Aerosol-generating article having low withdrawal resistance and aerosol-generating film substrate

Abstract

The aerosol-generating article (10) for generating an inhalable aerosol upon heating comprises a rod-shaped aerosol-generating element (12) extending from a mouth end to a distal end and including an aerosol-generating substrate, the aerosol-generating substrate including an aerosol-generating film; and a downstream section (14) located downstream of the aerosol-generating element, the downstream section (14) extending from the downstream end of the aerosol-generating element (10) to the mouth end of the aerosol-generating article (10). The downstream section includes a hollow section (15) defining a longitudinal cavity that provides an unrestricted flow channel. The RTD of the downstream section is less than 25 mmH2O. The aerosol-generating film comprises one or more cellulosic film-forming agents and one or more aerosol formers. The aerosol-generating film has a total aerosol-former content of 46 weight percent or greater.

Description

[Technical Field]

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

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

[0003] Consumables that are solid substrates in the form of gels or films containing nicotine that are heated rather than combusted are known in the art. For example, International Patent Publication No. 2018 / 019543 discloses a thermoreversible gel composition, i.e., a gel that becomes fluid when heated to a melting temperature and solidifies again into a gel at a gelling temperature. The gel is provided in a cartridge housing, and the cartridge may be discarded and replaced when the gel is consumed. WO 2020 / 207733 discloses a consumable product comprising a rod of aerosol-generating substrate having multiple stacked layers of aerosol-generating film. During use, most of the film's components evaporate upon heating, minimizing residue and allowing for easier disposal and reduced environmental impact.

[0004] Numerous prior art documents disclose aerosol generating devices for consuming aerosol-generating articles. Such devices include, for example, electrically heated aerosol generating devices in which aerosols are generated by heat transfer from one or more electric heater elements of the aerosol generating device to an aerosol-generating substrate of the heated aerosol-generating article. For example, an electrically heated aerosol generating device has been proposed that includes an internal heater blade adapted to be inserted into the aerosol-generating substrate. Alternatively, WO 2015 / 176898 proposes an inductively heated aerosol-generating article that includes an aerosol-generating substrate and a susceptor disposed within the aerosol-generating substrate. A further alternative is described in WO 2020 / 115151, which discloses an aerosol-generating article used in combination with an external heating system that includes one or more heating elements disposed around the outer surface of the aerosol-generating article. For example, the external heating element can be provided in the form of a flexible heating foil on a dielectric substrate such as polyimide. The external heating can be resistive or inductive. Summary of the Invention [Problem to be solved by the invention]

[0005] Aerosol-generating articles in which a tobacco-containing substrate is heated rather than combusted present several challenges not faced in conventional smoking articles. First, the tobacco-containing substrate is typically heated to a significantly lower temperature compared to the temperature reached by the combustion front of a conventional cigarette. This can affect nicotine release from the tobacco-containing substrate and nicotine delivery to the consumer. At the same time, if the heating temperature is increased in an attempt to enhance nicotine delivery, the aerosol generated typically needs to be cooled more extensively and more quickly before reaching the consumer. However, technical solutions commonly used to cool mainstream smoke in conventional smoking articles, such as providing a high-filtration efficiency segment at the mouth end of a cigarette, can have undesirable effects in aerosol-generating articles in which a tobacco-containing substrate is heated rather than combusted, as this can reduce nicotine delivery.

[0006] To address one or more of the challenges associated with, inter alia, heating, rather than combustion, of an aerosol-generating substrate to generate an aerosol, a number of aerosol-generating articles have been proposed in which multiple elements are combined, e.g., longitudinally aligned, with an aerosol-generating element comprising the aerosol-generating substrate. By way of example, the aerosol-generating element may be combined with a support element that imparts improved structural strength to the article, an aerosol-cooling element configured to reduce the temperature of the aerosol, a low-filtration mouthpiece element, etc.

[0007] Generally, there is a need for aerosol-generating articles that are easier to use and have improved practicality. Furthermore, it would be desirable to provide aerosol-generating articles that are easier to manufacture, making the entire production chain more sustainable and cost-effective. There is also a need for aerosol-generating articles that are particularly suitable for use in combination with external heating systems, and in particular aerosol-generating articles that have improved aerosol generation and aerosol former delivery. There is also a need to provide such aerosol-generating articles that are easier to dispose of after use or that have a reduced impact on the environment.

[0008] Heating substrates containing cellulose-based materials, particularly hydroxypropyl methylcellulose (HPMC), to excessively high temperatures, e.g., above 300 degrees Celsius, can lead to the generation of off-taste paper and formaldehyde. However, heating such substrates to lower temperatures reduces the level of harmful and potentially harmful compounds (HPHCs) generated while also reducing the aerosolization of the aerosol former and nicotine. In addition, compared to gel-like substrates, which may contain a relatively high weight of aerosol former, film substrates contain a relatively high weight of cellulose-based material, which, together with a lower weight of aerosol former, provides structure to the film. The low weight of aerosol former used in film substrates also reduces the delivery efficiency of the aerosol former and nicotine compared to gel-like substrates. There is a need to provide an aerosol-generating article that includes an aerosol former and a film substrate that enables efficient delivery of nicotine.

[0009] It would therefore be desirable to provide new and improved aerosol-generating articles configured to meet at least one of the above needs. It would further be desirable to provide aerosol-generating articles that enable efficient delivery of nicotine and / or aerosol formers, such as glycerin, while maintaining low levels of HPHCs or even reducing HPHCs. It would further be desirable to provide aerosol-generating articles that can be manufactured efficiently and rapidly, preferably with sufficiently low RTD variability between products. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 shows a schematic cross-sectional side view of an aerosol-generating article according to an embodiment of the present invention. [Figure 2] FIG. 2 shows a schematic cross-sectional side view of another aerosol-generating article according to another embodiment of the present invention. [Figure 3] FIG. 3 shows a schematic cross-sectional side view of another aerosol-generating article according to another embodiment of the present invention. [Figure 4] FIG. 4 shows a schematic cross-sectional side view of another aerosol-generating article according to another embodiment of the present invention. [Figure 5] FIG. 5 shows a schematic cross-sectional side view of another aerosol-generating article according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0011] The present disclosure relates to an aerosol-generating article for generating an inhalable aerosol upon heating, the aerosol-generating article comprising an aerosol-generating element extending from a mouth end to a distal end. The aerosol-generating element may be in the form of a rod. The aerosol-generating element may comprise an aerosol-generating substrate. The aerosol-generating substrate may comprise an aerosol-generating film. The aerosol-generating article may further comprise a downstream section downstream of the aerosol-generating element. The downstream section may extend from the downstream end of the aerosol-generating element to the mouth end of the aerosol-generating article. The downstream section may comprise a hollow section. The hollow section may define a longitudinal cavity that provides an unrestricted flow channel. The RTD of the downstream section may be less than 25 mmH2O. The aerosol-generating film may comprise one or more cellulosic film-forming agents and one or more aerosol formers. The aerosol-generating film may have a total aerosol-former content of 46 weight percent or greater.

[0012] According to the present invention, there is provided an aerosol-generating article for producing an inhalable aerosol upon heating, the aerosol-generating article comprising: a rod-shaped aerosol-generating element extending from a mouth end to a distal end and comprising an aerosol-generating substrate, the aerosol-generating substrate comprising an aerosol-generating film; and a downstream section located downstream of the aerosol-generating element, the downstream section extending from the downstream end of the aerosol-generating element to the mouth end of the aerosol-generating article, the downstream section including a hollow section defining a longitudinal cavity providing an unrestricted flow channel, the RTD of the downstream section being less than 25 mmH2O, the aerosol-generating film comprising one or more cellulosic film-forming agents and one or more aerosol formers, the aerosol-generating film having a total aerosol-former content of 46 weight percent or more.

[0013] The aerosol-generating article according to the present invention therefore provides a novel configuration of the section of the aerosol-generating article downstream of the rod of the aerosol-generating substrate, characterized in that it has an RTD of less than 25 mm H 0. This particularly low RTD downstream of the aerosol-generating substrate is provided in combination with an aerosol-generating substrate in the form of a rod comprising an aerosol-generating film.

[0014] Providing a downstream section with a low RTD has the effect that the majority of the RTD of the aerosol-generating article is provided by the aerosol-generating element itself (e.g., by the rod-shaped aerosol-generating element) and, optionally, by an element located upstream of the aerosol-generating element. The inventors have found that when an aerosol-generating article has an aerosol-generating rod with the above-described shape and has such an RTD distribution along the length of the article, the delivery of aerosol to the consumer can be advantageously optimized, particularly when the article is used in combination with an external heating system.

[0015] Aerosol delivery can be affected, to some extent, by the RTD of the aerosol-generating element itself, because the aerosol generated in the upstream portion of the aerosol-generating element must first flow through the remaining downstream portion of the aerosol-generating element. Thus, controlling the geometry of the aerosol-generating element also allows for more effective control of aerosol delivery, and generally results in more consistent aerosol delivery from aerosol-generating article to aerosol-generating article.

[0016] This is desirable because it simplifies the construction and operation of both the aerosol-generating article and the heating device. Furthermore, it has been found that this allows the substrate to be heated to lower temperatures without compromising the quality and quantity of the aerosol delivered to the consumer.

[0017] Additionally, providing a low RTD downstream of the rod-shaped aerosol-generating element can be achieved by providing a hollow element downstream of the rod-shaped aerosol-generating element, thereby providing a substantially empty volume within the article, promoting aerosol particle nucleation and growth while substantially eliminating the RTD, which can further contribute to improved aerosol generation and delivery compared to existing articles.

[0018] According to the present invention there is provided an aerosol-generating article for generating an inhalable aerosol upon heating.The aerosol-generating article comprises an element comprising an aerosol-generating substrate.

[0019] As used herein, the term "aerosol-generating article" refers to an article that heats an aerosol-generating substrate to generate an inhalable aerosol for delivery to a consumer. As used herein, the term "aerosol-generating substrate" refers to a substrate that has the ability to generate an aerosol by releasing a volatile compound upon heating.

[0020] The aerosol-generating article of the present invention includes an aerosol-generating film or an aerosol-generating substrate in the form of an aerosol-generating film. Such substrates are designed to be heated to relatively low temperatures, i.e., temperatures below approximately 300 degrees Celsius, to minimize the level of formaldehyde generated and avoid the off-taste of paper. Heating a substrate such as an aerosol-generating film to a lower temperature reduces the level of HPHCs generated, but also reduces the aerosolization of the aerosol former and nicotine. In addition, compared to gel-type substrates, the aerosol-generating film contains a relatively high weight of cellulosic material, which, along with a low weight of aerosol former, provides structure to the film. The low weight of aerosol former reduces the delivery efficiency of the aerosol former and nicotine in the film substrate compared to gel-type substrates. The aerosol-generating article of the present invention includes an aerosol-generating film substrate that enables efficient delivery of the aerosol former and nicotine due to its relatively low downstream filtration, i.e., less than about 25 millimeters of water, and low RTD, compared to conventional aerosol-generating articles.

[0021] A conventional cigarette is lit when a user applies a flame to one end of the cigarette and draws air through the other end. Localized heat provided by the flame and oxygen in the air drawn through the cigarette ignites the end of the cigarette, and the resulting combustion produces inhalable smoke. In contrast, in heated aerosol-generating articles, the aerosol is generated by heating a flavor-generating substrate (such as tobacco). Known heated aerosol-generating articles include, for example, electrically heated aerosol-generating articles and aerosol-generating articles in which the aerosol is generated by heat transfer from a combustible fuel element or heat source to a physically separated aerosol-forming material. For example, the aerosol-generating article according to the present invention finds particular application in aerosol-generating systems comprising an electrically heated aerosol generator having an internal heater blade adapted to be inserted into a rod of the aerosol-generating substrate. Aerosol-generating articles of this type are described in the prior art, for example, in EP 0 822 670.

[0022] As used herein, the term "aerosol-generating device" refers to a device comprising a heater element that interacts with an aerosol-generating substrate of an aerosol-generating article to generate an aerosol. During use, volatile compounds are released from the aerosol-generating film by heat transfer and are entrained in the air drawn through the aerosol-generating article. As the released compounds cool, they condense to form an aerosol, which is inhaled by the consumer.

[0023] The aerosol-generating element may be in the form of a rod comprising or made from an aerosol-generating substrate. As used herein in connection with the present invention, the term "rod" is used to denote a generally cylindrical element of substantially circular, oval or elliptical cross section.

[0024] As used herein, the term "longitudinal" refers to a direction corresponding to the major longitudinal axis of the aerosol-generating article extending between the upstream and downstream ends of the aerosol-generating article. As used herein, the terms "upstream" and "downstream" refer to the relative positions of elements (or portions of elements) of the aerosol-generating article with respect to the direction in which aerosol is transported through the aerosol-generating article during use.

[0025] As used herein, the term "upstream end of the aerosol-generating article" refers to the distal end of the aerosol-generating article.

[0026] As used herein, the term "downstream end of the aerosol-generating article" refers to the mouth end of the aerosol-generating article.

[0027] During use, air is drawn longitudinally through the aerosol-generating article. The term "transverse" refers to a direction perpendicular to the longitudinal axis. Any reference to a "cross section" of an aerosol-generating article or a component of an aerosol-generating article refers to a transverse cross section, unless otherwise specified.

[0028] The term "length" refers to the dimension of a component of an aerosol-generating article in its longitudinal direction. For example, it may be used to refer to the dimension of a rod or elongated tubular element in its longitudinal direction.

[0029] As used herein, the term "film" is used to describe a solid, layered element having a thickness that is less than its width or length.

[0030] The film may be self-supporting, that is, it may have cohesive and mechanical properties such that it can be separated from a support surface, even when obtained by casting a film-forming formulation onto the support surface.

[0031] Alternatively, the film may be placed on a support or sandwiched between other materials, which may enhance the mechanical stability of the film. The "thickness" of the aerosol-generating film of an aerosol-generating article according to the present invention corresponds to the smallest distance measured between opposing substantially parallel surfaces of the film.

[0032] Unless otherwise specified, the resistance to draw (RTD) of a component or aerosol-generating article is measured in accordance with ISO 6565-2015. RTD refers to the pressure required to pump air through the entire length of the component. The terms "pressure drop" or "draw resistance" of a component or article can also refer to "resistance to draw." These terms generally refer to measurements in accordance with ISO 6565-2015 being performed successfully under test at a temperature of about 22 degrees Celsius, a pressure of about 101 kPa (about 760 Torr), and a relative humidity of about 60%, with a volumetric flow rate of about 17.5 milliliters per second at the output or downstream end of the component being measured.

[0033] The aerosol-generating article further comprises a downstream section located downstream of the rod of the aerosol-generating substrate. As will become apparent from the following description of different embodiments of the aerosol-generating article of the present invention, the downstream section may comprise one or more downstream elements. The downstream section comprises a hollow section and, optionally, a mouthpiece section. The mouthpiece section comprises one or more mouthpiece filter segments. The mouthpiece section extends from the upstream end of the most upstream mouthpiece filter segment to the mouth end of the aerosol-generating article.

[0034] The downstream section includes a hollow section defining a longitudinal cavity that provides an unrestricted flow channel. In one embodiment, the downstream section may include a hollow section between the mouth end of the aerosol-generating article and the aerosol-generating element, the hollow section extending all the way to the mouth end of the aerosol-generating article. In another embodiment, the downstream section may include a hollow section between the aerosol-generating element and the mouthpiece section. The hollow section may comprise a hollow tubular element.

[0035] As used herein, the term "hollow tubular segment" or "hollow tubular element" refers to a generally elongated element that defines a lumen or airflow passage along its longitudinal axis. In particular, the term "tubular" is used hereinafter with reference to an element or segment that has a substantially cylindrical cross-section and defines at least one airflow conduit that establishes uninterrupted fluid communication between the upstream end of the tubular element or segment and the downstream end of the tubular element or segment. However, it will be appreciated that alternative shapes (e.g., alternative cross-sectional shapes) of the tubular element or segment may be possible.

[0036] As used herein, the term "elongated" means that an element has a length dimension that is greater than its width or diameter dimension, for example, more than twice its width or diameter dimension.

[0037] In the context of the present invention, a hollow tubular segment or element provides an unrestricted flow channel. This means that the hollow tubular segment or element provides a negligible resistance to withdrawal (RTD). The term "negligible RTD" is used to describe an RTD of less than 1 mmH2O per 10 millimeters of hollow tubular segment or element, preferably less than 0.4 mmH2O per 10 millimeters of hollow tubular segment or element, and more preferably less than 0.1 mmH2O per 10 millimeters of hollow tubular segment or element.

[0038] Therefore, the flow channels should not include any components that would obstruct the longitudinal air flow. Preferably, the flow channels are substantially empty.

[0039] Herein, a "hollow tubular segment" or "hollow tubular element" may also be referred to as a "hollow tube" or "hollow tube segment."

[0040] In some embodiments, the aerosol-generating article may include a ventilation zone located along the downstream section. More particularly, the aerosol-generating article may include a ventilation zone located along the hollow tubular element. In this manner, fluid communication is established between the flow channel defined therein by the hollow tubular element and the external environment.

[0041] The aerosol-generating article further comprises an upstream section at a location upstream of the rod of aerosol-generating substrate. The upstream section may comprise one or more upstream elements. In some embodiments, the upstream section may comprise an upstream element located immediately upstream of the aerosol-generating element.

[0042] As briefly described above, an aerosol-generating article according to the present invention comprises an element comprising an aerosol-generating substrate.

[0043] In some embodiments, the aerosol-generating element may be provided in the form of a rod comprising an aerosol-generating substrate. As an example, the aerosol-generating element may comprise a rod of aerosol-generating substrate surrounded by a wrapper.

[0044] The element comprising the aerosol-generating substrate can have a length of at least about 5 millimeters. Preferably, the element comprising the aerosol-generating substrate has a length of at least about 7 millimeters. More preferably, the element comprising the aerosol-generating substrate has a length of at least about 10 millimeters. In a particularly preferred embodiment, the element comprising the aerosol-generating substrate has a length of at least about 12 millimeters.

[0045] The element comprising the aerosol-generating substrate may have a length of up to about 80 millimeters. Preferably, the element comprising the aerosol-generating substrate has a length of about 65 millimeters or less. More preferably, the element comprising the aerosol-generating substrate has a length of about 60 millimeters or less. Even more preferably, the element comprising the aerosol-generating substrate has a length of about 55 millimeters or less.

[0046] In particularly preferred embodiments, the element comprising the aerosol-generating substrate has a length of about 50 millimeters or less, more preferably about 35 millimeters or less, even more preferably about 25 millimeters or less, In particularly preferred embodiments, the element comprising the aerosol-generating substrate has a length of about 20 millimeters or less, or about 15 millimeters or less.

[0047] In some embodiments, the element comprising the aerosol-generating substrate has a length of about 5 millimeters to about 60 millimeters, preferably about 6 millimeters to about 60 millimeters, more preferably about 7 millimeters to about 60 millimeters, even more preferably about 10 millimeters to about 60 millimeters, and most preferably about 12 millimeters to about 60 millimeters. In another embodiment, the element comprising the aerosol-generating substrate has a length of about 5 millimeters to about 55 millimeters, preferably about 6 millimeters to about 55 millimeters, more preferably about 7 millimeters to about 55 millimeters, even more preferably about 10 millimeters to about 55 millimeters, and most preferably about 12 millimeters to about 55 millimeters. In a further embodiment, the element comprising the aerosol-generating substrate has a length of about 5 millimeters to about 50 millimeters, preferably about 6 millimeters to about 50 millimeters, more preferably about 7 millimeters to about 50 millimeters, even more preferably about 10 millimeters to about 50 millimeters, and most preferably about 12 millimeters to about 50 millimeters.

[0048] In some particularly preferred embodiments, the element comprising the aerosol-generating substrate has a length of about 5 mm to about 30 mm, preferably about 6 mm to about 30 mm, more preferably about 7 mm to about 30 mm, and even more preferably about 10 mm to about 30 mm. In other particularly preferred embodiments, the element comprising the aerosol-generating substrate has a length of about 5 mm to about 20 mm, preferably about 6 mm to about 20 mm, more preferably about 7 mm to about 20 mm, and even more preferably about 10 mm to about 20 mm. In even more particularly preferred embodiments, the element comprising the aerosol-generating substrate has a length of about 5 mm to about 15 mm, preferably about 7 mm to about 20 mm, more preferably about 9 mm to about 16 mm, and even more preferably about 10 mm to about 15 mm.

[0049] The rod-shaped element comprising the aerosol-generating substrate preferably has an outer diameter approximately equal to the outer diameter of the aerosol-generating article.

[0050] Preferably, the element comprising the aerosol-generating substrate has an outer diameter of at least about 5 millimeters. More preferably, the element comprising the aerosol-generating substrate has an outer diameter of at least about 6 millimeters. Even more preferably, the element comprising the aerosol-generating substrate has an outer diameter of at least about 7 millimeters.

[0051] Preferably, the element comprising the aerosol-generating substrate has an outer diameter of about 12 millimeters or less. More preferably, the element comprising the aerosol-generating substrate has an outer diameter of about 10 millimeters or less. Even more preferably, the element comprising the aerosol-generating substrate has an outer diameter of about 8 millimeters or less.

[0052] It has generally been observed that the smaller the diameter of the rod-shaped element comprising the aerosol-generating substrate, the lower the temperature required to raise the core temperature of the aerosol-generating element, and a sufficient amount of vaporized species will be released from the aerosol-generating substrate to form the desired amount of aerosol. At the same time, without wishing to be bound by any theory, it is understood that the smaller the diameter of the rod-shaped element comprising the aerosol-generating substrate, the faster the heat supplied to the aerosol-generating article can penetrate into the entire volume of the aerosol-forming substrate. Nevertheless, if the diameter of the rod-shaped element comprising the aerosol-generating substrate is too small, the amount of available aerosol-forming substrate will decrease, resulting in an unfavorable ratio of the volume to the surface of the aerosol-generating substrate.

[0053] The diameter of the rod-shaped element comprising the aerosol-generating substrate within the range described herein is particularly advantageous in terms of the balance between energy consumption and aerosol delivery. This advantage is particularly realized when an aerosol-generating article comprising a rod comprising an aerosol-generating substrate having a diameter described herein is used in combination with an external heater disposed around the outer surface of the aerosol-generating article. Under such operating conditions, it has been observed that less thermal energy is required to achieve a sufficiently high temperature at the core of the rod comprising the aerosol-generating substrate, and at the core of the article in general. This allows the desired target temperature at the core of the aerosol-generating substrate to be achieved within a desirably shortened time frame and with lower energy consumption when operating at a lower temperature.

[0054] In some embodiments, the element comprising the aerosol-generating substrate has an outer diameter of about 5 mm to about 12 mm, preferably about 6 mm to about 12 mm, and more preferably about 7 mm to about 12 mm. In other embodiments, the element comprising the aerosol-generating substrate has an outer diameter of about 5 mm to about 12 mm, preferably about 6 mm to about 10 mm, and more preferably about 7 mm to about 10 mm. In further embodiments, the element comprising the aerosol-generating substrate has an outer diameter of about 5 mm to about 8 mm, preferably about 6 mm to about 8 mm, and more preferably about 7 mm to about 8 mm.

[0055] In a particularly preferred embodiment, the element comprising the aerosol-generating substrate has an outer diameter of less than about 7.5 millimeters. By way of example, the element comprising the aerosol-generating substrate may have an outer diameter of about 7.2 millimeters.

[0056] The length to diameter ratio of the aerosol-generating element is at least about 0.50. Preferably, the length to diameter ratio of the aerosol-generating element is at least about 0.75. More preferably, the length to diameter ratio of the aerosol-generating element is at least about 1.00. Even more preferably, the length to diameter ratio of the aerosol-generating element is at least about 1.25.

[0057] The length-to-diameter ratio of the aerosol-generating element is about 3.00 or less. Preferably, the length-to-diameter ratio of the aerosol-generating element is about 2.75 or less. More preferably, the length-to-diameter ratio of the aerosol-generating element is about 2.50 or less. Even more preferably, the length-to-diameter ratio of the aerosol-generating element is about 2.25 or less.

[0058] More particularly, in aerosol-generating articles according to the present invention, the length-to-diameter ratio of the aerosol-generating element is from about 0.50 to about 3.00.

[0059] The length-to-diameter ratio of the aerosol-generating element is preferably about 0.75 to about 3.00, more preferably about 1.00 to about 3.00, and even more preferably about 1.25 to about 3.00.

[0060] In other embodiments, the length-to-diameter ratio of the aerosol-generating element may be about 0.50 to about 2.75. Preferably, the length-to-diameter ratio of the aerosol-generating element is about 0.75 to about 2.75. More preferably, the length-to-diameter ratio of the aerosol-generating element is about 1.00 to about 2.75. Even more preferably, the length-to-diameter ratio of the aerosol-generating element is about 1.25 to about 2.75.

[0061] In further embodiments, the length-to-diameter ratio of the aerosol-generating element may be from about 0.50 to about 2.50. Preferably, the length-to-diameter ratio of the aerosol-generating element is from about 0.75 to about 2.50. More preferably, the length-to-diameter ratio of the aerosol-generating element is from about 1.00 to about 2.50. Even more preferably, the length-to-diameter ratio of the aerosol-generating element is from about 1.25 to about 2.50.

[0062] In still further embodiments, the length-to-diameter ratio of the aerosol-generating element may be from about 0.50 to about 2.25. Preferably, the length-to-diameter ratio of the aerosol-generating element is from about 0.75 to about 2.25. More preferably, the length-to-diameter ratio of the aerosol-generating element is from about 1.00 to about 2.25. Even more preferably, the length-to-diameter ratio of the aerosol-generating element is from about 1.25 to about 2.25.

[0063] In particularly preferred embodiments, the length to diameter ratio of the aerosol-generating element may be at least about 1.30, more preferably about 1.40, and even more preferably about 1.50.

[0064] In particularly preferred embodiments, the length to diameter ratio of the aerosol-generating element may be about 2.00 or less, more preferably about 1.90 or less, and even more preferably about 1.80 or less.

[0065] In some embodiments, the length-to-diameter ratio of the aerosol-generating element is preferably about 1.30 to about 2.00, more preferably about 1.40 to about 2.00, and even more preferably about 1.50 to about 2.00. In other embodiments, the length-to-diameter ratio of the aerosol-generating element is preferably about 1.30 to about 1.90, more preferably about 1.40 to about 1.70, and even more preferably about 1.50 to about 1.90. In further embodiments, the length-to-diameter ratio of the aerosol-generating element is preferably about 1.30 to about 1.80, more preferably about 1.40 to about 1.80, and even more preferably about 1.50 to about 1.80.

[0066] The ratio of the length of the aerosol-generating element to the total length of the aerosol-generating article can be at least about 0.10. Preferably, the ratio of the length of the aerosol-generating element to the total length of the aerosol-generating article is at least about 0.15. More preferably, the ratio of the length of the aerosol-generating element to the total length of the aerosol-generating article is at least about 0.20. Even more preferably, the ratio of the length of the aerosol-generating element to the total length of the aerosol-generating article is at least about 0.25.

[0067] Typically, the ratio of the length of the aerosol-generating element to the total length of the aerosol-generating article can be about 0.60 or less. Preferably, the ratio of the length of the aerosol-generating element to the total length of the aerosol-generating article is about 0.50 or less. More preferably, the ratio of the length of the aerosol-generating element to the total length of the aerosol-generating article is about 0.45 or less. Even more preferably, the ratio of the length of the aerosol-generating element to the total length of the aerosol-generating article is about 0.40 or less. In particularly preferred embodiments, the ratio of the length of the aerosol-generating element to the total length of the aerosol-generating article is about 0.35 or less, and most preferably about 0.30 or less.

[0068] In some embodiments, the ratio of the length of the aerosol-generating element to the total length of the aerosol-generating article is about 0.10 to about 0.45, preferably about 0.15 to about 0.45, more preferably about 0.20 to about 0.45, and even more preferably about 0.25 to about 0.45. In other embodiments, the ratio of the length of the aerosol-generating element to the total length of the aerosol-generating article is about 0.10 to about 0.40, preferably about 0.15 to about 0.40, more preferably about 0.20 to about 0.40, and even more preferably about 0.25 to about 0.40. In other embodiments, the ratio of the length of the aerosol-generating element to the total length of the aerosol-generating article is about 0.10 to about 0.35, preferably about 0.15 to about 0.35, more preferably about 0.20 to about 0.35, and even more preferably about 0.25 to about 0.35. In yet another embodiment, the ratio of the length of the aerosol-generating element to the total length of the aerosol-generating article is from about 0.10 to about 0.30, preferably from about 0.15 to about 0.30, more preferably from about 0.20 to about 0.30, and even more preferably from about 0.25 to about 0.30.

[0069] In a particularly preferred embodiment, the ratio of the length of the aerosol-generating element to the overall length of the aerosol-generating article is about 0.27.

[0070] Preferably, the aerosol-generating element comprises a rod-shaped element of aerosol-generating substrate having a substantially uniform cross-section along the length of the element, and it is particularly preferred that the rod-shaped element comprising the aerosol-generating substrate has a substantially circular cross-section.

[0071] As described in more detail below, aerosol-generating articles according to the present invention comprise a downstream section that includes a hollow section. The downstream section may extend from the downstream end of the aerosol-generating element to the mouth end of the aerosol-generating article.

[0072] In the aerosol-generating article according to the present invention, the downstream section includes a hollow section and, optionally, a mouthpiece section. The hollow section defines a longitudinal cavity that provides an unrestricted flow channel. The hollow section may include a first hollow tubular element that defines a longitudinal cavity that provides an unrestricted flow channel. The first hollow tubular element may be immediately downstream of the aerosol-generating element or may abut the downstream end of the aerosol-generating element. The hollow section may include one or more hollow tubular elements that define a longitudinal cavity that provides an unrestricted flow channel. The hollow section, the first hollow tubular element, or the one or more hollow tubular elements may extend entirely from the downstream end of the aerosol-generating element to the mouth end of the aerosol-generating article. Alternatively, the mouthpiece section may be present such that the hollow section is an intermediate hollow section between the aerosol-generating element and the mouthpiece section.

[0073] The hollow section may further include a second hollow tubular element. The hollow section may include first and second hollow tubular elements defining a longitudinal cavity that provides an unrestricted flow channel. The first hollow tubular element may be immediately downstream of the aerosol generation element or may abut the aerosol generation element. The support element may be immediately downstream of the aerosol generation element or may abut the aerosol generation element. The aerosol-cooling element may include or be in the form of a second hollow tubular element. The second hollow tubular element may be immediately downstream of the first hollow tubular element or may abut the first hollow tubular element. The aerosol-cooling element may be immediately downstream of and abut the support element.

[0074] When a mouthpiece section is present, the hollow section is an intermediate hollow section between the mouthpiece section and the aerosol-generating element. When present, the mouthpiece section extends from the upstream end of the most upstream mouthpiece filter segment to the oral end of the aerosol-generating article. The mouthpiece section may be downstream of the hollow tubular element or one or more hollow tubular elements. The mouthpiece section may abut the hollow tubular element. The mouthpiece section may be located downstream of both the first hollow tubular element or support element and the second hollow tubular element or aerosol-cooling element. It is particularly preferred that the mouthpiece section be located immediately downstream of the second hollow tubular element or aerosol-cooling element. As an example, the upstream end of the mouthpiece filter segment may abut the downstream end of the aerosol-cooling element.

[0075] The length L1 of the downstream section may be defined as the distance between the downstream end of the aerosol-generating element and the mouth end of the aerosol-generating article. The hollow section may extend from the downstream end of the aerosol-generating element to the upstream end of the mouthpiece section, or from the downstream end of the aerosol-generating element to the mouth end of the aerosol-generating article if no mouthpiece section is present. The length L2 of the hollow section may be defined as the distance from the upstream end of the most upstream hollow tubular element containing the hollow section to the downstream end of the most downstream hollow tubular element containing the hollow section. The hollow tubular element may be located immediately downstream of the aerosol-generating element or may abut the aerosol-generating element. The length L2 of the hollow section may be defined as the distance between the downstream end of the aerosol-generating element and the upstream end of the mouthpiece section, or from the downstream end of the aerosol-generating element to the mouth end of the aerosol-generating article if no mouthpiece section is present. In embodiments where L1 is equal to L2, the hollow section may extend all the way to the mouth end of the aerosol-generating article. In embodiments where L2 is less than L1, the hollow section may extend from the downstream end of the aerosol generation element to the upstream end of the mouthpiece section.

[0076] The downstream section may have any length L1. The downstream section may have a length of at least about 10 millimeters. For example, the downstream section may have a length of at least about 15 millimeters, at least about 20 millimeters, at least about 25 millimeters, or at least about 30 millimeters.

[0077] Providing a downstream section having a length greater than the above values ​​advantageously allows space for the aerosol to cool and condense before reaching the consumer, and also ensures that the user is away from the heating element when the aerosol-generating article is used in conjunction with an aerosol-generating device.

[0078] The downstream section may have a length of about 60 millimeters or less. For example, the downstream section may have a length of about 50 millimeters or less, about 55 millimeters or less, about 40 millimeters or less, or about 35 millimeters or less.

[0079] The downstream section may have a length of about 10 millimeters to about 60 millimeters, about 15 millimeters to about 50 millimeters, about 20 millimeters to about 55 millimeters, about 25 millimeters to about 40 millimeters, or about 27 millimeters to about 35 millimeters. For example, the downstream section may have a length of about 33 millimeters or about 28 millimeters.

[0080] The ratio of the length of the downstream section to the length of the element comprising the aerosol-generating substrate may be from about 1.00 to about 4.50.

[0081] Preferably, the ratio of the length of the downstream section to the length of the aerosol-generating element is at least about 1.50, more preferably at least about 2.00, and even more preferably at least about 2.30. In preferred embodiments, the ratio of the length of the downstream section to the length of the aerosol-generating element is less than about 4.00, more preferably less than about 3.50, and even more preferably less than about 3.00.

[0082] In some embodiments, the ratio of the length of the downstream section to the length of the aerosol-generating element is from about 1.50 to about 4.00, preferably from about 2.00 to about 3.50, and more preferably from about 2.30 to about 3.00.

[0083] In a particularly preferred embodiment, the ratio of the length of the downstream section to the length of the aerosol-generating element is about 2.33, hi another embodiment, the ratio of the length of the downstream section to the length of the aerosol-generating element is about 2.75.

[0084] The ratio of the length of the downstream section to the overall length of the aerosol-generating article may be from about 0.10 to about 0.90.

[0085] The ratio of the length of the downstream section to the overall length of the aerosol-generating article is preferably at least about 0.25, more preferably at least about 0.50, and is preferably less than about 0.85, more preferably less than about 0.90.

[0086] In some embodiments, the ratio of the length of the downstream section to the total length of the aerosol-generating article is preferably about 0.25 to about 0.90, more preferably about 0.50 to about 0.90. In some embodiments, the ratio of the length of the downstream section to the total length of the aerosol-generating article is preferably about 0.25 to about 0.85, more preferably about 0.50 to about 0.85.

[0087] In a particularly preferred embodiment, the ratio of the length of the downstream section to the overall length of the aerosol-generating article is about 0.62, hi another embodiment, the ratio of the length of the downstream section to the overall length of the aerosol-generating article is about 0.73.

[0088] The length of the downstream section may consist of the sum of the lengths of the individual components that form the downstream section.

[0089] As briefly discussed above, in aerosol-generating articles according to the present invention, the RTD of the downstream section is less than about 25 mmH2O. Preferably, the RTD of the downstream section may be about 15 mmH2O or less, or about 10 mH2O or less, or about 1 mH2O or less, or about 0 mH2O. The RTD of the downstream section may be greater than about 10 mmH2O, or between about 10 mmH2O and 25 mmH2O, with between about 10 mmH2O and 15 mmH2O even more preferred. The RTD of the downstream section is also discussed in more detail below.

[0090] The downstream section may provide an unobstructed airflow path from the downstream end of the aerosol-generating substrate to the downstream end of the downstream section.

[0091] The unobstructed airflow path from the downstream end of the aerosol-generating substrate to the downstream end of the downstream section has a minimum diameter of about 0.5 millimeters. For example, the unobstructed airflow path can have a minimum diameter of 1 millimeter, 2 millimeters, 3 millimeters, or 5 millimeters.

[0092] The downstream section may include a hollow section. The hollow section may include a hollow tube element, or one or more hollow tube elements. The hollow section does not substantially contribute to the RTD of the downstream section. The hollow tube element does not substantially contribute to the RTD of the downstream section.

[0093] As described below, the mouthpiece section may contribute minimally to the RTD of the downstream section.

[0094] The provision of a hollow tube element can advantageously provide a desired overall length for the aerosol-generating article without unacceptably increasing the resistance to withdrawal.

[0095] The hollow section may extend from the downstream end of the downstream section to the upstream end of the downstream section. In other words, the hollow section may occupy the entire length of the downstream section. That is, the length L1 of the downstream section is equal to the length L2 of the hollow section as defined above. In this case, it will be understood that the above lengths and length ratios for the downstream section are equally applicable to the length of the hollow section.

[0096] The hollow section may have any length L2. The hollow section may have a length of at least about 10 millimeters. For example, the hollow section may have a length of at least about 15 millimeters, at least about 20 millimeters, at least about 25 millimeters, or at least about 30 millimeters.

[0097] Providing a hollow section with a length greater than the above values ​​advantageously allows space for the aerosol to cool and condense before reaching the consumer, and also ensures that the user is away from the heating element when the aerosol-generating article is used in conjunction with an aerosol-generating device.

[0098] The hollow section may have a length of about 60 millimeters or less. For example, the hollow section may have a length of about 50 millimeters or less, about 55 millimeters or less, about 40 millimeters or less, or about 35 millimeters or less.

[0099] The hollow section may have a length of about 10 millimeters to about 60 millimeters, about 15 millimeters to about 50 millimeters, about 15 millimeters to about 55 millimeters, about 15 millimeters to about 40 millimeters, or about 27 millimeters to about 35 millimeters. For example, the hollow section may have a length of about 16 millimeters, about 28 millimeters, or about 33 millimeters.

[0100] The hollow section may extend all the way from the downstream end of the aerosol-generating element to the mouth end of the aerosol-generating article and may have a length of at least 25 millimeters.

[0101] The ratio of the length of the hollow section to the length of the downstream section can be from about 0.30 to about 1.00.

[0102] Preferably, the ratio of the length of the hollow section to the length of the downstream section is at least about 0.40, more preferably at least about 0.50. The ratio of the length of the hollow section to the length of the downstream section may be at least about 1.00.

[0103] In some embodiments, the ratio of the length of the hollow section to the length of the downstream section is preferably from about 0.40 to about 1.00, more preferably from about 0.50 to about 1.00.

[0104] In a particularly preferred embodiment, the ratio of the length of the hollow section to the length of the downstream section is about 0.57. In another particularly preferred embodiment, the ratio of the length of the hollow section to the length of the downstream section is about 1.00.

[0105] The ratio of the length of the hollow section to the length of the element comprising the aerosol-generating substrate may be from about 1.00 to about 4.50.

[0106] Preferably, the ratio of the length of the hollow section to the length of the aerosol-generating element is at least about 1.10, more preferably at least about 1.20, and even more preferably at least about 1.30. In preferred embodiments, the ratio of the length of the hollow section to the length of the aerosol-generating element is less than about 4.00, more preferably less than about 3.50, and even more preferably less than about 3.00.

[0107] In some embodiments, the ratio of the length of the hollow section to the length of the aerosol-generating element is from about 1.10 to about 4.00, preferably from about 1.20 to about 3.50, and more preferably from about 1.30 to about 3.00.

[0108] In particularly preferred embodiments, the ratio of the length of the hollow section to the length of the aerosol-generating element is about 1.33. In particularly preferred embodiments, the ratio of the length of the hollow section to the length of the aerosol-generating element is about 2.33. In particularly preferred embodiments, the ratio of the length of the hollow section to the length of the aerosol-generating element is about 2.75.

[0109] The ratio of the length of the hollow section to the overall length of the aerosol-generating article may be from about 0.10 to about 0.90.

[0110] The ratio of the length of the hollow section to the overall length of the aerosol-generating article is preferably at least about 0.25, more preferably at least about 0.30.The ratio of the length of the downstream section to the overall length of the aerosol-generating article is preferably less than about 0.80, more preferably less than about 0.90.

[0111] In some embodiments, the ratio of the length of the hollow section to the total length of the aerosol-generating article is preferably from about 0.10 to about 0.90, more preferably from about 0.10 to about 0.80. In some embodiments, the ratio of the length of the hollow section to the total length of the aerosol-generating article is preferably from about 0.25 to about 0.90, more preferably from about 0.25 to about 0.80.

[0112] In particularly preferred embodiments, the ratio of the length of the hollow section to the overall length of the aerosol-generating article is about 0.36. In particularly preferred embodiments, the ratio of the length of the hollow section to the overall length of the aerosol-generating article is about 0.62. In particularly preferred embodiments, the ratio of the length of the hollow section to the overall length of the aerosol-generating article is about 0.75.

[0113] The hollow section may include a hollow tubular element defining a longitudinal cavity that provides an unrestricted flow channel.

[0114] The hollow pipe can extend from the downstream end of the downstream section to the upstream end of the downstream section. In other words, the entire length of the downstream section can be occupied by the hollow pipe element. The ratio of the length of the hollow pipe element to the length of the downstream section can be about 1.00. In this case, it will be understood that the lengths and length ratios described above for the downstream section are equally applicable to the length of the hollow pipe element.

[0115] The hollow pipe can extend from the downstream end of the hollow section to the upstream end of the hollow section. In other words, the entire length of the hollow section can be occupied by a hollow pipe element. The ratio of the length of the hollow pipe element to the length of the hollow section can be at least about 1.00. In this case, it will be understood that the lengths and length ratios described with respect to the hollow section are equally applicable to the length of the hollow pipe element.

[0116] The hollow tubular element may abut the downstream end of the aerosol-generating article.

[0117] The hollow tubular element may be spaced apart from the downstream end of the aerosol-generating article, in which case there may be an empty space between the downstream end of the aerosol-generating article and the upstream end of the hollow tubular element.

[0118] The hollow tube element may have an inner diameter. The hollow tube element may have a constant inner diameter along the length of the hollow tube element. The inner diameter of the hollow tube element may vary along the length of the hollow tube element.

[0119] The hollow tube element may have an inner diameter of at least about 2 millimeters. For example, the hollow tube element may have an inner diameter of at least about 4 millimeters, at least about 5 millimeters, or at least about 7 millimeters.

[0120] Providing a hollow tube element with an inner diameter as set out above may advantageously provide the hollow tube element with sufficient stiffness and strength.

[0121] The hollow tube element may have an inner diameter of about 10 millimeters or less. For example, the hollow tube element may have an inner diameter of about 9 millimeters or less, about 8 millimeters or less, or about 7.5 millimeters or less.

[0122] Providing a hollow tubular element with an inner diameter as set out above may advantageously reduce the resistance to withdrawal of the hollow tubular element.

[0123] The hollow tube element may have an inner diameter of about 2 millimeters to about 10 millimeters, about 4 millimeters to about 9 millimeters, about 5 millimeters to about 8 millimeters, or about 7 millimeters to about 7.5 millimeters.

[0124] The hollow tube element may have an inner diameter of about 7.1 millimeters.

[0125] The ratio of the inner diameter of the hollow tube element to the outer diameter of the hollow tube element may be at least about 0.80. For example, the ratio of the inner diameter of the hollow tube element to the outer diameter of the hollow tube element may be at least about 0.85, at least about 0.90, or at least about 0.95.

[0126] The ratio of the inner diameter of the hollow tube element to the outer diameter of the hollow tube element may be about 0.99 or less. For example, the ratio of the inner diameter of the hollow tube element to the outer diameter of the hollow tube element may be about 0.98 or less.

[0127] The ratio of the inner diameter of the hollow tubular element to the outer diameter of the hollow tubular element may be about 0.97.

[0128] By providing a relatively large inner diameter, the resistance to pulling out the hollow tubular element can be advantageously reduced.

[0129] The lumen of the hollow tubular element may have any cross-sectional shape. The lumen of the hollow tubular element may have a circular cross-sectional shape.

[0130] The hollow tubular element may be formed from any material. For example, the hollow tube may comprise cellulose acetate tow. When the hollow tubular element comprises cellulose acetate tow, the hollow tubular element may have a thickness of about 0.1 millimeter to about 1 millimeter. The hollow tubular element may have a thickness of about 0.5 millimeters.

[0131] When the hollow tubular element comprises cellulose acetate tow, the cellulose acetate tow may have a denier per filament of from about 2 to about 4 and a total denier of from about 25 to about 40.

[0132] The hollow tubular element may comprise paper. The hollow tubular element may comprise at least one layer of paper. The paper may be very stiff paper. The paper may be crimped paper, such as crimped heat-resistant paper or crimped parchment paper. The paper may be cardboard. The hollow tubular element may be a paper tube. The hollow tubular element may be a tube formed from spirally wound paper. The hollow tubular element may be formed from multiple layers of paper. The paper may have a basis weight of at least about 50 grams per square meter, at least about 60 grams per square meter, at least about 70 grams per square meter, or at least about 90 grams per square meter.

[0133] When the tubular element comprises paper, the paper may have a thickness of at least about 50 micrometers. For example, the paper may have a thickness of at least about 70 micrometers, at least about 90 micrometers, or at least about 100 micrometers.

[0134] The hollow tubular element may comprise a polymer. For example, the hollow tubular element may comprise a polymeric film. The polymeric film may comprise a cellulose film. The hollow tubular element may comprise low density polyethylene (LDPE) or polyhydroxyalkanoate (PHA) fibers.

[0135] Preferably, the hollow tubular element is adapted to generate an RTD of between approximately 0 millimeters of HO (about 0 Pa) and approximately 20 millimeters of HO (about 100 Pa), more preferably between approximately 0 millimeters of HO (about 0 Pa) and approximately 10 millimeters of HO (about 100 Pa). Thus, the hollow tubular element preferably does not contribute to the overall RTD of the aerosol-generating article.

[0136] The hollow section may extend from the downstream end of the downstream section to the upstream end of the mouthpiece section. In other words, only a portion of the length of the downstream section may be occupied by the hollow section, with the remaining portion being occupied by the mouthpiece section. That is, the length L1 of the downstream section is greater than the length L2 of the hollow section as defined above.

[0137] One or more hollow tubes may extend from the downstream end of the downstream section to the upstream end of the mouthpiece section, in other words the entire length of the hollow section may be occupied by one or more hollow tube elements.

[0138] The hollow section may be an intermediate hollow section. Preferably, when the hollow section is an intermediate hollow section, the overall length of the hollow section is about 18 millimeters or less, more preferably about 17 millimeters or less, more preferably 16 millimeters or less.

[0139] According to one embodiment of the present invention, the hollow section may include a first hollow tubular element or support element located immediately downstream of the aerosol generation element, preferably abutting the aerosol generation element. The mouthpiece section is optionally located downstream of the support element. The hollow section may further include a second hollow tubular element or aerosol cooling element located immediately downstream of the support element, preferably abutting the support element. The mouthpiece section is optionally located immediately downstream of the aerosol cooling element. The mouthpiece section includes one or more mouthpiece filter segments. Preferably, the mouthpiece section includes a single mouthpiece filter segment. As an example, the upstream end of the mouthpiece filter segment may abut the downstream end of the aerosol cooling element.

[0140] The support element may be formed from any suitable material or combination of materials. For example, the support element may be formed from one or more materials selected from the group consisting of cellulose acetate, cardboard, crimped paper (such as crimped heat-resistant paper or crimped parchment paper), and polymeric materials (such as low-density polyethylene (LDPE)). In a preferred embodiment, the support element is formed from cellulose acetate. Other suitable materials include polyhydroxyalkanoate (PHA) fibers.

[0141] The support element may comprise a hollow tubular element. In a preferred embodiment, the support element comprises a hollow cellulose acetate tube.

[0142] The support element is disposed substantially in alignment with the rod-shaped aerosol-generating element, meaning that the length dimension of the support element is disposed approximately parallel to the longitudinal axis of the rod and article, e.g., within ±10 degrees of parallel to the longitudinal axis of the rod. In a preferred embodiment, the support element extends along the longitudinal axis of the rod.

[0143] The support element preferably has an outer diameter that is approximately equal to the outer diameter of the rod-shaped aerosol-generating element and the outer diameter of the aerosol-generating article.

[0144] The support element may have an outer diameter of 5 millimeters to 12 millimeters, such as an outer diameter of 5 millimeters to 10 millimeters, or an outer diameter of 6 millimeters to 8 millimeters. In a preferred embodiment, the support element has an outer diameter of 7.2 millimeters ± 10 percent.

[0145] The peripheral wall of the support element may have a thickness of at least 1 millimeter, preferably at least about 1.5 millimeters, and more preferably at least about 2 millimeters.

[0146] The support element may have a length of from about 5 millimeters to about 15 millimeters.

[0147] Preferably, the support element has a length of at least about 6 millimeters, and more preferably at least about 7 millimeters.

[0148] In preferred embodiments, the support element has a length of less than about 12 millimeters, more preferably less than about 10 millimeters.

[0149] In some embodiments, the support element has a length of about 5 millimeters to about 15 millimeters, preferably about 6 millimeters to about 15 millimeters, and more preferably about 7 millimeters to about 15 millimeters. In other embodiments, the support element has a length of about 5 millimeters to about 12 millimeters, preferably about 6 millimeters to about 12 millimeters, and more preferably about 7 millimeters to about 12 millimeters. In further embodiments, the support element has a length of about 5 millimeters to about 10 millimeters, preferably about 6 millimeters to about 10 millimeters, and more preferably about 7 millimeters to about 10 millimeters.

[0150] In a preferred embodiment, the support element has a length of about 8 millimeters.

[0151] The ratio of the length of the support element to the length of the hollow section may be from about 0.18 to about 1.00.

[0152] Preferably, the ratio of the length of the support element to the length of the hollow section is at least about 0.20, more preferably at least about 0.30, and even more preferably at least about 0.40. In preferred embodiments, the ratio of the length of the support element to the length of the hollow section is less than about 0.90, more preferably less than about 0.80, and even more preferably less than about 0.70.

[0153] In some embodiments, the ratio of the length of the support element to the length of the hollow section is about 0.20 to about 0.90, preferably about 0.30 to about 0.90, and more preferably about 0.40 to about 0.90. In other embodiments, the ratio of the length of the support element to the length of the hollow section is about 0.2 to about 0.8, preferably about 0.30 to about 0.80, and more preferably about 0.40 to about 0.80. In further embodiments, the ratio of the length of the support element to the length of the hollow section is about 0.20 to about 0.70, preferably about 0.30 to about 0.70, and more preferably about 0.40 to about 0.70.

[0154] In a particularly preferred embodiment, the ratio of the length of the support element to the length of the hollow section is about 0.50. In another particularly preferred embodiment, the ratio of the length of the support element to the length of the hollow section is about 0.29.

[0155] The ratio of the length of the support element to the length of the downstream section may be from about 0.18 to about 1.00.

[0156] Preferably, the ratio of the length of the support element to the length of the downstream section is at least about 0.20, more preferably at least about 0.23, and even more preferably at least about 0.25. In preferred embodiments, the ratio of the length of the support element to the length of the downstream section is less than about 0.90, more preferably less than about 0.60, and even more preferably less than about 0.40.

[0157] In some embodiments, the ratio of the length of the support element to the length of the downstream section is about 0.20 to about 1.00, preferably about 0.23 to about 1.00, and more preferably about 0.25 to about 1.00. In some embodiments, the ratio of the length of the support element to the length of the downstream section is about 0.20 to about 0.90, preferably about 0.23 to about 0.90, and more preferably about 0.25 to about 0.90. In other embodiments, the ratio of the length of the support element to the length of the downstream section is about 0.20 to about 0.60, preferably about 0.23 to about 0.60, and more preferably about 0.25 to about 0.60. In further embodiments, the ratio of the length of the support element to the length of the downstream section is about 0.20 to about 0.40, preferably about 0.23 to about 0.40, and more preferably about 0.25 to about 0.40.

[0158] In a particularly preferred embodiment, the ratio of the length of the support element to the length of the downstream section is about 0.29.

[0159] Preferably, the ratio of the length of the support element to the length of the rod-shaped aerosol-generating element is at least about 0.30, more preferably at least about 0.40, and even more preferably at least about 0.50. In preferred embodiments, the ratio of the length of the support element to the length of the rod of the aerosol-generating substrate is less than about 0.90, more preferably less than about 0.80, and even more preferably less than about 0.70.

[0160] In some embodiments, the ratio of the length of the support element to the length of the rod-shaped aerosol-generating element is about 0.30 to about 0.90, preferably about 0.40 to about 0.90, and more preferably about 0.50 to about 0.90. In other embodiments, the ratio of the length of the support element to the length of the rod of the aerosol-generating substrate is about 0.30 to about 0.80, preferably about 0.40 to about 0.80, and more preferably about 0.50 to about 0.80. In further embodiments, the ratio of the length of the support element to the length of the rod of the aerosol-generating substrate is about 0.30 to about 0.70, preferably about 0.40 to about 0.70, and more preferably about 0.50 to about 0.70.

[0161] In a particularly preferred embodiment, the ratio of the length of the support element to the length of the rod-shaped aerosol-generating element is about 0.67.

[0162] The ratio between the length of the support element and the overall length of the aerosol-generating article may be from about 0.125 to about 0.375.

[0163] Preferably, the ratio between the length of the support element and the overall length of the aerosol-generating article is at least about 0.13, more preferably at least about 0.14, and even more preferably at least about 0.15. The ratio between the length of the support element and the overall length of the aerosol-generating article is preferably less than about 0.30, more preferably less than about 0.25, and even more preferably less than about 0.20.

[0164] In some embodiments, the ratio between the length of the support element and the total length of the aerosol-generating article is preferably about 0.13 to about 0.30, more preferably about 0.14 to about 0.3, and even more preferably about 0.15 to about 0.30. In other embodiments, the ratio between the length of the support element and the total length of the aerosol-generating article is preferably about 0.13 to about 0.25, more preferably about 0.14 to about 0.25, and even more preferably about 0.15 to about 0.25. In further embodiments, the ratio between the length of the support element and the total length of the aerosol-generating article is preferably about 0.13 to about 0.20, more preferably about 0.14 to about 0.20, and even more preferably about 0.15 to about 0.20.

[0165] In a particularly preferred embodiment, the ratio between the length of the support element and the overall length of the aerosol-generating article is about 0.18.

[0166] Preferably, in aerosol-generating articles according to the present invention, the support element has an average radial hardness of at least about 80 percent, more preferably at least about 85 percent, and even more preferably at least about 90 percent, thus providing the aerosol-generating article with the desired level of hardness.

[0167] If desired, the radial stiffness of the support element of an aerosol-generating article according to the present invention may be further increased by surrounding the support element with a stiff plug wrap, such as a plug wrap having a basis weight of at least about 80 grams per square meter (gsm), or at least about 100 gsm, or at least about 110 gsm.

[0168] When inserting an aerosol-generating article according to the present invention into an aerosol-generating device to heat the aerosol-generating substrate, the user may need to apply some force to overcome the resistance to insertion of the aerosol-generating substrate of the aerosol-generating article. This may damage one or both of the aerosol-generating article and the aerosol-generating device. In addition, the application of force during insertion of the aerosol-generating article into the aerosol-generating device may displace the aerosol-generating substrate within the aerosol-generating article. This may result in the heating element of the aerosol-generating device not being properly aligned with the susceptor element provided within the aerosol-generating substrate, which may lead to uneven and inefficient heating of the aerosol-generating substrate of the aerosol-generating article. Advantageously, the support element is configured to resist downstream movement of the aerosol-generating substrate during insertion of the article into the aerosol-generating device.

[0169] Preferably, the hollow tubular element of the support element is adapted to generate an RTD of between approximately 0 millimeters of HO (about 0 Pa) and approximately 20 millimeters of HO (about 100 Pa), more preferably between approximately 0 millimeters of HO (about 0 Pa) and approximately 10 millimeters of HO (about 100 Pa). Thus, the support element preferably does not contribute to the overall RTD of the aerosol-generating article.

[0170] As described above, the hollow section may further include a second hollow tubular element or aerosol-cooling element located downstream of the aerosol-generation element. The second hollow tubular element or aerosol-cooling element may be located immediately downstream of the first hollow tubular element or support element and abut the first hollow tubular element. The first and second hollow tubular elements may define a longitudinal cavity that provides an unrestricted flow channel.

[0171] The aerosol cooling element is disposed substantially in alignment with the rod-shaped aerosol-generating element. This means that the length dimension of the aerosol-cooling element is disposed approximately parallel to the longitudinal axis of the rod-shaped aerosol-generating element and the article, for example, within ±10 degrees of parallel to the longitudinal axis of the rod-shaped element. In a preferred embodiment, the aerosol-cooling element extends along the longitudinal axis of the rod-shaped aerosol-generating element.

[0172] In an aerosol-generating article according to the invention, the aerosol cooling element is in the form of a hollow tubular element defining a cavity extending entirely from the upstream end of the aerosol cooling element to the downstream end of the aerosol cooling element, and ventilation zones are preferably provided at locations along the hollow tubular element.

[0173] The inventors have found that satisfactory cooling of the aerosol stream generated upon heating of an aerosol-generating substrate and drawn through one such aerosol-cooling element can be achieved by providing a ventilation zone at a location along the hollow tubular element. Furthermore, the inventors have found that by disposing a ventilation zone at a precisely defined location along the length of the aerosol-cooling element, and preferably by utilizing a hollow tubular element having a predetermined peripheral wall thickness or internal volume, as described in more detail below, it may be possible to counter the effects of increased aerosol dilution caused by ventilation air entering the article.

[0174] Without being bound by theory, it is believed that the introduction of ventilated air rapidly reduces the temperature of the aerosol stream as it moves toward the mouthpiece, so that the ventilated air enters the aerosol stream relatively close to the upstream end of the aerosol-cooling element (i.e., close enough to the susceptor element extending to the rod-shaped aerosol-generating element, which is the heat source in use), achieving dramatic cooling of the aerosol stream, which has a favorable effect on aerosol particle condensation and nucleation. As a result, the overall ratio of aerosol particle phase to aerosol vapor phase may be increased compared to existing non-vented aerosol-generating articles.

[0175] At the same time, maintaining a relatively low peripheral wall thickness of the hollow tubular element ensures that the overall internal volume of the hollow tubular element (which is available for the aerosol to initiate the nucleation process as soon as the aerosol components leave the rod-shaped aerosol-generating element) and the cross-sectional surface area of ​​the hollow tubular element are effectively maximized, while at the same time ensuring that the hollow tubular element has the structural strength necessary not only to prevent collapse of the aerosol-generating article but also to provide some support for the rod-shaped aerosol-generating element, and that the RTD of the hollow tubular element is minimized. It is understood that a larger value for the cross-sectional surface area of ​​the hollow tubular element's cavity is associated with a reduced velocity of the aerosol flow traveling along the aerosol-generating article, which is also expected to favor aerosol nucleation. Furthermore, by utilizing a hollow tubular element with a relatively small thickness, it may be thought possible to substantially prevent the diffusion of the ventilation air before it contacts and mixes with the aerosol flow, which is also understood to further favor the nucleation phenomenon. Indeed, by providing more controllably localized cooling of the stream of volatilized species, it is possible to enhance the effect of cooling on the formation of new aerosol particles.

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

[0177] The aerosol cooling element may have an outer diameter of 5 millimeters to 12 millimeters, such as an outer diameter of 5 millimeters to 10 millimeters, or an outer diameter of 6 millimeters to 8 millimeters. In a preferred embodiment, the aerosol cooling element has an outer diameter of 7.2 millimeters plus or minus 10 percent.

[0178] Preferably, the hollow tubular element of the aerosol cooling element has an inner diameter of at least about 2 millimeters. More preferably, the hollow tubular element of the aerosol cooling element has an inner diameter of at least about 2.5 millimeters. Even more preferably, the hollow tubular element of the aerosol cooling element has an inner diameter of at least about 3 millimeters.

[0179] The peripheral wall of the aerosol cooling element may have a thickness of less than about 2.5 millimeters, preferably less than about 1.5 millimeters, more preferably less than about 1250 micrometers, and even more preferably less than about 1000 micrometers. In particularly preferred embodiments, the peripheral wall of the aerosol cooling element has a thickness of less than about 900 micrometers, preferably less than about 800 micrometers.

[0180] In one embodiment, the peripheral wall of the aerosol cooling element has a thickness of about 2 millimeters.

[0181] The aerosol cooling element may have a length of between 5 millimeters and 15 millimeters.

[0182] Preferably, the aerosol cooling element has a length of at least about 6 millimeters, and more preferably at least about 7 millimeters.

[0183] In preferred embodiments, the aerosol cooling element has a length of less than about 12 millimeters, more preferably less than about 10 millimeters.

[0184] In some embodiments, the aerosol cooling element has a length of about 5 millimeters to about 15 millimeters, preferably about 6 millimeters to about 15 millimeters, and more preferably about 7 millimeters to about 15 millimeters. In other embodiments, the aerosol cooling element has a length of about 5 millimeters to about 12 millimeters, preferably about 6 millimeters to about 12 millimeters, and more preferably about 7 millimeters to about 12 millimeters. In further embodiments, the aerosol cooling element has a length of about 5 millimeters to about 10 millimeters, preferably about 6 millimeters to about 10 millimeters, and more preferably about 7 millimeters to about 10 millimeters.

[0185] In particularly preferred embodiments of the present invention, the aerosol cooling element has a length of less than 10 millimeters. For example, in one particularly preferred embodiment, the aerosol cooling element has a length of 8 millimeters. In such an embodiment, the aerosol cooling element therefore has a relatively short length compared to aerosol cooling elements of prior art aerosol-generating articles. The reduction in the length of the aerosol cooling element is possible due to optimizing the effectiveness of the hollow tubular element forming the aerosol cooling element in aerosol cooling and nucleation. The reduction in the length of the aerosol cooling element advantageously reduces the risk of deformation of the aerosol-generating article due to compression during use, because the aerosol cooling element typically has lower resistance to deformation than the mouthpiece. Furthermore, the reduction in the length of the aerosol cooling element can provide cost benefits to manufacturers, because the cost of the hollow tubular element is typically higher per unit length than the cost of other elements, such as the mouthpiece.

[0186] The ratio of the length of the aerosol cooling element to the length of the hollow section may be from about 0.18 to about 1.00.

[0187] Preferably, the ratio of the length of the aerosol cooling element to the length of the hollow section is at least about 0.20, more preferably at least about 0.30, and even more preferably at least about 0.40. In preferred embodiments, the ratio of the length of the aerosol cooling element to the length of the hollow section is less than about 0.90, more preferably less than about 0.80, and even more preferably less than about 0.70.

[0188] In some embodiments, the ratio of the length of the aerosol-cooling element to the length of the hollow section is about 0.20 to about 0.90, preferably about 0.30 to about 0.90, and more preferably about 0.40 to about 0.90. In other embodiments, the ratio of the length of the aerosol-cooling element to the length of the hollow section is about 0.20 to about 0.80, preferably about 0.30 to about 0.80, and more preferably about 0.40 to about 0.80. In further embodiments, the ratio of the length of the aerosol-cooling element to the length of the hollow section is about 0.20 to about 0.70, preferably about 0.30 to about 0.70, and more preferably about 0.40 to about 0.70.

[0189] In a particularly preferred embodiment, the ratio of the length of the aerosol cooling element to the length of the hollow section is about 0.29. In another preferred embodiment, the ratio of the length of the aerosol cooling element to the length of the hollow section is about 0.50.

[0190] The ratio of the length of the aerosol cooling element to the length of the downstream section is from about 0.18 to about 1.00.

[0191] Preferably, the ratio of the length of the aerosol-cooling element to the length of the downstream section is at least about 0.20, more preferably at least about 0.23, and even more preferably at least about 0.25. In preferred embodiments, the ratio of the length of the aerosol-cooling element to the length of the downstream section is less than about 0.90, more preferably less than about 0.60, and even more preferably less than about 0.50.

[0192] In some embodiments, the ratio of the length of the aerosol-cooling element to the length of the downstream section is about 0.20 to about 0.90, preferably about 0.23 to about 0.90, and more preferably about 0.25 to about 0.90. In other embodiments, the ratio of the length of the aerosol-cooling element to the length of the downstream section is about 0.20 to about 0.60, preferably about 0.23 to about 0.60, and more preferably about 0.25 to about 0.60. In further embodiments, the ratio of the length of the aerosol-cooling element to the length of the downstream section is about 0.20 to about 0.50, preferably about 0.23 to about 0.40, and more preferably about 0.25 to about 0.50.

[0193] In a particularly preferred embodiment, the ratio of the length of the aerosol cooling element to the length of the downstream section is about 0.29.

[0194] The ratio of the length of the aerosol-cooling element to the length of the rod-shaped aerosol-generating element may be from about 0.25 to about 1.00.

[0195] Preferably, the ratio of the length of the aerosol-cooling element to the length of the rod-shaped aerosol-generating element is at least about 0.30, more preferably at least about 0.40, and even more preferably at least about 0.50. In preferred embodiments, the ratio of the length of the aerosol-cooling element to the length of the rod-shaped aerosol-generating element is less than about 0.90, more preferably less than about 0.80, and even more preferably less than about 0.70.

[0196] In some embodiments, the ratio of the length of the aerosol-cooling element to the length of the rod-shaped aerosol-generating element is about 0.30 to about 0.90, preferably about 0.40 to about 0.90, and more preferably about 0.50 to about 0.90. In other embodiments, the ratio of the length of the aerosol-cooling element to the length of the rod-shaped aerosol-generating element is about 0.30 to about 0.80, preferably about 0.40 to about 0.80, and more preferably about 0.50 to about 0.80. In further embodiments, the ratio of the length of the aerosol-cooling element to the length of the rod-shaped aerosol-generating element is about 0.30 to about 0.70, preferably about 0.40 to about 0.70, and more preferably about 0.50 to about 0.70.

[0197] In a particularly preferred embodiment, the ratio of the length of the aerosol-cooling element to the length of the rod-shaped aerosol-generating element is about 0.67.

[0198] The ratio between the length of the aerosol-cooling element and the overall length of the aerosol-generating article substrate may be from about 0.125 to about 0.375.

[0199] Preferably, the ratio between the length of the aerosol cooling element and the overall length of the aerosol-generating article is at least about 0.13, more preferably at least about 0.14, and even more preferably at least about 0.15. Preferably, the ratio between the length of the aerosol cooling element and the overall length of the aerosol-generating article is less than about 0.30, more preferably less than about 0.25, and even more preferably less than about 0.20.

[0200] In some embodiments, the ratio between the length of the aerosol-cooling element and the total length of the aerosol-generating article is preferably about 0.13 to about 0.30, more preferably about 0.14 to about 0.30, and even more preferably about 0.15 to about 0.30. In other embodiments, the ratio between the length of the aerosol-cooling element and the total length of the aerosol-generating article is preferably about 0.13 to about 0.25, more preferably about 0.14 to about 0.25, and even more preferably about 0.15 to about 0.25. In further embodiments, the ratio between the length of the aerosol-cooling element and the total length of the aerosol-generating article is preferably about 0.13 to about 0.20, more preferably about 0.14 to about 0.20, and even more preferably about 0.15 to about 0.20.

[0201] In a particularly preferred embodiment, the ratio between the length of the aerosol-cooling element and the overall length of the aerosol-generating article is about 0.18.

[0202] The length of the mouthpiece section is preferably at least 1 millimeter greater than the length of the aerosol cooling element, more preferably at least 2 millimeters greater than the length of the aerosol cooling element, and more preferably at least 3 millimeters greater than the length of the aerosol cooling element. Reducing the length of the aerosol cooling element as described above can advantageously allow for an increase in the length of other elements of the aerosol-generating article, such as the mouthpiece section. Potential technical benefits of providing a relatively long mouthpiece section are described below.

[0203] In some preferred embodiments, the mouthpiece section comprises a single mouthpiece filter segment, the length of which is preferably at least 1 millimeter greater than the length of the aerosol cooling element, more preferably at least 2 millimeters greater than the length of the aerosol cooling element, and more preferably at least 3 millimeters greater than the length of the aerosol cooling element.

[0204] In some embodiments, the second aerosol cooling element may be located downstream of the aerosol cooling element. The second aerosol cooling element may be in the form of a third hollow tubular element. The second aerosol cooling element may abut the aerosol cooling element at the downstream end of the aerosol cooling element. The third hollow tubular element may abut the second hollow tubular element at the downstream end of the second hollow tubular element. In such embodiments, the hollow section includes first, second, and third hollow tubular elements, the first, second, and third hollow tubular elements defining a longitudinal cavity that provides an unrestricted flow channel. The second aerosol cooling element may extend all the way to the mouth end of the aerosol-generating article. The third hollow tubular element may extend to the mouth end of the aerosol-generating article. The support element, the aerosol cooling element, and the second aerosol cooling element may form a hollow section extending from the downstream end of the rod of the aerosol-generating substrate to the mouth end of the aerosol-generating article. The first hollow tubular element, the second hollow tubular element and the third hollow tubular element may form a hollow section extending from the downstream end of the rod of the aerosol-generating substrate to the mouth end of the aerosol-generating article.

[0205] The second aerosol cooling element preferably has a length of between 5 millimeters and 15 millimeters, and in a particularly preferred embodiment, the length of the second aerosol cooling element may be 12 millimeters.

[0206] The third hollow tubular element comprising the second aerosol cooling element preferably has an inner diameter of at least about 2 millimeters. More preferably, the hollow tubular element of the second aerosol cooling element has an inner diameter of at least about 2.5 millimeters. Even more preferably, the hollow tubular element of the second aerosol cooling element has an inner diameter of at least about 3 millimeters.

[0207] The peripheral wall of the second aerosol cooling element may have a thickness of less than about 2.5 millimeters, preferably less than about 1.5 millimeters, more preferably less than about 1250 micrometers, and even more preferably less than about 1000 micrometers. In particularly preferred embodiments, the peripheral wall of the second aerosol cooling element has a thickness of less than about 900 micrometers, preferably less than about 800 micrometers.

[0208] In one embodiment, the peripheral wall of the second aerosol cooling element has a thickness of about 2 millimeters.

[0209] In aerosol-generating articles according to the present invention, the aerosol cooling element preferably has an average radial hardness of at least about 80 percent, more preferably at least about 85 percent, and even more preferably at least about 90 percent, such that the aerosol cooling element can provide the aerosol-generating article with the desired level of hardness.

[0210] If desired, the radial stiffness of the aerosol cooling element of an aerosol-generating article according to the present invention may be further increased by surrounding the aerosol cooling element with a stiff plug wrap, such as a plug wrap having a basis weight of at least about 80 grams per square meter (gsm), or at least about 100 gsm, or at least about 110 gsm.

[0211] As used herein, the term "radial hardness" refers to resistance to compression in a direction transverse to the longitudinal axis of the element. The radial hardness of an aerosol-generating article around a given element can be determined by applying a load across the article at the location of the support element in a direction transverse to the longitudinal axis of the article and measuring the average (mean) depressed diameter of the article. Radial hardness is given by: [Formula 1] JPEG2026503531000002.jpg1561D S is the original (undepressed) diameter, and D dis the depressed diameter after applying a set load for a set duration. The harder the material, the closer the hardness will be to 100 percent.

[0212] To determine the hardness of a portion of an aerosol-generating article (such as a support element or an aerosol-cooling element provided in the form of a hollow tubular element), the aerosol-generating articles should be aligned parallel in a plane, and the same portion of each aerosol-generating article to be tested should be subjected to a set load for a set duration. This test is carried out using a known DD60A Densimeter instrument (manufactured and sold by Heinr Borgwaldt GmbH, Germany), which is fitted with a measuring head for aerosol-generating articles such as cigarettes, and which also includes an aerosol-generating article container.

[0213] Load is applied using two load-applying cylindrical rods that extend across the diameter of all aerosol-generating articles at once. According to the standard test method for this instrument, the test should be conducted so that 20 contact points are created between the aerosol-generating articles and the load-applying cylindrical rods. In some cases, the hollow tubular element being tested may be long enough so that only 10 aerosol-generating articles are needed to form 20 contact points where each smoking article contacts both load-applying rods (because they are long enough to extend between both rods). In other cases, if the support element is too short to achieve this, 20 aerosol-generating articles should be used to form 20 contact points, with each aerosol-generating article contacting only one of the load-applying rods, as discussed further below.

[0214] Two additional fixed cylindrical rods are positioned below the aerosol-generating article to support the aerosol-generating article and counter the loads exerted by each of the load-applying cylindrical rods.

[0215] For standard operating procedures for such devices, a total load of 2 kg is applied for 20 seconds. After 20 seconds have elapsed (and the load is still applied to the smoking article), the depression on the load-applying cylindrical rod is determined and then used to calculate hardness from the above equation. The temperature is maintained within a range of 22 degrees Celsius ± 2 degrees Celsius. The above test is referred to as the DD60A test. The standard method for measuring filter hardness is when the aerosol-generating article has not yet been consumed. Additional information regarding measuring average radial hardness can be found, for example, in U.S. Published Patent Application Publication No. 2016 / 0128378.

[0216] The aerosol cooling element may be formed from any suitable material or combination of materials. For example, the aerosol cooling element may be formed from one or more materials selected from the group consisting of cellulose acetate, cardboard, crimped paper (such as crimped heat-resistant paper or crimped parchment paper), and polymeric materials (such as low-density polyethylene (LDPE)). Other suitable materials include polyhydroxyalkanoate (PHA) fibers.

[0217] In a preferred embodiment, the aerosol cooling element is formed from cellulose acetate.

[0218] Preferably, the hollow tubular element of the aerosol cooling element is adapted to generate an RTD of approximately 0 millimeters HO (about 0 Pa) to approximately 20 millimeters HO (about 100 Pa), more preferably approximately 0 millimeters HO (about 0 Pa) to approximately 10 millimeters HO (about 100 Pa).

[0219] In an aerosol-generating article according to the invention, the overall RTD of the article depends essentially on the RTD of the rod and, optionally, the RTD of the mouthpiece and / or upstream plug, since the hollow tubular elements of the aerosol-cooling element and the hollow tubular elements of the support element are substantially empty and therefore only make a substantially small contribution to the overall RTD of the aerosol-generating article.

[0220] In some embodiments where the hollow section includes both a support element comprising a first hollow tubular element and an aerosol cooling element comprising a second hollow tubular element, the inner diameter (D STS ) is the inner diameter (D FTS ) is preferably greater than

[0221] More specifically, the inner diameter (D STS ) and the inner diameter (D FTS ) is preferably at least about 1.25. More preferably, the ratio of the inner diameter (D STS ) and the inner diameter (D FTS ) is preferably at least about 1.30. Even more preferably, the ratio of the inner diameter (D STS ) and the inner diameter (D FTS ) is preferably at least about 1.40. In a particularly preferred embodiment, the ratio of the inner diameter (D STS ) and the inner diameter (D FTS ) is at least about 1.50, more preferably at least about 1.60.

[0222] The inner diameter (D STS ) and the inner diameter (D FTS ) is preferably about 2.50 or less. More preferably, the ratio of the inner diameter (D STS ) and the inner diameter (D FTS ) is preferably about 2.25 or less. Even more preferably, the ratio of the inner diameter (D STS ) and the inner diameter (D FTS ) is preferably about 2.00 or less.

[0223] In some embodiments, the inner diameter (D STS ) and the inner diameter (D FTS) is about 1.25 to about 2.50. STS ) and the inner diameter (D FTS ) is about 1.30 to about 2.50. STS ) and the inner diameter (D FTS In a particularly preferred embodiment, the ratio of the inner diameter (D STS ) and the inner diameter (D FTS ) is about 1.50 to about 2.50.

[0224] In other embodiments, the inner diameter (D STS ) and the inner diameter (D FTS ) is about 1.25 to about 2.25. Preferably, the ratio of the inner diameter (D STS ) and the inner diameter (D FTS ) is about 1.30 to about 2.25. STS ) and the inner diameter (D FTS In a particularly preferred embodiment, the ratio of the inner diameter (D STS ) and the inner diameter (D FTS ) is about 1.50 to about 2.25.

[0225] In a further embodiment, the inner diameter (D STS ) and the inner diameter (D FTS ) is about 1.25 to about 2.00. Preferably, the ratio of the inner diameter (D STS ) and the inner diameter (D FTS ) is about 1.30 to about 2.00. STS ) and the inner diameter (D FTSIn a particularly preferred embodiment, the ratio of the inner diameter (D STS ) and the inner diameter (D FTS ) is about 1.50 to about 2.00.

[0226] In those embodiments in which the article further comprises an elongated susceptor element longitudinally disposed within the aerosol-generating substrate, the inner diameter (D FTS Preferably, the ratio of the inner diameter (D ) of the first hollow tubular element to the width of the susceptor element is at least about 0.20. More preferably, FTS ) to the width of the susceptor element is at least about 0.30. Even more preferably, the ratio of the inner diameter (D FTS The ratio of the length of the susceptor element to the width of the susceptor element is at least about 0.40.

[0227] Additionally or alternatively, the inner diameter (D STS Preferably, the ratio of the inner diameter (D ) of the second hollow tubular element to the width of the susceptor element is at least about 0.20. More preferably, STS ) to the width of the susceptor element is at least about 0.50. Even more preferably, the ratio of the inner diameter (D STS The ratio of the length of the susceptor element to the width of the susceptor element is at least about 0.80.

[0228] Preferably, the ratio of the cavity volume of the first hollow tubular element to the cavity volume of the second hollow tubular element is at least about 0.10. More preferably, the ratio of the cavity volume of the first hollow tubular element to the cavity volume of the second hollow tubular element is at least about 0.20. Even more preferably, the ratio of the cavity volume of the first hollow tubular element to the cavity volume of the second hollow tubular element is at least about 0.30.

[0229] Preferably, the ratio of the cavity volume of the first hollow tubular element to the cavity volume of the second hollow tubular element is about 0.90 or less. More preferably, the ratio of the cavity volume of the first hollow tubular element to the cavity volume of the second hollow tubular element is about 0.70 or less. Even more preferably, the ratio of the cavity volume of the first hollow tubular element to the cavity volume of the second hollow tubular element is about 0.50 or less.

[0230] In an aerosol-generating article according to the present invention, the downstream section may include a vent that allows cooler air from outside the aerosol-generating article to enter the interior of the downstream section.

[0231] The term "ventilation level" is used throughout this specification to mean the volume ratio of the airflow entering the aerosol-generating article through the ventilation zone (ventilation airflow) to the sum of the aerosol airflow and the ventilation airflow. The greater the ventilation level, the greater the dilution of the aerosol stream delivered to the consumer.

[0232] Aerosol-generating articles may typically have a breathability level of at least about 10 percent, preferably at least about 20 percent.

[0233] In preferred embodiments, the aerosol-generating article has a breathability level of at least about 20 percent, 25 percent, or 30 percent. More preferably, the aerosol-generating article has a breathability level of at least about 35 percent.

[0234] Preferably, the aerosol-generating article has a breathability level of less than about 80 percent. More preferably, the aerosol-generating article has a breathability level of less than about 60 percent or less than about 50 percent.

[0235] Aerosol-generating articles generally have a breathability level of about 10 percent to about 80 percent.

[0236] In some embodiments, the aerosol-generating article has a ventilation level of about 20 percent to about 80 percent, with about 20 percent to about 60 percent being preferred, and about 20 percent to about 50 percent being more preferred. In other embodiments, the aerosol-generating article has a ventilation level of about 25 percent to about 80 percent, with about 25 percent to about 60 percent being preferred, and about 25 percent to about 50 percent being more preferred. In other embodiments, the aerosol-generating article has a ventilation level of about 30 percent to about 80 percent, with about 30 percent to about 60 percent being preferred, and about 30 percent to about 50 percent being more preferred.

[0237] In some particularly preferred embodiments, the aerosol-generating article has a breathability level of about 30 percent. In some particularly preferred embodiments, the aerosol-generating article has a breathability level of about 45 percent.

[0238] Without wishing to be bound by theory, the inventors have found that the temperature reduction caused by admitting cooler outside air into the hollow tubular element through the ventilation zone can have a beneficial effect on the nucleation and growth of aerosol particles.

[0239] The formation of aerosols from gaseous mixtures containing various chemical species depends on a delicate interplay between nucleation, evaporation, condensation, and even fusion, which accounts for changes in vapor concentration, temperature, and velocity fields. The so-called classical nucleation theory is based on the assumption that a fraction of molecules in the gas phase are large enough to remain coherent for a long time with a sufficient probability (e.g., a 50 / 50 chance). These molecules represent a certain kind of critical, threshold molecular cluster within the transient molecular aggregates, meaning that smaller molecular clusters generally tend to break down into the gas phase rather quickly, while larger clusters generally tend to grow. These critical clusters are identified as primary nucleation cores from which droplets are expected to grow due to the condensation of molecules from the vapor. It is assumed that freshly nucleated, virgin droplets emerge with a certain original diameter and may subsequently grow by several orders of magnitude. This may be facilitated and enhanced by the rapid cooling of the surrounding vapor, which induces condensation. In this regard, it is helpful to remember that evaporation and condensation are two aspects of one and the same mechanism: gas-liquid mass transfer. Evaporation involves the net mass transfer from the droplets to the gas phase, while condensation is the net mass transfer from the gas phase to the droplet phase. Evaporation (or condensation) causes the droplets to shrink (or grow), but the number of droplets remains the same.

[0240] In this scenario (when the scenario is further complicated by fusion phenomena), the temperature and rate of cooling may play an important role in determining how the system responds. In general, because the nucleation process is typically nonlinear, different cooling rates may lead to significantly different temperature behaviors with respect to the formation of the liquid phase (droplets). Without wishing to be bound by theory, it is hypothesized that cooling can cause a rapid increase in the number of condensed droplets, followed by a short-term, strong increase in this growth (nucleation burst). This nucleation burst appears to be more pronounced at lower temperatures. Furthermore, it appears that a faster cooling rate may favor the onset of early nucleation. In contrast, a reduction in the cooling rate appears to have a favorable effect on the final size that the aerosol droplets ultimately reach.

[0241] Thus, the rapid cooling induced by admitting ambient air into the hollow tubular element via the ventilation zone can be used to favor favorable nucleation and growth of aerosol droplets. At the same time, however, admitting ambient air into the hollow tubular element has the direct drawback of diluting the aerosol stream delivered to the consumer.

[0242] The inventors have surprisingly discovered how the favorable effects of enhanced nucleation promoted by the rapid cooling induced by the introduction of ventilation air into the article can significantly counteract the less desirable effects of dilution, and thus satisfactory values ​​of aerosol delivery are consistently achieved by aerosol-generating articles in accordance with the present invention.

[0243] The inventors have also surprisingly found that the dilution effect on the aerosol—which can be assessed particularly by measuring the effect on the delivery of an aerosol former (such as glycerol) contained in the aerosol-generating substrate—is advantageously minimized when the aeration level is within the above-mentioned range. In particular, aeration levels of 30 percent to 50 percent have been found to lead to particularly satisfactory glycerin delivery values. At the same time, the degree of nucleation, and consequently, the delivery of nicotine and aerosol former (e.g., glycerol), is enhanced.

[0244] This is particularly advantageous for "short" aerosol-generating articles, such as a rod of aerosol-generating substrate less than about 40 millimeters in length, preferably less than 25 millimeters, and even more preferably less than 20 millimeters, or a total length of the aerosol-generating article less than about 70 millimeters, preferably less than about 60 millimeters, and even more preferably less than 50 millimeters. As will be appreciated, with such aerosol-generating articles, there is less time and space for aerosol formation and for the particle phase of the aerosol to become available for delivery to the consumer.

[0245] Furthermore, because the vented hollow tubular element does not substantially contribute to the overall RTD of the aerosol-generating article, the overall RTD of the article can be advantageously fine-tuned in an aerosol-generating article according to the present invention by adjusting the length and density of the rod of the aerosol-generating substrate, or the length and density of the segment of filtering material that optionally forms part of the mouthpiece, or the length and density of the segment of filtering material provided upstream of the aerosol-generating substrate and susceptor element. Therefore, aerosol-generating articles having a predetermined RTD can be consistently and precisely manufactured, thereby providing a satisfactory level of RTD for the consumer, even in the presence of ventilation.

[0246] The ventilation into the downstream section can occur along substantially the entire length of the downstream section. In this case, the downstream section may include a porous material that allows air to enter the downstream section. For example, if the downstream section includes a hollow tubular element, the hollow element may be formed from a porous material that allows air to enter the interior of the hollow tubular element. If the downstream section includes a wrapper, the wrapper may be formed from a porous material that allows air to enter the interior of the hollow tubular element.

[0247] The downstream section may include a first ventilation zone for providing ventilation to the downstream section. The ventilation zone includes a portion of the downstream section through which a greater amount of air can pass compared to the remainder of the downstream section. For example, the ventilation zone may be a portion of the downstream section having a higher void volume than the remainder of the downstream section.

[0248] The ventilation zone may include a plurality of perforations through the peripheral wall of the hollow tubular element. In some embodiments, the ventilation zone includes a plurality of perforations through the peripheral wall of the aerosol-cooling element. Preferably, the ventilation zone 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 between 8 and 30 perforations.

[0249] Where the aerosol-generating article comprises a combined plug wrap, the ventilation zone preferably comprises at least one corresponding circumferential row of perforations extending through a portion of the combined plug wrap, which may be formed online during manufacture of the smoking article. Preferably, the one or more circumferential rows of perforations extending through the portion of the combined plug wrap are substantially aligned with the one or more rows of perforations extending through the downstream section.

[0250] Where the aerosol-generating article comprises a strip of tipping paper that extends across one or more circumferential rows of perforations in the downstream section, the ventilation zone preferably comprises at least one corresponding circumferential row of perforations through the strip of tipping paper, which may be formed online during manufacture of the smoking article. Preferably, the one or more circumferential rows of perforations through the strip of tipping paper are substantially aligned with the one or more rows of perforations through the downstream section.

[0251] The first perforation line can include at least one perforation having a width of at least about 50 micrometers. For example, the first perforation line can include at least one perforation having a width of at least about 65 micrometers, at least about 80 micrometers, at least about 90 micrometers, or at least about 100 micrometers.

[0252] The first perforation line can include at least one perforation having a width of about 200 micrometers or less. For example, the first perforation line can include at least one perforation having a width of about 175 micrometers or less, about 150 micrometers or less, about 125 micrometers or less, or about 120 micrometers or less.

[0253] The first perforation line can comprise at least one perforation having a width of about 50 micrometers to about 200 micrometers, about 65 micrometers to about 175 micrometers, about 90 micrometers to about 150 micrometers, or about 100 micrometers to about 120 micrometers.

[0254] When the perforations are formed using laser drilling techniques, the width of the perforations can be determined by the focal diameter of the laser.

[0255] The first perforation line can include at least one perforation having a length of at least about 400 micrometers. For example, the first perforation line can include at least one perforation having a length of at least about 425 micrometers, at least about 450 micrometers, at least about 475 micrometers, or at least about 500 micrometers.

[0256] The first perforation line can include at least one perforation having a length of about 1 millimeter or less. For example, the first perforation line can include at least one perforation having a length of about 950 micrometers or less, about 900 micrometers or less, about 850 micrometers or less, or about 800 micrometers or less.

[0257] The first perforation line can comprise at least one perforation having a length of about 400 micrometers to about 1 millimeter, about 425 micrometers to about 950 micrometers, about 450 micrometers to about 900 micrometers, about 475 micrometers to about 850 micrometers, or about 500 micrometers to about 800 micrometers.

[0258] The first perforated line can include at least one perforation having an open area of ​​at least about 0.01 square millimeters. For example, the first perforated line can include at least one perforation having an open area of ​​at least about 0.02 square millimeters, at least about 0.03 square millimeters, or at least about 0.05 square millimeters.

[0259] The first perforated line can include at least one perforation having an open area of ​​about 0.5 square millimeters or less. For example, the first perforated line can include at least one perforation having an open area of ​​about 0.3 square millimeters or less, about 0.25 square millimeters or less, or about 0.1 square millimeters or less.

[0260] The first perforated line can include at least one perforation having an open area of ​​about 0.01 square millimeters to about 0.5 square millimeters, about 0.02 square millimeters to about 0.3 square millimeters, about 0.03 square millimeters to about 0.25 square millimeters, or about 0.05 square millimeters to about 0.1 square millimeters. The first perforated line can include at least one perforation having an open area of ​​about 0.05 square millimeters to about 0.096 square millimeters.

[0261] As noted above, the aerosol-generating article may include a wrapper surrounding at least a portion of the downstream section, and the ventilation zone may comprise a porous portion of the wrapper.

[0262] The wrapper may be a paper wrapper and the ventilation zone may comprise a portion of the porous paper.

[0263] The porous portion of the wrapper that forms the first ventilation zone may have a basis weight that is lower than the basis weight of the portion of the wrapper that does not form part of the ventilation zone.

[0264] The porous portion of the wrapper that forms the ventilation zone may have a thickness that is less than the thickness of the portion of the wrapper that does not form part of the ventilation zone.

[0265] The upstream edge of the ventilation zone may be less than 10 millimeters from the downstream edge of the aerosol-generating substrate.

[0266] For example, the upstream edge of the ventilation zone may be less than 8 millimeters, less than 5 millimeters, less than 3 millimeters, or less than 1 millimeter from the downstream edge of the aerosol-generating substrate.

[0267] The upstream end of the ventilation zone may be longitudinally aligned with the downstream end of the aerosol-generating substrate.

[0268] The downstream edge of the ventilation zone may be 10 millimetres or less from the downstream edge of the aerosol-generating substrate, in other words, the ventilation zone may be located entirely within 10 millimetres of the aerosol-generating substrate.

[0269] For example, the downstream edge of the ventilation zone may be no more than 8 millimeters, no more than 5 millimeters, or no more than 3 millimeters from the downstream edge of the aerosol-generating substrate.

[0270] The ventilation zone may be located anywhere along the length of the downstream section. The downstream end of the ventilation zone may be located about 25 millimeters or less from the downstream end of the aerosol-generating article. For example, the ventilation zone may be located about 20 millimeters or less from the downstream end of the aerosol-generating article.

[0271] Positioning the ventilation zone as outlined above may advantageously prevent the ventilation zone from becoming blocked when the aerosol-generating article is inserted into the aerosol-generating device.

[0272] The downstream end of the ventilation zone may be located at least about 8 millimeters from the downstream end of the aerosol-generating article. For example, the downstream end of the ventilation zone may be located at least about 10 millimeters, at least 12 millimeters, or at least about 15 millimeters from the downstream end of the aerosol-generating article.

[0273] Positioning the ventilation zone as outlined above may advantageously prevent the ventilation zone from being blocked by the user's mouth or lips during use of the aerosol-generating article.

[0274] The downstream end of the ventilation zone may be located about 8 millimeters to about 25 millimeters, about 10 millimeters to about 25 millimeters, or about 15 millimeters to about 20 millimeters from the downstream end of the aerosol-generating article. The downstream end of the ventilation zone may be located about 18 millimeters from the downstream end of the aerosol-generating article.

[0275] The upstream edge of the ventilation zone may be located at least about 20 millimeters from the upstream edge of the aerosol-generating article. For example, the upstream edge of the ventilation zone may be located at least about 25 millimeters from the upstream edge of the aerosol-generating article.

[0276] Positioning the ventilation zone as outlined above may advantageously prevent the ventilation zone from becoming blocked when the aerosol-generating article is inserted into the aerosol-generating device.

[0277] The upstream edge of the ventilation zone may be located no more than 37 millimeters from the upstream edge of the aerosol-generating article. For example, the upstream edge of the ventilation zone may be located no more than about 30 millimeters from the upstream edge of the aerosol-generating article.

[0278] Positioning the ventilation zone as outlined above may advantageously prevent the ventilation zone from being blocked by the user's mouth or lips during use of the aerosol-generating article.

[0279] The upstream end of the ventilation zone may be located about 20 millimeters to about 37 millimeters, or about 25 millimeters to about 30 millimeters from the upstream end of the aerosol-generating article. The upstream end of the ventilation zone may be located at least about 27 millimeters from the upstream end of the aerosol-generating article.

[0280] The ventilation zone may have any length. The ventilation zone may have a length of at least 0.5 millimeters. In other words, the longitudinal distance between the downstream end of the ventilation zone and the upstream end of the ventilation zone is at least 0.5 millimeters. For example, the ventilation zone may have a length of at least 1 millimeter, at least 2 millimeters, at least 5 millimeters, or at least 8 millimeters.

[0281] The ventilation zone may have a length of 10 millimeters or less. For example, the ventilation zone may have a length of 8 millimeters or less, or 5 millimeters or less.

[0282] The ventilation zone may have a length of about 0.5 millimeters to about 10 millimeters. For example, the ventilation zone may have a length of about 1 millimeter to about 8 millimeters, or about 2 millimeters to about 5 millimeters.

[0283] As defined above, the downstream section of an aerosol-generating article according to one embodiment of the present invention includes a mouthpiece section. The mouthpiece section is preferably located at the downstream or mouth end of the aerosol-generating article. The mouthpiece section includes at least one mouthpiece filter segment formed from a fibrous filtration material for filtering the aerosol generated from the aerosol-generating substrate. Suitable fibrous filtration materials will be known to those skilled in the art. Particularly preferably, the at least one mouthpiece filter segment includes a cellulose acetate filter segment formed from cellulose acetate tow.

[0284] In certain preferred embodiments, the mouthpiece section consists of a single mouthpiece filter segment. The single mouthpiece filter segment may extend all the way to the oral end of the aerosol-generating article. In alternative embodiments, the mouthpiece section includes two or more mouthpiece filter segments axially aligned in end-to-end relationship with one another.

[0285] The upstream end of the mouthpiece section is defined by the upstream end of the most upstream mouthpiece filter segment. If a single mouthpiece filter segment is present, the upstream end of the mouthpiece section is defined by the upstream end of the mouthpiece filter segment. The downstream end of the mouthpiece section is defined by the downstream or mouth end of the aerosol-generating article.

[0286] In certain embodiments of the present invention, the mouthpiece section may include a mouth-end cavity at a downstream end of the mouthpiece section downstream of the mouthpiece filter segment as described above. The mouth-end cavity may be defined by a hollow tubular element provided at the downstream end of the mouthpiece filter segment. Alternatively, the mouth-end cavity may be defined by an outer wrapper of the mouthpiece section, the outer wrapper extending downstream from the mouthpiece filter segment.

[0287] The mouthpiece filter segment may optionally include a flavorant, which may be provided in any suitable form, for example, the mouthpiece filter segment may include one or more capsules, beads, or granules of flavorant, or one or more flavor-loaded threads or filaments.

[0288] According to this embodiment of the invention, the downstream section of the aerosol-generating article may include a first hollow tubular element or support element located immediately downstream of the rod of the aerosol-generating substrate. The mouthpiece section is preferably located downstream of the support element. The downstream section further includes a second hollow tubular element or aerosol cooling element located immediately downstream of the support element. The mouthpiece section is preferably located downstream of both the support element and the aerosol cooling element. Particularly preferably, the mouthpiece section is located immediately downstream of the aerosol cooling element. By way of example, a mouthpiece filter segment may abut the downstream end of the aerosol cooling element. The mouthpiece section preferably comprises a single mouthpiece filter segment extending all the way to the mouth end of the aerosol-generating article.

[0289] The mouthpiece filter segment preferably has a low particle filtration efficiency.

[0290] The mouthpiece section is preferably surrounded by plug wrap. Preferably, the mouthpiece section is non-ventilated so that air does not enter the aerosol-generating article along the mouthpiece section.

[0291] The mouthpiece section is preferably connected to one or more of the adjacent upstream components of the aerosol-generating article by a tipping wrapper.

[0292] Preferably, the mouthpiece section has an RTD of less than about 25 millimeters HO. More preferably, the mouthpiece section has an RTD of less than about 20 millimeters HO. More preferably, the mouthpiece section has an RTD of less than about 15 millimeters HO.

[0293] RTD values ​​of about 10 millimeters HO to about 25 millimeters HO, or about 10 millimeters HO to about 15 millimeters HO, are particularly preferred, as a mouthpiece section having one such RTD is expected to contribute minimally to the overall RTD of the aerosol-generating article, thereby providing substantially no filtering effect on the aerosol delivered to the consumer.

[0294] The one or more hollow tubular elements in the downstream section provide negligible RTD, such that in this embodiment the mouthpiece section provides a significant contribution to the RTD of the downstream section. Preferably, the downstream section has an RTD of less than about 25 millimeters of H2O. More preferably, the downstream section has an RTD of less than about 20 millimeters of H2O. More preferably, the downstream section has an RTD of less than about 15 millimeters of H2O. RTD values ​​of between about 10 millimeters of H2O and about 25 millimeters of H2O, or between about 10 millimeters of H2O and about 15 millimeters of H2O, are particularly preferred.

[0295] The mouthpiece section preferably has an outer diameter approximately equal to the outer diameter of the aerosol-generating article. The mouthpiece section may have an outer diameter of about 5 millimeters to about 10 millimeters, or about 6 millimeters to about 8 millimeters. In a preferred embodiment, the mouthpiece section has an outer diameter of about 7.2 millimeters.

[0296] The mouthpiece section preferably has a length of at least about 5 millimeters, more preferably at least about 8 millimeters, more preferably at least about 10 millimeters. Alternatively, or additionally, the mouthpiece section preferably has a length of less than about 25 millimeters, more preferably less than about 20 millimeters, more preferably less than about 15 millimeters.

[0297] In some embodiments, the mouthpiece section preferably has a length of about 5 millimeters to about 25 millimeters, more preferably about 8 millimeters to about 25 millimeters, and even more preferably about 10 millimeters to about 25 millimeters. In other embodiments, the mouthpiece section preferably has a length of about 5 millimeters to about 10 millimeters, more preferably about 8 millimeters to about 20 millimeters, and even more preferably about 10 millimeters to about 20 millimeters. In further embodiments, the mouthpiece section preferably has a length of about 5 millimeters to about 15 millimeters, more preferably about 8 millimeters to about 15 millimeters, and even more preferably about 10 millimeters to about 15 millimeters.

[0298] For example, the mouthpiece section may have a length of about 5 millimeters to about 25 millimeters, or about 8 millimeters to about 20 millimeters, or about 10 millimeters to about 15 millimeters. In a preferred embodiment, the mouthpiece section has a length of approximately 12 millimeters.

[0299] In certain preferred embodiments of the present invention, the mouthpiece section has a length of at least 10 millimeters. Thus, in such embodiments, the mouthpiece section is relatively long compared to the mouthpiece sections provided in prior art articles. Providing a relatively long mouthpiece section in the aerosol-generating article of the present invention can provide several benefits to consumers. The mouthpiece section is typically more resilient to deformation or better adapted to recover its original shape after deformation than other elements that may be provided downstream of the rod of the aerosol-generating substrate, such as an aerosol cooling element or a support element. Therefore, increasing the length of the mouthpiece section has been found to provide an improved grip by the consumer and facilitate insertion of the aerosol-generating article into a heating device. Longer mouthpieces can be additionally used to provide higher levels of filtration and removal of undesirable aerosol components, such as phenol, thereby delivering a higher quality aerosol. Furthermore, the use of longer mouthpiece sections allows for more complex mouthpieces to be provided, as there is more space for incorporating mouthpiece components such as capsules, threads, and restrictors.

[0300] In particularly preferred embodiments of the present invention, a mouthpiece section having a length of at least 10 millimeters is combined with a relatively short aerosol cooling element, for example, an aerosol cooling element having a length of less than 10 millimeters. This combination has been found to reduce the risk of deformation of the aerosol cooling element during use and provide a more rigid mouthpiece that contributes to a more efficient puffing action by the consumer.

[0301] The length of the mouthpiece section may be at least 0.40 times the overall length of the intermediate hollow section, preferably at least 0.50 times the length of the intermediate hollow section, more preferably at least 0.60 times the length of the intermediate hollow section, and more preferably at least 0.75 times the length of the intermediate hollow section. Thus, the ratio of the length of the mouthpiece section to the overall length of the intermediate hollow section is at least about 0.40, preferably at least about 0.50, more preferably at least about 0.60, and most preferably at least about 0.75.

[0302] The ratio of the length of the mouthpiece section to the length of the rod of the aerosol-generating substrate may be from about 0.50 to about 1.50.

[0303] The ratio of the length of the mouthpiece section to the length of the rod of the aerosol-generating substrate is preferably at least about 0.60, more preferably at least about 0.70, and even more preferably at least about 0.80. In preferred embodiments, the ratio of the length of the mouthpiece section to the length of the rod of the aerosol-generating substrate is less than about 1.40, more preferably less than about 1.30, and even more preferably less than about 1.20.

[0304] In some embodiments, the ratio of the length of the mouthpiece section to the length of the rod of the aerosol-generating substrate is about 0.60 to about 1.40, preferably about 0.70 to about 1.40, and more preferably about 0.80 to about 1.40. In other embodiments, the ratio of the length of the mouthpiece section to the length of the rod of the aerosol-generating substrate is about 0.60 to about 1.30, preferably about 0.70 to about 1.30, and more preferably about 0.80 to about 1.30. In a further embodiment, the ratio of the length of the mouthpiece section to the length of the rod of the aerosol-generating substrate is about 0.60 to about 1.20, preferably about 0.70 to about 1.20, and more preferably about 0.80 to about 1.20.

[0305] In a particularly preferred embodiment, the ratio of the length of the mouthpiece section to the length of the rod of the aerosol-generating substrate is about 1.00.

[0306] The ratio of the length of the mouthpiece section to the overall length of the aerosol-generating article substrate may be from about 0.20 to about 0.35.

[0307] Preferably, the ratio of the length of the mouthpiece section to the overall length of the aerosol-generating article is at least about 0.22, more preferably at least about 0.24, and even more preferably at least about 0.26. Preferably, the ratio of the length of the mouthpiece section to the overall length of the aerosol-generating article is less than about 0.34, more preferably less than about 0.32, and even more preferably less than about 0.30.

[0308] In some embodiments, the ratio of the length of the mouthpiece section to the overall length of the aerosol-generating article is preferably about 0.22 to about 0.34, more preferably about 0.24 to about 0.34, and even more preferably about 0.26 to about 0.34. In other embodiments, the ratio of the length of the mouthpiece section to the overall length of the aerosol-generating article is preferably about 0.22 to about 0.32, more preferably about 0.24 to about 0.32, and even more preferably about 0.26 to about 0.32. In further embodiments, the ratio of the length of the mouthpiece section to the overall length of the aerosol-generating article is preferably about 0.22 to about 0.30, more preferably about 0.24 to about 0.30, and even more preferably about 0.26 to about 0.30.

[0309] In a particularly preferred embodiment, the ratio of the length of the mouthpiece section to the overall length of the aerosol-generating article is about 0.27.

[0310] In some embodiments, the mouthpiece section comprises a single mouthpiece filter segment that extends all the way to the oral end of the aerosol-generating article, hi some embodiments, the mouthpiece section comprises a single mouthpiece filter segment and an oral end cavity at the downstream end of the mouthpiece section.

[0311] In embodiments containing a single mouthpiece filter segment, it is preferred that the mouthpiece filter segment have an RTD of less than about 25 millimeters HO. More preferably, the mouthpiece filter segment has an RTD of less than about 20 millimeters HO. More preferably, the mouthpiece filter segment has an RTD of less than about 15 millimeters HO.

[0312] RTD values ​​of about 10 millimeters HO to about 25 millimeters HO, or about 10 millimeters HO to about 15 millimeters HO, are particularly preferred, as a mouthpiece filter segment having one such RTD is expected to contribute minimally to the overall RTD of the aerosol-generating article, thereby providing substantially no filtration of the aerosol delivered to the consumer.

[0313] The one or more hollow tubular elements in the downstream section provide negligible RTD, such that the mouthpiece filter segment provides a significant contribution to the RTD of the downstream section in these embodiments. Preferably, the downstream section has an RTD of less than about 25 millimeters of H2O. More preferably, the downstream section has an RTD of less than about 20 millimeters of H2O. More preferably, the downstream section has an RTD of less than about 15 millimeters of H2O. RTD values ​​of between about 10 millimeters of H2O and about 25 millimeters of H2O, or between about 10 millimeters of H2O and about 15 millimeters of H2O, are particularly preferred.

[0314] The mouthpiece filter segment preferably has an outer diameter approximately equal to the outer diameter of the aerosol-generating article. The mouthpiece filter segment may have an outer diameter of about 5 millimeters to about 10 millimeters, or about 6 millimeters to about 8 millimeters. In a preferred embodiment, the mouthpiece section has an outer diameter of about 7.2 millimeters.

[0315] The mouthpiece filter segment preferably has a length of at least about 5 millimeters, more preferably at least about 8 millimeters, more preferably at least about 10 millimeters. Alternatively, or additionally, the mouthpiece filter segment preferably has a length of less than about 25 millimeters, more preferably less than about 20 millimeters, more preferably less than about 15 millimeters.

[0316] In some embodiments, the mouthpiece filter segment preferably has a length of about 5 millimeters to about 25 millimeters, more preferably about 8 millimeters to about 25 millimeters, and even more preferably about 10 millimeters to about 25 millimeters. In other embodiments, the mouthpiece filter segment preferably has a length of about 5 millimeters to about 10 millimeters, more preferably about 8 millimeters to about 20 millimeters, and even more preferably about 10 millimeters to about 20 millimeters. In further embodiments, the mouthpiece filter segment preferably has a length of about 5 millimeters to about 15 millimeters, more preferably about 8 millimeters to about 15 millimeters, and even more preferably about 10 millimeters to about 15 millimeters.

[0317] For example, the mouthpiece filter segment may have a length of about 5 millimeters to about 25 millimeters, or about 8 millimeters to about 20 millimeters, or about 10 millimeters to about 15 millimeters. In a preferred embodiment, the mouthpiece filter segment has a length of approximately 12 millimeters.

[0318] In certain preferred embodiments of the present invention, the mouthpiece filter segment has a length of at least 10 millimeters. In such embodiments, the mouthpiece filter segment is therefore relatively long compared to mouthpiece filter segments provided in prior art articles. Providing a relatively long mouthpiece filter segment in the aerosol-generating article of the present invention can provide several benefits to consumers. The mouthpiece filter segment is typically more resilient to deformation or better adapted to recover its original shape after deformation than other elements that may be provided downstream of the rod of the aerosol-generating substrate, such as an aerosol cooling element or a support element. Thus, increasing the length of the mouthpiece filter segment has been found to provide improved grip by the consumer and facilitate insertion of the aerosol-generating article into a heating device. Longer mouthpieces can be additionally used to provide higher levels of filtration and removal of undesirable aerosol components such as phenol, thereby delivering a higher quality aerosol. Furthermore, the use of longer mouthpiece filter segments allows for more complex mouthpieces to be provided, as there is more space to incorporate mouthpiece components such as capsules, threads, and restrictors.

[0319] In particularly preferred embodiments of the present invention, a mouthpiece filter segment having a length of at least 10 millimeters is combined with a relatively short aerosol cooling element, for example, an aerosol cooling element having a length of less than 10 millimeters. This combination has been found to reduce the risk of deformation of the aerosol cooling element during use and provide a more rigid mouthpiece, contributing to a more efficient puffing action by the consumer.

[0320] The length of the mouthpiece filter segment is at least 0.30 times the total length of the intermediate hollow section, preferably at least 0.40 times the total length of the intermediate hollow section, more preferably at least 0.50 times the total length of the intermediate hollow section, even more preferably at least 0.60 times the total length of the intermediate hollow section, and most preferably at least 0.75 times the length of the intermediate hollow section. Thus, the ratio of the length of the mouthpiece filter segment to the total length of the intermediate hollow section is at least about 0.30, preferably at least about 0.40, more preferably at least about 0.50, even more preferably at least about 0.60, and most preferably at least about 0.75.

[0321] The ratio of the length of the mouthpiece filter segment to the length of the rod of the aerosol-generating substrate may be from about 0.40 to about 1.50.

[0322] The ratio of the length of the mouthpiece filter segment to the length of the rod of the aerosol-generating substrate is preferably at least about 0.40, more preferably at least about 0.60, even more preferably at least about 0.70, and most preferably at least about 0.80. In preferred embodiments, the ratio of the length of the mouthpiece filter segment to the length of the rod of the aerosol-generating substrate is less than about 1.40, more preferably less than about 1.30, and even more preferably less than about 1.20.

[0323] In some embodiments, the ratio of the length of the mouthpiece filter segment to the length of the rod of the aerosol-generating substrate is preferably about 0.40 to about 1.40, more preferably about 0.60 to about 1.40, even more preferably about 0.70 to about 1.40, and most preferably about 0.80 to about 1.40. In other embodiments, the ratio of the length of the mouthpiece filter segment to the length of the rod of the aerosol-generating substrate is preferably about 0.40 to about 1.30, more preferably about 0.60 to about 1.30, even more preferably about 0.70 to about 1.30, and most preferably about 0.80 to about 1.30. In further embodiments, the ratio of the length of the mouthpiece filter segment to the length of the rod of the aerosol-generating substrate is about 0.40 to about 1.20, more preferably about 0.60 to about 1.20, even more preferably about 0.70 to about 1.20, and most preferably about 0.80 to about 1.20.

[0324] In a particularly preferred embodiment, the ratio of the length of the mouthpiece filter segment to the length of the rod of the aerosol-generating substrate is about 1.00, and in another particularly preferred embodiment, the ratio of the length of the mouthpiece filter segment to the length of the rod of the aerosol-generating substrate is about 0.42.

[0325] The ratio of the length of the mouthpiece filter segment to the overall length of the aerosol-generating article may be from about 0.11 to about 0.35.

[0326] Preferably, the ratio of the length of the mouthpiece filter segment to the overall length of the aerosol-generating article is at least about 0.11, more preferably at least about 0.22, even more preferably at least about 0.24, and most preferably at least about 0.26. Preferably, the ratio of the length of the mouthpiece filter segment to the overall length of the aerosol-generating article is less than about 0.34, more preferably less than about 0.32, and even more preferably less than about 0.3.

[0327] In some embodiments, the ratio of the length of the mouthpiece filter segment to the overall length of the aerosol-generating article substrate is preferably about 0.11 to about 0.34, more preferably about 0.22 to about 0.34, even more preferably about 0.24 to about 0.34, and most preferably about 0.26 to about 0.34. In other embodiments, the ratio of the length of the mouthpiece filter segment to the overall length of the aerosol-generating article substrate is preferably about 0.11 to about 0.32, more preferably about 0.22 to about 0.32, even more preferably about 0.24 to about 0.32, and most preferably about 0.26 to about 0.32. In further embodiments, the ratio of the length of the mouthpiece filter segment to the overall length of the aerosol-generating article substrate is preferably about 0.11 to about 0.3, more preferably about 0.22 to about 0.3, even more preferably about 0.24 to about 0.3, and most preferably about 0.26 to about 0.3.

[0328] In a particularly preferred embodiment, the ratio of the length of the mouthpiece filter segment to the overall length of the aerosol-generating article is about 0.27. In another particularly preferred embodiment, the ratio of the length of the mouthpiece filter to the overall length of the aerosol-generating article is about 0.11.

[0329] The rod-shaped aerosol-generating element of the present invention comprises an aerosol-generating substrate, which comprises an aerosol-generating film, which comprises one or more cellulosic film-forming agents and one or more aerosol formers.

[0330] The aerosol-generating film may remain solid when heated to temperatures between 180° C. and 350° C. This may advantageously reduce or eliminate crusting of the aerosol-generating article, as explained further below.

[0331] For example, the aerosol-generating film may remain solid when heated to a temperature between 200 degrees Celsius and 320 degrees Celsius, between 220 degrees Celsius and 300 degrees Celsius, or between 240 degrees Celsius and 280 degrees Celsius.

[0332] As used herein, the term "film" is used to describe a solid aerosol-generating substrate having a thickness that is substantially less than its width or length.

[0333] As used herein, the term "exposed surface area of ​​the film" refers to the cumulative surface area of ​​the various surfaces of the aerosol-generating film that may be exposed to gaseous airflow through an aerosol-generating article containing the film during use.

[0334] The "weight" of the aerosol-generating film of the aerosol-generating article according to the present invention generally corresponds to the weight of the components of the corresponding film-forming composition minus the weight of the water evaporated during the drying process. If the film is self-supporting, it can be weighed by itself. If the film is placed on a support, the film and the support are weighed, and the weight of the support measured before the film is placed is subtracted from the total weight of the film and the support.

[0335] Unless otherwise stated, the weight percentages of the components of the aerosol-generating film listed herein are based on the total weight of the aerosol-generating film.

[0336] As used herein, the term "thickness" is used to describe the smallest dimension between opposing, substantially parallel surfaces of an aerosol-generating film. The thickness of an aerosol-generating film may substantially correspond to the thickness at which the corresponding film-forming composition was cast or extruded, because the cast or extruded film-forming composition does not substantially shrink during drying despite loss of water.

[0337] The aerosol-generating film may have a thickness of 0.05 millimeters or more, 0.1 millimeters or more, 0.2 millimeters or more, or 0.3 millimeters or more.

[0338] The aerosol-generating film may have a thickness of 1.2 millimeters or less, 1 millimeter or less, 0.8 millimeters or less, 0.6 millimeters or less, or 0.4 millimeters or less.

[0339] The aerosol-generating film may have a thickness of 0.05 millimeters to 1.2 millimeters, 0.05 millimeters to 1 millimeter, 0.05 millimeters to 0.8 millimeters, 0.05 millimeters to 0.6 millimeters, or 0.05 millimeters to 0.4 millimeters.

[0340] The aerosol-generating film may have a thickness of 0.1 millimeters to 1.2 millimeters, 0.1 millimeters to 1 millimeter, 0.1 millimeters to 0.8 millimeters, 0.1 millimeters to 0.6 millimeters, or 0.1 millimeters to 0.4 millimeters.

[0341] The aerosol-generating film may have a thickness of 0.2 millimeters to 1.2 millimeters, 0.2 millimeters to 1 millimeter, 0.2 millimeters to 0.8 millimeters, 0.2 millimeters to 0.6 millimeters, or 0.2 millimeters to 0.4 millimeters.

[0342] The aerosol-generating film may have a thickness of 0.3 millimeters to 1.2 millimeters, 0.3 millimeters to 1 millimeter, 0.3 millimeters to 0.8 millimeters, 0.3 millimeters to 0.6 millimeters, or 0.3 millimeters to 0.4 millimeters.

[0343] The aerosol-generating film may have a basis weight of 85 grams per square meter or more, 100 grams per square meter or more, 120 grams per square meter or more, or 140 grams per square meter or more.

[0344] The aerosol-generating film may have a basis weight of 300 grams per square meter or less, 280 grams per square meter or less, or 260 grams per square meter or less.

[0345] The aerosol-generating film may have a basis weight of 85 grams per square meter to 300 grams per square meter, 85 grams per square meter to 280 grams per square meter, or 85 grams per square meter to 260 grams per square meter.

[0346] The aerosol-generating film may have a basis weight of from 100 grams per square meter to 300 grams per square meter, from 100 grams per square meter to 280 grams per square meter, or from 100 grams per square meter to 260 grams per square meter.

[0347] The aerosol-generating film may have a basis weight of 120 grams per square meter to 300 grams per square meter, 120 grams per square meter to 280 grams per square meter, or 120 grams per square meter to 260 grams per square meter.

[0348] The aerosol-generating film may have a basis weight of 140 grams per square meter to 300 grams per square meter, 140 grams per square meter to 280 grams per square meter, or 140 grams per square meter to 260 grams per square meter.

[0349] The aerosol-generating film may be formed by any suitable method, for example, the aerosol-generating film may be formed by batch casting, continuous casting, or extrusion.

[0350] The aerosol-generating film may be self-supporting, that is, the properties of the aerosol-generating film may be such that it can be separated from a supporting surface, even if the aerosol-generating film is formed by casting a slurry onto the supporting surface.

[0351] The aerosol-generating film may be disposed on a support, or may be sandwiched between other materials, which may enhance the mechanical stability of the aerosol-generating film. For example, the aerosol-generating film may be disposed on a layered support.

[0352] The aerosol-generating film may be cut or otherwise divided into a plurality of strips or pieces that can be rolled up to form an aerosol-generating rod for inclusion in an aerosol-generating article.

[0353] The aerosol-generating films may be assembled to form an aerosol-generating rod for inclusion in an aerosol-generating article.

[0354] The aerosol-generating film may be textured, which may facilitate crimping the aerosol-generating film to form an aerosol-generating rod for inclusion in an aerosol-generating article.

[0355] The term "textured" is used to describe an aerosol-generating film that is crimped, embossed, debossed, perforated, or otherwise modified. A textured aerosol-generating film may include a plurality of spaced indentations, protrusions, perforations, or a combination thereof.

[0356] The aerosol-generating film may be crimped.

[0357] As used herein, the term "crimped" is intended to be synonymous with the term "crinkled" and is used to describe an aerosol-generating film having a plurality of substantially parallel ridges or corrugations.

[0358] The crimped aerosol-generating film may have a plurality of ridges or corrugations substantially parallel to the cylindrical axis of the aerosol-generating rod, which may advantageously facilitate assembling the crimped aerosol-generating film to form the aerosol-generating rod.

[0359] The aerosol-generating film may be textured using suitable known machinery for texturing filter tow, paper and other materials.

[0360] The aerosol-generating film may be crimped using a crimping unit of the type described in CH-A-691156, which includes a pair of rotatable crimping rollers, although it will be appreciated that the aerosol-generating film may also be textured using other suitable machinery and processes that deform or perforate the aerosol-generating film.

[0361] The aerosol-generating film may be incorporated directly into an aerosol-generating rod for inclusion in an aerosol-generating article.

[0362] The aerosol-generating film may be applied to a layered substrate before being incorporated into an aerosol-generating rod for inclusion in an aerosol-generating article. For example, the aerosol-generating film may be applied to the surface of a sheet material. Sheet materials suitable for use as a layered substrate include, but are not limited to, paper, cardboard, and homogenized plant material. For example, the aerosol-generating film may be applied to a paper sheet, an aluminum-coated paper sheet, or a polyethylene-coated paper sheet.

[0363] The layered substrate to which the aerosol-generating film is applied may be cut or otherwise divided into a plurality of strips or pieces, as described above.

[0364] The layered substrate to which the aerosol-generating film is applied may be assembled as described above.

[0365] The layered substrate to which the aerosol-generating film is applied may be textured as described above.

[0366] The aerosol-generating film may be applied to a tubular support prior to incorporation into an aerosol-generating rod for inclusion in an aerosol-generating article, for example, the aerosol-generating film may be applied to the inner surface of a hollow tubular support.

[0367] Preferably, the aerosol-generating film may include nicotine.

[0368] As used herein, the term "nicotine" is used to refer to nicotine, nicotine base, or nicotine salt. In some embodiments where the aerosol-generating film may include nicotine base or nicotine salt, the amount of nicotine recited herein is the amount of free base nicotine or the amount of protonated nicotine, respectively.

[0369] The aerosol-generating film may contain natural nicotine, or synthetic nicotine, or a combination of natural and synthetic nicotine.

[0370] The nicotine may comprise one or more nicotine salts selected from the list consisting of nicotine lactate, nicotine citrate, nicotine pyruvate, nicotine bitartrate, nicotine benzoate, nicotine pectinate, nicotine alginate, and nicotine salicylate.

[0371] The nicotine may comprise an extract of tobacco.

[0372] The aerosol-generating film may have a nicotine content of 0.5 weight percent or more, 1 weight percent or more, 1.5 weight percent or more, or 2 weight percent or more.

[0373] The aerosol-generating film may have a nicotine content of 10 weight percent or less, 8 weight percent or less, 6 weight percent or less, or 4 weight percent or less.

[0374] The aerosol-generating film may have a nicotine content of from 0.5 weight percent to 10 weight percent, from 0.5 weight percent to 8 weight percent, from 0.5 weight percent to 6 weight percent, or from 0.5 weight percent to 4 weight percent.

[0375] The aerosol-generating film may have a nicotine content of from 1 weight percent to 10 weight percent, from 1 weight percent to 8 weight percent, from 1 weight percent to 6 weight percent, or from 1 weight percent to 4 weight percent.

[0376] The aerosol-generating film may have a nicotine content of from 1.5 weight percent to 10 weight percent, from 1.5 weight percent to 8 weight percent, from 1.5 weight percent to 6 weight percent, or from 1.5 weight percent to 4 weight percent.

[0377] The aerosol-generating film may have a nicotine content of from 2 weight percent to 10 weight percent, from 2 weight percent to 8 weight percent, from 2 weight percent to 6 weight percent, or from 2 weight percent to 4 weight percent.

[0378] The aerosol-generating film includes one or more aerosol formers.

[0379] As used herein, the term "aerosol former" is used to describe a compound that, in use, facilitates the formation of an aerosol and that is preferably substantially resistant to thermal decomposition at the operating temperatures of the aerosol-generating article or aerosol-generating system that includes the aerosol-generating film.

[0380] Examples of suitable aerosol formers include polyhydric alcohols (such as 1,3-butanediol, glycerin, 1,3-propanediol, propylene glycol, and triethylene glycol), esters of polyhydric alcohols (such as glycerol monoacetate, diacetate, or triacetate), and aliphatic esters of mono-, di-, or polycarboxylic acids (such as dimethyl dodecanedioate and dimethyl tetradecanedioate).

[0381] Preferably, the one or more aerosol formers comprise one or more polyhydric alcohols selected from 1,3-butanediol, glycerin, 1,3-propanediol, propylene glycol, and triethylene glycol.

[0382] More preferably, the one or more aerosol formers comprise one or more polyhydric alcohols selected from glycerin and propylene glycol. Even more preferably, the one or more aerosol formers comprise glycerin.

[0383] Most preferably, the one or more aerosol formers may be glycerin.

[0384] The aerosol-generating film may have a total aerosol-former content of 45 weight percent or greater.

[0385] The term "total aerosol former content" is used to describe the combined content of all aerosol formers in an aerosol-generating film.

[0386] The aerosol-generating film may have a total aerosol-former content of 46 weight percent or greater, 48 weight percent or greater, 50 weight percent or greater, or 52 weight percent or greater.

[0387] The aerosol-generating film may have a total aerosol-former content of 62 weight percent or less, 60 weight percent or less, 58 weight percent or less, 56 weight percent or less, or 54 weight percent or less.

[0388] The aerosol-generating film may have a total aerosol-former content of 45 weight percent to 62 weight percent, 45 weight percent to 60 weight percent, 45 weight percent to 58 weight percent, 45 weight percent to 56 weight percent, or 45 weight percent to 54 weight percent.

[0389] The aerosol-generating film may have a total aerosol-former content of 46 weight percent to 62 weight percent, 46 weight percent to 60 weight percent, 46 weight percent to 58 weight percent, 46 weight percent to 56 weight percent, or 46 weight percent to 54 weight percent.

[0390] The aerosol-generating film may have a total aerosol-former content of 48 weight percent to 62 weight percent, 48 weight percent to 60 weight percent, 48 weight percent to 58 weight percent, 48 weight percent to 56 weight percent, or 48 weight percent to 54 weight percent.

[0391] The aerosol-generating film may have a total aerosol-former content of 50 weight percent to 62 weight percent, 50 weight percent to 60 weight percent, 50 weight percent to 58 weight percent, 50 weight percent to 56 weight percent, or 50 weight percent to 54 weight percent.

[0392] The aerosol-generating film may have a total aerosol-former content of 52 weight percent to 62 weight percent, 52 weight percent to 60 weight percent, 52 weight percent to 58 weight percent, 52 weight percent to 56 weight percent, or 52 weight percent to 54 weight percent.

[0393] Preferably, the aerosol-generating film may include one or more polyhydric alcohols.

[0394] The aerosol-generating film may have a total polyhydric alcohol content of 45 weight percent or greater, 46 weight percent or greater, 48 weight percent or greater, 50 weight percent or greater, or 52 weight percent or greater.

[0395] The term "total polyhydric alcohol content" is used to describe the combined content of all polyhydric alcohols in the aerosol-generating film.

[0396] The aerosol-generating film may have a total polyhydric alcohol content of 62 weight percent or less, 60 weight percent or less, 58 weight percent or less, 56 weight percent or less, or 54 weight percent or less.

[0397] The aerosol-generating film may have a total polyhydric alcohol content of 45 weight percent to 62 weight percent, 45 weight percent to 60 weight percent, 45 weight percent to 58 weight percent, 45 weight percent to 56 weight percent, or 45 weight percent to 54 weight percent.

[0398] The aerosol-generating film may have a total polyhydric alcohol content of 46 weight percent to 62 weight percent, 46 weight percent to 60 weight percent, 46 weight percent to 58 weight percent, 46 weight percent to 56 weight percent, or 46 weight percent to 54 weight percent.

[0399] The aerosol-generating film may have a total polyhydric alcohol content of 48 weight percent to 62 weight percent, 48 weight percent to 60 weight percent, 48 weight percent to 58 weight percent, 48 weight percent to 56 weight percent, or 48 weight percent to 54 weight percent.

[0400] The aerosol-generating film may have a total polyhydric alcohol content of 50 to 62 weight percent, 50 to 60 weight percent, 50 to 58 weight percent, 50 to 56 weight percent, or 50 to 54 weight percent.

[0401] The aerosol-generating film may have a total polyhydric alcohol content of 52 weight percent to 62 weight percent, 52 weight percent to 60 weight percent, 52 weight percent to 58 weight percent, 52 weight percent to 56 weight percent, or 52 weight percent to 54 weight percent.

[0402] The aerosol-generating film preferably comprises one or more polyhydric alcohols selected from 1,3-butanediol, glycerin, 1,3-propanediol, propylene glycol, and triethylene glycol.

[0403] More preferably, the aerosol-generating film comprises one or more polyhydric alcohols selected from glycerin and propylene glycol.

[0404] Most preferably, the aerosol-generating film comprises glycerin.

[0405] The aerosol-generating film may have a glycerin content of 35 weight percent or more, 40 weight percent or more, 45 weight percent or more, 46 weight percent or more, 48 weight percent or more, 50 weight percent or more, or 52 weight percent or more.

[0406] The aerosol-generating film may have a glycerin content of 62 weight percent or less, 60 weight percent or less, 58 weight percent or less, 56 weight percent or less, or 54 weight percent or less.

[0407] The aerosol-generating film may have a glycerin content of 35 weight percent to 62 weight percent, 35 weight percent to 60 weight percent, 35 weight percent to 58 weight percent, 35 weight percent to 56 weight percent, or 35 weight percent to 54 weight percent.

[0408] The aerosol-generating film may have a total glycerin content of 40 weight percent to 62 weight percent, 40 weight percent to 60 weight percent, 40 weight percent to 58 weight percent, 40 weight percent to 56 weight percent, or 40 weight percent to 54 weight percent.

[0409] The aerosol-generating film may have a glycerin content of 45 weight percent to 62 weight percent, 45 weight percent to 60 weight percent, 45 weight percent to 58 weight percent, 45 weight percent to 56 weight percent, or 45 weight percent to 54 weight percent.

[0410] The aerosol-generating film may have a glycerin content of 46 weight percent to 62 weight percent, 46 weight percent to 60 weight percent, 46 weight percent to 58 weight percent, 46 weight percent to 56 weight percent, or 46 weight percent to 54 weight percent.

[0411] The aerosol-generating film may have a glycerin content of 48 weight percent to 62 weight percent, 48 weight percent to 60 weight percent, 48 weight percent to 58 weight percent, 48 weight percent to 56 weight percent, or 48 weight percent to 54 weight percent.

[0412] The aerosol-generating film may have a total glycerin content of 50 to 62 weight percent, 50 to 60 weight percent, 50 to 58 weight percent, 50 to 56 weight percent, or 50 to 54 weight percent.

[0413] The aerosol-generating film may have a total glycerin content of 52 weight percent to 62 weight percent, 52 weight percent to 60 weight percent, 52 weight percent to 58 weight percent, 52 weight percent to 56 weight percent, or 52 weight percent to 54 weight percent.

[0414] The aerosol-generating film may preferably include one or more carboxylic acids.

[0415] The aerosol-generating film may comprise multiple carboxylic acids, i.e., the aerosol-generating film may comprise two or more carboxylic acids, for example, the aerosol-generating film may comprise two carboxylic acids, three carboxylic acids, four carboxylic acids, or five carboxylic acids.

[0416] It has surprisingly been found that by including one or more carboxylic acids in the aerosol-generating film of an aerosol-generating article, the stability of the aerosol-generating film during storage of the aerosol-generating article can be advantageously improved. It has surprisingly been found that by including one or more carboxylic acids in the aerosol-generating film of an aerosol-generating article, the stability of nicotine in the aerosol-generating film during storage of the aerosol-generating article can be advantageously improved. In particular, it has surprisingly been found that by including one or more carboxylic acids in the aerosol-generating film of an aerosol-generating article, the corrosion of components of the aerosol-generating article can be advantageously inhibited. In particular, it has surprisingly been found that by including one or more carboxylic acids in the aerosol-generating film of an aerosol-generating article, the corrosion of metal components of the aerosol-generating article can be advantageously inhibited. In some embodiments, the susceptor may be in direct contact with the aerosol-generating substrate.

[0417] Without wishing to be bound by theory, it is believed that when included in an aerosol-generating film, carboxylic acids that do not contain non-carboxyl alkyl hydroxyl groups are less likely to oxidize other components of the aerosol-generating article than carboxylic acids that contain non-carboxyl alkyl hydroxyl groups. Without wishing to be bound by theory, it is believed that when included in an aerosol-generating film, carboxylic acids that do not contain ketone groups are less likely to oxidize other components of the aerosol-generating article than carboxylic acids that contain ketone groups. It is believed that including one or more carboxylic acids that do not contain non-carboxyl alkyl hydroxyl groups and do not contain ketone groups in the aerosol-generating film thereby inhibits corrosion of the components of the aerosol-generating article.

[0418] Without wishing to be bound by theory, it is believed that carboxylic acids having a pKa of 3.5 or less, when included in the aerosol-generating film, are less likely to oxidize other components of the aerosol-generating article than carboxylic acids having a pKa greater than 3.5. It is believed that the inclusion of one or more carboxylic acids having a pKa of 3.5 or less in the aerosol-generating film thereby inhibits corrosion of the components of the aerosol-generating article.

[0419] The aerosol-generating film may contain one or more carboxylic acids that (i) contain no non-carboxyl alkyl hydroxyl groups and no ketone groups, or (ii) have a pKa in water of 3.5 or less at 25°C, or (iii) contain no non-carboxyl alkyl hydroxyl groups, no ketone groups, and have a pKa in water of 3.5 or less at 25°C.

[0420] The aerosol-generating film may include a plurality of carboxylic acids that are free of non-carboxyl alkyl hydroxyl groups and free of ketone groups. For example, the aerosol-generating film may include benzoic acid and succinic acid.

[0421] The aerosol-generating film may include one or more carboxylic acids having a pKa in water at 25°C of 3.5 or less.

[0422] As used herein in connection with the present invention, the term "carboxylic acid having a pKa in water of 3.5 or less at 25°C" is used to describe monobasic carboxylic acids having a pKa in water of 3.5 or less at 25°C, and polybasic carboxylic acids having a pKa in water of 3.5 or less at 25°C.

[0423] For example, the aerosol-generating film may include one or more carboxylic acids selected from citric acid, fumaric acid, maleic acid, malic acid, oxalic acid, and salicylic acid.

[0424] The aerosol-generating film may include multiple carboxylic acids having a pKa in water of 3.5 or less at 25° C. For example, the aerosol-generating film may include citric acid and malic acid.

[0425] The aerosol-generating film may comprise one or more carboxylic acids that contain no non-carboxyl alkyl hydroxyl groups, no ketone groups, and have a pKa in water of 3.5 or less at 25° C. For example, the aerosol-generating film may comprise one or more carboxylic acids selected from fumaric acid, maleic acid, oxalic acid, and salicylic acid.

[0426] The aerosol-generating film may include a plurality of carboxylic acids that contain no non-carboxyl alkyl hydroxyl groups, no ketone groups, and have a pKa in water of 3.5 or less at 25° C. For example, the aerosol-generating film may include fumaric acid and maleic acid.

[0427] The aerosol-generating film may comprise one or more carboxylic acids having a pKa in water at 25°C of 3.6 or greater.

[0428] As used herein in connection with the present invention, the term "carboxylic acid having a pKa in water of 3.6 or greater at 25°C" is used to describe monobasic carboxylic acids having a pKa in water of 3.6 or greater at 25°C, and polybasic carboxylic acids having a pKa in water of 3.6 or greater at 25°C.

[0429] The aerosol-generating film may comprise one or more carboxylic acids that contain no non-carboxyl alkyl hydroxyl groups, no ketone groups, and have a pKa in water of 3.6 or greater at 25° C. For example, the aerosol-generating film may comprise one or more carboxylic acids selected from acetic acid, adipic acid, benzoic acid, and succinic acid.

[0430] The aerosol-generating film may include a plurality of carboxylic acids that contain no non-carboxyl alkyl hydroxyl groups, no ketone groups, and have a pKa in water of 3.6 or greater at 25° C. For example, the aerosol-generating film may include acetic acid and benzoic acid.

[0431] The aerosol-generating film may further comprise one or more carboxylic acids that contain non-carboxyl alkyl hydroxyl groups and have a pKa in water of 3.6 or greater at 25° C. For example, the aerosol-generating film may further comprise lactic acid.

[0432] The aerosol-generating film may further comprise one or more carboxylic acids that contain a ketone group and have a pKa in water of 3.6 or greater at 25° C. For example, the aerosol-generating film may further comprise levulinic acid.

[0433] The aerosol-generating film may include multiple carboxylic acids that have a pKa in water of 3.6 or greater at 25° C. For example, the aerosol-generating film may include benzoic acid and lactic acid.

[0434] The aerosol-generating film may comprise one or more carboxylic acids having a pKa in water at 25°C of 3.5 or less, and one or more carboxylic acids having a pKa in water at 25°C of 3.6 or more.

[0435] For example, the aerosol-generating film may include one or more carboxylic acids selected from fumaric acid, maleic acid, and malic acid, and one or more carboxylic acids selected from acetic acid, benzoic acid, lactic acid, and levulinic acid.

[0436] For example, the aerosol-generating film may include fumaric acid and one or more carboxylic acids selected from acetic acid, benzoic acid, lactic acid, and levulinic acid.

[0437] The aerosol-generating film may comprise one or more carboxylic acids selected from acetic acid, adipic acid, benzoic acid, citric acid, fumaric acid, maleic acid, malic acid, myristic acid, oxalic acid, salicylic acid, stearic acid, succinic acid, undecanoic acid, and C1-C10 saturated alkyl monocarboxylic acids.

[0438] The aerosol-generating film may include one or more carboxylic acids selected from acetic acid, adipic acid, benzoic acid, citric acid, fumaric acid, maleic acid, malic acid, myristic acid, oxalic acid, salicylic acid, stearic acid, succinic acid, and undecanoic acid.

[0439] The aerosol-generating film may include one or more carboxylic acids selected from acetic acid, adipic acid, benzoic acid, citric acid, fumaric acid, maleic acid, myristic acid, oxalic acid, salicylic acid, stearic acid, succinic acid, and undecanoic acid.

[0440] The aerosol-generating film may include one or more carboxylic acids selected from acetic acid, benzoic acid, citric acid, fumaric acid, maleic acid, and malic acid.

[0441] The aerosol-generating film may include one or more carboxylic acids selected from acetic acid, benzoic acid, citric acid, fumaric acid, and maleic acid.

[0442] The aerosol-generating film may include one or more carboxylic acids selected from fumaric acid, maleic acid, and malic acid.

[0443] Preferably, the aerosol-generating film comprises one or more carboxylic acids selected from fumaric acid and maleic acid.

[0444] More preferably, the aerosol-generating film comprises fumaric acid.

[0445] The aerosol-generating film may further comprise one or more carboxylic acids selected from lactic acid and levulinic acid. Advantageously, the inclusion of one or more carboxylic acids in the aerosol-generating substrate may result in the formation of nicotine salts. Advantageously, the inventors have discovered that lactic acid and levulinic acid are particularly good carboxylic acids for forming nicotine salts.

[0446] The aerosol-generating film has a total carboxylic acid content of 0.5 weight percent or greater.

[0447] The term "total carboxylic acid content" is used to describe the combined content of all carboxylic acids in an aerosol-generating film. For example, if an aerosol-generating film contains carboxylic acids consisting of benzoic acid and fumaric acid, the term "total carboxylic acid content" describes the combined benzoic acid and fumaric acid content of the aerosol-generating film.

[0448] The aerosol-generating film may have a total carboxylic acid content of 1 weight percent or greater, 1.5 weight percent or greater, or 2 weight percent or greater.

[0449] The aerosol-generating film may have a total carboxylic acid content of 8 weight percent or less, 6 weight percent or less, or 4 weight percent or less.

[0450] The aerosol-generating film may have a total carboxylic acid content of 0.5 weight percent to 8 weight percent, 0.5 weight percent to 6 weight percent, or 0.5 weight percent to 4 weight percent.

[0451] The aerosol-generating film may have a total carboxylic acid content of from 1 weight percent to 8 weight percent, from 1 weight percent to 6 weight percent, or from 1 weight percent to 4 weight percent.

[0452] The aerosol-generating film may have a total carboxylic acid content of 1.5 weight percent to 8 weight percent, 1.5 weight percent to 6 weight percent, or 1.5 weight percent to 4 weight percent.

[0453] The aerosol-generating film may have a total carboxylic acid content of 2 weight percent to 8 weight percent, 2 weight percent to 6 weight percent, or 2 weight percent to 4 weight percent.

[0454] The molar ratio of total carboxylic acids to nicotine in the aerosol-generating film may be 0.5:1 or greater, 1:1 or greater, 1.5:1 or greater, or 2:1 or greater.

[0455] The molar ratio of total carboxylic acids to nicotine in the aerosol-generating film may be 5:1 or less, 4.5:1 or less, 4:1 or less, or 3.5:1 or less.

[0456] The molar ratio of total carboxylic acid to nicotine in the aerosol-generating film may be from 0.5:1 to 5:1, from 0.5:1 to 4.5:1, from 0.5:1 to 4:1, or from 0.5:1 to 3.5:1.

[0457] The molar ratio of total carboxylic acids to nicotine in the aerosol-generating film may be from 1:1 to 5:1, from 1:1 to 4.5:1, from 1:1 to 4:1, or from 1:1 to 3.5:1.

[0458] The molar ratio of total carboxylic acid to nicotine in the aerosol-generating film may be from 1.5:1 to 5:1, from 1.5:1 to 4.5:1, from 1.5:1 to 4:1, or from 1.5:1 to 3.5:1.

[0459] The molar ratio of total carboxylic acids to nicotine in the aerosol-generating film may be from 2:1 to 5:1, from 2:1 to 4.5:1, from 2:1 to 4:1, or from 2:1 to 3.5:1.

[0460] The aerosol-generating film may have a fumaric acid content of 0.5 weight percent or greater, 1 weight percent or greater, 1.5 weight percent or greater, or 2 weight percent or greater.

[0461] The aerosol-generating film may have a fumaric acid content of 8 weight percent or less, 6 weight percent or less, or 4 weight percent or less.

[0462] The aerosol-generating film may have a fumaric acid content of 0.5 weight percent to 8 weight percent, 0.5 weight percent to 6 weight percent, or 0.5 weight percent to 4 weight percent.

[0463] The aerosol-generating film may have a fumaric acid content of from 1 weight percent to 8 weight percent, from 1 weight percent to 6 weight percent, or from 1 weight percent to 4 weight percent.

[0464] The aerosol-generating film may have a fumaric acid content of 1.5 weight percent to 8 weight percent, 1.5 weight percent to 6 weight percent, or 1.5 weight percent to 4 weight percent.

[0465] The aerosol-generating film may have a fumaric acid content of 2 weight percent to 8 weight percent, 2 weight percent to 6 weight percent, or 2 weight percent to 4 weight percent.

[0466] The molar ratio of fumaric acid to nicotine in the aerosol-generating film may be 0.5:1 or greater, 1:1 or greater, 1.5:1 or greater, or 2:1 or greater.

[0467] The molar ratio of fumaric acid to nicotine in the aerosol-generating film may be 4:1 or less, or 3.5:1 or less, or 3:1 or less, or 2.5:1 or less.

[0468] The molar ratio of fumaric acid to nicotine in the aerosol-generating film may be from 0.5:1 to 4:1, from 0.5:1 to 3.5:1, from 0.5:1 to 3:1, or from 0.5:1 to 2.5:1.

[0469] The molar ratio of fumaric acid to nicotine in the aerosol-generating film may be 1:1 to 4:1, 1:1 to 3.5:1, 1:1 to 3:1, or 1:1 to 2.5:1.

[0470] The molar ratio of fumaric acid to nicotine in the aerosol-generating film may be from 1.5:1 to 4:1, from 1.5:1 to 3.5:1, from 1.5:1 to 3:1, or from 1.5:1 to 2.5:1.

[0471] The molar ratio of fumaric acid to nicotine in the aerosol-generating film may be 2:1 to 4:1, 2:1 to 3.5:1, 2:1 to 3:1, or 2:1 to 2.5:1.

[0472] The aerosol-generating film comprises one or more cellulosic film-forming agents.

[0473] The term "cellulosic film former" is used to denote a cellulose polymer that has the ability to form a continuous film by itself or in the presence of an auxiliary thickener.

[0474] Advantageously, the aerosol-generating film may comprise one or more cellulosic film-forming agents selected from carboxymethyl cellulose (CMC), ethyl cellulose (EC), hydroxyethyl cellulose (HEC), hydroxyethyl methyl cellulose (HEMC), hydroxypropyl cellulose (HPC), hydroxypropyl methyl cellulose (HPMC), and methyl cellulose (MC).

[0475] More advantageously, the aerosol-generating film may comprise one or more cellulosic film-forming agents selected from carboxymethylcellulose (CMC), ethylcellulose (EC), methylcellulose (MC), and hydroxypropylmethylcellulose (HPMC).

[0476] Most advantageously, the aerosol-generating film comprises one or more cellulosic film-forming agents selected from carboxymethylcellulose (CMC) and hydroxypropylmethylcellulose (HPMC).

[0477] Preferably, the aerosol-generating film comprises carboxymethylcellulose (CMC) and hydroxypropylmethylcellulose (HPMC).

[0478] Most preferably, the aerosol-generating film comprises hydroxypropyl methylcellulose (HPMC).

[0479] One or more cellulosic film-forming agents may act as binders in the aerosol-generating film.

[0480] The aerosol-generating film may have a total cellulosic film-forming agent content of 15 weight percent or more, 20 weight percent or more, or 25 weight percent or more.

[0481] As used herein, the term "total cellulosic film-forming agent content" is used to describe the combined content of all cellulosic film-forming agents in the aerosol-generating film.

[0482] The aerosol-generating film may have a total cellulosic film-forming agent content of 40 weight percent or less, 35 weight percent or less, or 30 weight percent or less.

[0483] The aerosol-generating film may have a total cellulosic film-forming agent content of 15 weight percent to 40 weight percent, 15 weight percent to 35 weight percent, or 15 weight percent to 30 weight percent.

[0484] The aerosol-generating film may have a total cellulosic film-forming agent content of 20 weight percent to 40 weight percent, 20 weight percent to 35 weight percent, or 20 weight percent to 30 weight percent.

[0485] The aerosol-generating film may have a total cellulosic film-forming agent content of 25 weight percent to 40 weight percent, 25 weight percent to 35 weight percent, or 25 weight percent to 30 weight percent.

[0486] The inclusion of hydroxypropyl methylcellulose in the aerosol-generating film may advantageously facilitate the manufacture of the aerosol-generating film. For example, hydroxypropyl methylcellulose may advantageously reduce the overall viscosity of the slurry of the aerosol-generating film components produced during the manufacture of the solid aerosol-generating substrate. A low-viscosity slurry may be more flowable and easier to mix, transfer, and process during the manufacturing process.

[0487] Hydroxypropyl methylcellulose can advantageously act as a binder in the aerosol-generating film.

[0488] The aerosol-generating film may have a hydroxypropyl methylcellulose content of 14 weight percent or greater, 16 weight percent or greater, 18 weight percent or greater, or 20 weight percent or greater.

[0489] The aerosol-generating film may have a hydroxypropyl methylcellulose content of 40 weight percent or less, 35 weight percent or less, 30 weight percent or less, or 25 weight percent or less.

[0490] The aerosol-generating film may have a hydroxypropyl methylcellulose content of 14 weight percent to 40 weight percent, 14 weight percent to 35 weight percent, 14 weight percent to 30 weight percent, or 14 weight percent to 25 weight percent.

[0491] The aerosol-generating film may have a hydroxypropyl methylcellulose content of 16 weight percent to 40 weight percent, 16 weight percent to 35 weight percent, 16 weight percent to 30 weight percent, or 16 weight percent to 25 weight percent.

[0492] The aerosol-generating film may have a hydroxypropyl methylcellulose content of 18 weight percent to 40 weight percent, 18 weight percent to 35 weight percent, 18 weight percent to 30 weight percent, or 18 weight percent to 25 weight percent.

[0493] The aerosol-generating film may have a hydroxypropyl methylcellulose content of 20 weight percent to 40 weight percent, 20 weight percent to 35 weight percent, 20 weight percent to 30 weight percent, or 20 weight percent to 25 weight percent.

[0494] The inclusion of carboxymethylcellulose in the aerosol-generating film may advantageously reduce or eliminate crusting in the aerosol-generating article.

[0495] As used herein, the term "crusting" is used to describe the formation of a solid layer on a component of an aerosol-generating article.

[0496] Crusting can occur due to components of the aerosol-generating film melting and then re-solidifying around components of the aerosol-generating article during use. Crusting can be a particular problem in aerosol-generating articles that contain a susceptor that is in direct contact with a solid aerosol-forming substrate. If a crust forms on the susceptor, the crusted susceptor may become ineffective at heating the aerosol-generating film. This can disadvantageously lead to one or both of reduced nicotine delivery to the user and reduced aerosol formation from the aerosol-generating film.

[0497] The aerosol-generating film may include sodium carboxymethylcellulose.

[0498] The aerosol-generating film may have a carboxymethylcellulose content of 2 weight percent or more, 3 weight percent or more, 4 weight percent or more, or 5 weight percent or more.

[0499] The aerosol-generating film may have a carboxymethylcellulose content of 12 weight percent or less, 10 weight percent or less, 8 weight percent or less, or 6 weight percent or less.

[0500] The aerosol-generating film may have a carboxymethylcellulose content of 2 to 12 weight percent, 2 to 10 weight percent, 2 to 8 weight percent, or 2 to 6 weight percent.

[0501] The aerosol-generating film may have a carboxymethylcellulose content of 3 weight percent to 12 weight percent, 3 weight percent to 10 weight percent, 3 weight percent to 8 weight percent, or 3 weight percent to 6 weight percent.

[0502] The aerosol-generating film may have a carboxymethylcellulose content of 4 weight percent to 12 weight percent, 4 weight percent to 10 weight percent, 4 weight percent to 8 weight percent, or 4 weight percent to 6 weight percent.

[0503] The aerosol-generating film may have a carboxymethylcellulose content of 5 to 12 weight percent, 5 to 10 weight percent, 5 to 8 weight percent, or 5 to 6 weight percent.

[0504] The term "cellulosic agent" is used to refer to a cellulose-based material. Examples of cellulose-based agents include the cellulose-based film-forming agents mentioned above, as well as cellulose-based reinforcing agents and cellulose-based binders.

[0505] The aerosol-generating film may comprise multiple cellulosic agents, at least one of which is a cellulosic film-forming agent. That is, the aerosol-generating film may comprise two or more cellulosic agents, at least one of which is a cellulosic film-forming agent. For example, the aerosol-generating film may comprise two, three, four, or five cellulosic agents, at least one of which is a cellulosic film-forming agent.

[0506] The aerosol-generating film may have a total cellulosic agent content of 25 weight percent or more, or 30 weight percent or more.

[0507] The term "total cellulosic film-forming agent content" is used to describe the combined content of all cellulosic film-forming agents in an aerosol-generating film. For example, if an aerosol-generating film contains multiple cellulosic agents, consisting of a cellulosic film-forming agent, a cellulosic reinforcing agent, and a cellulosic binder, the term "total cellulosic agent content" describes the combined content of the cellulosic film-forming agent, the cellulosic reinforcing agent, and the cellulosic binder in the aerosol-generating film.

[0508] Preferably, the aerosol-generating film has a total cellulosic content of 35 weight percent or greater.

[0509] The aerosol-generating film may have a total cellulosic agent content of 36 weight percent or greater, 38 weight percent or greater, or 40 weight percent or greater.

[0510] The aerosol-generating film may have a total cellulosic agent content of 52 weight percent or less, 50 weight percent or less, 48 ​​weight percent or less, 46 weight percent or less, or 44 weight percent or less.

[0511] The aerosol-generating film may have a total cellulosic agent content of 35 weight percent to 52 weight percent, 35 weight percent to 50 weight percent, 35 weight percent to 48 weight percent, 35 weight percent to 46 weight percent, or 35 weight percent to 44 weight percent.

[0512] The aerosol-generating film may have a total cellulosic agent content of 36 weight percent to 52 weight percent, 36 weight percent to 50 weight percent, 36 weight percent to 48 weight percent, 36 weight percent to 46 weight percent, or 36 weight percent to 44 weight percent.

[0513] The aerosol-generating film may have a total cellulosic agent content of 38 weight percent to 52 weight percent, 38 weight percent to 50 weight percent, 38 weight percent to 48 weight percent, 38 weight percent to 46 weight percent, or 38 weight percent to 44 weight percent.

[0514] The aerosol-generating film may have a total cellulosic agent content of 40 weight percent to 52 weight percent, 40 weight percent to 50 weight percent, 40 weight percent to 48 weight percent, 40 weight percent to 46 weight percent, or 40 weight percent to 44 weight percent.

[0515] The aerosol-generating film may include one or more cellulosic reinforcing agents.

[0516] The inclusion of one or more cellulosic reinforcing agents in an aerosol-generating film may advantageously increase the tensile strength of the aerosol-generating film. Aerosol-generating films with high tensile strength may advantageously be less likely to deteriorate or break during manufacturing and storage.

[0517] Advantageously, the aerosol-generating film may comprise one or more cellulosic reinforcing agents selected from cellulose fibers, cellulose powder, and microcrystalline cellulose (MCC).

[0518] The aerosol-generating film preferably comprises cellulose fibers, which can be particularly effective in increasing the tensile strength of the aerosol-generating film.

[0519] The aerosol-generating film may have a total cellulosic strength agent content of 5 weight percent or greater, 10 weight percent or greater, or 15 weight percent or greater.

[0520] The term "total cellulosic strength agent content" is used to describe the combined content of all cellulosic strength agents in the aerosol-generating film.

[0521] The aerosol-generating film may have a total cellulosic reinforcement content of 30 weight percent or less, 25 weight percent or less, or 20 weight percent or less.

[0522] The aerosol-generating film may have a total cellulosic reinforcement content of 5 weight percent to 30 weight percent, 5 weight percent to 25 weight percent, or 5 weight percent to 20 weight percent.

[0523] The aerosol-generating film may have a total cellulosic reinforcement content of 10 weight percent to 30 weight percent, 10 weight percent to 25 weight percent, or 10 weight percent to 20 weight percent.

[0524] The aerosol-generating film may have a total cellulosic reinforcement content of 15 weight percent to 30 weight percent, 15 weight percent to 25 weight percent, or 15 weight percent to 20 weight percent.

[0525] The aerosol-generating film may comprise cellulose fibers having a length of 0.2 millimeters or more, 0.5 millimeters or more, 0.7 millimeters or more, or 0.9 millimeters or more.

[0526] The aerosol-generating film may comprise cellulose fibers having a length of 2 millimeters or less, 1.8 millimeters or less, 1.6 millimeters or less, or 1.4 millimeters or less.

[0527] The aerosol-generating film may comprise cellulose fibers having a length of 0.2 millimeters to 2.0 millimeters, 0.2 millimeters to 1.8 millimeters, 0.2 millimeters to 1.6 millimeters, or 0.2 millimeters to 1.4 millimeters.

[0528] The aerosol-generating film may comprise cellulose fibers having a length of 0.5 millimeters to 2.0 millimeters, 0.5 millimeters to 1.8 millimeters, 0.5 millimeters to 1.6 millimeters, or 0.5 millimeters to 1.4 millimeters.

[0529] The aerosol-generating film may comprise cellulose fibers having a length of 0.5 millimeters to 2.0 millimeters, 0.5 millimeters to 1.8 millimeters, 0.5 millimeters to 1.6 millimeters, or 0.5 millimeters to 1.4 millimeters.

[0530] The aerosol-generating film may comprise cellulose fibers having a length of 0.7 millimeters to 2.0 millimeters, 0.7 millimeters to 1.8 millimeters, 0.7 millimeters to 1.6 millimeters, or 0.7 millimeters to 1.4 millimeters.

[0531] The aerosol-generating film may comprise cellulose fibers having a length of 0.9 millimeters to 2.0 millimeters, 0.9 millimeters to 1.8 millimeters, 0.9 millimeters to 1.6 millimeters, or 0.9 millimeters to 1.4 millimeters.

[0532] The aerosol-generating film may have a cellulose fiber content of 2 weight percent or more, 5 weight percent or more, 10 weight percent or more, or 15 weight percent or more.

[0533] The aerosol-generating film may have a cellulose fiber content of 30 weight percent or less, 25 weight percent or less, or 20 weight percent or less.

[0534] The aerosol-generating film may have a cellulose fiber content of 2 to 30 weight percent, 2 to 25 weight percent, or 2 to 20 weight percent.

[0535] The aerosol-generating film may have a cellulose fiber content of 5 weight percent to 30 weight percent, 5 weight percent to 25 weight percent, or 5 weight percent to 20 weight percent.

[0536] The aerosol-generating film may have a cellulose fiber content of 10 to 30 weight percent, 10 to 25 weight percent, or 10 to 20 weight percent.

[0537] The aerosol-generating film may have a cellulose fiber content of 15 to 30 weight percent, 15 to 25 weight percent, or 15 to 20 weight percent.

[0538] The aerosol-generating film may comprise microcrystalline cellulose having a D50 particle size of 5 micrometers or greater, 10 micrometers or greater, or 15 micrometers or greater.

[0539] As used herein, the term "D50 particle size" describes the median particle size of a particulate material. The D50 particle size is the particle size that divides the distribution in half, with half of the particles being larger than the D50 particle size and half of the particles being smaller than the D50 particle size. The particle size distribution can be determined by laser diffraction. For example, the particle size distribution can be determined by laser diffraction using a Malvern Mastersizer 3000 laser diffraction particle size analyzer according to the manufacturer's instructions.

[0540] The aerosol-generating film may comprise microcrystalline cellulose having a D50 particle size of 100 micrometers or less, 90 micrometers or less, or 80 micrometers or less.

[0541] The aerosol-generating film may comprise microcrystalline cellulose having a D50 particle size of 5 micrometers to 100 micrometers, 5 micrometers to 90 micrometers, or 5 micrometers to 80 micrometers.

[0542] The aerosol-generating film may comprise microcrystalline cellulose having a D50 particle size of 10 micrometers to 100 micrometers, 10 micrometers to 90 micrometers, or 10 micrometers to 80 micrometers.

[0543] The aerosol-generating film may comprise microcrystalline cellulose having a D50 particle size of 15 micrometers to 100 micrometers, 15 micrometers to 90 micrometers, or 150 micrometers to 80 micrometers.

[0544] The aerosol-generating film may have a microcrystalline cellulose content of 2 weight percent or more, 5 weight percent or more, 10 weight percent or more, or 15 weight percent or more.

[0545] The aerosol-generating film may have a microcrystalline cellulose content of 30 weight percent or less, 25 weight percent or less, or 20 weight percent or less.

[0546] The aerosol-generating film may have a microcrystalline cellulose content of from 2 weight percent to 30 weight percent, from 2 weight percent to 25 weight percent, or from 2 weight percent to 20 weight percent.

[0547] The aerosol-generating film may have a microcrystalline cellulose content of 5 weight percent to 30 weight percent, 5 weight percent to 25 weight percent, or 5 weight percent to 20 weight percent.

[0548] The aerosol-generating film may have a microcrystalline cellulose content of 10 weight percent to 30 weight percent, 10 weight percent to 25 weight percent, or 10 weight percent to 20 weight percent.

[0549] The aerosol-generating film may have a microcrystalline cellulose content of 15 weight percent to 30 weight percent, 15 weight percent to 25 weight percent, or 15 weight percent to 20 weight percent.

[0550] The aerosol-generating film may comprise a cellulose powder having a D50 particle size of 25 micrometers or greater, 30 micrometers or greater, or 35 micrometers or greater.

[0551] The aerosol-generating film may comprise a cellulose powder having a D50 particle size of 250 micrometers or less, 225 micrometers or less, or 200 micrometers or less.

[0552] The aerosol-generating film may comprise a cellulose powder having a D50 particle size of 25 micrometers to 250 micrometers, 25 micrometers to 225 micrometers, or 25 micrometers to 200 micrometers.

[0553] The aerosol-generating film may comprise a cellulose powder having a D50 particle size of 30 micrometers to 250 micrometers, 30 micrometers to 225 micrometers, or 30 micrometers to 200 micrometers.

[0554] The aerosol-generating film may comprise a cellulose powder having a D50 particle size of 35 micrometers to 250 micrometers, 35 micrometers to 225 micrometers, or 35 micrometers to 200 micrometers.

[0555] The aerosol-generating film may have a cellulose powder content of 2 weight percent or more, 5 weight percent or more, 10 weight percent or more, or 15 weight percent or more.

[0556] The aerosol-generating film may have a cellulose powder content of 30 weight percent or less, 25 weight percent or less, or 20 weight percent or less.

[0557] The aerosol-generating film may have a cellulose powder content of 2 to 30 percent by weight, 2 to 25 percent by weight, or 2 to 20 percent by weight.

[0558] The aerosol-generating film may have a cellulose powder content of 5 to 30 weight percent, 5 to 25 weight percent, or 5 to 20 weight percent.

[0559] The aerosol-generating film may have a cellulose powder content of 10 to 30 weight percent, 10 to 25 weight percent, or 10 to 20 weight percent.

[0560] The aerosol-generating film may have a cellulose powder content of 15 to 30 weight percent, 15 to 25 weight percent, or 15 to 20 weight percent.

[0561] The aerosol-generating film may comprise water.

[0562] The aerosol-generating film may have a water content of 5 weight percent or more, 10 weight percent or more, 15 weight percent or more, or 17 weight percent or more, based on the total weight of the aerosol-generating film.

[0563] The aerosol-generating film may have a water content of 35 weight percent or less, 30 weight percent or less, or 25 weight percent or less, based on the total weight of the aerosol-generating film.

[0564] The aerosol-generating film may have a water content of from 5 weight percent to 35 weight percent, from 5 weight percent to 30 weight percent, or from 5 weight percent to 25 weight percent, based on the total weight of the aerosol-generating film.

[0565] The aerosol-generating film may have a water content of from 10 weight percent to 35 weight percent, from 10 weight percent to 30 weight percent, or from 10 weight percent to 25 weight percent, based on the total weight of the aerosol-generating film.

[0566] The aerosol-generating film may have a water content of 15 to 35 weight percent, 15 to 30 weight percent, or 15 to 25 weight percent, based on the total weight of the aerosol-generating film.

[0567] The aerosol-generating film may have a water content of 17 to 35 weight percent, 17 to 30 weight percent, or 17 to 25 weight percent, based on the total weight of the aerosol-generating film.

[0568] The aerosol-generating film may include one or more non-cellulosic thickeners.

[0569] As used herein, the term "non-cellulosic thickener" is used to describe a non-cellulosic substance that, when added to an aqueous or non-aqueous liquid composition, increases the viscosity of the liquid composition without substantially altering other properties of the liquid composition. One or more non-cellulosic thickeners may increase the stability and improve the suspension of ingredients in the liquid composition. A thickener may also be referred to as a "thickener" or "rheology modifier" or "viscosifying agent."

[0570] The aerosol-generating film may include one or more non-cellulosic thickeners selected from alginate, gellan gum, guar gum, 71ectio gum, locust bean gum, pectin, starch, and xanthan gum.

[0571] The aerosol-generating film may be free of iota- or kappa-carrageenan. Aerosol-generating films that do not contain iota- or kappa-carrageenan may advantageously remain solid when heated to temperatures between 180° C. and 350° C. This may advantageously reduce or eliminate crusting in aerosol-generating articles where the susceptor is in direct contact with the substrate.

[0572] The aerosol-generating film may be agar-free. Agar-free aerosol-generating films may advantageously remain solid when heated to temperatures between 180° C. and 350° C. This may advantageously reduce or eliminate crusting in aerosol-generating articles where the susceptor is in direct contact with the substrate.

[0573] The aerosol-generating film may have a total cellulosic thickener content of 1 weight percent or greater, 2 weight percent or greater, or 3 weight percent or greater.

[0574] As used herein, the term "total non-cellulosic thickener content" is used to describe the combined content of all non-cellulosic thickeners in the aerosol-generating film.

[0575] The aerosol-generating film may have a total non-cellulosic thickener content of 10 weight percent or less, 8 weight percent or less, or 6 weight percent or less.

[0576] The aerosol-generating film may have a total non-cellulosic thickener content of from 1 weight percent to 10 weight percent, from 1 weight percent to 8 weight percent, or from 1 weight percent to 6 weight percent.

[0577] The aerosol-generating film may have a total non-cellulosic thickener content of from 2 weight percent to 10 weight percent, from 2 weight percent to 8 weight percent, or from 2 weight percent to 6 weight percent.

[0578] The aerosol-generating film may have a total non-cellulosic thickener content of 3 weight percent to 10 weight percent, 3 weight percent to 8 weight percent, or 3 weight percent to 6 weight percent.

[0579] The aerosol-generating film may include one or more flavoring agents.

[0580] Suitable flavoring agents are known in the art and include, but are not limited to, menthol.

[0581] As used herein, the term "menthol" is used to describe the compound 2-isopropyl-5-methylcyclohexanol in any of its isomeric forms.

[0582] As used herein, the term "total flavorant content" is used to describe the combined content of all flavorants in the aerosol-generating film.

[0583] The aerosol-generating film may have a total flavorant content of 0.5 weight percent or greater, 1 weight percent or greater, 2 weight percent or greater, or 3 weight percent or greater.

[0584] The aerosol-generating film may have a total flavorant content of 6 weight percent or less, 5 weight percent or less, or 4 weight percent or less.

[0585] The aerosol-generating film may have a total flavorant content of 0.5 weight percent to 6 weight percent, 0.5 weight percent to 5 weight percent, or 0.5 weight percent to 4 weight percent.

[0586] The aerosol-generating film may have a total flavorant content of from 1 weight percent to 6 weight percent, from 1 weight percent to 5 weight percent, or from 1 weight percent to 4 weight percent.

[0587] The aerosol-generating film may have a total flavorant content of 2 weight percent to 6 weight percent, 2 weight percent to 5 weight percent, or 2 weight percent to 4 weight percent.

[0588] The aerosol-generating film may have a total flavorant content of 3 weight percent to 6 weight percent, 3 weight percent to 5 weight percent, or 3 weight percent to 4 weight percent.

[0589] The aerosol-generating film may be a substantially tobacco-free aerosol-generating film.

[0590] As used herein, the term "substantially tobacco-free aerosol-generating film" describes an aerosol-generating film having a tobacco content of less than 1 weight percent. For example, the aerosol-generating film may have a tobacco content of less than 0.75 weight percent, less than 0.5 weight percent, or less than 0.25 weight percent.

[0591] The aerosol-generating film may be a tobacco-free aerosol-generating film.

[0592] As used herein, the term "tobacco-free aerosol-generating film" describes an aerosol-generating film that has zero weight percent tobacco content.

[0593] In a particularly preferred embodiment, the aerosol-generating film comprises: glycerin in an amount of 35 weight percent to 62 weight percent; Carboxymethylcellulose in an amount of 2 weight percent to 12 weight percent; hydroxypropyl methylcellulose in an amount of 14 weight percent to 40 weight percent; a total cellulosic strengthening agent content in an amount of 2 weight percent to 30 weight percent; a total carboxylic acid content in an amount of 0.5 weight percent to 8 weight percent; Nicotine in an amount of 0.5 weight percent to 10 weight percent; and water in an amount of 5 weight percent to 35 weight percent.

[0594] The wrapper surrounding the rod-shaped aerosol-generating element containing the aerosol-generating substrate can be a paper wrapper or a non-paper wrapper. Suitable paper wrappers for use in certain embodiments of the present invention are known in the art and include, but are not limited to, cigarette paper and filter plug wrap. Suitable non-paper wrappers for use in certain embodiments of the present invention are known in the art and include, but are not limited to, sheets of homogenized tobacco material. In certain preferred embodiments, the wrapper may be formed from a laminate material comprising multiple layers. Preferably, the wrapper is formed from an aluminum co-laminate sheet. The use of an aluminum-containing co-laminate sheet advantageously prevents combustion of the aerosol-generating substrate if the aerosol-generating substrate is to be ignited rather than heated in the intended manner.

[0595] In certain preferred embodiments of the present invention, an elongated susceptor element is disposed substantially longitudinally within the rod-shaped aerosol-generating element and is in thermal contact with the aerosol-generating substrate.

[0596] 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, induced eddy currents in the susceptor element cause the susceptor element to heat. When an elongated susceptor element is positioned in thermal contact with an aerosol-generating substrate, the aerosol-generating substrate is heated by the susceptor element.

[0597] When used to describe a susceptor element, the term "elongated" means that the susceptor element has a length dimension that is greater than its width dimension or its thickness dimension, for example, greater than twice its width dimension or its thickness dimension.

[0598] The susceptor elements are disposed substantially longitudinally within the rod, meaning that the length dimension of the elongated susceptor elements is disposed approximately parallel to the longitudinal axis of the rod, for example, within ±10 degrees of parallel to the longitudinal axis of the rod. In a preferred embodiment, the elongated susceptor elements may be positioned at a radially central location within the rod and extend along the longitudinal axis of the rod.

[0599] Preferably, the susceptor element extends all the way to the downstream end of the rod of the aerosol-generating article. In some embodiments, the susceptor element may extend all the way to the upstream end of the rod of the aerosol-generating article. In particularly preferred embodiments, the susceptor element has substantially the same length as the rod-shaped aerosol-generating element, extending from the upstream end of the rod to the downstream end of the rod.

[0600] The susceptor elements are preferably in the form of pins, rods, strips or blades.

[0601] The susceptor element preferably has a length of about 5 millimeters to about 15 millimeters, such as, for example, about 6 millimeters to about 12 millimeters, or about 8 millimeters to about 10 millimeters.

[0602] The ratio of the length of the susceptor element to the overall length of the aerosol-generating article substrate may be from about 0.20 to about 0.35.

[0603] Preferably, the ratio between the length of the susceptor element and the overall length of the aerosol-generating article substrate is at least about 0.22, more preferably at least about 0.24, and even more preferably at least about 0.26. The ratio between the length of the susceptor element and the overall length of the aerosol-generating article substrate is preferably less than about 0.34, more preferably less than about 0.32, and even more preferably less than about 0.30.

[0604] In some embodiments, the ratio between the length of the susceptor element and the overall length of the aerosol-generating article substrate is preferably about 0.22 to about 0.34, more preferably about 0.24 to about 0.34, and even more preferably about 0.26 to about 0.34. In other embodiments, the ratio between the length of the susceptor element and the overall length of the aerosol-generating article substrate is preferably about 0.22 to about 0.32, more preferably about 0.24 to about 0.32, and even more preferably about 0.26 to about 0.32. In further embodiments, the ratio between the length of the susceptor element and the overall length of the aerosol-generating article substrate is preferably about 0.22 to about 0.30, more preferably about 0.24 to about 0.3, and even more preferably about 0.26 to about 0.30.

[0605] In a particularly preferred embodiment, the ratio between the length of the susceptor element and the overall length of the aerosol-generating article substrate is about 0.27.

[0606] The susceptor element preferably has a width of about 1 millimeter to about 5 millimeters.

[0607] The susceptor element generally can have a thickness of about 0.01 millimeters to about 2 millimeters, for example, about 0.5 millimeters to about 2 millimeters. In some embodiments, the susceptor element preferably has a thickness of about 10 micrometers to about 500 micrometers, more preferably about 10 micrometers to about 100 micrometers.

[0608] When the susceptor element has a constant cross-section, for example a circular cross-section, it has a preferred width or diameter of about 1 millimeter to about 5 millimeters.

[0609] When the susceptor elements have the form of strips or blades, the strips or blades preferably have a rectangular shape, preferably having a width of about 2 millimeters to about 8 millimeters, more preferably about 3 millimeters to about 5 millimeters. As an example, a susceptor element in the form of a blade strip may have a width of about 4 millimeters.

[0610] When the susceptor elements are in the form of strips or blades, the strips or blades preferably have a rectangular shape and a thickness of about 0.03 millimeters to about 0.15 millimeters, more preferably about 0.05 millimeters to about 0.09 millimeters. As an example, a susceptor element in the form of a blade strip may have a thickness of about 0.07 millimeters.

[0611] In a preferred embodiment, the elongated susceptor elements are in the form of strips or blades, preferably having a rectangular shape and a thickness of about 55 micrometers to about 65 micrometers.

[0612] More preferably, the elongated susceptor elements have a thickness of about 57 micrometers to about 63 micrometers. Even more preferably, the elongated susceptor elements have a thickness of about 58 micrometers to about 62 micrometers. In a particularly preferred embodiment, the elongated susceptor elements have a thickness of about 60 micrometers.

[0613] The elongated susceptor elements preferably have a length that is the same as or shorter than the length of the aerosol-generating substrate.The elongated susceptor elements preferably have the same length as the aerosol-generating substrate.

[0614] The susceptor element may 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.

[0615] Preferred susceptor elements may include or consist of a ferromagnetic material, such as, for example, a ferromagnetic alloy, ferritic iron, or ferromagnetic steel or stainless steel. Suitable susceptor elements may be or include aluminum. Preferred susceptor elements may be formed from 400 series stainless steel, such as grade 410, grade 420, or grade 430 stainless steel. Different materials dissipate different amounts of energy when placed in electromagnetic fields of similar frequency and field strength.

[0616] Thus, any of the susceptor element parameters, such as type of material, length, width, and thickness, can be varied to provide a desired power distribution within a known electromagnetic field. Preferred susceptor elements may be heated to temperatures in excess of 250 degrees Celsius.

[0617] Suitable susceptor elements may include a non-metallic core having a metal layer, such as a metal band formed on the surface of the ceramic core. The susceptor element may have a protective outer layer, such as a protective ceramic or glass layer, encapsulating the susceptor element. The susceptor element may include a protective coating formed of glass, ceramic, or an inert metal formed over a core of susceptor element material.

[0618] The susceptor element is disposed in thermal contact with the aerosol-generating substrate, such that as the temperature of the susceptor element increases, the aerosol-generating substrate is heated and an aerosol is formed. Preferably, the susceptor element is disposed in direct physical contact with the aerosol-generating substrate, for example, within the aerosol-generating substrate.

[0619] The susceptor element may be a multi-material susceptor element and may comprise a first susceptor element material and a second susceptor element material. The first susceptor element material is disposed in close physical contact with the second susceptor element material. The second susceptor element material preferably has a Curie temperature below 500 degrees Celsius. The first susceptor element material is preferably primarily used to heat the susceptor element when the susceptor element is placed in a fluctuating electromagnetic field. Any suitable material may be used. For example, the first susceptor element material may be aluminum or an iron-based material such as stainless steel. The second susceptor element material is preferably primarily used to indicate when the susceptor element reaches a specific temperature, which is the Curie temperature of the second susceptor element material. The Curie temperature of the second susceptor element material can be used to regulate the temperature of the entire susceptor element during operation. Therefore, the Curie temperature of the second susceptor element material should be below the ignition point of the aerosol-generating substrate. Suitable materials for the second susceptor element material may include nickel and certain nickel alloys.

[0620] The heating of the aerosol-generating substrate and the temperature control of the heating can be separated by providing a susceptor element having at least first and second susceptor element materials with a second susceptor element material having a Curie temperature and a first susceptor element material having no Curie temperature, or by providing first and second susceptor element materials having different first and second Curie temperatures. The first susceptor element material is preferably a magnetic material having a Curie temperature greater than 500°C. From the standpoint of heating efficiency, it is desirable that the Curie temperature of the first susceptor element material exceed any maximum temperature to which the susceptor element can be heated. The second Curie temperature may be selected to be preferably lower than 400°C, preferably lower than 380°C, or even lower than 360°C. The second susceptor element material is preferably a magnetic material selected to have a second Curie temperature substantially equal to the desired maximum heating temperature. That is, the second Curie temperature is preferably approximately the same as the temperature to which the susceptor element must be heated to generate an aerosol from the aerosol-generating substrate. The second Curie temperature may be, for example, within the range of 200° C. to 400° C., or within the range of 250° C. to 360° C. The second Curie temperature of the second susceptor element material may be selected, for example, such that the overall average temperature of the aerosol-generating substrate does not exceed 240° C. when heated by a susceptor element having a temperature equal to the second Curie temperature.

[0621] The aerosol-generating article of the present invention can further include an upstream element located upstream of and adjacent to the aerosol-generating substrate, the upstream section including at least one upstream element. The upstream element advantageously prevents direct physical contact with the upstream end of the aerosol-generating substrate. In particular, if the aerosol-generating substrate includes a susceptor element, the upstream element can 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. This in turn 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 can be advantageous, for example, when the substrate contains particulate plant material.

[0622] The upstream element may also provide an improved appearance to the upstream end of the aerosol-generating article. Additionally, if desired, the upstream element may be used to provide information about the aerosol-generating article, such as the brand, flavor, content, or details of the aerosol-generating device in which the article is intended to be used.

[0623] The upstream element may be a porous plug element. Preferably, the porous plug element does not alter the withdrawal resistance of the aerosol-generating article. Preferably, the upstream element has a porosity of at least about 50 percent along the longitudinal axis of the aerosol-generating article. More preferably, the upstream element has a porosity of between about 50 percent and about 90 percent along the longitudinal axis. The porosity of the upstream element along the longitudinal axis is defined 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 location of the upstream element.

[0624] The upstream element may be made of a porous material or may comprise a plurality of openings, which may be achieved, for example, by laser drilling, and the plurality of openings are preferably homogeneously distributed across the cross section of the upstream element.

[0625] The porosity or permeability of the upstream element may be advantageously varied to provide a desired overall resistance to withdrawal of the aerosol-generating article.

[0626] Preferably, the RTD of the upstream element is at least about 5 millimeters of H2O. More preferably, the RTD of the upstream element is at least about 10 millimeters of H2O. Even more preferably, the RTD of the upstream element is at least about 15 millimeters of H2O. In a particularly preferred embodiment, the RTD of the upstream element is at least about 20 millimeters of H2O.

[0627] The RTD of the upstream element is preferably about 80 millimeters H2O or less. More preferably, the RTD of the upstream element is about 60 millimeters H2O or less. Even more preferably, the RTD of the upstream element is about 40 millimeters H2O or less.

[0628] In some embodiments, the RTD of the upstream element is between about 5 millimeters of HO and about 80 millimeters of HO, preferably between about 10 millimeters of HO and about 80 millimeters of HO, more preferably between about 15 millimeters of HO and about 80 millimeters of HO, and even more preferably between about 20 millimeters of HO and about 80 millimeters of HO. In other embodiments, the RTD of the upstream element is between about 5 millimeters of HO and about 70 millimeters of HO, preferably between about 10 millimeters of HO and about 70 millimeters of HO, more preferably between about 15 millimeters of HO and about 70 millimeters of HO, and even more preferably between about 20 millimeters of HO and about 70 millimeters of HO. In other embodiments, the RTD of the upstream element is between about 5 millimeters of HO and about 60 millimeters of HO, preferably between about 10 millimeters of HO and about 60 millimeters of HO, more preferably between about 15 millimeters of HO and about 60 millimeters of HO, and even more preferably between about 20 millimeters of HO and about 60 millimeters of HO. In a further embodiment, the RTD of the upstream element is from about 5 millimeters HO to about 40 millimeters HO, preferably from about 10 millimeters HO to about 40 millimeters HO, more preferably from about 15 millimeters HO to about 40 millimeters HO, and even more preferably from about 20 millimeters HO to about 40 millimeters HO.

[0629] In alternative embodiments, the upstream element may be formed from a material that is impermeable to air. In such embodiments, the aerosol-generating article may be configured to allow air to flow into the rod-shaped aerosol-generating element via suitable venting means provided in the wrapper.

[0630] The upstream element can be made of any material suitable for use in an aerosol-generating article. The upstream element may be made of the same material as that used in one of the other components of the aerosol-generating article, such as the mouthpiece, cooling element, or support element. Suitable materials for the upstream element include filter material, ceramic, polymeric material, cellulose acetate, cardboard, zeolite, or an aerosol-generating substrate. The upstream element is preferably formed from a plug of cellulose acetate.

[0631] The upstream element is preferably formed from a heat resistant material, for example, a material that can withstand temperatures up to 350 degrees Celsius, to ensure that the upstream element is not adversely affected by the heating means for heating the aerosol-generating substrate.

[0632] The upstream element preferably has a diameter approximately equal to the diameter of the aerosol-generating article.

[0633] Preferably, the upstream element has a length of about 1 millimeter to about 10 millimeters, more preferably about 3 millimeters to about 8 millimeters, and even more preferably about 4 millimeters to about 6 millimeters. In a particularly preferred embodiment, the upstream element has a length of about 5 millimeters. The length of the upstream element can be advantageously varied to provide a desired overall length for the aerosol-generating article. For example, if it is desired to reduce the length of one of the other components of the aerosol-generating article, the length of the upstream element can be increased to maintain the same overall length for the article.

[0634] The upstream element preferably has a substantially homogeneous structure. For example, the upstream element may be substantially homogeneous in texture and appearance. The upstream element may, for example, have a continuous, regular surface over its entire cross section. The upstream element may, for example, not have any discernible symmetry.

[0635] The upstream element is preferably surrounded by a wrapper that is preferably a stiff plug wrap, such as a plug wrap having a basis weight of at least about 80 grams per square meter (gsm), or at least about 100 gsm, or at least about 110 gsm, to provide structural rigidity to the upstream element.

[0636] Aerosol-generating articles according to the present invention may have a length of from about 35 millimeters to about 100 millimeters.

[0637] Preferably, the overall length of an aerosol-generating article according to the present invention is at least about 38 millimeters. More preferably, the overall length of an aerosol-generating article according to the present invention is at least about 40 millimeters. Even more preferably, the overall length of an aerosol-generating article according to the present invention is at least about 42 millimeters.

[0638] Preferably, the overall length of an aerosol-generating article according to the present invention is 70 mm or less, more preferably 60 mm or less, and even more preferably 50 mm or less.

[0639] In some embodiments, the total length of the aerosol-generating article is preferably between about 38 millimeters and about 70 millimeters, more preferably between about 40 millimeters and about 70 millimeters, and even more preferably between about 42 millimeters and about 70 millimeters. In other embodiments, the total length of the aerosol-generating article is preferably between about 38 millimeters and about 60 millimeters, more preferably between about 40 millimeters and about 60 millimeters, and even more preferably between about 42 millimeters and about 60 millimeters. In further embodiments, the total length of the aerosol-generating article is preferably between about 38 millimeters and about 50 millimeters, more preferably between about 40 millimeters and about 50 millimeters, and even more preferably between about 42 millimeters and about 50 millimeters. In an exemplary embodiment, the total length of the aerosol-generating article is about 45 millimeters.

[0640] Preferably, 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.

[0641] 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.

[0642] In some embodiments, the aerosol-generating article has an outer diameter of about 5 mm to about 12 mm, preferably about 6 mm to about 12 mm, and more preferably about 7 mm to about 12 mm. In other embodiments, the aerosol-generating article has an outer diameter of about 5 mm to about 10 mm, preferably about 6 mm to about 10 mm, and more preferably about 7 mm to about 10 mm. In further embodiments, the aerosol-generating article has an outer diameter of about 5 mm to about 8 mm, preferably about 6 mm to about 8 mm, and more preferably about 7 mm to about 8 mm.

[0643] In certain preferred embodiments of the present invention, the diameter of the aerosol-generating article at the mouth end (D ME ) is the diameter of the aerosol-generating article at its distal end (D DE ) is (preferably) greater than the ratio between the diameter of the aerosol-generating article at the oral end and the diameter of the aerosol-generating article at the distal end (D ME / D DE ) is (preferably) at least about 1.005.

[0644] Preferably, the ratio between the diameter of the aerosol-generating article at the oral end and the diameter of the aerosol-generating article at the distal end (D ME / D DE ) is (preferably) at least about 1.01. More preferably, the ratio between the diameter of the aerosol-generating article at the oral end and the diameter of the aerosol-generating article at the distal end (D ME / D DE ) is at least about 1.02. Even more preferably, the ratio between the diameter of the aerosol-generating article at the oral end and the diameter of the aerosol-generating article at the distal end (D ME / D DE ) is at least about 1.05.

[0645] The ratio between the diameter of the aerosol-generating article at the oral end and the diameter of the aerosol-generating article at the distal end (D ME / D DEPreferably, the ratio between the diameter of the aerosol-generating article at the oral end and the diameter of the aerosol-generating article at the distal end (D ME / D DE ) is about 1.25 or less. Even more preferably, the ratio between the diameter of the aerosol-generating article at the oral end and the diameter of the aerosol-generating article at the distal end (D ME / D DE ) is about 1.20 or less. In particularly preferred embodiments, the ratio between the diameter of the aerosol-generating article at the oral end and the diameter of the aerosol-generating article at the distal end (D ME / D DE ) is less than or equal to 1.15 or 1.10.

[0646] In some preferred embodiments, the ratio between the diameter of the aerosol-generating article at the oral end and the diameter of the aerosol-generating article at the distal end (D ME / D DE ) is about 1.01 to 1.30, more preferably 1.02 to 1.30, and even more preferably 1.05 to 1.30.

[0647] In other embodiments, the ratio between the diameter of the aerosol-generating article at the oral end and the diameter of the aerosol-generating article at the distal end (D ME / D DE ) is about 1.01 to 1.25, more preferably 1.02 to 1.25, and even more preferably 1.05 to 1.25. In a further embodiment, the ratio between the diameter of the aerosol-generating article at the oral end and the diameter of the aerosol-generating article at the distal end (D ME / D DE ) is about 1.01 to 1.20, more preferably 1.02 to 1.20, and even more preferably 1.05 to 1.20. In still further embodiments, the ratio between the diameter of the aerosol-generating article at the oral end and the diameter of the aerosol-generating article at the distal end (D ME / D DE ) is about 1.01 to 1.15, more preferably 1.02 to 1.15, and even more preferably 1.05 to 1.15.

[0648] By way of example, the outer diameter of the article may be substantially constant over a distal portion of the aerosol-generating article that extends at least about 5 millimeters or at least about 10 millimeters from the distal end. Alternatively, the outer diameter of the article may taper over a distal portion of the article that extends at least about 5 millimeters or at least about 10 millimeters from the distal end.

[0649] In certain preferred embodiments of the present invention, as described above, the elements of the aerosol-generating article are arranged so that the center of mass of the aerosol-generating article is at least about 60 percent along the length of the aerosol-generating article from the downstream end, more preferably the elements of the aerosol-generating article are arranged so that the center of mass of the aerosol-generating article is at least about 62 percent along the length of the aerosol-generating article from the downstream end, and more preferably at least about 65 percent along the length of the aerosol-generating article from the downstream end.

[0650] The center of mass is preferably no more than about 70 percent along the length of the aerosol-generating article from the downstream end.

[0651] Providing an arrangement of elements that provides a center of mass closer to the upstream end than the downstream end results in an aerosol-generating article with a weight imbalance, with the upstream end being heavier. This weight imbalance can advantageously provide tactile feedback to the consumer, allowing them to distinguish between the upstream and downstream ends and insert the correct end into the aerosol generating device. This can be particularly beneficial when the upstream elements are provided such that the upstream and downstream ends of the aerosol-generating article visually resemble each other.

[0652] In embodiments of aerosol-generating articles according to the invention, both the aerosol cooling element and the support element are present and are preferably wrapped together in a combined wrapper that surrounds the aerosol cooling element and the support element but does not surround anything further downstream, such as a mouthpiece filter segment.

[0653] In these embodiments, the aerosol cooling element and support element are combined before being surrounded by the combined wrapper, and then further combined with the mouthpiece segment.

[0654] From a manufacturing standpoint, this is advantageous in that it allows shorter aerosol-generating articles to be constructed.

[0655] In general, it can be difficult to handle individual elements with lengths smaller than their diameters. For example, for a 7-millimeter diameter element, a length of about 7 millimeters represents a threshold that is desirable to remain constant. However, a 10-millimeter aerosol-cooling element can be combined with a pair of 7-millimeter support elements on each side (and potentially with other elements, such as rod-shaped aerosol-generating elements) to provide a 24-millimeter hollow segment, which can then be cut into two intermediate 12-millimeter hollow sections.

[0656] In a particularly preferred embodiment, the other components of the aerosol-generating article are individually surrounded by their own wrappers. In other words, the upstream element, the rod-shaped aerosol-generating element, the support element, and the aerosol-cooling element are all individually wrapped. The support element and the aerosol-cooling element are combined to form a hollow section. This is achieved by wrapping the support element and the aerosol-cooling element in a combined wrapper. The upstream element, the rod-shaped aerosol-generating element, and the hollow section are then combined together with an outer wrapper. They are then combined with a mouthpiece section with its own wrapper using tipping paper.

[0657] Preferably, at least one of the components of the aerosol-generating article is packaged in a hydrophobic wrapper.

[0658] The term "hydrophobicity" refers to a surface that exhibits water-repellent properties. One useful way to determine this is to measure the water contact angle. The "water contact angle" is the angle traditionally measured through a liquid where the liquid / vapor interface meets a solid surface. The water contact angle quantifies the wettability of a solid surface by a liquid via Young's equation. Hydrophobicity or water contact angle can be determined by utilizing the TAPPI T558 test method, with results expressed as interfacial contact angle, reported in degrees, and can range from approximately zero to approximately 180 degrees.

[0659] In a preferred embodiment, the hydrophobic wrapper is a wrapper that includes a paper layer that has a water contact angle of about 30 degrees or greater, preferably about 35 degrees or greater, or about 40 degrees or greater, or about 45 degrees or greater.

[0660] By way of example, the paper layer may comprise PVOH (polyvinyl alcohol) or silicone. The PVOH may be applied to the paper layer as a surface coating, or the paper layer may include a surface treatment that includes PVOH or silicone.

[0661] In a particularly preferred embodiment, an aerosol-generating article according to the invention comprises, in a linear continuous arrangement, an upstream element, a rod-shaped aerosol-generating element located immediately downstream of the upstream element, a support element located immediately downstream of the rod-shaped aerosol-generating element, an aerosol cooling element located immediately downstream of the support element, a mouthpiece section including a single mouthpiece filter segment located immediately downstream of the aerosol cooling element, and an outer wrapper surrounding the upstream element, the rod of aerosol-generating substrate, the support element, the aerosol cooling element, and the mouthpiece filter segment.

[0662] More specifically, the rod-shaped aerosol-generating element may abut the upstream element. The support element may abut the rod-shaped aerosol-generating element. The aerosol-cooling element may abut the support element. The mouthpiece filter segment may abut the aerosol-cooling element.

[0663] The aerosol-generating article has a substantially cylindrical shape and an outer diameter of about 7.25 millimeters.

[0664] The upstream element has a length of about 5 mm, the rod of the aerosol-generating article has a length of about 12 mm, the support element has a length of about 8 mm, the aerosol cooling element has a length of about 8 mm, and the mouthpiece filter segment has a length of about 12 mm, so that the total length of the aerosol-generating article is about 45 mm.

[0665] The upstream element is in the form of a plug of cellulose acetate encased in a stiff plug wrap.

[0666] The aerosol-generating article comprises an elongated susceptor element disposed substantially longitudinally within the rod-shaped aerosol-generating element and in thermal contact with the aerosol-generating substrate, the susceptor element being in the form of a strip or blade and having a length substantially equal to the length of the rod-shaped aerosol-generating element and a thickness of about 60 micrometers.

[0667] The support element is in the form of a hollow cellulose acetate tube and has an inner diameter of about 1.9 millimeters, so that the peripheral wall thickness of the support element is about 2.675 millimeters.

[0668] The aerosol cooling element is in the form of a finer hollow cellulose acetate tube and has an inner diameter of about 3.25 millimeters, so the peripheral wall thickness of the aerosol cooling element is about 2 millimeters.

[0669] The mouthpiece is in the form of a low density cellulose acetate filter segment.

[0670] The rod-shaped aerosol-generating element comprises an aerosol-generating substrate comprising the aerosol-generating film described above.

[0671] The invention will now be further described with reference to the accompanying drawings.

[0672] 1 comprises a rod 12 of aerosol-generating substrate 12 and a downstream section 14 of aerosol-generating substrate located downstream of rod 12. Aerosol-generating article 10 thus extends from an upstream or distal end 16, which is substantially coincident with the upstream end of rod 12, to a downstream or mouth end 18, which is coincident with the downstream end of downstream section 14.

[0673] The aerosol-generating article 10 has an overall length of about 45 millimeters.

[0674] The aerosol-generating substrate rod 12 comprises an aerosol-generating film as described herein.

[0675] The downstream section 14 comprises a hollow tubular element 20 disposed immediately downstream of the rod 12 of the aerosol-generating substrate, the hollow tubular element 20 being longitudinally aligned with the rod 12. In the embodiment of Figure 1, the upstream end of the hollow tubular element 20 abuts the downstream end of the rod 12 of the aerosol-generating substrate.

[0676] The hollow tubular element 20 defines the hollow section 15 of the aerosol-generating article 10. The hollow tubular element does not contribute substantially to the overall RTD of the aerosol-generating article. More specifically, the RTD of the downstream section is about 0 mmH2O.

[0677] The hollow tubular element 20 is provided in the form of a hollow cylindrical tube made of cellulose acetate or stiff paper, such as paper having a grammage of at least about 90 g / sqm. The hollow tubular element 20 defines an interior cavity 22 that extends from the upstream end 24 of the hollow tubular element all the way to the downstream end 26 of the hollow tubular element 20. The interior cavity 22 is substantially empty, thus permitting substantially unrestricted airflow along the interior cavity 22. The hollow tubular element 20 does not substantially contribute to the overall RTD of the aerosol-generating article 10.

[0678] The hollow tubular element 20 has a length of about 33 millimeters and an outer diameter (D) of about 7.3 millimeters. E ), and an inner diameter (D I ) The thickness of the peripheral wall of the hollow tubular element 20 is therefore about 0.1 millimeters.

[0679] The aerosol-generating article 10 includes a ventilation zone 30 located along the hollow tubular element 20. More specifically, the ventilation zone 30 is located approximately 18 millimeters from the downstream end 26 of the hollow tubular element 20. That is, in the embodiment of Figure 1, the ventilation zone 30 is effectively located 18 millimeters from the mouth end 18 of the aerosol-generating article 10. The ventilation level of the aerosol-generating article 10 is approximately 40 percent.

[0680] In the embodiment of FIG. 1, the aerosol-generating article does not include any additional components upstream of the rod of aerosol-generating substrate 12 or downstream of hollow tubular element 20 .

[0681] The aerosol-generating article 100 shown in Figure 2 differs from the aerosol-generating article 10 described above only in that it is provided with an upstream section 40 located upstream of the aerosol-generating element. Accordingly, the aerosol-generating article 100 will be described only insofar as it differs from the aerosol-generating article 10.

[0682] Atop the aerosol-generating substrate rod 12 and downstream section 14 located downstream of the rod 12, the aerosol-generating article 100 includes an upstream section 40 located upstream of the rod 12. The aerosol-generating article 10 thus extends from a distal end 16 that is substantially coincident with the upstream end of the upstream section 40 to a mouth or downstream end 18 that is substantially coincident with the downstream end of the downstream section 14.

[0683] The upstream section 40 includes an upstream element 42 located immediately upstream of the aerosol-generating substrate rod 12, with the upstream element 42 being longitudinally aligned with the rod 12. In the embodiment of FIG. 2, the downstream end of the upstream element 42 abuts the upstream end of the aerosol-generating substrate rod 12. The upstream element 42 is provided in the form of a cylindrical plug of cellulose acetate surrounded by a hard wrapper. The upstream element 42 has a length of approximately 5 millimeters. The RTD of the upstream element 42 is approximately 30 millimeters HO.

[0684] The aerosol-generating article 110 shown in Figure 3 comprises a rod of aerosol-generating substrate 12 and a downstream section 14 located downstream of the rod of aerosol-generating substrate 12. The aerosol-generating article 110 further comprises an upstream section 40 located upstream of the rod of aerosol-generating substrate 12. The aerosol-generating article 110 may therefore extend from an upstream or distal end 16 to a downstream or oral end 18.

[0685] The aerosol-generating article has a total length of about 45 millimeters.

[0686] The downstream section 14 includes a support element 46 located immediately downstream from the rod 12 of the aerosol-generating substrate, the support element 46 being longitudinally aligned with the rod 12. In the embodiment of Figure 3, an upstream end 48 of the support element 46 abuts the downstream end of the rod 12 of the aerosol-generating substrate. The downstream section 14 also includes an aerosol-cooling element 50 located immediately downstream from the support element 46, the aerosol-cooling element 50 being longitudinally aligned with the rod 12 and the support element 46. In the embodiment of Figure 4, an upstream end 52 of the aerosol-cooling element 50 abuts the downstream end 54 of the support element 46.

[0687] As will become apparent from the description below, the support element 46 and the aerosol cooling element 50 together define the intermediate hollow section 15 of the aerosol-generating article 110. As a whole, the intermediate hollow section 15 does not contribute substantially to the overall RTD of the aerosol-generating article. The RTD of the intermediate hollow section 15 as a whole is substantially 0 millimeters HO.

[0688] The support element 46 includes a first hollow tubular element 56. The first hollow tubular element 56 is provided in the form of a hollow cylindrical tube made of cellulose acetate. The first hollow tubular element 56 defines an interior cavity 58 extending entirely from the upstream end 48 of the first hollow tubular element to the downstream end 54 of the first hollow tubular element 56. The interior cavity 58 is substantially empty, such that substantially unrestricted airflow is possible along the interior cavity 58. The first hollow tubular element 56, and consequently the support element 46, does not substantially contribute to the overall RTD of the aerosol-generating article 110. More specifically, the RTD of the first hollow tubular element 56 (which is substantially the RTD of the support element 46) is substantially 0 millimeters HO.

[0689] The first hollow tubular element 56 has a length of about 8 millimeters, an outer diameter of about 7.25 millimeters, and an inner diameter (D FTS ) Therefore, the peripheral wall thickness of the first hollow tubular element 56 is about 2.67 millimeters.

[0690] The aerosol cooling element 50 includes a second hollow tubular element 60. The second hollow tubular element 60 is provided in the form of a hollow cylindrical tube made of cellulose acetate. The second hollow tubular element 60 defines an interior cavity 62 extending entirely from the upstream end 52 of the second hollow tubular element to the downstream end 64 of the second hollow tubular element 60. The interior cavity 62 is substantially empty, such that substantially unrestricted airflow is possible along the interior cavity 62. The second hollow tubular element 60, and consequently the aerosol cooling element 50, does not substantially contribute to the overall RTD of the aerosol-generating article 110. More specifically, the RTD of the second hollow tubular element 60 (which is essentially the RTD of the aerosol cooling element 124) is substantially 0 millimeters HO.

[0691] The second hollow tubular element 60 has a length of about 8 millimeters, an outer diameter of about 7.25 millimeters, and an inner diameter (D STS) The thickness of the peripheral wall of the second hollow tubular element 60 is therefore about 2 millimeters. FTS ) and the inner diameter (D STS ) is about 0.75.

[0692] The aerosol-generating article 110 includes a ventilation zone 30 provided along the second hollow tubular element 60. More specifically, the ventilation zone is provided approximately 2 millimeters from the upstream end of the second hollow tubular element 60. The aerosol-generating article 110 has a ventilation level of approximately 25 percent.

[0693] In the embodiment of Figure 3, the downstream section 14 further includes a mouthpiece section 68 located downstream of the intermediate hollow section 15. The mouthpiece section 68 is provided in the form of a single mouthpiece filter segment 66, a cylindrical plug of low-density cellulose acetate. More particularly, the mouthpiece filter segment 66 is positioned immediately downstream of the aerosol cooling element 50. As shown in the drawing of Figure 3, the upstream end of the mouthpiece filter segment 66 abuts the downstream end 64 of the aerosol cooling element 50. The mouthpiece filter segment 66 extends all the way to the oral end 18 of the aerosol-generating article 110.

[0694] Both mouthpiece section 68 and mouthpiece filter segment 66 have a length of approximately 12 millimeters and an outer diameter of approximately 7.25 millimeters. The RTD of mouthpiece section 68 (and mouthpiece filter segment 66) is approximately 12 millimeters HO. The ratio of the length of mouthpiece section 68 to the length of intermediate hollow section 15 is approximately 0.75. The ratio of the length of mouthpiece filter segment 66 to the length of intermediate hollow section 15 is approximately 0.75.

[0695] The rod 12 includes an aerosol-generating substrate of one of the types described above.

[0696] The aerosol-generating substrate rod 12 has an outer diameter of about 7.25 millimeters and a length of about 12 millimeters.

[0697] The aerosol-generating article 110 further comprises an elongated susceptor element 44 within the rod 12 of the aerosol-generating substrate. More specifically, the susceptor element 44 is substantially longitudinally disposed within the aerosol-generating substrate, generally parallel to the longitudinal axis of the rod 12. As shown in the drawing in Figure 3, the susceptor element 44 is positioned at a radially central location within the rod and effectively extends along the longitudinal axis of the rod 12.

[0698] The susceptor element 44 extends completely from the upstream end to the downstream end of the rod 12. In practice, the susceptor element 44 has substantially the same length as the rod 12 of the aerosol-generating substrate.

[0699] In the embodiment of Figure 3, the susceptor element 44 is provided in the form of a strip, having a length of about 12 millimeters, a thickness of about 60 micrometers, and a width of about 4 millimeters. The upstream section 40 includes an upstream element 42 located immediately upstream of the aerosol-generating substrate rod 12, with the upstream element 42 being longitudinally aligned with the rod 12. In the embodiment of Figure 3, the downstream end of the upstream element 42 abuts the upstream end of the aerosol-generating substrate rod 12. This advantageously prevents the susceptor element 44 from becoming dislodged. This further ensures that consumers cannot accidentally come into contact with the heated susceptor element 44 after use.

[0700] The upstream element 42 is provided in the form of a cylindrical plug of cellulose acetate surrounded by a hard wrapper. The upstream element 42 has a length of approximately 5 millimeters. The RTD of the upstream element 42 is approximately 30 millimeters HO.

[0701] 4 differs from the aerosol-generating article 110 described above only in that the mouthpiece section 68 is provided with an oral-end cavity 70. The upstream end 74 of the third hollow tubular element 72 abuts the mouthpiece filter segment 66 at the downstream end thereof. The third hollow tubular element 72 defines the oral-end cavity 70 at the oral end 18 of the aerosol-generating article 120.

[0702] The third hollow tubular element 72 has a length of about 7 millimeters, an outer diameter of about 7.25 millimeters, and an inner diameter (D STS ) Therefore, the thickness of the peripheral wall of the second hollow tubular element 72 is about 2 millimeters.

[0703] The mouthpiece section 68 has a length of approximately 12 millimeters and an outer diameter of approximately 7.25 millimeters. The RTD of the mouthpiece section 68 is approximately 5 millimeters HO. The ratio of the length of the mouthpiece section 68 to the length of the intermediate hollow section 15 is 0.75.

[0704] The aerosol-generating article 130 of Figure 5 is identical to the aerosol-generating article 110 of Figure 3, except that in the downstream section 14, the mouthpiece section 68 is replaced with a third hollow tubular element 72. As in the aerosol-generating articles 10 and 110 of Figures 1 and 2, the hollow section 15 extends entirely from the downstream end of the aerosol-generating substrate 12 to the oral end 18 of the aerosol-generating article 130. In the aerosol-generating article 130 shown in Figure 5, the third hollow tubular element 72 abuts the second hollow tubular element 50 at the downstream end 64 of the second hollow tubular element 50 in the downstream section 14. The third hollow tubular element 72 provides the oral end cavity 70 at the oral end 18 of the aerosol-generating article 130. The third hollow tubular element 72 provides a second aerosol-cooling element 76 immediately downstream of the first aerosol-cooling element 60.

[0705] The third hollow tubular element 72 has a length of about 12 millimeters, an outer diameter of about 7.25 millimeters, and an inner diameter (D STS ) The thickness of the peripheral wall of the third hollow tubular element 72 is therefore about 2 millimeters.

Claims

1. 1. An aerosol-generating article for generating an inhalable aerosol upon heating, the aerosol-generating article extending from an oral end to a distal end; a rod-shaped aerosol-generating element comprising an aerosol-generating substrate, the aerosol-generating substrate comprising an aerosol-generating film; a downstream section located downstream of the aerosol-generating element, the downstream section extending from the downstream end of the aerosol-generating element to the mouth end of the aerosol-generating article; the downstream section includes a hollow section defining a longitudinal cavity providing an unrestricted flow channel; The RTD of the downstream section is 25 mmH 2 is less than O, 1. An aerosol-generating article, wherein the aerosol-generating film comprises one or more cellulosic film-forming agents and one or more aerosol formers, the aerosol-generating film having a total aerosol-former content of 46 weight percent or greater.

2. 2. The aerosol-generating article of claim 1, wherein the hollow section includes a first hollow tubular element defining the longitudinal cavity that provides the unrestricted flow channel.

3. 3. The aerosol-generating article of claim 2, wherein the hollow section further comprises a second hollow tubular element, the first and second hollow tubular elements defining the longitudinal cavity that provides the unrestricted flow channel.

4. 4. An aerosol-generating article according to any one of claims 1 to 3, wherein the hollow section has a length of at least about 25 millimeters and extends all the way to the mouth end of the aerosol-generating article.

5. 5. The aerosol-generating article of claim 1, wherein the downstream section further comprises a mouthpiece section including at least one mouthpiece filter segment formed from a fibrous filtering material.

6. The RTD of the downstream section is about 20 mmH 2 Less than 0, preferably about 15 mmH 2 Less than 0, preferably about 10 mmH 2 Less than 0, preferably about 5 mmH 2 Less than 0, preferably about 0 mmH 2 The aerosol-generating article according to any one of claims 1 to 5, wherein

7. 7. The aerosol-generating article of claim 1, wherein the aerosol-generating film comprises one or more carboxylic acids selected from acetic acid, adipic acid, benzoic acid, citric acid, fumaric acid, maleic acid, malic acid, myristic acid, oxalic acid, salicylic acid, stearic acid, succinic acid, undecanoic acid, and C1 to C10 saturated alkyl monocarboxylic acids.

8. 8. The aerosol-generating article according to claim 1, wherein the aerosol-generating film comprises fumaric acid.

9. 9. The aerosol-generating article according to claim 1, wherein the aerosol-generating film further comprises one or more carboxylic acids selected from lactic acid and levulinic acid.

10. 10. The aerosol-generating article according to any one of claims 1 to 9, wherein the aerosol-generating film has a total carboxylic acid content of from 1 weight percent to 6 weight percent.

11. 11. The aerosol-generating article according to claim 1, wherein the one or more aerosol formers comprise glycerin.

12. 12. The aerosol-generating article of any one of claims 1 to 11, wherein the one or more cellulosic film-forming agents are selected from carboxymethyl cellulose and hydroxypropyl methyl cellulose.

13. 13. The aerosol-generating article according to any one of claims 1 to 12, wherein the aerosol-generating film has a hydroxypropyl methylcellulose content of from 14 to 40 percent by weight.

14. 14. The aerosol-generating article according to any one of claims 1 to 13, wherein the aerosol-generating film comprises one or more cellulose-based reinforcing agents selected from cellulose fibers, microcrystalline cellulose, and cellulose powder.

15. 15. The aerosol-generating article according to any one of claims 1 to 14, wherein the aerosol-generating film has a total aerosol-former content of from 46 percent to 62 percent by weight.

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