Aerosol-generating system having ventilation chamber

Abstract

To provide an aerosol-generating system comprising an aerosol-generating article and an aerosol-generating device.SOLUTION: A rod 12 of an aerosol-forming substrate of an aerosol-generating article 1 and filters 14, 16, 18 are assembled within a wrapper 22. The aerosol-generating article comprises a ventilation zone 26 comprising a plurality of apertures extending through the wrapper. An aerosol-generating device 20 comprises a housing 4 and a heater for heating the aerosol-forming substrate of the aerosol-generating article. The housing comprises a peripheral wall that defines a device cavity for removably receiving the aerosol-generating article at a mouth end 2 of the device. An aerosol-generating system 200 is configured so that, when the aerosol-generating article is received within the device cavity, the ventilation zone of the aerosol-generating article is located within the device cavity and a portion of an internal surface of the peripheral wall overlying the ventilation zone is spaced apart from the aerosol-generating article.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present application relates to an aerosol generating system comprising an aerosol generating device configured to receive an aerosol-generating article. The present application also relates to an aerosol generating device having a vent chamber. [Background technology]

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

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

[0004] However, when an aerosol-generating article having vent openings (referred to as a "vent zone") on its outer wrapper is received within a known aerosol-generating device, such vent openings may be exposed to the environment external to the device. During use of the article within the device, the vent openings may provide beneficial dilution of the aerosol flowing through the article for delivery to the consumer, as well as ventilation of airflow that may reduce the temperature of the generated aerosol.

[0005] Exposed vent openings can result in consumers inadvertently blocking the article's vent openings with their fingers or lips during normal use of the aerosol generation system. Such blocking can then affect the consumer's sensory experience by increasing the effective resistance to drawing the article and preventing optimal aerosol formation and cooling. It would therefore be desirable to provide an aerosol generation system that at least addresses this problem. Summary of the Invention

[0006] Provided herein is an aerosol-generating device configured to receive an aerosol-generating article. The aerosol-generating article may comprise a rod of an aerosol-forming substrate. The aerosol-generating article may comprise a filter assembled within a wrapper. The aerosol-generating article may further comprise a ventilation zone located on the wrapper. The ventilation zone may comprise a plurality of openings extending through the wrapper. The aerosol-generating device may have a distal end and a mouth end. The aerosol-generating device may comprise a housing. The housing may comprise a peripheral wall defining 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 be configured such that when the aerosol-generating article is received within the device cavity, the ventilation zone of the aerosol-generating article is located within the device cavity, and a portion of the interior surface of the peripheral wall above the ventilation zone is spaced apart from the aerosol-generating article.

[0007] According to the present application, there is provided an aerosol-generating system, which may include an aerosol-generating article and an aerosol-generating device. The aerosol-generating article may include a rod of aerosol-forming substrate. The aerosol-generating article may include a filter positioned downstream of the rod of aerosol-forming substrate. The rod of aerosol-forming substrate and the filter may be assembled within a wrapper. The aerosol-generating article may include a ventilation zone located on the wrapper. The ventilation zone may include a plurality of openings extending through the wrapper. The aerosol-generating device may have a distal end and a mouth end. The aerosol-generating device may include a housing. The aerosol-generating device may include a heater for heating the aerosol-forming substrate when the aerosol-generating article is received within the device cavity. The housing may include a peripheral wall. The peripheral wall may define a device cavity for removably receiving the aerosol-generating article at the mouth end of the device. The aerosol-generating system is configured such that when the aerosol-generating article is received within the device cavity, the ventilation zone of the aerosol-generating article is located within the device cavity, and a portion of the inner surface of the peripheral wall above the ventilation zone is spaced apart from the aerosol-generating article.

[0008] According to the present invention, there is provided an aerosol generation system comprising an aerosol-generating article and an aerosol-generating device. The aerosol-generating article comprises a rod of aerosol-forming substrate and a filter positioned downstream of the rod of aerosol-forming substrate. The rod of aerosol-forming substrate and the filter are assembled within a wrapper. The aerosol-generating article comprises a ventilation zone located on the wrapper. The ventilation zone comprises a plurality of openings extending through the wrapper. The aerosol-generating device has a distal end and a mouth end and comprises a housing and a heater for heating the aerosol-forming substrate when the aerosol-generating article is received within the device cavity. The housing comprises a peripheral wall. The peripheral wall defines a device cavity for removably receiving the aerosol-generating article at the mouth end of the device. The aerosol-generating system is configured such that when the aerosol-generating article is received within the device cavity, the ventilation zone of the aerosol-generating article is located within the device cavity and a portion of the interior surface of the peripheral wall above the ventilation zone is separated from the aerosol-generating article.

[0009] The aerosol-generating device of the aerosol-generating system may be configured such that, when the aerosol-generating article is received within the device cavity, the ventilation zone of the aerosol-generating article is located within the device cavity, and a portion of the inner surface of the peripheral wall above the ventilation zone is spaced apart from the aerosol-generating article.

[0010] By providing a portion of the inner surface of the peripheral wall above the ventilation zone from the aerosol-generating article, it is ensured that the ventilation zone of the aerosol-generating article is covered by the housing of the aerosol-generating device and is not exposed to the outside of the device during use of the aerosol-generating system.

[0011] Furthermore, providing such a portion of the interior surface of the peripheral wall spaced apart from the ventilation zone of the article also ensures that air or aerosols can flow between the interior surface of the peripheral wall and the ventilation zone of the article, which means that the ventilation zone may serve the function of providing ventilation to the article without being obscured or blocked off by the consumer.

[0012] The portion of the inner surface of the peripheral wall that is separated from the ventilation zone of the aerosol-generating article may refer to a portion of the inner surface of the peripheral wall that is further separated from the aerosol-generating article than the remainder or other portion of the inner surface of the peripheral wall. In other words, the portion of the inner surface of the peripheral wall that is separated from the ventilation zone of the aerosol-generating article is a portion of the inner surface of the peripheral wall that is further separated from the aerosol-generating article than the remainder or other portion of the inner surface of the peripheral wall. In other words, the portion of the inner surface of the peripheral wall that is separated from the ventilation zone of the aerosol-generating article is a portion of the inner surface of the peripheral wall that is further separated from the aerosol-generating article than the remainder or other portion of the inner surface of the peripheral wall.

[0013] As used herein, the term "aerosol-generating device" refers to a device that includes a heater element that interacts with an aerosol-generating substrate of an aerosol-generating article to generate an aerosol.

[0014] As used herein, the term "longitudinal" refers to a 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 device.

[0015] As used herein, the terms "upstream" and "downstream" describe the relative location of an aerosol-generating article or element or portion of an element of a device with respect to the direction in which aerosol is transported through the aerosol-generating article during use.

[0016] In use, air is drawn through the aerosol-generating article in the longitudinal direction. The term "transverse" refers to a direction perpendicular to the longitudinal axis. Any reference to a "cross section" of an aerosol-generating article or a component of an aerosol-generating article refers to a transverse cross section, unless otherwise specified.

[0017] The term "length" refers to the dimension of an aerosol-generating article or device component along its longitudinal axis.

[0018] As used herein, the term "homogenized tobacco material" encompasses any tobacco material formed by agglomeration of particles of tobacco material. A sheet or web of homogenized tobacco material is formed by agglomerating particulate tobacco obtained by grinding or otherwise pulverizing one or both of tobacco lamina and tobacco stem. In addition, the homogenized tobacco material may contain one or more small amounts of tobacco dust, tobacco fines, and other particulate tobacco by-products formed during tobacco processing, handling, and shipping. A sheet of homogenized tobacco material may be produced by casting, extrusion, a papermaking process, or any other suitable process known in the art.

[0019] The term "porous" is used herein to refer to a material that provides a plurality of pores or openings that allow the passage of air through the material.

[0020] The term "ventilation level" may be used throughout this specification to mean the volume ratio of the airflow entering the aerosol-generating article via the ventilation zone (ventilation airflow) to the sum of the aerosol airflow and the ventilation airflow. The greater the ventilation level, the greater the dilution of the aerosol stream delivered to the consumer. 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.

[0021] The aerosol-generating article of the present invention comprises a rod of an aerosol-forming substrate. The aerosol-generating article may further comprise a downstream section located downstream of the rod of the aerosol-forming substrate. Such a downstream section may be considered the filter of the aerosol-generating article. The filter (or downstream section of the article) or mouthpiece segment may comprise a plug of filtration material and a hollow tubular segment located between the rod of the aerosol-forming substrate and the mouthpiece segment. All three elements are preferably longitudinally aligned. The rod of the aerosol-forming substrate preferably comprises at least an aerosol former. In some embodiments, the aerosol-generating article according to the present invention may comprise an additional support element (or support segment) positioned between the rod of the aerosol-forming substrate and the hollow tubular segment in longitudinal alignment with them. More particularly, the support element (or support segment) is preferably provided immediately downstream of the rod and immediately upstream of the hollow tubular element (or segment). The additional support element or segment may be tubular.

[0022] The ventilation zone of the aerosol-generating article can be located anywhere along the article. The ventilation zone can be located downstream of the rod of the aerosol-forming substrate. The ventilation zone can be located along the hollow tubular segment of the filter or mouthpiece segment of the article. The ventilation zone can be located along the plug of filtration material of the filter (or mouthpiece segment) of the article.

[0023] The phrase "received within" may refer to the fact that a component or element is completely or partially received within another component or element. For example, the phrase "an aerosol-generating article is received within a device cavity" refers to the aerosol-generating article being completely or partially received 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 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.

[0024] The length of the device cavity may be about 10 mm to about 50 mm. The length of the device cavity may be about 20 mm to about 40 mm. The length of the device cavity may be about 25 mm to about 30 mm.

[0025] A space defined by a portion of the interior surface of the peripheral wall may define a vent chamber within the peripheral wall. The vent chamber may be configured to be in fluid communication with the exterior of the aerosol-generating device and the ventilation zone of the aerosol-generating article. Preferably, the vent chamber is defined within the thickness of the peripheral wall. In other words, the vent chamber may be defined on a surface (e.g., an interior or internal surface) of the peripheral wall or within the thickness of the peripheral wall, at a location between the inner longitudinal surface and the outer longitudinal surface of the peripheral wall.

[0026] When the aerosol-generating article is received within the device cavity, the article's ventilation zone is aligned with and positioned so as to be surrounded by the ventilation chamber defined within the device. This ensures that during normal use of the aerosol-generating system, the ventilation zone of the aerosol-generating article is covered by the housing of the aerosol-generating device, and therefore the ventilation zone is not exposed to the exterior of the device. It also ensures that air or aerosol can flow between the device's ventilation chamber and the article's ventilation zone. This means that the ventilation zone may serve the function of providing ventilation to the article without being obscured or blocked by the consumer's mouth or fingers during normal use.

[0027] The vent chamber may be adjacent to the oral end of the aerosol generating device. The vent chamber may extend from the oral end of the aerosol generating device. In such embodiments, the vent chamber may be in direct fluid communication with the outside of the aerosol generating device. The term "direct fluid communication" refers to the fact that no other element or airflow path is required for fluid (air) to communicate with the vent chamber. For example, when the vent chamber is in direct fluid communication with the outside of the aerosol generating device, it means that air from the outside of the aerosol generating device directly enters the vent chamber. In other words, when air leaves the vent chamber, it reaches the outside of the aerosol generating device directly. Preferably, the vent chamber is configured to be in fluid communication with the outside of the aerosol generating device via the oral end of the aerosol generating device. Preferably, the vent chamber is configured to be in fluid communication with the outside of the aerosol generating device via the oral end surface of the aerosol generating device. In other words, it is preferred that air enter the vent chamber via the oral end or oral end surface of the aerosol generating device.

[0028] Locating the vent chamber adjacent to the mouth end ensures that, when the article includes a ventilation zone, air can flow into the vent chamber to provide fluid communication between the aerosol-generating article and its ventilation zone. The vent chamber may have two ends, a first end and a second end. The second end of the vent chamber may be located closer to the mouth end of the aerosol-generating device than the first end of the vent chamber. The second or proximal end of the vent chamber may be located at the mouth end of the aerosol-generating device. In such embodiments, the second end of the vent chamber may be open, and the first end of the vent may be closed. Having the second end of the vent chamber open allows air to easily enter the vent chamber while also ensuring that the ventilation zone of the aerosol-generating article is hidden from the user during normal use.

[0029] In embodiments where the second end of the vent chamber is not located at the oral end of the aerosol-generating device, the second end of the vent chamber may be located at least about 1 mm from the oral end (face) of the aerosol-generating device (or the open end of the device cavity). The second end of the vent chamber may be located at least about 2 mm from the oral end (face) of the aerosol-generating device. The second end of the vent chamber may be located at least about 3 mm from the oral end (face) of the aerosol-generating device.

[0030] The first end of the vent chamber can be located at least about 10 mm from the distal end of the device cavity. The first end of the vent chamber can be located at least about 20 mm from the distal end of the device cavity. The first end of the vent chamber can be located at least about 30 mm from the distal end of the device cavity.

[0031] The term "oral end" refers to the portion of an element or component that is configured to be placed in or near a user's mouth during normal use of the element or component. The oral end may also correspond to the downstream end. For example, the oral end of an aerosol-generating article may also be the downstream end of the article. The oral end of an aerosol-generating article or device is configured to be placed in or near a consumer's mouth during normal use. The oral end of an aerosol-generating device may also be referred to as the proximal end of the aerosol-generating device. The oral end of an aerosol-generating device may refer to the oral end face of the aerosol-generating device that is configured to receive the aerosol-generating article. Thus, the open end of the device cavity may be defined in the oral end face of the aerosol-generating device.

[0032] In some embodiments, the vent chamber may be located longitudinally away from the mouth end of the aerosol generating device.

[0033] In this context, the expression "a longitudinal position away from the mouth end of the aerosol-generating device" refers to a longitudinal position that is not located at the mouth end of the aerosol-generating device. Thus, a longitudinal position away from the mouth end of the aerosol-generating device refers to a longitudinal position that is different from (or at a distance from) the longitudinal position of the mouth end of the aerosol-generating device.

[0034] By providing a vent chamber away from the mouth end of the aerosol-generating device, the vent chamber can form a cavity or space around the aerosol-generating article received within the cavity of the device, away from the mouth end. When the aerosol-generating article is received with the article, such a vent chamber is in fluid communication with the exterior of the aerosol-generating article. The exterior of the aerosol-generating article can be defined by a wrapper. The wrapper can be porous. The wrapper can be sufficiently porous to allow air from the vent chamber to enter the aerosol-generating article. By allowing air to enter, the vent chamber can promote cooling of the article, thereby enhancing nucleation of aerosol particles within the article. The vent chamber may be more likely to promote nucleation when located longitudinally away from the mouth end. This is because the vent chamber is more likely to overlap with a more upstream portion of the aerosol-generating article, closer to where aerosol generation occurs. Thus, such positioning of the vent chamber can improve aerosol delivery to the consumer.

[0035] In such embodiments, the vent chamber has two ends, a first end and a second end. The second end of the vent chamber is closer to the mouth end of the device than the first end of the vent chamber. In such embodiments, both ends of the vent chamber are located away from the mouth end of the aerosol generating device. In other words, the second end is not located at the mouth end of the device.

[0036] In such embodiments, air can flow from the exterior of the device to the vent chamber through a gap or space provided between the peripheral wall and the aerosol-generating article when received within the device cavity and extending between the vent chamber and the mouth end of the device.

[0037] In embodiments in which the vent chamber is located at a longitudinal position away from the mouth end of the aerosol generating device, the vent chamber may be configured to be in fluid communication with the exterior of the aerosol generating device through a chamber inlet defined in the housing.

[0038] The chamber inlet may be a separate element from the device cavity. In other words, the chamber inlet may not be defined by the device cavity, but instead may be defined within the housing. The chamber inlet may be defined within a peripheral wall defining the device cavity. Preferably, the chamber inlet is defined within the thickness of the peripheral wall or on the peripheral wall. In other words, the chamber inlet may be defined on a surface (e.g., an interior or inner surface) of the peripheral wall or within the thickness of the peripheral wall, at a position between the inner longitudinal surface and the outer longitudinal surface of the peripheral wall.

[0039] The chamber inlet allows fluid communication between the exterior of the aerosol-generating device and the vent chamber, whereby air from outside the device can be in fluid communication with the wrapper of the aerosol-generating article when received within the device. Such fluid communication enhances aerosol generation by promoting nucleation and cooling of the generated aerosol within the article.

[0040] When the aerosol-generating article has a ventilation zone on the wrapper, air entering the ventilation chamber from outside the aerosol-generating device through the chamber inlet can pass through the ventilation zone in the article, providing ventilation for the aerosol-generating article.

[0041] Furthermore, in embodiments in which the vent chamber is located longitudinally away from the mouth end of the aerosol-generating device, generated aerosol may accumulate within the vent chamber. Such aerosol accumulation may enhance the consumer experience by providing a supplemental aerosol source that the consumer can inhale.

[0042] In some embodiments, the chamber inlet may extend between the vent chamber and the mouth end of the aerosol generating device, thereby allowing air to flow from outside the device through the chamber inlet and into the vent chamber.

[0043] The chamber inlet may extend along any direction from the vent chamber to establish a fluid connection between the vent chamber and the exterior of the device. The chamber inlet may extend along a direction substantially parallel to the longitudinal axis of the aerosol-generating device. The chamber inlet may extend along a direction substantially perpendicular to the longitudinal axis of the aerosol-generating device.

[0044] The chamber inlet may have a circular cross-section. The chamber inlet may have an annular cross-section. The chamber inlet may have a cross-section in the shape of an annular sector. "Annular sector" refers to a portion or section of an annular shape or ring.

[0045] The chamber inlet and the vent chamber may have the same cross-sectional shape. For example, the vent chamber may be annular, and the chamber inlet may be annular. For example, the vent chamber may be circular, and the chamber inlet may also be circular. Alternatively, the chamber inlet and the vent chamber may have different cross-sectional shapes. For example, the chamber inlet may be circular, and the vent chamber may be annular.

[0046] The chamber inlet may have a cross-sectional area that is smaller than the cross-sectional area of the vent chamber. The cross-sectional area of the chamber inlet may vary along the longitudinal axis.

[0047] The chamber inlet may be cylindrical or conical.

[0048] The chamber inlet may have a cross-sectional area of about 75 percent or less of the cross-sectional area of the vent chamber. The chamber inlet may have a cross-sectional area of about 50 percent or less of the cross-sectional area of the vent chamber. The chamber inlet may have a cross-sectional area of about 25 percent or less of the cross-sectional area of the vent chamber. The chamber inlet may have a cross-sectional area of about 20 percent or less of the cross-sectional area of the vent chamber. The chamber inlet may have a cross-sectional area of about 10 percent or less of the cross-sectional area of the vent chamber. The chamber inlet may have a cross-sectional area of about 5 percent or less of the cross-sectional area of the vent chamber.

[0049] The diameter of the chamber inlet may be about 0.1 mm or more. The diameter of the chamber inlet may be about 0.2 mm or more. The diameter of the chamber inlet may be about 0.5 mm or more.

[0050] The diameter of the chamber inlet may be about 2 mm or less. The diameter of the chamber inlet may be about 1.5 mm or less. The diameter of the chamber inlet may be about 1 mm or less.

[0051] The diameter of the chamber inlet may be about 0.1 mm to about 2 mm. The diameter of the chamber inlet may be about 0.2 mm to about 1.5 mm. The diameter of the chamber inlet may be about 0.5 mm to about 1 mm.

[0052] The ratio of the diameter of the chamber inlet to the depth of the vent chamber may be about 30 or less. The ratio of the diameter of the chamber inlet to the depth of the vent chamber may be about 20 or less. The ratio of the diameter of the chamber inlet to the depth of the vent chamber may be about 15 or less.

[0053] The ratio of the chamber inlet diameter to the vent chamber depth may be greater than or equal to about 2. The ratio of the chamber inlet diameter to the vent chamber depth may be greater than or equal to about 5. The ratio of the chamber inlet diameter to the vent chamber depth may be greater than or equal to about 10.

[0054] The ratio of the chamber inlet diameter to the vent chamber depth may range from about 2 to about 30. The ratio of the chamber inlet diameter to the vent chamber depth may range from about 5 to about 20. The ratio of the chamber inlet diameter to the vent chamber depth may range from about 10 to about 15.

[0055] When the depth of the vent chamber varies, the depth of the vent chamber may refer to the average depth of the vent chamber. When the diameter of the chamber inlet varies, the diameter of the chamber inlet may refer to the average diameter of the chamber inlet.

[0056] The length of the chamber inlet may be about 1 mm or more. The length of the chamber inlet may be about 2 mm or more. The length of the chamber inlet may be about 3 mm or more.

[0057] The length of the chamber inlet may be about 15 mm or less. The length of the chamber inlet may be about 10 mm or less. The length of the chamber inlet may be about 6 mm or less. The length of the chamber inlet may be about 4 mm or less.

[0058] The length of the chamber inlet may be about 1 mm to about 15 mm. The length of the chamber inlet may be about 1 mm to about 6 mm. The length of the chamber inlet may be about 2 mm to about 6 mm. The length of the chamber inlet may be about 3 mm to about 4 mm.

[0059] The length of the chamber inlet may define the distance of the vent chamber from the oral end of the aerosol generating device.

[0060] There may be multiple chamber inlets, and in such embodiments, the chamber inlets may be evenly and radially distributed at the oral end of the device.

[0061] In some embodiments, the thickness of the portion of the peripheral wall that defines the vent chamber may differ from the thickness of different portions of the peripheral wall.

[0062] In some embodiments, the thickness of the portion of the peripheral wall that defines the vent chamber may be less than the thickness of a different portion of the peripheral wall, hi some embodiments, the thickness of the portion of the peripheral wall that defines the vent chamber may be less than the thickness of the remainder of the peripheral wall.

[0063] In some embodiments, the thickness of the portion of the peripheral wall defining the vent chamber may vary along the longitudinal axis. In such embodiments, the portion of the peripheral wall defining the vent chamber may decrease toward the mouth end of the aerosol generating device. In such embodiments, the portion of the peripheral wall defining the vent chamber may increase toward the mouth end of the aerosol generating device.

[0064] The variation in thickness of the peripheral wall allows for the definition of a vent chamber within the peripheral wall of the device cavity. Such a variation or difference in thickness provides a space between the aerosol-generating article received within the device and the peripheral wall of the device cavity, which in turn allows air to flow between the peripheral wall and the received article. This allows the air flow to reach the ventilation zone or wrapper of the article to provide a ventilation or cooling effect to the aerosol.

[0065] The vent chamber may be annular. The vent chamber may be a continuous annular chamber defined within the peripheral wall of the device housing. This allows the vent chamber to surround the entire wrapper or vent zone of the received article, thereby maximizing the amount of overlap between the vent chamber and the vent zone of the received aerosol-generating article. The greater the overlap, the greater the ventilation provided to the aerosol-generating article received within the device. Furthermore, an annular vent chamber may be simple and efficient to manufacture.

[0066] The vent chamber may have a longitudinal cross-section that is square, rectangular, or triangular.

[0067] The vent chamber may be an annular portion (or sector) that partially surrounds the wrapper or vent zone of the received aerosol-generating article. The aerosol-generating device may include multiple vent chambers. Such multiple vent chambers may include multiple vent chambers located at different longitudinal positions or multiple vent chambers located at different circumferential positions.

[0068] The length of the vent chamber may be about 8 mm or less. The length of the vent chamber may be about 4 mm or less. The length of the vent chamber may be about 3 mm or less.

[0069] The length of the vent chamber may be about 1 mm or more. The length of the vent chamber may be about 2 mm or more. The length of the vent chamber may be about 1 mm or more.

[0070] The length of the vent chamber may be about 1 mm to about 8 mm. The length of the vent chamber may be about 2 mm to about 4 mm. The length of the vent chamber may be about 3 mm to about 4 mm.

[0071] The length of the vent chamber may be at least about 2.5 percent of the length of the device cavity. The length of the vent chamber may be at least about 5 percent of the length of the device cavity. The length of the vent chamber may be at least about 7.5 percent of the length of the device cavity. The length of the vent chamber may be at least about 10 percent of the length of the device cavity.

[0072] The length of the vent chamber may be less than about 40 percent of the length of the device cavity. The length of the vent chamber may be less than about 30 percent of the length of the device cavity. The length of the vent chamber may be less than about 25 percent of the length of the device cavity. The length of the vent chamber may be less than about 20 percent of the length of the device cavity. The length of the vent chamber may be less than about 15 percent of the length of the device cavity.

[0073] The length of the vent chamber may be about 2.5 percent to about 40 percent of the length of the device cavity. The length of the vent chamber may be about 5 percent to about 30 percent of the length of the device cavity. The length of the vent chamber may be about 7.5 percent to about 25 percent of the length of the device cavity.

[0074] By providing a relatively short or small vent chamber, a relatively shorter or smaller overlap between the aerosol-generating article and the vent chamber of the aerosol-generating device can be achieved. As a result, a more targeted, localized portion of the aerosol-generating article can be cooled when received within the device, and therefore the cooling effect resulting from the cooled air entering the vent chamber can be more effective on that portion of the article.

[0075] The depth of the vent chamber refers to the radial distance that the vent chamber extends to the peripheral wall of the device housing. The depth of the vent chamber may be about 3 mm or less. The depth of the vent chamber may be about 2 mm or less. The depth of the vent chamber may be about 1.5 mm or less.

[0076] The depth of the vent chamber may be about 0.5 mm or more. The depth of the vent chamber may be about 1 mm or more.

[0077] The depth of the vent chamber may be from about 0.5 mm to about 3 mm. The depth of the vent chamber may be from about 1 mm to about 2 mm.

[0078] The cross-sectional area of the vent chamber may be about 5 square mm or more. The cross-sectional area of the vent chamber may be about 20 square mm or more. The cross-sectional area of the vent chamber may be about 50 square mm or more.

[0079] The cross-sectional area of the vent chamber may be about 275 mm 2 or less. The cross-sectional area of the vent chamber may be about 150 mm 2 or less.

[0080] The cross-sectional area of the vent chamber may be from about 5 mm 2 to about 275 mm 2. The cross-sectional area of the vent chamber may be from about 20 mm 2 to about 150 mm 2 .

[0081] The peripheral wall of the aerosol generation device housing defining the device housing may have a thickness of about 1 mm or more. The peripheral wall may have a thickness of about 2 mm or more. The peripheral wall may have a thickness of about 3 mm or more.

[0082] The peripheral wall of the aerosol generation device housing defining the device housing may have a thickness of about 10 mm or less. The peripheral wall may have a thickness of about 7.5 mm or less. The peripheral wall may have a thickness of about 5 mm or less.

[0083] The peripheral wall of the aerosol-generating device housing that defines the device housing may have a thickness of about 1 mm to about 10 mm. The peripheral wall may have a thickness of about 2 mm to about 7.5 mm. The peripheral wall may have a thickness of about 3 mm to about 5 mm.

[0084] The depth of the vent chamber may be about 75 percent or less of the thickness of the peripheral wall. The depth of the vent chamber may be about 50 percent or less of the thickness of the peripheral wall. The depth of the vent chamber may be about 35 percent or less of the thickness of the peripheral wall.

[0085] The depth of the vent chamber may be about 10 percent or more of the thickness of the peripheral wall. The depth of the vent chamber may be about 20 percent or more of the thickness of the peripheral wall. The depth of the vent chamber may be about 25 percent or more of the thickness of the peripheral wall.

[0086] The depth of the vent chamber may be about 10 percent to about 75 percent of the thickness of the peripheral wall. The depth of the vent chamber may be about 20 percent to about 50 percent of the thickness of the peripheral wall. The depth of the vent chamber may be about 25 percent to about 35 percent of the thickness of the peripheral wall.

[0087] The aerosol generating device may include an extractor for extracting an aerosol-generating article received within the aerosol generating device, the extractor being configured to be movable within the device cavity.

[0088] The extractor is configured to expose the vent chamber when the extractor is in an operative position, the operative position being defined by the heater contacting the aerosol-forming substrate of the aerosol-generating article.

[0089] 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 comprises 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 may surround the aerosol-generating article when received within the extractor. In such embodiments in which an extractor is present, the peripheral wall of the extractor body may define a vent chamber. Alternatively, the peripheral wall of the device housing may define the vent chamber.

[0090] The extractor may be sized such that, in the operative position, the container body extends between the first end of the vent chamber and the distal end of the device cavity, thereby allowing the aerosol-generating article to be directly exposed to the vent chamber without the extractor body obscuring fluid communication between the vent chamber and the aerosol-generating article.

[0091] The extractor can be sized so that, in the operating position, the container body extends between the mouth end of the device cavity and the distal end of the device cavity. In such embodiments, the extractor body can have a cutout or cutouts to expose the vent chamber to the aerosol-generating article when inserted. The extractor body and device cavity can together be configured to ensure alignment of the cutout or cutouts with the vent chamber or chambers during use. For example, the extractor body can include a protrusion arranged to cooperate with a slot or groove located in the housing of the aerosol-generating device.

[0092] The aerosol-generating device may include an elongated heater arranged to be inserted into the aerosol-generating article when the aerosol-generating article is received in the device cavity. The elongated heater may be arranged with the device cavity. The elongated heater may extend into the device cavity. Alternative heating arrangements are discussed further below. However, in such embodiments in which the heater extends into the device cavity, the extractor body includes an opening in the end wall to allow the heater to extend into the aerosol-generating article. Such an opening may allow 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, a further opening may be provided to allow air to enter the interior of the extractor cavity.

[0093] 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 operative position (when the extractor abuts the distal end of the device cavity), the vent chamber may be defined by a portion of the peripheral wall of the device housing that does not surround the extractor. This portion of the peripheral wall defines the vent chamber when the extractor is in the operative position. Effectively, this portion of the peripheral wall of the device housing may extend longitudinally beyond the extractor to define the vent chamber. The space or gap between the aerosol-generating article and the peripheral wall of the device housing defines the vent chamber.

[0094] An airflow path may be defined to allow fluid communication between the aerosol-forming substrate of an aerosol-generating article received within the device cavity and the exterior of the aerosol-generating device. This airflow path allows aerosol formation when a user inhales the aerosol-generating article while it is being heated within the aerosol-generating device. Air from the airflow path may flow to the upstream end of the aerosol-generating article and through the aerosol-forming substrate of the article. Such an airflow path may be defined within the aerosol-generating device.

[0095] In embodiments in which an extractor is provided, an airflow path may be defined between a peripheral wall of the aerosol generating device housing and an exterior surface of the extractor, the vent chamber being in fluid communication with the airflow path.

[0096] In embodiments where an extractor is not provided, the airflow path may be defined within the thickness of the peripheral wall of the aerosol generating device housing. The airflow path may also be in fluid communication with the vent chamber.

[0097] The filter of the aerosol-generating article may comprise a mouthpiece segment comprising a plug of filtration material positioned 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, with the ventilation zone located along the upstream half of the hollow tubular segment.

[0098] The term "upstream half" refers to the region or portion of the element between the upstream end of the element and the midpoint of the element.

[0099] The aerosol-generating article may include a ventilation zone located less than about 18 millimeters (mm) along the hollow tubular segment from the upstream end of the hollow tubular segment. The distance between the ventilation zone and the upstream end of the hollow tubular segment may be less than about 15 millimeters. Even more preferably, the distance between the ventilation zone and the upstream end of the hollow tubular segment is less than about 10 millimeters.

[0100] Additionally or alternatively, the distance between the ventilation zone and the upstream end of the hollow tubular segment may be at least about 2 millimeters. The distance between the ventilation zone and the upstream end of the hollow tubular segment may be at least about 4 millimeters. The distance between the ventilation zone and the upstream end of the hollow tubular segment may be at least about 6 millimeters.

[0101] The ventilation zone may be provided along the hollow tubular segment at least about 2 millimeters from the upstream end of the mouthpiece. Preferably, the ventilation zone is provided along the hollow tubular segment at least about 4 millimeters from the upstream end of the mouthpiece. Preferably, the ventilation zone is provided along the hollow tubular segment at least about 5 millimeters from the upstream end of the mouthpiece. Even more preferably, the ventilation zone is provided along the hollow tubular segment at least about 6 millimeters from the upstream end of the mouthpiece.

[0102] When the mixture of air and aerosol particles flowing through the aerosol-generating article reaches the ventilation zone, ambient air drawn into the hollow tubular segment through the ventilation zone mixes with the aerosol. This rapidly reduces the temperature of the aerosol mixture while partially diluting the mixture. By providing the ventilation zone at a distance from the upstream end of the mouthpiece segment that falls within the aforementioned range, a cooling chamber is effectively provided immediately upstream of the mouthpiece, advantageously favoring the nucleation and growth of aerosol particles. In this way, the dilution effect of the ventilation air entering the hollow tubular segment is at least partially counteracted, which advantageously allows for a satisfactory aerosol delivery level for consumers.

[0103] The ventilation zone may be provided along the hollow tubular segment at a location at least about 10 millimeters from the downstream end of the mouthpiece segment. The ventilation zone may be provided along the hollow tubular segment at a location at least about 12 millimeters from the downstream end of the mouthpiece segment. The ventilation zone may be provided along the hollow tubular segment at a location at least about 15 millimeters from the downstream end of the mouthpiece segment. This is advantageous in ensuring that the ventilation zone is not blocked by the consumer's lips during use.

[0104] In some embodiments, a ventilation zone is provided along the hollow tubular segment from about 10 millimeters to about 25 millimeters from the downstream end of the mouthpiece segment, more preferably from about 12 millimeters to about 20 millimeters from the downstream end of the mouthpiece segment. In an exemplary embodiment, a ventilation zone is provided along the hollow tubular segment from about 18 millimeters from the downstream end of the mouthpiece segment. In another exemplary embodiment, a ventilation zone is provided along the hollow tubular segment from about 13 millimeters from the downstream end of the mouthpiece segment.

[0105] Without wishing to be bound by theory, it has been found that the temperature reduction caused by admitting cooler outside air into the hollow tubular segment through the ventilation zone can have a beneficial effect on aerosol particle nucleation and growth.

[0106] In this scenario (when the scenario is further complicated by fusion phenomena), the temperature and rate of cooling may play an important role in determining how the system responds. In general, because the nucleation process is typically nonlinear, different cooling rates may lead to significantly different temperature behaviors with respect to the formation of the liquid phase (droplets). Without wishing to be bound by theory, it is hypothesized that cooling can cause a rapid increase in the number of condensed droplets, followed by a short-term, strong increase in this growth (nucleation burst). This nucleation burst appears to be more pronounced at lower temperatures. Furthermore, it appears that a faster cooling rate may favor the onset of early nucleation. In contrast, a decrease in the cooling rate appears to have a favorable effect on the final size that the aerosol droplets ultimately reach.

[0107] Thus, the rapid cooling induced by admitting ambient air into the hollow tubular segment through the ventilation zone can be used to favor favorable nucleation and growth of aerosol droplets. At the same time, however, admitting ambient air into the hollow tubular segment has the direct drawback of diluting the aerosol stream delivered to the consumer.

[0108] Additionally, it has been discovered that in aerosol-generating articles according to the present invention, the cooling and dilution effect caused by the introduction of ventilation air at locations along the conduit defined by the hollow tubular segments described above has a surprising reducing effect on the generation and delivery of phenol-containing species.

[0109] The ventilation zone may comprise one or more rows of apertures or perforations extending through the wrapper of the aerosol-generating article. The apertures or perforations in the ventilation zone may extend through the filter of the aerosol-generating article.

[0110] The ventilation zone may be located at a position along the rod of the aerosol-forming substrate. The ventilation zone may be located at a position downstream of the rod of the aerosol-forming substrate. The ventilation zone may be located at a position along the hollow tubular segment. The ventilation zone may be located at a position along the support segment. The ventilation zone may be located at a position along the mouthpiece segment. The opening of the ventilation zone may extend through the hollow tubular segment, the support segment, or the mouthpiece segment, depending on where the ventilation zone is located.

[0111] The ventilation zone may be located along the hollow tubular segment, and the openings or perforations of the ventilation zone may extend through the peripheral wall of the hollow tubular segment. This is understood to be advantageous in that aerosol nucleation may potentially be further enhanced by condensing the cooling effect provided by the ventilation across the short portion of the cavity defined by the hollow tubular segment. This is because the faster and more dramatic cooling of the stream of species volatilized from the aerosol-forming substrate is expected to be particularly favorable to the formation of new nuclei of aerosol particles.

[0112] The ventilation zone may have only one row of openings or perforations. The row of openings or perforations may have 8 to 30 openings or perforations. The ventilation zone may surround the aerosol-generating article. The ventilation zone may surround the rod of the aerosol-forming substrate. The ventilation zone may surround the hollow tubular segment. The ventilation zone may surround the support segment. The ventilation zone may surround the mouthpiece segment.

[0113] The ventilation 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 that enters the hollow tubular segment when a consumer draws on the mouthpiece of the aerosol-generating article during use. This advantageously allows the ventilation level of the aerosol-generating article to be adjusted.

[0114] The vent perforations can be formed using any suitable technique, such as by laser techniques, mechanical perforation of the hollow tubular segment as part of the aerosol-generating article, or pre-perforation of the hollow tubular segment before it is combined with other elements to form the aerosol-generating article. Preferably, the vent perforations are formed by online laser perforation.

[0115] In an aerosol-generating article according to the present invention, the overall resistance to draw (RTD) of the article essentially depends on the RTD of the rod of the aerosol-forming substrate and the RTD of the mouthpiece segment of the filter, since the hollow tubular segment is substantially empty and therefore only contributes substantially insignificantly to the overall RTD. In practice, the hollow tubular segment may be adapted to generate an RTD in the range of approximately 0 millimeters of HO (approximately 0 Pa) to approximately 20 millimeters of HO (approximately 200 Pa). The hollow tubular segment may be adapted to generate an RTD in the range of approximately 0 millimeters of HO (approximately 0 Pa) to approximately 10 millimeters of HO (approximately 100 Pa).

[0116] The aerosol-generating article may have an overall RTD of less than about 90 millimeters of H2O (about 900 Pa). The aerosol-generating article may have an overall RTD of less than about 80 millimeters of H2O (about 800 Pa). The aerosol-generating article may have an overall RTD of less than about 70 millimeters of H2O (about 700 Pa).

[0117] Additionally, or alternatively, the aerosol-generating article may have an overall RTD of at least about 30 millimeters HO (about 300 Pa). The aerosol-generating article may have an overall RTD of at least about 40 millimeters HO (about 400 Pa). The aerosol-generating article may have an overall RTD of at least about 50 millimeters HO (about 500 Pa).

[0118] The RTD of an aerosol-generating article may be evaluated as the negative pressure that must be applied to the downstream end of the mouthpiece to maintain a steady volumetric flow rate of 17.5 ml / s of air through the mouthpiece under test conditions as defined in ISO 3402. The RTD values listed above are intended to be measured on the aerosol-generating article on its own (i.e., before inserting the article into an aerosol-generating device), without sealing off the ventilation zone perforations.

[0119] The distance between the ventilation zone and the upstream end of the aerosol-generating article may be less than about 50 millimeters. The distance between the ventilation zone and the upstream end of the aerosol-generating article may be less than about 45 millimeters. The distance between the ventilation zone and the upstream end of the aerosol-generating article may be less than about 40 millimeters.

[0120] The distance between the ventilation zone and the upstream end of the aerosol-generating article may be at least about 12 millimeters. The distance between the ventilation zone and the upstream end of the aerosol-generating article may be at least about 15 millimeters. The distance between the ventilation zone and the upstream end of the aerosol-generating article may be at least about 20 millimeters. In some embodiments, the distance between the ventilation zone and the upstream end of the aerosol-generating article may be at least about 25 millimeters.

[0121] The distance between the ventilation zone and the downstream end of the rod of the aerosol-forming substrate may be at least about 2 millimeters. The distance between the ventilation zone and the downstream end of the rod of the aerosol-forming substrate may be at least about 5 millimeters. The distance between the ventilation zone and the downstream end of the rod of the aerosol-forming substrate may be at least about 10 millimeters. In some embodiments, the distance between the ventilation zone and the downstream end of the rod of the aerosol-forming substrate may be at least about 15 millimeters.

[0122] The distance between the ventilation zone and the downstream end of the rod of the aerosol-forming substrate may be less than about 35 millimeters. The distance between the ventilation zone and the downstream end of the rod of the aerosol-forming substrate may be less than about 30 millimeters. The distance between the ventilation zone and the downstream end of the rod of the aerosol-forming substrate may be less than about 25 millimeters.

[0123] The rod of the aerosol-generating substrate preferably has an outer diameter approximately equal to the outer diameter of the aerosol-generating article.

[0124] The aerosol-generating substrate rod preferably has an outer diameter of at least about 5 millimeters. The aerosol-generating substrate rod may have an outer diameter of about 5 millimeters to about 12 millimeters, for example, about 5 millimeters to about 10 millimeters, or about 6 millimeters to about 8 millimeters. In one preferred embodiment, the aerosol-generating substrate rod has an outer diameter of 7.2 millimeters within ±10 percent.

[0125] The aerosol-generating substrate rod may have a length of about 5 millimeters to about 100 mm. Preferably, the aerosol-generating substrate rod has a length of at least about 5 millimeters, and more preferably at least about 7 millimeters. Additionally or alternatively, the aerosol-generating substrate rod preferably has a length of less than about 80 millimeters, more preferably less than about 65 millimeters, and even more preferably less than about 50 millimeters. In a particularly preferred embodiment, the aerosol-generating substrate rod has a length of less than about 35 millimeters, more preferably less than 25 millimeters, and even more preferably less than about 20 millimeters. In one embodiment, the aerosol-generating substrate rod may have a length of about 10 millimeters. In one preferred embodiment, the aerosol-generating substrate rod has a length of about 12 millimeters.

[0126] Preferably, the rod of aerosol-generating substrate has a substantially uniform cross section along the length of the rod, and it is particularly preferred that the rod of aerosol-generating substrate has a substantially circular cross section.

[0127] In a preferred embodiment, the aerosol-forming substrate comprises an assembly of one or more sheets of homogenized tobacco material. Preferably, the one or more sheets of homogenized tobacco material are textured. As used herein, the term "textured sheet" refers to a sheet that is crimped, embossed, debossed, perforated, or otherwise deformed. Textured sheets of homogenized tobacco material used in the present invention may include a plurality of spaced apart indentations, protrusions, perforations, or combinations thereof. According to a particularly preferred embodiment of the present invention, the rod of aerosol-forming substrate comprises an assembly of crimped sheets of homogenized tobacco material surrounded by a wrapper.

[0128] As used herein, the term "crimped sheet" is intended to be synonymous with the term "creased sheet" and refers to a sheet with a plurality of substantially parallel ridges or corrugations. Preferably, the crimped sheet of homogenized tobacco material has a plurality of ridges or corrugations that are substantially parallel to the cylindrical axis of the rod of the present invention. This advantageously facilitates assembly of the crimped sheet of homogenized tobacco material to form a rod. However, it will be understood that the crimped sheet of homogenized tobacco material used in the present invention may alternatively, or additionally, have a plurality of substantially parallel ridges or corrugations that are arranged at an acute or obtuse angle relative 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 uniformly textured across substantially its entire surface. For example, the crimped sheet of homogenized tobacco material used to manufacture the rod for use in the aerosol-generating article of the present invention may include a plurality of substantially parallel ridges or corrugations that are substantially uniformly spaced across the width of the sheet.

[0129] The sheets or webs 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, even more preferably at least about 70 weight percent on a dry weight basis, and most preferably at least about 90 weight percent on a dry weight basis.

[0130] A sheet or web of homogenized tobacco material for use in an aerosol-forming substrate may include one or more intrinsic binders (i.e., tobacco intrinsic binders), one or more extrinsic binders (i.e., tobacco extrinsic binders), or combinations thereof, to assist in agglomerating the particulate tobacco. Alternatively, or in addition, a sheet of homogenized tobacco material for use in an aerosol-forming substrate may include other additives, including, but not limited to, tobacco and non-tobacco fibers, aerosol formers, humectants, plasticizers, flavorants, fillers, aqueous and non-aqueous solvents, and combinations thereof.

[0131] Suitable extrinsic binders for inclusion in sheets or webs of homogenized tobacco material for use in aerosol-forming substrates are well known in the art and include, but are not limited to, gums (e.g., guar gum, xanthan gum, gum arabic, locust bean gum, etc.), cellulosic binders (e.g., hydroxypropyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, methyl cellulose, ethyl cellulose, etc.), polysaccharides (e.g., starch, organic acids (e.g., alginic acid), conjugate base salts of organic acids (e.g., sodium alginate), agar, pectin, etc.), and combinations thereof.

[0132] Suitable non-tobacco fibers for inclusion in sheets or webs of homogenized tobacco material for use in aerosol-forming substrates are well known in the art and include, but are not limited to, cellulose fibers, softwood fibers, hardwood fibers, jute fibers, and combinations thereof. Prior to inclusion in sheets of homogenized tobacco material for use in aerosol-forming substrates, the non-tobacco fibers may be processed by any suitable process known in the art, including, but not limited to, mechanical pulping, refining, chemical pulping, bleaching, sulfate pulping, and combinations thereof.

[0133] The sheet or web of homogenized tobacco material may include an 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 during use and that is substantially resistant to thermal decomposition at the operating temperatures of the aerosol-generating article.

[0134] 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 mono-, di-, or polycarboxylic acids (such as dimethyl dodecanedioate, dimethyl tetradecanedioate, etc.).

[0135] Preferred aerosol formers are polyhydric alcohols such as propylene glycol, triethylene glycol, 1,3-butanediol, and most preferably glycerin, or mixtures thereof.

[0136] The sheet or web of homogenized tobacco material may include a single aerosol former. Alternatively, the sheet or web of homogenized tobacco material may include a combination of two or more aerosol formers.

[0137] The homogenized sheet or web of tobacco material has an aerosol former content of greater than about 10 percent on a dry weight basis. Preferably, the homogenized sheet or web of tobacco material has an aerosol former content of greater than about 12 percent on a dry weight basis. More preferably, the homogenized sheet or web of tobacco material has an aerosol former content of greater than about 14 percent on a dry weight basis. Even more preferably, the homogenized sheet or web of tobacco material has an aerosol former content of greater than about 16 percent on a dry weight basis.

[0138] The sheet of homogenized tobacco material may have an aerosol former content of from about 10 percent to about 30 percent on a dry weight basis. Preferably, the sheet or web of homogenized tobacco material has an aerosol former content of less than 25 percent on a dry weight basis.

[0139] In one preferred embodiment, the sheet of homogenized tobacco material has an aerosol former content of approximately 20 percent on a dry weight basis.

[0140] The homogenized tobacco sheets or webs used in the aerosol-generating articles of the present invention may be made by methods known in the art (e.g., the method disclosed in International Patent Application No. WO-A-2012 / 164009(A2)). In one preferred embodiment, the sheets of homogenized tobacco material used in the aerosol-generating articles are formed by a casting process from a slurry comprising particulate tobacco, guar gum, cellulose fibers, and glycerin.

[0141] Alternative arrangements of homogenized tobacco material within a rod for use in an aerosol-generating article are well known to those skilled in the art and may include multiple stacked sheets of homogenized tobacco material, multiple elongated tubular elements formed by winding strips of homogenized tobacco material around a longitudinal axis, and the like.

[0142] As a further alternative, the rod of aerosol-forming substrate may comprise a non-tobacco-derived nicotine-containing material, such as a sheet of absorbent non-tobacco material loaded with nicotine (e.g., 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 aerosol-forming substrate may comprise a non-tobacco plant material, such as a flavorful non-tobacco plant material.

[0143] The aerosol-forming substrate is surrounded by a wrapper. The wrapper may be made of a porous or non-porous sheet material. The wrapper may be made of any suitable material or combination of materials. Preferably, the wrapper is a paper wrapper.

[0144] The mouthpiece segment comprises a plug of filtration material capable of removing particulate components, gaseous components, or a combination. Suitable filtration materials are known in the art and include, but are not limited to, fibrous filtration materials (e.g., cellulose acetate tow, viscose fibers, polyhydroxyalkanoic acid (PHA) fibers, polylactic acid (PLA) fibers, paper, etc.), adsorbents (e.g., activated alumina, zeolites, molecular sieves, silica gel, etc.), and combinations thereof. In addition, the plug of filtration material may further comprise one or more aerosol modifiers. Suitable aerosol modifiers are known in the art and include, but are not limited to, flavorings such as menthol. In some embodiments, the mouthpiece may further comprise a recess in the mouth end downstream of the plug of filtration material. As an example, the mouthpiece can comprise a hollow tube longitudinally aligned with and positioned immediately downstream of the plug of filtration material, the hollow tube forming a cavity in the mouth end that is open to the outside environment at the downstream end of the mouthpiece and aerosol-generating article.

[0145] The length of the mouthpiece 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 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 is between about 4 millimeters and about 25 millimeters, and more preferably between about 6 millimeters and about 20 millimeters. The length of the mouthpiece may be about 7 millimeters. The length of the mouthpiece may be about 12 millimeters.

[0146] Preferably, the length of the hollow tubular segment is at least about 10 millimeters. More preferably, the length of the hollow tubular segment is at least about 15 millimeters. Additionally or alternatively, the length of the hollow tubular segment is preferably less than about 30 millimeters. More preferably, the length of the hollow tubular segment is less than about 25 millimeters. Even more preferably, the length of the hollow tubular segment is less than about 20 millimeters. In some preferred embodiments, the length of the hollow tubular segment is between about 10 millimeters and about 30 millimeters, more preferably between about 12 millimeters and about 25 millimeters, and even more preferably between about 15 millimeters and about 20 millimeters. By way of 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.

[0147] The hollow tubular segment has a peripheral wall thickness of less than about 1.5 millimeters. Preferably, the hollow tubular segment has a peripheral wall thickness of less than about 1250 micrometers, more preferably less than about 1000 micrometers, and even more preferably less than about 900 micrometers. In a particularly preferred embodiment, the hollow tubular segment has a peripheral wall thickness of less than about 800 micrometers.

[0148] Additionally or alternatively, the hollow tubular segment has a peripheral wall thickness of at least about 100 micrometers. Preferably, the hollow tubular segment has a peripheral wall thickness of at least about 200 micrometers.

[0149] Preferably, the total length of an aerosol-generating article according to the present invention is at least about 40 millimeters. Additionally or alternatively, the total length of an aerosol-generating article according to the present invention is preferably less than about 70 millimeters, more preferably less than about 60 millimeters, and even more preferably less than about 50 millimeters. In preferred embodiments, the total length of an aerosol-generating article is between about 40 millimeters and about 70 millimeters. In an exemplary embodiment, the total length of an aerosol-generating article is about 45 millimeters.

[0150] The support elements (or support segments) can have a length of about 5 millimeters to about 15 millimeters. In a preferred embodiment, the support elements have a length of about 8 millimeters.

[0151] The heater may comprise an elongated heating element configured to pass through the rod of the aerosol-forming substrate when the aerosol-generating article is received within the aerosol-generating device.

[0152] The heater may be any suitable type of heater. The heater may initially heat the aerosol-generating article. Alternatively, the heater may heat the aerosol-generating article externally. Such an external heater may surround the aerosol-generating article when inserted or received within the aerosol-generating device.

[0153] 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 in the cavity. The heater may be located within the cavity. The heater may extend into the cavity. The heater may be an elongated heater. The elongated heater may be blade-shaped. The elongated heater may be pin-shaped. The elongated heater may be cone-shaped. In some embodiments, the aerosol-generating device comprises an elongated heater arranged to be inserted into the aerosol-generating article when the aerosol-generating article is received in the cavity.

[0154] The heater may comprise at least one heating element. The at least one heating element may be of any suitable type. In some embodiments, the device comprises only one heating element. In some embodiments, the device comprises multiple heating elements.

[0155] The heater may include at least one resistive heating element. Preferably, the heater includes multiple resistive heating elements. Preferably, the resistive heating elements are electrically connected in a parallel configuration. Advantageously, providing multiple resistive heating elements electrically connected in a parallel configuration may facilitate delivery of desired power to the heater while reducing or minimizing the voltage required to provide the desired power. Advantageously, reducing or minimizing the voltage required to operate the heater may facilitate reducing or minimizing the physical size of the power supply.

[0156] Suitable materials for forming the at least one resistive heating element include, but are not limited to, semiconductors such as doped ceramics, "conductive" ceramics (e.g., molybdenum disilicide), carbon, graphite, metals, metal alloys, and composites made of ceramic and metallic materials. Such composites may include doped or undoped ceramics. An example of a suitable doped ceramic is doped silicon carbide. Examples of suitable metals include titanium, zirconium, tantalum, and platinum group metals. Examples of suitable metal alloys include stainless steel, nickel-, cobalt-, chromium-, aluminum-, titanium-, zirconium-, hafnium-, niobium-, molybdenum-, tantalum-, tungsten-, tin-, gallium-, manganese-, and iron-containing alloys, as well as nickel-, iron-, cobalt-, and stainless steel-based superalloys, Timetal®, and iron-manganese-aluminum-based alloys.

[0157] In some embodiments, the at least one resistive heating element comprises one or more stamped sections of an electrically resistive material (such as stainless steel). Alternatively, the at least one resistive heating element may comprise a heating wire or filament (e.g., Ni-Cr (nickel-chromium), platinum, tungsten, or alloy wire).

[0158] In some embodiments, the at least one heating element comprises an electrically insulating substrate and the at least one resistive heating element is provided on the electrically insulating substrate.

[0159] The electrically insulating substrate may comprise any suitable material. For example, the electrically insulating substrate may comprise one or more of paper, glass, ceramic, anodized metal, coated metal, and polyimide. The ceramic may comprise mica, alumina (Al2O3), or zirconia (ZrO2). The electrically insulating substrate preferably has a thermal conductivity of about 40 watts per meter Kelvin or less, preferably about 20 watts per meter Kelvin or less, and ideally about 2 watts per meter Kelvin or less.

[0160] The heater may comprise a heating element comprising a rigid, electrically insulating substrate having one or more conductive tracks or wires arranged on its surface. Depending on the size and shape of the electrically insulating substrate, the heater may be able to be inserted directly into the aerosol-forming substrate. If the electrically insulating substrate is not sufficiently rigid, the heating element may comprise additional reinforcing means. An electric current may be passed through one or more conductive tracks to heat the heating element and the aerosol-forming substrate.

[0161] 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, high-frequency oscillating current refers to an oscillating current having a frequency between 500 kHz and 30 MHz. The heater may advantageously include a DC / AC inverter for converting DC current provided by a DC power source into alternating current. The inductor coil may be configured to generate a high-frequency oscillating electromagnetic field upon receiving the high-frequency oscillating current from the power source. The inductor coil may be configured to generate a high-frequency oscillating electromagnetic field within the device cavity. In some embodiments, the inductor coil may substantially surround the device cavity. The inductor coil may extend at least partially along the length of the device cavity.

[0162] 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 comprising a material capable of converting electromagnetic energy into heat. When the susceptor element is positioned within an alternating electromagnetic field, the susceptor is heated. Heating of the susceptor element may be the result of at least one of hysteresis losses and eddy currents induced within the susceptor, depending on the electrical and magnetic properties of the susceptor material.

[0163] The susceptor element may be positioned such that, when an aerosol-generating article is received within the cavity of the aerosol generating device, the oscillating electromagnetic field generated by the inductor coil induces a current in the susceptor element, heating the susceptor element. In these embodiments, the aerosol generating device is preferably capable of generating a fluctuating electromagnetic field having a magnetic field strength (H-field strength) of 1 to 5 kiloamperes per meter (kA / m), preferably 2 to 3 kA / m, e.g., about 2.5 kA / m. Electrically operated aerosol generating devices are preferably capable of generating a fluctuating electromagnetic field having a frequency of 1 to 30 MHz, e.g., 1 to 10 MHz, e.g., 5 to 7 MHz.

[0164] In some embodiments, the susceptor element is located within the aerosol-generating article. In these embodiments, the susceptor element is preferably located in contact with the aerosol-forming substrate. The susceptor element may be located within the aerosol-forming substrate.

[0165] 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 include multiple susceptor elements.

[0166] In some embodiments, the susceptor element is arranged to heat the outer surface of the aerosol-forming substrate, hi some embodiments, the susceptor element is arranged to be inserted into the aerosol-forming substrate when the aerosol-forming substrate is received within the cavity.

[0167] 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. Suitable materials for the elongated susceptor element include graphite, molybdenum, silicon carbide, stainless steel, niobium, aluminum, nickel, nickel-containing compounds, titanium, and composites of metallic materials. Some susceptor elements comprise metal or carbon. Advantageously, the susceptor element may comprise or consist of a ferromagnetic material, such as ferromagnetic alloys (e.g., ferritic iron, ferromagnetic steel, or stainless steel), ferromagnetic particles, and ferrite. Suitable susceptor elements may be or include aluminum. The susceptor element preferably comprises more than about 5 percent, preferably more than about 20 percent, more preferably more than about 50 percent, or more than about 90 percent, of ferromagnetic or paramagnetic material. Some elongated susceptor elements may be heated to temperatures greater than about 250 degrees Celsius.

[0168] The susceptor element may comprise a non-metallic core having a metallic layer disposed thereon. For example, the susceptor element may include a ceramic core or metallic tracks formed on the outer surface of the substrate.

[0169] In some embodiments, the aerosol generating system comprises at least one resistive heating element and at least one inductive heating element, hi some embodiments, the aerosol generating system comprises a combination of a resistive heating element and an inductive heating element.

[0170] The aerosol-generating device may include a power source. The power source may be a DC power source. In some embodiments, the power source is a battery. The power source may be a nickel-metal hydride battery, a nickel-cadmium battery, or a lithium-based battery (e.g., 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 rechargeable and may have a capacity that allows for the storage of sufficient energy for one or more user operations, such as one or more aerosol-generating experiences. For example, the power source may have a capacity sufficient to allow continuous heating of the aerosol-forming substrate for approximately six minutes, corresponding to the typical time it takes to smoke a conventional cigarette, or for a multiple of six minutes. In another example, the power source may have a capacity sufficient to allow for a predetermined number of puffs or for discontinuous activation of the heater.

[0171] Specific embodiments will now be described with reference to the figures. [Brief explanation of the drawings]

[0172] [Figure 1] 1 is a schematic cross-sectional view of a comparative aerosol generating device and a comparative aerosol generating system. [Figure 2] 1 is a schematic cross-sectional view of one embodiment of an aerosol generation system. [Figure 3] FIG. 1 is a schematic cross-sectional view of another embodiment of an aerosol generation system. [Figure 4] 1 is a schematic cross-sectional view of a further embodiment of an aerosol generation system. DETAILED DESCRIPTION OF THE INVENTION

[0173] FIG. 1 illustrates an aerosol generation system 100 including a comparative aerosol generating device 10 and an aerosol-generating article 1. The aerosol generating device 10 includes a housing 4 extending between a mouth 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-generating article 1. An extractor 8 is located within the device cavity defined by the peripheral wall 6 and is configured to receive and extract the aerosol-generating article 1 from the device cavity. The extractor 8 includes a body having an open mouth end and a closed end. The closed end of the body of the extractor 8 is defined by an end wall. The device cavity is further defined by a closed distal end and an open mouth end. The mouth end of the device cavity is located at the mouth end of the aerosol generating device 10. The aerosol-generating article 1 is configured to be received through the mouth end of the device cavity and is configured to abut either the closed end of the device cavity or the closed end of the extractor 8. The closed end of the extractor 8 is configured to substantially abut or be adjacent to the closed end of the device cavity.

[0174] An air flow path 32 is defined around the exterior surface of the extractor 8 and between the peripheral wall 6 of the aerosol-generating device housing 4 and the exterior surface of the extractor 8. Air can enter the extractor 8 through an opening (not shown) present at the closed end of the body of the extractor 8. This allows air to flow downstream through the rod of the aerosol-forming substrate 12 and further through the remainder of the aerosol-generating article 1 when a draw is made by a user at the mouth end of the article 1.

[0175] The aerosol-generating device 10 further comprises a heater (not shown) and a power supply (not shown) for supplying power to the heater. A controller (not shown) is also provided for controlling such a power supply to the heater. The heater is configured to heat the aerosol-generating article 1 during use when the aerosol-generating article 1 is received within the device 10.

[0176] The aerosol-generating article 1 comprises an aerosol-forming substrate rod 12, a hollow support segment 14, a hollow tubular segment 16, and a mouthpiece segment 18. These four elements are longitudinally aligned end-to-end and surrounded by a wrapper 22 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 generating device 1 that includes a heater for heating the aerosol-forming substrate rod 12.

[0177] The aerosol-forming substrate rod 12 has a length of approximately 12 millimeters and a diameter of approximately 7 millimeters. The rod 12 is cylindrical in shape and has a substantially circular cross-section. The rod 12 comprises a collection of sheets of homogenized tobacco material. The hollow cellulose acetate tube (hollow support segment) 14 has a length of approximately 8 millimeters and a thickness of approximately 1 millimeter.

[0178] The mouthpiece segment 18 comprises a plug of 8 denier cellulose acetate tow per filament and has a length of approximately 7 millimeters.

[0179] The hollow tubular segment 16 is provided as a cylindrical tube having a length of approximately 18 millimeters, with a tube wall thickness of approximately 100 micrometers.

[0180] The aerosol-generating article 1 comprises a ventilation zone 26 provided at least about 5 millimeters from the upstream end of the mouthpiece segment 18. The ventilation zone 26 is at least about 12 millimeters from the downstream end of the aerosol-generating article 1. The ventilation zone 26 is at least about 21 millimeters from the downstream end of the rod 12. The ventilation zone 26 comprises a series or row of perforations extending through the wrapper 22.

[0181] As shown in FIG. 1, the ventilation zone 26 of the aerosol-generating article 1 is exposed during use of the system 100.

[0182] 2 illustrates one embodiment of an aerosol generation system 200, comprising an aerosol generation device 20 and an aerosol-generating article 1. The aerosol generation device 20 comprises similar features to those described in connection with the aerosol generation device 10.

[0183] The aerosol-generating device 20 further comprises a vent chamber 28 configured to surround the vent zone 26 of the aerosol-generating article 1 when received within the aerosol-generating device 20. The device cavity has an overall length of 30 mm, and the vent chamber 28 has a length of 6 mm. The vent chamber 28 has a triangular longitudinal cross-sectional shape. The vent chamber 28 is also annular, such that the vent chamber 28 extends around the entire inner periphery of the peripheral wall 6. During use, the vent chamber 28 surrounds the outer periphery of the aerosol-generating article 1.

[0184] Vent chamber 28 is in fluid communication with the exterior surface of aerosol-generating article 1 and the exterior of device 10 via the mouth end of device 10. In particular, vent chamber 28 is configured to be in fluid communication with ventilation zone 26 of article 1. Vent chamber 28 is also configured to be in fluid communication with airflow pathway 32. Vent chamber 28 extends from mouth end 2 of device 20 toward the distal end of the device cavity. As shown in FIG. 2 , vent chamber 28 is defined within the thickness of peripheral wall 6.

[0185] 3 illustrates another embodiment of an aerosol-generating system 300, including an aerosol-generating device 30 and an aerosol-generating article 1. The aerosol-generating device 30 includes an extractor 8 that is shorter than the length of the device cavity. During use, when the aerosol-generating article 10 is received within the device 30, a space is defined between the proximal end of the extractor 8 and the mouth end 2 of the device 30. Such space defines a vent chamber 128, specifically the vent zone 26, surrounding the aerosol-generating article 1. The vent chamber 128 is configured to be in fluid communication with the vent zone 26 of the article 1. The vent chamber 28 is also configured to be in fluid communication with the airflow path 32 defined around the extractor 8. The vent chamber 128 has a length of 6 mm.

[0186] The vent chamber 128 has a rectangular longitudinal cross-sectional shape. The vent chamber 128 is also annular, such that the vent chamber 28 extends around the entire inner periphery of the peripheral wall 6. In other words, during use, the vent chamber 28 surrounds the outer periphery of the aerosol-generating article 1. The vent chamber 128 extends away from the mouth end 2 of the device 30.

[0187] In both the embodiments of FIGS. 2 and 3, the vent chamber 28,128 is in direct fluid communication with the exterior of the aerosol generating device 20,30.

[0188] 4 illustrates another embodiment of an aerosol-generating system 400 comprising an aerosol-generating device 40 and an aerosol-generating article 1. The aerosol-generating device 40 comprises an extractor 8.

[0189] The aerosol-generating device 40 includes a vent chamber 228 configured to surround the ventilation zone 26 of the aerosol-generating article 1 when received within the aerosol-generating device 40. The device cavity has an overall length of 30 mm, and the vent chamber 228 has a length of 6 mm. The vent chamber 228 has a rectangular longitudinal cross-sectional shape. The vent chamber 228 is also annular, such that the vent chamber 228 extends around the entire inner periphery of the peripheral wall 6. During use, the vent chamber 228 surrounds the outer periphery of the aerosol-generating article 1.

[0190] The vent chamber 228 is configured to be in fluid communication with the ventilation zone 26 of the article 1 and the exterior of the aerosol-generating device 40. The vent chamber 228 is also configured to be in fluid communication with the air flow path 32 defined around the extractor 8.

[0191] 4, the vent chamber 228 is located away from the mouth end 2 of the aerosol generation device 40. The vent chamber 228 is not in direct fluid communication with the exterior of the aerosol generation device 40. The vent chamber 228 is in fluid communication with the exterior of the aerosol generation device 40 through a plurality of chamber inlets 44. Each chamber inlet 44 extends between the vent chamber 228 and the mouth end 2 of the aerosol generation device 40, thereby ensuring fluid communication between the vent chamber 228 and the mouth end 2 of the aerosol generation device 40.

[0192] Each chamber inlet 44 has a circular cross-section. The diameter of each chamber inlet 44 is substantially less than the depth (i.e., radial depth) of the vent chamber 228. As shown in Figure 4, the depth of the vent chamber 228 is more than five times the diameter of the chamber inlet 44.

[0193] During use of the above-described aerosol-generating systems 200, 300, 400, the ventilation zone 26 of the aerosol-generating article 1 cannot be directly sealed by the consumer when the aerosol-generating article 1 is received within the cavity of the aerosol-generating device 20, 30, 40. This is because the peripheral wall 6 overlaps with the ventilation zone 26.

Claims

1. 1. An aerosol generating system comprising: An aerosol-generating article, comprising: a rod of aerosol-forming substrate; a filter located downstream of the rod of the aerosol-forming substrate, an aerosol-generating article, the aerosol-forming substrate rod and the filter assembled within a wrapper, the aerosol-generating article comprising a ventilation zone located on the wrapper, the ventilation zone comprising a plurality of openings extending through the wrapper; 1. An aerosol generating device having a distal end and an oral end, said aerosol generating device comprising: a housing having a peripheral wall defining a device cavity for removably receiving the aerosol-generating article at the mouth end of the device; a heater for heating the aerosol-forming substrate when the aerosol-generating article is received within the device cavity; The aerosol generating system is configured such that, when the aerosol-generating article is received within the device cavity, the ventilation zone of the aerosol-generating article is located within the device cavity, and a portion of the inner surface of the peripheral wall that is located on the ventilation zone is separated from the aerosol-generating article.

2. 2. The aerosol generating system of claim 1, wherein the space defined by the portion of the inner surface of the peripheral wall defines a vent chamber within the peripheral wall, the vent chamber being configured to be in fluid communication with the exterior of the aerosol generating device and the ventilation zone of the aerosol-generating article.

3. 3. The aerosol generating system of claim 2, wherein the vent chamber is adjacent the mouth end of the aerosol generating device.

4. 3. The aerosol generating system of claim 2, wherein the vent chamber is located longitudinally away from the mouth end of the aerosol generating device.

5. 5. The aerosol generation system of claim 4, wherein the vent chamber is configured to be in fluid communication with the exterior of the aerosol generation device through a chamber inlet defined in the housing.

6. 6. The aerosol generating system of claim 5, wherein the chamber inlet extends between the vent chamber and the mouth end of the aerosol generating device.

7. 7. An aerosol generating system according to claim 1, wherein the thickness of the portion of the peripheral wall defining the vent chamber is different from the thickness of different portions of the peripheral wall.

8. 8. The aerosol generating system of claim 7, wherein the thickness of the portion of the peripheral wall defining the vent chamber is less than the thickness of a different portion of the peripheral wall.

9. 9. The aerosol generating system of claim 8, wherein the thickness of the portion of the peripheral wall defining the vent chamber varies along a longitudinal axis.

10. 10. The aerosol generating system according to claim 1, wherein the vented chamber is annular.

11. 11. The aerosol generating system of claim 1, wherein the aerosol generating device comprises an extractor for extracting the aerosol-generating article received within the aerosol generating device, the extractor being configured to be movable within the device cavity.

12. 12. The aerosol generating system of claim 11, wherein the extractor is configured to expose the vent chamber when the extractor is in an operating position, the operating position being defined by the heater contacting the aerosol-forming substrate of the aerosol-generating article.

13. 13. The aerosol generation system of claim 11 or 12, wherein an airflow path is defined between the peripheral wall of the aerosol generation device housing and the exterior surface of the extractor, and the ventilation chamber is in fluid communication with the airflow path.

14. The filter of the aerosol-generating article is a mouthpiece segment comprising a plug of filtration material located downstream of the rod of the aerosol-forming substrate; a hollow tubular segment located between the mouthpiece segment and the rod of the aerosol-forming substrate, 14. The aerosol generating system of any one of claims 1 to 13, wherein the ventilation zone is located at a position along the hollow tubular segment.

15. 15. The aerosol generation system of claim 14, wherein the ventilation zone is located at a position along the upstream half of the hollow tubular segment.

16. 16. The aerosol generation system of claim 14 or 15, wherein the plurality of openings in the ventilation zone extend through the hollow tubular segment.

17. 17. The aerosol generating system of claim 1, wherein the heater comprises an elongated heating element configured to penetrate the rod of the aerosol-forming substrate when the aerosol-generating article is received within the aerosol generating device.

18. 18. The aerosol generation system of claim 1, wherein the vent chamber is configured to be in fluid communication with the exterior of the aerosol generation device via the mouth end of the aerosol generation device, preferably via a mouth end face defining the mouth end of the aerosol generation device, preferably such that air enters the vent chamber via the mouth end or mouth end face of the aerosol generation device when the aerosol-generating article is received within the device cavity.

19. 19. The aerosol generation system according to any one of claims 1 to 18, wherein the downstream end of the vent chamber is located at the mouth end of the aerosol generation device.

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