Aerosol generation system having an air inlet zone

Abstract

An aerosol-generating system (100) is provided, comprising an aerosol-generating article (1) and an aerosol-generating device (10). The aerosol-generating article comprises an aerosol-forming substrate rod (12) and a filter positioned downstream of the aerosol-forming substrate rod. The aerosol-forming substrate rod and filter are assembled within a wrapper (22). The aerosol-generating article comprises a first air entry zone (15) located on the wrapper. The first air entry zone is configured to allow air to enter the interior of the aerosol-generating article. The aerosol-generating device has a distal end and a mouth end (2). The aerosol-generating device comprises a housing (4). The housing defines a device cavity for removably receiving the aerosol-generating article at the mouth end of the device. The aerosol-generating device comprises a heater for heating the aerosol-forming substrate when the aerosol-generating article is received within the device cavity. The aerosol-generating device comprises an airflow channel (5) extending between a channel inlet (7) and a channel outlet (9). The airflow channel is configured to establish fluid communication between the interior of the device cavity and the exterior of the aerosol-generating device. The aerosol generation system is configured such that, when an aerosol-generating article is received within the device cavity, fluid communication between the interior of the aerosol-generating article and the exterior of the aerosol-generating device is established by fluid communication established between the first air entry zone of the aerosol-generating article received within the device cavity and the airflow channel of the aerosol-generating device.

Description

Technical Field

[0001] The present invention relates to an aerosol generation system comprising an aerosol generation device configured to receive an aerosol generating article.

Background Art

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

[0003] Numerous prior art documents disclose aerosol generation devices for consuming aerosol generating articles. Such devices include, for example, electrically heated aerosol generation devices in which an aerosol is generated by heat transfer from one or more electric heater elements of the aerosol generation device to the aerosol-forming substrate of a heated aerosol generating article.

[0004] Typically, an aerosol generating article is specifically adapted to be used in conjunction with a particular aerosol generating device, or the aerosol generating device is specifically adapted to be used in conjunction with a particular aerosol generating article. In particular, there may be cases where it is necessary not to use a particular aerosol generating article together with a particular aerosol generating device. This may be because such devices may overheat a particular aerosol generating article or may not heat other aerosol generating articles, and the particular article is suitable for being heated by the heating element of the particular aerosol generating device.

[0005] Accordingly, it is desirable to provide an aerosol generating system that prevents the use of an incompatible aerosol generating article with a particular aerosol generating device, or that prevents the use of an incompatible aerosol generating device with a particular aerosol generating article. Summary of the Invention

[0006] Disclosed herein is an aerosol generating system comprising an aerosol generating article and an aerosol generating device. The aerosol generating article comprises a rod of an aerosol forming substrate and a filter positioned downstream of the rod of the aerosol forming substrate. The rod and the filter of the aerosol forming substrate are assembled within a wrapper. The aerosol generating article comprises a first air inlet zone located on the wrapper. The first air inlet zone is configured to allow air to enter into the aerosol generating article. The aerosol generating device has a distal end and a mouthpiece end. The aerosol generating device comprises a housing. The housing defines a device cavity for removably receiving the aerosol generating article at the mouthpiece end of the device. The aerosol generating device comprises a heater for heating the aerosol forming substrate when the aerosol generating article is received within the device cavity. The aerosol generating device comprises an airflow channel extending between a channel inlet and a channel outlet. The airflow channel is configured to establish fluid communication between the interior of the device cavity and the exterior of the aerosol generating device. The aerosol generating system is configured such that when the aerosol generating article is received within the device cavity, fluid communication between the interior of the aerosol generating article and the exterior of the aerosol generating device is established by fluid communication established between the first air inlet zone of the aerosol generating article received within the device cavity and the airflow channel of the aerosol generating device.

[0007] Disclosed herein is an aerosol generating system comprising an aerosol generating article and an aerosol generating device. The aerosol generating article may comprise a rod of an aerosol-forming substrate. The aerosol generating article may comprise a filter positioned downstream of the rod of the aerosol-forming substrate. The rod of the aerosol-forming substrate may be assembled within a wrapper. The filter may be assembled within the wrapper. The aerosol generating article may comprise a first air inlet zone located on the wrapper. The first air inlet zone may be configured to allow air to enter the interior of the aerosol generating article. The aerosol generating device may have a distal end and a mouth end. The aerosol generating device may comprise a housing. The housing may define a device cavity for removably receiving the aerosol generating article at the mouth end of the device. The aerosol generating device may comprise a heater for heating the aerosol-forming substrate when the aerosol generating article is received within the device cavity. The aerosol generating device may comprise an air flow channel extending between a channel inlet and a channel outlet. The air flow channel may be configured to establish a fluid communication between the interior of the device cavity and the exterior of the aerosol generating device. The aerosol generating system may be configured such that when the aerosol generating article is received within the device cavity, a fluid communication between the interior of the aerosol generating article and the exterior of the aerosol generating device is established by a fluid communication established between the first air inlet zone of the aerosol generating article received within the device cavity and the air flow channel of the aerosol generating device.

[0008] As used herein, the downstream section may refer to one or more components located downstream of the rod of the aerosol-forming substrate. The filter may be a downstream section. The filter may form part of the downstream section. The downstream section may include the filter.

[0009] Disclosed herein is an aerosol generating system comprising an aerosol generating article and an aerosol generating device. The aerosol generating article may comprise a rod of an aerosol forming substrate. The aerosol generating article may comprise a downstream section positioned downstream of the rod of the aerosol forming substrate. The rod of the aerosol forming substrate may be assembled within a wrapper. The downstream section may be assembled within the wrapper. The aerosol generating article may comprise a first air inlet zone located on the wrapper. The first air inlet zone may be configured to allow air to enter the interior of the aerosol generating article. The aerosol generating device may have a distal end and a mouth end. The aerosol generating device may comprise a housing. The housing may define a device cavity for removably receiving the aerosol generating article at the mouth end of the device. The aerosol generating device may comprise a heater for heating the aerosol forming substrate when the aerosol generating article is received within the device cavity. The aerosol generating device may comprise an air flow channel extending between a channel inlet and a channel outlet. The air flow channel may be configured to establish fluid communication between the interior of the device cavity and the exterior of the aerosol generating device. The aerosol generating system may be configured such that when the aerosol generating article is received within the device cavity, fluid communication between the interior of the aerosol generating article and the exterior of the aerosol generating device is established by fluid communication established between the first air inlet zone of the aerosol generating article received within the device cavity and the air flow channel of the aerosol generating device.

[0010] The aerosol generating article may comprise an aerosol former. The aerosol forming substrate may have an aerosol former content of greater than about 10 percent on a dry weight basis.

[0011] The filter, or the downstream section, may include a hollow tubular segment. The hollow tubular segment may be positioned downstream of the rod of the aerosol forming substrate. The hollow tubular segment may be positioned immediately downstream of the rod of the aerosol forming substrate.

[0012] In the aerosol generating device of the present invention, in order to consume the aerosol generating article and generate an aerosol, it is necessary to establish a fluid communication between the inside of the aerosol generating article and the outside of the aerosol generating device. During consumption, the user can inhale the aerosol generating article so that the aerosol generated within the aerosol generating article can be experienced and consumed by the user. Through such a drawing operation, air flows from outside the aerosol generating device, through the aerosol generating device into the aerosol generating article, and can flow through the aerosol generating article to convey the aerosol generated within the article to the user's mouth.

[0013] By configuring the aerosol generation system such that the fluid communication between the inside of the aerosol generating article and the outside of the aerosol generating device is established by the fluid communication established between the first air entry zone of the aerosol generating article received within the device cavity and the airflow channel of the aerosol generating device, it is ensured that a compatible aerosol generating article is used together with the aerosol generating device. For use in the aerosol generation system of the present invention, a compatible aerosol generating article needs to have a first air entry zone configured such that a fluid communication is established between the first air entry zone of the aerosol generating article when received within the device cavity and the airflow channel of the aerosol generating device. Further, a compatible aerosol generating device needs to have an airflow channel configured to establish a fluid communication with the first air entry zone of the aerosol generating article received within the device.

[0014] Fluid communication between the interior of the aerosol generating article and the exterior of the aerosol generating device can be established by an airflow channel outlet of the aerosol generating device that covers or overlaps a first air inlet zone of the aerosol generating article received within the device cavity. Accordingly, a compatible aerosol generating article, when received within the device cavity, must have a first air inlet zone configured such that the airflow channel outlet of the aerosol generating device covers or overlaps the first air inlet zone of the aerosol generating article. Further, a compatible aerosol generating device must have an airflow channel configured such that the outlet covers or overlaps the first air inlet zone of the aerosol generating article when received within the device.

[0015] If an incompatible aerosol generating article is used with the aerosol generating device of the aerosol generation system of the present disclosure, the user may not be able to use the aerosol generation system and may not be able to consume or at least fully experience the incompatible aerosol generating article. Further, if a compatible aerosol generating article is used with a different aerosol generating device not belonging to the aerosol generation system of the present disclosure, the user may not be able to use the aerosol generation system and may not be able to consume or at least fully experience the compatible aerosol generating article. This is because if the alignment of the airflow channel outlet of the aerosol generating device and the first air inlet zone of the aerosol generating article does not occur, fluid communication between the interior of the aerosol generating article and the exterior of the aerosol generating device may not be properly or fully established.

[0016] Fluid communication between the exterior of the aerosol generating device and the interior of the aerosol generating article may be established by a partial or complete overlap or alignment between the outlet of the airflow channel of the device and the first air inlet zone of the article.

[0017] Fluid communication between the exterior of the aerosol generating device and the interior of the aerosol generating article may be established by partial or complete overlap or alignment between the airflow channel of the device and the first air entry zone of the article.

[0018] As used herein, the term "aerosol generating device" refers to a device comprising a heater element that interacts with an aerosol-forming substrate of an aerosol generating article to generate an aerosol.

[0019] As used herein, the term "longitudinal direction" refers to the direction corresponding to the main longitudinal axis of the aerosol generating article or device, extending between the upstream and downstream ends of the aerosol generating article or aerosol generating device.

[0020] As used herein, the terms "upstream" and "downstream" describe the relative position of an element or portion of an element of the aerosol generating article or device with respect to the direction in which the aerosol is conveyed through the aerosol generating article during use.

[0021] The term "mouth-side end" refers to the part of an element or component that is configured to be in or near the user's mouth during normal use of the element or component. The mouth-side end of a component may also correspond to the downstream end of the same component. For example, the mouth-side end of an aerosol generating article may also be the downstream end of the article. The mouth-side end of an aerosol generating article or device is configured to be placed in or near the consumer's mouth during normal use. The mouth-side end of an aerosol generating device may also be referred to as the proximal end of the aerosol generating device.

[0022] During use, air is mainly drawn longitudinally through the aerosol generating article. Outside the device, air may be drawn through the article via the upstream end.

[0023] The term "transverse direction" 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.

[0024] The term "length" means the dimension of a component of the aerosol-generating article or device in the major axis direction.

[0025] 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 so as to conform to the same shape of the aerosol-generating article.

[0026] The expression "received within" may refer to the fact that a component or element is received, either completely or partially, within another component or element. For example, the expression "the aerosol-generating article is received within the device cavity" refers to the fact that the aerosol-generating article is received, either completely or partially, within the device cavity of the aerosol-generating article. When the aerosol-generating article is received within the device cavity, the aerosol-generating article may abut against the distal end of the device cavity. When the aerosol-generating article is received within the device cavity, the aerosol-generating article may be substantially proximate to the distal end of the device cavity. The distal end of the device cavity may be defined by an end wall.

[0027] The length of the device cavity may be from about 10 mm to about 50 mm. The length of the device cavity may be from about 20 mm to about 40 mm. The length of the device cavity may be from about 25 mm to about 30 mm. The length of the device cavity may be the same as or longer than the length of the rod of the aerosol-forming substrate.

[0028] The diameter of the device cavity may be from about 4 mm to about 50 mm. The diameter of the device cavity may be from about 4 mm to about 30 mm. The diameter of the device cavity may be from about 5 mm to about 15 mm. The diameter of the device cavity may be from about 6 mm to about 12 mm. The diameter of the device cavity may be from about 7 mm to about 10 mm. The diameter of the device cavity may be from about 7 mm to about 8 mm.

[0029] 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 in order to establish a tight fit with the aerosol generating article.

[0030] The device cavity may be configured to establish a tight fit with the aerosol generating article received within the device cavity. A tight fit may refer to a sliding fit. The aerosol generating device may comprise 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 the aerosol generating article received within the device cavity such that there is substantially no gap or empty space between the peripheral wall defining the device cavity and the aerosol generating article when received within the device.

[0031] Such an airtight fit may establish an airtight fit or configuration between the device cavity and the aerosol generating article received therein. Such an airtight configuration may mean that air can only be drawn into the interior of the aerosol generating article through the alignment or overlap of the air flow channel outlet and the first air entry zone. In such an airtight configuration, there is substantially no gap or empty space between the peripheral wall defining the device cavity and the aerosol generating article through which air flows. Thus, if an incompatible aerosol generating article is used with the aerosol generating device, such alignment does not occur, and thus air may not be drawn through the incompatible aerosol generating article.

[0032] A tight fit with the aerosol-generating article can be established along the entire length of the device cavity or along a portion of the length of the device cavity. The tight fit can be established at a position downstream of the first air inlet zone of the aerosol-generating article. A portion of the peripheral wall configured to establish such a tight fit may be referred to as a sealing portion of the peripheral wall. Such a tight fit can be established when the airflow channel is defined within the thickness of the peripheral wall of the aerosol-generating device. The sealing portion of the peripheral wall may be defined along the entire length of the device cavity.

[0033] When the airflow channel is defined on the inner surface of the peripheral wall of the device housing, a portion of the peripheral wall between the airflow channel and the distal end of the device cavity may define a sealing portion of the peripheral wall. This ensures that air does not flow through the airflow channel towards the upstream end of the aerosol-generating article. A portion of the peripheral wall between the airflow channel and the distal end of the device cavity may form an airtight configuration with the upstream portion of the aerosol-generating article when received within the device.

[0034] The sealing portion of the peripheral wall may be configured to establish an airtight fit with a portion of the aerosol-generating article at a position downstream of the first air inlet zone of the aerosol-generating article. The sealing portion of the peripheral wall may be configured to establish an airtight fit with a portion of the aerosol-generating article at a position downstream of the second air inlet zone of the aerosol-generating article.

[0035] The diameter of the device cavity may vary along the longitudinal axis of the aerosol-generating device. The diameter of the device cavity may decrease from the distal end of the device cavity to the sealing portion of the peripheral wall.

[0036] The diameter of the device cavity may increase in a direction from the sealing portion of the peripheral wall towards the distal end of the device cavity. The diameter of the device cavity between the distal end and the sealing portion of the peripheral wall may be larger than the diameter of the remaining portion of the device cavity. The diameter of the device cavity may increase in a direction away from the sealing portion of the peripheral wall and in a direction away from the mouth-side end of the device.

[0037] By providing a diameter that is larger than other portions of the device cavity or a plurality of larger diameters to a portion of the device cavity, the device cavity, when received within the device, can define a gap or chamber around (surrounding) the upstream portion of the aerosol-generating article. In such embodiments, alignment or overlap between the first air inlet zone and the first outlet of the device's airflow channel may not be necessary to ensure fluid communication between the exterior of the device and the interior of the article. There is still a need to introduce air into the article through the first air inlet zone. Air flowing into the device cavity through the first outlet of the airflow channel can flow into such a gap or chamber and then be drawn into the article through the first air inlet zone. Such a gap or chamber provides a cushion of air around the said upstream portion of the article, which can either be heated by the device's heater or act as a cushion of cooling air surrounding the article.

[0038] The aerosol-generating device may comprise a peripheral wall defining the device cavity, and the aerosol-generating device may comprise an outer peripheral protrusion extending from the peripheral wall into the device cavity, the outer peripheral protrusion being configured to establish an airtight fit with a portion of the aerosol-generating article at a position downstream of the first air inlet zone of the aerosol-generating article when received within the aerosol-generating device.

[0039] The diameter of the device cavity may be larger than the diameter of the aerosol-generating article, and the inner diameter of the outer peripheral protrusion may be the same as the diameter of the aerosol-generating article such that a tight fit is established between the article and the outer peripheral protrusion after the article is received within the aerosol-generating device. The inner diameter of the outer peripheral protrusion may be smaller than the diameter of the aerosol-generating article. This can ensure that an airtight fit is more reliably established.

[0040] By establishing an airtight fit with the aerosol-generating article downstream of the first air inlet zone, it is further ensured that air can enter the interior of the aerosol-generating article only through the alignment of the airflow channel outlet and the first air inlet zone. This can be achieved by either the sealing portion of the peripheral wall or the outer peripheral protrusion, both of which are described above.

[0041] When the aerosol-generating article is received within the device cavity, the upstream end of the aerosol-generating article may be blocked so as to substantially prevent air from entering the aerosol-generating article through its upstream end. However, when the aerosol-generating article is not received within the aerosol-generating device, air may flow through the aerosol-generating article through its upstream end. When the article is received or inserted into the device, the upstream end of the aerosol-generating article may be around the distal end of the device cavity so that air can no longer flow through the upstream end of the article. Thus, the air flowing through the airflow channel can be drawn through the article only via the first air inlet zone. The upstream end of the aerosol-generating article may be defined by the upstream end of the rod of the aerosol-forming substrate.

[0042] The aerosol-generating device may comprise an airflow channel extending between a channel inlet and a channel outlet. The airflow channel may be configured to establish fluid communication between the interior of the device cavity and the exterior of the aerosol-generating device. The airflow channel of the aerosol-generating device may be defined within the housing of the aerosol-generating device to enable fluid communication between the interior of the device cavity and the exterior of the aerosol-generating device. When the aerosol-generating article is received within the device cavity, the airflow channel may be configured to provide air flowing into the article to deliver the generated aerosol to the user drawn from the mouth-side end of the article.

[0043] 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 by a combination of both. The airflow channel may be partially defined by the inner surface of the peripheral wall and may be partially defined within the thickness of the peripheral wall. The inner surface of the peripheral wall defines the periphery of the device cavity.

[0044] The airflow channel of the aerosol generating device may extend from an inlet located at the mouth-side end or proximal end of the aerosol generating device to an outlet located away from the mouth-side end of the device. The airflow channel may extend along a direction parallel to the longitudinal axis of the aerosol generating device. The outlet of the airflow channel is configured such that when a compatible aerosol generating article is received within the device cavity, the outlet covers the first air inlet zone of the article.

[0045] The airflow channel may be provided with two or more outlets, one for each air inlet zone provided in the article configured to be used with the aerosol generating device. For example, if the aerosol generating article comprises a first air inlet zone and a second air inlet zone, the airflow channel of the corresponding aerosol generating device may have at least one first outlet for covering the first air inlet zone and at least one second outlet for covering the second air inlet zone when the aerosol generating article is fully received within the aerosol generating device. Thus, the aerosol generating system may be configured such that when the aerosol generating article is received within the device cavity, the fluid communication between the interior of the aerosol generating article and the exterior of the aerosol generating device is established by the fluid communication established between the first and second air inlet zones of the aerosol generating article received within the device cavity and the airflow channel of the aerosol generating device.

[0046] When the airflow channel is defined within the peripheral wall of the device, the airflow channel may include a first portion that extends axially of the device from the channel inlet, and a second portion that extends transversely or radially from the end of the first portion in the direction of the channel outlet. As a result, the airflow channel may include a bend or elbow for connecting the inlet and outlet of the airflow channel. If the airflow channel includes two or more outlets along its length, the airflow channel may include additional channel portions that extend transversely from the first portion to each of the additional outlets. If the airflow channel includes a single outlet, the airflow channel may include an L-shaped bend or elbow.

[0047] When the airflow channel is defined by the inner surface of the peripheral wall, the length of the airflow channel may be directly exposed to the device cavity, i.e., the longitudinal side surfaces of the airflow channel may be open to the device cavity. The thickness of a portion of the peripheral wall that defines the airflow channel may be less than the thickness of the remaining portion of the peripheral wall. The diameter of a portion of the peripheral wall that defines the airflow channel may be greater than the diameter of the remaining portion of the peripheral wall. In such embodiments, the airflow channel may be in an annular shape such that the airflow channel surrounds the device cavity and the aerosol-generating article received within the device cavity.

[0048] In embodiments where the airflow channel is defined by the inner surface of the peripheral wall of the housing, the entire length of the airflow channel may be exposed or open to the device cavity and, therefore, to the aerosol-generating article received within the device. In such embodiments, the airflow channel is configured to cover all air inlet zones of a compatible aerosol-generating article in order to establish fluid communication between the exterior of the aerosol-generating device and the interior of the aerosol-generating article. In such embodiments, the outlet of the airflow channel may be considered the open side of the airflow channel, i.e., the side of the airflow channel that is exposed or open to the device cavity.

[0049] The length of the airflow channel may be less than the length of the device cavity. The length of the airflow channel refers to the longitudinal or axial distance along which the airflow channel extends.

[0050] The airflow channel may be configured such that a first outlet of the airflow channel is aligned with or covers a first air inlet zone of the aerosol-generating article received within the device cavity. The airflow channel may extend from a first inlet located at a mouth-side end of the housing of the aerosol-generating device to the first outlet. The first outlet, or any outlet, of the airflow channel may be provided between a distal end and a mouth-side end of the device cavity.

[0051] The first outlet may be located at least about 2 mm away from the distal end of the device cavity. The first outlet may be located at least about 3 mm away from the distal end of the device cavity. The first outlet may be located at least about 5 mm away from the distal end of the device cavity. The first outlet may be located at least about 7 mm away from the distal end of the device cavity.

[0052] The distance of the first outlet from the distal end of the device cavity and the distance of the first air inlet zone from the distal end of the device cavity when the article is received within the device cavity may be similar or the same. The distance of a further outlet of the airflow channel from the distal end of the device cavity and the distance of a further air inlet zone from the distal end of the device cavity when the article is received within the device cavity may be similar or the same. The distance of the distal end of the airflow channel from the distal end of the device cavity and the distance of the air inlet zone from the distal end of the device cavity when the article is received within the device cavity may be similar or the same.

[0053] The first outlet may be located at most about 25 mm away from the distal end of the device cavity. The first outlet may be located from about 3 mm to about 20 mm away from the distal end of the device cavity. The first outlet may be located from about 5 mm to about 18 mm away from the distal end of the device cavity. The first outlet may be located from about 7 mm to about 16 mm away from the distal end of the device cavity. The airflow channel may not extend beyond the distal end of the device cavity.

[0054] The length of the air flow channel may be about 23 mm. The length of the air flow channel may be from about 3 mm to about 100 mm. The length of the air flow channel may be from about 8 mm to about 70 mm. The length of the air flow channel may be from about 10 mm to about 50 mm. The length of the air flow channel may be from about 12 mm to about 40 mm. The length of the air flow channel may be from about 12 mm to about 40 mm. The length of the air flow channel may be from about 15 mm to about 30 mm. The length of the air flow channel may be from about 20 mm to about 25 mm.

[0055] When a compatible aerosol generating article comprises a first air entry zone located downstream of the rod of the aerosol forming substrate, the length of the air flow channel may be from about 8 mm to about 25 mm. The length of the air flow channel may be from about 10 mm to about 15 mm. The length of the air flow channel may be from about 11 mm to about 13 mm.

[0056] The diameter of the air flow channel may be from about 0.1 mm to about 5 mm. The diameter of the air flow channel may be from about 0.5 mm to about 4 mm. The diameter of the air flow channel may be from about 1 mm to about 3 mm. The diameter of the air flow channel may be from about 1.5 mm to about 2.5 mm. The diameter of the air flow channel and its outlet and inlet may be the same or different.

[0057] The "length" of the air flow channel may refer to how far the air flow channel extends in the long axis direction.

[0058] A plurality of air flow channels, each having at least one inlet and at least one outlet, may be provided within the aerosol generating device. Such a plurality of air flow channels may be evenly and circumferentially distributed around the device cavity.

[0059] The air flow channel, or each air flow channel, may include a single inlet and a plurality of outlets. In such embodiments, there may be one outlet corresponding to each air entry zone provided on the aerosol generating article configured to be received within the aerosol generating device.

[0060] As described above, the aerosol generating article according to the present invention comprises a rod and a filter of the aerosol forming substrate, or a downstream section located downstream of the rod of the aerosol forming substrate.

[0061] The aerosol generating article may further comprise an upstream section located upstream of the rod of the aerosol generating substrate. The upstream section may comprise one or more upstream elements. In some embodiments, the upstream section may include an upstream element disposed immediately upstream of the aerosol generating element. The upstream element may extend from the upstream end of the aerosol generating substrate to the upstream end of the aerosol generating article. The upstream element may abut against the upstream end of the aerosol generating article. The upstream element may be referred to as the upstream section. The aerosol generating article may comprise an air inlet at the upstream end of the aerosol generating article. When the aerosol generating article comprises an upstream element, the air inlet may be provided through the upstream element. Air entering through the air inlet may pass through the aerosol generating substrate to generate the main stream aerosol.

[0062] The porosity or permeability of the upstream section may advantageously vary in order to provide the desired overall draw resistance of the aerosol generating article.

[0063] In some embodiments, the upstream section may be formed of a material that is impermeable to air. In such embodiments, the aerosol generating article may be configured such that air flows into the rod of the aerosol generating substrate through suitable ventilation means provided within the wrapper.

[0064] The upstream section may be made of any material suitable for use in an aerosol generating article. For example, the upstream element may comprise a plug of material. Suitable materials for forming the upstream section include filter materials, ceramics, polymeric materials, cellulose acetate, cardboard, zeolites, or the aerosol generating substrate. The upstream section preferably comprises a plug containing cellulose acetate.

[0065] If the upstream section includes a plug of material, the downstream end of the plug of material may be around the upstream end of the aerosol-generating substrate. For example, the upstream section may include a plug including cellulose acetate that abuts the upstream end of the aerosol-generating substrate. This can advantageously help hold the aerosol-generating substrate in place.

[0066] If the upstream section includes a plug of material, the downstream end of the plug of material may be at a gap from the upstream end of the aerosol-generating substrate. The upstream element may include a plug including a fibrous filter material.

[0067] The upstream section may have a length of at least about 1 millimeter. For example, the upstream section may have a length of at least about 2 millimeters, at least about 4 millimeters, or at least about 6 millimeters.

[0068] The upstream section may have a length of about 15 millimeters or less. For example, the upstream section may have a length of about 12 millimeters or less, about 10 millimeters or less, or about 8 millimeters or less.

[0069] The upstream section may have a length of from about 1 millimeter to about 15 millimeters. For example, the upstream section may have a length of from about 2 millimeters to about 12 millimeters, from about 4 millimeters to about 10 millimeters, or from about 6 millimeters to about 8 millimeters.

[0070] The upstream section or element may include a hollow tubular segment.

[0071] The filter or downstream section may include a plug of filter material and a hollow tubular segment located between the rod of the aerosol-forming substrate and the mouthpiece segment. The three elements may all be aligned in the longitudinal axis. The rod of the aerosol-forming substrate may include at least the aerosol former. The hollow tubular segment may be a support segment or a cooling segment. The hollow tubular segment may be positioned immediately downstream of the aerosol-forming substrate or may be located.

[0072] The filter or downstream section may include a plug of filter material and an aerosol cooling segment (or element) located between the rod of the aerosol-forming substrate and the mouthpiece segment. The three elements may all be aligned in the longitudinal axis.

[0073] The mouthpiece segment may include a hollow tubular segment. The mouthpiece segment may be a hollow tubular segment. The mouthpiece segment may be a plug of filter material.

[0074] As used herein, an "aerosol cooling element" may refer to a component of an aerosol-generating article located downstream of the aerosol-forming substrate such that an aerosol formed by a volatile compound released from the aerosol-forming substrate during use passes through the aerosol cooling element and is cooled by the aerosol cooling element before being inhaled by the user. The aerosol cooling element has a large surface area but causes a low pressure drop. The aerosol cooling element may act to cool the temperature of the aerosol stream drawn through the element by heat transfer. The components of the aerosol will interact with the aerosol cooling element and the dissipated thermal energy.

[0075] The aerosol cooling element may include a sheet material selected from the group consisting of a metal foil, a polymer sheet, and a substantially non-porous paper or cardboard. In some embodiments, the aerosol cooling element may include 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.

[0076] After consumption, aerosol generating articles are typically discarded. It may be advantageous to make the elements forming the aerosol generating article biodegradable. Thus, the aerosol cooling element may advantageously be formed from a biodegradable material such as, for example, non-porous paper, or a biodegradable polymer such as polylactic acid or a grade of Mater-Bi® (a commercial family of starch-based copolyesters). In some embodiments, the entire aerosol generating article is biodegradable or compostable.

[0077] In some embodiments, the aerosol generating article according to the present invention may comprise an additional support element (or support segment) disposed between the rod of the aerosol forming substrate and the hollow tubular segment or aerosol cooling segment (or element), aligned therewith in the longitudinal axis direction. More specifically, the support element (or support segment) may be provided immediately downstream of the rod and immediately upstream of the hollow tubular segment or aerosol cooling element. The additional support element or segment may be tubular.

[0078] The wrapper of the aerosol-generating article may include an air-impermeable material. The wrapper of the aerosol-generating article may include an air-impervious material. By providing an air-impermeable or air-impervious material to the aerosol-generating article, when the upstream end of the aerosol-generating article is blocked upon insertion into the device cavity or heating chamber of the aerosol-generating device, it is ensured that in order to introduce air into the aerosol-generating article, air needs to be drawn through the first air entry zone. In other words, the first air entry zone may define the main and only air intake portion of the article through which air can be drawn into the article.

[0079] The expressions "air-impermeable material" or "air-impervious material" are used throughout this specification to mean a material that substantially prevents the passage of fluids, particularly air and smoke, through the gaps or pores in the material. For example, if the wrapper is formed of a material that is impermeable to air and aerosol particles, the air and aerosol particles drawn through the article cannot flow across the material of the wrapper. In contrast, the term "porous" is used in this specification to refer to a material that provides a plurality of pores or openings that allow the passage of air therethrough.

[0080] By providing an air-impermeable material to the wrapper, air can access the interior of the aerosol-generating article only through the first air entry zone provided within the wrapper when the article is received within the aerosol-generating device.

[0081] The first air entry zone may be located at a (first) position along the aerosol-generating article. The first air entry zone of the aerosol-generating article may be located along the rod of the aerosol-forming substrate. The first air entry zone may be located around the rod of the aerosol-forming substrate. The first air entry zone of the aerosol-generating article may be located at a position along the rod of the aerosol-forming substrate.

[0082] The first air inlet zone may be located downstream of the rod of the aerosol-forming substrate. The first air inlet zone may be located at least 1 mm downstream of the rod of the aerosol-forming substrate or from the rod.

[0083] The first air inlet zone of the aerosol-generating article may be located along the hollow tubular segment. The first air inlet zone may be located around the hollow tubular segment. The first air inlet zone of the aerosol-generating article may be located at a position along the hollow tubular segment.

[0084] The first air inlet zone of the aerosol-generating article may be located along the support segment. The first air inlet zone may be located around the support segment. The first air inlet zone of the aerosol-generating article may be located at a position along the support segment. The support segment may be a hollow support segment.

[0085] The aerosol-generating article may extend between an upstream end and a downstream end. The downstream end of the article may coincide with the downstream end of the rod of the aerosol-forming substrate. In other words, the downstream end of the rod of the aerosol-forming substrate may define the downstream end of the aerosol-generating article.

[0086] The first air inlet zone may be located at least about 2 mm downstream of the upstream end of the rod of the aerosol-forming substrate. The first air inlet zone may be located at least about 3 mm downstream of the upstream end of the rod of the aerosol-forming substrate. The first air inlet zone may be located at least about 4 mm downstream of the upstream end of the rod of the aerosol-forming substrate. The first air inlet zone may be located at least about 5 mm downstream of the upstream end of the rod of the aerosol-forming substrate. The first air inlet zone may be located at least about 6 mm downstream of the upstream end of the rod of the aerosol-forming substrate. The first air inlet zone may be located at least about 7 mm downstream of the upstream end of the rod of the aerosol-forming substrate. The first air inlet zone may be located at least about 8 mm downstream of the upstream end of the rod of the aerosol-forming substrate. The first air inlet zone may be located at least about 9 mm downstream of the upstream end of the rod of the aerosol-forming substrate. The first air inlet zone may be located at least about 10 mm downstream of the upstream end of the rod of the aerosol-forming substrate. The first air inlet zone may be located at least about 12 mm downstream of the upstream end of the rod of the aerosol-forming substrate.

[0087] The first air inlet zone may be located downstream by about 20 mm or less from the upstream end of the rod of the aerosol-forming substrate. The first air inlet zone may be located downstream by about 15 mm or less from the upstream end of the rod of the aerosol-forming substrate. The first air inlet zone may be located downstream by about 14 mm or less from the upstream end of the rod of the aerosol-forming substrate. The first air inlet zone may be located downstream by about 13 mm or less from the upstream end of the rod of the aerosol-forming substrate. The first air inlet zone may be located downstream by about 12 mm or less from the upstream end of the rod of the aerosol-forming substrate. The first air inlet zone may be located downstream by about 10 mm or less from the upstream end of the rod of the aerosol-forming substrate. The first air inlet zone may be located downstream by about 9 mm or less from the upstream end of the rod of the aerosol-forming substrate. The first air inlet zone may be located downstream by about 8 mm or less from the upstream end of the rod of the aerosol-forming substrate. The first air inlet zone may be located downstream by about 6 mm or less from the upstream end of the rod of the aerosol-forming substrate. The first air inlet zone may be located downstream by about 5 mm or less from the upstream end of the rod of the aerosol-forming substrate.

[0088] The first air inlet zone may be located downstream by about 2 mm to about 20 mm from the upstream end of the rod of the aerosol-forming substrate. The first air inlet zone may be located downstream by about 3 mm to about 15 mm from the upstream end of the rod of the aerosol-forming substrate. The first air inlet zone may be located downstream by about 4 mm to about 12 mm from the upstream end of the rod of the aerosol-forming substrate.

[0089] The first air inlet zone may be located downstream by about 2 mm to about 15 mm from the upstream end of the rod of the aerosol-forming substrate. The first air inlet zone may be located downstream by about 3 mm to about 12 mm from the upstream end of the rod of the aerosol-forming substrate. The first air inlet zone may be located downstream by about 5 mm to about 10 mm from the upstream end of the rod of the aerosol-forming substrate.

[0090] The first air inlet zone may be located about 2 mm to about 12 mm downstream of the upstream end of the rod of the aerosol-forming substrate. The first air inlet zone may be located about 3 mm to about 10 mm downstream of the upstream end of the rod of the aerosol-forming substrate. The first air inlet zone may be located about 5 mm to about 8 mm downstream of the upstream end of the rod of the aerosol-forming substrate.

[0091] The first air inlet zone may be located about 2 mm to about 10 mm downstream of the upstream end of the rod of the aerosol-forming substrate. The first air inlet zone may be located about 3 mm to about 9 mm downstream of the upstream end of the rod of the aerosol-forming substrate. The first air inlet zone may be located about 5 mm to about 8 mm downstream of the upstream end of the rod of the aerosol-forming substrate.

[0092] The first air inlet zone may be located about 2 mm to about 8 mm downstream of the upstream end of the rod of the aerosol-forming substrate. The first air inlet zone may be located about 2 mm to about 6 mm downstream of the upstream end of the rod of the aerosol-forming substrate. The first air inlet zone may be located about 2 mm to about 5 mm downstream of the upstream end of the rod of the aerosol-forming substrate.

[0093] The first air inlet zone may be located about 10 mm to about 20 mm downstream of the upstream end of the rod of the aerosol-forming substrate. The first air inlet zone may be located about 12 mm to about 15 mm downstream of the upstream end of the rod of the aerosol-forming substrate.

[0094] The first air inlet zone may be located along the upstream half of the rod of the aerosol-forming substrate. By positioning the first air inlet zone along the upstream half of the rod of the aerosol-forming substrate, aerosol generation is optimized and, to efficiently use the aerosol-forming substrate, the air drawn through the first air inlet zone can be drawn through a substantial length of the rod of the aerosol-forming substrate.

[0095] The first air inlet zone may be located along the downstream half of the rod of the aerosol-forming substrate. The first air inlet zone may be located along the upstream half of the hollow tubular segment. The first air inlet zone may be located along the upstream half of the support segment. The first air inlet zone may be located along the downstream half of the hollow tubular segment. The first air inlet zone may be located along the downstream half of the support segment.

[0096] Throughout this specification, when it is described that an air inlet zone is located or may be located along a particular component of an aerosol-generating article, this refers to the fact that the air inlet zone is located on a part of a wrapper covering such a component of the aerosol-generating article. For example, when the air inlet zone is located along the rod of the aerosol-forming substrate, this refers to the fact that the air inlet zone is located on a part of the wrapper covering the rod of the aerosol-forming substrate.

[0097] The term "upstream half" refers to the region or part of an element between the upstream end of the element and the midpoint of the element. The term "downstream half" refers to the region or part of an element between the downstream end of the element and the midpoint of the element.

[0098] An aerosol-generating article may be provided with an additional air inlet zone to provide additional functionality to the first air inlet zone. The aerosol-generating article may comprise a second air inlet zone located on the wrapper. Such a second air inlet zone may be configured to provide ventilation to the aerosol-generating article within the device during use as a ventilation zone, and the first air inlet zone functions as an air intake zone of the article. Further, the air inlet zone may be provided to provide additional ventilation to the article during normal and compliant use.

[0099] The second air inlet zone may be located at a (second) position along the aerosol-generating article. The second air inlet zone may be located on the wrapper at a position downstream of the first air inlet zone. The second air inlet zone may be provided at a location along the same component of the aerosol-generating article as the first air inlet zone. For example, if the first air inlet zone is provided along the rod of the aerosol-forming substrate, the second air inlet zone may be provided along the rod of the aerosol-forming substrate at a position downstream of the first air inlet zone.

[0100] The second air inlet zone may be located downstream of the rod of the aerosol-forming substrate. The second air inlet zone may be located downstream of the downstream end of the rod of the aerosol-forming substrate. The second air inlet zone may be located along the filter or downstream action of the aerosol-generating article. The second air inlet zone may be located along the hollow tubular segment. The second air inlet zone may be located along the support segment.

[0101] The second air inlet zone may be located at least about 1 mm downstream of the rod of the aerosol-forming substrate. That is, the second air inlet zone may be located at least 1 mm downstream of the downstream end of the rod of the aerosol-forming substrate. The second air inlet zone may be located at least about 2 mm downstream of the rod of the aerosol-forming substrate. The second air inlet zone may be located at least about 3 mm downstream of the rod of the aerosol-forming substrate.

[0102] The second air inlet zone may be located at about 8 mm or less downstream of the rod of the aerosol-forming substrate. The second air inlet zone may be located at about 7 mm or less downstream of the rod of the aerosol-forming substrate. The second air inlet zone may be located at about 6 mm or less downstream of the rod of the aerosol-forming substrate.

[0103] The second air inlet zone may be located from about 1 mm to about 8 mm downstream of the rod of the aerosol-forming substrate. The second air inlet zone may be located from about 2 mm to about 7 mm downstream of the rod of the aerosol-forming substrate. The second air inlet zone may be located from about 2 mm to about 6 mm downstream of the rod of the aerosol-forming substrate. The second air inlet zone may be located from about 3 mm to about 6 mm downstream of the rod of the aerosol-forming substrate.

[0104] The second air inlet zone may be located at least about 1 mm downstream of the upstream end of the hollow tubular segment. The second air inlet zone may be located at least about 2 mm downstream of the upstream end of the hollow tubular segment. The second air inlet zone may be located at least about 3 mm downstream of the upstream end of the hollow tubular segment.

[0105] The second air inlet zone may be located up to about 8 mm downstream of the upstream end of the hollow tubular segment. The second air inlet zone may be located up to about 7 mm downstream of the upstream end of the hollow tubular segment. The second air inlet zone may be located up to about 6 mm downstream of the upstream end of the hollow tubular segment.

[0106] The second air inlet zone may be located from about 1 mm to about 8 mm downstream of the upstream end of the hollow tubular segment. The second air inlet zone may be located from about 2 mm to about 7 mm downstream of the upstream end of the hollow tubular segment. The second air inlet zone may be located from about 2 mm to about 6 mm downstream of the upstream end of the hollow tubular segment. The second air inlet zone may be located from about 3 mm to about 6 mm downstream of the upstream end of the hollow tubular segment.

[0107] The second air inlet zone may be located at least about 1 mm downstream of the upstream end of the support segment. The second air inlet zone may be located at least about 2 mm downstream of the upstream end of the support segment. The second air inlet zone may be located at least about 3 mm downstream of the upstream end of the support segment.

[0108] The second air inlet zone may be located downstream by about 8 mm or less from the upstream end of the support segment. The second air inlet zone may be located downstream by about 7 mm or less from the upstream end of the support segment. The second air inlet zone may be located downstream by about 6 mm or less from the upstream end of the support segment.

[0109] The second air inlet zone may be located downstream by about 1 mm to about 8 mm from the upstream end of the support segment. The second air inlet zone may be located downstream by about 2 mm to about 7 mm from the upstream end of the support segment. The second air inlet zone may be located downstream by about 2 mm to about 6 mm from the upstream end of the support segment. The second air inlet zone may be located downstream by about 3 mm to about 6 mm from the upstream end of the support segment.

[0110] As described above, the second air inlet zone may be located along the rod of the aerosol-forming substrate. The second air inlet zone may be located downstream by at least about 3.5 mm from the upstream end of the rod of the aerosol-forming substrate. The second air inlet zone may be located downstream by at least about 4 mm from the upstream end of the rod of the aerosol-forming substrate. The second air inlet zone may be located downstream by at least about 6.5 mm from the upstream end of the rod of the aerosol-forming substrate.

[0111] The second air inlet zone may be located downstream by about 20 mm or less from the upstream end of the rod of the aerosol-forming substrate. The second air inlet zone may be located downstream by about 16 mm or less from the upstream end of the rod of the aerosol-forming substrate. The second air inlet zone may be located downstream by about 12 mm or less from the upstream end of the rod of the aerosol-forming substrate.

[0112] The second air inlet zone may be located downstream by about 3.5 mm to about 20 mm from the upstream end of the rod of the aerosol-forming substrate. The second air inlet zone may be located downstream by about 4 mm to about 16 mm from the upstream end of the rod of the aerosol-forming substrate. The second air inlet zone may be located downstream by about 6.5 mm to about 12 mm from the upstream end of the rod of the aerosol-forming substrate.

[0113] The second air inlet zone may be located at least about 1.5 mm downstream of the first air inlet zone. The second air inlet zone may be located at least about 2 mm downstream of the first air inlet zone. The second air inlet zone may be located at least about 3 mm downstream of the first air inlet zone.

[0114] The second air inlet zone may be located at least about 10 mm downstream of the first air inlet zone. The second air inlet zone may be located at least about 12 mm downstream of the first air inlet zone. In such embodiments, the second air inlet zone may be located downstream of the rod of the aerosol-forming substrate.

[0115] The second air inlet zone may be located up to about 20 mm downstream of the first air inlet zone. The second air inlet zone may be located up to about 18 mm downstream of the first air inlet zone. The second air inlet zone may be located up to about 16 mm downstream of the first air inlet zone.

[0116] The second air inlet zone may be located from about 1.5 mm to about 20 mm downstream of the first air inlet zone. The second air inlet zone may be located from about 2 mm to about 18 mm downstream of the first air inlet zone. The second air inlet zone may be located from about 3 mm to about 16 mm downstream of the first air inlet zone.

[0117] The second air inlet zone may be located along the upstream half of the rod of the aerosol-forming substrate. The second air inlet zone may be located along the downstream half of the rod of the aerosol-forming substrate. The second air inlet zone may be located along the upstream half of the hollow tubular segment. The second air inlet zone may be located along the upstream half of the support segment. The second air inlet zone may be located along the downstream half of the hollow tubular segment. The second air inlet zone may be located along the downstream half of the support segment.

[0118] The air inlet zone may include one or more rows of openings or perforations that penetrate the wrapper of the aerosol-generating article. The openings or perforations of the air inlet zone may extend through the filter or downstream section of the aerosol-generating article. The openings or perforations of the air inlet zone may extend through the peripheral wall of the hollow tubular segment of the article. The openings or perforations of the air inlet zone may extend through the peripheral wall of the support segment of the article, particularly when the support segment is hollow.

[0119] The air inlet zone may include only one row of openings or perforations. The row of openings or perforations may comprise from 8 to 30 openings or perforations. The row of openings or perforations may comprise from 10 to 20 openings or perforations. The air inlet zone may surround the aerosol-generating article. The air inlet zone may surround the rod of the aerosol-forming substrate. The air inlet zone may surround the hollow tubular segment. The air inlet zone may surround the support segment.

[0120] The perforations of the air inlet zone may be of uniform size. Alternatively, the perforations may vary in size. By varying the number and size of the perforations, it is possible to adjust the amount of outside air entering the hollow tubular segment when the consumer sucks on the mouthpiece of the aerosol-generating article during use. Advantageously, therefore, it is possible to adjust the ventilation level or air intake level of the aerosol-generating article. The perforations are preferably circular.

[0121] The air inlet perforations can be formed using any suitable technique, for example laser technology, mechanical perforation of the hollow tubular segment or support segment as part of the aerosol-generating article, or pre-perforation of the hollow tubular segment or support segment prior to forming the aerosol-generating article in combination with other elements. The perforations are preferably formed by in-line laser perforation.

[0122] In addition, the inventors have found that in the aerosol-generating article according to the present invention, the cooling and dilution effects caused by introducing ventilation air at a location along the conduit defined by the above-described hollow tubular segment have a surprisingly low-reducing effect on the generation and delivery of phenol-containing species.

[0123] The air inlet zone or ventilation zone may include one or more rows of perforations formed through the peripheral wall of the hollow tubular segment. As described above, the second air inlet zone can be a ventilation zone. The ventilation zone preferably includes only one row of perforations. This is understood to be advantageous in that it is possible to further enhance aerosol nucleation by condensing the cooling effect brought about by ventilation over a short portion of the cavity defined by the hollow tube segment. This is because it is expected that the faster and more dramatic cooling of the flow of volatilized species will act particularly advantageously on the formation of new nuclei of aerosol particles.

[0124] One or more rows of perforations are preferably arranged circumferentially around the wall of the hollow tube. When the ventilation zone comprises two or more rows of perforations formed through the peripheral wall of the hollow tubular segment, the rows are spaced apart from each other in the longitudinal axis direction along the hollow tubular segment.

[0125] The radius of the air inlet perforation or opening may be at least about 0.05 mm. The radius of the air inlet perforation or opening may be at least about 0.06 mm. The radius of the air inlet perforation or opening may be at least about 0.1 mm. The radius of the air inlet perforation may be from about 0.06 mm to about 0.1 mm.

[0126] The equivalent diameter of at least one of the ventilation perforations or air inlet perforations is preferably at least about 100 micrometers. The equivalent diameter of at least one of the ventilation perforations is preferably at least about 150 micrometers. The equivalent diameter of at least one of the ventilation perforations is even more preferably at least about 200 micrometers. Additionally, or alternatively, the equivalent diameter of at least one of the ventilation perforations is preferably less than about 500 micrometers. The equivalent diameter of at least one of the ventilation perforations is more preferably less than about 450 micrometers. The equivalent diameter of at least one of the ventilation perforations is even more preferably less than about 400 micrometers. The term "equivalent diameter" is used herein to mean the diameter of a circle having the same surface area as the cross-section of the ventilation perforation. The cross-section of the ventilation perforation may have any suitable shape. However, circular ventilation perforations are preferred.

[0127] The ventilation perforations or air inlet perforations may be of uniform size. Alternatively, the ventilation perforations may vary in size. By varying the number and size of the ventilation perforations, it is possible to adjust the amount of outside air entering the hollow tubular segment when a consumer sucks on the mouthpiece of the aerosol-generating article during use. Thus, advantageously, it is possible to adjust the ventilation level of the aerosol-generating article.

[0128] The air inlet zone may include a substantially porous portion of the wrapper of the aerosol-generating article. Such a porous portion may be defined in an air-impermeable or air-impervious wrapper of the aerosol-generating article, or may be defined by a different material forming part of the wrapper of the aerosol-generating article. Such a porous portion may be defined by a porous pattern defined in the wrapper. Such a porous portion may define a first or second air inlet zone. Thus, the first or second air inlet zone may have the porosity characteristics of such a porous portion.

[0129] Such porous portions of the wrapper can have a relatively high porosity compared to the remainder of the wrapper of the aerosol generating article. The porosity of such porous portions may be at least about 3000 Corésta units (CU). The porosity of such porous portions may be at least about 5000 Corésta units (CU). The porosity of such porous portions may be less than about 25000 Corésta units (CU). The porosity of such porous portions may be less than about 20000 Corésta units (CU). The porosity of such porous portions may be from about 3000 CU to about 25000 CU. The porosity of such porous portions may be from about 5000 CU to about 20000 CU.

[0130] The width of the air entry zone (first, second, or any air entry zone) may be at least about 1 mm. The width of the air entry zone may be at least about 3 mm. The width of the air entry zone may be at least about 5 mm. The “width” of the air entry zone refers to the sizing of the air entry zone in the axial or major axis direction of the aerosol generating article. This “width” of the air entry zone may be referred to as the “length” of the air entry zone.

[0131] The width of the first air entry zone may be greater than the width of the second air entry zone. Thereby, the first air entry zone functions as the primary air intake of the aerosol generating article when received within a compatible aerosol generating device, and the second or subsequent air entry zones may function as secondary air intake zones or ventilation zones.

[0132] Such relatively wide air entry zones can be formed from porous portions of the wrapper having a relatively high porosity, multiple rows of perforations, or relatively wide perforations (as described above).

[0133] By providing a wide air inlet zone, such as a first air inlet zone, there will be a larger surface area of the first air inlet that overlaps or aligns with the outlet of the air flow channel of the aerosol generating device. Thus, this ensures that fluid communication is established between the outside of the aerosol generating device and the inside of the aerosol generating article received within the device, so that the consumer can properly consume the article. Having a relatively wide air inlet zone can be a major cause of inaccuracies in the manufacture of the air inlet zone that can affect the positional relationship between the outlet of the air flow channel of the device and the air inlet zone.

[0134] The air inlet zone may completely or partially surround the aerosol generating article. The air inlet zone may be located around the aerosol generating article.

[0135] The aerosol generating article may comprise a first air inlet zone and a second air inlet zone located along the rod of the aerosol forming substrate. The aerosol generating article may comprise a first air inlet zone located along the rod of the aerosol forming substrate and a second air inlet zone located downstream of the rod of the aerosol forming substrate. The aerosol generating article may comprise a first air inlet zone located along the rod of the aerosol forming substrate and a second air inlet zone located along a hollow tubular segment. The aerosol generating article may comprise a first air inlet zone located along the rod of the aerosol forming substrate and a second air inlet zone located along a support segment.

[0136] Each air inlet zone may provide or enable a certain level of air entry into the aerosol generating article. The level of air entry may refer to the amount of fluid that can enter through the air inlet zone to enter the inside of the aerosol generating article. The level of air entry may be expressed as the volume (cubic millimeters) of air that can enter through the air inlet zone over a certain period of time (expressed in seconds). The level of air entry may be expressed as a mass flow rate (grams or kilograms / second), or a volume flow rate (milliliters or liters / second).

[0137] The level of air entry into the aerosol-generating article through the first air entry zone can be configured to be greater than the level of air entry into the aerosol-generating article through the second air entry zone. This ensures that when the aerosol-generating article is received within the aerosol-generating device, an appropriate amount of air flows through the first air entry zone during use so as to function as a primary air intake zone for the article, and that the second air entry zone provides ventilation to the article.

[0138] The level of air entry through the air entry zone can be defined as a volumetric flow rate. The level of air entry, i.e., the level of air entry into the aerosol-generating article through the first air entry zone, can be at least about 10 percent greater than the level of air entry (volumetric flow rate) into the aerosol-generating article through the second air entry zone. The level of air entry, i.e., the level of air entry into the aerosol-generating article through the first air entry zone, can be at least about 20 percent greater than the level of air entry (volumetric flow rate) into the aerosol-generating article through the second air entry zone. The level of air entry, i.e., the level of air entry into the aerosol-generating article through the first air entry zone, can be at least about 30 percent greater than the level of air entry (volumetric flow rate) into the aerosol-generating article through the second air entry zone.

[0139] The level of air entry, i.e., the level of air entry into the aerosol-generating article through the first air entry zone, may be less than about 300 percent greater than the level of air entry (volume flow rate) into the aerosol-generating article through the second air entry zone. The level of air entry, i.e., the level of air entry into the aerosol-generating article through the first air entry zone, may be less than about 200 percent greater than the level of air entry (volume flow rate) into the aerosol-generating article through the second air entry zone. The level of air entry, i.e., the level of air entry into the aerosol-generating article through the first air entry zone, may be less than about 100 percent greater than the level of air entry (volume flow rate) into the aerosol-generating article through the second air entry zone. The level of air entry, i.e., the level of air entry into the aerosol-generating article through the first air entry zone, may be less than about 90 percent greater than the level of air entry (volume flow rate) into the aerosol-generating article through the second air entry zone. The level of air entry, i.e., the level of air entry into the aerosol-generating article through the first air entry zone, may be less than about 75 percent greater than the level of air entry (volume flow rate) into the aerosol-generating article through the second air entry zone. The level of air entry, i.e., the level of air entry into the aerosol-generating article through the first air entry zone, may be less than about 60 percent greater than the level of air entry (volume flow rate) into the aerosol-generating article through the second air entry zone.

[0140] Over a certain period of time, from a specific volume of air entering the aerosol-generating device through an air flow channel, or a plurality of air flow channels, a first proportion of such air intake may enter the interior of the aerosol-generating article through the first air entry zone, and a second proportion of such air intake may enter the interior of the aerosol-generating article through the second air entry zone. For example, over a certain period of time T, a volume V of air enters the aerosol-generating device, and then a first proportion (expressed as a proportion of V) of V enters the interior of the aerosol-generating article through the first air entry zone, and a second proportion of V may enter the interior of the aerosol-generating article through the second air entry zone.

[0141] Over a certain period of time, with respect to the total volume of air intake entering the aerosol generator, at least about 50 percent of such total volume can enter the interior of the aerosol generating article through the first air entry zone. Over a certain period of time, with respect to the total volume of air intake entering the aerosol generator, at least about 55 percent of such total volume can enter the interior of the aerosol generating article through the first air entry zone. Over a certain period of time, with respect to the total volume of air intake entering the aerosol generator, at least about 60 percent of such total volume can enter the interior of the aerosol generating article through the first air entry zone. Over a certain period of time, with respect to the total volume of air intake entering the aerosol generator, at least about 70 percent of such total volume can enter the interior of the aerosol generating article through the first air entry zone. Over a certain period of time, with respect to the total volume of air intake entering the aerosol generator, at least about 75 percent of such total volume can enter the interior of the aerosol generating article through the first air entry zone.

[0142] Over a certain period of time, with respect to the total volume of air intake entering the aerosol generator, less than about 50 percent of such total volume can enter the interior of the aerosol generating article through the second air entry zone. Over a certain period of time, with respect to the total volume of air intake entering the aerosol generator, less than about 45 percent of such total volume can enter the interior of the aerosol generating article through the second air entry zone. Over a certain period of time, with respect to the total volume of air intake entering the aerosol generator, less than about 40 percent of such total volume can enter the interior of the aerosol generating article through the second air entry zone. Over a certain period of time, with respect to the total volume of air intake entering the aerosol generator, less than about 30 percent of such total volume can enter the interior of the aerosol generating article through the second air entry zone. Over a certain period of time, with respect to the total volume of air intake entering the aerosol generator, less than about 25 percent of such total volume can enter the interior of the aerosol generating article through the second air entry zone.

[0143] Over a certain period of time, with respect to the total volume of air intake entering the aerosol generating device, approximately 50 percent of such total volume can enter the interior of the aerosol generating article through the first air entry zone, and approximately 50 percent of such total volume can enter the interior of the aerosol generating article through the second air entry zone.

[0144] Over a certain period of time, with respect to the total volume of air intake entering the aerosol generating device, approximately 55 percent of such total volume can enter the interior of the aerosol generating article through the first air entry zone, and approximately 45 percent of such total volume can enter the interior of the aerosol generating article through the second air entry zone.

[0145] Over a certain period of time, with respect to the total volume of air intake entering the aerosol generating device, approximately 60 percent of such total volume can enter the interior of the aerosol generating article through the first air entry zone, and approximately 40 percent of such total volume can enter the interior of the aerosol generating article through the second air entry zone.

[0146] Over a certain period of time, with respect to the total volume of air intake entering the aerosol generating device, approximately 70 percent of such total volume can enter the interior of the aerosol generating article through the first air entry zone, and approximately 30 percent of such total volume can enter the interior of the aerosol generating article through the second air entry zone.

[0147] Over a certain period of time, with respect to the total volume of air intake entering the aerosol generating device, approximately 75 percent of such total volume can enter the interior of the aerosol generating article through the first air entry zone, and approximately 25 percent of such total volume can enter the interior of the aerosol generating article through the second air entry zone.

[0148] Similarly, a specific volume flow rate may flow through the air flow channel or plurality of air flow channels of the aerosol generating device before the air exits the air flow channel towards the aerosol generating article. From such an intake volume flow rate (or the air flow channel volume flow rate present within the air flow channel before the outlet), a first percentage of such an intake volume flow rate may flow through the first air inlet zone and a second percentage of such an intake volume flow rate may flow through the second air inlet zone. For example, the volume flow rate VF may flow through the air flow channel, and then a first percentage (expressed as a percentage of VF) of VF may flow through the first air inlet zone and a second percentage of VF may flow through the second air inlet zone.

[0149] With respect to the intake volume flow rate flowing through the air flow channel of the aerosol generating device, at least about 50 percent of such an intake volume flow rate may flow through the first air inlet zone. With respect to the intake volume flow rate flowing through the air flow channel of the aerosol generating device, at least about 55 percent of such an intake volume flow rate may flow through the first air inlet zone. With respect to the intake volume flow rate flowing through the air flow channel of the aerosol generating device, at least about 60 percent of such an intake volume flow rate may flow through the first air inlet zone. With respect to the intake volume flow rate flowing through the air flow channel of the aerosol generating device, at least about 70 percent of such an intake volume flow rate may flow through the first air inlet zone. With respect to the intake volume flow rate flowing through the air flow channel of the aerosol generating device, at least about 75 percent of such an intake volume flow rate may flow through the first air inlet zone.

[0150] For the intake volume flow rate flowing through the airflow channel of the aerosol generator, less than about 50 percent of such intake volume flow rate may flow through the second air inlet zone. For the intake volume flow rate flowing through the airflow channel of the aerosol generator, less than about 45 percent of such intake volume flow rate may flow through the second air inlet zone. For the intake volume flow rate flowing through the airflow channel of the aerosol generator, less than about 40 percent of such intake volume flow rate may flow through the second air inlet zone. For the intake volume flow rate flowing through the airflow channel of the aerosol generator, less than about 30 percent of such intake volume flow rate may flow through the second air inlet zone. For the intake volume flow rate flowing through the airflow channel of the aerosol generator, less than about 25 percent of such intake volume flow rate may flow through the second air inlet zone.

[0151] For the intake volume flow rate flowing through the airflow channel of the aerosol generator, about 50 percent of such intake volume flow rate may flow through the first air inlet zone and about 50 percent of such intake volume flow rate may flow through the second air inlet zone.

[0152] For the intake volume flow rate flowing through the airflow channel of the aerosol generator, about 55 percent of such intake volume flow rate may flow through the first air inlet zone and about 45 percent of such intake volume flow rate may flow through the second air inlet zone.

[0153] For the intake volume flow rate flowing through the airflow channel of the aerosol generator, about 60 percent of such intake volume flow rate may flow through the first air inlet zone and about 40 percent of such intake volume flow rate may flow through the second air inlet zone.

[0154] For the intake volume flow rate flowing through the airflow channel of the aerosol generating device, about 70 percent of such intake volume flow rate may flow through the first air inlet zone, and about 30 percent of such intake volume flow rate may flow through the second air inlet zone.

[0155] For the intake volume flow rate flowing through the airflow channel of the aerosol generating device, about 75 percent of such intake volume flow rate may flow through the first air inlet zone, and about 25 percent of such intake volume flow rate may flow through the second air inlet zone.

[0156] The term "ventilation level" can be used throughout this specification to indicate the volume ratio between the airflow entering the aerosol generating article through the air inlet zone (inlet airflow) and the airflow exiting the aerosol generating article through the mouth side end or the downstream end. The greater the ventilation level, the higher the dilution of the aerosol stream delivered to the consumer. The ventilation level is measured on the aerosol generating article itself, i.e., without inserting the aerosol generating article into a suitable aerosol generating device adapted to heat the aerosol forming substrate.

[0157] The ventilation level provided by the first air inlet zone, if present, can be measured by drawing air from the mouth side end of the aerosol generating article such that it shields all other air inlet zones, causing air to flow into the aerosol generating article through the front end or upstream end of the aerosol generating article and through the first air inlet zone. The ventilation level provided by the first air inlet zone can be defined as the ratio between the flow rate of air (airflow) entering the aerosol generating article through the first air inlet zone and the flow rate of air exiting the aerosol generating article at the mouth side end.

[0158] The ventilation level provided by the second air inlet zone, if present, can be measured by drawing air from the mouth-side end of the aerosol-generating article such that it shields all other air inlet zones and air flows into the aerosol-generating article through the front or upstream end of the aerosol-generating article and through the second air inlet zone. The ventilation level provided by the second air inlet zone can be defined as the ratio between the flow rate of air (airflow) entering the aerosol-generating article through the second air inlet zone and the flow rate of air exiting the aerosol-generating article at the mouth-side end.

[0159] The total ventilation level of the aerosol-generating article can be measured by drawing air from the mouth-side end of the aerosol-generating article such that it does not shield any air inlet zones present in the aerosol-generating article and air flows into the aerosol-generating article through the front or upstream end of the aerosol-generating article and through the air inlet zones. The total ventilation level of the aerosol-generating article can be defined as the ratio between the sum of the flow rates of air entering the aerosol-generating article through each of the air inlet zones and the flow rate of air exiting the aerosol-generating article at the mouth-side end.

[0160] The ventilation level provided to the aerosol-generating article by the first air inlet zone may be at least about 10 percent. The ventilation level provided by the first air inlet zone may be at least about 20 percent. The ventilation level provided by the first air inlet zone may be at least about 25 percent. The ventilation level provided by the first air inlet zone may be at least about 50 percent. The ventilation level provided by the first air inlet zone may be at least about 75 percent.

[0161] The ventilation level provided to the aerosol-generating article by the second air inlet zone may be at least about 10 percent. The ventilation level provided by the second air inlet zone may be at least about 20 percent. The ventilation level provided by the second air inlet zone may be at least about 25 percent. The ventilation level provided by the second air inlet zone may be at least about 50 percent. The ventilation level provided by the second air inlet zone may be at least about 75 percent.

[0162] The ventilation level provided by the first air inlet zone or by the second air inlet zone may be about 75 percent or less. The ventilation level provided by the first air inlet zone or by the second air inlet zone may be about 60 percent or less. The ventilation level provided by the first air inlet zone or by the second air inlet zone may be about 50 percent or less.

[0163] The ventilation level provided by the first air inlet zone or by the second air inlet zone may be from about 10 percent to about 75 percent. The ventilation level provided by the first air inlet zone or by the second air inlet zone may be from about 30 percent to about 60 percent.

[0164] The aerosol-generating article may typically have a total ventilation level of at least about 10 percent, preferably at least about 20 percent.

[0165] The aerosol-generating article may have a total ventilation level of at least about 20 percent, or at least about 25 percent, or at least about 30. The aerosol-generating article may have a total ventilation level of at least about 35 percent. The aerosol-generating article may have a total ventilation level of less than about 60 percent. The aerosol-generating article may have a total ventilation level of less than about 50 percent, or less than about 40 percent. The aerosol-generating article may have a total ventilation level of from about 25 percent to about 60 percent.

[0166] The aerosol-generating article may have a total ventilation level of from about 10 percent to about 90 percent. The aerosol-generating article may have a total ventilation level of from about 20 percent to about 80 percent. The aerosol-generating article may have a total ventilation level of from about 25 percent to about 60 percent. The aerosol-generating article may have a total ventilation level of from about 30 percent to about 50 percent. The aerosol-generating article may have a total ventilation level of from about 30 percent to about 40 percent.

[0167] The aerosol-generating article may have a total ventilation level of from about 28 percent to about 42 percent. The aerosol-generating article may have a ventilation level of about 35 percent. The inventors have surprisingly found that the dilution effect on the aerosol (which can be evaluated by measuring the effect on the delivery of glycerin contained in the aerosol-forming substrate as an aerosol-forming agent) is advantageously minimized when the ventilation level is from about 30 percent to about 50 percent. In particular, a ventilation level of from about 35 percent to about 42 percent has been found to lead to particularly satisfactory values for glycerin delivery. At the same time, the degree of nucleation and, as a result, the delivery of nicotine and aerosol-forming agents (such as glycerol) are enhanced.

[0168] The first air inlet zone may function as a first, or primary air intake zone, and the second air inlet zone may function as a ventilation zone for the aerosol generating article. This is because the first inlet zone is configured to be the first point of air intake when the aerosol generating article is located within the device cavity and may be configured to admit the highest level of air compared to any other air inlet zones provided on the wrapper of the article.

[0169] The first air inlet zone, as described above, ensures the compatibility between the aerosol generating article and the aerosol generating device by defining the primary air intake zone of the article, and the second air inlet zone provides ventilation to the aerosol generating article during normal use when the aerosol generating article is received within the device. All air inlet zones may be located within the device cavity or the heating chamber of the aerosol generating device during normal use. This may prevent any of the air inlet zones from being inadvertently blocked by a hand or lip during normal use, which could otherwise negatively impact the user experience as the article may not be properly ventilated.

[0170] There are advantages to providing ventilation to the aerosol generating article during normal use. Without wishing to be bound by theory, it has been found that the temperature drop resulting from admitting cooler outside air into the hollow tubular segment through the ventilation zone may have a beneficial effect on the nucleation and growth of aerosol particles.

[0171] In this scenario (where the scenario is further complicated by the coalescence phenomenon), the temperature and rate of cooling can play an important role in determining how the system responds. Generally, because the nucleation process is typically non-linear, different cooling rates can lead to significantly different temperature behaviors with respect to the formation of the liquid phase (droplets). Without wishing to be bound by theory, it is hypothesized that cooling can cause a rapid increase in the number of droplets that condense, followed by a strong increase in this growth for a short period (nucleation burst). This nucleation burst is thought to be more pronounced at lower temperatures. Additionally, a faster cooling rate may be favorable for the onset of early nucleation. In contrast, a decrease in the cooling rate is thought to have a beneficial effect on the final size that the aerosol droplets ultimately reach.

[0172] Therefore, the rapid cooling induced by introducing outside air into the hollow tubular segment through the ventilation zone can be used to advantage for the favorable nucleation and growth of aerosol droplets. However, at the same time, introducing outside air into the hollow tubular segment has the direct drawback of diluting the aerosol stream delivered to the consumer.

[0173] In addition, in the aerosol generating article according to the present invention, it has been found that the cooling and dilution effects resulting from introducing ventilation air at a location along the conduit defined by the above-described hollow tubular segment have a surprising decreasing effect on the generation and delivery of phenol-containing species.

[0174] This is understood to be advantageous in that the nucleation of the aerosol may be further enhanced by condensing the cooling effect brought about by ventilation over a short portion of the cavity defined by the hollow tubular segment. This is because a faster and more dramatic cooling of the stream of species volatilized from the aerosol-forming substrate is expected to act particularly favorably on the formation of new nuclei of aerosol particles.

[0175] The rod of the aerosol-forming substrate preferably has an outer diameter substantially equal to the outer diameter of the aerosol-generating article.

[0176] The rod of the aerosol-forming substrate preferably has an outer diameter of at least about 4 millimeters (mm). The rod of the aerosol-forming substrate may have an outer diameter of at least about 5 millimeters. The rod of the aerosol-forming substrate may have an outer diameter in the range of about 5 millimeters to about 12 millimeters, such as an outer diameter in the range of about 5 millimeters to about 10 millimeters, or an outer diameter in the range of about 6 millimeters to about 8 millimeters. In a preferred embodiment, the rod of the aerosol-forming substrate has an outer diameter of 7.2 millimeters ± 10 percent.

[0177] The rod of the aerosol-forming substrate may have a length in the range of about 5 millimeters to about 100 mm. The rod of the aerosol-forming substrate preferably has a length of at least about 5 millimeters, more preferably at least about 7 millimeters. Additionally, or alternatively, the rod of the aerosol-forming substrate preferably has a length of less than about 80 millimeters, more preferably less than about 65 millimeters, even more preferably less than about 50 millimeters. In a particularly preferred embodiment, the rod of the aerosol-forming substrate has a length of less than about 35 millimeters, more preferably a length of less than 25 millimeters, even more preferably a length of less than about 20 millimeters. In one embodiment, the rod of the aerosol-forming substrate may have a length of about 10 millimeters. In a preferred embodiment, the rod of the aerosol-forming substrate has a length of about 12 millimeters.

[0178] The rod of the aerosol-forming substrate preferably has a substantially uniform cross-section along the length of the rod. The rod of the aerosol-forming substrate particularly preferably has a substantially circular cross-section.

[0179] In a preferred embodiment, the aerosol-forming substrate comprises an assembly of one or more sheets of homogenized tobacco material. The one or more sheets of homogenized tobacco material may be textured. As used herein, the term "textured sheet" means a sheet that is crimped, embossed, debossed, perforated, or otherwise deformed. The textured sheets of homogenized tobacco material used in the present invention may include a plurality of spaced depressions, protrusions, perforations, or combinations thereof. The rod of the aerosol-forming substrate may include an assembly of crimped sheets of homogenized tobacco material surrounded by a wrapper.

[0180] In certain preferred embodiments, the aerosol-forming substrate comprises homogenized plant material, preferably homogenized tobacco material.

[0181] As used herein, the term "homogenized plant material" encompasses any plant material formed by the aggregation of plant particles. For example, a sheet or web of homogenized tobacco material for the aerosol-forming substrate of the present invention can be formed by aggregating tobacco material particles obtained by grinding, pulverizing, or subdividing plant material and optionally one or more of tobacco leaf lamina and tobacco leaf stems. The homogenized plant material may be produced by casting, extrusion, a papermaking process, or any other suitable process known in the art.

[0182] The homogenized plant material can be provided in any suitable form. For example, the homogenized plant material can be in the form of one or more sheets. As used herein in connection with the present invention, the term "sheet" describes a thin, layer-like element having a width and length that are considerably larger than its thickness.

[0183] Alternatively or additionally, the homogenized plant material can be in the form of a plurality of pellets or granules.

[0184] Alternatively, or in addition, the homogenized plant material can be in the form of a plurality of strands, flakes, or pieces. As used herein, the term "strand" describes an elongated element of material having a length that is substantially greater than its width and thickness. The term "strand" is considered to encompass flakes, pieces, and any other homogenized plant material having a similar form. Strands of homogenized plant material may be formed, for example, by cutting or shredding, or by other means, such as an extrusion process, from a sheet of homogenized plant material.

[0185] As used herein, the term "crimped sheet" is intended to be synonymous with the term "creased sheet" and means a sheet having a plurality of substantially parallel ridges or undulations. A crimped sheet of homogenized tobacco material preferably has a plurality of ridges or undulations that are substantially parallel to the cylindrical axis of the rod according to the invention. This advantageously facilitates the assembly of a collection of crimped sheets of homogenized tobacco material for forming a rod. However, it will be understood that the crimped sheets of homogenized tobacco material used in the present invention can alternatively or additionally have a plurality of substantially parallel ridges or undulations arranged at an acute or obtuse angle to the cylindrical axis of the rod. In certain embodiments, the sheet of homogenized tobacco material used in the rod of the article of the present invention may be substantially evenly textured over substantially its entire surface. For example, a crimped sheet of homogenized tobacco material used in the manufacture of a rod for use in an aerosol generating article according to the present invention may include a plurality of substantially parallel ridges or undulations that are substantially evenly spaced across the width of the sheet.

[0186] The sheet or web 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 60 weight percent on a dry weight basis, still more preferably at least about 70 weight percent on a dry basis, and most preferably at least about 90 weight percent on a dry weight basis.

[0187] The sheet or web of homogenized tobacco material used in an aerosol-forming substrate may contain one or more endogenous binders, i.e., tobacco endogenous binders, one or more exogenous binders, i.e., tobacco exogenous binders, or combinations thereof, to assist in aggregating particulate tobacco. Alternatively or additionally, the sheet of homogenized tobacco material used in an aerosol-forming substrate may contain tobacco fibers and non-tobacco fibers, aerosol formers, humectants, plasticizers, flavorants, fillers, aqueous and non-aqueous solvents, and other additives including but not limited to combinations thereof.

[0188] The homogenized plant material or tobacco material contains tobacco particles or tobacco material in combination with non-tobacco plant flavor particles. The non-tobacco plant flavor particles can be selected from one or more of ginger particles, rosemary particles, eucalyptus particles, clove particles, and star anise particles.

[0189] Suitable exogenous binders for inclusion in the sheet or web of homogenized tobacco material used in an aerosol-forming substrate are known in the art and include gums (such as guar gum, xanthan gum, gum arabic, locust bean gum, etc.), cellulose-based binders (such as hydroxypropyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, methyl cellulose, ethyl cellulose, etc.), polysaccharides (such as starch, organic acids (such as alginic acid), conjugate base salts of organic acids (such as sodium alginate), agar, pectin, etc.), and combinations thereof, but are not limited thereto.

[0190] Suitable non-tobacco fibers for inclusion in a sheet or web of homogenized tobacco material for use in an aerosol-forming substrate are known in the art and include, but are not limited to, cellulose fibers, coniferous fibers, hardwood fibers, jute fibers, and combinations thereof. Prior to inclusion in a sheet of homogenized tobacco material for use in an aerosol-forming substrate, the non-tobacco fibers may be processed by suitable processes known in the art, including but not limited to mechanical pulping, refining, chemical pulping, bleaching, sulfate pulping, and combinations thereof.

[0191] In another embodiment of the present invention, the aerosol-forming substrate may comprise a gel composition comprising an alkaloid compound, or a cannabinoid compound, or both an alkaloid compound and a cannabinoid compound. The aerosol-forming substrate may comprise a gel composition comprising nicotine. The aerosol-forming substrate may comprise a gel composition that does not contain nicotine.

[0192] Preferably, the gel composition comprises an alkaloid compound, or a cannabinoid compound, or both an alkaloid compound and a cannabinoid compound, an aerosol former, and at least one gelling agent. Preferably, the at least one gelling agent forms a solid medium, glycerol is dispersed in the solid medium, and the alkaloid or cannabinoid is dispersed in the glycerol. The gel composition is preferably in a stable gel phase.

[0193] Advantageously, a stable gel composition containing nicotine provides a predictable composition form during storage or during transfer from manufacture to the consumer. A stable gel composition containing nicotine substantially maintains its shape. A stable gel composition containing nicotine does not substantially release a liquid phase during storage or during transfer from manufacture to the consumer. A stable gel composition containing nicotine may provide a simple consumable design. This consumable may not need to be designed to contain a liquid, and thus a wider range of materials and container structures may be contemplated.

[0194] The gel compositions described herein may be combined with an aerosol generating device to provide nicotine aerosol to the lungs at an inhalation rate or airflow rate within the inhalation rate or airflow rate of conventional smoking methods. The aerosol generating device may continuously heat the gel composition. Consumers may take a plurality of inhalations or "puffs" where each "puff" delivers an amount of nicotine aerosol. The gel composition can deliver a high nicotine / total particulate matter (TPM) aerosol to the consumer, preferably in a continuous manner, upon heating.

[0195] The phrase "stable gel phase" or "stable gel" refers to a gel that substantially maintains its shape and mass when exposed to various environmental conditions. A stable gel cannot substantially release or absorb water (sweat) when exposed to standard temperature and pressure while varying the relative humidity from about 10 percent to about 60 percent. For example, a stable gel can substantially maintain its shape and mass when exposed to standard temperature and pressure while varying the relative humidity from about 10 percent to about 60 percent.

[0196] The gel composition includes an alkaloid compound, or a cannabinoid compound, or both an alkaloid compound and a cannabinoid compound. The gel composition may include one or more alkaloids. The gel composition may include one or more cannabinoids. The gel composition may include a combination of one or more alkaloids and one or more cannabinoids.

[0197] The term "alkaloid compound" means any one or more classes of naturally occurring organic compounds containing 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 within 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 cyclic system, such as a heterocycle. In nature, alkaloid compounds are mainly found in plants and are particularly common in certain families of flowering plants. However, some alkaloid compounds are found in animal species and fungi. In the present disclosure, the term "alkaloid compound" refers to both naturally occurring alkaloid compounds and synthetically produced alkaloid compounds.

[0198] The gel composition preferably contains an alkaloid compound selected from the group consisting of nicotine, anatabine, and combinations thereof.

[0199] Preferably, the gel composition contains nicotine.

[0200] The term "nicotine" refers to nicotine and nicotine derivatives (such as free base nicotine, nicotine salts, and the like).

[0201] The term "cannabinoid compound" means any one type of natural compound found in parts of the cannabis plants Cannabis sativa, Cannabis indica, and Cannabis ruderalis. Cannabinoid compounds are particularly concentrated in the female flower heads. Cannabinoid compounds that occur naturally in the cannabis plant include cannabidiol (CBD) and tetrahydrocannabinol (THC). In the present disclosure, the term "cannabinoid compound" is used to describe both naturally occurring cannabinoid compounds and synthetically produced cannabinoid compounds.

[0202] The gel may contain a cannabinoid compound selected from the group consisting of cannabidiol (CBD), tetrahydrocannabinol (THC), tetrahydrocannabinolic acid (THCA), cannabidiolic acid (CBDA), cannabinol (CBN), cannabigerol (CBG), cannabichromene (CBC), cannabicyclol (CBL), cannabivarin (CBV), tetrahydrocannabivarin (THCV), cannabidivarin (CBDV), cannabichromevarin (CBCV), cannabigerovarin (CBGV), cannabigerol monomethyl ether (CBGM), cannabinol (CBE), cannabicitran (CBT), and combinations thereof.

[0203] The gel composition may preferably contain a cannabinoid compound selected from the group consisting of cannabidiol (CBD), THC (tetrahydrocannabinol), and combinations thereof.

[0204] The gel preferably contains cannabidiol (CBD).

[0205] The gel composition may contain nicotine and cannabidiol (CBD).

[0206] The gel composition may contain nicotine, cannabidiol (CBD), and THC (tetrahydrocannabinol).

[0207] The gel composition preferably contains 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 polyhydric alcohols (such as triethylene glycol, 1,3 - butanediol, glycerin, etc.), esters of polyhydric alcohols (such as glycerol monoacetate, diacetate, or triacetate, etc.), and aliphatic esters of monocarboxylic acids, dicarboxylic acids, or polycarboxylic acids (such as dimethyl dodecanedioate, dimethyl tetradecanedioate, etc.), but are not limited thereto. The polyhydric alcohol or a mixture thereof can 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.

[0208] Preferably, as described above, in embodiments where the rod of the aerosol - forming substrate contains the gel composition, the downstream section of the aerosol - generating article comprises an aerosol cooling element having a length of less than about 10 millimeters. It has been found that using a relatively short aerosol cooling element in combination with the gel composition optimizes the delivery of the aerosol to the consumer.

[0209] Embodiments of the present invention in which the rod of the aerosol - forming substrate contains the gel composition as described above preferably comprise an upstream element (or upstream section) upstream of the rod of the aerosol - forming substrate. In this case, the upstream element or section advantageously prevents physical contact with the gel composition. The upstream element or section can also advantageously compensate for any potential decrease in RTD, for example, due to evaporation of the gel composition when the rod of the aerosol - forming substrate is heated during use.

[0210] A sheet or web of homogenized tobacco material may contain one aerosol former. As used herein, the term "aerosol former" describes any suitable known compound or mixture of compounds that facilitates the formation of an aerosol upon use and is substantially resistant to thermal decomposition at the operating temperature of the aerosol-generating article.

[0211] Suitable aerosol formers are known in the art and include, but are not limited to, polyhydric alcohols (such as propylene glycol, triethylene glycol, 1,3 - butanediol, glycerin, etc.), esters of polyhydric alcohols (such as glycerol monoacetate, diacetate, triacetate, etc.), and aliphatic esters of monocarboxylic, dicarboxylic or polycarboxylic acids (such as dimethyl dodecanedioate, dimethyl tetradecanedioate, etc.).

[0212] Preferred aerosol formers are polyhydric alcohols (such as propylene glycol, triethylene glycol, 1,3 - butanediol, and most preferably glycerin, etc.) or mixtures thereof.

[0213] A sheet or web of homogenized tobacco material may contain a single aerosol former. Alternatively, a sheet or web of homogenized tobacco material may contain a combination of two or more aerosol formers.

[0214] A sheet or web of homogenized tobacco material has an aerosol former content of more than 10 percent on a dry weight basis. Preferably, a sheet or web of homogenized tobacco material has an aerosol former content of more than 12 percent on a dry weight basis. More preferably, a sheet or web of homogenized tobacco material has an aerosol former content of more than 14 percent on a dry weight basis. Even more preferably, a sheet or web of homogenized tobacco material has an aerosol former content of more than 16 percent on a dry weight basis.

[0215] The sheet of homogenized tobacco material may have an aerosol former content of approximately 10 percent to approximately 30 percent on a dry weight basis. The sheet or web of homogenized tobacco material preferably has an aerosol former content of less than 25 percent on a dry weight basis.

[0216] In a preferred embodiment, the sheet of homogenized tobacco material has an aerosol former content of approximately 20 percent on a dry weight basis.

[0217] The sheet or web of homogenized tobacco for use in the aerosol-generating article of the present invention may be produced by methods known in the art (for example, the method disclosed in International Patent Application No. WO-A-2012 / 164009 (A2)). In a preferred embodiment, the sheet of homogenized tobacco material for use in an aerosol-generating article is formed from a slurry comprising particulate tobacco, guar gum, cellulose fibers, and glycerin by a casting process.

[0218] Alternative arrangements of the homogenized tobacco material within the rod for use in an aerosol-generating article are known to those skilled in the art and may include a plurality of stacked sheets of homogenized tobacco material, a plurality of elongated tubular elements formed by winding strips of homogenized tobacco material around the axis in the longitudinal direction, and the like.

[0219] As a further alternative, the rod of the aerosol-forming substrate may comprise a material having nicotine from a non-tobacco source, such as a sheet of absorbent non-tobacco material loaded with nicotine (for example, in the form of a nicotine salt) and an aerosol former. Examples of such rods are described in International Application No. WO-A-2015 / 052652. Additionally, or alternatively, the rod of the aerosol-forming substrate may comprise a non-tobacco plant material, such as a fragrant non-tobacco plant material.

[0220] The aerosol-forming substrate is surrounded by a wrapper. The wrapper may be formed of a porous or non-porous sheet material. The wrapper may be formed of any suitable material or combination of materials. The wrapper is preferably a paper wrapper.

[0221] The mouthpiece segment comprises a plug of filter material having the ability to remove particulate, gaseous, or combined components. Suitable filter materials are known in the art and include, but are not limited to, fibrous filter materials (e.g., cellulose acetate tow, viscose fiber, polyhydroxyalkanoate (PHA) fiber, polylactic acid (PLA) fiber, paper, etc.), adsorbents (e.g., activated alumina, zeolite, molecular sieve, silica gel, etc.), and combinations thereof. Additionally, the plug of filter material may further comprise one or more aerosol modifiers. Suitable aerosol modifiers are known in the art and include, but are not limited to, flavoring agents such as menthol. In some embodiments, the mouthpiece segment may further comprise a recess at the mouth-side end downstream of the plug of filter material. As an example, the mouthpiece segment may comprise a hollow tube aligned axially with the plug of filter material and disposed immediately downstream of the plug of filter material, the hollow tube forming a cavity at the mouth-side end that is open to the outside environment at the downstream end of the mouthpiece segment and the aerosol-generating article.

[0222] The length of the mouthpiece segment is preferably at least about 4 millimeters, more preferably at least about 6 millimeters, and even more preferably at least about 8 millimeters. Additionally, or alternatively, the length of the mouthpiece segment is preferably less than 25 millimeters, more preferably less than 20 millimeters, and even more preferably less than 15 millimeters. In some preferred embodiments, the length of the mouthpiece segment is from about 4 millimeters to about 25 millimeters, and more preferably from about 6 millimeters to about 20 millimeters. The length of the mouthpiece segment may be about 7 millimeters. The length of the mouthpiece segment may be about 12 millimeters.

[0223] The length of the hollow tubular segment is preferably at least about 10 millimeters. The length of the hollow tubular segment is more preferably at least about 15 millimeters. Additionally, or alternatively, the length of the hollow tubular segment is preferably less than about 30 millimeters. The length of the hollow tubular segment is more preferably less than about 25 millimeters. The length of the hollow tubular segment is even more preferably less than about 20 millimeters. In some preferred embodiments, the length of the hollow tubular segment is from about 10 millimeters to about 30 millimeters, more preferably from about 12 millimeters to about 25 millimeters, and even more preferably from about 15 millimeters to about 20 millimeters. As an example, in one particularly preferred embodiment, the length of the hollow tubular segment is about 18 millimeters. In another particularly preferred embodiment, the length of the hollow tubular segment is about 13 millimeters.

[0224] The length of the aerosol cooling element is preferably at least about 10 millimeters. More preferably, the length of the aerosol cooling element is at least about 15 millimeters. Additionally, or alternatively, the length of the aerosol cooling element is preferably less than about 30 millimeters. More preferably, the length of the aerosol cooling element is less than about 25 millimeters. Even more preferably, the length of the aerosol cooling element is less than about 20 millimeters. In some preferred embodiments, the length of the aerosol cooling element is from about 10 millimeters to about 30 millimeters, more preferably from about 12 millimeters to about 25 millimeters, and even more preferably from about 15 millimeters to about 20 millimeters. As an example, in one particularly preferred embodiment, the length of the aerosol cooling element is about 18 millimeters. In another particularly preferred embodiment, the length of the aerosol cooling element is about 13 millimeters.

[0225] The overall length of the aerosol generating article according to the present invention is preferably at least about 40 millimeters. Additionally, or alternatively, the overall length of the aerosol generating article according to the present invention is preferably less than about 70 millimeters, more preferably less than 60 millimeters, and even more preferably less than 50 millimeters. In a preferred embodiment, the overall length of the aerosol generating article is from about 40 millimeters to about 70 millimeters. In an exemplary embodiment, the overall length of the aerosol generating article is about 45 millimeters.

[0226] The support element (or support segment) can have a length of from about 5 millimeters to about 15 millimeters. In a preferred embodiment, the support element has a length of about 8 millimeters.

[0227] The aerosol-generating article preferably has an overall RTD of less than about 90 millimeters H2O (about 900 Pa). More preferably, the aerosol-generating article has an overall RTD of less than about 80 millimeters H2O (about 800 Pa). Even more preferably, the aerosol-generating article has an overall RTD of less than about 70 millimeters H2O (about 700 Pa).

[0228] In addition or alternatively, the aerosol-generating article preferably has an overall RTD of at least about 30 millimeters H2O (about 300 Pa). More preferably, the aerosol-generating article has an overall RTD of at least about 40 millimeters H2O (about 400 Pa). Even more preferably, the aerosol-generating article has an overall RTD of at least about 50 millimeters H2O (about 500 Pa).

[0229] The RTD of the aerosol-generating article may be evaluated as the negative pressure applied at the downstream end of the mouthpiece to maintain a stable air volume flow rate of 17.5 ml / s through the mouthpiece under test conditions as defined in ISO3402. The RTD values listed above are intended to be measured on the aerosol-generating article itself (i.e., before inserting the article into the aerosol-generating device) without blocking the perforations of the ventilation zone.

[0230] As used herein, the term "homogenized tobacco material" encompasses any tobacco material formed by the aggregation of tobacco material particles. A sheet or web of homogenized tobacco material is formed by aggregating particulate tobacco obtained by grinding one or both of the blade of a tobacco leaf and the stem of a tobacco leaf, or by powdering in other ways. In addition, the homogenized tobacco material may include one or more of a small amount of tobacco dust, tobacco fines, and other particulate tobacco by-products formed during the processing, handling, and shipping of tobacco. The sheet of homogenized tobacco material may be produced by casting, extrusion, a papermaking process, or any other suitable process known in the art.

[0231] 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 sulfuric acid paper), and polymeric materials (such as low-density polyethylene (LDPE)). In a preferred embodiment, the support element is formed from cellulose acetate.

[0232] The aerosol generating device can include an extractor for extracting an aerosol generating article received within the aerosol generating device, and the extractor is configured to be movable within the device cavity.

[0233] The extractor may be configured to expose the airflow channel when the extractor is in the operating position, and the operating position is defined by the heater contacting the aerosol forming substrate of the aerosol generating article.

[0234] The extractor comprises a container body configured to receive an aerosol-generating article. The container body of the extractor (extractor body) may comprise an end wall and a peripheral wall. The container body of the extractor has an open end opposite the end wall, through which the aerosol-generating article can be received. The aerosol-generating article is configured to abut against the end wall when received within the extractor body. The peripheral wall of the container body can surround the aerosol-generating article when received within the extractor. In such embodiments where the extractor is present, the peripheral wall of the extractor body may define an airflow channel. Alternatively, the peripheral wall of the device housing may define an airflow channel.

[0235] The extractor may be sized such that, in the operating position, the container body extends between a first end of the airflow channel and the distal end of the device cavity. This enables the aerosol-generating article to be directly exposed to the airflow channel without the extractor body obscuring the fluid communication between the airflow channel and the aerosol-generating article.

[0236] The extractor can be sized such that, in the operating position, the container body extends between the mouth-side end and the distal end of the device cavity. In such embodiments, the extractor body may have a cut-out or a plurality of cut-outs such that, when inserted, the airflow channel can be exposed to the aerosol-generating article. The extractor body and the device cavity may together be configured to ensure alignment with the airflow channel or a plurality of airflow channels during use of the cut-out or plurality of cut-outs. For example, the extractor body may comprise a protrusion arranged to cooperate with a slot or groove located within the housing of the aerosol-generating device.

[0237] The aerosol generating device may comprise an elongate heater arranged to be inserted into the aerosol generating article when the aerosol generating article is received within the device cavity. The elongate heater may be arranged together with the device cavity. The elongate heater may extend into the device cavity. Alternative heating arrangements are considered further below. However, in such embodiments where the heater extends into the device cavity, the extractor body comprises an opening in the end wall to enable the heater to extend into the aerosol generating article. Such an opening may enable air to enter the interior of the extractor cavity so that air can flow through the rod of the aerosol forming substrate of the aerosol generating article during use. Alternatively, additional openings may be provided to enable air to enter the interior of the extractor cavity.

[0238] In some embodiments, the length of the extractor body may be less than the length of the device cavity. In such embodiments, when the extractor is in the operating position (when the extractor abuts the distal end of the device cavity), the airflow channel may be defined by a portion of the peripheral wall of the device housing that does not surround the extractor. Such a portion of the peripheral wall may define the airflow channel when the extractor is in the operating position. Effectively, the said portion of the peripheral wall of the device housing may extend axially beyond the extractor so as to define the airflow channel. The space or gap between the aerosol generating article and the peripheral wall of the device housing defines the airflow channel.

[0239] In embodiments where an extractor is provided, an airflow channel may be defined between the peripheral wall of the aerosol generating device housing and the outer surface of the extractor. Alternatively, the airflow channel may be defined within the extractor body. The airflow channel may be defined in the peripheral wall of the extractor body. The airflow channel may be defined within the thickness of the peripheral wall of the extractor body. The airflow channel may extend along the length of the extractor body. The airflow channel may extend from an axial position remote from the end wall of the extractor body, near the open end of the extractor body, or at the axial position at the open end of the extractor body.

[0240] In embodiments where no extractor is provided, the airflow channel may be defined within the thickness of the peripheral wall of the aerosol generator housing.

[0241] The heater may comprise an elongate heating element configured to penetrate the rod of the aerosol-forming substrate when the aerosol-generating article is received within the aerosol generator.

[0242] The heater may be of any suitable type. The heater may first heat the aerosol-generating article. Alternatively, the heater may heat the aerosol-generating article from the outside. Such an external heater may surround the aerosol-generating article when inserted or received within the aerosol generator.

[0243] In some embodiments, the heater is arranged to heat the outer surface of the aerosol-forming substrate. In some embodiments, the heater is arranged to be inserted into the aerosol-forming substrate when the aerosol-forming substrate is received within a cavity. The heater may be positioned within the cavity. The heater may extend into the cavity. The heater may be an elongate heater. The elongate heater may be in the shape of a blade. The elongate heater may be in the shape of a pin. The elongate heater may be in the shape of a cone. In some embodiments, the aerosol generator comprises an elongate heater arranged to be inserted into the aerosol-generating article when the aerosol-generating article is received within a cavity.

[0244] The heater may comprise at least one heating element. The at least one heating element can be any suitable type of heating element. In some embodiments, the device comprises only one heating element. In some embodiments, the device comprises a plurality of heating elements. The heater may include at least one resistive heating element. Preferably, the heater includes a plurality of resistive heating elements. The resistive heating elements are preferably electrically connected in a parallel arrangement. Advantageously, providing a plurality of resistive heating elements electrically connected in a parallel arrangement can facilitate the delivery of the desired power to the heater while reducing or minimizing the voltage required to provide the desired power. Advantageously, reducing or minimizing the voltage required to operate the heater can facilitate reducing or minimizing the physical size of the power source.

[0245] Suitable materials for forming at least one resistive heating element include, but are not limited to, semiconductors such as doped ceramics, "conductive" ceramics (e.g., molybdenum disilicide, etc.), carbon, graphite, metals, metal alloys, and composite materials made of ceramic materials and metal materials. Such composite materials may include doped ceramics or undoped ceramics. Examples of suitable doped ceramics include doped silicon carbide. Examples of suitable metals include titanium, zirconium, tantalum, and platinum group metals. Examples of suitable metal alloys include stainless steel, nickel-containing, cobalt-containing, chromium-containing, aluminum-containing, titanium-containing, zirconium-containing, hafnium-containing, niobium-containing, molybdenum-containing, tantalum-containing, tungsten-containing, tin-containing, gallium-containing, manganese-containing, and iron-containing alloys, as well as nickel, iron, cobalt, stainless steel-based superalloys, Timetal®, and iron-manganese-aluminum-based alloys.

[0246] In some embodiments, at least one resistive heating element comprises one or more stamped portions of an electrically resistive material (such as stainless steel). Alternatively, at least one resistive heating element may comprise a heating wire or filament (e.g., a wire of Ni—Cr (nickel-chromium), platinum, tungsten or alloy).

[0247] In some embodiments, at least one heating element comprises an electrically insulated substrate, and at least one resistive heating element is provided on the electrically insulated substrate.

[0248] The electrically insulated substrate can comprise any suitable material. For example, the electrically insulated substrate can comprise one or more of paper, glass, ceramic, anodized metal, coated metal, and polyimide. The ceramic can comprise mica, alumina (Al2O3) or zirconia (ZrO2). The electrically insulated substrate preferably has a thermal conductivity of about 40 watts per meter kelvin or less, preferably about 20 watts per meter kelvin or less, and ideally about 2 watts per meter kelvin or less.

[0249] The heater can comprise a heating element including a rigid electrically insulated substrate having one or more conductive tracks or wires arranged on its surface. Depending on the size and shape of the electrically insulated substrate, it may be possible to insert the heater directly into the aerosol-forming substrate. If the electrically insulated substrate is not sufficiently rigid, the heating element may include additional reinforcing means. Current can pass through one or more conductive tracks to heat the heating element and the aerosol-forming substrate.

[0250] In some embodiments, the heater comprises 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, the high-frequency oscillating current means an oscillating current having a frequency of 500 kHz to 30 MHz. Advantageously, the heater may include a DC / AC inverter for converting a DC current supplied by a DC power source into an alternating current. The inductor coil may be arranged to generate a high-frequency oscillating electromagnetic field when 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. In some embodiments, the inductor coil can substantially surround the device cavity. The inductor coil may extend at least partially along the length of the device cavity.

[0251] 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 having the ability to convert electromagnetic energy into heat. When the susceptor element is located within an alternating electromagnetic field, the susceptor is heated. The heating of the susceptor element may be the result of at least one of the hysteresis losses and eddy currents induced within the susceptor, depending on the electrical and magnetic properties of the susceptor material.

[0252] The susceptor element may be arranged such that when the 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 within the susceptor element, heating the susceptor element. In these embodiments, it is preferred that the aerosol-generating device has the ability to generate a fluctuating electromagnetic field having a magnetic field strength (strength of the H field) of 1 to 5 kiloamperes per meter (kA / m), preferably 2 to 3 kA / m, for example about 2.5 kA / m. It is preferred that an electrically operating aerosol-generating device has the ability to generate a fluctuating electromagnetic field having a frequency of 1 to 30 MHz, for example 1 to 10 MHz, for example 5 to 7 MHz.

[0253] In some embodiments, the susceptor element is located within the aerosol-generating article. In these embodiments, the susceptor element is preferably positioned in contact with the aerosol-forming substrate. The susceptor element may be located within the aerosol-forming substrate.

[0254] In some embodiments, the susceptor element is located within the aerosol-generating device. In these embodiments, the susceptor element may be located within a cavity. The aerosol-generating device may include only one susceptor element. The aerosol-generating device may comprise a plurality of susceptor elements.

[0255] In some embodiments, the susceptor element is arranged to heat the outer surface of the aerosol-forming substrate. In some embodiments, the susceptor element is arranged to be inserted into the aerosol-forming substrate when the aerosol-forming substrate is received within a cavity.

[0256] The susceptor element may comprise any suitable material. The susceptor element may be formed from any material that can be inductively heated to a temperature sufficient to release volatile compounds from the aerosol-forming substrate. Materials suitable for an elongate susceptor element include graphite, molybdenum, silicon carbide, stainless steel, niobium, aluminium, nickel, nickel-containing compounds, titanium, and composites of metallic materials. Some susceptor elements contain metal or carbon. Advantageously, the susceptor element may comprise or consist of a ferromagnetic alloy such as, for example, ferrite iron, ferromagnetic steel or stainless steel, ferromagnetic particles, and ferromagnetic materials such as ferrite. A suitable susceptor element may be or may include aluminium. The susceptor element preferably comprises more than about 5 per cent, preferably more than about 20 per cent, more preferably more than about 50 per cent or more than about 90 per cent of a ferromagnetic or paramagnetic material. Some elongate susceptor elements may be heated to a temperature in excess of about 250 degrees Celsius.

[0257] The susceptor element may comprise a non-metallic core having a metal layer arranged thereon. For example, the susceptor element may include metal tracks formed on the outer surface of a ceramic core or substrate.

[0258] In some embodiments, the aerosol generating device may comprise at least one resistive heating element and at least one inductive heating element. In some embodiments, the aerosol generating device may comprise a combination of a resistive heating element and an inductive heating element.

[0259] The aerosol generating device may comprise a power source. The power source may be a DC power source. In some embodiments, the power source is a battery. The power source may be a nickel-metal hydride battery, a nickel-cadmium battery, or a lithium-based battery (e.g., a lithium cobalt, lithium iron phosphate, or lithium polymer battery). However, in some embodiments, the power source may be another form of charge storage device such as a capacitor. The power source may be required to be rechargeable and may have a capacity that allows for the accumulation of sufficient energy for one or more user operations such as one or more experiences of aerosol generation. For example, the power source may have a capacity sufficient to enable continuous heating of the aerosol-forming substrate for about six minutes, or a multiple of six minutes, corresponding to the typical time taken to smoke a conventional cigarette. In another example, the power source may have a capacity sufficient to enable a predetermined number of smoking sessions, or discontinuous activation of the heater.

[0260] Specific embodiments will be described herein with reference to the figures.

Brief Description of the Drawings

[0261]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Embodiments for Carrying Out the Invention

[0262] Figure 1 illustrates an aerosol generation system 100 including an aerosol generator 10 and an aerosol generation article 1. The aerosol generator 10 includes a housing 4 extending between a mouth-side end 2 and a distal end (not shown). The housing 4 includes a peripheral wall 6. The peripheral wall 6 defines a device cavity for receiving the aerosol generation article 1. The device cavity is defined by a closed distal end and an open mouth-side end. The mouth-side end of the device cavity is located at the mouth-side end of the aerosol generator 10. The aerosol generation article 1 is configured to be received through the mouth-side end of the device cavity and to abut against the closed end of the device cavity.

[0263] An air flow channel 5 is defined within the peripheral wall 6. The air flow channel 5 extends between an inlet 7 located at the mouth-side end of the aerosol generator 10 and an outlet 9 located at a distal position along the peripheral wall 6.

[0264] The aerosol generator 10 further includes a heater (not shown) and a power source (not shown) for supplying power to the heater. A controller (not shown) is also provided to control the power supply to the heater. The heater is configured to heat the aerosol generation article 1 during use when the aerosol generation article 1 is received within the device 10.

[0265] The aerosol generation article 1 includes a first air inlet zone 15 located along a wrapper 22. As shown in FIG. 1, the first air inlet zone 15 includes a row of perforations through the wrapper 22. When the aerosol generation article 1 is received within the device cavity, the outlet 9 is configured to be aligned with or cover the first air inlet zone 15. After being received within the device cavity, the upstream end of the aerosol generation article 1 is disposed to abut against the closed end of the device cavity so that air drawn through the aerosol generator 10 does not flow through the upstream end of the aerosol generation article 1. The air drawn through the aerosol generator 10 can enter the aerosol generation article 1 only through the first air inlet zone 15, as shown in FIG. 1.

[0266] As shown in FIG. 1, the aerosol generating article 1 and the device cavity are arranged to form an airtight fit such that air cannot flow between the peripheral wall 6 and the article 1. This airtight fit is established along most of the total length of the device cavity. The device cavity has a length of about 25 mm.

[0267] As an alternative to defining an airtight fit between the device cavity and the aerosol generating article 1 over its entire length, as shown in FIG. 2, the aerosol generation system 200 may comprise an aerosol generating device 20 having an outer peripheral protrusion 29 extending from the peripheral wall 6 into the device cavity. The outer peripheral protrusion 29 is configured to establish an airtight fit with a portion of the aerosol generating article 1 at a position downstream of the first air inlet zone 15 when received within the aerosol generating device. The inner diameter of the outer peripheral protrusion 29 is arranged to be similar to the diameter of the aerosol generating article 1 in order to define the airtight fit. Thereby, the air drawn through the aerosol generating device 20 can enter the aerosol generating article 1 only via the air flow channel 5 and its outlet 7, ensuring that it does not pass through the gap between the article 1 and the device cavity.

[0268] FIG. 3 is a more detailed view of an aerosol generation system 100 similar to that illustrated in FIG. 1. The air flow channel 5 is defined within the peripheral wall 6. The air flow channel 5 includes a first portion extending axially from the inlet 7 and a second portion extending transversely or radially from the end of the first portion to the outlet 9. As a result, the air flow channel 5 includes an L-shaped bend.

[0269] Figure 4 shows an aerosol generation system 300 similar to that shown in Figure 3. The aerosol generation system 300 includes an aerosol generator 30 and an aerosol generating article 1. The aerosol generator 30 is similar to the aerosol generator 10, but differs in that an air flow channel 205 is defined along the inner surface of the peripheral wall 6. In such an embodiment, a portion of the air flow channel 205 is configured to cover a first air inlet zone 15 of the aerosol generating article 1. The air flow channel 205 has a length of about 23 millimeters. The entire length of the air flow channel 205 is configured to cover the aerosol generating article 1 when received within the device 30.

[0270] Figure 5 shows an aerosol generating article 1 configured for use in the aerosol generation systems 100, 200, 300 shown in Figures 1 - 4.

[0271] The aerosol generating article 1 includes a rod 12 of an aerosol - forming substrate, a hollow support segment 14, an aerosol cooling element (or segment) 16, and a mouthpiece segment 18. The components downstream of the rod 12 of the aerosol - forming substrate (in this case, the hollow support segment 14, the aerosol cooling element 16 and the mouthpiece segment 18) form a downstream section of the aerosol generating article 1. These four elements are arranged in alignment along the major axis from end to end and are surrounded by a wrapper 22 so as to form the aerosol generating article 1. The aerosol generating article 1 shown in Figure 1 is particularly suitable for use with an electrically - operated aerosol generator 1 that includes a heater for heating the rod 12 of the aerosol - forming substrate.

[0272] The rod 12 of the aerosol - forming substrate has a length of about 12 millimeters and a diameter of about 7 millimeters. The rod 12 is of cylindrical shape and has a substantially circular cross - section. The rod 12 includes an assembly of sheets of homogenized tobacco material. The hollow cellulose acetate tube (hollow support segment) 14 has a length of about 8 millimeters and its peripheral wall has a thickness of about 1 millimeter.

[0273] The mouthpiece segment 18 comprises a plug of 8 denier cellulose acetate tow per filament and has a length of about 7 millimeters. The mouthpiece segment 18 has a diameter of about 7 millimeters. The aerosol cooling element 16 has a length of about 18 mm and a diameter of about 7 mm.

[0274] The aerosol generating article 1 comprises a first air inlet zone 15 along the rod of the aerosol-forming substrate, at least about 2 millimeters from the upstream end of the rod 12 of the aerosol-forming substrate. The first air inlet zone 15 is located less than about 10 millimeters from the downstream end of the rod 12 of the aerosol-forming substrate or the upstream end of the hollow support segment 14. The first air inlet zone 15 surrounds the aerosol generating article 1. That is, the first air inlet zone 15 surrounds the entire circumference of the aerosol generating article 1.

[0275] FIG. 6 shows a comparative example of an incompatible aerosol generating article 102 that is used with the aerosol generating device 30 shown in FIG. 4 and that does not have a first air inlet zone located along and around the rod of the aerosol-forming substrate. Since the article 102 does not have an air inlet zone and the upstream end of the article 102 is in contact with the distal end of the device cavity, air is not drawn through the device and the article 102.

[0276] FIG. 7 shows an aerosol generating system 400 similar to the aerosol generating system 300 shown in FIG. 4. The aerosol generating system 400 comprises an aerosol generating device 40 and an aerosol generating article 103. The aerosol generating system 400 differs from the aerosol generating system 300 in that, as shown in FIG. 8, a first air inlet zone 115 is located around the hollow support segment 14 of the aerosol generating article 103. The first air inlet zone 115 is located about 2 mm downstream of the upstream end of the hollow support segment 14 and about 2 mm downstream of the downstream end of the rod 12 of the aerosol-forming substrate, considering that the rod 12 of the aerosol-forming substrate and the hollow support segment 14 are in direct contact.

[0277] As a result of the position of the first air inlet zone 115, the airflow channel 305 defined in the peripheral wall 6 of the aerosol generator 40 is shorter than the airflow channel 5. The length of the airflow channel 305 is from about 11 to about 13 mm.

[0278] FIG. 9 shows an aerosol generation system 500 similar to the aerosol generation system 100. The aerosol generation system 500 includes an aerosol generator 50 and an aerosol article 104, both of which are configured to be used together with each other. The aerosol generator 50 is similar to the aerosol generator 10, but differs in that the device 50 includes an airflow channel 405 including one inlet 7 and two outlets 9, 19. The first outlet 9 of the airflow channel 405 is configured to provide fluid communication between the outside of the aerosol generator 50 and the first air inlet zone 15 of the aerosol article 104. The second outlet 19 of the airflow channel 405 is configured to provide fluid communication between the outside of the aerosol generator 50 and the second air inlet zone 115 of the aerosol article 104.

[0279] FIG. 10 shows an aerosol generation system 600 similar to the aerosol generation system 500. Instead, the aerosol generation system 600 includes an aerosol generator 30 and an aerosol article 104. As described above, the airflow channel 205 is defined along the inner surface of the peripheral wall 6.

[0280] The aerosol article 104 is shown in FIG. 11. The two air inlet zones 15, 115 are located around two different components of the aerosol article 104. The first air inlet zone 15 is disposed along the rod 12 of the aerosol forming substrate at least about 2 mm downstream of the upstream end of the rod 12 of the aerosol forming substrate. The second air inlet zone 115 is disposed along the hollow support segment 14 at least about 2 mm downstream of the rod 12 of the aerosol forming substrate and at least about 2 mm downstream of the upstream end of the hollow support segment 14.

[0281] As shown in both FIGS. 9 and 10, the fluid communication between the exterior of the aerosol generators 30, 40 and the interior of the aerosol article 104 is established via two different air entry zones 15, 115. The first air entry zone 15 is configured to allow more air to pass through than the second air entry zone 115. In other words, the first air entry zone 15 is configured to provide a higher level of air entry than the second air entry zone 115.

[0282] The first air entry zone 15 is configured to be the primary air intake zone of the aerosol article 104 when the article 104 is received within the devices 30, 40 upon contact of the upstream end of the article 104 with the distal end of the device cavity. The second air entry zone 115 is configured to provide ventilation to the article 104, i.e., to ventilate the aerosol flowing through the hollow support segment 14 from the rod 12 of the aerosol-forming substrate towards the mouth-side end of the article 104. The second air entry zone 115 extends around the wrapper 22 and includes a row of perforations that penetrate the peripheral walls of the wrapper 22 and the hollow support segment 14.

[0283] FIG. 12 shows an aerosol generating system 700 comprising the aerosol generator 30 and the aerosol article 105 shown in FIG. 13. The aerosol article 105 comprises two air entry zones 215, 315 separated by a distance of approximately 1.5 mm. The first air entry zone 215 includes the porous portion of the wrapper 22. Such a porous portion forming the first air entry zone 15 has a width of approximately 3 mm. The second air entry zone 315 includes a row of perforations that penetrate the wrapper 22 and extend circumferentially. The second air entry zone 315 is located approximately 1.5 mm downstream of the first air entry zone 215. Both the first air entry zone 215 and the second air entry zone 315 are located along the rod of the aerosol-forming substrate 12. The first air entry zone 215 is located approximately 2 mm downstream of the upstream end of the rod 12 of the aerosol-forming substrate.

[0284] When received within the aerosol generating device 30, the upstream end of the aerosol generating article 105 abuts the distal end of the device cavity in order to prevent air from flowing through the upstream end of the aerosol generating article 105. Thus, in use, air is configured to flow through the first air inlet zone 215 due to an overlap between the airflow channel 205 and the first air inlet zone 215.

[0285] Each of the aerosol generating devices 10, 20, 50 described above comprises two or more airflow channels. The aerosol generating devices 10, 20, 50 shown in FIGS. 1, 2, 3, 6 and 9 comprise at least two elongate airflow channels 5, 405. Each of the aerosol generating devices 30, 40 comprises an annular airflow channel 205, 305 as shown in FIGS. 4, 7, 10 and 12.

[0286] Unless otherwise specified, each of the aerosol generating articles 1, 102, 103, 104, 105 described comprises the same structural components, for example, a rod 12 of the aerosol forming substrate, a hollow support segment 14, an aerosol cooling element 16, and a mouthpiece segment 18 disposed within a wrapper 22, but mainly differs in the configuration of the air inlet zone provided on the article.

Claims

1. An aerosol generating system, comprising: An aerosol generating article, comprising: A rod of an aerosol forming substrate, and A filter positioned downstream of the rod of the aerosol forming substrate, wherein The rod of the aerosol forming substrate and the filter are assembled within a wrapper, and the aerosol generating article includes a first air inlet zone located on the wrapper, and the first air inlet zone is configured to allow air to enter the interior of the aerosol generating article; An aerosol generating device having a distal end and a mouthpiece end, the aerosol generating device comprising: A housing defining a device cavity for removably receiving the aerosol generating article at the mouthpiece end of the device; A heater for heating the aerosol forming substrate when the aerosol generating article is received within the device cavity; and An air flow channel extending between a channel inlet and a channel outlet, the air flow channel being configured to establish fluid communication between the interior of the device cavity and the exterior of the aerosol generating device; The aerosol generating system is configured such that when the aerosol generating article is received within the device cavity, fluid communication between the interior of the aerosol generating article and the exterior of the aerosol generating device is established by fluid communication between the first air inlet zone of the aerosol generating article received within the device cavity and the air flow channel of the aerosol generating device; Further, the aerosol generating device includes a peripheral wall defining the device cavity, and when the aerosol generating article is received within the aerosol generating device, a sealing portion of the peripheral wall is configured to establish an airtight fit with a portion of the aerosol generating article at a position downstream or upstream of the first air inlet zone of the aerosol generating article.

2. The aerosol generating system according to claim 1, wherein the fluid communication between the interior of the aerosol generating article and the exterior of the aerosol generating device is established by an air flow channel outlet of the aerosol generating device covering the first air inlet zone of the aerosol generating article received within the device cavity.

3. The aerosol generating system according to claim 1 or 2, wherein when the aerosol generating article is received in the device cavity, the upstream end of the aerosol generating article is blocked so that air is substantially prevented from entering the aerosol generating article through its upstream end.

4. The aerosol generating system according to any one of claims 1 to 3, wherein the diameter of the device cavity increases in a direction from the sealing portion of the peripheral wall towards the distal end of the device cavity.

5. The aerosol generating device includes a peripheral wall defining the device cavity, the aerosol generating device includes an outer peripheral protrusion extending from the peripheral wall into the device cavity, and when the outer peripheral protrusion is received in the aerosol generating device, it is configured to establish an airtight fit with a portion of the aerosol generating article at a position downstream of the first air entry zone of the aerosol generating article. The aerosol generating system according to any one of claims 1 to 4.

6. The aerosol generating system according to any one of claims 1 to 5, wherein the wrapper of the aerosol generating article includes an air-impermeable material.

7. The aerosol generating system according to any one of claims 1 to 6, wherein the first air entry zone is located along the rod of the aerosol forming substrate.

8. The aerosol generating system according to any one of claims 1 to 7, wherein the first air entry zone is located at least 2 mm downstream of the upstream end of the rod of the aerosol forming substrate.

9. The filter of the aerosol generating article includes a mouthpiece segment including a plug of filtering material disposed downstream of the rod of the aerosol forming substrate, and a hollow tubular segment located between the mouthpiece segment and the rod of the aerosol forming substrate. The aerosol generating system according to any one of claims 1 to 8.

10. The aerosol generating system according to claim 9, wherein the first air entry zone is located along the hollow tubular segment.

11. The aerosol generating system according to any one of claims 1 to 10, wherein the aerosol generating article includes a second air entry zone located on the wrapper at a position downstream of the first air entry zone.

12. The aerosol generation system according to claim 11, wherein the second air entry zone is located at a position at least 1 mm downstream of the rod of the aerosol-forming substrate. **Claim 13** The aerosol generation system according to claim 11 or 12, wherein the level of air entry into the interior of the aerosol-generating article through the first air entry zone is configured to be greater than the level of air entry into the interior of the aerosol-generating article through the second air entry zone. **Claim 14** The aerosol generation system according to any one of claims 1 to 13, wherein the air entry zone includes a plurality of openings passing through the wrapper.

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