Aerosol generating article having a pointing element

Abstract

Aerosol-generating article having a directing element The aerosol-generating article (100) comprises a heat source (102), an aerosol-forming substrate (104) downstream of the heat source (102), and an airflow directing element (106) downstream of the aerosol-forming substrate. The airflow directing element comprises an air permeable segment (128), which defines a cavity (109). The aerosol-generating article (100) further comprises at least one air inlet (132) for allowing air to be drawn into the aerosol-generating article (100). The aerosol-generating article (100) includes a first airflow path and a second airflow path. The first airflow path extends from the at least one air inlet (132) through the aerosol-forming substrate (104) and into the distal end of the cavity (129). A second airflow path extends from the at least one air inlet (132), through the air permeable segment (128), and into the cavity (129) at a point downstream of the distal end of the cavity (129).

Description

Technical Field

[0001] The present invention relates to an aerosol generating article comprising an airflow directing element. In particular, the present invention relates to an aerosol generating article comprising an airflow directing element and including two airflow paths.

Background Art

[0002] Many smoking articles in which tobacco is heated rather than burned have been proposed in the art. In one well-known type of heated smoking article, an aerosol is generated by the transfer of heat from a combustible heat source to an aerosol-forming substrate downstream of the combustible heat source. During smoking, volatile compounds are released from the aerosol-forming substrate by heat transfer from the combustible heat source and entrained in the air drawn through the smoking article. The released compounds condense as they cool to form an aerosol.

[0003] Air can be drawn into such well-known heated smoking articles through one or more airflow channels provided through the combustible heat source, and the heat transfer from the combustible heat source to the aerosol-forming substrate occurs by convection and conduction. Alternatively, air can be drawn into a well-known heated smoking article through at least one air inlet disposed along the length of the smoking article. The air can pass through the at least one air inlet and travel directly towards the aerosol-forming substrate. In this example, the heat transfer from the heat source to the aerosol-forming substrate can occur mainly by conduction.

[0004] Other well-known smoking articles comprise components downstream of the aerosol-forming substrate. For example, some well-known smoking articles, such as aerosol-generating articles, may comprise an air-directing element downstream of the aerosol-forming substrate. Additionally, such aerosol-generating articles may include at least one air inlet arranged to allow air to move directly to the air-directing element. The air-directing element may be configured such that air can move from at least one air inlet, through a first portion of the air-directing element, to the aerosol-forming substrate, and then through a second portion of the air-directing element. As a result, such an air-directing element may comprise an air-impermeable barrier to prevent air from moving directly from the first portion to the second portion without first passing through the aerosol-forming substrate. However, providing an air-directing element to direct the airflow in the manner described above can be technically challenging or difficult to design.

[0005] There may be a desire to provide an aerosol-generating article that is simpler to manufacture but still provides an acceptable delivery of volatile components from the aerosol-forming substrate. SUMMARY OF THE INVENTION

[0006] According to a first aspect of the present invention, there is provided an aerosol-generating article comprising a heat source and an aerosol-forming substrate downstream of the heat source.

[0007] The aerosol-generating article may further comprise an air-directing element. The air-directing element may be provided downstream of the aerosol-forming substrate. The air-directing element may comprise an air-permeable segment defining a cavity. The aerosol-generating article may further comprise at least one air inlet to allow air to be drawn into the aerosol-generating article. The provision of at least one air inlet may prevent the need for air to move along an airflow channel provided through the combustible heat source. This may advantageously substantially prevent or inhibit the activation of the combustion of the combustible heat source during smoking by the user. This may substantially prevent or inhibit a rapid increase in the temperature of the aerosol-forming substrate during smoking by the user.

[0008] The aerosol-generating article may include a first airflow path that extends from at least one air inlet through the aerosol-forming substrate and into the distal end of the cavity. Advantageously, this enables air passing through the first airflow path to be entrained with aerosol from the aerosol-forming substrate before exiting the aerosol-generating article.

[0009] The aerosol-generating article may include a second airflow path that extends from at least one air inlet through the air-permeable segment and into the cavity at a location downstream of the distal end of the cavity. Providing the second airflow path may mean that a proportion of the air entering the aerosol-generating article through at least one air inlet can move along the first airflow path and that a proportion of the air entering the aerosol-generating article through at least one air inlet can move along the second airflow path.

[0010] Providing the first and second airflow paths obviates the need to include an air-impermeable barrier in the airflow-directing element. Advantageously, this may simplify manufacture of the airflow-directing element. Furthermore, the inventors of the present invention have found that the characteristics of the aerosol delivered to the user can be controlled by controlling the proportion of air passing through each of the first and second airflow paths.

[0011] According to a first aspect of the present invention, there is provided an aerosol generating article preferably comprising a heat source, an aerosol forming substrate downstream of the heat source, and an airflow directing element downstream of the aerosol forming substrate. The airflow directing element comprises an air permeable segment that defines a cavity. The aerosol generating article further comprises at least one air inlet to enable air to be drawn into the aerosol generating article. The aerosol generating article includes a first airflow path and a second airflow path. The first airflow path extends from the at least one air inlet through the aerosol forming substrate into the distal end of the cavity. The second airflow path extends from the at least one air inlet through the air permeable segment into the cavity at a point downstream of the distal end of the cavity.

[0012] The provision of an aerosol generating article according to the present invention can overcome many of the drawbacks associated with the prior art.

[0013] The provision of at least one air inlet can advantageously substantially prevent or inhibit the activation of the combustion of a combustible heat source during smoking by the user. This can substantially prevent or inhibit a rapid increase in the temperature of the aerosol forming substrate during smoking by the user. By preventing or inhibiting the activation of the combustion of the combustible heat source and preventing or inhibiting an excessive temperature increase in the aerosol forming substrate, combustion or thermal decomposition of the aerosol forming substrate under a heavy smoking condition can advantageously be avoided. In addition, the influence of the user's smoking condition on the composition of the mainstream aerosol can advantageously be minimized or reduced.

[0014] Unlike prior art smoking articles, the aerosol-generating articles of the present invention do not include an airflow-directing element having an air-impermeable barrier that prevents air from moving directly from a first portion to a second portion without first passing through an aerosol-forming substrate. Instead, air entering at least one air inlet may follow a second airflow path that extends into the cavity at a point downstream of the distal end of the cavity through an air-permeable segment from the at least one air inlet. This advantageously may simplify the manufacture of the aerosol-generating article. As discussed below, the inventors of the present invention have achieved this by carefully controlling parameters such as the cross-sectional area of the cavity and the position of the at least one air inlet while maintaining an acceptable delivery of volatile components from the aerosol-forming substrate.

[0015] Furthermore, the inventors of the present invention have found that the proportion of air following the first and second airflow paths can be controlled to optimize the delivery of nicotine and aerosol-forming material. As shown in more detail below, this can be achieved by controlling at least one of the diameter of the cavity and the position of the at least one air inlet.

[0016] In use, heat from the heat source is transferred to the aerosol-forming substrate by conduction. Heating of the aerosol-forming substrate may cause the release of volatile components such as nicotine and aerosol-forming material. The aerosol-forming material may include glycerin. When air is drawn into the aerosol-generating article through the at least one air inlet, the air follows either the first airflow path or the second airflow path.

[0017] Air following the first airflow path passes through the aerosol-forming substrate and entrains volatile compounds released from the aerosol-forming substrate to form an aerosol. The aerosol then moves into the cavity through the upstream end of the cavity and exits the aerosol-generating article through the cavity.

[0018] When at least one air inlet is located downstream of the distal end of the airflow directing element, air following the second airflow path can move directly from the air permeable segment into the cavity without passing through the aerosol forming substrate. When at least one air inlet is located upstream of the distal end of the airflow directing element, air following the second airflow path can pass through the aerosol forming substrate before moving into the air permeable segment. In either case, air following the second airflow path moves from the air permeable segment into the cavity at a point downstream of the distal end of the cavity. This air then moves along the cavity towards the downstream end of the cavity and exits the aerosol generating article.

[0019] In addition to simplifying manufacture, the inventors of the present invention have surprisingly found that the airflow through the aerosol generating article can be effectively controlled by varying the diameter of the cavity and the position of at least one air inlet. This is significantly different from prior art aerosol generating articles where the airflow is controlled by the use of air impermeable members (such as tubes).

[0020] By controlling the airflow through the aerosol generating article in this way, the delivery of volatile compounds from the aerosol forming substrate can be achieved. Examples of volatile components include nicotine and aerosol formers. For example, by controlling the diameter of the cavity and the position of at least one air inlet, the delivery of nicotine and aerosol formers can be optimized.

[0021] As used herein in connection with the present invention, the term "air permeable segment" refers to a segment that is not blocked, plugged, or sealed so as to completely prevent air from passing through the air permeable segment. Thus, each portion of the air permeable segment has a finite draw resistance. The manufacture of such an air permeable segment without plugs or seals advantageously reduces manufacturing complexity. Additionally, the manufacture of such an air permeable segment without plugs or seals advantageously reduces or eliminates the need to perform the cumbersome procedure of selecting and testing materials for use in forming seals in order to determine suitability for use in aerosol-generating articles. In certain preferred embodiments, the air permeable segment is open so as to allow air to pass from the upstream end to the downstream end of the air permeable segment.

[0022] The air permeable segment may comprise any suitable material, provided that the material is sufficiently permeable to allow passage of air along the air flow path. The air permeable segment may comprise a fibrous material. The air permeable segment may comprise a porous material. The air permeable segment may comprise at least one of substantially uniformly distributed cellulose acetate tow, polylactic acid, polyhydroxyalkanoate, viscose, polypropylene, or combinations thereof. The density of the cellulose acetate tow provided in the air permeable segment may be used to control the draw resistance of portions of the air permeable segment. The air permeable segment may comprise a hollow acetate tube. When the air permeable segment comprises a hollow acetate tube, the inner surface of the tube defines a cavity. The inner surface of the tube is also air permeable so that air can move from the air permeable segment into the cavity.

[0023] The air-permeable segment may include a material having a density of at least about 0.05 milligrams per cubic millimeter. For example, the air-permeable segment may include a material having a density of at least about 0.1 milligrams per cubic millimeter, or at least about 0.15 milligrams per cubic millimeter. The air-permeable segment preferably includes a material having a density of at least about 0.18 milligrams per cubic millimeter.

[0024] The air-permeable segment may include a fibrous material. For example, the air-permeable segment may include cellulose acetate fibers. The air-permeable segment may include an additive. For example, the air-permeable segment may include a plasticizer such as triacetin.

[0025] The air flow directing element comprises an air-permeable segment that defines a cavity. The air flow directing element may comprise additional components. For example, the air flow directing element may comprise at least one element that surrounds or encloses the air-permeable segment. The additional components may be air-permeable. The additional components may be air-impermeable. The additional components may have any thickness.

[0026] The total cross-sectional area of the air flow directing element, including the air-permeable segment and any additional components, may be the same as, or substantially the same as, the total cross-sectional area of the aerosol-generating article. The total cross-sectional area of the air flow directing element, including the air-permeable segment and any additional components, is substantially the same as the total cross-sectional area of the aerosol-generating article, and the difference may be accounted for by at least one wrapper surrounding the air flow directing element. In this example, the total cross-sectional area of the aerosol-generating article consists of the total cross-sectional area of the air flow directing element, including the air-permeable segment and any additional components, and the cross-sectional area of at least one wrapper.

[0027] As used herein in connection with the present invention, the term "air flow path" is used to describe a path along which air can be drawn through the aerosol-generating article.

[0028] As used herein in connection with the present invention, the terms "upstream" and "forward," and "downstream" and "rearward," are used to describe the relative position of a component or a part of a component of an aerosol-generating article in relation to the direction in which air flows through the aerosol-generating article during use of the aerosol-generating article. An aerosol-generating article according to the present invention comprises a proximal end through which aerosol exits the article during use. The proximal end of the aerosol-generating article may also be referred to as the mouth-side end or the downstream end. The mouth-side end is downstream of the distal end. The heat source is located at or near the distal end. The distal end of the aerosol-generating article may also be referred to as the upstream end. A component or part of a component of the aerosol-generating article may be described as being upstream or downstream of one another based on these relative positions between the proximal end and the distal end of the aerosol-generating article. The forward of a component or part of a component of the aerosol-generating article is the part at the end closest to the upstream end of the aerosol-generating article. The rearward of a component or part of a component of the aerosol-generating article is the part at the end closest to the downstream end of the aerosol-generating article.

[0029] The airflow-directing element and the aerosol-forming substrate may define a first airflow path.

[0030] Advantageously, this may ensure that air following the first airflow path entrains volatile compounds from the aerosol-forming substrate.

[0031] At least one air inlet may be located downstream of the distal end of the airflow-directing element. In this case, air entering the aerosol-generating article through the at least one air inlet may move directly into the aerosol-directing element.

[0032] When at least one air inlet is located downstream of the distal end of the airflow-directing element, air entering the aerosol-generating article through the at least one air inlet may move directly into the air-permeable segment.

[0033] The first airflow path may extend from at least one air inlet through the air-permeable segment, through the aerosol-forming substrate, and into the distal end of the cavity.

[0034] The second airflow path may extend directly from at least one air inlet through the air-permeable segment and into the cavity at a point downstream of the distal end of the cavity.

[0035] When at least one air inlet is located downstream of the distal end of the airflow-directing element, the air following the second airflow path does not pass through the aerosol-forming substrate. Thus, the air following the second airflow path may not directly entrain any volatile compounds from the aerosol-forming substrate. The air following the second airflow path may dilute the aerosol when moving into the cavity at a point downstream of the distal end of the cavity.

[0036] At least one air inlet may be located at any point downstream of the distal end of the airflow-directing element. At least one air inlet may be located between the distal end and the proximal end of the airflow-directing element. At least one air inlet may be located 5 millimeters or less downstream of the distal end of the aerosol-directing element.

[0037] For example, at least one air inlet may be located 3 millimeters or less downstream of the distal end of the airflow-directing element.

[0038] This may help ensure that a certain proportion of the air moving into at least one air inlet passes through the aerosol-forming substrate following the second airflow path. This may advantageously lead to a greater amount of volatile compounds being entrained in the air as the air passes through the aerosol-generating article.

[0039] At least one air inlet may be located upstream of the distal end of the airflow-directing element. In this case, the air entering the aerosol-generating article through at least one air inlet may move directly into the aerosol-forming substrate and may move through either the air-permeable segment or the distal end of the cavity before that.

[0040] The provision of at least one air inlet located upstream of the distal end of the airflow directing element can ensure that air passes through the warmer portion of the aerosol-forming substrate. Advantageously, this can allow a greater amount of volatile compounds to be entrained in the air passing through the aerosol-forming substrate.

[0041] The first airflow path may extend from at least one air inlet, through the aerosol-forming substrate, and into the distal end of the cavity.

[0042] The second airflow path may extend from at least one air inlet, through the aerosol-forming substrate, through the air-permeable segment, and into the cavity at a point downstream of the distal end of the cavity.

[0043] When at least one air inlet is located upstream of the distal end of the airflow directing element, both the first airflow path and the second airflow path pass through the aerosol-forming substrate. Thus, air following both the first airflow path and the second airflow path can directly entrain volatile compounds from the aerosol-forming substrate. Advantageously, this can increase the concentration of volatile compounds in the aerosol.

[0044] At least one air inlet may be located at any point upstream of the distal end of the airflow directing element. At least one air inlet may be located between the distal end and the proximal end of the aerosol-forming substrate. At least one air inlet may be located 5 millimeters or less upstream of the distal end of the aerosol directing element.

[0045] For example, at least one air inlet may be located 3 millimeters or less upstream of the distal end of the airflow directing element.

[0046] At least one upstream air inlet may comprise air inlets of any number or configuration. At least one air inlet may comprise a single air inlet. For example, at least one air inlet may comprise a slit. The slit may be disposed around the aerosol generator or along the longitudinal axis of the aerosol generator.

[0047] At least one air inlet may comprise a plurality of air inlets. For example, at least one air inlet may comprise a plurality of air inlets arranged in a circumferential row, a longitudinal row, or any other pattern. If at least one air inlet comprises at least one row of air inlets, each row may comprise a plurality of air inlets. At least one row of air inlets may surround the aerosol article. Each individual air inlet may form a hole in the outer wrapper (and any other wrapper) such that air can pass through the air inlet and towards either the aerosol-forming substrate or the airflow-directing element. If at least one row of air inlets comprises a plurality of rows of air inlets, adjacent rows of air inlets may be separated by from 0.5 millimeters to 6 millimeters. Adjacent rows of air inlets may be separated by 1 millimeter.

[0048] If at least one air inlet comprises a plurality of air inlets, at least one air inlet may comprise a plurality of slits. For example, at least one air inlet may comprise at least a first slit and a second slit. Adjacent slits may be separated by from 0.5 millimeters to 6 millimeters. Adjacent slits may be separated by 1 millimeter.

[0049] At least one air inlet may comprise a plurality of air inlet zones. A first air inlet zone may be located downstream of the distal end of the airflow-directing element. A second air inlet zone may be located upstream of the distal end of the airflow-directing element.

[0050] The downstream end of the aerosol-forming substrate may abut against the upstream end of the airflow-directing element.

[0051] This can force the air moving from the air-permeable segment towards the aerosol-forming substrate to move into the aerosol-forming substrate and then directly into the cavity, rather than moving into the gap. Advantageously, this can lead to a greater amount of volatile compounds being entrained in at least one air inlet located downstream of the distal end of the airflow-directing element in a first airflow path.

[0052] The air-permeable segment may have any shape. For example, the air-permeable segment may have the shape of a prism. The air-permeable segment may be a cylindrical air-permeable segment.

[0053] The cavity may have any shape. For example, the cavity may have the shape of a prism. The cavity may be a cylindrical cavity.

[0054] The air-permeable segment may be a cylindrical air-permeable segment, and the cavity may be a cylindrical cavity.

[0055] The cavity may be located at the center within the air-permeable segment. The longitudinal axis of the cavity may be parallel to the longitudinal axis of the air-permeable segment.

[0056] The cavity may have any cross-sectional shape. For example, the cavity may have a circular cross-section, or a square cross-section, or a clover-leaf cross-section.

[0057] The cavity may have the same outer cross-sectional shape as the air-permeable segment.

[0058] The longitudinal cross-sectional area of the cavity may be at least 14 percent of the total longitudinal cross-sectional area of the aerosol-generating article. In this case, the cavity occupies at least 14 percent of the total cross-sectional area of the aerosol-generating article.

[0059] For example, the cross-sectional area in the major axis direction of the cavity may be at least 18 percent, at least 20 percent, at least 25 percent, at least 27 percent, at least 30 percent, or at least 35 percent of the total cross-sectional area in the major axis direction of the aerosol-generating article.

[0060] Providing a cavity having a cross-sectional area of at least 14 percent of the total cross-sectional area in the major axis direction of the aerosol-generating article is advantageously capable of maximizing the delivery of volatile components such as nicotine and aerosol-forming substances. Without wishing to be bound by theory, providing a cavity having a smaller cross-sectional area relative to the total cross-sectional area in the major axis direction of the aerosol-generating article may lead to a portion of the volatile compounds being removed from the aerosol as the aerosol moves along the cavity towards the downstream end of the airflow-directing element. Additionally, when at least one air inlet is located upstream of the distal end of the airflow-directing element, air following a second airflow path entraining volatile compounds from the aerosol-forming substrate has to travel a longer distance through the air-permeable segment before moving into the cavity at a point downstream of the distal end of the cavity. This can lead to a higher proportion of the volatile compounds being removed from the aerosol.

[0061] As a result, increasing the cross-sectional area of the cavity relative to the total cross-sectional area in the major axis direction of the aerosol-generating article can increase the delivery of volatile compounds by reducing the proportion of volatile compounds removed by the air-permeable segment.

[0062] The cross-sectional area in the major axis direction of the cavity may be 40 percent or less of the total cross-sectional area in the major axis direction of the aerosol-generating article. In this case, the cavity occupies 40 percent or less of the total cross-sectional area of the aerosol-generating article.

[0063] For example, the cross-sectional area in the major axis direction of the cavity may be 35 percent or less, or 30 percent or less of the total cross-sectional area in the major axis direction of the aerosol-generating article.

[0064] Providing a cavity having a cross-sectional area of 40 percent or less of the total cross-sectional area in the longitudinal axis direction of the aerosol-generating article can advantageously maximize the delivery of volatile components such as nicotine and aerosol-forming substances. Without wishing to be bound by theory, providing a cavity having a larger cross-sectional area relative to the total cross-sectional area in the longitudinal axis direction of the aerosol-generating article can lead to a larger proportion of air following a second air flow path. When at least one air inlet is located downstream of the distal end of the air flow directing element, this may mean that a larger proportion of the air does not pass through the aerosol-forming substrate at all, meaning that the air following the second air flow path will not entrain volatile compounds from the aerosol-forming substrate. Further, when at least one air inlet is located upstream of the distal end of the air flow directing element, this may mean that when air enters the aerosol-forming substrate through at least one air inlet before moving into the distal end of the cavity, the air following the first air flow path passes through less of the aerosol-forming substrate. This can lead to less volatile compounds being entrained by the air following the second air flow path.

[0065] As a result, reducing the cross-sectional area of the cavity relative to the total cross-sectional area in the longitudinal axis direction of the aerosol-generating article can increase the delivery of volatile compounds by forcing more air through the aerosol-forming substrate.

[0066] The cross-sectional area in the longitudinal axis direction of the cavity may be from 14 percent to 40 percent of the total cross-sectional area in the longitudinal axis direction of the aerosol-generating article.

[0067] For example, the cross-sectional area in the longitudinal axis direction of the cavity may be from 18 percent to 35 percent, 30 percent to 40 percent, 30 percent to 35 percent, 35 percent to 40 percent, 20 percent to 35 percent, or 25 percent to 30 percent of the total cross-sectional area in the longitudinal axis direction of the aerosol-generating article.

[0068] In some preferred embodiments, the cross-sectional area in the longitudinal axis direction of the cavity is about 27 percent of the total cross-sectional area in the longitudinal axis direction of the aerosol-generating article.

[0069] As shown above, providing a cavity having a major axis cross-sectional area that is large relative to the total cross-sectional area in the major axis direction of the aerosol-generating article can result in a reduction in the air flowing through the aerosol-forming substrate, but can also result in a reduction in the volatile compounds removed from the aerosol by the air-permeable segment. Conversely, providing a cavity having a major axis cross-sectional area that is small relative to the total cross-sectional area in the major axis direction of the aerosol-generating article can result in an increase in the volatile compounds removed from the aerosol by the air-permeable segment, but can also result in an increase in the air flowing through the aerosol-forming substrate.

[0070] With these competing factors in mind, the inventors of the present invention have found that a cavity having a major axis cross-sectional area of 14 percent to 40 percent of the total cross-sectional area in the major axis direction of the aerosol-generating article represents an optimal balance between these effects. Providing a cavity having a major axis cross-sectional area of 14 percent to 40 percent of the total cross-sectional area in the major axis direction of the aerosol-generating article can provide an optimal delivery of volatile components such as nicotine and aerosol-forming substances.

[0071] The air flow directing element may have a diameter of from about 5 millimeters to about 9 millimeters. For example, the air flow directing element may have a diameter of from about 5.4 millimeters to about 8.1 millimeters. For example, the aerosol-generating article may have a diameter of about 7.8 millimeters.

[0072] The air flow directing element may have a major axis cross-sectional area of at least 19 square millimeters. For example, the air flow directing element may have a major axis cross-sectional area of at least 25 square millimeters, or at least 30 square millimeters.

[0073] The air flow directing element may have a major axis cross-sectional area of 50 square millimeters or less. For example, the air flow directing element may have a major axis cross-sectional area of 40 square millimeters or less, or 35 square millimeters or less.

[0074] The air flow directing element may have a cross-sectional area in the major axis direction of 19 square millimeters to 50 square millimeters, 25 square millimeters to 40 square millimeters, and 30 square millimeters to 35 square millimeters.

[0075] The air flow directing element may have a cross-sectional area in the major axis direction of 40 square millimeters.

[0076] The cavity may have a diameter of at least 1 millimeter. For example, the cavity may have a diameter of at least 2 millimeters, or at least 3 millimeters.

[0077] The cavity may have a diameter of 6 millimeters or less. For example, the cavity may have a diameter of 5 millimeters or less, or 4 millimeters or less.

[0078] The cavity may have a diameter of 4 millimeters.

[0079] The cavity may have a cross-sectional area in the major axis direction of at least 3 square millimeters. For example, the cavity may have a cross-sectional area in the major axis direction of at least 5 square millimeters, or at least 10 square millimeters.

[0080] The cavity may have a cross-sectional area in the major axis direction of 30 square millimeters or less. For example, the cavity may have a cross-sectional area in the major axis direction of 20 square millimeters or less, or 15 square millimeters or less.

[0081] The cavity may have a cross-sectional area in the major axis direction of 3 square millimeters to 30 square millimeters, 5 square millimeters to 20 square millimeters, and 10 square millimeters to 15 square millimeters.

[0082] The cavity may have a cross-sectional area in the major axis direction of 12 square millimeters.

[0083] The airflow directing element may have any length. For example, the airflow directing element may have a length of 10 millimeters to 40 millimeters, 15 millimeters to 35 millimeters, or 20 millimeters to 30 millimeters. The airflow directing element may have a length of 25 millimeters.

[0084] The heat source may be any heat source. The heat source may be a single-use heat source. The heat source may be a multi-use heat source. The heat source may be a combustible heat source, a chemical heat source, an electrical heat source, or any other heat source. The heat source may be a combustible heat source.

[0085] The heat source may be a blind heat source. The heat source may be a blind combustible heat source.

[0086] As used herein in connection with the present invention, the term "blind" describes a heat source that does not include an airflow channel extending from the front end face to the rear end face of the combustible heat source. The term "blind" as used herein in connection with the present invention is also used to describe a combustible heat source that includes one or more channels extending from the front end face of the combustible heat source to the rear end face of the combustible heat source, in which case a substantially air-impermeable barrier of combustibility between the rear end face of the combustible heat source and the aerosol-forming substrate barrier prevents air from being drawn through one or more airflow channels along the length of the combustible heat source.

[0087] In use, the air drawn along the first or second airflow path of the aerosol-generating article according to the invention, which comprises a blind combustible heat source, does not pass through any airflow channels along the blind combustible heat source. The absence of an airflow channel through the blind combustible heat source advantageously substantially prevents or inhibits the activation of the combustion of the blind combustible heat source during smoking by the user. This substantially prevents or inhibits a rapid increase in the temperature of the aerosol-forming substrate during smoking by the user. By preventing or inhibiting the activation of the combustion of the blind combustible heat source and thus preventing or inhibiting an excessive temperature rise in the aerosol-forming substrate, combustion or thermal decomposition of the aerosol-forming substrate under intense smoking conditions can advantageously be avoided. In addition, the effect of the user's smoking regime on the composition of the mainstream aerosol may advantageously be minimized or reduced.

[0088] Also, the inclusion of a blind combustible heat source advantageously substantially prevents or inhibits combustion products, decomposition products, other materials formed during ignition and combustion of the blind combustible heat source from entering the air drawn through the aerosol-generating article according to the invention during use of the aerosol-generating article. This is particularly beneficial when the blind combustible heat source contains one or more additives to assist in the ignition or combustion of the blind combustible heat source.

[0089] In the aerosol-generating article according to the invention comprising a blind combustible heat source, heat transfer from the blind combustible heat source to the aerosol-forming substrate occurs mainly by conduction. Heating of the aerosol-forming substrate by forced convection is minimized or reduced. This can advantageously help to minimize or reduce the effect of the user's smoking regime on the composition of the mainstream aerosol of the article according to the invention.

[0090] The heat source may be a solid heat source.

[0091] As used herein in connection with the present invention, the term "aerosol-forming substrate" is used to describe a substrate having the ability to release upon heating a volatile compound capable of forming an aerosol. An aerosol generated from the aerosol-forming substrate of an aerosol-generating article according to the present invention may be visible or invisible and may include vapors (e.g., particulate matter in the gaseous state of a substance that is normally liquid or solid at room temperature), as well as droplets of gas and condensed vapor.

[0092] The aerosol-forming substrate may be a solid aerosol-forming substrate. Alternatively, the aerosol-forming substrate may comprise both a solid component and a liquid component. The aerosol-forming substrate may include a tobacco-containing material containing a volatile tobacco flavor compound released from the substrate upon heating. Alternatively, the aerosol-forming substrate may include a non-tobacco material. The aerosol-forming substrate may further include one or more aerosol-forming agents. Examples of suitable aerosol-forming agents include, but are not limited to, glycerin and propylene glycol.

[0093] The aerosol-forming substrate may be a rod containing a tobacco-containing material.

[0094] When the aerosol-forming substrate is a solid aerosol-forming substrate, the solid aerosol-forming substrate may contain one or more of herb leaves, tobacco leaves, fragments of tobacco stems, reconstituted tobacco, homogenized tobacco, extruded tobacco, expanded tobacco, for example, one or more of powders, granules, pellets, fragments, spaghetti-like twists, shreds, or sheets. The solid aerosol-forming substrate may be in a loose form or may be provided in a suitable container or cartridge. For example, the aerosol-forming material of the solid aerosol-forming substrate may be enclosed within paper or other wrapper and may have the form of a plug. When the aerosol-forming substrate is in the form of a plug, the entire plug including any wrapper is considered to be the aerosol-forming substrate.

[0095] The solid aerosol-forming substrate may contain additional tobacco or non-tobacco volatile flavor compounds that are released upon heating of the solid aerosol-forming substrate. The solid aerosol-forming substrate may also contain capsules, for example, containing additional tobacco or non-tobacco volatile flavor compounds, and such capsules may dissolve during heating of the solid aerosol-forming substrate.

[0096] The solid aerosol-forming substrate may be provided on or embedded within a thermally stable carrier. The carrier may take the form of a powder, granule, pellet, fragment, spaghetti-like twist, flake, or sheet. The solid aerosol-forming substrate may be deposited on the surface of the carrier, for example, in the form of a sheet, foam, gel, or slurry. The solid aerosol-forming substrate may be deposited over the entire surface of the carrier or, alternatively, deposited in a pattern to provide non-uniform flavor delivery during use.

[0097] The aerosol-forming substrate may be in the form of a plug or segment comprising a material that has the ability to emit volatile compounds in response to heating and is surrounded by paper or other wrapper. When the aerosol-forming substrate is in the form of such a plug or segment, the entire plug or segment including any wrapper is considered to be the aerosol-forming substrate.

[0098] The aerosol-forming substrate preferably has a length of from about 5 millimeters to about 20 millimeters. In certain embodiments, the aerosol-forming substrate may have a length of from about 6 millimeters to about 15 millimeters, or from about 7 millimeters to about 12 millimeters.

[0099] The aerosol-forming substrate may comprise a plug of tobacco-derived material wrapped within a plug wrap. In a preferred embodiment, the aerosol-forming substrate comprises a plug of homogenized tobacco-derived material wrapped within a plug wrap.

[0100] The aerosol-generating article may comprise a thermally conductive element around and in direct contact with the rear portion of the heat source and the adjacent front portion of the aerosol-forming substrate. The thermally conductive element is preferably combustion resistant.

[0101] The thermally conductive element may be around and in direct contact with both the rear portion of the combustible heat source and the front portion of the aerosol-forming substrate. The thermally conductive element can provide a thermal link between these two components of the aerosol-generating article.

[0102] Suitable thermally conductive elements for use in the aerosol-generating article according to the present invention include, but are not limited to, metal foil wrappers (such as aluminum foil wrappers, steel wrappers, iron foil wrappers, copper foil wrappers, etc.), and metal alloy foil wrappers.

[0103] When the heat source is a combustible heat source, the rear portion of the combustible heat source surrounded by the thermally conductive element may have a length of about 2 millimeters to about 8 millimeters, more preferably a length of about 3 millimeters to about 5 millimeters.

[0104] The front portion of the combustible heat source may not be surrounded by the thermally conductive element. The front portion of the combustible heat source not surrounded by the thermally conductive element may have a length of about 4 millimeters to about 15 millimeters, more preferably a length of about 4 millimeters to about 8 millimeters.

[0105] The aerosol-forming substrate may extend downstream beyond the thermally conductive element by at least about 3 millimeters.

[0106] The front portion of the aerosol-forming substrate surrounded by the heat-conductive element may have a length of about 2 millimeters to about 10 millimeters, more preferably a length of about 3 millimeters to about 8 millimeters, and most preferably a length of about 4 millimeters to about 6 millimeters. The rear portion of the aerosol-forming substrate not surrounded by the heat-conductive element may have a length of about 3 millimeters to about 10 millimeters. In other words, it is preferred that the aerosol-forming substrate extends downstream beyond the heat-conductive element by about 3 millimeters to about 10 millimeters. More preferably, the aerosol-forming substrate extends downstream beyond the heat-conductive element by at least about 4 millimeters.

[0107] The aerosol-forming substrate may extend downstream less than 3 millimeters beyond the heat-conductive element.

[0108] The entire length of the aerosol-forming substrate may be surrounded by the heat-conductive element.

[0109] The aerosol-generating article according to the present invention may comprise an expansion chamber downstream of the aerosol-forming substrate and the air flow-directing element. Inclusion of the expansion chamber may advantageously allow for further cooling of the aerosol generated by heat transfer from the combustible heat source to the aerosol-forming substrate. Advantageously, the expansion chamber may allow for adjustment of the overall length of the aerosol-generating article according to the present invention to a desired value by appropriate selection of the length of the expansion chamber. The expansion chamber may be an elongated hollow tube.

[0110] The aerosol-generating article may comprise a filter segment configured to further cool the aerosol. The filter segment may include PLA.

[0111] The aerosol-generating article may comprise a mouthpiece downstream of the aerosol-forming substrate and the airflow-directing element and, if present, downstream of the expansion chamber. The mouthpiece may have a low filtration efficiency or a very low filtration efficiency. The mouthpiece may be a single-segment or single-component mouthpiece. The mouthpiece may be a multi-segment mouthpiece or a multi-component mouthpiece.

[0112] The mouthpiece may comprise a filter made of cellulose acetate, paper or other suitable well-known filtration materials. The mouthpiece may comprise one or more segments containing absorbents, adsorbents, flavorants, other aerosol modifiers and additives, or combinations thereof.

[0113] The aerosol-generating article may have a diameter of from about 5 millimeters to about 9 millimeters. For example, the aerosol-generating article may have a diameter of from about 5.4 millimeters to about 8.1 millimeters. For example, the aerosol-generating article may have a diameter of about 7.8 millimeters.

[0114] The aerosol-generating article may have any length. For example, the aerosol-generating article may have an overall length of from approximately 65 millimeters to approximately 100 millimeters. The aerosol-generating article may have any desired outer diameter. For example, the aerosol-generating article may have an outer diameter of from approximately 5 millimeters to approximately 12 millimeters.

[0115] Of course, specific combinations of the various features described and defined in any aspect of the present invention can be implemented, supplied, or used independently.

[0116] The following provides a non-exhaustive list of non-limiting examples. Any one or more of the features of these examples may be combined with any one or more of the features of another example, embodiment, or aspect described herein.

[0117] A: An aerosol-generating article comprising a heat source, an aerosol-forming substrate downstream of the heat source, an airflow-directing element downstream of the aerosol-forming substrate, the airflow-directing element comprising a gas-permeable segment that defines a cavity, and at least one air inlet for enabling air to be drawn into the aerosol-generating article, wherein the aerosol-generating article comprises a first airflow path and a second airflow path, the first airflow path extending from the at least one air inlet, through the aerosol-forming substrate, into the distal end of the cavity, and the second airflow path extending from the at least one air inlet, through the gas-permeable segment, into the cavity at a point downstream of the distal end of the cavity.

[0118] B: The aerosol-generating article according to embodiment A, wherein the at least one air inlet is located downstream of the distal end of the airflow-directing element.

[0119] C: The aerosol-generating article according to embodiment B, wherein the first airflow path extends from the at least one air inlet, through the gas-permeable segment, through the aerosol-forming substrate, into the distal end of the cavity.

[0120] D: The aerosol-generating article according to embodiment B or C, wherein the second airflow path extends directly from the at least one air inlet, through the gas-permeable segment, into the cavity at a point downstream of the distal end of the cavity.

[0121] E: The aerosol-generating article according to any one of embodiments B to D, wherein the at least one air inlet is located 5 millimeters or less downstream of the distal end of the airflow-directing element.

[0122] F: The aerosol-generating article according to embodiment A, wherein the at least one air inlet is located upstream of the distal end of the airflow-directing element.

[0123] G: The aerosol-generating article according to embodiment F, wherein the first airflow path extends from the at least one air inlet, through the aerosol-forming substrate, into the distal end of the cavity.

[0124] H: An aerosol-generating article according to Example F or Example G, wherein a second air flow path extends from at least one air inlet through an aerosol-forming substrate, through an air-permeable segment, and into the cavity at a point downstream of the distal end of the cavity.

[0125] I: An aerosol-generating article according to any one of Examples F to H, wherein at least one air inlet is located 5 millimeters or less upstream of the distal end of the air flow directing element.

[0126] J: An aerosol-generating article according to any one of Examples A to I, wherein the downstream end of the aerosol-forming substrate abuts the upstream end of the air flow directing element.

[0127] K: An aerosol-generating article according to any one of Examples A to J, wherein the air-permeable segment is a cylindrical air-permeable segment and the cavity is a cylindrical cavity.

[0128] L: An aerosol-generating article according to any one of Examples A to K, wherein the cavity has a circular cross-section, or a square cross-section, or a clover-leaf-shaped cross-section.

[0129] M: An aerosol-generating article according to any one of Examples A to L, wherein the cross-sectional area of the cavity in the longitudinal axis direction is at least 14 percent of the total cross-sectional area of the aerosol-generating article in the longitudinal axis direction.

[0130] N: An aerosol-generating article according to any one of Examples A to M, wherein the cross-sectional area of the cavity in the longitudinal axis direction is 40 percent or less of the total cross-sectional area of the aerosol-generating article in the longitudinal axis direction.

[0131] O: An aerosol-generating article according to any one of Examples A to N, wherein the cross-sectional area of the cavity in the longitudinal axis direction is 14 percent to 40 percent of the total cross-sectional area of the aerosol-generating article in the longitudinal axis direction.

[0132] P: An aerosol generating article according to any one of Examples A to O, wherein an air flow directing element and an aerosol-forming substrate define a first air flow path.

[0133] Q: An aerosol generating article according to any one of Examples A to P, wherein the heat source is a blind heat source.

[0134] R: An aerosol generating article according to any one of Examples A to Q, wherein the heat source is a solid heat source.

[0135] S: An aerosol generating article according to any one of Examples A to R, wherein the heat source is a combustible heat source.

[0136] Although only by way of illustration, the present invention will be further described with reference to the following accompanying drawings.

Brief Description of the Drawings

[0137]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Modes for Carrying Out the Invention

[0138] The aerosol generating article 100 according to the first embodiment of the present invention shown in FIG. 1 comprises a blind combustible carbonaceous heat source 102, an aerosol forming substrate 104, an air flow directing element 106, and a mouthpiece 110, which are provided in abutting coaxial alignment. The combustible carbonaceous heat source 102, the aerosol forming substrate 104, the air flow directing element 106, and the mouthpiece 110 are wrapped by an outer wrapper 112 of low air permeability cigarette paper.

[0139] The aerosol forming substrate 104 is located immediately downstream of the combustible carbonaceous heat source 102 and comprises a cylindrical plug 114 of tobacco material containing glycerin as an aerosol former and surrounded by a plug wrap (not shown).

[0140] A non-combustible and substantially air-impermeable barrier is provided between the downstream end of the combustible heat source 102 and the upstream end of the aerosol forming substrate 104. As shown in FIG. 1, the non-combustible and substantially air-impermeable barrier consists of a non-combustible and substantially air-impermeable barrier coating 118 provided over the entire rear face of the combustible carbonaceous heat source 102.

[0141] A heat conductive element 120 consisting of a tubular layer of aluminum foil surrounds and is in direct contact with the rear portion 122 of the combustible carbonaceous heat source 102 and the abutting front portion 124 of the aerosol forming substrate 104. As shown in FIG. 1, the rear portion of the aerosol forming substrate 104 is not surrounded by the heat conductive element 120.

[0142] The airflow directing element 106 is located downstream of the aerosol-forming substrate 104 and includes an air-permeable segment 128 that defines a cavity 129. The air-permeable segment 128 includes substantially uniformly distributed cellulose acetate tow. The cavity 129 is provided along the central longitudinal axis of the air-permeable segment 128. The cross-sectional area in the longitudinal direction of the cavity 129 is 20 percent of the total cross-sectional area of the aerosol-generating article 100. Both the distal end and the proximal end of the cavity 129 are open so that air can move into the distal end of the cavity 129, move along the length of the cavity 129, and exit the cavity 129 through the proximal end of the cavity.

[0143] As shown in FIG. 1, the air-permeable segment 128 is surrounded by an inner wrapper 130.

[0144] Also as shown in FIG. 1, at least one air inlet 132 is provided in the outer wrapper 112 and the inner wrapper 130. The at least one air inlet 132 includes a plurality of air inlets arranged circumferentially around the aerosol-generating article. In the aerosol-generating article 100 shown in FIG. 1, the at least one air inlet 132 is located 3 millimeters downstream of the distal end of the airflow directing element 106.

[0145] The mouthpiece 110 of the aerosol-generating article 100 is located downstream of the airflow directing element 106 and includes a cylindrical plug 136 of cellulose acetate tow with a very low filtration efficiency surrounded by a filter plug wrap 138. The mouthpiece 110 may be surrounded by tipping paper (not shown).

[0146] In use, when the combustible carbonaceous heat source 102 is ignited, the aerosol-forming substrate 104 is heated by conduction through the abutting rear portion 122 of the combustible carbonaceous heat source 102 and the heat-conductive element 120. Heating of the aerosol-forming substrate 104 releases volatile compounds including glycerin and nicotine from the plug 114 of tobacco material.

[0147] The non-combustible and substantially air-impermeable barrier coating 118 provided on the rear surface of the combustible carbonaceous heat source 102 separates the combustible carbonaceous heat source 102 from the airflow path through the aerosol generating article 100 such that air drawn through the aerosol generating article 100 along the first and second portions of the airflow path does not come into direct contact with the combustible carbonaceous heat source 102 during use.

[0148] Air is drawn into the aerosol generating article 100 through at least one air inlet 132. This air first enters the air permeable segment 128 of the airflow directing element 106.

[0149] The first portion of this air moves from the air permeable segment 128, through the distal end of the airflow directing element 106, and into the aerosol forming substrate 104 along a first airflow path. As the air passes through the aerosol forming substrate 104, the air along the first airflow path entrains volatile compounds from the aerosol forming substrate 104 to form an aerosol. The air then moves into the distal end of the cavity 129. The aerosol cools and condenses as it moves along the cavity 129.

[0150] The second portion of the air entering the aerosol generating article 100 through the at least one air inlet 132 follows a second airflow path. This air moves directly from the air permeable portion 128 of the airflow directing element 106 and into the cavity 129 at a point downstream of the distal end of the cavity 129. Since this air does not directly entrain volatile compounds from the aerosol forming substrate 104, it can act to dilute the aerosol entrained by the air along the first airflow path.

[0151] Air following both the first and second airflow paths passes through the proximal end of the cavity 129 and exits the aerosol generating article 100 through the mouthpiece 110.

[0152] The first and second airflow paths are identified by the dashed lines and arrows in FIG. 1.

[0153] Figure 2 shows an alternative aerosol generating article 100 according to the present invention. The aerosol generating article 100 shown in Figure 2 has substantially the same structure as the aerosol generating article 100 shown in Figure 1, and like reference numerals are used to identify common features. However, the aerosol generating article 100 shown in Figure 2 further comprises an expansion chamber 108 located downstream of the airflow directing element 106 and upstream of the mouthpiece 110. The expansion chamber 108 comprises an open-ended hollow tube 134, made of, for example, cardboard, which has substantially the same diameter as the aerosol forming substrate 104. To maintain the overall length of the aerosol generating article 100, both the airflow directing element 106 and the mouthpiece 110 are shorter than the corresponding features of the aerosol generating article shown in Figure 1.

[0154] Figure 3 shows an alternative aerosol generating article 100 according to the present invention. The aerosol generating article 100 shown in Figure 3 has substantially the same structure as the aerosol generating article 100 shown in Figure 1, and like reference numerals are used to identify common features. However, at least one air inlet 132 is located 3 millimeters upstream of the distal end of the airflow directing element 106.

[0155] In the aerosol generating article shown in Figure 3, air is drawn into the aerosol generating article 100 through at least one air inlet 132. This air first enters the aerosol forming substrate 104, where it entrains volatile compounds from the aerosol forming substrate 104.

[0156] Next, a first portion of the air moves along a first airflow path into the distal end of the cavity 129. As the aerosol moves along the cavity 129, it cools and condenses.

[0157] Next, a second portion of the air moves along a second airflow path through the distal end of the air permeable segment 128. The air then moves into the cavity 129 at a point downstream of the distal end of the cavity 129, following the second airflow path.

[0158] Air following both the first and second airflow paths passes through the proximal end of cavity 129, through mouthpiece 110, and exits aerosol-generating article 100.

[0159] The first and second airflow paths are identified by the dashed lines and arrows in FIG. 3.

[0160] FIGS. 4 and 5 show the results of tests to determine the optimal cross-sectional area of the cavity.

[0161] Four aerosol-generating articles according to the present invention were manufactured. Each aerosol-generating article had an airflow-directing element with a cavity having a different cross-sectional area. Each aerosol-generating article was held at 22° C. and 40 percent relative humidity for 48 hours and then kept in a sealed aluminum bag prior to evaluation.

[0162] The downstream end of each aerosol-generating article was connected to a smoking machine, a combustible heat source was ignited, and each of the aerosol-generating articles was subjected to the same smoking cycle. After the smoking cycle, the aerosol-forming substrate and the air-permeable portion of the airflow-directing element were removed, and the mass of glycerin (acting as an aerosol former) in each was measured.

[0163] FIG. 4 is a graph showing the mass of glycerin obtained from the aerosol-forming substrate as a function of the cross-sectional area of the cavity. The mass of glycerin per aerosol-forming substrate is shown in milligrams on vertical axis 210, and the cross-sectional area of the cavity is shown in square millimeters on horizontal axis 215. As shown in this graph, the mass of glycerin obtained from the aerosol-forming substrate after use of the aerosol-generating article increases as the diameter of the cavity increases.

[0164] As shown above, the provision of a cavity having a larger cross-sectional area can lead to a larger proportion of the air following the second airflow path. If at least one air inlet is located downstream of the distal end of the airflow directing element, this may mean that a larger proportion of the air does not pass through the aerosol-forming substrate at all, meaning that the air following the second airflow path will not entrain glycerin from the aerosol-forming substrate. This can lead to an increase in the mass of glycerin remaining in the aerosol-forming substrate as the cross-sectional area of the cavity increases.

[0165] Figure 5 is a graph showing the mass of glycerin obtained from the air-permeable portion of the airflow directing element according to the cross-sectional area of the cavity. The mass of glycerin per aerosol-forming substrate is shown in milligrams on the vertical axis 220, and the cross-sectional area of the cavity is shown in square millimeters on the horizontal axis 215. As shown in the graph, the mass of glycerin obtained from the air-permeable portion of the airflow directing element after use of the aerosol-generating article decreases as the diameter of the cavity increases.

[0166] As shown above, the provision of a cavity having a smaller cross-sectional area can lead to a larger proportion of the glycerin entrained by the airflow through the cavity being removed from the aerosol and absorbed by the air-permeable portion of the airflow directing element. This can lead to an increase in the mass of glycerin remaining in the air-permeable portion of the airflow directing element as the cross-sectional area of the cavity decreases.

[0167] As a result, the inventors have found that in order to optimize the delivery of volatile components such as nicotine and glycerin, it is necessary to balance these two effects. In other words, the cross-sectional area of the cavity must be selected to maximize the release of volatile components such as nicotine and glycerin from the aerosol-forming substrate and, on the other hand, to minimize the adsorption of nicotine by the air-permeable portion of the airflow directing element.

[0168] Furthermore, as can be seen from FIG. 5, when the cross-sectional area of the cavity reaches about 12 square millimeters, the mass of glycerin observed in the air-permeable portion of the air flow directing element increases significantly. As a result, the inventors have found that one way to optimize the delivery of volatile components such as nicotine and glycerin could be to provide a cavity having a cross-sectional area of about 12 square millimeters. This corresponds to a diameter of about 4 millimeters.

[0169] The specific embodiments and examples described above illustrate the present invention but do not limit the present invention. Other embodiments of the present invention may be made, and it is understood that the specific embodiments and examples described herein are not exhaustive.

[0170] For the purposes of this specification and the claims, all numbers representing amounts, quantities, percentages, etc., unless otherwise indicated, should be understood to be modified in all instances by the term "about." Also, all ranges include the disclosed maximum and minimum points and any intermediate ranges therebetween, whether or not specifically enumerated herein.

Claims

1. An aerosol-generating article, comprising: a heat source; an aerosol-forming substrate downstream of the heat source; an airflow-directing element downstream of the aerosol-forming substrate, the airflow-directing element comprising a permeable segment that defines a cavity; at least one air inlet to enable air to be drawn into the aerosol-generating article. The aerosol-generating article includes a first airflow path and a second airflow path. The first airflow path extends from the at least one air inlet through the aerosol-forming substrate and into the distal end of the cavity. The second airflow path extends from the at least one air inlet through the permeable segment and into the cavity at a point downstream of the distal end of the cavity, and the at least one air inlet is located downstream of the distal end of the airflow-directing element. The aerosol-generating article, wherein a cross-sectional area in the longitudinal axis direction of the cavity is at least 30 percent of the total cross-sectional area in the longitudinal axis direction of the aerosol-generating article.

2. The aerosol-generating article according to claim 1, wherein the permeable segment comprises a material having a density of at least 0.05 milligrams per cubic millimeter.

3. The aerosol-generating article according to claim 1 or claim 2, wherein the at least one air inlet is located 3 millimeters or less downstream of the distal end of the airflow-directing element.

4. The aerosol-generating article according to any one of claims 1 to 3, wherein the first airflow path extends from the at least one air inlet through the permeable segment, through the aerosol-forming substrate, and into the distal end of the cavity.

5. The aerosol generating article according to any one of claims 1 to 4, wherein the second air flow path extends directly into the cavity at a point downstream of the distal end of the cavity through the air permeable segment from the at least one air inlet.

6. The aerosol generating article according to any one of claims 1 to 5, wherein a downstream end of the aerosol forming substrate abuts an upstream end of the air flow directing element.

7. The aerosol generating article according to any one of claims 1 to 6, wherein the air permeable segment is a cylindrical air permeable segment and the cavity is a cylindrical cavity.

8. The aerosol generating article according to any one of claims 1 to 7, wherein the cavity has a circular cross-section, a square cross-section, or a clover leaf-shaped cross-section.

9. The aerosol generating article according to any one of claims 1 to 8, wherein a cross-sectional area of the cavity in the longitudinal axis direction is 40 percent or less of a total cross-sectional area of the aerosol generating article in the longitudinal axis direction.

Images