Aerosol-generating article with a plug segment adjacent to an aerosol-generating element - Patent Application 20070229633

Abstract

An aerosol-generating article (1) for generating an inhalable aerosol upon heating is provided. The aerosol-generating article comprises a first plug segment (2), a second plug segment (6), an aerosol-generating element (4), and a wrapper (8). The second plug segment is permeable. The aerosol-generating element is positioned immediately between the first plug segment and the second plug segment. The second plug segment is located downstream from the aerosol-generating element. The wrapper surrounds the first plug segment, the aerosol-generating element, and the second plug segment. A portion (12) of the wrapper surrounding the aerosol-generating element is air permeable such that the wrapper establishes fluid communication between the exterior of the aerosol-generating article and the aerosol-generating element.

Description

[Technical field]

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

[0002] Aerosol-generating articles in which an aerosol-generating substrate, such as a tobacco-containing substrate, is heated rather than burned, are known in the art.Typically, in such heated smoking articles, 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 the 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] 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 the aerosol is 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, which includes an internal heater blade adapted to be inserted into the aerosol-generating substrate. As an alternative, WO2015 / 176898 proposes an inductively heated aerosol-generating article, which includes an aerosol-generating substrate and a susceptor disposed within the aerosol-generating substrate. A further alternative is described in WO2020 / 115151, which discloses an aerosol-generating article used in combination with an external heating system comprising one or more heating elements disposed around the outer surface of the aerosol-generating article. For example, the external heating element may be provided in the form of a flexible heating foil on a dielectric substrate, such as polyimide.

[0004] Aerosol-generating articles in which an aerosol-forming (or aerosol-generating) substrate, such as a tobacco-containing substrate, is heated rather than combusted, present a number of challenges not found in conventional smoking articles. Current articles are designed to be used in devices that heat the aerosol-forming substrate externally and have heaters configured to draw air primarily axially or longitudinally through the aerosol-forming substrate. However, the inventors have found that when using the article with an externally heated device or aerosol-generating device, it can be very beneficial to allow flexibility in the combination of axial and radial air entering the article, which can result in improved aerosol delivery to the end user. In particular, in the context of an external heater that surrounds at least a portion of the aerosol-generating substrate when the article is received in the aerosol-generating device, it has been found that it is desirable to design the article so that air can enter the article through at least the exterior of the substrate to be heated, instead of or in addition to entering the device through the upstream end. Summary of the Invention [Problem to be solved by the invention]

[0005] Furthermore, it would be desirable to provide such an aerosol-generating rod or article that can be efficiently and rapidly manufactured without requiring extensive modifications of existing equipment. It would also be desirable to provide new and improved aerosol-generating rods or articles that can provide a satisfactory aerosol delivery to the user more quickly and that generally allow finer control of the aerosol delivery during use. It would be particularly desirable to provide such new and improved aerosol-generating rods or articles that can generate a satisfactory aerosol delivery to the user at lower temperatures while still heating the tobacco-containing substrate for normal consumption. [Means for solving the problem]

[0006] The present disclosure relates to an aerosol-generating rod or article for generating an inhalable aerosol upon heating. The aerosol-generating rod or article may comprise a first segment. The aerosol-generating rod or article may comprise a second segment. The aerosol-generating rod or article may comprise an aerosol-generating element. The aerosol-generating rod or article may comprise a wrapper. The second segment may be permeable, preferably air permeable. The aerosol-generating element may be located between the first segment and the second segment. The second segment may be located downstream of the aerosol-generating element. The wrapper may surround the first segment, the aerosol-generating element, and the second segment. A portion of the wrapper surrounding the aerosol-generating element may be air permeable such that the wrapper establishes fluid communication between the exterior of the aerosol-generating article and the aerosol-generating element.

[0007] The first segment may be a first plug segment. The second segment may be a second plug segment. The first segment may be referred to as an upstream segment. The second segment may be referred to as a downstream segment.

[0008] The aerosol generating element may be located downstream of the first segment. The aerosol generating element may be located immediately downstream of the first segment. The second segment may be located immediately downstream of the aerosol generating element. The aerosol generating element may be located immediately between the first segment and the second segment. The first plug segment may abut the aerosol generating element. The second plug segment may abut the aerosol generating element. The first plug segment, the aerosol generating element (or the substrate), and the second plug segment may be axially aligned with one another. The first plug segment, the aerosol generating element (or the substrate), and the second plug segment may be arranged consecutively.

[0009] According to the present invention, there is provided an aerosol-generating article or rod for generating an inhalable aerosol upon heating. The aerosol-generating article or rod comprises a first plug segment, a second plug segment, an aerosol-generating element, and a wrapper. The second plug segment is permeable, preferably air-permeable. The aerosol-generating element is positioned immediately between the first segment (plug segment) and the second segment (plug segment). The second plug segment is located downstream of the aerosol-generating element. The wrapper surrounds the first plug segment, the aerosol-generating element, and the second plug segment. A portion of the wrapper surrounding the aerosol-generating element is air-permeable such that the wrapper establishes fluid communication between the exterior of the aerosol-generating article or rod and the aerosol-generating element.

[0010] The present invention and disclosure provide a novel and compact aerosol generating rod or article configuration that allows flexible control over air entrapment in the aerosol generating element. By providing two plug segments on either side of the aerosol generating element and a wrapper that is air permeable (or porous) at least where it overlaps with the aerosol generating element, the amount of air entering the aerosol generating element axially through the upstream plug and radially or transversely through the air permeable portion of the wrapper can be easily controlled by adjusting the permeability properties of the first upstream plug segment and the wrapper. Having the aerosol generating element immediately between the first and second plug segments further ensures that the permeability properties of the plug segments significantly affect aerosol delivery to the user.

[0011] Establishing fluid communication through the air-permeable wrapper between at least the exterior of the article and the aerosol generating element ensures that air enters the aerosol generating element directly without having to flow through the article and any other components upstream of the aerosol generating element. In the context of externally heating the device, the air flowing directly into the aerosol generating element is partially heated as it flows through or past the external heater. This essentially allows for faster and more efficient heating of the aerosol generating element since the air entering through the wrapper is likely to be hotter than the air entering the upstream end of the article substantially axially, thereby reducing the initial delay in aerosol generation and delivery seen with existing aerosol generating articles and systems when a user begins consumption.

[0012] Furthermore, by providing two adjacent segments on each side of the aerosol generating element, any pieces or segments of the aerosol generating element are prevented from escaping from both sides of the aerosol generating article, this advantage is further enhanced by providing a segment immediately adjacent each side of the aerosol generating element, as this ensures that the contents of the aerosol generating element remain in place and cannot migrate to other locations in the article or escape from the article or rod.

[0013] According to the present disclosure, there is provided an aerosol-generating article or rod for generating an inhalable aerosol upon heating. The aerosol-generating article or rod may comprise a first plug segment, a second plug segment, an aerosol-generating element, and a wrapper. The second plug segment may be permeable. The aerosol-generating element may be located immediately between the first segment (plug segment) and the second segment (plug segment). The second plug segment may be located downstream of the aerosol-generating element. The wrapper may surround the first plug segment, the aerosol-generating element, and the second plug segment. A portion of the wrapper surrounding the aerosol-generating element may be air permeable. The air permeability of the permeable portion of the wrapper may be at least about 2500 Coresta units. The air permeability of the permeable portion of the wrapper may be at least about 5000 Coresta units.

[0014] The term "aerosol-generating article" is used herein to mean an article in which an aerosol-generating substrate is heated to generate an inhalable aerosol for delivery to a user. As used herein, the term "aerosol-generating substrate" means a substrate capable of releasing a volatile compound upon heating to generate an aerosol.

[0015] 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 aerosol-generating substrate. Aerosol-generating articles of this type are described in the prior art, for example in EP0822670.

[0016] As used herein, the term "aerosol-generating device" refers to a device that includes a heater or heating element that interacts with an aerosol-generating (or aerosol-forming) substrate of an aerosol-generating article to generate an aerosol.

[0017] The term "rod" as used herein in connection with the present invention is used to denote a generally elongated element, preferably a cylindrical element of substantially circular, oval or elliptical cross section. The aerosol-generating article of the present invention may also be referred to as an aerosol-generating rod throughout this disclosure. The aerosol-generating article of the present invention may comprise an aerosol-generating rod and, downstream of the rod, a downstream section. The downstream section may also be referred to as the "filter" of the aerosol-generating article. Within this disclosure, the term "aerosol-generating rod" refers to a portion of an article comprising or consisting of an aerosol-generating element and two adjacent (plug) segments.

[0018] The term "longitudinal" as used herein refers to a direction corresponding to a major longitudinal axis of the aerosol-generating article extending between the upstream and downstream ends of the aerosol-generating article. The terms "upstream" and "downstream" as used herein describe the relative positions of an element (or part of an element) of the aerosol-generating article with respect to the direction in which aerosol is transported through the aerosol-generating article during use.

[0019] In 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.

[0020] 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.

[0021] As mentioned above, the aerosol-generating article may further comprise a downstream section at a location downstream of the aerosol-generating rod. The downstream section may include one or more downstream elements.

[0022] The downstream section may include a hollow section between the mouth end of the aerosol-generating article and the aerosol-generating rod. The hollow section may comprise a hollow tubular element.

[0023] As used herein, terms such as "hollow tubular segment" and "hollow tubular element" are used to mean 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 an upstream end of the tubular element or segment and a 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.

[0024] The terms "immediately" or "immediately" preferably refer to two components that are adjacent to each other or have no space or gap between them.

[0025] In the context of the present invention, a hollow tubular segment or hollow tubular element provides an unrestricted flow path. This means that the hollow tubular segment or hollow tubular element provides a negligible level of resistance to withdrawal (RTD). The term "negligible level of RTD" is used to describe an RTD of less than 1 mmH2O per 10 millimeters of length of a hollow tubular segment or hollow tubular element, preferably less than 0.4 mmH2O per 10 millimeters of length of a hollow tubular segment or hollow tubular element, more preferably less than 0.1 mmH2O per 10 millimeters of length of a hollow tubular segment or hollow tubular element.

[0026] Thus, the flow channels should not include any components that would impede the longitudinal air flow. Preferably, the flow channels are substantially empty.

[0027] As used herein, a "hollow tubular segment" or "hollow tubular element" may also be referred to as a "hollow tube" or "hollow tube segment."

[0028] The aerosol-generating article may further comprise an upstream section at a location upstream of the aerosol-generating rod. The upstream section may comprise one or more upstream elements. The upstream section may include an upstream element disposed immediately upstream of the aerosol-generating rod, i.e., immediately upstream of the first plug segment.

[0029] An aerosol-generating rod or article according to the present invention may be substantially cylindrical and have an outer diameter of at least about 4 millimeters. More preferably, the aerosol-generating rod has an outer diameter of at least about 5 millimeters. Even more preferably, the aerosol-generating rod has an outer diameter of at least about 6 millimeters.

[0030] Preferably, the aerosol-generating rod has an outer diameter of about 12 millimeters or less. More preferably, the aerosol-generating rod has an outer diameter of about 11 millimeters or less. Even more preferably, the aerosol-generating rod has an outer diameter of about 8 millimeters or less.

[0031] The aerosol-generating rod may have an outer diameter of about 4 mm to about 12 mm, preferably about 5 mm to about 12 mm, more preferably about 6 mm to about 12 mm. The aerosol-generating rod may have an outer diameter of about 4 mm to about 11 mm, preferably about 5 mm to about 11 mm, more preferably about 6 mm to about 11 mm. The aerosol-generating rod may have an outer diameter of about 4 mm to about 8 mm, preferably about 5 mm to about 8 mm, more preferably about 6 mm to about 8 mm.

[0032] In general, it has 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 rod-shaped element, and a sufficient amount of vaporized species is released from the aerosol-generating substrate to form a desired amount of aerosol. At the same time, without wishing to be bound by theory, it is understood that the smaller the diameter of the rod-shaped element, the faster the heat provided to the aerosol-generating rod can penetrate its entire volume. Nevertheless, if the diameter of the rod-shaped element is too small, the amount of available aerosol-forming substrate is reduced, and the volume-to-surface ratio of the aerosol-generating substrate becomes less favorable. This is particularly important for aerosol-generating articles that are configured to be heated by an external heater.

[0033] Aerosol-generating rod diameters falling within the ranges described herein are particularly advantageous in terms of the balance between energy consumption and aerosol delivery. This advantage is particularly realized when an aerosol-generating article comprising an aerosol-generating rod with a diameter described herein is used in combination with an external heater disposed around the outer surface of the aerosol-generating rod or article. It has been observed that under these operating conditions, less thermal energy is required to achieve a sufficiently high temperature at the core of the aerosol-generating rod and at the core of the article comprising the rod. Thus, when operating at a lower temperature, the desired target temperature at the core of the aerosol-generating rod can be achieved within a desirably reduced time frame and with less energy consumption.

[0034] The overall length of the aerosol-generating rod may be at least about 8 millimeters. Preferably, the overall length of the aerosol-generating rod is at least about 9 millimeters. More preferably, the overall length of the aerosol-generating rod is at least about 10 millimeters.

[0035] Preferably, the total length of the aerosol-generating rod is about 27 millimeters or less. More preferably, the total length of the aerosol-generating rod is about 23 millimeters or less. Even more preferably, the total length of the aerosol-generating rod is about 19 millimeters or less.

[0036] The total length of the aerosol-generating rod may be about 8 mm to about 27 mm, preferably about 9 mm to about 27 mm, more preferably about 10 mm to about 27 mm. The total length of the aerosol-generating rod may be about 8 mm to about 23 mm, preferably about 9 mm to about 23 mm, more preferably about 10 mm to about 23 mm. The total length of the aerosol-generating rod may be about 8 mm to about 19 mm, preferably about 9 mm to about 19 mm, more preferably about 10 mm to about 19 mm.

[0037] The plug segment of the present disclosure may have an outer diameter that is the same as the outer diameter of the aerosol generating element. The plug segment preferably comprises a cross section of solid material. In other words, the plug segment does not define any cavities, gaps, or voids other than those already defined by the material properties itself, such as pores. This ensures that the plug segment prevents the material of the aerosol generating element from inadvertently exiting the article.

[0038] The plug segment may have one or more openings or through holes defined through the length of the plug segment. The number and location of the openings or through holes may depend on the nature of the aerosol generating element. Providing such openings ensures that the resistance to withdrawal (RTD) of the article is beneficially low. Either or both of the first and second plug segments may include such openings or through holes. Each such opening may define a cavity within the plug segment. The plug segment may be a hollow tubular segment, preferably having a relatively thick wall.

[0039] The first upstream plug segment may be substantially impermeable. The first plug segment may be substantially air impermeable such that air does not pass through the first plug segment and into the aerosol generating element or segment. The material of the first upstream plug segment may be substantially impermeable. As a result, air does not flow into the aerosol generating rod or article through its upstream end, but may enter the aerosol generating article primarily through the permeable or porous portion or region of the wrapper.

[0040] The first upstream plug segment may be substantially permeable. The material of the first upstream plug segment may be substantially permeable. The first plug segment may be substantially air permeable (or porous) such that air may pass through the first plug segment material and into the aerosol generating element or segment. As a result, air may flow into the aerosol generating rod or article through its upstream end and also into the aerosol generating article through the permeable or porous portion or region of the wrapper.

[0041] Unless otherwise specified, the resistance to draw (RTD) of a component or aerosol-generating article or rod may be measured according to ISO 6565-2015. RTD refers to the pressure required to force air through the entire length of the component. The term "pressure drop" or "draw resistance" of a component or article may also refer to "resistance to draw." These terms generally refer to measurements according to ISO 6565-2015 being performed normally 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.

[0042] The resistance to withdrawal per unit length of a particular component (or element) of an aerosol-generating article, such as the first plug segment, the aerosol-generating element, or the second plug segment, can be calculated by dividing the measured resistance to withdrawal of the component by the total axial length of the component. The RTD per unit length refers to the pressure required to force air through a unit length of the component. Throughout this disclosure, unit length refers to a length of 1 mm. Thus, to derive the RTD per unit length of a particular part, a test specimen of a particular length of the component, for example 15 mm, can be used for the measurement. The RTD of such a specimen is measured according to ISO6565-2015. For example, if the measured RTD is about 15 mmH2O, then the RTD per unit length of the component is about 1 mmH2O per mm. The RTD per unit length of a component depends on the structural properties of the material used in the component, as well as the cross-sectional shape or geometry of the component, among other factors.

[0043] The relative RTD, or RTD per unit length of the first or second plug segment may be from about 0 mmH2O per mm to about 3 mmH2O per mm. The RTD per unit length of the first or second plug segment may be from about 0 mmH2O per mm to about 2.5 mmH2O per mm. The RTD per unit length of the first or second plug segment may be from about 0 mmH2O per mm to about 2 mmH2O per mm. The RTD per unit length of the first or second plug segment may be from about 0 mmH2O per mm to about 1 mmH2O per mm. The RTD per unit length of the first or second plug segment may be from about 0 mmH2O per mm to about 0.75 mmH2O per mm.

[0044] As described above, the relative RTD or RTD per unit length of the first or second plug segment may be between about 0 mmH2O per mm and about 3 mmH2O per mm. The RTD per unit length of the first or second plug segment may be greater than about 0 mmH2O per mm and less than about 2.5 mmH2O per mm. The RTD per unit length of the first or second plug segment may be greater than about 0 mmH2O per mm and less than about 2 mmH2O per mm. The RTD per unit length of the first or second plug segment may be greater than about 0 mmH2O per mm and less than about 1 mmH2O per mm. The RTD per unit length of the first or second plug segment may be greater than about 0 mmH2O per mm and less than about 0.75 mmH2O per mm.

[0045] The RTD per unit length of the first plug segment or the second plug segment may be greater than about 0 mmH2O per mm. Thus, the RTD per unit length of the first plug segment or the second plug segment may be about 0 mmH2O per mm to about 3 mmH2O per mm. The RTD per unit length of the first plug segment or the second plug segment may be about 0 mmH2O per mm to about 2.5 mmH2O per mm. The RTD per unit length of the first plug segment or the second plug segment may be about 0 mmH2O per mm to about 2 mmH2O per mm. The RTD per unit length of the first plug segment or the second plug segment may be about 0 mmH2O per mm to about 1 mmH2O per mm. The RTD per unit length of the first plug segment or the second plug segment may be about 0 mmH2O per mm to about 0.75 mmH2O per mm.

[0046] The withdrawal resistance of the first plug segment or the second plug segment may be greater than about 0 mmH2O and less than about 10 mmH2O. The withdrawal resistance of the first plug segment or the second plug segment may be greater than 0 mmH2O and less than about 5 mmH2O. The withdrawal resistance of the first plug segment or the second plug segment may be greater than 0 mmH2O and less than about 2 mmH2O. The withdrawal resistance of the first plug segment or the second plug segment may be greater than 0 mmH2O and less than about 1 mmH2O.

[0047] The RTD characteristics of the first plug segment and the second plug segment may be the same. The RTD characteristics of the first plug segment and the second plug segment may be different. For example, when the RTD characteristics are different, it is preferable that the RTD (or RTD per unit length) of the second plug segment is lower than the RTD (or RTD per unit length) of the first plug segment. In this way, the second plug segment provides a barrier to prevent the material of the aerosol generating element from being removed, while not substantially increasing the RTD of the article.

[0048] The outer diameter of the first plug segment may be substantially the same as the outer diameter of the rod.

[0049] The first plug segment may have a length of at least about 2 millimeters. Preferably, the first plug segment has a length of at least about 3 millimeters. More preferably, the first plug segment has a length of at least about 4 millimeters.

[0050] The first plug segment may have a length of up to about 10 millimeters. Preferably, the first plug segment has a length of about 7 millimeters or less. More preferably, the first plug segment has a length of about 5 millimeters or less.

[0051] The first plug segment may have a length of about 2 mm to about 10 mm, preferably about 3 mm to about 10 mm, and more preferably about 4 mm to about 10 mm. The first plug segment may have a length of about 2 mm to about 17 mm, preferably about 3 mm to about 7 mm, and more preferably about 4 mm to about 7 mm. The first plug segment may have a length of about 2 mm to about 5 mm, preferably about 3 mm to about 5 mm, and more preferably about 4 mm to about 5 mm.

[0052] In an aerosol-generating rod or article according to the invention, the ratio of the length of the first plug segment to the length of the aerosol-generating element is at least about 0.15. Preferably, the ratio of the length of the first plug segment to the length of the aerosol-generating element is at least about 0.2. More preferably, the ratio of the length of the first plug segment to the length of the aerosol-generating element is at least about 0.3.

[0053] The ratio of the length of the first plug segment to the length of the aerosol generating element is preferably about 0.5 or less. More preferably, the ratio of the length of the first plug segment to the length of the aerosol generating element is about 0.45 or less. Even more preferably, the ratio of the length of the first plug segment to the length of the aerosol generating element is about 0.4 or less.

[0054] The ratio of the length of the first plug segment to the length of the aerosol-generating element may be about 0.15 to about 0.5, preferably about 0.2 to about 0.5, more preferably about 0.3 to about 0.5. The ratio of the length of the first plug segment to the length of the aerosol-generating element may be about 0.15 to about 0.45, preferably about 0.2 to about 0.45, more preferably about 0.3 to about 0.45. The ratio of the length of the first plug segment to the length of the aerosol-generating element may be about 0.15 to about 0.4, preferably about 0.2 to about 0.4, more preferably about 0.3 to about 0.4.

[0055] The second downstream plug segment or the first upstream plug segment may comprise a plug of porous substrate. The plug of porous substrate may be substantially free of the aerosol-generating compound.

[0056] The first plug segment or the second plug segment may be formed of a fibrous material. The first plug segment or the second plug segment may be formed of a porous material. The first plug segment or the second plug segment may be formed of a fluid or air permeable material. The first plug segment or the second plug segment may be formed of a fluid or air impermeable material. The first plug segment or the second plug segment may be formed of a biodegradable material. The first plug segment or the second plug segment may be formed of a cellulose material, such as cellulose acetate. For example, the first plug segment or the second plug segment may be formed of a bundle of cellulose acetate fibers having a denier of about 10 to about 15 per filament. For example, the first plug segment or the second plug segment may be formed of a relatively low density cellulose acetate tow, such as a cellulose acetate tow containing fibers of about 12 denier per filament, and may provide an RTD of about 0.8 to about 2.5 mmH2O per mm per unit length.

[0057] The first plug segment or the second plug segment may be made of a polylactic acid-based material. The first plug segment or the second plug segment may be made of a bioplastic material, preferably a starch-based bioplastic material. The first plug segment or the second plug segment may be made by injection molding or extrusion molding. Bioplastic-based materials are advantageous because they can provide a simple and inexpensive to manufacture first plug segment or second plug segment structure with a specific and complex cross-sectional profile that can include multiple relatively large airflow channels extending through the first plug segment or second plug segment material, providing suitable RTD characteristics.

[0058] The first or second plug segment may be formed from a sheet of suitable material that is crimped, pleated, assembled, woven, or folded into an element that defines a plurality of longitudinally extending channels. Such sheets of suitable material may be formed from paper, cardboard, and polymers such as polylactic acid, or any other cellulosic, paper, or bioplastic-based material. A cross-sectional profile of such a first or second plug segment may exhibit randomly oriented channels.

[0059] The first or second plug segment may be formed in any other suitable manner. For example, the first or second plug segment may be formed from a bundle of longitudinally extending tubes. The longitudinally extending tubes may be formed from polylactic acid. The first or second plug segment may be formed by extrusion, molding, lamination, injection or chopping of a suitable material. Thus, it is preferred that there is a low pressure drop (or RTD) from the upstream end of the first or second plug segment to the downstream end of the first or second plug segment.

[0060] Advantageously, the plug segment may help support the aerosol-generation segment or element and prevent dislodging of any of the aerosol-generating material, such as tobacco material, contained in the aerosol-generation segment. Additionally, the plug segment contributes to the overall structural strength of the rod, facilitating its handling, particularly during manufacture.

[0061] Preferably, the second (downstream) plug segment does not contribute substantially to the overall RTD of the aerosol-generating rod.

[0062] The outer diameter of the second plug segment may be substantially the same as the outer diameter of the rod.The outer diameter of the second plug segment may be substantially the same as the outer diameter of the first plug segment.

[0063] The second plug segment may have a length of at least about 2 millimeters. Preferably, the second plug segment has a length of at least about 3 millimeters. More preferably, the second plug segment has a length of at least about 4 millimeters.

[0064] The second plug segment may have a length of up to about 10 millimeters. Preferably, the second plug segment has a length of about 7 millimeters or less. More preferably, the second plug segment has a length of about 5 millimeters or less.

[0065] The second plug segment may have a length of about 2 mm to about 10 mm, preferably about 3 mm to about 10 mm, and more preferably about 4 mm to about 10 mm. The second plug segment may have a length of about 2 mm to about 17 mm, preferably about 3 mm to about 7 mm, and more preferably about 4 mm to about 7 mm. The second plug segment may have a length of about 2 mm to about 5 mm, preferably about 3 mm to about 5 mm, and more preferably about 4 mm to about 5 mm.

[0066] The components of the aerosol-generating rod, which will be described in more detail, are surrounded by a wrapper, which may be a paper wrapper or a non-paper wrapper, and which may also align or attach the components of the aerosol-generating rod or article to one another.

[0067] Suitable paper wrappers for use in the present invention (or in the arrangements of the present disclosure) 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 the present invention (or in the arrangements of the present disclosure) are known in the art and include, but are not limited to, sheets of homogenized tobacco material.

[0068] As described above, a wrapper or packaging material surrounds the first plug segment, the aerosol generating element, and the second plug segment. The wrapper includes a substantially permeable region or portion. The permeable region or portion may overlap or overlap at least a portion of the aerosol generating element. The permeable region of the wrapper is configured to establish fluid communication between the exterior of the aerosol generating article and the aerosol generating element. The permeable region or portion is preferably a substantially air permeable region or portion.

[0069] The permeable region of the wrapper may partially or completely surround the periphery or perimeter of the aerosol-generating element.

[0070] The permeable region of the wrapper may overlap at least about 10 percent of the outer surface of the aerosol generating element. The permeable region of the wrapper may overlap at least about 20 percent of the outer surface of the aerosol generating element. The permeable region of the wrapper may overlap at least about 25 percent of the outer surface of the aerosol generating element. The permeable region of the wrapper may overlap at least about 40 percent of the outer surface of the aerosol generating element. The permeable region of the wrapper may overlap at least about 50 percent of the outer surface of the aerosol generating element. The permeable region of the wrapper may overlap at least about 60 percent of the outer surface of the aerosol generating element. The permeable region of the wrapper may overlap at least about 75 percent of the outer surface of the aerosol generating element. The permeable region of the wrapper may overlap at least about 80 percent of the outer surface of the aerosol generating element. The permeable region of the wrapper preferably overlaps or overlaps the entire outer surface of the aerosol generating element.

[0071] Preferably, the entire permeable portion (or region) of the wrapper overlaps or overlaps the aerosol-generating element. Preferably, the remainder of the wrapper is not permeable. Preferably, the portion or portions of the wrapper that do not overlap or overlap the aerosol-generating element are not permeable. Preferably, the wrapper comprises a permeable portion (or region) and an impermeable portion.

[0072] The length of the permeable portion of the wrapper may be at least about 10 percent of the length of the aerosol generating element. The length of the permeable portion of the wrapper may be at least about 20 percent of the length of the aerosol generating element. The length of the permeable portion of the wrapper may be at least about 25 percent of the length of the aerosol generating element. The length of the permeable portion of the wrapper may be at least about 40 percent of the length of the aerosol generating element. The length of the permeable portion of the wrapper may be at least about 50 percent of the length of the aerosol generating element. The length of the permeable portion of the wrapper may be at least about 60 percent of the length of the aerosol generating element. The length of the permeable portion of the wrapper may be at least about 75 percent of the length of the aerosol generating element. The length of the wrapper of the permeable portion may be the same as the length of the wrapper itself. The length of the permeable portion of the wrapper may be at least about 80 percent of the length of the aerosol generating element. The length of the wrapper is preferably the same as the length of the aerosol generating rod or aerosol generating article.

[0073] The surface area of ​​the permeable portion (or region) of the wrapper may be at least about 10 percent of the outer surface of the aerosol generating element. The surface area of ​​the permeable portion of the wrapper may be at least about 20 percent of the outer surface of the aerosol generating element. The surface area of ​​the permeable portion of the wrapper may be at least about 25 percent of the outer surface of the aerosol generating element. The surface area of ​​the permeable portion of the wrapper may be at least about 40 percent of the outer surface of the aerosol generating element. The surface area of ​​the permeable portion of the wrapper may be at least about 50 percent of the outer surface of the aerosol generating element. The surface area of ​​the permeable portion of the wrapper may be at least about 60 percent of the outer surface of the aerosol generating element. The surface area of ​​the permeable portion of the wrapper may be at least about 75 percent of the outer surface of the aerosol generating element. The surface area of ​​the permeable portion of the wrapper may be at least about 80 percent of the outer surface of the aerosol generating element. The surface area of ​​the permeable portion of the wrapper may be the same as the outer surface of the aerosol generating element. The surface area of ​​the permeable portion of the wrapper may be the same as the surface area of ​​the wrapper itself.

[0074] The permeable portion may extend around at least about 10 percent of the circumference or perimeter of the aerosol generating element. The permeable portion may extend around at least about 25 percent of the circumference or perimeter of the aerosol generating element. The permeable portion may extend around at least about 50 percent of the circumference or perimeter of the aerosol generating element. The permeable portion may extend around at least about 75 percent of the circumference or perimeter of the aerosol generating element. The permeable portion may extend around the entire circumference or perimeter of the aerosol generating element. In other words, the permeable portion may completely surround the aerosol generating element.

[0075] The inventors have found that the dimensions of the permeable regions or portions of the wrapper can be optimized for different articles, along with a particular range of air permeability values ​​for the wrapper, depending on the airflow requirements of the article and the aerosol-generating substrate. For example, for a particular article and aerosol-generating substrate, it may be beneficial to provide a wrapper with a relatively large permeable region (preferably according to the present disclosure) to distribute air entrapment across the aerosol-generating substrate.

[0076] In some cases, it may be beneficial to provide a wrapper with a relatively small region of permeability in order to focus air entrapment at a specific location around the aerosol-generating element, which may be advantageous in ensuring compatibility between the aerosol-generating article and the device with which it is adapted for use.

[0077] The term "external surface" preferably refers to an outer surface that extends longitudinally, parallel to the longitudinal axis defined by the article. The term "external surface" may refer to the "longitudinal outer surface."

[0078] The entire wrapper may be permeable (air permeable).

[0079] The air permeability of the permeable area of ​​the wrapper or of the wrapper may be greater than about 2500 Coresta units. The air permeability of the permeable area of ​​the wrapper or of the wrapper may be greater than about 5000 Coresta units. The air permeability of the permeable area of ​​the wrapper or of the wrapper may be greater than about 7500 Coresta units.

[0080] The air permeability of the permeable region of the wrapper or of the wrapper may be less than about 12000 Coresta units. The air permeability of the permeable region of the wrapper or of the wrapper may be less than about 11000 Coresta units. The air permeability of the permeable region of the wrapper or of the wrapper may be less than about 10000 Coresta units.

[0081] The air permeability of the permeable region of the wrapper, or of the wrapper, may be at least about 2500 Coresta units. The air permeability of the permeable region of the wrapper, or of the wrapper, may be at least about 5000 Coresta units. The air permeability of the permeable region of the wrapper, or of the wrapper, may be at least about 7500 Coresta units.

[0082] The air permeability of the permeable area of ​​the wrapper or of the wrapper may be about 12000 Coresta units or less. The air permeability of the permeable area of ​​the wrapper or of the wrapper may be about 11000 Coresta units or less. The air permeability of the permeable area of ​​the wrapper or of the wrapper may be about 10000 Coresta units or less.

[0083] The air permeability of the permeable region of the wrapper or of the wrapper may be from about 2500 Coresta units to about 12000 Coresta units. The air permeability of the permeable region of the wrapper or of the wrapper may be from about 5000 Coresta units to about 12000 Coresta units. The air permeability of the permeable region of the wrapper or of the wrapper may be from about 7500 Coresta units to about 12000 Coresta units.

[0084] The air permeability of the permeable region of the wrapper or of the wrapper may be from about 2500 Coresta units to about 11000 Coresta units. The air permeability of the permeable region of the wrapper or of the wrapper may be from about 5000 Coresta units to about 11000 Coresta units. The air permeability of the permeable region of the wrapper or of the wrapper may be from about 7500 Coresta units to about 11000 Coresta units.

[0085] The air permeability of the permeable region of the wrapper or of the wrapper may be from about 2500 Coresta units to about 10000 Coresta units. The air permeability of the permeable region of the wrapper or of the wrapper may be from about 5000 Coresta units to about 10000 Coresta units. The air permeability of the permeable region of the wrapper or of the wrapper may be from about 7500 Coresta units to about 10000 Coresta units.

[0086] Air permeability in Coresta units is the amount of air in cubic centimetres that passes through a square centimetre wrapper per minute at a constant pressure difference of 1 kilopascal (i.e., 1 Coresta unit is 1 cm at a pressure difference of 1 kPa). 3 / min.cm 2 Air permeability in Coresta units may be measured according to ISO 2965:2009.

[0087] Providing a wrapper with a relatively high (air) permeability advantageously ensures that the wrapper allows a substantial amount of air to enter the aerosol-generating article and transport the generated aerosol to the user without the need to admit air through the upstream end of the article or rod.

[0088] The wrapper should have a basis weight of at least about 10 grams per square meter (gsm or g / m 2 The wrapper may have a basis weight of at least about 15 gsm.

[0089] The wrapper may have a basis weight of less than about 30 gsm.The wrapper may have a basis weight of less than about 25 gsm.

[0090] The basis weight of the wrapper may be from about 10 gsm to about 30 gsm.The basis weight of the wrapper may be from about 15 gsm to about 25 gsm.

[0091] The thickness of the wrapper may be at least about 0.01 mm. The thickness of the wrapper may be at least about 0.02 mm. The thickness of the wrapper may be at least about 0.03 mm.

[0092] The thickness of the wrapper may be less than about 0.1 mm. The thickness of the wrapper may be less than about 0.08 mm. The thickness of the wrapper may be less than about 0.07 mm.

[0093] The thickness of the wrapper may be from about 0.01 mm to about 0.1 mm. The thickness of the wrapper may be from about 0.02 mm to about 0.08 mm. The thickness of the wrapper may be from about 0.03 mm to about 0.07 mm.

[0094] The aerosol-generating element is preferably visible through the wrapper. The aerosol-generating element may be at least partially visible through the wrapper. The wrapper, or at least a portion of the wrapper surrounding the aerosol-generating element, may be substantially translucent or substantially transparent. The transparent portion of the wrapper may be substantially translucent or substantially transparent.

[0095] As used herein, the term "substantially transparent" is used to describe a material that allows at least a sufficient percentage of incident light to pass through it so that one can see through the material. In the present invention, a substantially transparent wrapper allows sufficient light to pass through the wrapper so that the underlying aerosol-generating element can be seen through the wrapper. The transparency of a substantially transparent wrapper may be evaluated according to ASTM D1003-13.

[0096] The wrapper may be completely transparent. The transparent portion of the wrapper may have a low level of transparency while still emitting enough light so that the aerosol-generating elements are still visible. Preferably, "transparent" means a total light transmittance percentage of 40% or more, more preferably 50% or more, even more preferably 60% or more, and most preferably 70% or more, as measured using a Hunterlab Colorquest XE spectrophotometer. The term "semi-transparent" refers to a material that allows some level of light to pass through, especially one that has some diffusion.

[0097] Preferably, the light transmittance of the portion of the wrapper surrounding the aerosol-generating element is at least 40 percent, preferably at least 50 percent, and even more preferably at least 60 percent. A wrapper that is at least partially substantially transparent or translucent allows a user to view the contents of the aerosol-generating element of the article that the user intends to use.

[0098] The porous or air permeable nature of the packaging material or wrapper may allow a user to see the contents enclosed by the wrapper. For example, the wrapper may include (or be made from) a tea bag or tea bag-like material. The wrapper may include a biodegradable material. The wrapper may include polylactic acid (PLA). The wrapper may include PLA mesh. The wrapper may include a material based on or formed from corn starch. The wrapper material may include wood or plant fibers.

[0099] The wrapper may comprise a polymeric or plastic material that is air permeable, such as nylon. The wrapper may comprise a paper material, such as filter paper. The inventors have found that it is possible to form a wrapper from such materials that has a relatively high permeability (as indicated by the Coresta values ​​above) that is suitably air permeable, while still allowing a user to view the contents of the aerosol generating element to identify the type of aerosol generating element that the user is intending to use.

[0100] The wrapper may also be impregnated with a flavoring agent. Thus, a portion of such wrapper flavoring agent may be entrained or released into the air flowing through the air-permeable wrapper into the aerosol-generating article or element. Such flavoring agents may be liquids or gels that may be applied to any other element or component of the aerosol-generating article, such as the aerosol-generating substrate as defined herein.

[0101] The outer diameter of the aerosol-generating element is preferably substantially the same as the outer diameter of the rod. The aerosol-generating element may be referred to as an aerosol-generating segment or substrate.

[0102] The aerosol generating element may have a length of at least about 5 millimeters. Preferably, the aerosol generating element has a length of at least about 7 millimeters. More preferably, the aerosol generating element has a length of at least about 8 millimeters.

[0103] The aerosol-generating element may have a length of up to about 25 millimeters. Preferably, the aerosol-generating element has a length of about 20 millimeters or less. More preferably, the aerosol-generating substrate has a length of about 13 millimeters or less.

[0104] The aerosol-generating element may have a length of about 5 mm to about 25 mm, preferably about 7 mm to about 25 mm, more preferably about 8 mm to about 25 mm. The aerosol-generating element may have a length of about 5 mm to about 20 mm, preferably about 7 mm to about 20 mm, more preferably about 8 mm to about 20 mm. The aerosol-generating element may have a length of about 5 mm to about 13 mm, preferably about 7 mm to about 13 mm, more preferably about 8 mm to about 13 mm.

[0105] The aerosol-generating element is a solid aerosol-generating substrate that includes tobacco plant material. The term "tobacco plant material" is used herein to mean material that forms part of any plant member of the genus Nicotiana.

[0106] The aerosol-generating element may include a homogenized tobacco material.

[0107] Homogenized tobacco material is an example of a "homogenized plant material." As used herein, the term "homogenized plant material" encompasses any plant material formed by agglomeration of plant particles. For example, a sheet or web of homogenized tobacco material for an aerosol-generating substrate of the present invention may be formed by agglomerating particles of tobacco material obtained by grinding, crushing, or comminuting one or more of tobacco lamina and tobacco stems. Homogenized plant material, such as homogenized tobacco material, may be produced by casting, extrusion, a papermaking process, or any other suitable process known in the art.

[0108] The homogenized tobacco material can be provided in any suitable form. For example, the homogenized tobacco material may be in the form of one or more sheets. As used herein with respect to the present invention, the term "sheet" describes a layered element having a width and length substantially greater than its thickness.

[0109] The homogenized tobacco material may be in the form of a plurality of pellets or granules.

[0110] The homogenized tobacco material may be in the form of multiple strands, strips, or pieces. As used herein, the term "strand" describes an elongated element of material having a width and length substantially greater than its width and thickness. The term "strand" should be considered to encompass strips, pieces, and any other homogenized tobacco material having a similar form. Strands of homogenized tobacco material may be formed from a sheet of homogenized tobacco material, for example, by cutting or chopping, or by other methods, such as extrusion methods.

[0111] The strands may be formed in situ within the aerosol-generating element as a result of splitting or cracking of the sheet of homogenized tobacco material during formation of the aerosol-generating element, for example as a result of crimping. The strands of homogenized tobacco material within the aerosol-generating element may be separated from one another. Each strand of homogenized tobacco material within the aerosol-generating element may be at least partially connected to an adjacent strand or strands along its length. For example, adjacent strands may be connected by one or more fibers. This may occur, for example, when strands are formed due to splitting of a sheet of homogenized tobacco material during manufacture of the aerosol-generating element, as described above.

[0112] The aerosol-generating element is preferably in the form of one or more sheets of homogenized tobacco material. The one or more sheets of homogenized tobacco material may be produced by a casting process. The one or more sheets of homogenized tobacco material may be produced by a paper making process. The one or more sheets described herein may each individually have a thickness of from 100 micrometers to 600 micrometers, preferably from 150 micrometers to 300 micrometers, and most preferably from 200 micrometers to 250 micrometers. Individual thickness refers to the thickness of an individual sheet, and combined thickness refers to the total thickness of all sheets that make up the aerosol-generating substrate. For example, if the aerosol-generating element is formed from two individual sheets, the combined thickness is the thickness of the two individual sheets, or the sum of the measured thicknesses of the two sheets, and the two sheets are stacked within the aerosol-generating substrate.

[0113] One or more of the sheets described herein may each individually have a weight of about 100 g / m 2 ~about 300g / m 2 The sheet may have a basis weight of 100 g.

[0114] One or more of the sheets described herein may each individually have a density of about 0.3 g / cm 3 ~Approx. 1.3g / cm 3 and may have a density of about 0.7 g / cm 3 ~Approx. 1.0g / cm 3 It is preferred that the density of the granular material is 0.01 to 0.05.

[0115] The one or more sheets of homogenized tobacco material are preferably in the form of an assembly of one or more sheets. As used herein, the term "assembly" means that the sheet of homogenized tobacco material is spiraled, folded, or otherwise compressed or pinched in a direction substantially transverse to the cylindrical axis of the plug or rod.

[0116] One or more sheets of homogenized tobacco material may be gathered transversely to their longitudinal axes and surrounded by a wrapper to form a continuous rod or plug.

[0117] One or more sheets of homogenized tobacco material may be advantageously crimped or similarly treated. As used herein, the term "crimped" refers to a sheet having a plurality of substantially parallel ridges or corrugations. One or more sheets of homogenized tobacco material may be embossed, debossed, perforated, or otherwise deformed to provide texture to one or both sides of the sheet.

[0118] Preferably, each sheet of homogenized tobacco material may be crimped to have a plurality of ridges or corrugations substantially parallel to the cylindrical axis of the plug. This process advantageously facilitates assembling the crimped sheets of homogenized tobacco material to form the plug. Preferably, one or more sheets of homogenized tobacco material may be assembled. It will be appreciated that the crimped sheets of homogenized tobacco material may have a plurality of substantially parallel ridges or corrugations that form acute or obtuse angles with respect to the cylindrical axis of the plug. The sheet may be crimped to an extent that the integrity of the sheet is disturbed at the plurality of parallel ridges or corrugations, causing separation of the material and resulting in the formation of pieces, strands, or strips of homogenized tobacco material.

[0119] One or more sheets of homogenized tobacco material may be cut into strands as mentioned above. The aerosol-generating substrate may include a plurality of strands of homogenized tobacco material. The strands may be used to form plugs. Typically, the width of such strands is about 5 millimeters, or about 4 millimeters, or about 3 millimeters, or about 2 millimeters, or less. The length of the strands may be greater than about 5 millimeters, may be about 5 millimeters to about 15 millimeters, may be about 8 millimeters to about 12 millimeters, or may be about 12 millimeters. The strands preferably have substantially the same length as one another. The length of the strands may be determined by the manufacturing process whereby the rod is cut into shorter plugs, the length of the strands corresponding to the length of the plugs. The strands are fragile and may break, especially during transition. In such cases, the length of some of the strands may be shorter than the length of the plugs.

[0120] The strands are preferably aligned with the longitudinal axis and extend longitudinally substantially along the length of the aerosol generating element, and thus are preferably aligned substantially parallel to one another.

[0121] The homogenized tobacco material may comprise up to about 95 weight percent plant particles on a dry weight basis. Preferably, the homogenized tobacco material comprises up to about 90 weight percent plant particles on a dry weight basis, more preferably comprises up to about 80 weight percent plant particles, more preferably comprises up to about 70 weight percent plant particles, more preferably comprises up to about 60 weight percent plant particles, and more preferably comprises up to about 50 weight percent plant particles.

[0122] For example, the homogenized tobacco material may contain, on a dry weight basis, from about 2.5 weight percent to about 95 weight percent plant particles, or from about 5 weight percent to about 90 weight percent plant particles, or from about 10 weight percent to about 80 weight percent plant particles, or from about 15 weight percent to about 70 weight percent plant particles, or from about 20 weight percent to about 60 weight percent plant particles, or from about 30 weight percent to about 50 weight percent plant particles.

[0123] Sheets of homogenized tobacco material used in the present invention may have a tobacco content of at least about 40 weight percent on a dry weight basis, more preferably at least about 50 weight percent on a dry weight basis, more preferably at least about 70 weight percent on a dry weight basis, and most preferably at least about 90 weight percent on a dry weight basis.

[0124] For purposes of the present invention, the term "tobacco particles" refers to particles of any plant member of the Nicotiana species. The term "tobacco particles" includes ground or powdered tobacco lamina, ground or powdered tobacco stems, tobacco dust, tobacco fines, and other particulate tobacco by-products formed during tobacco processing, handling, and shipping. Tobacco particles may be derived substantially entirely from tobacco lamina. In contrast, isolated nicotine and nicotine salts, although compounds derived from tobacco, are not considered tobacco particles for purposes of the present invention and are not included in the percentage of particulate plant material.

[0125] The tobacco particles may be prepared from one or more tobacco plant varieties. Any type of tobacco may be used in the blend. Examples of types of tobacco materials that may be used include, but are not limited to, sun-cured tobacco, flue-cured tobacco, burley tobacco, Maryland tobacco, Orient tobacco, Virginia tobacco, and other specialty tobaccos.

[0126] Flame-curing is a tobacco curing method used specifically with Virginia tobacco. During the flue-curing process, heated air is circulated through tightly packed tobacco. During the first stage, the tobacco leaves turn yellow and wither. During the second stage, the leaf lamina dries completely. During the third stage, the leaf stem dries completely.

[0127] Burley tobacco plays an important role in many tobacco blends. It has a unique flavor and aroma and the ability to absorb large amounts of casing.

[0128] Orient is a type of tobacco that has small leaves and high aromatic qualities. However, Orient tobacco has a milder flavor than, for example, Burley. Thus, Orient tobacco is generally used in relatively small proportions in tobacco blends.

[0129] Kasturi, Madura, and Jatim are subtypes of sun-cured tobacco that may be used. Preferably, Kasturi and flue-cured tobaccos are used in a blend to produce tobacco particles. Thus, the tobacco particles in the particulate plant material may comprise a blend of Kasturi and flue-cured tobaccos.

[0130] The tobacco particles may have a nicotine content of at least about 2.5 weight percent based on dry weight. More preferably, the tobacco particles may have a nicotine content of at least about 3 weight percent based on dry weight, even more preferably at least about 3.2 weight percent, even more preferably at least about 3.5 weight percent, and most preferably at least about 4 weight percent.

[0131] The aerosol-generating element may include a non-tobacco plant material. The homogenized tobacco material may include tobacco particles in combination with non-tobacco plant flavor particles. Preferably, the non-tobacco plant flavor particles are selected from one or more of ginger particles, eucalyptus particles, clove particles, and star anise particles. Preferably, the homogenized tobacco material includes at least about 2.5 weight percent of non-tobacco plant flavor particles on a dry weight basis, with the remaining plant particles being tobacco particles. Preferably, the homogenized tobacco material includes at least about 4 weight percent of non-tobacco plant flavor particles on a dry weight basis, more preferably at least about 6 weight percent of non-tobacco plant flavor particles, more preferably at least about 8 weight percent of non-tobacco plant flavor particles, more preferably at least about 10 weight percent of non-tobacco plant flavor particles. Preferably, the homogenized tobacco material includes up to about 20 weight percent of non-tobacco plant flavor particles, more preferably up to about 18 weight percent of non-tobacco plant flavor particles, more preferably up to about 16 weight percent of non-tobacco plant flavor particles.

[0132] The weight ratio of non-tobacco plant flavour particles and tobacco particles in the particulate plant material forming the homogenized tobacco material may vary depending on the desired flavour characteristics and composition of the aerosol generated from the aerosol-generating substrate during use. Preferably, the homogenized tobacco material comprises, on a dry weight basis, at least a 1:30 weight ratio of non-tobacco plant flavour particles to tobacco particles, more preferably at least a 1:20 weight ratio of non-tobacco plant flavour particles to tobacco particles, more preferably at least a 1:10 weight ratio of non-tobacco plant flavour particles to tobacco particles, and most preferably at least a 1:5 weight ratio of non-tobacco plant flavour particles to tobacco particles.

[0133] The homogenized tobacco material preferably comprises no more than 95 weight percent particulate plant material on a dry weight basis. Accordingly, the particulate plant material is typically combined with one or more other ingredients to form the homogenized tobacco material.

[0134] The homogenized tobacco material may further comprise a binder for modifying the mechanical properties of the particulate plant material, where the binder is included in the homogenized tobacco material during manufacture as described herein.Suitable extrinsic binders known to those skilled in the art are known in the art and include, but are not limited to, gums such as guar gum, xanthan gum, gum arabic and locust bean gum, cellulose binders such as hydroxypropyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, methyl cellulose and ethyl cellulose, polysaccharides such as starch, organic acids such as alginic acid, sodium alginate, conjugate base salts of organic acids such as agar and pectin, and combinations thereof.Preferably, the binder comprises guar gum.

[0135] The binder may be present in an amount of about 1 weight percent to about 10 weight percent, based on the dry weight of the homogenized tobacco material, preferably in an amount of about 2 weight percent to about 5 weight percent, based on the dry weight of the homogenized tobacco material.

[0136] The homogenized tobacco material may further include one or more lipids to enhance the diffusion rate of volatile components (e.g., aerosol formers, gingerols, and nicotine), where the lipids are included in the homogenized tobacco material during manufacture as described herein. Suitable lipids for inclusion within the homogenized tobacco material include, but are not limited to, medium chain triglycerides, cocoa butter, palm oil, palm kernel oil, mango oil, shea butter, soybean oil, cottonseed oil, coconut oil, hydrogenated coconut oil, candellila wax, carnauba wax, shellac, sunflower wax, sunflower oil, rice bran, and Revel A, and combinations thereof.

[0137] The homogenized tobacco material may further include a pH modifier.

[0138] The homogenized tobacco material may further include fibers to alter the mechanical properties of the homogenized tobacco material, and the fibers are included within the homogenized tobacco material during manufacture as described herein. Suitable exogenous fibers for inclusion in the homogenized tobacco material are known in the art and include fibers formed from non-tobacco and non-ginger materials, including, but not limited to, cellulose fibers, soft wood fibers, hard wood fibers, jute fibers, and combinations thereof. Exogenous fibers derived from tobacco and / or ginger may also be added. Any fibers added to the homogenized tobacco material are not considered to form part of the "particulate plant material" as defined above. Prior to inclusion within the homogenized tobacco material, the fibers may be treated by any suitable process known in the art, including, but not limited to, mechanical pulping, refining, chemical pulping, bleaching, sulfate pulping, and combinations thereof. Typically, the fibers have a length greater than their width.

[0139] Suitable fibers are typically greater than 400 micrometers and have a length of 4 millimeters or less, with lengths in the range of 0.7 millimeters to 4 millimeters being preferred. The fibers are preferably present in an amount of about 2 weight percent to about 15 weight percent, most preferably about 4 weight percent, based on the dry weight of the substrate.

[0140] In the context of the present invention, the aerosol generating element further comprises one or more aerosol formers. Upon volatilization, the aerosol formers can carry other vaporized compounds, such as nicotine and flavorants in the aerosol, which are released from the aerosol generating element upon heating. Aerosol formers suitable for inclusion in the aerosol generating element are known in the art and include, but are not limited to, polyhydric alcohols (such as triethylene glycol, propylene glycol, 1,3-butanediol and glycerol), esters of polyhydric alcohols (such as glycerol mono-, di- or triacetate), and aliphatic esters of mono-, di- or polycarboxylic acids (such as dimethyl dodecanedioate and tetradecanedioate).

[0141] The aerosol-generating components may include two or more of homogenized tobacco material, tobacco cast leaves, and reconstituted tobacco.

[0142] As an example, the aerosol-generating element may include a sheet of homogenized tobacco material produced from a blend of high-quality tobacco leaf materials, with the aerosol former being intimately combined with the tobacco leaf material prior to forming the sheet from the resulting mixture. Such homogenized tobacco material may be tobacco cast leaf, or reconstituted tobacco, or a combination of both. The tobacco cast leaf or reconstituted tobacco, or both, may be, for example, standard cast leaf or standard reconstituted tobacco, including but not limited to, recovered tobacco particles formed from tobacco particles, with the standard cast leaf or standard reconstituted tobacco being impregnated with the aerosol former after being formed into a sheet.

[0143] The inventors have found that these tobacco materials may have different aerosol delivery profiles when heated under the same conditions for the same period of time. In particular, standard tobacco cast leaf may tend to release aerosol species more quickly and at a lower temperature compared to standard reconstituted tobacco. Standard reconstituted tobacco may then tend to release aerosol species more quickly and at a lower temperature compared to the homogenized tobacco material described above. Thus, by adjusting the relative proportions of these different tobacco materials in the aerosol-generating element, it is advantageously possible to fine-tune the timing and intensity of aerosol delivery from the aerosol-generating element during use.

[0144] The aerosol-generating component may have an aerosol former content of about 5 percent to about 30 percent by weight on a dry weight basis.

[0145] Preferably, the aerosol-generating component has an aerosol former content of at least about 10 weight percent on a dry weight basis, more preferably at least about 15 weight percent on a dry weight basis.

[0146] The aerosol-generating components preferably have an aerosol former content of about 25 weight percent or less on a dry weight basis, more preferably about 20 weight percent or less on a dry weight basis.

[0147] The aerosol-generating components may have an aerosol former content of from 5 to 25 percent by weight on a dry weight basis, preferably from 10 to 25 percent by weight on a dry weight basis, more preferably from 15 to 25 percent by weight on a dry weight basis.The aerosol-generating components may have an aerosol former content of from 5 to 20 percent by weight on a dry weight basis, preferably from 10 to 20 percent by weight on a dry weight basis, more preferably from 15 to 20 percent by weight on a dry weight basis.

[0148] The aerosol-generating element may have an aerosol former content of about 30 percent to about 45 percent by weight. This relatively high level of aerosol former is particularly suitable for aerosol-generating elements intended to be heated at temperatures below 275 degrees Celsius. The aerosol-generating element preferably comprises about 2 percent to about 10 percent by weight of the cellulose ether, on a dry weight basis, and about 5 percent to about 50 percent by weight of the additional cellulose, on a dry weight basis. The use of a combination of the cellulose ether and the additional cellulose has been found to provide particularly effective aerosol delivery when used in an aerosol-generating substrate having an aerosol former content of 30 percent to 45 percent by weight.

[0149] Suitable cellulose ethers include, but are not limited to, methyl cellulose, hydroxypropyl methyl cellulose, ethyl cellulose, hydroxyl ethyl cellulose, hydroxyl propyl cellulose, ethyl hydroxyl ethyl cellulose and carboxymethyl cellulose (CMC). The cellulose ether may be carboxymethyl cellulose.

[0150] As used herein, the term "additional cellulose" encompasses any cellulose material incorporated into the homogenized tobacco material that is not derived from non-tobacco plant particles or tobacco particles provided in the homogenized tobacco material. Thus, the additional cellulose is incorporated into the homogenized tobacco material as an individual and separate cellulose source to any cellulose essentially provided within the non-tobacco plant particles or tobacco particles, in addition to the non-tobacco plant materials or tobacco materials. The additional cellulose is typically derived from a plant different from the non-tobacco plant particles or tobacco particles. Preferably, the additional cellulose is in the form of an inert cellulose material, which is sensorily inert and therefore does not substantially affect the sensory properties of the aerosol generated from the aerosol-generating substrate. For example, the additional cellulose is preferably a tasteless and odorless material.

[0151] The additional cellulose may include cellulose powder, cellulose fibers, or a combination thereof.

[0152] The aerosol former may act as a wetting agent on the aerosol-generating element or substrate.

[0153] The aerosol-generating element may include a plug of a porous substrate.

[0154] The term "porous substrate" is used herein to describe a material that provides a plurality of pores or openings that allow the passage of air through the material. The porous substrate can be any suitable porous material that is capable of holding or retaining the aerosol-generating medium or flavorant, particularly when these are provided in liquid or gel form, as described below.

[0155] An advantage of a porous substrate loaded with an aerosol-generating medium or flavor is that the aerosol-generating medium or flavor is retained within the porous medium, which may aid in the manufacture, storage, or transportation of the gel composition. This is particularly effective when the aerosol-generating medium or flavor is in the form of a gel, since the use of a porous substrate may aid in preserving and maintaining the gel in a desired core location, particularly during use, but also during manufacture and transportation.

[0156] The porous substrate may comprise natural, synthetic, or semi-synthetic materials, or a combination thereof. The porous substrate may comprise sheet materials, foams, or fibers, such as loose fibers, or a combination thereof. The porous substrate may comprise woven, nonwoven, or extruded materials, or a combination thereof. The porous substrate preferably comprises cotton, paper, viscose, PLA, or cellulose acetate, or a combination thereof. The porous substrate may comprise an assembly of sheet materials, for example made of cotton or cellulose acetate.

[0157] The aerosol-generating medium may include a liquid or gel impregnated into a porous substrate.

[0158] The aerosol-generating medium may comprise a gel comprising an alkaloid compound, an aerosol former, and at least one gelling agent.

[0159] The term "alkaloid compound" refers to any one of a class of naturally occurring organic compounds that contain one or more basic nitrogen atoms. Generally, alkaloids contain at least one nitrogen atom in an amine-type structure. This nitrogen atom or another nitrogen atom in the molecule of an alkaloid compound can be active as a base in an acid-base reaction. Most alkaloid compounds have one or more of their nitrogen atoms as part of a ring system, such as a heterocycle. In nature, alkaloid compounds are found primarily in plants, and are particularly common in certain families of flowering plants. However, some alkaloid compounds are found in animal species and fungi. In this disclosure, the term "alkaloid compound" refers to both naturally occurring and synthetically produced alkaloid compounds.

[0160] The gel may preferably include an alkaloid compound selected from the group consisting of nicotine, anatabine, and combinations thereof.

[0161] Preferably, the gel contains nicotine.

[0162] The term "nicotine" refers to nicotine and nicotine derivatives, such as free base nicotine, nicotine salts, and the like.

[0163] The gel preferably contains about 0.5 weight percent to about 10 weight percent of the alkaloid compound. The gel may contain about 0.5 weight percent to about 5 weight percent of the alkaloid compound. The gel preferably contains about 1 weight percent to about 3 weight percent of the alkaloid compound. The gel may preferably contain about 1.5 weight percent to about 2.5 weight percent of the alkaloid compound. The gel may preferably contain about 2 weight percent of the alkaloid compound.

[0164] The alkaloid compound component of the gel may be the most volatile component of the gel. The gel may contain water, which may be the most volatile component of the gel, and the alkaloid compound component of the gel may be the second most volatile component of the gel.

[0165] Preferably, nicotine is included in the gel. Nicotine may be added to the gel composition in its free base form or in its salt form.

[0166] The gel comprises from about 0.5 weight percent to about 10 weight percent nicotine, or from about 0.5 weight percent to about 5 weight percent nicotine. Preferably, the gel comprises from about 1 weight percent to about 3 weight percent nicotine, or from about 1.5 weight percent to about 2.5 weight percent nicotine, or about 2 weight percent nicotine.

[0167] As briefly mentioned above, the gel preferably further comprises an aerosol former. Ideally, the aerosol former is substantially resistant to thermal degradation at the operating temperature of the associated aerosol generating device. Suitable aerosol formers include, but are not limited to, polyhydric alcohols (such as triethylene glycol, 1,3-butanediol, glycerin, etc.), esters of polyhydric alcohols (such as glycerol monoacetate, diacetate, or triacetate), and aliphatic esters of mono-, di-, or polycarboxylic acids (such as dimethyl dodecanedioate, dimethyl tetradecanedioate, etc.). The polyhydric alcohol or mixtures thereof may be one or more of triethylene glycol, 1,3-butanediol, and glycerin (glycerol or propane-1,2,3-triol) or polyethylene glycol. The aerosol former is preferably glycerol.

[0168] The gel may comprise a majority of the aerosol former. The gel may comprise a mixture of water and aerosol former, with the aerosol former forming a majority (by weight) of the gel. The aerosol former may form at least about 50 percent by weight of the gel. The aerosol former may form at least about 60 percent by weight of the gel, or at least about 65 percent by weight, or at least about 70 percent by weight of the gel. The aerosol former may form about 70 percent to about 80 percent by weight of the gel. The aerosol former may form about 70 percent to about 75 percent by weight of the gel.

[0169] The gel may comprise a majority of glycerol. The gel may comprise a mixture of water and glycerol, with the glycerol forming a majority (by weight) of the gel. The glycerol may form at least about 50 percent by weight of the gel. The glycerol may form at least about 60 percent by weight, or at least about 65 percent by weight, or at least about 70 percent by weight of the gel. The glycerol may form about 70 percent to about 80 percent by weight of the gel. The glycerol may form about 70 percent to about 75 percent by weight of the gel.

[0170] Preferably, the gel further comprises at least one gelling agent. Preferably, the gel composition comprises a total amount of gelling agents in the range of about 0.4 weight percent to about 10 weight percent. More preferably, the gel comprises a gelling agent in the range of about 0.5 weight percent to about 8 weight percent. More preferably, the gel comprises a gelling agent in the range of about 1 weight percent to about 6 weight percent. More preferably, the gel comprises a gelling agent in the range of about 2 weight percent to about 4 weight percent. More preferably, the gel comprises a gelling agent in the range of about 2 weight percent to about 3 weight percent.

[0171] The term "gelling agent" refers to a compound that, when homogeneously added in an amount of about 0.3 weight percent to a 50 weight percent water / 50 weight percent glycerol mixture, leads to the formation of a solid medium or support matrix leading to a gel. Gelling agents include, but are not limited to, hydrogen bond cross-linking gelling agents and ionic cross-linking gelling agents.

[0172] The gelling agent may comprise one or more biopolymers. The biopolymers may be formed from polysaccharides.

[0173] Biopolymers include, for example, gellan gum (preferably native gellan gum, low acyl gellan gum, high acyl gellan gum, low acyl gellan gum), xanthan gum, alginate (alginic acid), agar, guar gum, etc. It may be preferred that the composition comprises xanthan gum. The composition may comprise two biopolymers. The composition may comprise three biopolymers. The composition may comprise two biopolymers in substantially equal amounts by weight. The composition may comprise three biopolymers in substantially equal amounts by weight.

[0174] Preferably, the gel comprises at least about 0.2 weight percent of the hydrogen bond crosslinked gelling agent. The gel preferably comprises at least about 0.2 weight percent of the ionic crosslinked gelling agent. Most preferably, the gel comprises at least about 0.2 weight percent of the hydrogen bond crosslinked gelling agent and at least about 0.2 weight percent of the ionic crosslinked gelling agent. The gel may comprise from about 0.5 weight percent to about 3 weight percent of the hydrogen bond crosslinked gelling agent and from about 0.5 weight percent to about 3 weight percent of the ionic crosslinked gelling agent, or from about 1 weight percent to about 2 weight percent of the hydrogen bond crosslinked gelling agent and from about 1 weight percent to about 2 weight percent of the ionic crosslinked gelling agent. The hydrogen bond crosslinked gelling agent and the ionic crosslinked gelling agent may be present in the gel in substantially equal amounts by weight.

[0175] The term "hydrogen bond cross-linking gelator" refers to a gelator that forms non-covalent or physical cross-links via hydrogen bonds. Hydrogen bonds are not covalent bonds to hydrogen atoms, but are a type of electrostatic dipole-dipole attraction between molecules. It results from the attraction between a hydrogen atom covalently bonded to an extremely electronegative atom, such as an N, O, or F atom, and another extremely electronegative atom.

[0176] The hydrogen-bond cross-linking gelling agent may comprise one or more of galactomannan, gelatin, agarose, or konjac gum, or agar. It may be preferred that the hydrogen-bond cross-linking gelling agent comprises agar.

[0177] The gel preferably contains the hydrogen-bond cross-linking gelling agent in the range of about 0.3 weight percent to about 5 weight percent. Preferably, the gel contains the hydrogen-bond cross-linking gelling agent in the range of about 0.5 weight percent to about 3 weight percent. Preferably, the gel contains the hydrogen-bond cross-linking gelling agent in the range of about 1 weight percent to about 2 weight percent.

[0178] The gel may contain galactomannan in the range of about 0.2 weight percent to about 5 weight percent. Preferably, the galactomannan may be in the range of about 0.5 weight percent to about 3 weight percent. Preferably, the galactomannan may be in the range of about 0.5 weight percent to about 2 weight percent. Preferably, the galactomannan may be in the range of about 1 weight percent to about 2 weight percent.

[0179] The gel may contain gelatin in the range of about 0.2 weight percent to about 5 weight percent. Preferably, the gelatin may be in the range of about 0.5 weight percent to about 3 weight percent. Preferably, the gelatin may be in the range of about 0.5 weight percent to about 2 weight percent. Preferably, the gelatin may be in the range of about 1 weight percent to about 2 weight percent.

[0180] The gel may contain agarose in the range of about 0.2 weight percent to about 5 weight percent. Preferably, the agarose may be in the range of about 0.5 weight percent to about 3 weight percent. Preferably, the agarose may be in the range of about 0.5 weight percent to about 2 weight percent. Preferably, the agarose may be in the range of about 1 weight percent to about 2 weight percent.

[0181] The gel may contain konjac gum in the range of about 0.2 weight percent to about 5 weight percent. Preferably, the konjac gum may be in the range of about 0.5 weight percent to about 3 weight percent. Preferably, the konjac gum may be in the range of about 0.5 weight percent to about 2 weight percent. Preferably, the konjac gum may be in the range of about 1 weight percent to about 2 weight percent.

[0182] The gel may contain agar in the range of about 0.2 weight percent to about 5 weight percent. Preferably, the agar may be in the range of about 0.5 weight percent to about 3 weight percent. Preferably, the agar may be in the range of about 0.5 weight percent to about 2 weight percent. Preferably, the agar may be in the range of about 1 weight percent to about 2 weight percent.

[0183] The term "ionically cross-linking gelator" refers to a gelator that forms non-covalent or physical cross-links through ionic bonds. Ionic cross-linking involves the association of polymer chains through non-covalent interactions. A cross-linked network is formed when multivalent molecules with opposite charges are electrostatically attracted to each other, giving rise to a cross-linked polymer network.

[0184] The ionic cross-linking gelling agent may include low acyl gellan, pectin, kappa carrageenan, iota carrageenan or alginate. Preferably, the ionic cross-linking gelling agent may include low acyl gellan.

[0185] The gel may contain an ionically cross-linking gelling agent in the range of about 0.3 weight percent to about 5 weight percent. Preferably, the gel contains an ionically cross-linking gelling agent in the range of about 0.5 weight percent to about 3 weight percent. Preferably, the gel contains an ionically cross-linking gelling agent in the range of about 1 weight percent to about 2 weight percent.

[0186] The gel may contain low acyl gellan in the range of about 0.2 weight percent to about 5 weight percent. Preferably, the low acyl gellan may be in the range of about 0.5 weight percent to about 3 weight percent. Preferably, the low acyl gellan may be in the range of about 0.5 weight percent to about 2 weight percent. Preferably, the low acyl gellan may be in the range of about 1 weight percent to about 2 weight percent.

[0187] The gel may contain pectin in the range of about 0.2 weight percent to about 5 weight percent. Preferably, the pectin may be in the range of about 0.5 weight percent to about 3 weight percent. Preferably, the pectin may be in the range of about 0.5 weight percent to about 2 weight percent. Preferably, the pectin may be in the range of about 1 weight percent to about 2 weight percent.

[0188] The gel may include kappa carrageenan in the range of about 0.2 weight percent to about 5 weight percent. Preferably, the kappa carrageenan may be in the range of about 0.5 weight percent to about 3 weight percent. Preferably, the kappa carrageenan may be in the range of about 0.5 weight percent to about 2 weight percent. Preferably, the kappa carrageenan may be in the range of about 1 weight percent to about 2 weight percent.

[0189] The gel may contain iota carrageenan in the range of about 0.2 weight percent to about 5 weight percent. Preferably, the iota carrageenan may be in the range of about 0.5 weight percent to about 3 weight percent. Preferably, the iota carrageenan may be in the range of about 0.5 weight percent to about 2 weight percent. Preferably, the iota carrageenan may be in the range of about 1 weight percent to about 2 weight percent.

[0190] The gel may contain alginate in the range of about 0.2 weight percent to about 5 weight percent. Preferably, the alginate may be in the range of about 0.5 weight percent to about 3 weight percent. Preferably, the alginate may be in the range of about 0.5 weight percent to about 2 weight percent. Preferably, the alginate may be in the range of about 1 weight percent to about 2 weight percent.

[0191] The gel may contain a hydrogen-bond cross-linking gelling agent and an ionic cross-linking gelling agent in a ratio of about 3:1 to about 1:3. Preferably, the gel may contain a hydrogen-bond cross-linking gelling agent and an ionic cross-linking gelling agent in a ratio of about 2:1 to about 1:2. Preferably, the gel may contain a hydrogen-bond cross-linking gelling agent and an ionic cross-linking gelling agent in a ratio of about 1:1.

[0192] The gel may further comprise a thickening agent. The thickening agent in combination with the hydrogen bond crosslinking gelling agent and the ionic crosslinking gelling agent surprisingly appears to support a solid medium and maintain the gel composition even when the gel composition contains high levels of glycerol.

[0193] The term "thickening agent" refers to a compound that, when uniformly added in an amount of 0.3 weight percent into a 50 weight percent water / 50 weight percent glycerol mixture at 25° C., increases the viscosity without resulting in the formation of a gel, and the mixture remains in a fluid state or remains fluid. Preferably, the thickening agent, when uniformly added in an amount of 0.3 weight percent into a 50 weight percent water / 50 weight percent glycerol mixture at 25° C., increases the viscosity by 0.1 s without resulting in the formation of a gel. -1Preferably, the thickener is a compound that, when homogeneously added in an amount of 0.3 weight percent to a 50 weight percent water / 50 weight percent glycerol mixture at 25° C., increases the viscosity by 0.1 s without causing the formation of a gel, preferably increases the viscosity by at least 50 cPs, preferably increases the viscosity by at least 200 cPs, preferably increases the viscosity by at least 500 cPs, preferably increases the viscosity by at least 1000 cPs, and the mixture remains in a fluid state or remains fluid, at a shear rate of 0.1 s without causing the formation of a gel. -1 "fluid" refers to a compound that increases the viscosity of a mixture at a shear rate of at least 2 times, at least 5 times, at least 10 times, or at least 100 times greater than before its addition and that causes the mixture to remain in a fluid state or to remain fluid.

[0194] The viscosity values ​​listed herein may be measured using a Brookfield RVT viscometer with a disk type RV#2 spindle rotating at 25° C. and a speed of 6 revolutions per minute (rpm).

[0195] The gel preferably comprises a thickening agent in the range of about 0.2 weight percent to about 5 weight percent. Preferably, the gel comprises a thickening agent in the range of about 0.5 weight percent to about 3 weight percent. Preferably, the gel comprises a thickening agent in the range of about 0.5 weight percent to about 2 weight percent. Preferably, the gel comprises a thickening agent in the range of about 1 weight percent to about 2 weight percent.

[0196] The thickening agent may include one or more of xanthan gum, carboxymethylcellulose, microcrystalline cellulose, methylcellulose, gum arabic, guar gum, lambda carrageenan, or starch. Preferably, the thickening agent may include xanthan gum.

[0197] The gel may contain xanthan gum in the range of about 0.2 weight percent to about 5 weight percent. Preferably, the xanthan gum may be in the range of about 0.5 weight percent to about 3 weight percent. Preferably, the xanthan gum may be in the range of about 0.5 weight percent to about 2 weight percent. Preferably, the xanthan gum may be in the range of about 1 weight percent to about 2 weight percent.

[0198] The gel may contain carboxymethylcellulose in the range of about 0.2 weight percent to about 5 weight percent. Preferably, the carboxymethylcellulose may be in the range of about 0.5 weight percent to about 3 weight percent. Preferably, the carboxymethylcellulose may be in the range of about 0.5 weight percent to about 2 weight percent. Preferably, the carboxymethylcellulose may be in the range of about 1 weight percent to about 2 weight percent.

[0199] The gel may contain microcrystalline cellulose in the range of about 0.2 weight percent to about 5 weight percent. Preferably, the microcrystalline cellulose may be in the range of about 0.5 weight percent to about 3 weight percent. Preferably, the microcrystalline cellulose may be in the range of about 0.5 weight percent to about 2 weight percent. Preferably, the microcrystalline cellulose may be in the range of about 1 weight percent to about 2 weight percent.

[0200] The gel may contain methylcellulose in the range of about 0.2 weight percent to about 5 weight percent. Preferably, the methylcellulose may be in the range of about 0.5 weight percent to about 3 weight percent. Preferably, the methylcellulose may be in the range of about 0.5 weight percent to about 2 weight percent. Preferably, the methylcellulose may be in the range of about 1 weight percent to about 2 weight percent.

[0201] The gel may contain gum arabic in the range of about 0.2 weight percent to about 5 weight percent. Preferably, the gum arabic may be in the range of about 0.5 weight percent to about 3 weight percent. Preferably, the gum arabic may be in the range of about 0.5 weight percent to about 2 weight percent. Preferably, the gum arabic may be in the range of about 1 weight percent to about 2 weight percent.

[0202] The gel may contain guar gum in the range of about 0.2 weight percent to about 5 weight percent. Preferably, the guar gum may be in the range of about 0.5 weight percent to about 3 weight percent. Preferably, the guar gum may be in the range of about 0.5 weight percent to about 2 weight percent. Preferably, the guar gum may be in the range of about 1 weight percent to about 2 weight percent.

[0203] The gel may include lambda carrageenan in the range of about 0.2 weight percent to about 5 weight percent. Preferably, the lambda carrageenan may be in the range of about 0.5 weight percent to about 3 weight percent. Preferably, the lambda carrageenan may be in the range of about 0.5 weight percent to about 2 weight percent. Preferably, the lambda carrageenan may be in the range of about 1 weight percent to about 2 weight percent.

[0204] The gel may contain starch in the range of about 0.2 weight percent to about 5 weight percent. Preferably, the starch may be in the range of about 0.5 weight percent to about 3 weight percent. Preferably, the starch may be in the range of about 0.5 weight percent to about 2 weight percent. Preferably, the starch may be in the range of about 1 weight percent to about 2 weight percent.

[0205] The gel may further comprise a divalent cation. Preferably, the divalent cation comprises calcium ions, such as calcium lactate in solution. The divalent cation (such as calcium ions) may aid in gel formation in compositions that include a gelling agent, such as an ionically cross-linking gelling agent. Ionic effects may aid in gel formation. The divalent cation may be present in the gel composition in a range of about 0.1 to about 1 weight percent, or about 0.5 to about 1 weight percent.

[0206] The gel may further comprise an acid. The acid may comprise a carboxylic acid. The carboxylic acid may comprise a ketone group. Preferably, the carboxylic acid may comprise a ketone group having less than about 10 carbon atoms, such as levulinic acid or lactic acid, or less than about 6 carbon atoms or less than about 4 carbon atoms. Preferably, the carboxylic acid has three carbon atoms (such as lactic acid). Lactic acid surprisingly improves the stability of the gel over similar carboxylic acids. The carboxylic acid may aid in gel formation. The carboxylic acid may reduce the change in the concentration of alkaloid compounds in the gel during storage. The carboxylic acid may reduce the change in the concentration of nicotine in the gel during storage.

[0207] The gel may include a carboxylic acid in the range of about 0.1 weight percent to about 5 weight percent. Preferably, the carboxylic acid may be in the range of about 0.5 weight percent to about 3 weight percent. Preferably, the carboxylic acid may be in the range of about 0.5 weight percent to about 2 weight percent. Preferably, the carboxylic acid may be in the range of about 1 weight percent to about 2 weight percent.

[0208] The gel may contain lactic acid in the range of about 0.1 weight percent to about 5 weight percent. Preferably, the lactic acid may be in the range of about 0.5 weight percent to about 3 weight percent. Preferably, the lactic acid may be in the range of about 0.5 weight percent to about 2 weight percent. Preferably, the lactic acid may be in the range of about 1 weight percent to about 2 weight percent.

[0209] The gel may contain levulinic acid in the range of about 0.1 weight percent to about 5 weight percent. Preferably, the levulinic acid may be in the range of about 0.5 weight percent to about 3 weight percent. Preferably, the levulinic acid may be in the range of about 0.5 weight percent to about 2 weight percent. Preferably, the levulinic acid may be in the range of about 1 weight percent to about 2 weight percent.

[0210] The gel preferably contains some water. If the composition contains some water, the gel is more stable. The gel preferably contains at least about 1 weight percent, or at least about 2 weight percent, or at least about 5 weight percent water. The gel preferably contains at least about 10 weight percent, or at least about 15 weight percent water.

[0211] The gel preferably contains about 8 weight percent to about 32 weight percent water. The gel preferably contains about 15 weight percent to about 25 weight percent water. The gel preferably contains about 18 weight percent to about 22 weight percent water. The gel preferably contains about 20 weight percent water.

[0212] An aerosol-generating article according to the present invention may comprise an aerosol-generating rod as described above and may further comprise a downstream section located downstream of the aerosol-generating rod, the aerosol-generating article comprising or consisting of a first plug segment, an aerosol-generating element and a second plug segment as described above. An aerosol-generating article according to the present invention may comprise an upstream section located upstream of the aerosol-generating rod.

[0213] The downstream section may include one or more downstream elements.

[0214] The downstream section may include a support element disposed in alignment with and downstream of the aerosol-generation rod, in particular the support element may be located immediately downstream of the aerosol-generation rod and may abut the aerosol-generation rod.

[0215] 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)). The support element may be formed from cellulose acetate. Other suitable materials include polyhydroxyalkanoate (PHA) fibers.

[0216] The support element may comprise a hollow tubular segment.The support element may comprise a hollow cellulose acetate tube.

[0217] The support element may be disposed substantially in alignment with the aerosol-generating rod, meaning that the length dimension of the support element is disposed approximately parallel to the longitudinal axis of the rod and article, for example within ±10 degrees of parallel to the longitudinal axis of the rod. The support element may extend along the longitudinal axis of the rod.

[0218] The support element preferably has an outer diameter approximately equal to the outer diameter of the aerosol-generating rod.

[0219] 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.

[0220] The support elements may have a length of about 5 millimeters to about 15 millimeters. Preferably, the support elements have a length of at least about 6 millimeters, and more preferably at least about 7 millimeters. The support elements may have a length of less than about 12 millimeters, and more preferably less than about 10 millimeters.

[0221] The support element may have a length of about 5 mm to about 15 mm, preferably about 6 mm to about 15 mm, and more preferably about 7 mm to about 15 mm. The support element may have a length 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. The support element may have a length 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.

[0222] The support element may have a length of about 8 millimeters.

[0223] Preferably, the hollow tubular segment of the support element is adapted to generate an RTD of approximately 0 millimeters of H2O (about 0 Pa) to approximately 20 millimeters of H2O (about 100 Pa), more preferably approximately 0 millimeters of H2O (about 0 Pa) to approximately 10 millimeters of H2O (about 100 Pa). Thus, the support element preferably does not contribute to the overall RTD of the aerosol-generating article.

[0224] The downstream section of the aerosol-generating article may include a mouthpiece element positioned downstream of and longitudinally aligned with the aerosol-generating rod.

[0225] The mouthpiece element is preferably located at the downstream or mouth end of the aerosol-generating article and extends all the way to the mouth end of the aerosol-generating article.

[0226] Preferably, the mouthpiece element comprises at least one mouthpiece filter segment of 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 comprises a cellulose acetate filter segment formed from cellulose acetate tow.

[0227] The mouthpiece element may consist of a single mouthpiece filter segment. The mouthpiece element may include two or more mouthpiece filter segments axially aligned in abutting end-to-end relationship with one another.

[0228] The downstream section may comprise an oral end cavity at a downstream end downstream of the mouthpiece element as described above. The oral end cavity may be defined by a hollow tubular element provided at the downstream end of the mouthpiece. The oral end cavity may be defined by an outer wrapper of the mouthpiece element, the outer wrapper extending in a downstream direction from the mouthpiece element.

[0229] The mouthpiece element may optionally include a flavorant, which may be provided in any suitable form, for example, the mouthpiece element may include one or more capsules, beads or granules of flavorant, or one or more flavor-loaded threads or filaments.

[0230] The downstream section of the aerosol-generating article may further include both a support element located immediately downstream of the aerosol-generating rod, and a mouthpiece element located downstream of the support element.

[0231] Preferably, the mouthpiece element has a low particle filtration efficiency.

[0232] Preferably, the mouthpiece is formed from a segment of fibrous filtration material.

[0233] The mouthpiece element is preferably surrounded by a plug wrap. The mouthpiece element is preferably non-ventilated so that air does not enter the aerosol-generating article along the mouthpiece element.

[0234] The mouthpiece element is preferably connected to one or more of the adjacent upstream components of the aerosol-generating article by a leading wrapper.

[0235] Preferably, the mouthpiece elements have an RTD of less than about 25 millimeters HO. More preferably, the mouthpiece elements have an RTD of less than about 20 millimeters HO. Even more preferably, the mouthpiece elements have an RTD of less than about 15 millimeters HO.

[0236] RTD values ​​of about 10 millimeters HO to about 15 millimeters HO are particularly preferred, as a mouthpiece element having one such RTD is expected to contribute minimally to the overall RTD of the aerosol-generating article and therefore provide substantially no filtering effect on the aerosol delivered to the user.

[0237] The mouthpiece element preferably has an outer diameter approximately equal to the outer diameter of the aerosol-generating article.

[0238] The mouthpiece element preferably has a length of at least about 5 millimeters, more preferably at least about 8 millimeters, more preferably at least about 10 millimeters. The mouthpiece element may preferably have a length of less than about 25 millimeters, more preferably less than about 20 millimeters, more preferably less than about 15 millimeters.

[0239] The mouthpiece element preferably has a length of about 5 mm to about 25 mm, more preferably about 8 mm to about 25 mm, and even more preferably about 10 mm to about 25 mm. The mouthpiece element preferably has a length of about 5 mm to about 10 mm, more preferably about 8 mm to about 20 mm, and even more preferably about 10 mm to about 20 mm. The mouthpiece element preferably has a length of about 5 mm to about 15 mm, more preferably about 8 mm to about 15 mm, and even more preferably about 10 mm to about 15 mm.

[0240] For example, the mouthpiece element 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. The mouthpiece element may have a length of approximately 12 millimeters.

[0241] The downstream section may further comprise an aerosol cooling element located downstream of the support element, the mouthpiece element being located downstream of both the support element and the aerosol cooling element. Particularly preferably, the mouthpiece element is located immediately downstream of the aerosol cooling element. As an example, the mouthpiece element may abut the downstream end of the aerosol cooling element.

[0242] The aerosol cooling element may define multiple longitudinally extending channels, for example to create a high surface area available for heat exchange. The multiple longitudinally extending channels may be defined by a sheet material that is pleated, assembled, or folded to form the channels. The multiple longitudinally extending channels may be defined by a single sheet that is pleated, assembled, or folded to form the channels. The sheet may also be crimped before being pleated, assembled, or folded. The multiple longitudinally extending channels may be defined by multiple sheets that are crimped, pleated, assembled, or folded to form the channels. The multiple longitudinally extending channels may be defined by multiple sheets that are crimped, pleated, assembled, or folded, i.e., two or more sheets that are brought into an overlay arrangement and then crimped, pleated, assembled, or folded as one.

[0243] One such additional aerosol cooling element may have a total surface area of ​​about 300 square millimeters per millimeter of length to about 1000 square millimeters per millimeter of length.

[0244] One such aerosol cooling element preferably provides a low draw resistance to the passage of air through the additional cooling element. Preferably, the aerosol cooling element does not substantially affect the draw resistance of the aerosol-generating article. The aerosol cooling element preferably comprises a sheet material selected from the group consisting of metal foil, polymer sheet, and substantially non-porous paper or cardboard. The aerosol cooling element may comprise a sheet material selected from the group consisting of polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polyethylene terephthalate (PET), polylactic acid (PLA), cellulose acetate (CA) and aluminum foil. The additional cooling element comprises a sheet of PLA.

[0245] The aerosol-generating article further comprises an upstream section at a location upstream of the aerosol-generating element. The upstream section may comprise one or more upstream elements. The upstream section may comprise an upstream element disposed immediately upstream of the aerosol-generating element.

[0246] The upstream element may 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 information about the brand, flavor, content, or details of the aerosol-generating device with which the article is intended to be used.

[0247] The upstream element may be a porous plug element. Preferably, the porous plug element does not alter the resistance to withdrawal 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 longitudinal porosity of the upstream element is defined as 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.

[0248] 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 over the cross section of the upstream element.

[0249] The porosity or permeability of the upstream element may be advantageously varied to provide a desired overall withdrawal resistance of the aerosol-generating article.

[0250] 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. The RTD of the upstream element may be at least about 20 millimeters of H2O.

[0251] The RTD of the upstream element is preferably less than or equal to about 80 millimeters of H2O. More preferably, the RTD of the upstream element is less than or equal to about 60 millimeters of H2O. Even more preferably, the RTD of the upstream element is less than or equal to about 40 millimeters of H2O.

[0252] The RTD of the upstream element may be about 5 millimeters H2O to about 80 millimeters H2O, preferably about 10 millimeters H2O to about 80 millimeters H2O, more preferably about 15 millimeters H2O to about 80 millimeters H2O, and even more preferably about 20 millimeters H2O to about 80 millimeters H2O. The RTD of the upstream element may be about 5 millimeters H2O to about 60 millimeters H2O, preferably about 10 millimeters H2O to about 60 millimeters H2O, more preferably about 15 millimeters H2O to about 60 millimeters H2O, and even more preferably about 20 millimeters H2O to about 60 millimeters H2O. The RTD of the upstream element may be about 5 millimeters H2O to about 40 millimeters H2O, preferably about 10 millimeters H2O to about 40 millimeters H2O, more preferably about 15 millimeters H2O to about 40 millimeters H2O, and even more preferably about 20 millimeters H2O to about 40 millimeters H2O.

[0253] The upstream element may be formed from a material that is impermeable to air. The aerosol-generating article may be configured to allow air to enter the aerosol-generating rod through suitable vent means provided in the wrapper.

[0254] The upstream element may be made of any material suitable for use in an aerosol-generating article. The upstream element may be made of the same material as that used 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.

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

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

[0257] The upstream element preferably 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. The upstream element may have a length of about 5 millimeters. The length of the upstream element may be advantageously varied to provide a desired overall length of 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 may be increased to maintain the same overall length of the article.

[0258] 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, have no discernible symmetry.

[0259] 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, which provides structural rigidity to the upstream element.

[0260] The aerosol-generating article may have a length of from about 35 millimeters to about 100 millimeters.

[0261] The aerosol-generating article may have a length of from about 35 millimeters to about 100 millimeters.

[0262] Preferably, the overall length of an aerosol-generating article according to the invention is at least about 38 millimeters. More preferably, the overall length of an aerosol-generating article according to the invention is at least about 40 millimeters. Even more preferably, the overall length of an aerosol-generating article according to the invention is at least about 42 millimeters.

[0263] Preferably, the overall length of an aerosol-generating article according to the invention is 70 mm or less. More preferably, the overall length of an aerosol-generating article according to the invention is 60 mm or less. Even more preferably, the overall length of an aerosol-generating article according to the invention is 50 mm or less.

[0264] The total length of the aerosol-generating article is preferably about 38 mm to about 70 mm, more preferably about 40 mm to about 70 mm, and even more preferably about 42 mm to about 70 mm. The total length of the aerosol-generating article is preferably about 38 mm to about 60 mm, more preferably about 40 mm to about 60 mm, and even more preferably about 42 mm to about 60 mm. The total length of the aerosol-generating article is preferably about 38 mm to about 50 mm, more preferably about 40 mm to about 50 mm, and even more preferably about 42 mm to about 50 mm. The total length of the aerosol-generating article may be about 45 mm.

[0265] 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.

[0266] 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.

[0267] The aerosol-generating article may have an outer diameter of about 5 mm to about 12 mm, preferably about 6 mm to about 12 mm, more preferably about 7 mm to about 12 mm. The aerosol-generating article may have an outer diameter of about 5 mm to about 10 mm, preferably about 6 mm to about 10 mm, more preferably about 7 mm to about 10 mm. The aerosol-generating article may have an outer diameter of about 5 mm to about 8 mm, preferably about 6 mm to about 8 mm, more preferably about 7 mm to about 8 mm.

[0268] An aerosol-generating article according to the invention comprises, in a linear continuous arrangement, an upstream element, an aerosol-generating rod located immediately downstream of the upstream element, a support element located immediately downstream of the aerosol-generating element, a mouthpiece element located immediately downstream of the support element, and an outer wrapper surrounding the upstream element, aerosol-generating element, support element, and mouthpiece element.

[0269] More particularly, the aerosol generation rod may abut the upstream element. The support element may abut the aerosol generation rod. The aerosol cooling element may abut the support element. The mouthpiece element may abut the aerosol cooling element.

[0270] The aerosol-generating article has a substantially cylindrical shape and an outer diameter of about 7.25 millimeters.

[0271] The upstream element has a length of about 9 millimeters, the aerosol-generating element has a length of about 12 millimeters, the support element has a length of about 18 millimeters, and the mouthpiece element has a length of about 8 millimeters. Thus, the overall length of the aerosol-generating article is about 47 millimeters.

[0272] The upstream element is in the form of a plug of cellulose acetate encased in stiff plug wrap.

[0273] The aerosol-generating rod comprises, in a linear sequential arrangement, a second aerosol-generating segment comprising a plug of porous substrate and the aerosol-generating gel described above provided in a core portion of the plug, a first aerosol-generating segment comprising an assembly of sheets of homogenized tobacco material, and a non-aerosol-generating segment comprising a plug of porous substrate.

[0274] The mouthpiece is in the form of a low density cellulose acetate filter segment.

[0275] The aerosol-generating rod and article according to the invention can be used in an aerosol-generating device comprising a heater for heating the rod or article. The present invention therefore also relates to an aerosol-generating system comprising one such aerosol-generating device, e.g. an electrically heated aerosol-generating device, and an aerosol-generating article comprising the aerosol-generating rod described above. Examples of suitable aerosol-generating devices are known to those skilled in the art. In general, a suitable aerosol-generating device comprises a heating chamber for receiving at least one aerosol-generating article and a heater adapted to heat the at least one aerosol-generating article when received in the chamber.

[0276] This includes, but is not limited to, aerosol generators that include one or more induction heaters disposed about the exterior surface of a tubular susceptor element that defines a heating chamber, although aerosol generators with other types of external heater elements may also be suitable.

[0277] The aerosol-generating article preferably includes a susceptor element, which may be located within or surround the aerosol-generating element.

[0278] As discussed above, the present disclosure also relates to an aerosol generation system comprising an aerosol generating device having a distal end and an oral end. The aerosol generating device comprises a body. The body or housing of the aerosol generating device may define a device cavity for removably receiving an aerosol-generating article at the oral end of the device. The aerosol generating device comprises a heating element or heater for heating the aerosol-generating substrate when the aerosol-generating article is received within the device cavity.

[0279] The device cavity may be referred to as the heating chamber of the aerosol-generating device. The device cavity may extend between a distal end and an oral or proximal end. The distal end of the device cavity may be a closed end, and the oral or proximal end of the device cavity may be an open end. The aerosol-generating article may be inserted into the device cavity or heating chamber through the open end of the device cavity. The device cavity may be cylindrical in shape to fit the same shape of the aerosol-generating article.

[0280] The phrase "received within" may refer to the fact that a component or element is fully or partially received within another component or element. For example, the phrase "an aerosol-generating article is received within a device cavity" refers to the aerosol-generating article being fully or partially received within a device cavity of the aerosol-generating article. When the aerosol-generating article is received within the device cavity, the aerosol-generating article may abut a distal end of the device cavity. When the aerosol-generating article is received within the device cavity, the aerosol-generating article may be substantially proximate to the distal end of the device cavity. The distal end of the device cavity may be defined by an end wall.

[0281] The diameter of the device cavity may be the same as or larger than the diameter of the aerosol-generating article. The diameter of the device cavity may be the same as the diameter of the aerosol-generating article to establish a tight fit with the aerosol-generating article.

[0282] The device cavity may be configured to establish a tight fit with an aerosol-generating article received within the device cavity. A tight fit may refer to a sliding fit. The aerosol-generating device may include a peripheral wall. Such a peripheral wall may define the device cavity, or the heating chamber. The peripheral wall defining the device cavity may be configured to engage in a tight fit with an aerosol-generating article received within the device cavity such that, when received within the device, there is substantially no gap or empty space between the peripheral wall defining the device cavity and the aerosol-generating article.

[0283] Such an airtight fit may establish an airtight fit or configuration between the device cavity and the aerosol-generating article received therein.

[0284] In such an airtight configuration, there will be substantially no gaps or empty spaces between the peripheral walls defining the device cavity and the aerosol-generating article for air to flow therethrough.

[0285] A tight fit with the aerosol-generating article may be established along the entire length of the device cavity or along a portion of the length of the device cavity.

[0286] The aerosol generating device may include an airflow channel extending between the channel inlet and the channel outlet. The airflow channel may be configured to establish fluid communication between an interior of the device cavity and an exterior of the aerosol generating device. The airflow channel of the aerosol generating device may be defined within a housing of the aerosol generating device to allow fluid communication between an interior of the device cavity and an exterior of the aerosol generating device. When an aerosol-generating article is received within the device cavity, the airflow channel may be configured to provide air flowing into the article for delivery of generated aerosol to a user who draws from a mouth end of the article.

[0287] The airflow channel of the aerosol generating device may be defined within or by the peripheral wall of the housing of the aerosol generating device. In other words, the airflow channel of the aerosol generating device may be defined within the thickness of the peripheral wall, or by the inner surface of the peripheral wall, or a combination of both. The airflow channel may be partially defined by the inner surface of the peripheral wall, or partially defined within the thickness of the peripheral wall. The inner surface of the peripheral wall defines the periphery of the device cavity.

[0288] The airflow channel of the aerosol generating device may extend from an inlet located at the oral or proximal end of the aerosol generating device to an outlet located away from the oral end of the device. The airflow channel may extend along a direction parallel to the longitudinal axis of the aerosol generating device.

[0289] The aerosol generating device may include an elongated heater (or heating element) arranged for insertion into the aerosol generating article when the aerosol generating article is housed within the device cavity. The elongated heater may be arranged with the device cavity. The elongated heater may extend into the device cavity. Additional heating arrangements are discussed further below.

[0290] The heater can be any suitable type of heater. Preferably, the heater is an external heater.

[0291] Preferably, the heater, when housed within the aerosol generating device, is capable of externally heating the aerosol-generating article. Such an external heater may surround the aerosol-generating article when inserted or received within the aerosol generating device.

[0292] The heater may be arranged to heat the outer surface of the aerosol-forming substrate. The heater may be arranged to be inserted into the aerosol-forming substrate when the aerosol-forming substrate is received in the cavity. The heater may be located within the device cavity or heating chamber.

[0293] The heater may comprise at least one heating element. The at least one heating element may be any suitable type of heating element. The device may comprise only one heating element. The device may comprise multiple heating elements. The heater may include at least one resistive heating element. The heater preferably comprises multiple resistive heating elements. The resistive heating elements are preferably electrically connected in a parallel arrangement. Advantageously, providing multiple resistive heating elements electrically connected in a parallel arrangement may facilitate delivery of desired power to the heater while reducing or minimizing the voltage required to provide the desired power. Advantageously, reducing or minimizing the voltage required to operate the heater may facilitate reducing or minimizing the physical size of the power supply.

[0294] Suitable materials for forming the at least one resistive heating element include, but are not limited to, semiconductors such as doped ceramics, "conductive" ceramics (such as, for example, molybdenum disilicide), carbon, graphite, metals, metal alloys, and composites made of ceramic and metallic materials. Such composites may include doped or undoped ceramics. Examples of suitable doped ceramics include doped silicon carbide. Examples of suitable metals include titanium, zirconium, tantalum, and platinum group metals. Examples of suitable metal alloys include stainless steel, nickel-containing, cobalt-containing, chromium-containing, aluminum-containing, titanium-containing, zirconium-containing, hafnium-containing, niobium-containing, molybdenum-containing, tantalum-containing, tungsten-containing, tin-containing, gallium-containing, manganese-containing, and iron-containing alloys, as well as nickel-, iron-, cobalt-, and stainless steel-based superalloys, Timetal®, and iron-manganese-aluminum-based alloys.

[0295] The at least one resistive heating element may include one or more stamped pieces of electrically resistive material, such as stainless steel. The at least one resistive heating element may include a heating wire or filament (e.g., Ni-Cr (nickel-chromium), platinum, tungsten, or alloy wire).

[0296] The at least one heating element may include an electrically insulating substrate and the at least one resistive heating element may be provided on the electrically insulating substrate.

[0297] The electrically insulating substrate may comprise any suitable material. For example, the electrically insulating substrate may comprise one or more of paper, glass, ceramic, anodized metal, coated metal, and polyimide. The ceramic may comprise mica, alumina (Al2O3), or zirconia (ZrO2). The electrically insulating substrate preferably has a thermal conductivity of about 40 watts per meter Kelvin or less, preferably about 20 watts per meter Kelvin or less, and ideally about 2 watts per meter Kelvin or less.

[0298] The heater may comprise a heating element comprising a rigid, electrically insulating substrate having one or more conductive tracks or wires arranged on its surface. Depending on the size and shape of the electrically insulating substrate, it may be possible to insert the heater directly into the aerosol-forming substrate. If the electrically insulating substrate is not sufficiently rigid, the heating element may comprise further reinforcing means. An electric current may be passed through the one or more conductive tracks to heat the heating element and the aerosol-forming substrate.

[0299] The heater may include an induction heating arrangement. The induction heating arrangement may comprise an inductor coil and a power source configured to provide a high frequency oscillating current to the inductor coil. As used herein, high frequency oscillating current means an oscillating current having a frequency of about 500 kHz to about 30 MHz. The heater may advantageously comprise a DC / AC inverter for converting a DC current provided by a DC power source to an alternating current. The inductor coil may be arranged to generate a high frequency oscillating electromagnetic field upon receiving the high frequency oscillating current from the power source. The inductor coil may be arranged to generate a high frequency oscillating electromagnetic field within the device cavity. The inductor coil may substantially surround the device cavity. The inductor coil may be located within the device cavity and may be arranged to surround the aerosol-generating article when received therein. The inductor coil may extend at least partially along a length of the device cavity.

[0300] The heater may include an induction heating element. The induction heating element may be a susceptor element. As used herein, the term "susceptor element" refers to an element that includes a material capable of converting electromagnetic energy into heat. When the susceptor element is located within an alternating electromagnetic field, the susceptor is heated. Heating of the susceptor element may be the result of at least one of hysteresis losses and eddy currents induced in the susceptor, depending on the electrical and magnetic properties of the susceptor material.

[0301] The susceptor element may be arranged such that when an aerosol-generating article is received within the cavity of the aerosol generating device, the oscillating electromagnetic field generated by the inductor coil induces a current in the susceptor element, heating the susceptor element. The aerosol generating device is preferably capable of generating a fluctuating electromagnetic field having a magnetic field strength (H-field strength) of 1-5 kiloamperes per meter (kA / m), preferably 2-3 kA / m, for example about 2.5 kA / m. The electrically operated aerosol generating device is preferably capable of generating a fluctuating electromagnetic field having a frequency of 1-30 MHz, for example 1-10 MHz, for example 5-7 MHz.

[0302] The susceptor element may be located within the aerosol-generating article. The susceptor element is preferably located in contact with the aerosol-forming substrate. The susceptor element may be located on or within the aerosol-forming substrate.

[0303] The susceptor element may be located within the aerosol-generating device. The susceptor element may be located within the cavity. The aerosol-generating device may include only one susceptor element. The aerosol-generating device may comprise multiple susceptor elements.

[0304] The susceptor element may be arranged to heat an outer surface of the aerosol-forming substrate. The susceptor element may be arranged to be inserted into the aerosol-forming substrate when the aerosol-forming substrate is received within the cavity.

[0305] The susceptor elements may comprise any suitable material. The susceptor elements may be formed from any material that can be inductively heated to a temperature sufficient to release volatile compounds from the aerosol-forming substrate. Suitable materials for the elongated susceptor elements include graphite, molybdenum, silicon carbide, stainless steel, niobium, aluminum, nickel, nickel-containing compounds, titanium, and composites of metallic materials. Some susceptor elements comprise metal or carbon. Advantageously, the susceptor elements may comprise or consist of ferromagnetic materials, such as ferritic iron, ferromagnetic steel or stainless steel, ferromagnetic alloys, ferromagnetic particles, and ferrites. Suitable susceptor elements may be or include aluminum. The susceptor elements preferably comprise more than about 5 percent, preferably more than about 20 percent, more preferably more than about 50 percent or more than about 90 percent ferromagnetic or paramagnetic materials. Some elongated susceptor elements may be heated to temperatures greater than about 250 degrees Celsius.

[0306] The susceptor element may comprise a non-metallic core having a metallic layer disposed thereon. For example, the susceptor element may include a ceramic core or a metallic track formed on the outer surface of the substrate.

[0307] The susceptor element may include a susceptor sleeve for heating the aerosol-generating article, preferably the aerosol-generating element. The susceptor element may define a chamber for receiving the aerosol-generating article. The susceptor element may surround at least a portion of the aerosol-generating article when the article is received within the susceptor element. The susceptor element may surround at least the aerosol-generating element or the substrate when the article is received within the susceptor element. The susceptor element may include a tube. The susceptor element may include a tube having a partially or fully porous wall. One or more inductor coils are mounted around the susceptor element or the sleeve. A pair of inductor coils are mounted around the susceptor element or the sleeve. The aerosol-generating article may not include an internal susceptor.

[0308] The aerosol generating device may comprise at least one resistive heating element and at least one inductive heating element.The aerosol generating device may comprise a combination of resistive and inductive heating elements.

[0309] The aerosol generating system may also include a mouthpiece element or tube that can be connected to the aerosol generating device or aerosol generating article. The mouthpiece element may include or be made of a hollow tube of cardboard, plastic, polymeric or paper material. The mouthpiece element may be made of a biodegradable material. When inserting one or more aerosol generating articles or rods into the aerosol generating device, the aerosol generating article or rod may not be disposed for the user to directly puff thereon, especially when the aerosol generating article only includes the aerosol generating rod and does not include any mouthpiece filter or downstream section. Instead, the user may connect or couple a separate mouthpiece element to either the downstream end of the aerosol generating rod exposed at the open end of the device cavity or the open proximal end of the device cavity. Such a mouthpiece element or tube may guide the generated aerosol to the user.

[0310] The aerosol generating system may comprise a plurality of aerosol generating articles, with the heating device or aerosol generating device being arranged to receive one or more of the plurality of aerosol generating articles. As mentioned above, the heating device may be arranged to receive at least two aerosol generating articles simultaneously. A user may insert different relatively short aerosol generating rods or articles, each having a different type of aerosol generating element, into the heating device or aerosol generating device to beneficially modify the final aerosol generated or entrained in the air flowing through the different aerosol generating rods. The aerosol generating device may comprise one heater, or two or more heaters, one heater for each aerosol generating article that the device is arranged to receive.

[0311] The present invention is defined in the claims. However, below is provided a non-exhaustive list of non-limiting examples. Any one or more of the features of these examples may be combined with any one or more features of any other example, embodiment, or aspect described herein.

[0312] The invention will be further described in the following sections with reference to the drawings in the accompanying drawings. [Brief description of the drawings]

[0313] [Figure 1] FIG. 1 shows a schematic side perspective view of a partially unrolled aerosol-generating article according to an embodiment of the invention. [Diagram 2] FIG. 2 shows a schematic side perspective view of another partially unrolled aerosol-generating article in accordance with an alternative embodiment of the invention. [Diagram 3] FIG. 3 shows a schematic cross-sectional side view of another aerosol-generating article in accordance with an alternative embodiment of the present invention. [Figure 4] FIG. 4 shows a schematic cross-sectional side view of another aerosol-generating article according to an alternative embodiment of the invention. [Diagram 5] FIG. 5 shows a schematic cross-sectional side view of an aerosol generation system according to the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0314] Example 1. 1. An aerosol-generating article for generating an inhalable aerosol upon heating, the aerosol-generating article comprising: A first segment; a second segment, the second segment being transparent; and an aerosol-generating element positioned between the first segment and the second segment, the second segment being located downstream of the aerosol-generating element; An aerosol-generating article comprising: a first segment, an aerosol-generating element, and a wrapper surrounding the second segment, wherein a portion of the wrapper surrounding the aerosol-generating element is air permeable such that the wrapper establishes fluid communication between an exterior of the aerosol-generating article and the aerosol-generating element. Example 2. The aerosol-generating article according to example 1, wherein the first segment is a first plug segment. Example 3. An aerosol-generating article according to example 1 or 2, wherein the second segment is a second plug segment. Example 4. An aerosol-generating article according to any of Examples 1 to 3, wherein the aerosol-generating element is located downstream of the first segment. Example 5. An aerosol-generating article according to any of Examples 1 to 4, wherein the aerosol-generating element is located immediately downstream of the first segment. Example 6. An aerosol-generating article according to any of Examples 1 to 5, wherein the second segment is located immediately downstream of the aerosol-generating element. Example 7. An aerosol-generating article according to any of Examples 1-6, wherein the aerosol-generating element is positioned immediately between the first segment and the second segment. Example 8. An aerosol-generating article according to any one of Examples 1 to 7, wherein the first segment is a first filter segment. Example 9. An aerosol-generating article according to any one of Examples 1 to 8, wherein the second segment is a second filter segment. Example 10. An aerosol-generating article according to any of Examples 1 to 9, wherein the air permeability of the permeable portion of the wrapper is at least 2500 Coresta units. Example 11. An aerosol-generating article according to any of Examples 1 to 10, wherein the air permeability of the permeable portion of the wrapper is at least 5000 Coresta units. Example 12. An aerosol-generating article according to any of Examples 1-11, wherein at least 50 percent of a portion of the wrapper surrounding the aerosol-generating element is air permeable. Example 13. An aerosol-generating article according to any of Examples 1-12, wherein the wrapper has a basis weight of at least 10 grams per square meter (gsm). Example 14. An aerosol-generating article according to any one of Examples 1 to 10, wherein the air permeability of the permeable portion of the wrapper is at least 2500 Coresta units, preferably at least 5000 Coresta units, and at least 50 percent of the portion of the wrapper surrounding the aerosol-generating element is air permeable. Example 15. An aerosol-generating article according to any of Examples 1-14, wherein an entire portion of the wrapper surrounding the aerosol-generating element is air permeable. Example 16. An aerosol-generating article according to any of Examples 1-15, wherein the aerosol-generating element is visible through the wrapper. Example 17. An aerosol-generating article according to any of Examples 1 to 16, wherein a portion of the wrapper surrounding the aerosol-generating element is translucent or transparent. Example 18. An aerosol-generating article according to Example 17, wherein a portion of the wrapper surrounding the aerosol-generating element has a light transmittance of at least 40 percent, preferably at least 50 percent. Example 19. An aerosol-generating article according to any of Examples 1-18, wherein the first plug segment is impermeable. Example 20. An aerosol-generating article according to any one of Examples 1-17, wherein the first plug segment is permeable. Example 21. The aerosol-generating article according to Example 20, wherein the resistance to withdrawal (RTD) per unit length of the first plug segment is from about 0 mmH2O per mm to about 3 mmH2O per mm. Example 22. An aerosol-generating article according to any of Examples 1-21, wherein the RTD per unit length of the second plug segment is from about 0 mmH2O per mm to about 3 mmH2O per mm. Example 23. An aerosol-generating article according to any one of Examples 1 to 22, further comprising a susceptor element, the susceptor element being located within or surrounding the aerosol-generating element. Example 24. An aerosol-generating article according to any one of Examples 1 to 23, wherein the aerosol-generating element comprises a tobacco material and an aerosol former. Example 25. 25. The aerosol-generating article according to example 24, wherein the tobacco material comprises one or more of homogenized tobacco material, tobacco cast leaf, and reconstituted tobacco. Example 26. An aerosol-generating article according to any one of Examples 1 to 25, wherein the aerosol-generating element comprises a non-tobacco plant material. Example 27. An aerosol-generating article according to any one of Examples 1 to 23, wherein the aerosol-generating element comprises a porous substrate impregnated with a liquid or gel. Example 28. 28. The aerosol-generating article according to example 27, wherein the gel comprises an alkaloid compound, an aerosol former, and at least one gelling agent. Example 29. An aerosol-generating article according to any of Examples 1-28, wherein the wrapper is impregnated with a flavorant. Example 30. An aerosol-generating article according to any one of Examples 1 to 29, wherein the length of the first plug segment or the second plug segment is between 2 millimeters and 10 millimeters. Example 31. An aerosol-generating article according to any one of Examples 1 to 30, wherein the length of the aerosol-generating element is between 5 millimeters and 25 millimeters. Example 32. An aerosol generating system comprising an aerosol-generating article according to any one of Examples 1 to 31, and a heating device arranged to receive the aerosol-generating article. Example 33. 33. An aerosol generating system according to example 32, wherein the heating device is configured to externally heat the aerosol-generating article when received within the aerosol generating device. Example 34. An aerosol generation system according to example 32 or 33, further comprising a mouthpiece element connectable to an aerosol generating device or an aerosol generating article. Example 35. An aerosol generating system according to any one of Examples 32 to 34, comprising a plurality of aerosol generating articles, each of which is according to any one of Examples 1 to 31, and a heating device arranged to receive one or more of the plurality of aerosol generating articles. Example 36. An aerosol generating system according to Example 35, wherein the heating device is arranged to receive one aerosol generating article, or two aerosol generating articles simultaneously.

[0315] An embodiment of an aerosol-generating article or rod 1 is shown in Figure 1. The aerosol-generating rod 1 comprises a first, upstream plug segment 2 and an aerosol-generating element 4 located immediately downstream of the first plug segment 2. A second, downstream plug segment 6 is located immediately downstream of the aerosol-generating element 4. In effect, the aerosol-generating element 4 is adjacent to the two plug segments 2, 6.

[0316] The first plug segment 2, the aerosol generating element 4, and the second plug segment 6 are axially aligned in a linear, continuous arrangement. The first plug segment 2 extends from the upstream end 3 of the aerosol generating rod 1 to the upstream end of the aerosol generating element 4, and the second plug segment 6 extends from the downstream end of the aerosol generating element 4 to the downstream end of the aerosol generating rod 1. The first plug segment 2, the aerosol generating element 4, and the second plug segment 6 abut one another.

[0317] The aerosol-generating rod 1 shown in Figures 1 and 2 comprises a wrapper 8 having a permeable portion or region 12. The wrapper 8 surrounds the first plug segment 2, the aerosol-generating element 4, and the second plug segment 6. The permeable portion 12 of the wrapper 8 is made from a tea bag material.

[0318] 1, the permeable portion 12 of the wrapper 8 extends along and over a portion of the wrapper 8 that overlaps or is disposed around the aerosol-generating element 4. The permeable region 12 is disposed to overlap the entire outer surface of the aerosol-generating element 4.

[0319] As shown in the alternative arrangement of FIG. 2, the permeable portion 12 occupies the entire surface area of ​​the wrapper 8 and is not limited to a particular region of the wrapper 8 .

[0320] The contents of the aerosol-generating rod 1 (at least the aerosol-generating element 4 ) are visible through the permeable portion 12 of the wrapper 8 .

[0321] The air permeability of the permeable portion 12 of the wrapper 8 is about 5000 Coresta units. The air permeability of the wrapper 8 is about 5000 Coresta units. The basis weight of the wrapper 8 is about 15 grams per square meter.

[0322] The aerosol-generating rod 1 includes a first plug segment that is non-porous or non-permeable so that air cannot enter the rod 1 through the upstream end 3. Air can only enter the aerosol-generating element 4 through the permeable portion 12 of the wrapper 8, as shown by arrow B. The generated aerosol then flows from the aerosol-generating element 4 through the second plug segment 6 and exits the aerosol-generating rod 1 at the downstream end 5, as shown by arrow C. Although arrow B is shown at the top of FIG. 3, air can enter the aerosol-generating rod 1 from any direction through the permeable portion 12. The RTD per unit length of the second plug segment is approximately 3 mmH2O per mm.

[0323] An alternative embodiment of an aerosol-generating rod 11 is shown in Figure 4, which differs from the aerosol-generating rod 1 shown in Figure 3 in that the first plug segment 22 is air permeable so as to allow air to enter the aerosol-generating rod 11 also through the upstream end 3, as indicated by arrow A. The RTD per unit length of the first plug segment is approximately 3 mmH2O per mm.

[0324] The first plug segment 2, 22 has a length of about 5 millimeters. The aerosol generating element or segment 4 has a length of about 10 millimeters. The second plug segment 6 has a length of about 5 millimeters. Thus, the aerosol generating rod 1, 11 has a total length of about 20 millimeters. The outer diameter of the aerosol generating rod 1, 11 is about 7.25 millimeters.

[0325] The first plug segment 22 and the second plug segment 6 are made from a permeable filter material, such as cellulose acetate tow. The aerosol-generating element 4 includes a tobacco material and an aerosol former. More specifically, the aerosol-generating element 4 includes an assembly of sheets of homogenized tobacco material. Alternatively, the aerosol-generating element 4 includes a porous substrate impregnated with a liquid or gel. The aerosol-generating element 4 preferably includes a susceptor element (not shown) located therein.

[0326] FIG. 5 shows a schematic representation of an electrically operated aerosol generating system 100 comprising an aerosol generating device 10, an aerosol generating rod or article 11, and a separate mouthpiece segment 18. FIG. 5 shows a downstream oral end portion of the aerosol generating device 10 in which a device cavity is defined and in which the aerosol generating article 10 can be received. The aerosol generating device 1 comprises a housing (or body) extending between an oral end and a distal end (not shown). The housing includes a peripheral wall 14. The peripheral wall 14 defines a device cavity for receiving the aerosol generating article 11. The device cavity is defined by a closed distal end and an open oral end. The oral end of the device cavity is located at the oral end of the aerosol generating device 10. The aerosol generating article 11 is configured to be received through the oral end of the device cavity.

[0327] The exemplary aerosol generating device 10 comprises an induction heater having one or more external inductor coils (not shown) for heating the aerosol-generating article 11, particularly the aerosol-generating element 4, and a susceptor sleeve 16. The susceptor sleeve 16 comprises a tube having a porous wall. The one or more inductor coils (not shown) are mounted around the susceptor sleeve 16 to define a cylindrical chamber for receiving the aerosol-generating article 11, as shown diagrammatically in FIG.

[0328] The aerosol generating device 10 is powered by a battery (not shown) and controlled by a control or electronic circuit (not shown). A user may connect a mouthpiece segment 18, which comprises a hollow tube of cardboard material, to the downstream end 5 of the aerosol generating rod 1, 11 to direct the aerosol generated upon puff into the user's mouth.

[0329] Of course, the aerosol-generating rods or articles 1, 11 described above may also be suitable for use with other aerosol-generating devices.

[0330] For the purposes of this specification and the appended claims, unless otherwise indicated, all numbers expressing amounts, quantities, percentages, and the like should be understood in all cases as modified by the term "about." Also, all ranges include the maximum and minimum points disclosed, and include any intermediate ranges therein, which may or may not be specifically recited herein. Thus, in this context, the number A is understood as A ± 10% of A. Within this context, the number A may be considered to include a numerical value that is within the general standard error for the measurement of the property that the number A modifies. The number A may deviate by the percentages recited above, in some cases as used in the appended claims, provided that the amount by which A deviates does not materially affect the basic and novel property(ies) of the claimed invention. Also, all ranges include the maximum and minimum points disclosed, and include any intermediate ranges therein, which may or may not be specifically recited herein.

Claims

1. 1. An aerosol-generating article for generating an inhalable aerosol upon heating, said aerosol-generating article comprising: a first plug segment including a cross section of a solid material; a second plug segment comprising a cross section of a solid material, said second plug segment being a filter plug segment and being permeable; an aerosol generating element positioned immediately between the first plug segment and the second plug segment, the second plug segment being located downstream from the aerosol generating element; and an aerosol-generating article comprising: a wrapper surrounding the first plug segment, the aerosol-generating element, and the second plug segment, a portion of the wrapper surrounding the aerosol-generating element being air permeable such that the wrapper establishes fluid communication between an exterior of the aerosol-generating article and the aerosol-generating element, the air permeability of the permeable portion of the wrapper being greater than 2,500 and less than 12,000 Coresta units.

2. 2. The aerosol-generating article of claim 1, wherein the air permeability of the permeable portion of the wrapper is at least 5000 Coresta units.

3. 3. The aerosol-generating article of claim 1, wherein the wrapper has a basis weight of at least 10 grams per square meter (gsm).

4. 4. The aerosol-generating article of claim 1, wherein at least 50 percent of the portion of the wrapper surrounding the aerosol-generating element is air permeable.

5. 5. The aerosol-generating article of claim 1, wherein the entire portion of the wrapper surrounding the aerosol-generating element is air permeable.

6. The aerosol-generating article of any preceding claim, wherein the aerosol-generating element is visible through the wrapper.

7. 7. The aerosol-generating article of claim 1, wherein the portion of the wrapper surrounding the aerosol-generating element is translucent or transparent.

8. 8. The aerosol-generating article of claim 7, wherein the portion of the wrapper surrounding the aerosol-generating element has a light transmittance of at least 40 percent, preferably at least 50 percent.

9. The aerosol-generating article of any one of claims 1 to 8, wherein the first plug segment is impermeable.

10. An aerosol-generating article according to any one of claims 1 to 8, wherein the first plug segment is permeable.

11. The resistance to withdrawal (RTD) per unit length of the first plug segment is about 0 mmH per mm. 2 Approximately 3 mmH per 0 mm 2 The aerosol-generating article of claim 10, wherein

12. The RTD per unit length of the second plug segment is about 0 mmH per mm. 2 Approximately 3 mmH per 0 mm 2 The aerosol-generating article according to any one of claims 1 to 11, wherein O is a

13. 13. An aerosol-generating article according to any preceding claim, wherein the length of each of the first and second plug segments is 5 mm or less.

14. 14. The aerosol-generating article of any one of claims 1 to 13, wherein the second plug segment is formed from a sheet of a cellulosic material, a polylactic acid-based material, a bioplastic material, or a material formed from paper, cardboard, or a polymer.

15. An aerosol-generating article according to any one of claims 1 to 13, and a heating device arranged to receive the aerosol-generating article, preferably 15. An aerosol generating system according to any preceding claim, wherein the heating device is configured to externally heat the aerosol-generating article when received within the heating device.

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