second aerosol generation segment, the aerosol generated by the third aerosol generation substrate is efficiently delivered to the user with minimal self-filtration. This further improves the aerosol delivery during previous smoking in the use of the aerosol generation system.

[0227] The third aerosol generation segment can have any length. The third aerosol generation segment may have a length of at least 2 millimeters. For example, the third aerosol generation segment may have a length of at least 3 millimeters, or at least 4 millimeters.

[0228] The third aerosol generation segment may have a length of 8 millimeters or less. For example, the third aerosol generation segment may have a length of 7 millimeters or less, or 6 millimeters or less.

[0229] The third aerosol generation segment may have a length of 2 millimeters to 8 millimeters, 3 millimeters to 7 millimeters, or 4 millimeters to 6 millimeters.

[0230] The third aerosol generation segment may have a length of 1 millimeter to 6 millimeters, 2 millimeters to 5 millimeters, or 3 millimeters to 4 millimeters.

[0231] The third aerosol generation segment may have a length of about 5 millimeters. The third aerosol generation segment may have a length of about 3.5 millimeters.

[0232] In some embodiments, the first, second, and third aerosol generation segments are arranged along the longitudinal axis of the aerosol generating article. The first aerosol generation segment may be arranged most upstream, and the third aerosol generation segment may be arranged most downstream. The second aerosol generation segment may be arranged between the first aerosol generation segment and the third aerosol generation segment. The downstream end of the first aerosol generation segment may abut the upstream end of the second aerosol generation segment. The downstream end of the second aerosol generation segment may abut the upstream end of the third aerosol generation segment.

[0233] The combined length of the first, second, and third aerosol generation segments may be at least 10 millimeters. For example, the combined length of the first, second, and third aerosol generation segments may be at least 12 millimeters, at least 14 millimeters, or at least 16 millimeters.

[0234] The combined length of the first, second, and third aerosol generation segments may be 24 millimeters or less. For example, the combined length of the first, second, and third aerosol generation segments may be 22 millimeters or less, 20 millimeters or less, or 18 millimeters or less.

[0235] The combined length of the first aerosol generation segment, the second aerosol generation segment, and the third aerosol generation segment may be from 10 millimeters to 24 millimeters. For example, the combined length of the first aerosol generation segment, the second aerosol generation segment, and the third aerosol generation segment may be from 12 millimeters to 22 millimeters, from 14 millimeters to 20 millimeters, or from 16 millimeters to 18 millimeters.

[0236] The combined length of the first aerosol generation segment, the second aerosol generation segment, and the third aerosol generation segment may be about 17 millimeters.

[0237] The aerosol generation segment may have an outer diameter substantially equal to the outer diameter of the aerosol generating article.

[0238] The outer diameter of the aerosol generation segment is preferably from 5 millimeters to 12 millimeters, more preferably from 6 millimeters to 10 millimeters, and even more preferably from 7 millimeters to 8 millimeters. In some embodiments, the outer diameter of the aerosol generation segment may be less than 7 millimeters, for example, from 5 millimeters to 7 millimeters, or from 6 millimeters to 7 millimeters.

[0239] The first aerosol generation segment preferably has an outer diameter substantially equal to the outer diameter of the aerosol generating article. The outer diameter of the first aerosol generation segment is preferably substantially constant along the length of the first aerosol generation segment.

[0240] The outer diameter of the first aerosol generation segment is preferably from 5 millimeters to 12 millimeters, more preferably from 6 millimeters to 10 millimeters, and even more preferably from 7 millimeters to 8 millimeters. In some embodiments, the outer diameter of the first aerosol generation segment may be less than 7 millimeters, for example, from 5 millimeters to 7 millimeters, or from 6 millimeters to 7 millimeters.

[0241] The second aerosol generation segment preferably has an outer diameter substantially equal to the outer diameter of the aerosol generating article. The outer diameter of the second aerosol generation segment is preferably substantially constant along the length of the first aerosol generation segment.

[0242] The outer diameter of the second aerosol generation segment is preferably 5 millimeters to 12 millimeters, more preferably 6 millimeters to 10 millimeters, and even more preferably 7 millimeters to 8 millimeters. In some embodiments, the outer diameter of the second aerosol generation segment may be less than 7 millimeters, for example, 5 millimeters to 7 millimeters, or 6 millimeters to 7 millimeters.

[0243] The third aerosol generation segment preferably has an outer diameter substantially equal to the outer diameter of the aerosol generating article. The outer diameter of the third aerosol generation segment is preferably substantially constant along the length of the third aerosol generation segment.

[0244] Preferably, the outer diameter of the third aerosol generation segment is 5 millimeters to 12 millimeters, more preferably 6 millimeters to 10 millimeters, and even more preferably 7 millimeters to 8 millimeters. In some embodiments, the outer diameter of the third aerosol generation segment may be less than 7 millimeters, for example, 5 millimeters to 7 millimeters, or 6 millimeters to 7 millimeters.

[0245] The first aerosol generation segment, the second aerosol generation segment, and the third aerosol generation segment (if present) preferably have substantially the same outer diameter as each other.

[0246] The average cross-sectional area of the first aerosol generation segment is preferably at least 50 percent of the average cross-sectional area of the aerosol generating article, more preferably at least 80 percent of the average cross-sectional area of the aerosol generating article, and even more preferably at least 90 percent of the average cross-sectional area of the aerosol generating article.

[0247] The cross-sectional area of the first aerosol generation segment at its upstream end is preferably at least 50 percent of the average cross-sectional area of the aerosol generating article, more preferably at least 80 percent of the average cross-sectional area of the aerosol generating article, and even more preferably at least 90 percent of the average cross-sectional area of the aerosol generating article.

[0248] The average cross-sectional area of the second aerosol generation segment is preferably at least 50 percent of the average cross-sectional area of the aerosol generating article, more preferably at least 80 percent of the average cross-sectional area of the aerosol generating article, and even more preferably at least 90 percent of the average cross-sectional area of the aerosol generating article.

[0249] The cross-sectional area of the second aerosol generation segment at its downstream end is preferably at least 50 percent of the average cross-sectional area of the aerosol generating article, more preferably at least 80 percent of the average cross-sectional area of the aerosol generating article, and even more preferably at least 90 percent of the average cross-sectional area of the aerosol generating article.

[0250] The cross-sectional area of the first aerosol generation segment at its upstream end is substantially the same as the cross-sectional area of the second aerosol generation segment at its downstream end.

[0251] The aerosol-generating article of the present invention preferably comprises an upstream element which is located upstream of and adjacent to the first aerosol-generating segment. The upstream element advantageously prevents direct physical contact with the upstream end of the aerosol-generating segment. For example, if the aerosol-generating substrate comprises a susceptor element, the upstream element may prevent direct physical contact with the upstream end of the susceptor element. This helps to prevent displacement or deformation of the susceptor element during handling or transportation of the aerosol-generating article. As a result, this helps to fix the shape and position of the susceptor element. Furthermore, the presence of the upstream element helps to prevent any loss of the substrate, which may be advantageous, for example, when the substrate contains particulate plant material.

[0252] If the first aerosol-generating segment comprises shredded tobacco such as tobacco cut filler, the upstream section or its element may additionally help to prevent loss of powdered particles of tobacco from the upstream end of the article. This can be particularly important, for example, when the density of the shredded tobacco is relatively low.

[0253] The upstream section or its upstream element may also provide some additional protection to the aerosol-generating substrate during storage, in order to at least partly cover the upstream end of the aerosol-generating substrate which would otherwise be exposed.

[0254] In the case of an aerosol-generating article intended to be inserted into a heating chamber in an aerosol-generating device so that the aerosol-generating substrate can be externally heated within the heating chamber, the upstream section or its upstream element may advantageously facilitate the insertion of the upstream end of the article into the heating chamber. Incorporating the upstream element may additionally protect the end of the first aerosol-generating segment during insertion of the article into the heating chamber, thereby minimizing the risk of damage to the substrate.

[0255] The upstream element may be a porous plug element. The upstream element preferably has a porosity of at least 50 percent in the longitudinal axis direction of the aerosol generating article. More preferably, the upstream element has a porosity of 50 percent to 90 percent in the longitudinal axis direction. The porosity of the upstream element in the longitudinal axis direction is defined by the ratio of the cross-sectional area of the material forming the upstream element to the internal cross-sectional area of the aerosol generating article at the position of the upstream element.

[0256] The upstream element may be made of a porous material or may comprise a plurality of openings. This can be achieved, for example, by laser drilling. The plurality of openings are preferably uniformly dispersed across the cross-section of the upstream element.

[0257] Advantageously, the porosity or permeability of the upstream element may be designed to provide an aerosol generating article having a specific overall draw resistance (RTD) that does not substantially affect the filtration provided by other parts of the article.

[0258] The upstream element may be formed from a material that is impermeable to air. In such embodiments, the aerosol generating article may be configured such that air flows into at least one of the first aerosol generating segment and the second aerosol generating segment via suitable ventilation means provided within the wrapper.

[0259] In certain preferred embodiments of the present invention, it may be desirable to minimize the RTD of the upstream element. For example, this may apply to articles intended to be inserted into the heating chamber of an aerosol generating device such that the aerosol generating substrate is externally heated, as described herein. In the case of such articles, it is desirable to provide the article with as low an RTD as possible such that most of the RTD experience by the consumer is provided by the aerosol generating device rather than the article.

[0260] The overall RTD of the aerosol-generating article may be at least 10 millimeters of H2O. For example, the overall RTD of the aerosol-generating article may be at least 20 millimeters of H2O, at least 30 millimeters of H2O, at least 35 millimeters of H2O, or at least 40 millimeters of H2O.

[0261] The overall RTD of the aerosol-generating article may be 70 millimeters of H2O or less. For example, the overall RTD of the aerosol-generating article may be 60 millimeters of H2O or less, 55 millimeters of H2O or less, 50 millimeters of H2O or less, or 45 millimeters of H2O or less.

[0262] The overall RTD of the aerosol-generating article may be from 10 millimeters of H2O to 70 millimeters of H2O. For example, the overall RTD of the aerosol-generating article may be from 20 millimeters of H2O to 60 millimeters of H2O, from 30 millimeters of H2O to 55 millimeters of H2O, from 35 millimeters of H2O to 50 millimeters of H2O, or from 40 millimeters of H2O to 45 millimeters of H2O.

[0263] The overall RTD of the aerosol-generating article may be from 40 millimeters of H2O to 60 millimeters of H2O, from 35 millimeters of H2O to 40 millimeters of H2O, from 45 millimeters of H2O to 50 millimeters of H2O, or from 55 millimeters of H2O to 65 millimeters of H2O.

[0264] The overall RTD of the aerosol-generating article may be about 38 millimeters of H2O, about 48 millimeters of H2O, or about 60 millimeters of H2O.

[0265] The aerosol-generating article according to the present invention preferably further comprises a downstream section located downstream of the first aerosol-generating segment, the second aerosol-generating segment, and, if present, the third aerosol-generating segment. The downstream section is preferably located immediately downstream of the second aerosol-generating segment, or, if present, the third aerosol-generating segment. The downstream section of the aerosol-generating article preferably extends between the second aerosol-generating segments, or, if present, between the third aerosol-generating segment and the downstream end of the aerosol-generating article. The downstream section may comprise one or more elements, each of which is described in more detail within the present disclosure.

[0266] The length of the downstream section may be at least 20 millimeters. The length of the downstream section may be at least 25 millimeters. The length of the downstream section may be at least 30 millimeters.

[0267] The length of the downstream section may be less than 70 millimeters. The length of the downstream section may be 60 millimeters or less. The length of the downstream section may be 50 millimeters or less.

[0268] 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.

[0269] Providing a relatively long downstream section ensures that the appropriate length of the aerosol-generating article protrudes from the aerosol-generating device when the article is received within the aerosol-generating device. Such an appropriate protrusion length facilitates the ease of insertion and extraction of the article from the device, which also ensures that the upstream portion of the article is properly inserted into the device, particularly reducing the risk of damage during insertion.

[0270] The ratio between the length of the downstream section and the total length of the aerosol-generating article may be less than 0.80. More preferably, the ratio between the length of the downstream section and the total length of the aerosol-generating article may be less than 0.75. Even more preferably, the ratio between the length of the downstream section and the total length of the aerosol-generating article may be less than 0.70.

[0271] The ratio between the length of the downstream section and the total length of the aerosol-generating article may be at least 0.30. Preferably, the ratio between the length of the downstream section and the total length of the aerosol-generating article may be at least 0.40. More preferably, the ratio between the length of the downstream section and the total length of the aerosol-generating article may be at least 0.50.

[0272] In some embodiments, the ratio between the length of the downstream section and the total length of the aerosol-generating article is from 0.30 to 0.80, preferably from 0.40 to 0.75, more preferably from 0.50 to 0.70.

[0273] The downstream section of the aerosol-generating article according to the present invention preferably comprises a hollow tubular cooling element provided downstream of the second aerosol-generating segment, or, if present, the third aerosol-generating segment. The hollow tubular cooling element may advantageously provide an aerosol cooling element for the aerosol-generating article.

[0274] The hollow tubular cooling element may be provided immediately downstream of the second aerosol-generating segment, or, if present, the third aerosol-generating segment. In other words, the hollow tubular cooling element may abut the downstream end of the second aerosol-generating segment, or, if present, the third aerosol-generating segment. The hollow tubular cooling element may define the upstream end of the downstream section of the aerosol-generating article. The downstream end of the aerosol-generating article may coincide with the downstream end of the downstream section. In some embodiments, the downstream section of the aerosol-generating article comprises a single hollow tubular element. In other words, the downstream section of the aerosol-generating article may comprise only one hollow tubular element. In other embodiments, the downstream section comprises two or more hollow tubular elements as described below.

[0275] As used throughout this disclosure, the term "hollow tubular element" generally means an elongated element that defines a lumen or air flow path along its longitudinal axis. In particular, the term "tubular" is used herein with respect to a tubular element having a substantially cylindrical cross-section and defining at least one air flow conduit that establishes unbroken fluid communication between the upstream end of the tubular element and the downstream end of the tubular element. However, of course, alternative shapes (e.g., alternative cross-sectional shapes) of the tubular element may be possible.

[0276] In the context of the present invention, the hollow tubular cooling element provides a flow channel with negligible resistance. This means that the hollow tubular cooling element provides a negligible level of draw resistance (RTD). The term "negligible level of RTD" is used to describe an RTD of less than 1 millimeter of H2O per 10 millimeters of the length of the hollow tubular cooling element, preferably less than 0.4 millimeter of H2O per 10 millimeters of the length of the hollow tubular cooling element, more preferably less than 0.1 millimeter of H2O per 10 millimeters of the length of the hollow tubular cooling element.

[0277] The RTD of the hollow tubular cooling element is preferably 10 millimeters H2O or less. More preferably, the RTD of the hollow tubular cooling element is 5 millimeters H2O or less. Even more preferably, the RTD of the hollow tubular cooling element is 2.5 millimeters H2O or less. Even more preferably, the RTD of the hollow tubular cooling element is 2 millimeters H2O or less. Even more preferably, the RTD of the hollow tubular cooling element is 1 millimeter H2O or less.

[0278] The RTD of the hollow tubular cooling element can be at least 0 millimeters H2O, or at least 0.25 millimeters H2O, or at least 0.5 millimeters H2O, or at least 1 millimeter H2O.

[0279] In the aerosol-generating article according to the present invention, the overall RTD of the article essentially depends on the RTD of the aerosol-generating segment and optionally the RTD of downstream and / or upstream elements. This is because the hollow tubular cooling element is substantially empty and thus contributes only substantially marginally to the overall RTD of the aerosol-generating article.

[0280] Therefore, the flow channel should not include any components that would impede the flow of air in the longitudinal axis direction. Preferably, the flow channel is substantially empty, and particularly preferably, the flow channel is empty.

[0281] As described in more detail within the present disclosure, the aerosol-generating article may comprise a ventilation zone at a location along the downstream section. In some embodiments, the aerosol-generating article may comprise a ventilation zone at a location along the hollow tubular cooling element. Such, or any ventilation zone, may extend through the peripheral wall of the hollow tubular cooling element. In this way, fluid communication is established between the flow channel internally defined by the hollow tubular cooling element and the external environment. The ventilation zone is further described within the present disclosure.

[0282] The length of the hollow tubular cooling element is preferably at least 15 millimeters. More preferably, the length of the hollow tubular cooling element is at least 20 millimeters. The length of the hollow tubular cooling element may be at least 25 millimeters. More preferably, the length of the hollow tubular cooling element is at least 30 millimeters.

[0283] The length of the hollow tubular cooling element is preferably less than 50 millimeters. More preferably, the length of the hollow tubular cooling element is less than 45 millimeters. Even more preferably, the length of the hollow tubular cooling element is less than 40 millimeters.

[0284] A relatively long hollow tubular cooling element provides and defines a relatively long internal cavity within the aerosol generating article and downstream of the second aerosol generating segment, or the third aerosol generating segment if present. As contemplated by the present disclosure, providing an empty cavity downstream (preferably immediately downstream) of the aerosol generating substrate enhances the nucleation of aerosol particles generated by the substrate. Providing a relatively long cavity maximizes the advantages of such nucleation, thereby improving aerosol formation and cooling.

[0285] The thickness of the peripheral wall (in other words, the wall thickness) of the hollow tubular cooling element may be at least 100 micrometers. The wall thickness of the hollow tubular cooling element may be at least 150 micrometers. The wall thickness of the hollow tubular cooling element may be at least 200 micrometers, preferably at least 250 micrometers, and even more preferably at least 500 micrometers (or 0.5 millimeter).

[0286] The wall thickness of the hollow tubular cooling element may be 2 millimeters or less, preferably 1.5 millimeters or less, and even more preferably 1.25 millimeters or less. The wall thickness of the hollow tubular cooling element may be 1 millimeter or less. The wall thickness of the hollow tubular cooling element may be 500 micrometers or less.

[0287] The wall thickness of the hollow tubular cooling element may be from 100 micrometers to 2 millimeters, preferably from 150 micrometers to 1.5 millimeters, and even more preferably from 200 micrometers to 1.25 millimeters.

[0288] The wall thickness of the hollow tubular cooling element may preferably be 250 micrometers (0.25 millimeters).

[0289] At the same time, keeping the thickness of the peripheral wall of the hollow tubular cooling element relatively low ensures that the overall internal volume of the hollow tubular cooling element (which is made available for the aerosol to initiate the nucleation process as soon as the aerosol components leave the aerosol generating substrate) and the cross-sectional surface area of the hollow tubular cooling element are effectively maximized, while at the same time not only preventing the disintegration of the aerosol generating article, but also ensuring that the hollow tubular cooling element has the structural strength necessary to provide a certain degree of support to the aerosol generating segment and that the RTD of the hollow tubular cooling element is minimized. A larger value of the cross-sectional surface area of the cavity of the hollow tubular cooling element is understood to be associated with a reduced velocity of the aerosol flow along the aerosol generating article, which is also expected to be advantageous for aerosol nucleation. Furthermore, by using a hollow tubular cooling element having a relatively small thickness, it may be possible to substantially prevent the diffusion of the ventilation air before it contacts and mixes with the aerosol flow, which is also understood to be more advantageous for the nucleation phenomenon. In fact, by providing more controllably localized cooling of the flow of the volatilized species, it is possible to enhance the cooling effect on the formation of new aerosol particles.

[0290] The hollow tubular cooling element preferably has an outer diameter that is approximately equal to the outer diameter of the aerosol generating segment and the outer diameter of the aerosol generating article.

[0291] The hollow tubular cooling element may have an inner diameter. Preferably, the hollow tubular cooling element may have a constant inner diameter along the length of the hollow tubular cooling element. However, the inner diameter of the hollow tubular cooling element may vary along the length of the hollow tubular cooling element.

[0292] 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.

[0293] By providing a hollow tubular cooling element having an inner diameter as presented above, advantageously, sufficient rigidity and strength can be provided to the hollow tubular cooling element.

[0294] The hollow tubular cooling element may have an inner diameter of 10 millimeters or less. For example, the hollow tubular cooling element may have an inner diameter of 9 millimeters or less, 8 millimeters or less, or 7 millimeters or less.

[0295] The provision of a hollow tubular cooling element having an inner diameter as presented above may advantageously reduce the drawing resistance of the hollow tubular cooling element.

[0296] 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.

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

[0298] Preferably, the hollow tubular cooling element may include cardboard. The hollow tubular cooling element can be a cardboard tube. The hollow tubular cooling element can be formed from cardboard.

[0299] The hollow tubular cooling element may include polymeric materials. For example, the hollow tubular cooling element may include a polymeric film. The polymeric film may include a cellulose film. The hollow tubular cooling element may include low density polyethylene (LDPE) or polyhydroxyalkanoate (PHA) fibers. The hollow tube may include cellulose acetate tow.

[0300] In some embodiments, the aerosol generating article according to the present invention may include a ventilation zone at a location along the downstream section. More specifically, in those embodiments where the downstream section comprises a hollow tubular cooling element, the ventilation zone may be provided at a position along the hollow tubular cooling element. Alternatively, in those embodiments where the downstream section comprises a downstream hollow tubular element, the ventilation zone may be provided at a position along the downstream hollow tubular element.

[0301] Thus, a vented cavity is provided downstream of the aerosol generating segment. This provides several potential technical advantages.

[0302] First, the inventors have found that one such vented hollow tubular cooling element provides particularly efficient cooling of the aerosol. Therefore, satisfactory cooling of the aerosol can be achieved even by a relatively short downstream section.

[0303] Second, the inventors have surprisingly found that such rapid cooling of the volatile species released upon heating of the aerosol generating substrate promotes and enhances the nucleation of aerosol particles.

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

[0305] The aerosol generating article according to the present invention may have a ventilation level of at least 25 percent.

[0306] The term "ventilation level" is used throughout this specification to mean the volume ratio between the airflow entering the aerosol generating article through the ventilation zone (ventilation airflow) and the sum of the aerosol airflow and the ventilation airflow. The greater the ventilation level, the higher the dilution of the aerosol stream delivered to the consumer. The aerosol generating article preferably has a ventilation level of at least 25 percent, more preferably at least 30 percent, still more preferably at least 40 percent, and still more preferably at least 50 percent.

[0307] The aerosol generating article according to the present invention may have a ventilation level of up to 90 percent. Preferably, the aerosol generating article according to the present invention has a ventilation level of 80 percent or less, more preferably 70 percent or less, and still more preferably 60 percent or less.

[0308] Without wishing to be bound by theory, the inventors have found that the temperature drop resulting from introducing cooler outside air into the hollow tubular cooling element through the ventilation zone may have an advantageous effect on the nucleation and growth of aerosol particles.

[0309] As discussed in this disclosure, the downstream section may comprise a downstream filter segment. The downstream filter segment may extend to the downstream end of the downstream section. The downstream filter segment may be located at the downstream end of the aerosol generating article. The downstream end of the downstream filter segment may define the downstream end of the aerosol generating article.

[0310] The downstream filter segment may be located downstream of the hollow tubular cooling element, as described above. The downstream filter segment may extend between the hollow tubular cooling element and the downstream end of the aerosol generating article.

[0311] The downstream filter segment is preferably a solid plug, which may also be described as a "plane" plug and is non-tubular. Therefore, the filter segment preferably has a substantially uniform cross-sectional area.

[0312] The downstream filter segment is preferably formed of a fibrous filter material. The fibrous filter material can be for filtering the aerosol generated from the aerosol generating substrate. Suitable fibrous filter materials will be known to those skilled in the art. Particularly preferably, at least one downstream filter segment includes a cellulose acetate filter segment formed from cellulose acetate tow.

[0313] In a particular preferred embodiment, the downstream section includes a single downstream filter segment. In an alternative embodiment, the downstream section includes two or more downstream filter segments axially aligned in an end-to-end abutting relationship with each other.

[0314] The downstream filter segment may optionally contain a flavorant provided in any suitable form. For example, the downstream filter segment may comprise one or more capsules, beads, or granules of flavorant, or threads or filaments filled with one or more flavors.

[0315] The downstream filter segment preferably has a low particle filtration efficiency.

[0316] The downstream filter segment is preferably surrounded by a plug wrap. The downstream filter segment is preferably non-vented so that air does not enter the aerosol generating article along the downstream filter segment.

[0317] The downstream filter segment is preferably connected by a tipping wrapper to one or more of the adjacent upstream components of the aerosol generating article.

[0318] The downstream filter segment preferably has an outer diameter substantially equal to the outer diameter of the aerosol-generating article. The diameter of the downstream filter segment may be substantially the same as the outer diameter of the hollow tubular cooling element.

[0319] The outer diameter of the downstream filter segment may be from 5 millimeters to 12 millimeters. The diameter of the downstream filter segment may be from 6 millimeters to 10 millimeters, or from 7 millimeters to 8 millimeters. In certain embodiments, the diameter of the downstream filter segment may be less than 7 millimeters, for example from 5 millimeters to 7 millimeters, or from 6 millimeters to 7 millimeters.

[0320] Unless otherwise specified, the draw resistance (RTD) of a component or aerosol-generating article is measured in accordance with ISO6565-2015. RTD refers to the pressure required to force air through the entire length of the component. The terms "pressure drop" or "draw resistance" of a component or article may also refer to "resistance to draw". Such terms generally refer to measurements in accordance with ISO 6565-2015 being carried out under test conditions of a temperature of 22 degrees Celsius, a pressure of 101 kPa (about 760 Torr), and a relative humidity of 60%, with a volume flow rate of 17.5 milliliters per second at the output or downstream end of the component being measured. The conditions for smoking and the specifications of the smoking machine are presented in ISO standard 3308 (ISO3308:2000). The atmosphere for conditioning and testing is presented in ISO standard 3402 (ISO3402:1999).

[0321] The draw resistance (RTD) of the downstream section may be at least 0 millimeter H2O. The RTD of the downstream section may be at least 3 millimeters H2O. The RTD of the downstream section may be at least 6 millimeters H2O.

[0322] The RTD of the downstream section may be 12 millimeters of H2O or less. The RTD of the downstream section may be 11 millimeters of H2O or less. The RTD of the downstream section may be 10 millimeters of H2O or less.

[0323] The length of the downstream filter segment may be at least 5 millimeters. The length of the downstream filter segment may be at least 10 millimeters. The length of the downstream filter segment may be less than 25 millimeters. The length of the downstream filter segment may be less than 20 millimeters. For example, the length of the downstream filter segment may be 5 millimeters to 25 millimeters, or 10 millimeters to 25 millimeters, or 5 millimeters to 20 millimeters, or 10 millimeters to 20 millimeters.

[0324] The downstream section may further comprise one or more additional hollow tubular elements.

[0325] In certain embodiments, the downstream section may comprise a hollow tubular support element upstream of the hollow tubular cooling element described above. The hollow tubular support element preferably abuts against the downstream end of the second aerosol generation segment, or the third aerosol generation segment if present. Preferably, the hollow tubular support element abuts against the upstream end of the hollow tubular cooling element. The hollow tubular support element and the hollow tubular cooling element are preferably adjacent to each other and together provide a hollow tubular section within the downstream section.

[0326] As an alternative to, or in addition to, the hollow tubular support element, the downstream section may further comprise a downstream hollow tubular element downstream of the hollow tubular cooling element. The downstream hollow tubular element may be provided immediately adjacent to the hollow tubular cooling element. If the downstream section further comprises the additional downstream hollow tubular element described above, the additional downstream hollow tubular element may be formed of the same material or a different material as the downstream hollow tubular element.

[0327] In certain preferred embodiments, the downstream section may comprise a venting zone at a location on the downstream hollow tubular element. In one example, this venting zone at a location on the downstream hollow tubular element may be provided in place of the venting zone at a location on the hollow tubular cooling element. In another example, the venting zone at a location on the downstream hollow tubular element may be provided in addition to the venting zone provided at a location on the hollow tubular cooling element.

[0328] The venting zone at a location along the downstream hollow tubular element may include a plurality of perforations through the circumferential wall of the downstream hollow tubular element. The venting zone at a location along the downstream hollow tubular element preferably includes at least one circumferential row of perforations. In some embodiments, the venting zone may include two circumferential rows of perforations. For example, the perforations may be formed online during the manufacture of the aerosol-generating article. Preferably, each circumferential row of perforations includes from 8 to 30 perforations.

[0329] The downstream section may optionally further comprise additional cooling elements that define a plurality of longitudinally extending channels, such as to make available a large surface area for heat exchange. In other words, one such additional cooling element is adapted to function substantially as a heat exchanger. The plurality of longitudinally extending channels may be defined by a sheet material that has been pleated, assembled, or folded to form the channels. The plurality of longitudinally extending channels may be defined by a single sheet that has been pleated, assembled, or folded to form the plurality of channels. The sheet may also be crimped before being pleated, assembled, or folded. Alternatively, the plurality of longitudinally extending channels may be defined by a plurality of sheets that have been crimped, pleated, assembled, or folded to form the plurality of channels. In some embodiments, the plurality of longitudinally extending channels may be defined by a plurality of sheets that have been crimped, pleated, assembled, or folded, i.e., brought into an overlay arrangement and then defined by two or more sheets that have been crimped, pleated, assembled, or folded as one.

[0330] As used herein, the term "crimped" means a sheet having a plurality of substantially parallel ridges or corrugations. When the aerosol-generating article is assembled, the substantially parallel ridges or corrugations preferably extend in the longitudinal axis direction. As used herein, the terms "assembled," "pleated," or "folded" mean that a sheet of material is spiraled, folded, or otherwise compressed or contracted substantially transversely to the cylindrical axis of the aerosol-generating article. The sheet may be crimped before being assembled, pleated, or folded. The sheet may be assembled, pleated, or folded without prior crimping.

[0331] One such additional cooling element may have a total surface area of from about 300 square millimeters per millimeter of length to about 1000 square millimeters per millimeter of length.

[0332] The additional cooling element preferably provides a low draw resistance to the passage of air through the additional cooling element. The additional cooling element preferably does not substantially affect the draw resistance of the aerosol-generating article. To achieve this, it is preferred that the longitudinal porosity exceeds 50 percent and that the airflow path through the additional cooling element is relatively unconstrained. The longitudinal porosity of the additional cooling element may be defined by the ratio of the cross-sectional area of the material forming the additional cooling element to the internal cross-sectional area of the aerosol-generating article at the location of the portion containing the additional cooling element.

[0333] The additional cooling element comprises a sheet material selected from the group comprising metal foils, polymer sheets, and substantially non-porous paper or cardboard. In some embodiments, the aerosol cooling element may comprise a sheet material selected from the group consisting of polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polyethylene terephthalate (PET), polylactic acid (PLA), cellulose acetate (CA), and aluminum foil. In particularly preferred embodiments, the additional cooling element comprises a sheet of PLA.

[0334] Preferably, the total length of the aerosol-generating article according to the present invention is at least 40 millimeters. More preferably, the total length of the aerosol-generating article according to the present invention is at least 50 millimeters. Even more preferably, the total length of the aerosol-generating article according to the present invention is at least 60 millimeters.

[0335] Preferably, the total length of the aerosol-generating article according to the present invention is 90 millimeters or less. More preferably, the total length of the aerosol-generating article according to the present invention is 85 millimeters or less. Even more preferably, the total length of the aerosol-generating article according to the present invention is 80 millimeters or less.

[0336] In some embodiments, the total 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 total length of the aerosol-generating article is preferably from 40 millimeters to 60 millimeters, more preferably from about 45 millimeters to about 60 millimeters. In further embodiments, the total 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 total length of the aerosol-generating article is about 45 millimeters.

[0337] In an alternative embodiment, the overall length of the aerosol-generating article is preferably from 50 millimeters to 90 millimeters, more preferably from 60 millimeters to 90 millimeters, and even more preferably from 70 millimeters to 90 millimeters. In other embodiments, the overall length of the aerosol-generating article is preferably from 50 millimeters to 85 millimeters, more preferably from 60 millimeters to 85 millimeters, and even more preferably from 70 millimeters to 85 millimeters. In a further embodiment, the overall length of the aerosol-generating article is preferably from 50 millimeters to 80 millimeters, more preferably from 60 millimeters to 80 millimeters, and even more preferably from 70 millimeters to 80 millimeters. In an exemplary embodiment, the overall length of the aerosol-generating article is 75 millimeters.

[0338] The aerosol-generating article has an outer diameter of at least 5 millimeters. Preferably, the aerosol-generating article has an outer diameter of at least 6 millimeters. More preferably, the aerosol-generating article has an outer diameter of at least 7 millimeters.

[0339] Preferably, the aerosol-generating article has an outer diameter of about 12 millimeters or less. More preferably, the aerosol-generating article has an outer diameter of about 10 millimeters or less. Even more preferably, the aerosol-generating article has an outer diameter of about 8 millimeters or less.

[0340] In some embodiments, the aerosol generating article has an outer diameter of from about 5 millimeters to about 12 millimeters, preferably from about 6 millimeters to about 12 millimeters, more preferably from about 7 millimeters to about 12 millimeters. In other embodiments, the aerosol generating article has an outer diameter of from about 5 millimeters to about 10 millimeters, preferably from about 6 millimeters to about 10 millimeters, more preferably from about 7 millimeters to about 10 millimeters. In further embodiments, the aerosol generating article has an outer diameter of from about 5 millimeters to about 8 millimeters, preferably from about 6 millimeters to about 8 millimeters, more preferably from about 7 millimeters to about 8 millimeters. In other embodiments, the aerosol generating article has an outer diameter of less than 7 millimeters.

[0341] The outer diameter of the aerosol generating article can be substantially constant over the entire length of the article. Alternatively, different portions of the aerosol generating article may have different outer diameters.

[0342] In particularly preferred embodiments, one or more of the components of the aerosol generating article are individually surrounded by their own wrapper.

[0343] In one embodiment, the first aerosol generating segment, the second aerosol generating segment, and the mouthpiece element are individually wrapped. The upstream element (if present), the first aerosol generating segment, the second aerosol generating segment, and the hollow tubular element are then combined together with an outer wrapper. Thereafter, they are combined with a downstream filter element having its own wrapper by tipping paper.

[0344] Preferably, at least one of the components of the aerosol generating article is wrapped in a hydrophobic wrapper.

[0345] The term "hydrophobic" refers to a surface that exhibits water-repellent properties. One useful way to determine this is by measuring the water contact angle. The "water contact angle" is the angle conventionally measured through a liquid, where the liquid / vapor interface meets the solid surface. This quantifies the wetting of the solid surface by the liquid via Young's equation. The hydrophobicity or water contact angle may be determined by utilizing the TAPPI T558 test method, and the results are expressed as the interfacial contact angle and reported in "degrees", which can range from approximately zero to approximately 180 degrees.

[0346] In a preferred embodiment, the hydrophobic wrapper comprises a paper layer having a water contact angle of about 30 degrees or more, preferably about 35 degrees or more, or about 40 degrees or more, or about 45 degrees or more.

[0347] By way of example, the paper layer may include PVOH (polyvinyl alcohol) or silicon. The PVOH may be applied to the paper layer as a surface coating, or the paper layer may include a surface treatment containing PVOH or silicon.

[0348] In certain embodiments of the present invention, the aerosol-generating article further comprises one or more elongated susceptor elements within one or both of the first aerosol-generating segment and the second aerosol-generating segment. For example, the one or more elongated susceptor elements may be disposed substantially in the longitudinal direction within one or both of the first aerosol-generating segment and the second aerosol-generating segment and may be in thermal contact with one or both of the first aerosol-generating substrate and the second aerosol-generating substrate.

[0349] As used herein with respect to the present invention, the term "susceptor element" refers to a material capable of converting electromagnetic energy into heat. When positioned within a varying electromagnetic field, the induced eddy currents in the susceptor element cause heating of the susceptor element. Since the susceptor element is positioned in thermal contact with the aerosol-generating substrate, the aerosol-generating substrate is heated by the susceptor element.

[0350] When used to describe a susceptor element, the term "elongated" means that the susceptor element has a length dimension that is greater than its width dimension or its thickness dimension, e.g., greater than twice its width dimension or its thickness dimension.

[0351] The susceptor element is disposed substantially in the longitudinal direction within at least one of the first and second aerosol generating segments. This means that the length dimension of the elongated susceptor element is substantially parallel to the longitudinal direction of at least one of the first and second aerosol generating segments, e.g., within ±10 degrees parallel to the longitudinal direction of at least one of the first and second aerosol generating segments. In a preferred embodiment, the elongated susceptor element may be positioned at a radially central position within at least one of the first and second aerosol generating segments and extends along the longitudinal axis of at least one of the first and second aerosol generating segments.

[0352] Preferably, the susceptor element extends entirely to at least one downstream end of at least one of the first and second aerosol generating segments. In some embodiments, the susceptor element may extend entirely to at least one upstream end of at least one of the first and second aerosol generating segments. In a particularly preferred embodiment, the susceptor element has substantially the same length as the aerosol generating segment in which it is included and extends from the upstream end of the segment to the downstream end of the segment.

[0353] The susceptor element is preferably in the form of a pin, rod, strip, or blade.

[0354] The susceptor element preferably has a length of from 10 millimeters to 40 millimeters, e.g., from 15 millimeters to 35 millimeters, or from 17 millimeters to 30 millimeters.

[0355] The susceptor element preferably has a length of from 5 millimeters to 15 millimeters, e.g., from 6 millimeters to 12 millimeters, or from 8 millimeters to 10 millimeters.

[0356] The susceptor element preferably has a width of 1 millimeter to 5 millimeters.

[0357] The susceptor element can generally have a thickness of 0.01 millimeter to 2 millimeters, for example, 0.5 millimeter to 2 millimeters. In some embodiments, the susceptor element preferably has a thickness of 10 micrometers to 500 micrometers, more preferably 10 micrometers to 100 micrometers.

[0358] The elongated susceptor element preferably has a length that is the same as or shorter than the length of the aerosol generating segment in which it is incorporated. The elongated susceptor element preferably has the same length as the length of the aerosol generating segment in which it is incorporated.

[0359] The susceptor element can be formed from any material that can be inductively heated to a temperature sufficient to generate an aerosol from the aerosol generating substrate. Preferred susceptor elements include metal or carbon.

[0360] Preferred susceptor elements may include, for example, ferromagnetic alloys, ferrite iron, or ferromagnetic steels, such as stainless steel, or may consist of ferromagnetic materials. Suitable susceptor elements may be aluminum or may include aluminum. Preferred susceptor elements may be formed from 400 series stainless steels, such as grade 410, or grade 420, or grade 430 stainless steel. Different materials dissipate different amounts of energy when positioned within an electromagnetic field having similar values of frequency and magnetic field strength.

[0361] Thus, any of the parameters of the susceptor element, such as the type, length, width, and thickness of the material, can be varied to provide the desired power dissipation within a known electromagnetic field. Preferred susceptor elements may be heated to temperatures exceeding 250 degrees Celsius.

[0362] A suitable susceptor element may comprise a non-metallic core with a metal layer, such as a metal strip formed on the surface of a ceramic core, disposed thereon. The susceptor element may have a protective outer layer, such as a protective ceramic layer or a protective glass layer, enclosing the susceptor element. The susceptor element may comprise a protective coating formed of glass, ceramic, or an inert metal, formed over the core of the susceptor element material.

[0363] The susceptor element is disposed in thermal contact with the aerosol-generating substrate of the aerosol-generating segment in which the susceptor element is incorporated. Thus, when the temperature of the susceptor element increases, the aerosol-generating substrate is heated and an aerosol is formed. The susceptor element is preferably disposed in physical direct contact with the aerosol-generating substrate, for example, within the aerosol-generating substrate.

[0364] The first aerosol-generating substrate may be surrounded by a first wrapper. The second aerosol-generating substrate may be surrounded by a second wrapper separate from the first wrapper. Thus, each aerosol-generating segment has a unique separate plug wrapper around its respective aerosol-generating substrate.

[0365] The first aerosol-generating segment and the second aerosol-generating segment may be surrounded by a further wrapper, which may combine the aerosol-generating segments and hold them in a predetermined position relative to each other.

[0366] The wrapper surrounding the first aerosol generation substrate, the second aerosol generation substrate, or the first aerosol generation segment and the second aerosol generation segment may be a paper wrapper or a wrapper other than paper. Suitable paper wrappers for use in particular embodiments of the present invention are known in the art and include, but are not limited to, cigarette papers and filter plug wrappers. Suitable non-paper wrappers for use in particular embodiments of the present invention are known in the art and include, but are not limited to, sheets of homogenized tobacco material.

[0367] The paper wrapper may have a basis weight of at least 15 gsm (grams per square meter), preferably at least 20 gsm. The paper wrapper may have a basis weight of 35 gsm or less, preferably 30 gsm or less. The paper wrapper may have a basis weight of 15 gsm to 35 gsm, preferably 20 gsm to 30 gsm. In a preferred embodiment, the paper wrapper may have a basis weight of 25 gsm. The paper wrapper may have a thickness of at least 25 micrometers, preferably at least 30 micrometers, more preferably at least 35 micrometers. The paper wrapper may have a thickness of about 55 micrometers or less, preferably about 50 micrometers or less, more preferably about 45 micrometers or less. The paper wrapper may have a thickness of 25 micrometers to 55 micrometers, preferably 30 micrometers to 50 micrometers, more preferably 35 micrometers to 45 micrometers. In a preferred embodiment, the paper wrapper may have a thickness of 40 microns.

[0368] In certain preferred embodiments, the wrapper may be formed from a laminated material comprising a plurality of layers. The wrapper is preferably formed from an aluminum co-laminated sheet. The use of a co-laminated sheet containing aluminum advantageously prevents combustion of the aerosol generation substrate when the aerosol generation substrate is to be ignited rather than heated in the manner intended.

[0369] The paper layer of the co-laminated sheet may have a basis weight of at least 35 gsm, preferably at least 40 gsm. The paper layer of the co-laminated sheet may have a basis weight of 55 gsm or less, preferably 50 gsm or less. The paper layer of the co-laminated sheet may have a basis weight of 35 gsm to 55 gsm, preferably 40 gsm to 50 gsm. In a preferred embodiment, the paper layer of the co-laminated sheet may have a basis weight of 45 gsm.

[0370] The paper layer of the co-laminated sheet may have a thickness of at least 50 micrometers, preferably at least 55 micrometers, more preferably at least 60 micrometers. The paper layer of the co-laminated sheet may have a thickness of 80 micrometers or less, preferably 75 micrometers or less, more preferably 70 micrometers or less.

[0371] The paper layer of the co-laminated sheet may have a thickness of about 50 micrometers to about 80 micrometers, preferably about 55 micrometers to about 75 micrometers, more preferably about 60 micrometers to about 70 micrometers. In a preferred embodiment, the paper layer of the co-laminated sheet may have a thickness of 65 microns.

[0372] The metal layer of the co-laminated sheet may have a basis weight of at least 12 gsm, preferably at least 15 gsm. The metal layer of the co-laminated sheet may have a basis weight of 25 gsm or less, preferably 20 gsm or less. The metal layer of the co-laminated sheet may have a basis weight of 12 gsm to 25 gsm, preferably 15 gsm to 20 gsm. In a preferred embodiment, the metal layer of the co-laminated sheet may have a basis weight of 17 gsm.

[0373] The metal layer of the co-laminated sheet may have a thickness of at least 2 micrometers, preferably at least 3 micrometers, more preferably at least 5 micrometers. The metal layer of the co-laminated sheet may have a thickness of 15 micrometers or less, preferably 12 micrometers or less, more preferably 10 micrometers or less.

[0374] The metal layer of the co-laminated sheet may have a thickness of about 2 micrometers to about 15 micrometers, preferably about 3 micrometers to about 12 micrometers, more preferably about 5 micrometers to about 10 micrometers. In a preferred embodiment, the metal layer of the co-laminated sheet may have a thickness of 6 microns.

[0375] The wrapper surrounding the first aerosol generating segment and the second aerosol generating segment may be a paper wrapper containing PVOH (polyvinyl alcohol) or silicon (or polysiloxane). The addition of PVOH (polyvinyl alcohol) or silicon (or polysiloxane) may improve the grease barrier properties of the wrapper.

[0376] PVOH or silicon (or polysiloxane) can be applied to the paper layer as a surface coating, such as being disposed on the outer surface of the paper layer of the wrapper surrounding the first aerosol generating segment and the second aerosol generating segment. PVOH or silicon (or polysiloxane) may be disposed on the outer surface of the paper layer of the wrapper and may form a layer. PVOH or silicon (or polysiloxane) may be disposed on the inner surface of the paper layer of the wrapper. PVOH or silicon (or polysiloxane) may be disposed on the inner surface of the paper layer of the aerosol article and may form a layer.

[0377] The paper wrapper containing PVOH or silicon (or polysiloxane) may have a basis weight of at least 20 gsm, preferably at least 25 gsm, more preferably at least 30 gsm. The paper wrapper containing PVOH or silicon (or polysiloxane) may have a basis weight of 50 gsm or less, preferably 45 gsm or less, more preferably 40 gsm or less.

[0378] The paper wrapper containing PVOH or silicon (or polysiloxane) may have a thickness of at least 25 micrometers, preferably at least 30 micrometers, more preferably at least 35 micrometers. The paper wrapper containing PVOH or silicon (or polysiloxane) may have a thickness of 50 micrometers or less, preferably 45 micrometers or less, more preferably 40 micrometers or less.

[0379] The wrapper surrounding the first aerosol generating segment and the second aerosol generating segment may contain a flame retardant composition comprising one or more flame retardant compounds. The term "flame retardant compound" is used herein to describe a compound that, when added to or otherwise incorporated into a carrier substrate such as a paper or plastic compound, provides varying degrees of flammability protection to the carrier substrate. In fact, the flame retardant compound may be activated by the presence of an ignition source and is adapted to prevent or slow further progression of ignition by a variety of different physical and chemical mechanisms.

[0380] The flame retardant composition typically further comprises one or more non-flame retardant compounds, i.e., compounds that do not actively contribute to providing flammability protection to the carrier substrate, but are used to facilitate the application of the flame retardant compound onto, into, or both onto and into the wrapper. Some of the non-flame retardant compounds of the flame retardant composition (such as solvents) may be volatile and may evaporate from the wrapper upon drying after the flame retardant composition has been applied onto, into, or both onto and into the wrapping substrate. Thus, although such non-flame retardant compounds form part of the formulation of the flame retardant composition, they may no longer be present, or may only be detectable in trace amounts, in the wrapper of the aerosol generating article.

[0381] For example, the flame retardant composition may include a polymer, at least one mono-, di-, and / or tricarboxylic acid, at least one polyphosphoric acid, pyrophosphoric acid, and / or phosphoric acid, and a mixed salt based on a hydroxide or a salt of an alkali or alkaline earth metal. When at least one mono-, di-, and / or tricarboxylic acid and the hydroxide or salt form a carboxylate and at least one polyphosphoric acid, pyrophosphoric acid and / or phosphoric acid, and the hydroxide or salt form a phosphate. Preferably, the flame retardant composition further includes a carbonate of an alkali or alkaline earth metal.

[0382] In the following, the present invention will be further described with reference to the accompanying drawings.

Brief Description of the Drawings

[0383]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Modes for Carrying Out the Invention

[0384] The following is a non-exhaustive list of non-limiting examples. Any one or more of the features of these examples may be combined with any one or more of the features of any other example, embodiment, or aspect described herein.

[0385] Example 1: An aerosol generating system for use with an aerosol generating article, the aerosol generating system comprising: an aerosol generating device comprising a heating chamber for receiving the aerosol generating article and a heater assembly disposed along a portion of the heating chamber defining a heating zone; and an aerosol generating article received within the heating chamber of the aerosol generating device, the aerosol generating article comprising a first aerosol generating segment comprising a first aerosol generating substrate and a second aerosol generating segment comprising a second aerosol generating substrate, wherein when the aerosol generating article is fully received within the heating chamber of the aerosol generating device, the aerosol generating system is configured such that no more than 50 percent of the length of the first aerosol generating segment is within the heating zone and at least 90 percent of the length of the second aerosol generating segment is within the heating zone. Example 1a: An aerosol generating system for use with an aerosol generating article, the aerosol generating system comprising: an aerosol generating device comprising a heating chamber for receiving the aerosol generating article and a heater assembly disposed along a portion of the heating chamber defining a heating zone; and an aerosol generating article received within the heating chamber of the aerosol generating device, the aerosol generating article comprising a first aerosol generating segment comprising a first aerosol generating substrate and a second aerosol generating segment comprising a second aerosol generating substrate, wherein when the aerosol generating article is fully received within the heating chamber of the aerosol generating device, the aerosol generating system is configured such that at least 90 percent of the length of the second aerosol generating segment is within the heating zone. Example 1b: The aerosol generation system according to Example 1 or Example 1a, wherein the first aerosol generation segment is located upstream of the second aerosol generation segment. Example 1c: The aerosol generation system according to any one of Examples 1 to 1b, wherein the length of the first aerosol generation segment is shorter than the length of the second aerosol generation segment. Example 1d: The aerosol generation system according to any one of Examples 1 to 1c, wherein the second aerosol generation segment has a length of 9 millimeters to 15 millimeters. Example 1e: The aerosol generation system according to any one of Examples 1 to 1d, wherein the combined length of the first aerosol generation segment and the second aerosol generation segment is 15 millimeters to 25 millimeters. Example 3: The aerosol generation system according to any one of Examples 1 to 1e, wherein the first aerosol generation segment has an upstream end, and the upstream end of the first aerosol generation segment defines the upstream end of the aerosol generating article. Example 4: The aerosol generation system according to any one of Examples 1 to 3, wherein the upstream end of the second aerosol generation segment is in direct contact with the downstream end of the first aerosol generation segment. Example 6: The aerosol generation system according to any one of Examples 1 to 4, wherein the length of the second aerosol generation segment is at least 3 millimeters greater than the length of the first aerosol generation segment. Example 8: The aerosol generation system according to any one of Examples 1 to 6, wherein the first aerosol generation segment has a length of at least 2 millimeters. Example 9: The aerosol generation system according to any one of Examples 1 to 8, wherein the first aerosol generation segment has a length of 8 millimeters or less. Example 10: The aerosol generation system according to any one of Examples 1 to 9, wherein the second aerosol generation segment has a length of at least 8 millimeters. Example 11: The aerosol generation system according to any one of Examples 1 to 10, wherein the second aerosol generation segment has a length of 16 millimeters or less. Example 12: The aerosol generation system according to any one of Examples 1 to 11, wherein the heater assembly includes at least one of a resistive heating element and an induction heating assembly. Example 12a: The aerosol generation system according to any one of Examples 1 to 12, wherein the heater assembly includes an induction heating element and an inductor coil. Example 13: The aerosol generation system according to any one of Examples 1 to 12a, wherein the first aerosol generation substrate has a first density, the second aerosol generation substrate has a second density, and the second density is greater than the first density. Example 14: The aerosol generation article according to any one of Examples 1 to 13, wherein the density of the second aerosol generation substrate is at least 100 mg higher per cubic centimeter than the density of the first aerosol generation substrate. Example 15: The aerosol generation system according to any one of Examples 1 to 14, wherein the density of the first aerosol generation substrate is less than 400 mg per cubic centimeter. Example 16: The aerosol generation article according to any one of Examples 1 to 15, wherein the first aerosol generation substrate has a density of 100 mg per cubic centimeter to 400 mg per cubic centimeter. Example 17: The aerosol generation system according to any one of Examples 1 to 16, wherein the density of the second aerosol generation substrate is at least 500 mg per cubic centimeter. Example 18: The second aerosol generating substrate is the aerosol generating article according to any one of Examples 1 to 17, having a density of 500 mg per cubic centimeter to 1000 mg per cubic centimeter. Example 19: The aerosol generating article according to any one of Examples 1 to 18, wherein the density of the second aerosol generating substrate is at least 1.2 times the density of the first aerosol generating substrate. Example 20: The aerosol generating article according to any one of Examples 1 to 19, wherein the first aerosol generating substrate contains cut tobacco material. Example 21: The aerosol generating system according to Example 20, wherein the first aerosol generating substrate contains tobacco cut filler. Example 22: The aerosol generating article according to any one of Examples 1 to 21, wherein the first aerosol generating substrate contains a sheet of homogenized cut tobacco material. Example 23: The aerosol generating article according to any one of Examples 1 to 22, wherein the second aerosol generating substrate contains an aerosol generating film. Example 24: The aerosol generating system according to Example 23, wherein the second aerosol generating substrate contains an aerosol generating film, the aerosol generating film contains a cellulose-based film former, nicotine, and glycerol, and the aerosol generating film has a glycerol content of at least 40 weight percent. Example 25: The aerosol generating article according to Example 24, wherein the second aerosol generating substrate contains at least 50 weight percent glycerol. Example 26: The aerosol generating article according to any one of Examples 23 to 25, wherein the aerosol generating film contains a cellulose-based film former, nicotine, and an aerosol former. Example 27: The aerosol generating article according to any one of Examples 23 to 26, wherein the aerosol generating film further contains a cellulose-based strengthening agent. Example 28: An aerosol-generating article according to any one of Examples 23 to 27, wherein the aerosol-generating film further comprises carboxymethylcellulose. Example 29: An aerosol-generating article according to any one of Examples 23 to 28, wherein the aerosol-generating film further comprises an acid. Example 30: An aerosol-generating article according to any one of Examples 23 to 29, wherein the aerosol-generating film is substantially tobacco-free. Example 31: An aerosol-generating article according to any one of Examples 1 to 30, wherein the second aerosol-generating substrate comprises a gel composition comprising nicotine, at least one gelling agent, and an aerosol former. Example 32: An aerosol-generating system according to any one of Examples 1 to 31, wherein the first aerosol-generating substrate and the second aerosol-generating substrate each comprise at least one aerosol former, and the aerosol former content of the second aerosol-generating substrate is greater than the aerosol former content of the first aerosol-generating substrate. Example 33: An aerosol-generating system according to any one of Examples 1 to 32, wherein the first aerosol-generating substrate comprises at least one aerosol former, and the aerosol former content of the first aerosol-generating substrate is 30 weight percent or less on a dry weight basis. Example 34: An aerosol-generating system according to Example 32 or Example 33, wherein the second aerosol-generating substrate comprises at least one aerosol former, and the aerosol former content of the second aerosol-generating substrate is at least 40 weight percent on a dry weight basis. Example 35: An aerosol-generating article according to any one of Examples 32 to 34, wherein the aerosol former content of the second aerosol-generating substrate is at least 15 percent higher than the aerosol former content of the first aerosol-generating substrate. Example 36: The aerosol generating article according to any one of Examples 32 to 35, wherein the aerosol former content of the second aerosol generating substrate is at least 1.2 times that of the first aerosol generating substrate. Example 37: The aerosol generating article according to any one of Examples 32 to 36, wherein the aerosol former content of the first aerosol generating substrate is 5% to 30% by dry weight. Example 38: The aerosol generating article according to any one of Examples 32 to 37, wherein the aerosol former content of the second aerosol generating substrate is 40% to 80% by dry weight. Example 39: The aerosol generating system according to any one of Examples 1 to 38, wherein the first aerosol generating substrate of the first aerosol generating segment is surrounded by a first wrapper, and the second aerosol generating substrate of the second aerosol generating segment is surrounded by a second wrapper. Example 40: The aerosol generating article according to any one of Examples 1 to 39, further comprising a third aerosol generating segment including a third aerosol generating substrate, wherein the aerosol generating rod is provided upstream of the second aerosol generating segment. Example 41: The aerosol generating article according to Example 40, wherein the third aerosol generating substrate includes cut tobacco material. Example 42: The aerosol generating article according to Example 40 or Example 41, wherein the third aerosol generating substrate includes at least one aerosol former, and the aerosol former content of the third aerosol generating substrate is 30% or less by dry weight. Example 43: The aerosol generating article according to any one of Examples 1 to 42, further comprising a downstream section provided downstream of the first aerosol generating segment and the second aerosol generating segment. Example 44: The aerosol-generating article according to embodiment 43, wherein the downstream section extends to the downstream end of the aerosol-generating article. Example 45: The aerosol-generating article according to embodiment 43 or 44, wherein the downstream section includes a downstream filter segment. Example 46: The aerosol-generating article according to embodiment 45, wherein the downstream filter segment is a solid plug. Example 47: The aerosol-generating article according to embodiments 44 to 46, wherein the downstream filter segment has a length of at least 5 millimeters. Example 48: The aerosol-generating article according to any one of embodiments 43 to 47, wherein the downstream section comprises a hollow tubular cooling element. Example 49: The aerosol-generating article according to embodiment 48, wherein the hollow tubular cooling element has a length of at least 20 millimeters. Example 50: The aerosol-generating article according to embodiment 48 or 49, wherein the downstream section comprises a ventilation zone at a position along the hollow tubular cooling element. Example 51: The aerosol-generating article according to any one of embodiments 48 to 50, wherein the downstream section further comprises a hollow tubular support element upstream of the hollow tubular cooling element. Example 52: The aerosol-generating article according to any one of embodiments 48 to 51, wherein the downstream section further comprises a downstream hollow tubular element downstream of the hollow tubular cooling element. Example 53: The aerosol-generating article according to any one of embodiments 1 to 52, further comprising an upstream element provided upstream of the first aerosol-generating segment and the second aerosol-generating segment. Example 54: The aerosol-generating article according to any one of embodiments 1 to 53, wherein the aerosol-generating article has a ventilation level of at least 40 percent. Example 55: An aerosol generating article according to any one of Examples 1 to 54, wherein the length of the aerosol generating article is 40 millimeters to 50 millimeters. Example 56: An aerosol generating article according to any one of Examples 1 to 55, wherein the length of the aerosol generating article is 70 millimeters to 80 millimeters.

[0386] The aerosol generating article 10 shown in FIG. 1 comprises a first aerosol generating segment 24, a second aerosol generating segment 26, and a downstream section 14. The upstream end of the first aerosol generating segment 24 defines the upstream end 16 of the aerosol generating article 10. The second aerosol generating segment 26 is located immediately downstream of the first aerosol generating segment 24. The downstream end of the first aerosol generating segment 24 abuts the upstream end of the second aerosol generating segment 26. The downstream section 14 is located immediately downstream of the second aerosol generating segment 26. The downstream end of the second aerosol generating segment 26 abuts the upstream end of the downstream section 14. The downstream end of the downstream section 14 defines the downstream end 18 of the aerosol generating article 10.

[0387] The downstream section 14 comprises a hollow tubular cooling element 20 and a downstream filter segment 50.

[0388] The aerosol generating article 10 has an overall length of about 45 millimeters and an outer diameter of about 7.2 mm.

[0389] The first aerosol generating segment 24 includes a first aerosol generating substrate having a length of 5 millimeters and formed of about 50 mg of shredded tobacco material containing 15 weight percent to 20 weight percent glycerol. The density of the first aerosol generating substrate is about 300 mg per cubic centimeter. The first aerosol generating segment 24 is individually wrapped by a plug wrap (not shown).

[0390] The second aerosol generation segment 26 has a length of 12 millimeters and includes a second aerosol generation substrate formed from a fragment of the aerosol generation film. An exemplary composition of the aerosol generation film is shown in Table 1 below. [Table 1]

[0391] The second aerosol generation substrate has, as described above, a glycerol content of about 50 weight percent and thus is 10 percent higher than the glycerol content of the first aerosol generation substrate. The density of the second aerosol generation substrate is greater than 600 mg per cubic centimeter. The first aerosol generation segment 24 is individually wound by a plug wrap (not shown).

[0392] The hollow tubular cooling element 20 of the downstream section 14 is located immediately downstream of the aerosol generation rod 12, and the hollow tubular cooling element 20 is aligned with the rod 12 in the longitudinal axis direction. The upstream end of the hollow tubular cooling element 20 abuts against the downstream end of the rod 12.

[0393] The hollow tubular cooling element 20 defines a hollow section of the aerosol generation article 10. The hollow tubular cooling element 20 does not substantially contribute to the overall RTD of the aerosol generation article. More specifically, the RTD of the hollow tubular cooling element 20 is about 0 mmH2O.

[0394] 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 that extends all the way 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 is substantially empty and thus allows for a substantially unrestricted airflow along the internal cavity.

[0395] The hollow tubular cooling element 20 has a length of about 21 millimeters, an outer diameter of about 7.2 millimeters, and an inner diameter of about 6.7 millimeters. Thus, the thickness of the peripheral wall of the hollow tubular cooling element 20 is about 0.25 millimeters.

[0396] The aerosol generating article 10 comprises a ventilation zone 30 provided at a position along the hollow tubular cooling element 20. The ventilation zone 30 comprises a circumferential row of openings or perforations surrounding the hollow tubular cooling element 20. The perforations of the ventilation zone 30 extend through the wall of the hollow tubular cooling element 20 to enable the ingress of fluid from the outside of the article 10 into the internal cavity. The ventilation level of the aerosol generating article 10 is about 40 percent.

[0397] The downstream filter segment 50 extends from the downstream end of the hollow tubular cooling element 20 to the downstream or mouth end of the aerosol generating article 10. The downstream filter segment 50 has a length of about 7 millimeters. The outer diameter of the downstream filter segment 50 is about 7.2 millimeters. The downstream filter segment 50 comprises a low density cellulose acetate filter segment. The RTD of the downstream filter segment 50 is about 8 mmH2O. The downstream filter segment 50 may be individually wound by a plug wrap (not shown).

[0398] The article 10 comprises a first aerosol generating segment 24, a second aerosol generating segment 26, and an upstream wrapper 44 surrounding the hollow tubular cooling element 20. The ventilation zone 30 may also comprise a circumferential row of perforations provided on the upstream wrapper 44. The perforations of the upstream wrapper 44 overlap the perforations provided on the hollow tubular cooling element 20. Thus, the upstream wrapper 44 is over the perforations of the ventilation zone 30 provided on the hollow tubular cooling element 20.

[0399] The article 10 also comprises a tipping wrapper 52 surrounding the hollow tubular cooling element 20 and the mouthpiece element 50. The tipping wrapper 52 is on top of a portion of the upstream wrapper 44 which is on top of the hollow tubular cooling element 20. Thus, the tipping wrapper 52 effectively couples the mouthpiece element 50 to the remaining components of the article 10. The width of the tipper wrapper 52 is about 26 millimeters. Additionally, the ventilation zone 30 may comprise a circumferential row of perforations provided on the tipping wrapper 52. The perforations of the tipping wrapper 52 overlap with the perforations provided on the hollow tubular cooling element 20 and on the upstream wrapper 44. Thus, the tipping wrapper 52 is on top of the perforations of the ventilation zone 30 provided on the hollow tubular cooling element 20 and on the upstream wrapper 44.

[0400] Figure 2 illustrates a first aerosol generating system 100 according to the present invention. The first aerosol generating system 100 comprises the first aerosol generating article 10 of FIG. 1 and a downstream portion of the aerosol generating device 1. The aerosol generating device 1 comprises a housing (or body) 4 extending between a downstream end 2 and an upstream end (not shown). The housing 4 comprises a peripheral wall 6. The peripheral wall 6 defines a heating chamber 3 for receiving the aerosol generating article 10. The heating chamber 3 is defined by a closed upstream end and an open downstream end. The downstream end of the heating chamber 3 is located at the downstream end of the aerosol generating device 1. The aerosol generating article 10 is configured to be received through the open downstream end of the heating chamber 3 and to abut against the closed upstream end of the device cavity when the aerosol generating article 10 is fully received within the heating chamber 3.

[0401] An air flow channel 5 of the device is defined within the peripheral wall 6. The air flow channel 5 extends between an inlet 7 located at the mouth side end of the aerosol generating device 1 and the closed end of the device cavity. Air may enter the aerosol generating substrate 12 through an opening (not shown) provided at the closed end of the device cavity to ensure fluid communication between the air flow channel 5 and the aerosol generating substrate 12.

[0402] The aerosol generating device 1 further includes a heater assembly 15 and a power source (not shown) for supplying power to the heater assembly 15. A controller (not shown) is also provided to control the supply of such power to the heater assembly 15. The heater assembly 15 is configured to controllably heat the aerosol generating article 10 during use when the aerosol generating article 1 is fully received within the heating chamber 3.

[0403] The heater assembly 15 extends from an upstream end defining a heating zone to a downstream end. The heater assembly 15 has the same length as the second aerosol generating segment 26 such that when the aerosol generating article 10 is fully received within the heating chamber 3, the entire length of the second aerosol generating segment 26 is received within the heating zone to provide optimal heating of the aerosol generating segment 26. When the aerosol generating article 10 is fully received within the heating chamber 3, the first aerosol generating segment 24 is disposed upstream of the heating zone such that none of the lengths of the first aerosol generating segment 24 are disposed within the heating zone. The heater assembly 15 comprises a resistive heating element. When the aerosol generating article 10 is fully received within the heating chamber 3, an upstream portion of the hollow tubular cooling element 20 is also received within the heating chamber 3. Such an upstream portion of the hollow tubular cooling element 20 has a length of 11 millimeters. Thus, approximately 28 millimeters of the article 10 is received within the heating chamber 3 and approximately 17 millimeters of the article 10 is located outside of the heating chamber 3. In other words, approximately 17 millimeters of the article 10 protrudes from the device 1 when the article 10 is fully received within the heating chamber 3. Such a length PL of the article 10 protruding from the device 1 is shown in FIG. 2.

[0404] The ventilation zone 30 is arranged to be exposed when the aerosol generating article 10 is fully received within the heating chamber 3.

[0405] In use, the aerosol-generating article 10 is fully received within the heating chamber 3 of the aerosol-generating device 1. The heater assembly 15 is activated by the controller, and the resistive heating element generates heat that is directly transferred to the second aerosol-generating segment 26 disposed within the heating zone. Thereby, an aerosol is generated within the second aerosol-generating substrate. The first aerosol-generating segment 24 that is not located within the heating zone is heated more slowly and at a lower temperature than the second aerosol-generating segment 26. Nevertheless, due to the density and aerosol-forming agent content, the first aerosol-generating substrate also generates an aerosol. When a pressure drop is applied at the downstream end of the aerosol-generating article 10, air is drawn into the air inlet 7, along the air flow channel 5, and into the first aerosol-generating segment 24. The aerosol generated in the first and second aerosol-generating substrates is entrained in the air flow and then passes through the downstream section before exiting the downstream end of the aerosol-generating article.

[0406] Figure 3 shows a second aerosol-generating system 200 according to the present invention. The second aerosol-generating system 200 comprises the same aerosol-generating device 1 as the aerosol-generating device 1 described above in relation to the embodiment of FIG. 2. The second aerosol-generating system 200 further comprises an aerosol-generating article 12. The aerosol-generating article 12 includes all of the same features of the aerosol-generating article 10 of the embodiments of FIGS. 1 and 2.

[0407] The aerosol generating article 12 of FIG. 3 is different from the aerosol generating articles 10 of FIGS. 1 and 2 in that the first aerosol generating segment 24 has a length of 8.5 millimeters and the second aerosol generating segment has a length of 8.5 millimeters. This means that when the aerosol generating article 12 is fully received within the heating chamber 3 of the aerosol generating article 1, the downstream portion of the first aerosol generating segment 24 is disposed within the heating zone of the heater assembly 15. In particular, in the aerosol generating system 200 of FIG. 3, 3.5 millimeters downstream of the first aerosol generating segment 24 is disposed within the heating zone of the heater assembly 15. This means that during use, a portion of the first aerosol generating segment 24 is directly heated by the heater assembly.

[0408] FIG. 4 shows a third aerosol generating article for use in an aerosol generating system according to the present invention. The aerosol generating article 110 shown in FIG. 4 includes all the same features as the aerosol generating article 10 of FIG. 1. However, in the aerosol generating article 110 of FIG. 4, the second aerosol generating segment 126 has a length of 7 millimeters. A third aerosol generating segment 128 is provided between the second aerosol generating segment 126 and the downstream section 14. The third aerosol generating segment 128 has a length of 5 millimeters.

[0409] The third aerosol generating segment 128 includes a third aerosol generating substrate. The third aerosol generating substrate includes a shredded tobacco material containing 15% to 20% by weight of glycerol. The bulk density of the third aerosol generating substrate is about 250 mg per cubic centimeter. The third aerosol generating segment 128 is individually wrapped by a plug wrap (not shown).

[0410] FIG. 5 shows a third aerosol generation system according to the present invention. The third aerosol generation system 300 includes the same aerosol generator 1 as the aerosol generator 1 described above in connection with the embodiment of FIG. 2. The aerosol generation system 300 further includes the aerosol article 110 of FIG. 4.

[0411] As can be seen, when the aerosol article 110 is fully received within the heating chamber 3 of the aerosol generator, both the second and third aerosol generation segments are within the heating zone of the heater assembly 15.

[0412] For the purposes of this specification and the appended claims, unless otherwise indicated, all numbers expressing amounts, quantities, percentages, etc. are to be understood as being modified in all instances by the term "about." Also, all ranges include the disclosed maximum and minimum points, and any intermediate ranges therebetween, whether specifically enumerated herein or not. Thus, in this context, the number A is understood as A ± 10%. In this context, the number A may be considered to include numerical values within the general standard error for the measured value of the characteristic being modified by the number A. The number A may deviate by the percentages recited above in some instances as used in the appended claims, provided that the amount by which A deviates does not substantially affect the basic and novel characteristics of the claimed invention. Also, all ranges include the disclosed maximum and minimum points, and any intermediate ranges therebetween, whether specifically enumerated herein or not.

Claims

1. Aerosol generation system, An aerosol generator for use with an aerosol generating article, A heating chamber for receiving the aerosol generating article, an aerosol generator comprising: a heater assembly disposed along a portion of the heating chamber that defines a heating zone; an aerosol generating article received in the heating chamber of the aerosol generating apparatus, An aerosol generating article comprising a first aerosol generating segment containing a first aerosol generating substrate and a second aerosol generating segment containing a second aerosol generating substrate, wherein the first aerosol generating substrate contains 5 percent to 30 percent glycerol on a dry weight basis, The aerosol generating system, when the aerosol generating article is completely received in the heating chamber of the aerosol generating device, At least 90 percent of the length of the second aerosol generation segment is located within the heating zone. The first aerosol generation segment is located upstream of the second aerosol generation segment. An aerosol generating system in which the length of the first aerosol generating segment is shorter than the length of the second aerosol generating segment.

2. The aerosol generating system according to claim 1, wherein the first aerosol generating segment has an upstream end, and the upstream end of the first aerosol generating segment defines the upstream end of the aerosol generating article.

3. The aerosol generating system according to claim 1 or claim 2, wherein the upstream end of the second aerosol generating segment is in direct contact with the downstream end of the first aerosol generating segment.

4. The aerosol generating system according to claim 1 or claim 2, wherein the first aerosol generating segment has a length of at least 2 millimeters.

5. The aerosol generating system according to claim 1 or claim 2, wherein the first aerosol generating segment has a length of 8 millimeters or less.

6. The aerosol generating system according to claim 1 or claim 2, wherein the second aerosol generating segment has a length of at least 8 millimeters.

7. The aerosol generating system according to claim 1 or claim 2, wherein the second aerosol generating segment has a length of 16 millimeters or less.

8. The aerosol generating system according to claim 1 or claim 2, wherein the heater assembly comprises at least one of a resistance heating element and an induction heating assembly.

9. The aerosol generating system according to claim 1 or claim 2, wherein the first aerosol generating substrate has a first density, and the second aerosol generating substrate has a second density, the second density being greater than the first density.

10. The aerosol generating system according to claim 1 or claim 2, wherein the first aerosol generating substrate and the second aerosol generating substrate each contain at least one aerosol forming body, and the aerosol forming body content of the second aerosol generating substrate is greater than the aerosol forming body content of the first aerosol generating substrate.

11. The aerosol generating system according to claim 1 or claim 2, wherein the second aerosol generating substrate comprises at least one aerosol forming body, and the aerosol forming body content of the second aerosol generating substrate is at least 40 percent by weight on a dry weight basis.

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