Aerosol-generating device comprising airflow guiding element extending into heating chamber

Abstract

An aerosol-generating device (100) is provided having a mouth end for receiving an aerosol-generating article. An aerosol-generating device comprises a heating chamber (108) for receiving an aerosol-generating article (1) at a mouth end (102) of the device. The aerosol-generating device comprises a heating element (110) disposed at or around a periphery of the heating chamber for heating an aerosol-generating article received within the heating chamber. The aerosol-generating device comprises an airflow directing element (20) located within the heating chamber and extending longitudinally towards the mouth end of the device. The airflow directing element is configured to be inserted into the aerosol-generating article when the aerosol-generating article is received within the heating chamber. The width or outer diameter of the airflow guiding element varies along its length.

Description

Technical Field

[0001] The present invention relates to an aerosol generating device for heating an aerosol generating article, the aerosol generating article comprising a strip of an aerosol generating substrate adapted to generate an inhalable aerosol when heated. The present disclosure also relates to an aerosol generating system comprising such an aerosol generating device and an aerosol generating article configured to be received by the aerosol generating device. Background Art

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

[0003] Many prior art documents disclose aerosol generating devices for consuming aerosol generating articles. Such devices include, for example, electrically heated aerosol generating devices, in which an aerosol is generated by transferring heat from one or more electric heater elements of the aerosol generating device to an aerosol generating substrate of a heated aerosol generating article. For example, electrically heated aerosol generating devices including internal heater blades have been proposed, and the internal heater blades are suitable for being inserted into the aerosol generating substrate. It is also known to use aerosol generating articles in combination with external heating systems. For example, WO-A-2020 / 115151 describes the provision of external heating elements arranged around the periphery of the aerosol generating article when the aerosol generating article is received in the cavity of the aerosol generating device. As an alternative, WO-A-2015 / 176898 proposes an inductively heatable aerosol generating article, which includes an aerosol generating substrate and a receptor arranged in the aerosol generating substrate.

[0004] In general, it may be difficult to provide efficient heating of an aerosol generating substrate over the entire strip of the entire substrate. The portion of the substrate closest to the heating element will inevitably be heated most efficiently, and the imperfect transfer of heat through the substrate will mean that the portion of the substrate farthest from the heating element may not be heated efficiently. Therefore, the aerosol generation from these portions of the substrate that are not effectively heated is not optimal, and in some cases, portions of the substrate may not reach a sufficiently high temperature to generate an aerosol during use. For example, in the case of using an external heating element to heat the strip of an aerosol generating substrate, as described above, the central portion of the strip of the aerosol generating substrate is unlikely to generate as much aerosol as the outer portion of the strip, and in some cases, may not generate any aerosol. In a word, the aerosol generation from the aerosol generating strip may therefore be inefficient, wherein a portion of the aerosol generating substrate may be wasted.

[0005] In addition, the aerosol-generating substrate generally does not generate an aerosol immediately upon activation of the heating element. This is because there is a warm-up time after activation of the heating element during which the aerosol-generating substrate is heated to the temperature required for aerosol generation. Therefore, there may be a relatively long duration between activation of the heating element and generation of an organoleptically acceptable aerosol for inhalation by the user. Summary of the invention

[0006] Therefore, it is desirable to provide an aerosol generating article having an aerosol generating substrate, which is suitable for providing a more efficient aerosolization of the aerosol generating substrate and reducing the waste of substrate materials such as tobacco. It is also desirable to provide such an aerosol generating article, which can achieve a relatively short preheating time, so that a sensory acceptable aerosol can be delivered to the user shortly after starting to heat the aerosol generating substrate. It is also desirable to provide such an aerosol generating article, which can provide optimized aerosol delivery from the aerosol generating substrate. It is particularly desirable to provide such an aerosol generating article, which has a relatively simple design so that it can be manufactured and incorporated into existing product designs in a cost-effective manner. It is also desirable to provide such a product, which can be easily adapted so that it can be heated in various types of heating devices, including induction heating devices and resistance heating devices.

[0007] An aerosol generating device is provided, having a mouth end for receiving an aerosol generating article. The aerosol generating device may include a heating chamber for receiving an aerosol generating article at the mouth end of the device. The aerosol generating device may include a heating chamber for receiving and heating an aerosol generating article. The aerosol generating device may include an airflow directing element, which is located in the heating chamber and extends longitudinally toward the mouth end of the device. The airflow directing element may include an elongated body. The airflow directing element may be inserted into the aerosol generating article or received in the aerosol generating article when the article is received in the heating chamber. The width or outer diameter of the airflow directing element may vary along its length. A first portion of the airflow directing element may have a width or outer diameter corresponding to the maximum width or outer diameter of the airflow directing element. A second portion of the airflow directing element located upstream of the first portion may have a width or outer diameter less than the maximum width or outer diameter of the airflow directing element.

[0008] An aerosol generating device is also provided, having a mouth end for receiving an aerosol generating article. The aerosol generating device may include a heating chamber for receiving the aerosol generating article at the mouth end of the device. The aerosol generating device may include a heating element, which is arranged at the periphery of the heating chamber or around the periphery of the heating chamber for heating the aerosol generating article received in the heating chamber. The aerosol generating device may include an airflow directing element, which is located in the heating chamber and extends longitudinally toward the mouth end of the device. The airflow directing element may be configured to be inserted into the aerosol generating article when the aerosol generating article is received in the heating chamber. In other words, the airflow directing element may be received in the aerosol generating article when the article is received in the heating chamber.

[0009] According to the present invention, an aerosol generating device is provided, which has a mouth end for receiving an aerosol generating article. The aerosol generating device includes a heating chamber for receiving and heating the aerosol generating article. The aerosol generating device includes an airflow directing element, which is located in the heating chamber and extends longitudinally toward the mouth end of the device. The airflow directing element is inserted into the aerosol generating article or is received in the aerosol generating article when the article is received in the heating chamber. The width or outer diameter of the airflow directing element varies along its length. A first portion of the airflow directing element has a width or outer diameter corresponding to the maximum width or outer diameter of the airflow directing element. A second portion of the airflow directing element located upstream of the first portion has a width or outer diameter that is less than the maximum width or outer diameter of the airflow directing element.

[0010] An aerosol generating system is also provided, comprising an aerosol generating device according to the present disclosure and an aerosol generating article for generating an inhalable aerosol when heated. The aerosol generating article may include an aerosol generating substrate. The aerosol generating substrate may be in the form of a hollow tubular segment, which defines a substrate cavity extending from the upstream end of the aerosol generating substrate to the downstream end of the aerosol generating substrate. When the aerosol generating article is received in the heating chamber of the device, the airflow directing element may extend longitudinally or protrude into the substrate cavity. As a result, the airflow channel may be defined between the outer surface of the airflow directing element and the inner surface of the aerosol generating substrate.

[0011] According to the present invention, an aerosol generating system is also provided, which includes an aerosol generating device according to the present disclosure and an aerosol generating article for generating an inhalable aerosol when heated. The aerosol generating article includes an aerosol generating substrate. The aerosol generating substrate is in the form of a hollow tubular segment, which defines a substrate cavity extending from the upstream end of the aerosol generating substrate to the downstream end of the aerosol generating substrate. When the aerosol generating article is received in the heating chamber of the device, the airflow directing element extends longitudinally into the substrate cavity. The airflow channel is defined between the outer surface of the airflow directing element and the inner surface of the aerosol generating substrate.

[0012] As used herein with reference to the present disclosure, the term "aerosol-generating article" is used to describe an article comprising an aerosol-generating substrate, which is heated to generate an inhalable aerosol for delivery to a user.

[0013] As used herein with reference to the present disclosure, the term "aerosol-generating substrate" is used to describe a substrate comprising an aerosol-generating material, which substrate is capable of releasing volatile compounds that can generate an aerosol upon heating.

[0014] As used herein with reference to the present disclosure, the term "aerosol" is used to describe a dispersion of solid particles or liquid droplets, or a combination of solid particles and liquid droplets, in a gas. An aerosol may be visible or invisible. An aerosol may include vapors of a substance that is normally liquid or solid at room temperature, as well as solid particles or liquid droplets, or a combination of solid particles and liquid droplets.

[0015] Aerosol-generating articles according to the present disclosure have a downstream end through which, in use, an aerosol leaves the aerosol-generating article for delivery to a user. The downstream end of the aerosol-generating article may also be referred to as the proximal end or mouth end of the aerosol-generating article. In use, a user draws directly or indirectly on the downstream end of the aerosol-generating article to inhale an aerosol generated by the aerosol-generating article.

[0016] Aerosol-generating articles according to the present disclosure have an upstream end. The upstream end is opposite to the downstream end. The upstream end of the aerosol-generating article may also be referred to as the distal end of the aerosol-generating article.

[0017] Components or portions of aerosol-generating articles and devices according to the present disclosure may be described as being upstream or downstream of each other based on their relative position between an upstream end of the aerosol-generating article or device and a downstream end of the aerosol-generating article or device. The downstream end of the aerosol-generating device may correspond to the mouth end or distal end of the aerosol-generating device. The upstream end of the aerosol-generating device may correspond to the end of the aerosol-generating device opposite to the downstream end.

[0018] As used herein with reference to the present disclosure, the term "longitudinal" refers to the direction between an upstream end and an opposite downstream end of an aerosol-generating article or device.

[0019] As used herein with reference to the present disclosure, the term "lateral" is used to describe a direction perpendicular to the longitudinal direction.

[0020] As used herein with reference to the present disclosure, the term "cross-section" is used to refer to a cross-section of an aerosol-generating article or a component thereof, unless otherwise stated.

[0021] As used herein with reference to the present disclosure, the term "radial" is used to describe a direction determined by a line extending in a plane perpendicular to the central longitudinal axis of the aerosol-generating article and passing through the point where the central longitudinal axis intersects the perpendicular plane. Thus, as used herein with reference to the present disclosure, the term "radial direction" refers to a direction perpendicular to the central longitudinal axis and is used, for example, when describing an aerosol-generating article having a substantially cylindrical shape.

[0022] As used herein with reference to the present disclosure, the terms "hollow tubular element" and "hollow tubular matrix element" refer to a generally elongated element that defines a lumen, cavity, or airflow passage along its longitudinal axis. In particular, the term "tubular" is used to refer to a tubular element having a substantially cylindrical cross-section and defining at least one airflow conduit that establishes uninterrupted fluid communication between an upstream end of the tubular element and a downstream end of the tubular element. However, it should be understood that alternative geometries of the tubular element (e.g., alternative cross-sectional shapes) may be possible. The hollow tubular element may be a single discrete element of an aerosol-generating article having a defined length and thickness. The term "hollow tubular matrix" or "hollow tubular matrix element" refers to an aerosol-generating substrate in the form of a hollow tube.

[0023] As used herein with reference to the present disclosure, the term "homogenized tobacco material" includes any material formed by agglomeration of tobacco particles.Homogenized tobacco material may be produced by casting, extrusion, papermaking processes or any other suitable process known in the art.

[0024] As used herein with reference to the disclosure, the term "tobacco particles" describes particles of any plant member of the Nicotiana genus. The term "tobacco particles" includes ground or pulverized tobacco leaves, ground or pulverized tobacco leaf stems, tobacco dust, tobacco fines and other particle tobacco byproducts formed during the processing, operation and transportation of tobacco. Preferably, tobacco particles are substantially all derived from tobacco leaves. In contrast, separated nicotine and nicotine salts are compounds derived from tobacco, but are not considered to be tobacco particles for purposes of the disclosure.

[0025] The provision of an elongated airflow directing element extending or protruding into a heating chamber of an aerosol generating device provides a centering means which ensures that an aerosol generating article inserted into the device, particularly those having an open and hollow upstream end and an aerosol generating substrate therein, is substantially aligned with the central longitudinal axis of the heating chamber. This may be particularly important for devices having a heater located at or around the periphery of the heating chamber for external heating of a received aerosol generating article. The airflow directing element may help to center the aerosol generating article and its substrate relative to the heater of the device so that the entire periphery of the aerosol generating substrate is positioned substantially at a consistent distance from the surrounding heater.

[0026] In aerosol generating articles and systems according to the present disclosure, the arrangement of the substrate element of tubular form can advantageously enable the amount of tobacco material in the aerosol generating substrate to be optimized, so that aerosol can be efficiently generated from the aerosol generating substrate when heated. The tubular form also removes the central portion of the homogenized tobacco material, which may not be heated as effectively as the outer portion, particularly in an aerosol generating device comprising an external heating device. In a word, compared with the conventional solid rod of homogenized tobacco material, the amount of tobacco material can therefore be significantly reduced, and tobacco waste can be reduced. For example, it has been found that, compared with the amount of tobacco material of the solid rod of the substrate used for conventional aerosol generating articles, the amount of tobacco material used for the hollow tubular substrate element of aerosol generating articles according to the present disclosure can be reduced by up to 40%, while maintaining similar aerosol delivery to consumers.

[0027] By controlling the parameters of the hollow tubular matrix element, such as the density and wall thickness of the peripheral wall of the hollow tubular matrix element, the amount of tobacco material disposed in the matrix can be easily modified. In this way, the hollow tubular matrix element can be modified so that it matches the heating zone of the associated aerosol generating device. Thus, the proportion of the aerosol generating substrate that can be heated to the required temperature for aerosol generation can be maximized, so that the generation of aerosol from the aerosol generating substrate is optimized.

[0028] The hollow tubular substrate element has a relatively simple structure which can be produced in a simple and cost-effective manner using existing equipment.The hollow tubular substrate element can then be included into an aerosol-generating article together with other components using known assembly methods and equipment.

[0029] When the aerosol generating article including opening the upstream end and the hollow tubular aerosol generating substrate is received in the aerosol generating device including the airflow guiding element extending longitudinally into the heating chamber and extending along the heating chamber, the article can receive the airflow guiding element of the device via the upstream end of the article, so that the airflow guiding element extends longitudinally into the empty substrate cavity defined by the hollow tubular aerosol generating substrate. As a result, an airflow channel or path is defined around the airflow guiding element between the outer surface of the airflow guiding element and the inside of the aerosol generating substrate, so that the air entering the substrate cavity is closer to the inner surface flow of the aerosol generating substrate. The airflow guiding element protrudes into the cavity and effectively provides an airflow path, and the airflow path has a cross-section reduced relative to the cross-section of the cavity, so that the air entering the cavity can be locally accelerated (according to the Bernoulli principle) when flowing through this airflow path. This local airflow acceleration can enhance the extraction of aerosol-forming components from the heated aerosol generating substrate, which is particularly important for the tubular substrate with a hollow core. As a result, such an airflow arrangement can improve aerosol delivery produced by articles having a hollow tubular substrate and reduce the time required for the substrate to generate a sensory acceptable aerosol after it is initially heated, while reducing manufacturing costs and potential waste of substrate material that may not contribute to aerosol generation.

[0030] In addition, providing an upstream portion of the airflow directing element having a diameter smaller than a downstream portion of the airflow directing element (whose diameter corresponds to the maximum diameter of the airflow directing element) ensures that the air flowing around the airflow directing element encounters a reduced cross-sectional area of ​​the airflow channel defined between the outer surface of the airflow directing element and the inner surface of the aerosol generating substrate of the aerosol generating article received in the device cavity of the aerosol generating device due to the increase in the diameter of the airflow directing element (further along the airflow directing element and not at the base (or upstream end or proximal end) of the airflow directing element). This increase in diameter or width may disturb the airflow and push the air closer to the inner surface of the received aerosol generating substrate, thereby promoting local turbulent airflow and local airflow acceleration to form between the airflow directing element (particularly at the location of the increase in diameter or width) and the inner surface of the aerosol generating substrate. This can improve aerosol generation due to enhanced mixing of the air with the aerosol-forming components released from the aerosol generating substrate when heated.

[0031] As described above, aerosol generating articles according to the present disclosure comprise a hollow tubular substrate element. Preferably, the hollow tubular substrate element is formed from homogenised tobacco material. Preferably, the hollow tubular substrate element is formed from one or more layers of homogenised tobacco material (eg cast leaf).

[0032] Preferably, the hollow tubular substrate element is formed from 2 or more overlapping layers of homogenised tobacco material, more preferably from 3 or more overlapping layers of homogenised tobacco material.

[0033] The hollow tubular matrix element is preferably formed from up to 10 overlapping layers of homogenized tobacco material, more preferably from up to 5 overlapping layers of homogenized tobacco material. For example, the hollow tubular matrix element can be formed from about 2 to about 10 overlapping layers of homogenized tobacco material, or about 3 to about 5 overlapping layers of homogenized tobacco material.

[0034] Preferably, the multiple overlapping layers of homogenised tobacco material directly overlie each other such that adjacent layers are in direct contact with each other without intervening layers.

[0035] The multilayer arrangement of the layers may provide a relatively dense structure having sufficient structural rigidity to provide the aerosol-generating substrate in an aerosol-generating article without the need for any additional support, such as a carrier layer or internal support members within the longitudinal substrate cavity.

[0036] Preferably, the layer of homogenised tobacco material is in the form of a sheet.As used herein with reference to the present disclosure, the term "sheet" describes a laminar element having a width and length which is significantly greater than its thickness.

[0037] The hollow tubular matrix element may have a length of at least about 5 mm, or at least about 7 mm, or at least about 10 mm.

[0038] The hollow tubular matrix element may have a length of up to about 30 mm, up to about 25 mm, or up to about 20 mm.

[0039] For example, the hollow tubular matrix element can have a length between about 5 mm and about 30 mm, or between about 7 mm and about 25 mm, or between about 10 mm and about 20 mm.

[0040] Preferably, the hollow tubular matrix element has a length of about 12 mm.

[0041] As discussed above, the length of the hollow tubular substrate element may advantageously match the longitudinal dimension of a heating element in a corresponding aerosol generating device to be used to heat the aerosol generating article. In this way, as much of the aerosol generating substrate as possible may be heated during use in order to optimize the amount of aerosol that can be generated and reduce the amount of tobacco waste.

[0042] Preferably, the ratio of the length of the hollow tubular substrate element to the total length of the aerosol-generating article is at least about 0.1. More preferably, the ratio of the length of the hollow tubular substrate element to the total length of the aerosol-generating article is at least about 0.15. More preferably, the ratio of the length of the hollow tubular substrate element to the total length of the aerosol-generating article is at least about 0.2.

[0043] Preferably, the ratio of the length of the hollow tubular substrate element to the total length of the aerosol-generating article is up to about 0.6. More preferably, the ratio of the length of the hollow tubular substrate element to the total length of the aerosol-generating article is up to about 0.55. More preferably, the ratio of the length of the hollow tubular substrate element to the total length of the aerosol-generating article is up to about 0.5.

[0044] For example, the ratio of the length of the hollow tubular substrate element to the overall length of the aerosol-generating article may be between about 0.1 and about 0.6, more preferably between about 0.15 and about 0.55, more preferably between about 0.2 and about 0.5.

[0045] Preferably, the outer diameter of the hollow tubular substrate element is smaller than the outer diameter of the aerosol-generating article.

[0046] Preferably, the hollow tubular matrix element may have an outer diameter of at least about 5 mm, or at least about 5.5 mm, or at least 6 mm.

[0047] Preferably, the hollow tubular matrix element may have an outer diameter of up to about 9 mm, or up to about 8 mm, or up to about 7.5 mm.

[0048] For example, the hollow tubular matrix element can have an outer diameter between about 5 mm and about 9 mm, or between about 5.5 mm and 8 mm, or between about 6 mm and 7.5 mm.

[0049] Preferably, the outer diameter of the hollow tubular matrix element is substantially constant along the length of the hollow tubular matrix. Alternatively, different portions of the hollow tubular matrix element may have different outer diameters.

[0050] As used herein with reference to the present disclosure, the term "outer diameter" refers to the maximum diameter of an aerosol generating article, or a component thereof, in the transverse direction of the aerosol generating article at a position along the length of the aerosol generating article, or a component thereof. In the case of ranges or values ​​for the outer diameter of an aerosol generating article, or a component thereof, described herein, the outer diameter of the aerosol generating article, or a component thereof, may fall within the same range or have the same value along the entire length of the aerosol generating article, or a component thereof. In other words, in the case of ranges or values ​​for the outer diameter of an aerosol generating article, or a component thereof, described herein, the outer diameter of the aerosol generating article, or a component thereof, may fall within the same range or have the same value at all positions along the length of the aerosol generating article, or a component thereof.

[0051] The outer diameter of the hollow tubular substrate element does not include the width of any other components of the aerosol-generating substrate that are located outside of the hollow tubular substrate element.

[0052] The hollow tubular matrix element has a peripheral wall defining a longitudinal cavity or matrix cavity. The wall thickness of the hollow tubular matrix element can be selected based on the desired amount of tobacco material in the hollow tubular matrix. The wall thickness of the hollow tubular matrix element can also be selected so that the hollow tubular matrix element has a sufficiently high rigidity so that it can be self-supporting. The wall thickness of the hollow tubular matrix can also be selected so that the longitudinal cavity has a cross-sectional area that provides a desired resistance to draw (RTD) for the hollow tubular matrix element.

[0053] The hollow tubular matrix element may have a wall thickness of at least about 4% of the outer diameter of the hollow tubular matrix element, or at least about 5% of the outer diameter of the hollow tubular matrix element, or at least about 6% of the outer diameter of the hollow tubular matrix element.

[0054] The hollow tubular matrix element may have a wall thickness of up to about 40% of the outer diameter of the hollow tubular matrix element, or up to about 30% of the outer diameter of the hollow tubular matrix element, or up to about 20% of the outer diameter of the hollow tubular matrix element.

[0055] For example, the hollow tubular matrix element can have a wall thickness of between about 4% and about 40% of the outer diameter of the hollow tubular matrix element, or between about 5% and about 30% of the outer diameter of the hollow tubular matrix element, or between about 6% and about 20% of the outer diameter of the hollow tubular matrix element.

[0056] Preferably, the hollow tubular matrix element has a wall thickness of about 7% of the outer diameter of the hollow tubular matrix element.

[0057] The hollow tubular matrix element may have a wall thickness of at least about 0.3 mm, or at least about 0.35 mm, or at least about 0.4 mm. The hollow tubular matrix element may have a wall thickness of at least about 0.5 mm. The hollow tubular matrix element may have a wall thickness of at least about 0.6 mm. The hollow tubular matrix element may have a wall thickness of at least about 0.8 mm. The hollow tubular matrix element may have a wall thickness of at least about 1 mm.

[0058] The hollow tubular matrix element may have a wall thickness of up to about 3 mm, or up to about 2 mm, or up to about 1 mm.

[0059] For example, the hollow tubular matrix element can have a wall thickness of between about 0.3 mm and about 3 mm, or between about 0.35 mm and about 2 mm, or between about 0.4 mm and about 1 mm.

[0060] The hollow tubular matrix element may have a wall thickness between about 0.5 mm and about 2 mm. The hollow tubular matrix element may have a wall thickness between about 1 mm and about 2 mm.

[0061] The hollow tubular matrix element may have a wall thickness of about 0.5 mm. The hollow tubular matrix element may have a wall thickness of about 1 mm.

[0062] As described above, the longitudinal lumen provides an unrestricted flow passage through the hollow tubular matrix element. This means that the hollow tubular matrix element provides a negligible level of resistance to suction (RTD). The term "negligible level of RTD" is used to describe an RTD of less than 1 mm HO / 10 mm length of the hollow tubular matrix element, preferably less than 0.4 mm HO / 10 mm length of the hollow tubular matrix element, and more preferably less than 0.1 mm HO / 10 mm length of the hollow tubular matrix element.

[0063] Therefore, the longitudinal cavity should be free of any components that would impede the flow of air in the longitudinal direction. Preferably, the longitudinal cavity is substantially empty. More preferably, the longitudinal cavity is empty.

[0064] The longitudinal cavity may also be referred to as a longitudinal air flow channel.

[0065] The longitudinal cavity extends between the ends of the hollow tubular matrix element and is preferably open at both the upstream and downstream ends. The open upstream end may provide a primary air inlet for drawing air through the aerosol generating article when a consumer draws on the article. Thus, the longitudinal cavity may provide a primary passage for air and aerosol to flow through the article.

[0066] The aerosol-generating substrate may have a length of at least about 10 mm, at least about 12 mm, or at least about 15 mm.

[0067] The aerosol-generating substrate may have a length of up to about 40 mm, up to about 37 mm or up to about 35 mm.

[0068] For example, the aerosol-generating substrate may have a length of between about 10 mm and about 40 mm, or between about 12 mm and about 37 mm, or between about 15 mm and about 35 mm.

[0069] The diameter of the longitudinal lumen corresponds to the inner diameter of the hollow tubular matrix element.

[0070] The longitudinal lumen may have a diameter of at least about 1 mm, or at least about 2 mm, or at least about 3 mm.

[0071] The longitudinal lumen may have a diameter of up to about 8 mm, or up to about 7 mm, or up to about 6.5 mm.

[0072] For example, the longitudinal lumen can have a diameter between about 1 mm and about 8 mm, or between about 2 mm and about 7 mm, or between about 3 mm and about 6.5 mm.

[0073] The longitudinal lumen may have a diameter of approximately 6 mm.

[0074] The diameter of the longitudinal cavity can be selected so that the volume of the cavity is large enough that it provides the desired level of airflow, while also maintaining sufficient wall thickness. This is necessary so that a sufficient amount of tobacco material is provided within the hollow tubular matrix element, and so that the hollow tubular matrix element has a sufficiently high rigidity so that it can be self-supporting.

[0075] Preferably, the longitudinal lumen has a substantially constant cross-sectional shape and size along the length of the hollow tubular matrix. However, one or both of the cross-sectional shape and size of the longitudinal lumen may vary along the length of the hollow tubular matrix element.

[0076] Preferably, the longitudinal cavity has a substantially circular cross-section.Alternatively, the longitudinal cavity may have a substantially oval cross-section.

[0077] The longitudinal lumen may have a constant diameter along the length of the hollow tubular matrix element. However, the diameter of the longitudinal lumen may vary along the length of the hollow tubular matrix element.

[0078] The central longitudinal axis of the hollow tubular matrix element is preferably aligned with the central longitudinal axis of other elements of the aerosol-generating article (e.g., other components of the aerosol-generating substrate and components of the downstream section). For example, the central longitudinal axis of the hollow tubular matrix element is preferably aligned with the central longitudinal axis of both the upstream element and the downstream element. The central longitudinal axis of the hollow tubular matrix element is preferably aligned with the central longitudinal axis of the aerosol-generating article.

[0079] The hollow tubular substrate element may include one or more susceptor elements positioned in contact with the peripheral wall to inductively heat the homogenised tobacco material during use.

[0080] 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 located in an alternating electromagnetic field, the susceptor is heated. The heating of the susceptor element may be the result of at least one of hysteresis losses and eddy currents induced in the susceptor, depending on the electrical and magnetic properties of the susceptor material.

[0081] Preferably, the hollow tubular matrix element comprises one or more susceptor elements on the surface of the peripheral wall. The hollow tubular matrix element may comprise one or more susceptor elements on the inner surface of the peripheral wall within the longitudinal airflow channel. Alternatively or in addition, the hollow tubular matrix element may comprise one or more susceptor elements on the outer surface of the peripheral wall.

[0082] The susceptor element may comprise any suitable material. The susceptor element may be formed of any material that can be inductively heated to a temperature sufficient to release volatile compounds from the aerosol generating substrate. Suitable materials for the elongated susceptor element include graphite, molybdenum, silicon carbide, stainless steel, niobium, aluminum, nickel, nickel-containing compounds, titanium, and metal material composites. Some susceptor elements include metal or carbon. Advantageously, the susceptor element may include or consist of a ferromagnetic material, such as ferritic iron, ferromagnetic alloys (e.g., ferromagnetic steel or stainless steel), ferromagnetic particles, and ferrites. Suitable susceptor elements may be aluminum or include aluminum. The susceptor element preferably comprises greater than about 5%, preferably greater than about 20%, more preferably greater than about 50%, or greater than about 90% ferromagnetic or paramagnetic material. Some elongated susceptor elements may be heated to a temperature exceeding about 250 degrees Celsius.

[0083] Aerosol generating articles according to the present disclosure may also include an upstream section located upstream of the strip of aerosol generating substrate. The upstream section is preferably positioned immediately upstream of the strip of aerosol generating substrate. The upstream section preferably extends between the upstream end of the aerosol generating article and the strip of aerosol generating substrate. The upstream section may include one or more upstream elements located upstream of the strip of aerosol generating substrate. Such one or more upstream elements are described within the present disclosure.

[0084] Aerosol-generating articles of the present disclosure preferably include an upstream element located upstream of and adjacent to the aerosol-generating substrate.The upstream element advantageously prevents direct physical contact with the upstream end of the aerosol-generating substrate.

[0085] Furthermore, the presence of an upstream element helps to prevent any loss of the substrate, which may be advantageous, for example, if the substrate contains particulate plant material.

[0086] Where the aerosol-generating substrate comprises shredded tobacco (such as tobacco cut filler), the upstream section or elements thereof may additionally help prevent loose tobacco particles from being lost from the upstream end of the article. This may be particularly important, for example, when the shredded tobacco has a relatively low density.

[0087] The upstream segment or upstream element thereof may also provide an additional degree of protection for the aerosol-generating substrate during storage, as it covers, at least to some extent, the upstream end of the aerosol-generating substrate which might otherwise be exposed.

[0088] For an aerosol-generating article intended to be inserted into a cavity in an aerosol-generating device so that the aerosol-generating substrate can be heated externally within the cavity, the upstream section or its upstream element may advantageously facilitate the insertion of the upstream end of the article into the cavity. The inclusion of the upstream element may additionally protect the end of the strip of the aerosol-generating substrate during insertion of the article into the cavity, minimizing the risk of damage to the substrate.

[0089] The upstream section or its upstream element may also provide an improved appearance to the upstream end of the aerosol-generating article. In addition, if desired, the upstream section or its upstream element may be used to provide information about the aerosol-generating article, such as information about the brand, flavor, contents, or details of the aerosol-generating device intended for use with the article.

[0090] The upstream element may be a porous rod element. The upstream element may be made of a porous material or may include a plurality of openings. For example, this may be achieved by laser perforation. Preferably, the plurality of openings are evenly distributed over the cross section of the upstream element. The porosity or permeability of the upstream element may advantageously be designed to provide a specific overall resistance to draw (RTD) to the aerosol generating article without substantially affecting the filtration provided by other parts of the article.

[0091] The upstream element may be formed from a material that is impermeable to air.In such embodiments, the aerosol-generating article may be configured such that air flows into the strip of aerosol-generating substrate via suitable ventilation means provided in the packaging.

[0092] The upstream element may be formed by a solid cylindrical rod element having a filled cross section. Such a rod element may be referred to as a "plain" element. As described above, a solid rod element may be porous, but does not have a tubular form and therefore does not provide a longitudinal flow channel. The solid rod element preferably has a substantially uniform cross section.

[0093] The upstream element may be formed from a hollow tubular segment defining a longitudinal lumen providing an unrestricted flow passage.Thus, as described above, the upstream element may provide protection for the aerosol-generating substrate while having minimal impact on the overall resistance to draw (RTD) and filtration characteristics of the article.

[0094] Preferably, the diameter of the longitudinal lumen of the hollow tubular segment forming the upstream element is at least 3 mm, more preferably at least 3.5 mm, more preferably at least 4 mm, and more preferably at least 4.5 mm. Preferably, the diameter of the longitudinal lumen is maximized in order to minimize the RTD of the upstream segment or its upstream element.

[0095] Preferably, the wall thickness of the hollow tubular segment is less than 2 mm, more preferably less than 1.5 mm, and more preferably less than 1 mm.

[0096] The upstream element of the upstream section may be made of any material suitable for use in an aerosol generating article. The upstream element may, for example, be made of the same material as one of the other components of the aerosol generating article, such as a downstream filter segment or a hollow tubular cooling element. Suitable materials for forming the upstream element include filter materials, ceramics, polymeric materials, cellulose acetate, paperboard, zeolites, or an aerosol generating matrix. The upstream element may include a rod of cellulose acetate. The upstream element may include a hollow acetate tube or a paperboard tube.

[0097] Preferably, the upstream section or its upstream element has an outer diameter approximately equal to the outer diameter of the aerosol generating article. Preferably, the outer diameter of the upstream section or its upstream element is between 5 mm and 8 mm, more preferably between 5.25 mm and 7.5 mm, more preferably between 5.5 mm and 7 mm.

[0098] Preferably, the length of the upstream section or upstream element is between 2 mm and 10 mm, more preferably between 3 mm and 8 mm, more preferably between 2 mm and 6 mm. In a particularly preferred embodiment, the upstream section or upstream element has a length of 5 mm. The length of the upstream section or upstream element may advantageously be varied in order to provide a desired overall length of the aerosol-generating article. For example, in case it is desired to reduce the length of one of the other components of the aerosol-generating article, the length of the upstream section or upstream element may be increased in order to maintain the same overall length of the article.

[0099] Additionally, for articles intended for external heating, the length of the upstream section or its upstream element may be used to control the position of the aerosol-generating article within the cavity of the aerosol-generating device. This may advantageously ensure that the position of the aerosol-generating substrate within the cavity may be optimized for heating, and may also optimize the position of any ventilation.

[0100] The upstream section is preferably defined by a wrapper such as a stick wrapper. The wrapper defining the upstream section is preferably a rigid stick wrapper, for example a stick wrapper having a basis weight of at least 80 grams per square meter (gsm), or at least 100 gsm, or at least 110 gsm. This provides structural rigidity to the upstream section.

[0101] The upstream section is preferably connected to the strip of aerosol-generating substrate, and optionally at least a portion of the downstream section, by means of an overwrap as described herein.

[0102] Preferably, the aerosol generating article according to the present disclosure as described herein is suitable for use in an electrically operated aerosol generating system, wherein the aerosol generating substrate of the heated aerosol generating article is heated by an electric heat source. As described herein, an electrically operated aerosol generating system including an induction heating device may also include an aerosol generating article having an aerosol generating substrate and a receptor in thermal proximity to the aerosol generating substrate. The receptor may be in direct contact with the aerosol generating substrate and heat is transferred from the receptor to the aerosol generating substrate primarily by conduction. Examples of electrically operated aerosol generating systems with induction heating devices and aerosol generating articles with receptors are described in WO-A1-95 / 27411 and WO-A1-2015 / 177255.

[0103] The aerosol generating device may extend between the distal end and the mouth end. The aerosol generating device may include a body or housing. The body or housing of the aerosol generating device may define a device cavity or heating chamber for removably receiving an aerosol generating article at the mouth end of the device. The aerosol generating device may include a heating element or heater for heating the aerosol generating substrate when the aerosol generating article is received in the device cavity.

[0104] In other words, the aerosol-generating device may comprise a heating chamber for receiving the aerosol-generating article and a heating element arranged at or around the periphery of the heating chamber.

[0105] The device cavity may be referred to as a heating chamber of an aerosol generating device. The device cavity may extend between a distal end and an oral end or a proximal end. The distal end of the device cavity may be a closed end, and the oral end or the proximal end of the device cavity may be an open end. The oral end or the open end of the device cavity may correspond to the oral end or the distal end of the aerosol generating device. The aerosol generating device may be configured to receive an aerosol generating article through the oral end of the device or device cavity (or heating chamber). The aerosol generating device may be configured to receive an aerosol generating article via the oral end of the device or device cavity (or heating chamber). The device cavity or heating chamber may be configured to receive an aerosol generating article through or via its oral end. The aerosol generating article may be configured to be received into or in the device or device cavity (or heating chamber) through or via the oral end of the device or device cavity. The aerosol generating article may be configured to be inserted into the device or device cavity (or heating chamber) through or through the oral end of the device or device cavity. The aerosol-generating article may be inserted into the device cavity or heating chamber via an open end of the device or device cavity.The device cavity may be cylindrical in shape so as to conform to the same shape of the aerosol-generating article.

[0106] The expression "received within" may refer to the fact that a component or element is fully or partially received within another component or element. For example, the expression "the aerosol-generating article is received within the device cavity" means that the aerosol-generating article is fully 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 be adjacent to 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 proximal to the distal end of the device cavity. The distal end of the device cavity may be defined by an end wall.

[0107] The aerosol-generating article may be configured to protrude or extend beyond the mouth end of the aerosol-generating device when received within the device or device cavity (or heating chamber). The length of the aerosol-generating article may be greater than the length of the device cavity (or heating chamber). This allows the article to be easily inserted into and removed from the device, and enables the mouth end portion of the article to extend beyond the device over which a user can draw an aerosol.

[0108] The length of the device cavity can be between about 15 mm and about 80 mm. Preferably, the length of the device cavity is between about 20 mm and about 70 mm. More preferably, the length of the device cavity is between about 25 mm and about 60 mm. More preferably, the length of the device is between about 25 mm and about 50 mm.

[0109] The length of the device cavity can be between about 25 mm and about 29 mm. Preferably, the length of the device cavity is between about 25 mm and about 29 mm. More preferably, the length of the device cavity is between about 26 mm and about 29 mm. Even more preferably, the length of the device cavity is about 27 mm or about 28 mm.

[0110] The diameter of the device cavity can be between about 4 mm and about 10 mm. The diameter of the device cavity can be between about 5 mm and about 9 mm. The diameter of the device cavity can be between about 6 mm and about 8 mm. The diameter of the device cavity can be between about 6 mm and about 7.5 mm.

[0111] The diameter of the device cavity may be substantially equal to or greater than the diameter of the aerosol-generating article.The diameter of the device cavity may be the same as the diameter of the aerosol-generating article so as to establish a close fit with the aerosol-generating article.

[0112] The device cavity may be configured to establish a tight fit with an aerosol generating article received in the device cavity. Tight fit may refer to a snug fit. The aerosol generating device may include a peripheral wall. Such a peripheral wall may define the device cavity or the heating chamber. The peripheral wall defining the device cavity may be configured to engage with the aerosol generating article received in the device cavity in a tight fit, such that when the aerosol generating article is received in the device, there is substantially no gap or empty space between the peripheral wall defining the device cavity and the aerosol generating article.

[0113] This tight fit may establish an airtight fit or arrangement between the device cavity and the aerosol-generating article received therein. With this airtight arrangement, there will be substantially no gap or empty space for air to flow through between the peripheral wall defining the device cavity and the aerosol-generating article. The tight fit with the aerosol-generating article may be established along the entire length of the device cavity or along a portion of the length of the device cavity.

[0114] The aerosol generating device may include an air inlet channel extending between a channel inlet and a channel outlet. The air inlet channel may be configured to establish fluid communication between the interior of the device cavity and the exterior of the aerosol generating device. The air inlet channel of the aerosol generating device may be defined within a housing of the aerosol generating device to enable fluid communication between the interior of the device cavity and the exterior of the aerosol generating device. When the aerosol generating article is received within the device cavity, the air inlet channel may be configured to provide an airflow into the article so as to deliver the generated aerosol to a user drawing from the mouth end of the article.

[0115] The air inlet passage of the aerosol generating device may be defined within or by a peripheral wall of the housing of the aerosol generating device. In other words, the air inlet passage of the aerosol generating device may be defined within the thickness of the peripheral wall or by the inner surface of the peripheral wall, or a combination of both. The air inlet passage may be defined in part by the inner surface of the peripheral wall and may be defined in part within the thickness of the peripheral wall. The inner surface of the peripheral wall defines the peripheral boundary of the device cavity.

[0116] The inlet passage of the aerosol generating device may extend from an inlet located at the mouth or proximal end of the aerosol generating device to an outlet located distally from the mouth end of the device.The inlet passage may extend in a direction parallel to the longitudinal axis of the aerosol generating device.

[0117] The heating chamber or device cavity can be sized so that a longitudinal gap is provided between the aerosol generating article received therein and the peripheral wall defining the device cavity. Such longitudinal gap can partially or completely define the aerosol generating article received in the device. Such longitudinal gap or space can define an air inlet passage extending from the open mouth end of the device cavity to the closed distal end of the device cavity. In addition, the device housing can be configured so that air can enter the upstream end of the article when the upstream end of the article is adjacent to the distal end of the device cavity. The device housing and cavity can be such that fluid communication between the air inlet passage of the device, preferably at the distal end of the device cavity, and the upstream end of the received aerosol generating article is established. Therefore, when the inserted aerosol generating article is sucked, air can enter the aerosol generating device through the air inlet passage and flow to the distal end of the device cavity and enter the upstream end of the received article.

[0118] The heater may be any suitable type of heater. Preferably, in the present disclosure, the heater is an external heater.

[0119] The heating element of such an aerosol generating device may be of any suitable form to conduct heat. The heating of the aerosol generating substrate may be achieved internally, externally or internally and externally. The heating element may be a heater blade or pin adapted to be inserted into the aerosol generating substrate so that the substrate is heated from the inside. The heating element may preferably partially or completely surround the substrate and externally heat the substrate circumferentially from the outside.

[0120] Preferably, the heater may externally heat the aerosol-generating article when the aerosol-generating article is received in the aerosol-generating device. Such an external heater may confine or surround the aerosol-generating article when the aerosol-generating article is inserted into or received in the aerosol-generating device. Preferably, the length of the heater substantially corresponds to the length of the aerosol-generating substrate of the aerosol-generating article that the aerosol-generating device is configured to receive.

[0121] The heater may be arranged to heat an outer surface of the aerosol-generating substrate. The heater may be arranged to be inserted into the aerosol-generating substrate when the aerosol-generating substrate is received in the cavity. The heater may be located within the device cavity or a heating chamber.

[0122] The heater may include at least one heating element. The at least one heating element may be any suitable type of heating element. The device may include only one heating element. The device includes a plurality of heating elements. The heater may include at least one resistive heating element. Preferably, the heater includes a plurality of resistive heating elements. Preferably, the resistive heating elements are electrically connected in a parallel arrangement. Advantageously, providing a plurality of resistive heating elements electrically connected in a parallel arrangement may facilitate the delivery of the desired power to the heater while reducing or minimizing the voltage required to provide the desired power. Advantageously, reducing or minimizing the voltage required to operate the heater may facilitate reducing or minimizing the physical size of the power supply.

[0123] The heater may include an induction heating device. The induction heating device may include an induction source and a susceptor, which may be arranged outside the aerosol generating substrate or inside the aerosol generating substrate. The induction source may include an inductor coil and a power supply, which is configured to provide a high-frequency oscillating current to the inductor coil. As used herein, a high-frequency oscillating current means an oscillating current with a frequency between about 500 kHz and about 30 MHz. Advantageously, the heater may include a DC / AC inverter, which is used to convert a DC current supplied by a DC power supply into an alternating current. The inductor coil may be arranged to generate a high-frequency oscillating electromagnetic field when receiving a high-frequency oscillating current from the power supply. The inductor coil may be arranged to generate a high-frequency oscillating electromagnetic field in a device cavity. The inductor coil may substantially define the device cavity. The inductor coil may extend at least partially along the length of the device cavity.

[0124] 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 including a material capable of converting electromagnetic energy into heat. When the susceptor element is located in an alternating electromagnetic field, the susceptor is heated. The heating of the susceptor element may be the result of at least one of hysteresis losses and eddy currents induced in the susceptor, depending on the electrical and magnetic properties of the susceptor material.

[0125] The susceptor element may be arranged such that when the aerosol generating article is received in the cavity of the aerosol generating device, the oscillating electromagnetic field generated by the inductor coil induces a current in the susceptor element, thereby causing the susceptor element to heat up. Preferably, the aerosol generating device is capable of generating a fluctuating electromagnetic field having a magnetic field strength (H field strength) of between 1 kiloamperes per meter and 5 kiloamperes per meter (kA / m), preferably between 2 kA / m and 3 kA / m, for example about 2.5 kA / m. The electrically operated aerosol generating device is preferably capable of generating a fluctuating electromagnetic field having a frequency of between 1 MHz and 30 MHz, for example between 1 MHz and 10 MHz, for example between 5 MHz and 7 MHz.

[0126] The susceptor element may be positioned to contact the aerosol generating substrate. The susceptor element may be located in the aerosol generating device. The susceptor element may be located in or around the periphery of the device cavity. The aerosol generating device may include only one susceptor element. The aerosol generating device may include a plurality of susceptor elements. The susceptor element is preferably arranged to externally heat the aerosol generating substrate. When the aerosol generating article is received in the heating chamber, the susceptor element may define the aerosol generating article.

[0127] The susceptor element may comprise any suitable material. The susceptor element may be formed of any material that can be inductively heated to a temperature sufficient to release volatile compounds from the aerosol generating substrate. Suitable materials for the elongated susceptor element include graphite, molybdenum, silicon carbide, stainless steel, niobium, aluminum, nickel, nickel-containing compounds, titanium, and metal material composites. Some susceptor elements include metal or carbon. Advantageously, the susceptor element may include or consist of a ferromagnetic material, such as ferritic iron, ferromagnetic alloys (e.g., ferromagnetic steel or stainless steel), ferromagnetic particles, and ferrites. Suitable susceptor elements may be aluminum or include aluminum. The susceptor element preferably comprises about greater than 5%, preferably greater than 20%, more preferably greater than 50%, or greater than 90% ferromagnetic or paramagnetic material. Some elongated susceptor elements may be heated to a temperature in excess of 250 degrees Celsius.

[0128] The susceptor element may comprise a non-metallic core with a metallic layer disposed thereon.For example, the susceptor element may comprise a metallic track formed on the outer surface of a ceramic core or substrate.

[0129] The aerosol generating device may comprise at least one resistive heating element and at least one inductive heating element.The aerosol generating device may comprise a combination of resistive heating elements and inductive heating elements.

[0130] During use, the heater can be controlled to operate within a limited operating temperature range below the maximum operating temperature. An operating temperature range between about 150 degrees Celsius and about 300 degrees Celsius in the heating chamber (or device cavity) is preferred. The operating temperature range of the heater can be between about 150 degrees Celsius and about 250 degrees Celsius.

[0131] Preferably, the operating temperature range of the heater may be between about 150 degrees Celsius and about 200 degrees Celsius. More preferably, the operating temperature range of the heater may be between about 180 degrees Celsius and about 200 degrees Celsius. In particular, it has been found that optimal and consistent aerosol delivery can be achieved when using an aerosol generating device with an external heater having an operating temperature range between about 180 degrees Celsius and about 200 degrees Celsius, wherein the aerosol generating article has a relatively low RTD (e.g., less than 15 mmHg) as described in the present disclosure. 2 O downstream segment RTD).

[0132] As described above, the hollow tubular substrate element of an aerosol-generating article according to the present disclosure may advantageously be modified so that the length substantially matches the longitudinal dimension of a heating element of an aerosol-generating system intended for heating the aerosol-generating article. This may ensure that the hollow tubular substrate element is heated substantially along its entire length, so that aerosol generation from the aerosol-generating substrate may be maximized.

[0133] 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, such as a lithium cobalt battery, a lithium iron phosphate battery, or a 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 need to be recharged and may have a capacity that allows storage of enough energy for one or more user operations (e.g., one or more aerosol generating experiences). For example, the power source may have sufficient capacity to allow continuous heating of the aerosol generating substrate for a period of about six minutes, corresponding to the typical time spent smoking a conventional cigarette, or for a period of time that is a multiple of six minutes. In another example, the power source may have sufficient capacity to allow a predetermined number of puffs or discontinuous activation of the heater.

[0134] As described above, the aerosol generating device comprises an airflow directing element extending along the device cavity or heating chamber.The airflow directing element preferably extends along a central longitudinal axis of the heating chamber.

[0135] The aerosol generating article according to the present disclosure preferably comprises an open upstream end. Such an open upstream end may be defined by an open upstream end of an aerosol generating substrate of the aerosol generating article. Such an open upstream end may be defined by an open upstream end of an upstream section of the aerosol generating article. For example, a hollow tubular element of the upstream section or a hollow tubular aerosol generating substrate may define the open upstream end of the article. In addition, the hollow tubular substrate and the hollow tubular upstream element (if present) define a longitudinally extending cavity, which is arranged to receive the airflow guiding element when the aerosol generating article is inserted into the heating chamber of the aerosol generating device.

[0136] When the article according to the present disclosure is inserted into the heating chamber, the airflow directing element preferably extends longitudinally into the longitudinal substrate cavity. The main airflow path or channel can be defined between the outer surface of the airflow directing element and the inner surface of the aerosol generating substrate. The width or diameter of a portion of the airflow directing element can therefore be less than the diameter of the substrate cavity.

[0137] The airflow directing element may extend longitudinally from the device housing into the heating chamber. The airflow directing element may extend longitudinally from a portion of the device housing defining the distal end of the heating chamber. The airflow directing element preferably extends in a longitudinal direction toward the mouth end of the heating chamber. The airflow directing element preferably extends in a longitudinal direction substantially parallel to the central axis of the heating chamber. The airflow directing element preferably extends in a longitudinal direction substantially aligned with the central axis of the heating chamber.

[0138] The external heater of the aerosol generating device may partially or fully surround an airflow directing element extending along the heating chamber.

[0139] The aerosol generating device may comprise a base support element from which the airflow directing element may extend.The base support element may be coupled to a distal end of the device cavity.

[0140] The maximum outer diameter of the base support element may be approximately equal to the outer diameter of the aerosol-generating substrate.The maximum outer diameter of the base support element may be approximately equal to the inner diameter of the aerosol-generating substrate.The maximum outer diameter of the base support element may be approximately equal to the inner diameter of the hollow tubular section of the upstream section.

[0141] The base support element may have a disc or plate shape, preferably a cylindrical shape. Preferably, the base support element is porous or includes at least one orifice. This enables fluid communication to be established between the exterior of the aerosol generating article and the interior of the aerosol generating substrate through the base support element. The periphery of the base support element may be chamfered. This may facilitate engagement of the base support element with the hollow upstream end of the aerosol generating article when the aerosol generating article is inserted into the device cavity. The chamfered periphery of the base support element may be used as a centering guide for insertion of the article into the aerosol generating device, thereby ensuring that the inserted article is centered on the central longitudinal axis of the device cavity.

[0142] The airflow directing element preferably comprises an elongated body extending longitudinally into the heating chamber. The airflow directing element preferably comprises an elongated body extending from an upstream proximal end of the airflow directing element to a downstream distal end of the airflow directing element. The airflow directing element preferably comprises an elongated body extending from a fixed end of the airflow directing element to a free end of the airflow directing element. The downstream end or distal end of the airflow directing element may be closer to the mouth end or distal end of the aerosol generating device than the upstream end or proximal end of the airflow directing element.

[0143] The upstream end of the airflow directing element may be coupled to the base support element. The central longitudinal axis of the airflow directing element may be aligned with the central longitudinal axis of the base support element. The airflow directing element preferably includes an elongated body extending from a fixed end of the airflow directing element to a free end of the airflow directing element. The end of the airflow directing element coupled to the base support element may define the fixed end of the airflow directing element, while the opposite end may be the free end of the airflow directing element.

[0144] The length of the base support element may be at least about 0.5 mm. The length of the base support element may be at least about 1 mm. The length of the base support element may be at least about 1.5 mm.

[0145] The length of the base support element may be up to about 5 mm. The length of the base support element may be up to about 4 mm. The length of the base support element may be up to about 3 mm.

[0146] The elongated body of the airflow guiding element may be bar-shaped or conical.The elongated body of the airflow guiding element preferably comprises a hollow body or tube defining a longitudinal cavity.The elongated body of the airflow guiding element preferably comprises a hollow cylindrical tube defining a longitudinal cavity.

[0147] The downstream end of the hollow body may be closed such that air cannot flow into the matrix cavity via the interior of the hollow body.

[0148] The airflow directing element may include an airflow inlet at a first location and an airflow outlet at a second location downstream of the first location such that an airflow path is defined within and along the airflow directing element.

[0149] The downstream end of the hollow body may be porous or may be provided with one or more perforations, apertures, inlets or outlets such that fluid communication is established between the interior of the hollow body and the matrix cavity and a secondary gas flow path is defined into the matrix cavity.

[0150] The downstream end of hollow body can be open, makes to set up fluid between the inside of hollow body and the matrix cavity and is communicated with and limits the secondary airflow path in the airflow guiding element.If the airflow guiding element spans the whole length of matrix cavity, then the secondary airflow path can directly guide air to the downstream section of goods.If the airflow guiding element extends less than 100% along the length of matrix cavity, then the secondary airflow path can guide air in the matrix cavity of goods.

[0151] The upstream end of the hollow body can also be open. The base support element is preferably porous or preferably includes at least one orifice, so that fluid communication is established between the outside of the aerosol generating article and the inside of the aerosol generating substrate via the base support element. The base support element can include a central orifice aligned with the open upstream end of the airflow directing element. This allows air to flow through the base support element and enter the substrate cavity via the central secondary airflow path defined in the airflow directing element. The main airflow path or passage can be defined between the inner surface of the aerosol generating substrate and the outer surface of the airflow directing element. In other words, the main airflow path or passage can define the airflow directing element.

[0152] In the case where the airflow directing element comprises a hollow body, perforations or holes extending through the peripheral wall of the hollow body that limits the longitudinal cavity can be provided.The peripheral wall of the hollow body can be porous.This one or more peripheral perforations can track a specific path along or around the hollow body of the airflow directing element.This one or more peripheral perforations can track a linear, spiral, curved or wavy path along or around the hollow body of the airflow directing element.This beneficially allows to establish fluid communication between the inside of the hollow body and the substrate cavity so that one or more secondary airflow paths entering the substrate cavity are limited.Air can flow through the base support element into the hollow body or the pipe of the airflow directing element and leave into the substrate cavity by the peripheral wall of the hollow body.The air passing through the hollow body can also leave and enter the substrate cavity via the opening at the downstream end of the hollow body.This secondary airflow can provide dilution and cooling function for the main airflow that travels downstream between the inner surface of the airflow directing element and the aerosol generating element.

[0153] The width or diameter of the airflow directing element can be uniform along its length. The width or diameter of the airflow directing element can vary along its length. The internal diameter of the airflow directing element can be at least about 0.5mm. The internal diameter of the airflow directing element can be at least about 1mm. The internal diameter of the airflow directing element can be at least about 1.5mm. The internal diameter of the airflow directing element can be at least about 2mm. The internal diameter of the airflow directing element can be up to about 5mm. The internal diameter of the airflow directing element can be up to about 4mm. The size of the hollow cavity defined in the airflow directing element defines the size of the secondary airflow passage or path and is arranged to enter the dilution or cooling air of the substrate cavity during use.

[0154] The airflow directing element may be textured. The airflow directing element may have an uneven outer surface or a raised outer surface. The airflow directing element may include raised elements on its outer surface. The airflow directing element may include one or more grooves, recesses, bumps, protrusions, ridges or protrusions disposed on its outer surface. By having a textured or uneven outer surface, the airflow directing element is able to disturb the air flowing around it so as to form local turbulence, which can enhance mixing of the air with the released aerosol-forming components.

[0155] The airflow directing element may include a plurality or a series of aligned segments forming an elongated body. Each segment may have any shape. Each of the segments may be pyramidal, bar-shaped, cylindrical, conical, circular, spherical or hemispherical. For example, the airflow directing element may include a plurality of aligned conical segments to form an elongated body.

[0156] The airflow directing element may include a core elongated portion (according to the above-mentioned elongated body) and at least one extension portion positioned along the core portion. At least one extension portion may include a bump, a protrusion or a protrusion arranged on the outer surface of the core portion. At least one extension portion may be formed on the outer surface of the core portion. At least one extension portion may define a raised surface on the airflow directing element, preferably on its core portion. At least one extension portion may extend outwardly from the core portion (in other words, away from the central axis of the core portion). At least one extension portion may extend radially from the core portion. At least one extension portion may extend longitudinally along the core portion. At least one extension portion may extend completely or partially circumferentially around the core portion.

[0157] The airflow directing element may comprise at least two extensions positioned along the core portion. Each extension may be located at a respective longitudinal or axial position along the core portion. The airflow directing element may comprise three extensions positioned along the core portion.

[0158] The extension portion may be substantially shaped in the form of a sphere, a hemisphere, a cylinder or a ring. By providing one or more extension portions along the core portion of the airflow directing element, the width or diameter of the airflow directing element may vary along its length so as to promote local airflow separation from the outer surface of the airflow directing element. This in turn may promote the formation of a local turbulent airflow between the airflow directing element and the inner surface of the aerosol generating substrate, thereby improving aerosol generation due to enhanced mixing of air with aerosol-forming components released from the heated aerosol generating substrate.

[0159] Each extension of the airflow directing element may extend a certain length along the core portion. The length of each extension or extension of the airflow directing element may be at least about 5% of the total length of the airflow directing element. The length of each extension or extension of the airflow directing element may be at least about 10% of the total length of the airflow directing element. The length of each extension or extension of the airflow directing element may be at least about 15% of the total length of the airflow directing element. The length of each extension or extension of the airflow directing element may be at least about 20% of the total length of the airflow directing element. The length of each extension or extension of the airflow directing element may be at least about 25% of the total length of the airflow directing element.

[0160] The length of each extension or extension of the airflow directing element may be up to about 75% of the total length of the airflow directing element. The length of each extension or extension of the airflow directing element may be up to about 60% of the total length of the airflow directing element. The length of each extension or extension of the airflow directing element may be up to about 50% of the total length of the airflow directing element. The length of each extension or extension of the airflow directing element may be up to about 40% of the total length of the airflow directing element. The length of each extension or extension of the airflow directing element may be up to about 35% of the total length of the airflow directing element.

[0161] Where a plurality of extensions are provided, each extension may have a different length. For example, the airflow directing element may include three extensions arranged in sequence along the core portion, the first extension may extend along approximately 15% of the total length of the airflow directing element, and the other two extensions may extend along approximately 35% of the total length of the airflow directing element.

[0162] Advantageously, depending on the size of the extension relative to the airflow direction element, the location of the or each extension along the airflow direction element, and the distance between sequential or adjacent extensions, the amount of disturbance and turbulence generated in air flowing around the airflow direction element can be tailored.

[0163] The extension portion may be provided at an upstream end of the airflow guiding element or a core portion thereof.The extension portion may be provided at a downstream end of the airflow guiding element or a core portion thereof.

[0164] Sequential or adjacent extensions may be spaced apart from one another so as to define gaps between them. The extensions may be uniformly spaced apart from one another. Mainly when the cross-section of the extensions is uniform along their length (such as a cylinder or ring), providing gaps between sequential or adjacent extensions defines a section of the main airflow channel in which the cross-sectional area increases, thereby allowing air to be locally decelerated after flowing over an upstream extension or before flowing over a downstream extension. The outer surface of the core portion may be exposed through such gaps.

[0165] The base support element and the airflow directing element can be manufactured separately and then connected to each other before assembling the aerosol generating device. The base support element and the airflow directing element can be formed integrally with each other, for example, by extrusion or by injection molding. Similarly, the core portion and any extension of the airflow directing element can be manufactured separately and then connected to each other before assembling the aerosol generating device. The core portion and any extension of the airflow directing element can be formed integrally with each other, for example, by extrusion or by injection molding. The extension can be manufactured separately from the core portion and can be subsequently assembled to the core portion. For example, the extension can be an annular or cylindrical element mounted on the core portion and connected to the core portion. For example, such an annular or cylindrical element can slide onto the core portion and engage with the core portion by means of adhesion or interference fit. Since the aerosol generating device is expected to be reused by inserting and removing the aerosol generating article, the airflow directing element structure that is basically resistant to deformation in structure is preferably used for the aerosol generating device.

[0166] The material of the base support element and the material of the airflow directing element may be the same. The airflow directing element, the base support element, or both may be formed of non-metallic materials. The airflow directing element, the base support element, or both may not include metallic materials. The airflow directing element, the base support element, or both may be formed of cardboard. The airflow directing element, the base support element, or both may be formed of paper-based materials. The airflow directing element, the base support element, or both may be formed of paper. The airflow directing element, the base support element, or both may be formed of polymer materials. The airflow directing element, the base support element, or both may be formed of plastic materials. The airflow directing element, the base support element, or both may be formed of bioplastic materials. The airflow directing element, the base support element, or both may be formed of cellulose acetate. The materials mentioned in the present disclosure can provide suitable resistance to deformation or compression while providing base support elements and airflow directing elements that can be manufactured cost-effectively.

[0167] The airflow directing element, the base support element or both may comprise a thermally conductive material.This may facilitate heat transfer to the inner surface of the aerosol-generating substrate, particularly when heated by an external heating element.

[0168] The airflow directing element may include an outer layer or coating at least partially disposed on an outer surface, preferably disposed on an outer surface of the airflow directing element body. The outer layer or coating may include one or more of an aerosol former, a flavoring agent, and an additional aerosol generating substrate. Such aerosol former, flavoring agent, and additional aerosol generating substrate of the outer layer or coating may conform to the aerosol former, flavoring agent, and aerosol generating substrate as described in the present disclosure, respectively.

[0169] The length of the air flow guiding element preferably corresponds to the amount by which the air flow guiding element extends into the substrate cavity.

[0170] The length of the airflow directing element may be at least about 1 mm. The length of the airflow directing element may be at least about 3 mm. The length of the airflow directing element may be at least about 5 mm. The length of the airflow directing element may be at least about 6 mm. The length of the airflow directing element may be at least about 8 mm. The length of the airflow directing element may be at least about 9 mm.

[0171] The length of the airflow directing element may be up to about 30 mm. The length of the airflow directing element may be up to about 25 mm. The length of the airflow directing element may be up to about 20 mm. The length of the airflow directing element may be up to about 15 mm. The length of the airflow directing element may be up to about 12 mm. The length of the airflow directing element may be up to about 10 mm.

[0172] The length of the airflow guiding element can be between about 1mm and about 30mm, between about 3mm and about 30mm, between about 5mm and about 30mm, between about 6mm and about 30mm, between about 8mm and about 30mm, or preferably between about 9mm and about 30mm. The length of the airflow guiding element can be between about 1mm and about 25mm, between about 3mm and about 25mm, between about 5mm and about 25mm, between about 6mm and about 25mm, between about 8mm and about 25mm, or preferably between about 9mm and about 25mm. The length of the airflow guiding element can be between about 1mm and about 20mm, between about 3mm and about 20mm, between about 5mm and about 20mm, between about 6mm and about 20mm, between about 8mm and about 20mm, or preferably between about 9mm and about 20mm. The length of the airflow guiding element can be between about 1mm and about 15mm, between about 3mm and about 15mm, between about 5mm and about 15mm, between about 6mm and about 15mm, between about 8mm and about 15mm, or preferably between about 9mm and about 15mm. The length of the airflow guiding element can be between about 1mm and about 12mm, between about 3mm and about 12mm, between about 5mm and about 12mm, between about 6mm and about 12mm, between about 8mm and about 12mm, or preferably between about 9mm and about 12mm. The length of the airflow guiding element can be between about 1mm and about 10mm, between about 3mm and about 10mm, between about 5mm and about 10mm, between about 6mm and about 10mm, between about 8mm and about 10mm, or preferably between about 9mm and about 10mm.

[0173] The length of the airflow directing element may be at least about 10% of the length of the diameter of the heating chamber (or device cavity). The length of the airflow directing element may be at least about 10% of the length of the diameter of the heating chamber (or device cavity). The length of the airflow directing element may be at least about 20% of the length of the diameter of the heating chamber (or device cavity). The length of the airflow directing element may be at least about 25% of the length of the diameter of the heating chamber (or device cavity). The length of the airflow directing element may be at least about 30% of the length of the diameter of the heating chamber (or device cavity). The length of the airflow directing element may be at least about 40% of the length of the diameter of the heating chamber (or device cavity). The length of the airflow directing element may be at least about 50% of the length of the diameter of the heating chamber (or device cavity).

[0174] The length of the airflow directing element defines the length of the restricted airflow path or passage defined between the outer surface of the airflow directing element and the inner surface of the aerosol generating substrate. It can be appreciated that a balance can be struck between providing a relatively long airflow directing element to define a relatively long restricted airflow path and the manufacturing cost of providing such a long airflow directing element. Ideally, the length of the airflow directing element can be at least about 50%, preferably at least about 60%, of the length of the diameter of the heating chamber (or device cavity).

[0175] The length of the airflow directing element may be at least about 10% of the length of the aerosol generating substrate or substrate cavity. The length of the airflow directing element may be at least about 25% of the length of the aerosol generating substrate or substrate cavity. The length of the airflow directing element may be at least about 30% of the length of the aerosol generating substrate or substrate cavity. The length of the airflow directing element may be at least about 50% of the length of the aerosol generating substrate or substrate cavity. The length of the airflow directing element may be at least about 60% of the length of the aerosol generating substrate or substrate cavity. The length of the airflow directing element may be at least about 75% of the length of the aerosol generating substrate or substrate cavity. The length of the airflow directing element may be at least about 80% of the length of the aerosol generating substrate or substrate cavity. The length of the airflow directing element may be at least about 90% of the length of the aerosol generating substrate or substrate cavity. The length of the airflow directing element may be at least about 100% of the length of the aerosol generating substrate or substrate cavity.

[0176] The length of the airflow directing element defines the length of the restricted airflow path or passage defined between the outer surface of the airflow directing element and the inner surface of the aerosol generating substrate. It can be appreciated that a balance can be struck between providing a relatively long airflow directing element in order to define a relatively long restricted airflow path and the manufacturing cost of providing such a long airflow directing element. Ideally, the length of the airflow directing element can be at least about 50%, preferably at least about 60%, of the length of the aerosol generating substrate or substrate cavity.

[0177] Preferably, the center or longitudinal axis of the airflow directing element is aligned with the center or longitudinal axis of the aerosol generating substrate. Preferably, the airflow directing element is axially symmetrical. This can ensure that the restricted airflow channel defined around the airflow directing element and between the airflow directing element and the inner surface of the aerosol generating substrate is axially symmetrical.

[0178] The airflow directing element has a maximum outer diameter. One or more raised surfaces or extensions of the airflow directing element may define the maximum outer diameter or width of the airflow directing element. Thus, the diameter or width of the airflow directing element may vary or oscillate along the length of the airflow directing element.

[0179] In the case where the outer diameter or width of the airflow guiding element changes, the portion of the airflow guiding element whose outer diameter or width corresponds to the maximum width or outer diameter of the airflow guiding element is preferably positioned away from the upstream end or proximal end of the airflow guiding element or downstream thereof. This ensures that the air flowing around the airflow guiding element encounters a cross-sectional area reduction of the airflow channel defined between the outer surface of the airflow guiding element and the inner surface of the aerosol generating substrate received in the device cavity due to the increase in the diameter of the airflow guiding element (further along the airflow guiding element and not at the base (or upstream end or proximal end) of the airflow guiding element). This increase in diameter or width may interfere with the airflow and push the air closer to the inner surface of the aerosol generating substrate, thereby promoting the formation of local turbulent airflow and local airflow acceleration between the airflow guiding element (particularly at the position where the diameter or width increases) and the inner surface of the aerosol generating substrate. Due to the enhanced mixing of air with the aerosol forming components released from the heated aerosol generating substrate, this can improve aerosol generation.

[0180] The maximum outer diameter or width of the airflow directing element may be at least about 1 mm. The maximum outer diameter or width of the airflow directing element may be at least about 2 mm. The maximum outer diameter or width of the airflow directing element may be at least about 2.5 mm. The maximum outer diameter or width of the airflow directing element may be at least about 3 mm.

[0181] The maximum outer diameter or width of the airflow directing element may be at least about 8 mm. The maximum outer diameter or width of the airflow directing element may be at least about 7.5 mm. The maximum outer diameter or width of the airflow directing element may be at least about 7 mm. The maximum outer diameter or width of the airflow directing element may be at least about 6 mm.

[0182] The maximum outer diameter or width of the airflow guiding element can be between about 1mm and about 8mm, between about 2mm and about 8mm, between about 2.5mm and about 8mm, or preferably between about 3mm and about 8mm. The maximum outer diameter or width of the airflow guiding element can be between about 1mm and about 7.5mm, between about 2mm and about 7.5mm, between about 2.5mm and about 7.5mm, or preferably between about 3mm and about 7.5mm. The maximum outer diameter or width of the airflow guiding element can be between about 1mm and about 7mm, between about 2mm and about 7mm, between about 2.5mm and about 7mm, or preferably between about 3mm and about 7mm. The maximum outer diameter or width of the airflow guiding element can be between about 1mm and about 6mm, between about 2mm and about 6mm, between about 2.5mm and about 6mm, or preferably between about 3mm and about 6mm.

[0183] The maximum outer diameter or width of the airflow directing element may be at least about 20% of the diameter of the heating chamber (or device cavity). The maximum outer diameter or width of the airflow directing element may be at least about 35% of the diameter of the heating chamber (or device cavity). The maximum outer diameter or width of the airflow directing element may be at least about 40% of the diameter of the heating chamber (or device cavity). The maximum outer diameter or width of the airflow directing element may be at least about 50% of the diameter of the heating chamber (or device cavity). The maximum outer diameter or width of the airflow directing element may be at least about 60% of the diameter of the heating chamber (or device cavity).

[0184] The maximum outer diameter or width of the airflow directing element can be at least about 25% of the diameter of the internal diameter of the aerosol generating substrate or the substrate cavity. The maximum outer diameter or width of the airflow directing element can be at least about 40% of the diameter of the internal diameter of the aerosol generating substrate or the substrate cavity. The maximum outer diameter or width of the airflow directing element can be at least about 50% of the diameter of the internal diameter of the aerosol generating substrate or the substrate cavity. The maximum outer diameter or width of the airflow directing element can be at least about 60% of the diameter of the internal diameter of the aerosol generating substrate or the substrate cavity. The maximum outer diameter or width of the airflow directing element can be at least about 75% of the diameter of the internal diameter of the aerosol generating substrate or the substrate cavity.

[0185] A portion of an airflow directing element having a diameter corresponding to the maximum outer diameter or width of the airflow directing element may be positioned away from (or downstream of) the base or upstream end of the airflow directing element. A portion of an airflow directing element having a diameter corresponding to the maximum outer diameter or width of the airflow directing element may be positioned away from (or downstream of) the base or upstream end of the airflow directing element by at least about 10% of the length of the airflow directing element. A portion of an airflow directing element having a diameter corresponding to the maximum outer diameter or width of the airflow directing element may be positioned away from (or downstream of) the base or upstream end of the airflow directing element by at least about 20% of the length of the airflow directing element. A portion of an airflow directing element having a diameter corresponding to the maximum outer diameter or width of the airflow directing element may be positioned away from (or downstream of) the base or upstream end of the airflow directing element by at least about 25% of the length of the airflow directing element. A portion of an airflow directing element having a diameter corresponding to the maximum outer diameter or width of the airflow directing element may be positioned away from (or downstream of) the base or upstream end of the airflow directing element by at least about 50% of the length of the airflow directing element.

[0186] The diameter or any diameter of the portion of the air flow guiding element upstream of the portion of the air flow guiding element whose diameter corresponds to the maximum outer diameter or width of the air flow guiding element is preferably smaller than (or does not exceed) the maximum outer diameter or width of the air flow guiding element.

[0187] The airflow directing element may have a minimum outer diameter. For an airflow directing element with a uniform outer diameter or width, the diameter or width of the airflow directing element may correspond to the maximum outer diameter or width or the minimum outer diameter or width. The core portion of the airflow directing element may define the minimum outer diameter or width of the airflow directing element.

[0188] The minimum outer diameter or width of the airflow directing element may be at least about 0.5 mm. The minimum outer diameter or width of the airflow directing element may be at least about 1.5 mm. The minimum outer diameter or width of the airflow directing element may be at least about 2.5 mm. The minimum outer diameter or width of the airflow directing element may be at least about 3 mm.

[0189] The minimum outer diameter or width of the airflow directing element may be at least about 8 mm. The minimum outer diameter or width of the airflow directing element may be at least about 7.5 mm. The minimum outer diameter or width of the airflow directing element may be at least about 7 mm. The minimum outer diameter or width of the airflow directing element may be at least about 6 mm.

[0190] The minimum outer diameter or width of the airflow guiding element can be between about 0.5mm and about 8mm, between about 1.5mm and about 8mm, between about 2.5mm and about 8mm, or preferably between about 3mm and about 8mm. The minimum outer diameter or width of the airflow guiding element can be between about 0.5mm and about 7.5mm, between about 1.5mm and about 7.5mm, between about 2.5mm and about 7.5mm, or preferably between about 3mm and about 7.5mm. The minimum outer diameter or width of the airflow guiding element can be between about 0.5mm and about 7mm, between about 1.5mm and about 7mm, between about 2.5mm and about 7mm, or preferably between about 3mm and about 7mm. The minimum outer diameter or width of the airflow guiding element can be between about 1mm and about 6mm, between about 2mm and about 6mm, between about 2.5mm and about 6mm, or preferably between about 3mm and about 6mm.

[0191] The minimum outer diameter or width of the airflow directing element may be at least about 5% of the diameter of the heating chamber (or device cavity). The minimum outer diameter or width of the airflow directing element may be at least about 10% of the diameter of the heating chamber (or device cavity). The minimum outer diameter or width of the airflow directing element may be at least about 20% of the diameter of the heating chamber (or device cavity). The minimum outer diameter or width of the airflow directing element may be at least about 25% of the diameter of the heating chamber (or device cavity). The minimum outer diameter or width of the airflow directing element may be at least about 40% of the diameter of the heating chamber (or device cavity). The minimum outer diameter or width of the airflow directing element may be at least about 50% of the diameter of the heating chamber (or device cavity).

[0192] The minimum outer diameter or width of the airflow directing element can be at least about 10% of the diameter of the internal diameter of the aerosol generating substrate or the substrate cavity. The minimum outer diameter or width of the airflow directing element can be at least about 20% of the diameter of the internal diameter of the aerosol generating substrate or the substrate cavity. The minimum outer diameter or width of the airflow directing element can be at least about 25% of the diameter of the internal diameter of the aerosol generating substrate or the substrate cavity. The minimum outer diameter or width of the airflow directing element can be at least about 40% of the diameter of the internal diameter of the aerosol generating substrate or the substrate cavity. The minimum outer diameter or width of the airflow directing element can be at least about 50% of the diameter of the internal diameter of the aerosol generating substrate or the substrate cavity. The minimum outer diameter or width of the airflow directing element can be at least about 60% of the diameter of the internal diameter of the aerosol generating substrate or the substrate cavity.

[0193] The maximum outer diameter or width of airflow directing element can be about 100% of the internal diameter of aerosol generating substrate or the diameter of substrate cavity.Therefore, the part of airflow directing element can contact with aerosol generating substrate.The part of extension or convex portion of airflow directing element can contact with aerosol generating substrate.Set the size of airflow directing element to contact aerosol generating substrate and can promote airflow directing element to be aligned in the center with substrate cavity and can help airflow directing element to be maintained in substrate cavity.

[0194] The airflow directing element may extend along the central axis of the device cavity.The airflow directing element may extend along the central axis of the substrate cavity.A longitudinal gap or space may be defined between an outer surface of the airflow directing element and a peripheral wall of the device defining the heating chamber.

[0195] When the article is received in the heating chamber, the longitudinal gap or space can be limited between the outer surface of the airflow directing element and the inner circumferential surface of the aerosol generating substrate. The outer surface of the airflow directing element or a part thereof can be spaced apart from the inner surface of the substrate cavity so that the airflow channel is limited between the outer surface of the airflow directing element and the inner surface of the aerosol generating substrate. Preferably, the airflow channel of this limitation can be referred to as the main airflow channel or the restricted airflow channel.

[0196] The airflow channel is preferably annular in shape. In other words, the gap or space between the airflow directing element and the inner surface of the aerosol-generating substrate may define a substantially annular chamber or channel.

[0197] The distance between the outer surface of the airflow directing element and the inner surface of the aerosol generating substrate may define the height or thickness of the main airflow channel or the restricted airflow channel. The height or thickness of the airflow channel may vary longitudinally or circumferentially or both longitudinally and circumferentially, limited by the local diameter or width of the airflow directing element at specific longitudinal and circumferential positions along the elongated body of the airflow directing element.

[0198] The maximum thickness of the airflow channel may be at least about 0.25 mm. The maximum thickness of the airflow channel may be at least about 0.5 mm. The maximum thickness of the airflow channel may be at least about 1 mm. The maximum thickness of the airflow channel may be at least about 1.5 mm.

[0199] The minimum thickness of the airflow channel can be at least about 0mm. In other words, a part of the airflow directing element can be in contact with the aerosol generating substrate so that there is no distance or gap between such part of the airflow directing element and the aerosol generating substrate. The minimum thickness of the airflow channel can be at least about 0.25mm. The minimum thickness of the airflow channel can be at least about 0.5mm. The minimum thickness of the airflow channel can be at least about 1.5mm. As described herein, when the aerosol generating article is received in the heating chamber of the device, the airflow directing element extends longitudinally into the substrate cavity. In other words, the airflow directing element is received in the aerosol generating substrate of the aerosol generating article. The airflow directing element may not contact the inner surface of the aerosol generating substrate. Along its entire length, the airflow directing element may not contact the inner surface of the aerosol generating substrate. In other words, any part of the outer surface of the airflow directing element does not contact the inner surface of the aerosol generating substrate. This makes it possible to define a thicker and less obstructed airflow channel, so that more airflow can travel between the inner surface of the aerosol generating substrate and the airflow directing element.

[0200] The maximum thickness of the airflow channel can be up to about 6 mm. The maximum thickness of the airflow channel can be up to about 5 mm. The maximum thickness of the airflow channel can be up to about 3 mm. The maximum thickness of the airflow channel can be up to about 2.5 mm.

[0201] The minimum thickness of the airflow channel may be up to about 6 mm. The minimum thickness of the airflow channel may be up to about 5 mm. The minimum thickness of the airflow channel may be up to about 3 mm. The minimum thickness of the airflow channel may be up to about 2.5 mm.

[0202] For an airflow directing element having a substantially uniform diameter or width along its length, the thickness or height of the airflow channel may be uniform such that the minimum thickness and maximum thickness of the airflow channel are substantially identical.

[0203] The airflow directing element may be or may include a susceptor element configured to generate heat when placed in an oscillating electromagnetic field.

[0204] In the aerosol generating article of the present disclosure, an aerosol generating substrate comprising a hollow tubular substrate element is combined with a downstream section located downstream of the aerosol generating substrate. The downstream section is preferably located immediately downstream of the aerosol generating substrate. Preferably, the downstream section of the aerosol generating article extends between the aerosol generating substrate and the downstream end of the aerosol generating article. The downstream section may include one or more elements, each of which will be described in more detail within the present disclosure.

[0205] Preferably, the downstream section comprises at least one hollow tubular element. The hollow tubular element may be adjacent to the downstream end of the strip of aerosol generating substrate. The hollow tubular element may be arranged immediately downstream of the aerosol generating substrate. In other words, the hollow tubular element may abut the downstream end of the aerosol generating substrate. Such an arrangement may optimize the flow of aerosol from the longitudinal airflow channel of the hollow tubular substrate element into the downstream section and through the aerosol generating article.

[0206] Preferably, the downstream section of the aerosol-generating article comprises a single hollow tubular element. In other words, the downstream section of the aerosol-generating article may comprise only one hollow tubular element.

[0207] The hollow tubular element of the downstream section may also be referred to as hollow tubular downstream element.

[0208] In the case of the present disclosure, the hollow tubular element of the downstream section provides an unrestricted flow channel through the airflow passage. This means that the hollow tubular element provides a negligible level of resistance to draw (RTD) as defined above. Therefore, the airflow passage should be free of any components that hinder the flow of air in the longitudinal direction. Preferably, the airflow passage is substantially empty.

[0209] The hollow tubular element of the downstream section provides a cavity downstream of the aerosol-generating substrate, which can enhance cooling and nucleation of aerosol particles generated by the aerosol-generating substrate.The hollow tubular element of the downstream section can thus serve as an aerosol-cooling element.

[0210] The length of the hollow tubular element may be at least about 12 mm. The length of the hollow tubular element may be at least about 15 mm. The length of the hollow tubular element may be at least about 20 mm.

[0211] The length of the hollow tubular element of the downstream section may be less than or equal to about 50 mm. The length of the hollow tubular element may be less than or equal to about 45 mm. The length of the hollow tubular element may be less than or equal to about 40 mm.

[0212] For example, the length of the hollow tubular element of the downstream section may be between about 12 mm and 50 mm. The length of the hollow tubular element may be between about 15 mm and 45 mm. The length of the hollow tubular element may be between about 20 mm and 40 mm. The length of the hollow tubular element may be about 30 mm.

[0213] A relatively long hollow tubular element is provided within the downstream section of the aerosol-generating article and defines a relatively long internal cavity.Providing a relatively long cavity can maximize the above-mentioned nucleation benefits, thereby improving aerosol formation and cooling.

[0214] The ratio between the length of the hollow tubular matrix element and the length of the hollow tubular element of the downstream section may be less than or equal to about 1.25. Preferably, the ratio between the length of the hollow tubular matrix element and the length of the hollow tubular element of the downstream section may be less than or equal to about 1. More preferably, the ratio between the length of the hollow tubular matrix element and the length of the hollow tubular element of the downstream section may be less than or equal to about 0.75.

[0215] The ratio between the length of the hollow tubular matrix element and the length of the hollow tubular element of the downstream section may be at least about 0.2. Preferably, the ratio between the length of the hollow tubular matrix element and the length of the hollow tubular element of the downstream section may be at least about 0.25. More preferably, the ratio between the length of the hollow tubular matrix element and the length of the hollow tubular element of the downstream section may be at least about 0.3.

[0216] For example, the ratio between the length of the hollow tubular matrix element and the length of the hollow tubular element of the downstream segment may be between about 0.2 and about 1.25, or between about 0.25 and about 1, or between about 0.3 and about 0.75.

[0217] The ratio between the length of the hollow tubular element of the downstream section and the total length of the downstream section may be less than or equal to about 1. Preferably, the ratio between the length of the hollow tubular element of the downstream section and the total length of the downstream section may be less than or equal to about 0.90. More preferably, the ratio between the length of the hollow tubular element of the downstream section and the total length of the downstream section may be less than or equal to about 0.85.

[0218] The ratio between the length of the hollow tubular element of the downstream section and the total length of the downstream section may be at least about 0.35. Preferably, the ratio between the length of the hollow tubular element of the downstream section and the total length of the downstream section may be at least about 0.45. More preferably, the ratio between the length of the hollow tubular element of the downstream section and the total length of the downstream section may be at least about 0.50.

[0219] For example, the ratio between the length of the hollow tubular element of the downstream section and the total length of the downstream section may be between about 0.35 and about 1, or between about 0.45 and about 0.9, or between about 0.5 and about 0.85.

[0220] The ratio between the length of the hollow tubular element of the downstream section and the total length of the aerosol-generating article may be less than or equal to about 0.80. Preferably, the ratio between the length of the hollow tubular element of the downstream section and the total length of the aerosol-generating article may be less than or equal to about 0.70. More preferably, the ratio between the length of the hollow tubular element of the downstream section and the total length of the aerosol-generating article may be less than or equal to about 0.60.

[0221] The ratio between the length of the hollow tubular element of the downstream section and the total length of the aerosol-generating article may be at least about 0.25. Preferably, the ratio between the length of the hollow tubular element of the downstream section and the total length of the aerosol-generating article may be at least about 0.30. More preferably, the ratio between the length of the hollow tubular element of the downstream section and the total length of the aerosol-generating article may be at least about 0.40.

[0222] For example, the ratio between the length of the hollow tubular element of the downstream section and the total length of the aerosol-generating article may be between about 0.25 and about 0.8, or between about 0.3 and about 0.7, or between about 0.4 and about 0.6.

[0223] The wall thickness of the hollow tubular element of the downstream section may be at least about 100 microns. The wall thickness of the hollow tubular element of the downstream section may be at least about 150 microns. The wall thickness of the hollow tubular element of the downstream section may be at least about 200 microns, preferably at least about 250 microns and even more preferably at least about 500 microns (or 0.5 mm).

[0224] The wall thickness of the hollow tubular element of the downstream section may be less than or equal to about 2 mm, preferably less than or equal to about 1.5 mm and even more preferably less than or equal to about 1.25 mm. The wall thickness of the hollow tubular element of the downstream section may be less than or equal to about 1 mm. The wall thickness of the hollow tubular element of the downstream section may be less than or equal to about 500 microns.

[0225] The wall thickness of the hollow tubular element of the downstream section may be between about 100 micrometers and about 2 millimeters, preferably between about 150 micrometers and about 1.5 millimeters, even more preferably between about 200 micrometers and about 1.25 millimeters.

[0226] Keeping the wall thickness of the hollow tubular segment of the downstream section relatively low ensures that the overall internal volume of the hollow tubular element (once the aerosol components leave the aerosol generating substrate, making it available for the aerosol to begin the nucleation process) and the cross-sectional surface area of ​​the cavity of the hollow tubular element are effectively maximized, while ensuring that the hollow tubular element has the necessary structural strength to prevent the collapse of the aerosol generating article and provide some support for the strip of the aerosol generating substrate, and the RTD of the hollow tubular element is minimized. Larger values ​​of the cross-sectional surface area of ​​the cavity of the hollow tubular element should be understood to be associated with a reduced velocity of the aerosol flow traveling along the aerosol generating article, which is also expected to be beneficial to aerosol nucleation. In addition, it appears that by utilizing a hollow tubular element with a relatively low thickness, ventilation air diffusion can be substantially prevented before the ventilation air contacts and mixes with the aerosol flow, which is also understood to be further beneficial to the nucleation phenomenon. In fact, by providing more controllable local cooling of the volatile substance flow, it is possible to enhance the effect of cooling on the formation of new aerosol particles.

[0227] Preferably, the outer diameter of the hollow tubular element of the downstream section is approximately equal to the outer diameter of the aerosol-generating substrate and the outer diameter of the aerosol-generating article.The hollow tubular element of the downstream section preferably has an outer diameter greater than the outer diameter of the hollow tubular substrate element of the aerosol-generating substrate.

[0228] The hollow tubular element may have an outer diameter between 5 and 10 mm, for example between 5.5 and 9 mm or between 6 and 8 mm.

[0229] The hollow tubular element of the downstream section may have a constant inner diameter along the length of the hollow tubular element.However, the inner diameter of the hollow tubular element may vary along the length of the hollow tubular element.

[0230] The hollow tubular element of the downstream section may have an inner diameter of at least about 2 mm. For example, the hollow tubular element may have an inner diameter of at least about 2.5 mm, at least about 3 mm, or at least about 3.5 mm. Providing a hollow tubular element with an inner diameter as described above can advantageously provide the hollow tubular element with sufficient rigidity and strength.

[0231] The hollow tubular element of the downstream section may have an inner diameter of no more than about 10 mm. For example, the hollow tubular element may have an inner diameter of no more than about 9 mm, no more than about 8 mm, or no more than about 7.5 mm. Providing a hollow tubular element having an inner diameter as described above can advantageously reduce the suction resistance of the hollow tubular segment.

[0232] For example, the hollow tubular element of the downstream section may have an inner diameter between about 2 mm and about 10 mm, between about 2.5 mm and about 9 mm, between about 3 mm and about 8 mm, or between about 3.5 mm and about 7.5 mm.

[0233] The ratio of the inner diameter of the hollow tubular matrix element to the inner diameter of the hollow tubular element of the downstream section is preferably between about 0.8 and about 1.2, more preferably between about 0.9 and about 1.1, and most preferably about 1.

[0234] Particularly preferably, the inner diameter of the hollow tubular matrix element is substantially equal to the inner diameter of the hollow tubular element of the downstream section.

[0235] The central longitudinal axis of the hollow tubular matrix element of the aerosol-generating substrate may preferably be aligned with the central longitudinal axis of the hollow tubular element of the downstream segment. For example, in the case where the inner diameter of the hollow tubular matrix element is substantially equal to the inner diameter of the hollow tubular element of the downstream segment, the central longitudinal axis of the hollow tubular matrix element may be aligned with the central longitudinal axis of the hollow tubular matrix element of the downstream segment, such that the lumen of the hollow tubular matrix element and the lumen of the hollow tubular element of the downstream segment may be substantially aligned.

[0236] The hollow tubular element of the downstream section may comprise a paper-based material. The hollow tubular element may comprise at least one paper layer. The paper may be a very rigid paper. The paper may be a curled paper, such as a curled heat-resistant paper or a curled parchment paper.

[0237] Preferably, the hollow tubular element may comprise cardboard. The hollow tubular element may be a cardboard tube. The hollow tubular element may be formed from cardboard. Advantageously, cardboard is a cost-effective material that provides a balance between being deformable so as to provide ease of insertion of the aerosol-generating article into the aerosol-generating device and being sufficiently rigid to provide appropriate engagement of the article with the interior of the device. Thus, the cardboard tube may provide suitable resistance to deformation or compression during use.

[0238] The hollow tubular element of the downstream section can be a paper tube. The hollow tubular element can be a tube formed by spirally winding paper. The hollow tubular element can be formed from multiple paper layers. The paper can have a basis weight of at least about 50 grams per square meter, at least about 60 grams per square meter, at least about 70 grams per square meter, or at least about 90 grams per square meter.

[0239] The hollow tubular element of the downstream section may include a polymer material. For example, the hollow tubular element may include a polymer film. The polymer film may include a cellulose film. The hollow tubular segment may include low density polyethylene (LDPE) or polyhydroxyalkanoate (PHA) fibers. The hollow tubular element may include cellulose acetate tow.

[0240] Where the hollow tubular element comprises cellulose acetate tow, the cellulose acetate tow may have a denier per filament of between about 2 and about 4 and a total denier of between about 25 and about 40.

[0241] The hollow tubular element may be at the upstream end of the downstream section.The hollow tubular element may abut the downstream end of the aerosol-generating substrate.The hollow tubular element may abut the downstream end of the hollow tubular substrate element.

[0242] Aerosol-generating articles according to the present disclosure may comprise a ventilation zone at a location along the downstream section. In more detail, where the downstream section comprises a hollow tubular element, the ventilation zone may be provided at a location along the hollow tubular element.

[0243] Thus, the ventilation cavity is arranged downstream of the strip of aerosol-generating substrate. This may provide a particularly efficient cooling of the aerosol and promote enhanced nucleation of aerosol particles.

[0244] The ventilation zone may typically comprise a plurality of perforations through the circumferential wall of the hollow tubular element. The plurality of perforations of the ventilation zone may also pass through any packaging defining the hollow tubular element. Preferably, the ventilation zone comprises at least one row of circumferential perforations. The ventilation zone may comprise two rows of circumferential perforations. For example, the perforations may be formed on a production line during manufacture of the aerosol-generating article. Preferably, each row of circumferential perforations comprises 8 to 30 perforations.

[0245] The downstream section may further comprise a mouthpiece element. The mouthpiece element may be located at the downstream end of the aerosol-generating article. Preferably, the mouthpiece element is located downstream of the hollow tubular element of the downstream section, which is described above. The mouthpiece element may extend between the hollow tubular element of the downstream section and the downstream end of the aerosol-generating article.

[0246] Providing a mouthpiece element at the downstream end of an aerosol-generating article according to the present disclosure may provide an appealing appearance and mouthfeel to consumers.

[0247] The mouthpiece element may be a mouthpiece filter element. The mouthpiece element may include at least one mouthpiece filter segment formed of a fibrous filter material. Parameters or characteristics described with respect to the mouthpiece element as a whole may also apply to the mouthpiece filter segment of the mouthpiece element.

[0248] The fibrous filter material may be used to filter the aerosol generated by the aerosol generating substrate. Suitable fibrous filter materials will be known to the skilled person. Particularly preferably, at least one mouthpiece filter segment comprises a cellulose acetate filter segment formed from cellulose acetate tow.

[0249] The mouthpiece element may be comprised of a single mouthpiece filter segment.The mouthpiece element may comprise two or more mouthpiece filter segments axially aligned with each other in an abutting end-to-end relationship.

[0250] The downstream section may include a mouth-end cavity at the downstream end downstream of the mouthpiece element as described above. The mouth-end cavity may be defined by a further hollow tubular element disposed at the downstream end of the mouthpiece element. The mouth-end cavity may be defined by an outer wrapper of the aerosol-generating article, wherein the outer wrapper extends from (or through) the mouthpiece element in the downstream direction. For example, the mouth-end cavity may be defined by a tipping wrapper extending downstream through the mouthpiece element.

[0251] The mouthpiece element may optionally include a flavoring agent, which may be provided in any suitable form. For example, the mouthpiece element may include one or more capsules, beads or particles of a flavoring agent, or one or more threads or filaments loaded with a flavoring agent.

[0252] Preferably, the mouthpiece element or mouthpiece filter segment thereof has a low particle filtration efficiency.

[0253] Preferably, the mouthend element is defined by a rod wrap.Preferably, the mouthend element is non-ventilated, such that air does not enter the aerosol-generating article along the mouthend element.

[0254] Preferably, the mouthpiece element has an outer diameter approximately equal to the outer diameter of the aerosol generating article. The diameter of the mouthpiece element (or mouthpiece filter segment) may be substantially the same as the outer diameter of the hollow tubular element. As mentioned in the present disclosure, the outer diameter of the hollow tubular element may be about 7.2 mm ± 10%.

[0255] The diameter of the mouthpiece element may be between about 5 mm and about 10 mm. The diameter of the mouthpiece element may be between about 5.5 mm and about 9 mm. The diameter of the mouthpiece element may be between about 6 mm and about 8 mm. The diameter of the mouthpiece element may be about 7.2 mm ± 10%. The diameter of the mouthpiece element may be about 7.25 mm ± 10%.

[0256] Unless otherwise stated, the resistance to draw (RTD) of a component or aerosol-generating article is measured according to ISO 6565-2015. RTD refers to the pressure required to force air through the full length of the component. The terms "pressure drop" or "resistance to draw" of a component or article may also refer to "resistance to draw".

[0257] The resistance to draw (RTD) of the downstream section may be at least about 0 mm H2O. The RTD of the downstream section may be at least about 3 mm H2O. The RTD of the downstream section may be at least about 6 mm H2O.

[0258] The RTD of the downstream section may be no greater than about 12 mm H2O. The RTD of the downstream section may be no greater than about 11 mm H2O. The RTD of the downstream section may be no greater than about 10 mm H2O.

[0259] The suction resistance of the downstream section may be greater than or equal to about 0 mm H2O and less than about 12 mm H2O. Preferably, the suction resistance of the downstream section may be greater than or equal to about 3 mm H2O and less than about 12 mm H2O. The suction resistance of the downstream section may be greater than or equal to about 0 mm H2O and less than about 11 mm H2O. Even more preferably, the suction resistance of the downstream section may be greater than or equal to about 3 mm H2O and less than about 11 mm H2O. Even more preferably, the suction resistance of the downstream section may be greater than or equal to about 6 mm H2O and less than about 10 mm H2O. Preferably, the suction resistance of the downstream section may be about 8 mm H2O.

[0260] The resistance to draw (RTD) characteristics of the downstream section may be entirely or primarily attributable to the RTD characteristics of the mouthpiece element of the downstream section. In other words, the RTD of the mouthpiece element of the downstream section may entirely define the RTD of the downstream section.

[0261] The resistance to draw (RTD) of the mouthpiece element may be at least about 0 mm H2O. The RTD of the mouthpiece element may be at least about 3 mm H2O. The RTD of the mouthpiece element may be at least about 6 mm H2O.

[0262] The RTD of the mouthpiece element may be no greater than about 12 mm H2O. The RTD of the mouthpiece element may be no greater than about 11 mm H2O. The RTD of the mouthpiece element may be no greater than about 10 mm H2O.

[0263] The draw resistance of the mouthpiece element may be greater than or equal to about 0 mm H2O and less than about 12 mm H2O. Preferably, the draw resistance of the mouthpiece element may be greater than or equal to about 3 mm H2O and less than about 12 mm H2O. The draw resistance of the mouthpiece element may be greater than or equal to about 0 mm H2O and less than about 11 mm H2O. Even more preferably, the draw resistance of the mouthpiece element may be greater than or equal to about 3 mm H2O and less than about 11 mm H2O. Even more preferably, the draw resistance of the mouthpiece element may be greater than or equal to about 6 mm H2O and less than about 10 mm H2O. Preferably, the draw resistance of the mouthpiece element may be about 8 mm H2O.

[0264] As described above, the mouthpiece element or the mouthpiece filter segment may be formed of a fibrous material. The mouthpiece element may be formed of a porous material. The mouthpiece element may be formed of a biodegradable material. The mouthpiece element may be formed of a cellulose material such as cellulose acetate. For example, the mouthpiece element may be formed of bundled cellulose acetate fibers having a single filament denier between about 10 and about 15. For example, the mouthpiece element is formed of a relatively low density cellulose acetate tow, such as a cellulose acetate tow comprising fibers having a single filament denier of about 12.

[0265] The mouthpiece element may be formed of a polylactic acid based material. The mouthpiece element may be formed of a bioplastic material, preferably a starch based bioplastic material. The mouthpiece element may be made by injection molding or by extrusion. Bioplastic based materials are advantageous because they can provide a mouthpiece element structure that is simple and inexpensive to manufacture, has a specific and complex cross-sectional profile, and the mouthpiece element structure may include a plurality of relatively large airflow channels extending through the mouthpiece element material, which provides suitable RTD characteristics.

[0266] The mouthpiece element may be formed from a sheet of suitable material that has been curled, pleated, gathered, woven or folded into an element defining a plurality of longitudinally extending channels. Such a sheet of suitable material may be formed from paper, paperboard, a polymer (e.g., polylactic acid), or any other cellulose-based, paper-based, or bioplastic-based material. The cross-sectional profile of such a mouthpiece element may show the channels as being randomly oriented.

[0267] The mouthpiece element may be formed in any suitable manner. For example, the mouthpiece element may be formed from a bundle of longitudinally extending tubes. The longitudinally extending tubes may be formed from polylactic acid. The mouthpiece element may be formed by extrusion, molding, lamination, injection or shredding of a suitable material. Therefore, it is preferred that there is a low pressure drop (or RTD) from the upstream end of the mouthpiece element to the downstream end of the mouthpiece element.

[0268] The length of the mouthpiece element may be at least about 1.5 mm. The length of the mouthpiece element may be at least about 2 mm. The length of the mouthpiece element may be equal to or less than about 7 mm. The length of the mouthpiece element may be equal to or less than about 4 mm. For example, the length of the mouthpiece element may be between about 1.5 mm and about 7 mm. The length of the mouthpiece element may be between about 2 mm and about 4 mm.

[0269] The ratio between the length of the mouthpiece element and the length of the downstream section may be less than or equal to about 0.35. Preferably, the ratio between the length of the mouthpiece element and the length of the downstream section may be less than or equal to about 0.30. More preferably, the ratio between the length of the mouthpiece element and the length of the downstream section may be less than or equal to about 0.25.

[0270] The ratio between the length of the mouthpiece element and the length of the downstream section may be at least about 0.03. Preferably, the ratio between the length of the mouthpiece element and the length of the downstream section may be at least about 0.05. More preferably, the ratio between the length of the mouthpiece element and the length of the downstream section may be at least about 0.1.

[0271] For example, the ratio between the length of the mouthend element and the length of the downstream section is from about 0.03 to about 0.35, preferably from about 0.05 to about 0.30, more preferably from about 0.1 to about 0.25.

[0272] The ratio between the length of the mouthpiece element and the total length of the aerosol-generating article may be less than or equal to about 0.20. Preferably, the ratio between the length of the mouthpiece element and the total length of the aerosol-generating article may be less than or equal to about 0.15. More preferably, the ratio between the length of the mouthpiece element and the total length of the aerosol-generating article may be less than or equal to about 0.1.

[0273] The ratio between the length of the mouthpiece element and the total length of the aerosol-generating article may be at least about 0.01. Preferably, the ratio between the length of the mouthpiece element and the total length of the aerosol-generating article may be at least about 0.02. More preferably, the ratio between the length of the mouthpiece element and the total length of the aerosol-generating article may be at least about 0.05.

[0274] For example, the ratio between the length of the mouthend element and the overall length of the aerosol-generating article is from about 0.01 to about 0.2, preferably from about 0.02 to about 0.15, more preferably from about 0.05 to about 0.1.

[0275] In the case where the downstream section includes a hollow tubular element and a mouthpiece element, the ratio of the length of the hollow tubular element to the length of the mouthpiece element may be at least about 1.5. In other words, the length of the hollow tubular element may be at least about 150% of the length of the mouthpiece element. The ratio of the length of the hollow tubular element to the length of the mouthpiece element may be at least about 5. The ratio of the length of the hollow tubular element to the length of the mouthpiece element may be at least about 7.5.

[0276] The ratio of the length of the hollow tubular element to the length of the mouthpiece element may be equal to or less than about 20. The ratio of the length of the hollow tubular element to the length of the mouthpiece element may be equal to or less than about 15. The ratio of the length of the hollow tubular element to the length of the mouthpiece element may be equal to or less than about 12.5.

[0277] For example, the ratio of the length of the hollow tubular element to the length of the mouthpiece element may be between about 1.5 and about 20, or between about 5 and about 15, or between about 7.5 and about 10.

[0278] The total length of the downstream section is preferably at least about 15 mm, more preferably at least about 20 mm, and more preferably at least about 25 mm.

[0279] The total length of the downstream section is preferably less than about 50 mm, more preferably less than about 45 mm, more preferably less than about 40 mm.

[0280] For example, the downstream section may have a total length of between about 20 mm and about 50 mm, more preferably between about 25 mm and about 45 mm, more preferably between about 30 mm and about 40 mm.

[0281] The ratio between the total length of the downstream segment and the total length of the aerosol-generating article may be less than or equal to about 0.80. Preferably, the ratio between the length of the downstream segment and the total length of the aerosol-generating article may be less than or equal to about 0.75. More preferably, the ratio between the length of the downstream segment and the total length of the aerosol-generating article may be less than or equal to about 0.70. Even more preferably, the ratio between the length of the downstream segment and the total length of the aerosol-generating article may be less than or equal to about 0.65.

[0282] The ratio between the length of the downstream segment and the total length of the aerosol-generating article may be at least about 0.30. Preferably, the ratio between the length of the downstream segment and the total length of the aerosol-generating article may be at least about 0.40. More preferably, the ratio between the length of the downstream segment and the total length of the aerosol-generating article may be at least about 0.50. Even more preferably, the ratio between the length of the downstream segment and the total length of the aerosol-generating article may be at least about 0.60.

[0283] Preferably, the total length of the aerosol-generating article according to the present invention is at least about 35 mm. More preferably, the total length of the aerosol-generating article according to the present invention is at least about 40 mm. Even more preferably, the total length of the aerosol-generating article according to the present invention is at least about 45 mm. Even more preferably, the total length of the aerosol-generating article according to the present invention is at least about 50 mm.

[0284] The total length of the aerosol-generating article according to the present invention is preferably less than or equal to 110 mm. More preferably, the total length of the aerosol-generating article according to the present invention is preferably less than or equal to 100 mm. Even more preferably, the total length of the aerosol-generating article according to the present invention is preferably less than or equal to 75 mm. Even more preferably, the total length of the aerosol-generating article according to the present invention is preferably less than or equal to 70 mm.

[0285] For example, the total length of the aerosol-generating article may be between about 35 mm and about 110 mm, or between about 40 mm and about 100 mm, or between about 45 mm and about 75 mm, or between about 50 mm and about 70 mm.

[0286] The aerosol-generating article preferably has an outer diameter of at least about 5 mm. Preferably, the aerosol-generating article has an outer diameter of at least 5.5 mm. More preferably, the aerosol-generating article has an outer diameter of at least 6 mm.

[0287] Preferably, the aerosol-generating article has an outer diameter of less than or equal to about 10 mm. More preferably, the aerosol-generating article has an outer diameter of less than or equal to about 9 mm. Even more preferably, the aerosol-generating article has an outer diameter of less than or equal to about 8 mm.

[0288] For example, the aerosol-generating article may have an outer diameter of between about 5 mm and about 10 mm, or between about 5.5 mm and about 9 mm, or between about 6 mm and about 8 mm.

[0289] The outer diameter of the aerosol-generating article may be substantially constant over the entire length of the article. Alternatively, different parts of the aerosol-generating article may have different outer diameters.

[0290] One or more of the components of the aerosol-generating article may be individually defined by its own packaging.

[0291] Preferably, the aerosol-generating substrate and the downstream section are combined together by a wrapper, such as a tipping wrapper.

[0292] Preferably, components of aerosol-generating articles according to the present disclosure are made of biodegradable materials.

[0293] A non-exhaustive list of non-limiting examples is provided below.Any one or more features of these examples may be combined with any one or more features of another example or embodiment or aspect described herein.

[0294] EX1. An aerosol generating device having a mouth end for receiving an aerosol generating article, the aerosol generating device comprising:

[0295] A heated chamber for receiving the aerosol-generating article at the mouth end of the device.

[0296] EX2. The aerosol generating device according to Example EX1 further includes an airflow guiding element, which is located within the heating chamber and extends longitudinally toward the mouth end of the device, and the airflow guiding element is configured to be inserted into the aerosol generating article when the aerosol generating article is received within the heating chamber.

[0297] EX3. The aerosol-generating device of example EX1 or EX2, further comprising a heating element disposed at or around the periphery of the heating chamber for heating an aerosol-generating article received within the heating chamber.

[0298] EX4. An aerosol-generating device according to example EX2, wherein the airflow directing element is a heating element for heating an aerosol-generating article received within the heating chamber.

[0299] EX5. An aerosol generating device according to example EX2, wherein the airflow directing element is not a heating element.

[0300] EX6. An aerosol generating device according to example EX2, wherein the airflow directing element is or includes a susceptor element configured to generate heat when placed in an oscillating electromagnetic field.

[0301] EX7. An aerosol generating device according to any of the preceding examples, wherein the width or outer diameter of the airflow guiding element varies along its length, wherein the width or outer diameter of a first portion of the airflow guiding element corresponds to the maximum width or outer diameter of the airflow guiding element, and the width or outer diameter of a second portion of the airflow guiding element located upstream of the first portion is smaller than the maximum width or outer diameter of the airflow guiding element.

[0302] EX8. An aerosol generating device according to any one of examples EX2 to EX7, wherein the width or diameter of the airflow directing element varies along its length.

[0303] EX9. An aerosol generating device according to any of examples EX2 to EX8, wherein the airflow directing element extends along at least 25% of the length of the heating chamber.

[0304] EX10. An aerosol generating device according to any of examples EX2 to EX9, wherein the airflow directing element extends along at least 50% of the length of the heating chamber.

[0305] EX11. An aerosol generating device according to any of examples EX2 to EX10, wherein the airflow directing element extends along at least 60% of the length of the heating chamber.

[0306] EX12. An aerosol generating device according to any of examples EX2 to EX11, wherein the airflow directing element comprises a central core portion and an extension portion positioned along the core portion, wherein the extension portion extends outwardly from the core portion.

[0307] EX13. An aerosol generating device according to example EX12, wherein the extension portion is substantially shaped in the form of a hemisphere, a sphere, a cylinder, a cone or a ring.

[0308] EX14. An aerosol generating device according to example EX12 or EX13, wherein the core portion is substantially shaped in the form of a rod, a tube or a cone.

[0309] EX15. An aerosol generating device according to any of examples EX12 to EX14, wherein the airflow directing element comprises at least two extension portions positioned along the core portion.

[0310] EX16. An aerosol generating device according to any of examples EX12 to EX14, wherein the airflow directing element comprises at least two extending portions, each positioned at a different position along the core portion.

[0311] EX17. An aerosol generating device according to any one of examples EX2 to EX16, wherein the airflow directing element comprises a hollow tube.

[0312] EX18. The aerosol generating device of any of Examples EX2 to EX17, further comprising a base support element, and wherein the airflow directing element extends from the base support element.

[0313] EX19. An aerosol generating device according to example EX18, wherein the base support element is located at the upstream end of the heating chamber.

[0314] EX20. An aerosol-generating article according to example EX18 or EX19, wherein the base support element is porous or comprises at least one aperture such that fluid communication is established through the base support element.

[0315] EX21. An aerosol-generating article according to any one of Examples EX2 to EX20, wherein the airflow guiding element comprises an airflow inlet at a first position and an airflow outlet at a second position downstream of the first position, so that the airflow path is defined within and along the airflow guiding element.

[0316] EX22. An aerosol-generating article according to any of examples EX2 to EX21, wherein a maximum width or diameter of the portion of the airflow directing element extending into the heating chamber is at least about 25% of the diameter of the heating chamber.

[0317] EX23. An aerosol-generating article according to any of examples EX2 to EX22, wherein a maximum width or diameter of the portion of the airflow directing element extending into the heating chamber is at least about 50% of the diameter of the heating chamber.

[0318] EX24. An aerosol-generating article according to any of examples EX2 to EX23, wherein a maximum width or diameter of the portion of the airflow directing element extending into the heating chamber is at least about 75% of the diameter of the heating chamber.

[0319] EX25. The aerosol-generating article of any of examples EX2 to EX24, wherein the outer surface of the airflow directing element is textured.

[0320] EX26. An aerosol generating system comprising an aerosol generating device according to any of the preceding examples and an aerosol generating article configured to be received within the heating chamber.

[0321] EX27. An aerosol generating system, comprising an aerosol generating device according to any one of Examples EX2 to EX25 and an aerosol generating article configured to be received in the heating chamber, the aerosol generating article comprising an aerosol generating substrate, wherein the aerosol generating substrate is in the form of a hollow tubular segment, the hollow tubular segment defining a substrate cavity extending from an upstream end of the aerosol generating substrate to a downstream end of the aerosol generating substrate, wherein when the aerosol generating article is received in the heating chamber of the device, the airflow guiding element extends longitudinally into the substrate cavity.

[0322] EX28. An aerosol generating system according to example EX27, wherein the width or diameter of the airflow directing element is smaller than the diameter of the substrate cavity.

[0323] EX29. An aerosol-generating system according to example EX27 or EX28, wherein the aerosol-generating article further comprises an upstream section located upstream of the aerosol-generating substrate, wherein the upstream section comprises an upstream element adjacent to the upstream end of the aerosol-generating substrate.

[0324] EX30. An aerosol-generating system according to any of Examples EX27 to EX29, wherein a portion of the airflow-directing element contacts a portion of the aerosol-generating substrate.

[0325] EX31. An aerosol generating system according to any of Examples EX27 to EX30, wherein a width or diameter of a portion of the airflow directing element substantially corresponds to a diameter of the substrate cavity.

[0326] EX32. An aerosol generating system according to any of examples EX27 to EX31, wherein an outer longitudinal surface of the airflow directing element and an inner longitudinal surface of the aerosol generating substrate define an airflow channel.

[0327] EX33. An aerosol generating system according to Example EX29, wherein the upstream element comprises a solid rod segment.

[0328] EX34. An aerosol generating system according to Example EX29, wherein the upstream element comprises a hollow tubular segment.

[0329] EX35. The aerosol-generating system of any of Examples EX27 to EX34, further comprising a downstream section located downstream from the aerosol-generating substrate, the downstream section comprising one or more of a mouthpiece element and a hollow tubular element.

[0330] EX36. An aerosol-generating article according to example EX27, wherein the mouthpiece element comprises at least one mouthpiece filter segment formed of a fibrous filter material.

[0331] EX37. An aerosol generating system according to any one of Examples EX27 to EX36, wherein the aerosol generating substrate has a length between 5 mm and 30 mm.

[0332] EX38. An aerosol generating system according to any one of Examples EX27 to EX36, wherein the aerosol generating substrate has a length between 5 mm and 16 mm.

[0333] EX39. An aerosol-generating system according to any of Examples EX27 to EX38, wherein the wall thickness of the aerosol-generating substrate is between 5% and 40% of the outer diameter of the aerosol-generating substrate.

[0334] EX40. An aerosol-generating system according to any one of examples EX27 to EX39, wherein the wall thickness of the aerosol-generating substrate is at least 200 microns.

[0335] EX41. An aerosol-generating system according to any of Examples EX27 to EX40, wherein the aerosol-generating substrate comprises homogenized tobacco material.

[0336] EX42. An aerosol-generating system according to any of examples EX27 to EX41, wherein the aerosol-generating substrate is formed from a plurality of overlapping sheets of homogenised tobacco material.

[0337] EX43. An aerosol generating system according to any one of Examples EX27 to EX42, wherein the aerosol generating substrate comprises one or more aerosol formers, and wherein the content of the aerosol former in the aerosol generating substrate is between 10 wt % and 20 wt % on a dry weight basis.

[0338] EX44. An aerosol generating system according to any of examples EX27 to EX43, wherein a portion of the airflow directing element is coated with one or more of a further aerosol generating substrate, a flavoring agent, and an aerosol former.

[0339] EX45. An aerosol generating system according to example EX43 or EX44, wherein the aerosol former comprises one or more of glycerol and propylene glycol.

[0340] EX46. An aerosol generating system according to any of examples EX27 to EX45, wherein the airflow directing element extends along at least 25% of the length of the substrate cavity.

[0341] EX47. An aerosol generating system according to any of examples EX27 to EX45, wherein the airflow directing element extends along at least 50% of the length of the substrate cavity.

[0342] EX48. An aerosol generating system according to any of examples EX27 to EX45, wherein the airflow directing element extends along at least 60% of the length of the substrate cavity.

[0343] EX49. The aerosol generating system of any of examples EX27 to EX48, wherein a maximum width or diameter of the portion of the airflow directing element extending into the substrate cavity is at least about 25% of the diameter of the substrate cavity.

[0344] EX50. The aerosol generating system of any of examples EX27 to EX48, wherein a maximum width or diameter of the portion of the airflow directing element extending into the substrate cavity is at least about 50% of the diameter of the substrate cavity.

[0345] EX51. The aerosol generating system of any of examples EX27 to EX48, wherein a maximum width or diameter of the portion of the airflow directing element extending into the substrate cavity is at least about 75% of the diameter of the substrate cavity. BRIEF DESCRIPTION OF THE DRAWINGS

[0346] The present invention will be further described, by way of example only, with reference to the accompanying drawings, in which:

[0347] Figure 1 shows a schematic side cross-sectional view of an aerosol generating device according to an embodiment of the present invention;

[0348] Figure 2 shows a schematic side cross-sectional view of an aerosol generating device according to an embodiment of the present invention;

[0349] Figure 3 shows a schematic side cross-sectional view of an aerosol generating device according to an embodiment of the present invention;

[0350] Figure 4 shows a schematic side cross-sectional view of an aerosol generating device according to an embodiment of the present invention;

[0351] Figure 5 shows a schematic side cross-sectional view of an aerosol generating article for an aerosol generating device according to an embodiment of the present invention;

[0352] Figure 6 shows a schematic side cross-sectional view of an aerosol generating article for an aerosol generating device according to an embodiment of the present invention;

[0353] Figure 7 shows a schematic side cross-sectional view of an aerosol generating system including an aerosol generating article and an aerosol generating device according to an embodiment of the invention;

[0354] Figure 8 shows a schematic side cross-sectional view of an aerosol generating system including an aerosol generating article and an aerosol generating device according to an embodiment of the invention;

[0355] Fig. 9 a schematic side cross-sectional view showing an aerosol generating device according to an embodiment of the invention; and

[0356] Fig.10 shows a schematic side cross-sectional view of an aerosol generating system including an aerosol generating article and an aerosol generating device according to an embodiment of the invention; DETAILED DESCRIPTION

[0357] Figure 1 The mouth end portion of the aerosol generating device 100 is shown, which is configured to receive and heat a corresponding aerosol generating article. In particular, Figure 1 The downstream mouth end portion of the aerosol generating device 100 is shown where a device cavity (or heating chamber) 108 of the device is defined and may receive an aerosol generating article. A compatible aerosol generating article may include a hollow open distal end and a hollow aerosol generating element.

[0358] The aerosol generating device 100 comprises a housing (or body) 104 extending between a mouth end 102 and a distal end (not shown). The housing 104 comprises a peripheral wall 106. The peripheral wall 106 defines a device cavity or heating chamber 108 for receiving an aerosol generating article. The device cavity 108 is defined by a closed distal end 103 and an open mouth end 102. The mouth end of the device cavity 108 is located at the mouth end 102 of the aerosol generating device 100. The aerosol generating article is configured to be received through the mouth end of the device cavity 108 and to be held within the device cavity 108.

[0359] The aerosol generating device 100 further comprises a heater 110 and a power source (not shown) for supplying power to the heater 110. A controller (not shown) is also provided to control such power supply to the heater. The heater 110 is configured to controllably heat the aerosol generating article during use when the aerosol generating article is received within the device 100. In the present embodiment, the heater 110 is arranged to externally heat the aerosol generating substrate 12 of the aerosol generating article during use.

[0360] The aerosol generating device 100 further comprises an airflow directing element 20 extending from the closed distal end 103 along the device cavity 108. The airflow directing element 20 extends along a central longitudinal axis of the device cavity 108. The airflow directing element 20 has a fixed upstream end and a free downstream end.

[0361] The airflow direction element 20 includes an irregular outer surface such that the outer diameter of the airflow direction element 20 varies along its length.

[0362] The airflow directing element 202 includes a core elongated portion 21 and a plurality of extension portions 23, 27 extending radially outward from the core elongated portion 21. The airflow directing element 202 includes three extension portions 23, 27. The first extension portion 27 is located at the upstream fixed end of the airflow directing element 20 and is hemispherical. The upstream end of the first extension portion 27 is flat and is coupled to the distal end 104 of the device cavity 108. Figure 1 , downstream of the first extension 231 are two sequentially arranged spherical extensions 23. One of the extensions 23 is located at the downstream free end of the airflow guide element 20, and the other is located a short distance upstream thereof, between the extension 27 and the other extension 23.

[0363] The air flow guiding element 20 is made of or comprises cardboard.

[0364] The length of the airflow directing element 20 is about 8 mm. The maximum outer diameter or width of the airflow directing element 20 is about 3 mm. The minimum outer diameter or width of the airflow directing element 20 is about 1 mm. The diameter of the device cavity 108 is between about 7.25 mm and about 7.3 mm. The length of the device cavity 108 is at least about 15 mm.

[0365] Figure 2 An aerosol generating device 200 is shown, which is different from Figure 1The aerosol generating device 100 shown in the figure has a different structure in that the airflow directing element 201 includes a base support element 25 and a longer device cavity 208. The airflow directing element 201 includes an irregular outer surface so that the outer diameter of the airflow directing element 201 varies along its length. The airflow directing element 201 includes a core elongated portion 21 and a plurality of extensions 23 extending radially outward from the core elongated portion 21. The airflow directing element 201 includes three extensions 23, the first extension being positioned at the downstream free end of the airflow directing element 201, the second extension being positioned not far upstream of the first extension 23, and the third extension being positioned at the upstream fixed end of the airflow directing element 201. The extensions 23 are spherical. The airflow directing element 201 is made of or includes cardboard.

[0366] The aerosol generating device 200 comprises a base support element 25 coupled to the distal closed end of the device cavity 103. The airflow directing element 201 is coupled to the downstream end of the base support element 25 and extends downstream therefrom. The base support element 25 comprises a porous material or one or more holes (not shown) extending through its length to allow air to flow therethrough when the aerosol generating article is received within the device cavity 208. The length of the base support element 25 is about 3 mm. In other words, the base support element 25 protrudes about 3 mm from the closed end 103 of the device cavity 208.

[0367] The periphery 26 of the base support element 25 is chamfered to facilitate engagement with the hollow upstream end of the aerosol-generating article when the aerosol-generating article is inserted into the device cavity 208. The chamfered periphery 26 of the base support element 25 acts as a centering guide for insertion of the article into the aerosol-generating device 200, thereby ensuring that the inserted article is centered on the central longitudinal axis of the device cavity 208. The maximum outer diameter or width of the base support element 25 preferably matches the inner diameter of the hollow upstream section of the aerosol-generating article.

[0368] The length of the airflow directing element 201 is about 10 mm. The maximum outer diameter or width of the airflow directing element 201 is about 3 mm. The minimum outer diameter or width of the airflow directing element 201 is about 1 mm. The diameter of the device cavity 208 is between about 7.25 mm and about 7.3 mm. The length of the device cavity 208 is at least about 20 mm.

[0369] Figure 3 An aerosol generating device 300 is shown, which is different from Figure 1The aerosol generating device 100 shown in FIG. 1 has a different structure in that the airflow directing element 202 has a different structure. The airflow directing element 202 comprises an elongated body in the form of a hollow tube having a uniform outer diameter and a closed downstream end. The length of the airflow directing element 202 is about 10 mm. The outer diameter of the airflow directing element 202 is about 3 mm. The airflow directing element 202 is made of or includes cardboard.

[0370] Figure 4 An aerosol generating device 400 is shown, which is different from Figure 1 The aerosol generating device 100 shown in FIG. 1 has a different structure of the airflow directing element 203. The airflow directing element 203 includes an irregular outer surface so that the outer diameter of the airflow directing element 203 varies along its length. The airflow directing element 203 includes a core portion 213 and a plurality of extension portions 233 extending radially outward from the core portion 213. The airflow directing element 203 includes four extension portions 234. The four extension portions 234 are cylindrical protrusions evenly spaced along the core portion 213. In this embodiment, the most upstream and downstream extension portions 234 are spaced from the upstream end and the downstream end of the airflow directing element 203, respectively.

[0371] The air flow guiding element 203 is made of or comprises cardboard.

[0372] The length of the airflow directing element 203 is about 8 mm. The maximum outer diameter or width of the airflow directing element 203 is about 3 mm. The minimum outer diameter or width of the airflow directing element 203 is about 1 mm.

[0373] Figure 5 The aerosol-generating article 1 shown in the accompanying drawings comprises a strip 12 of an aerosol-generating substrate and a downstream section 14 disposed downstream of the strip 12 of the aerosol-generating substrate. The aerosol-generating article 1 extends from an upstream end or distal end 16 coinciding with the upstream end of the aerosol-generating substrate 12 to a downstream end or mouth end 18 coinciding with the downstream end of the downstream section 14. The downstream section 14 may include one or more of a hollow tubular element or a mouthpiece element (not shown), as described within the present disclosure.

[0374] The aerosol-generating article 1 has an outer diameter of approximately 7.25 mm.

[0375] The aerosol-generating substrate 12 comprises a hollow tubular substrate element 40 formed from homogenized tobacco material. The hollow tubular substrate element 40 has a peripheral wall 42 defining a longitudinal cavity 44 that provides an unrestricted flow passage through the hollow tubular substrate element 40. The upstream end of the longitudinal cavity 44 provides an air inlet through which air can be drawn into the aerosol-generating article 10 during use. The hollow tubular substrate element 40 has a length of about 12 millimeters and an outer diameter of about 7.25 mm. The wall thickness of the hollow tubular substrate element 40 is about 1 mm and the diameter of the substrate cavity 44 is 5.25 mm.

[0376] Each component of the aerosol-generating article shown in the figures and described in the present disclosure may be defined by a corresponding wrapper or may be joined together by one or more wrappers not shown in the figures.

[0377] Figure 6 An aerosol generating article 2 is shown which differs from the aerosol generating article 1 in that it also comprises an upstream section 30 arranged upstream of the aerosol generating substrate 12. The upstream section 30 comprises an upstream element 34 in the form of a hollow tubular element which defines an empty longitudinal cavity extending along its entire length. The downstream end of the upstream element 34 abuts the upstream end of the aerosol generating substrate 12. The upstream end 16 is defined by the upstream end of the upstream element 34. The length of the hollow upstream element 34 is about 5 mm. The outer diameter and the inner diameter of the upstream element 34 correspond to the outer diameter and the inner diameter of the aerosol generating element 12 located immediately downstream.

[0378] Figure 7 An exemplary aerosol generating system 10 is shown, comprising an aerosol generating device 100 and an aerosol generating article 1 received within a device cavity (or heating chamber) 108 of the aerosol generating device 100. When the aerosol generating article 1 is inserted into the device cavity 108, the airflow directing element 20 is received within the substrate cavity 44 of the article 1, and the aerosol generating substrate 12 of the article 1 effectively surrounds the airflow directing element 20. The aerosol generating device 100 is configured such that during use, air is configured to enter the device cavity 108 and into the aerosol generating article via its upstream end when puffing is drawn on its downstream end.

[0379] An annular airflow channel 22 is defined between the inner surface of the aerosol-generating substrate 12 and the outer surface of the airflow directing element 20. When a user draws on the mouth end 18 of the aerosol-generating article 1, air can be drawn into the device 100 and around the article 1 toward the distal closed end 103 of the device cavity 108, where the air can reverse its direction and enter the article 1 via its upstream end. The air can then flow through the annular airflow channel 22 and proceed toward the downstream end 18 of the article 1.

[0380] The maximum thickness of the airflow channel 22 is about 1.13 mm and the minimum thickness of the airflow channel 22 is about 2.13 mm.

[0381] Figure 8 An exemplary aerosol generating system 101 is shown, which includes an aerosol generating device 200 and an aerosol generating article 2 received within a device cavity (or heating chamber) 208 of the aerosol generating device 200. When the aerosol generating article 2 is inserted into the device cavity 208, the airflow directing element 201 is received within the substrate cavity 44 of the article 2, and the hollow aerosol generating substrate 12 of the article 2 effectively surrounds the airflow directing element 201. The hollow upstream end of the article 2 is engaged with the base support element 25. The aerosol generating device 200 is configured so that during use, air is configured to enter the device cavity 208 and into the aerosol generating article via its upstream end when suction is drawn on its downstream end.

[0382] The annular airflow channel 22 is defined between the inner surface of the aerosol-generating substrate 12 and the outer surface of the airflow directing element 201. When a user draws on the mouth end 18 of the aerosol-generating article 2, air can be drawn into the device 200 and around the article 2 toward the distal closed end 103 of the device cavity 108, where the air can reverse its direction and enter the article 2 via its upstream end through the base support element 25. The air can then flow through the annular airflow channel 22 and proceed toward the downstream end 18 of the article 1.

[0383] The maximum thickness of the airflow channel 22 is about 1.13 mm and the minimum thickness of the airflow channel 22 is about 2.13 mm.

[0384] Fig. 9 An aerosol generating device 500 is shown, which is different from Figure 1 The aerosol generating device 100 shown in FIG. 1 has a different structure in that the airflow directing element 204 has a different structure. The airflow directing element 204 comprises an elongated body in the form of a hollow tube having a uniform outer diameter and an open downstream end. The length of the airflow directing element 204 is about 10 mm. The outer diameter of the airflow directing element 20 is about 3 mm. The airflow directing element 204 is made of or includes cardboard. The inner diameter of the airflow directing element 204 is about 1.5 mm.

[0385] Fig.10An exemplary aerosol generating system 102 is shown, which includes an aerosol generating device 500 and an aerosol generating article 1 received within a device cavity (or heating chamber) 108 of the aerosol generating device 500. When the aerosol generating article 1 is inserted into the device cavity 108, the airflow directing element 204 is received within the substrate cavity 44 of the article 1, and the hollow aerosol generating substrate 12 of the article 1 effectively surrounds the airflow directing element 201. The hollow upstream end of the article 1 is engaged with the base support element 25. Similarly, an annular airflow channel 22 is defined between the inner surface of the hollow aerosol generating substrate 12 and the outer surface of the airflow directing element 204. When a user draws on the mouth end 18 of the aerosol generating article 1, air can be drawn into the device 200 and around the article 1 toward the distal closed end 103 of the device cavity 108, where the air can reverse its direction and enter the article 2 via its upstream end. The air can then flow through the annular airflow passage 22 and proceed toward the downstream end 18 of the article 1. In addition to the air flowing around the airflow directing element 204 along the annular airflow passage 22, the air can flow into the interior of the hollow tube of the airflow directing element 204 through a porous portion (not shown) present at the base of the airflow directing element 204. The internal longitudinal cavity defined by the airflow directing element 204 defines a secondary airflow passage 24 that extends from the upstream end of the airflow directing element 204 and exits via the open downstream end of the airflow directing element 204.

[0386] The thickness of the airflow channel 22 is about 2.13 mm. The inner diameter of the airflow directing element 204 as shown defines the diameter or width of the secondary airflow channel 24.

[0387] In all figures of the present disclosure, air flow paths, aerosol flow paths, or other fluid paths into and through aerosol-generating articles and devices during use are depicted with discontinuous arrows.

[0388] For the purpose of this specification and the appended claims, unless otherwise indicated, all numbers representing amount, quantity, percentage, etc. should be understood to be modified by the term "about" in all cases. Moreover, all ranges include the disclosed maximum and minimum points, and include any intermediate ranges therein that may be specifically listed or may not be listed in this article. Therefore, in this article, the number A is understood to be ± 10% of A. In this article, the number A may be considered to be included in the numerical value within the general standard error of the measurement of the property modified by the number A. In some cases used in the appended claims, the number A may deviate from the percentage listed above, provided that the amount of A deviation will not substantially affect the basic characteristics and novel features of the invention claimed for protection. Moreover, all ranges include the disclosed maximum and minimum points, and include any intermediate ranges therein that may be specifically listed or may not be listed in this article.

[0389] The specific embodiments and examples described above illustrate but do not limit the present invention. It should be understood that other embodiments of the present invention can be made, and the specific embodiments and examples described herein are not exhaustive.

Claims

1. An aerosol generating system comprising an aerosol generating device having a mouth end for receiving an aerosol generating article and an aerosol generating article for generating an inhalable aerosol when heated, wherein the aerosol generating device comprises: a heating chamber for receiving and heating the aerosol-generating article; as well as an airflow directing element located within the heating chamber and extending longitudinally toward the mouth end of the device, the airflow directing element being configured to be inserted into the aerosol-generating article when the aerosol-generating article is received within the heating chamber, wherein the width or outer diameter of the airflow direction element varies along its length, wherein a first portion of the airflow direction element has a width or outer diameter corresponding to a maximum width or outer diameter of the airflow direction element, and a second portion of the airflow direction element located upstream of the first portion has a width or outer diameter that is smaller than the maximum width or outer diameter of the airflow direction element; and The aerosol generating article comprises an aerosol generating substrate, wherein the aerosol generating substrate is in the form of a hollow tubular segment, the hollow tubular segment defines a substrate cavity extending from an upstream end of the aerosol generating substrate to a downstream end of the aerosol generating substrate, wherein when the aerosol generating article is received in the heating chamber of the device, the airflow guiding element extends longitudinally into the substrate cavity, wherein the airflow channel is defined between an outer surface of the airflow guiding element and an inner surface of the aerosol generating substrate.

2. An aerosol generating system according to claim 1, wherein the aerosol generating device further comprises a heating element for heating an aerosol generating article received in the heating chamber.

3. An aerosol generating system according to claim 2, wherein the heating element is arranged at or around the periphery of the heating chamber.

4. An aerosol generating system comprising an aerosol generating device having a mouth end for receiving an aerosol generating article and an aerosol generating article for generating an inhalable aerosol when heated, wherein the aerosol generating device comprises: a heating chamber for receiving an aerosol-generating article at a mouth end of the device; a heating element disposed at or around a periphery of the heating chamber for heating an aerosol-generating article received within the heating chamber; as well as an airflow directing element located within the heating chamber and extending longitudinally toward the mouth end of the device, the airflow directing element being configured to be inserted into the aerosol-generating article when the aerosol-generating article is received within the heating chamber; and The aerosol generating article comprises an aerosol generating substrate, wherein the aerosol generating substrate is in the form of a hollow tubular segment, the hollow tubular segment defines a substrate cavity extending from an upstream end of the aerosol generating substrate to a downstream end of the aerosol generating substrate, wherein when the aerosol generating article is received in the heating chamber of the device, the airflow guiding element extends longitudinally into the substrate cavity, wherein the airflow channel is defined between an outer surface of the airflow guiding element and an inner surface of the aerosol generating substrate.

5. An aerosol generating system according to any one of the preceding claims, wherein the outer surface of the airflow directing element is textured or non-uniform.

6. An aerosol generating system according to any of the preceding claims, wherein the maximum width or diameter of the portion of the airflow directing element extending into the heating chamber is at least about 25% of the diameter of the heating chamber, preferably at least about 50% of the diameter of the heating chamber.

7. An aerosol generating system according to any one of the preceding claims, wherein the airflow directing element extends along at least 50% of the length of the heating chamber.

8. An aerosol generating system according to any of the preceding claims, wherein the airflow guiding element comprises an airflow inlet at a first position and an airflow outlet at a second position downstream of the first position, so that the airflow path is defined within and along the airflow guiding element.

9. An aerosol generating system according to any one of the preceding claims, wherein the airflow directing element comprises a hollow tube.

10. An aerosol generating system according to any one of the preceding claims, wherein the airflow directing element comprises a slender body, the slender body comprising a central core portion and an extension portion positioned along the core portion, wherein the extension portion extends outwardly from the core portion, preferably wherein the airflow directing element comprises at least two extension portions positioned along the core portion.

11. An aerosol-generating system according to any one of the preceding claims, wherein the wall thickness of the aerosol-generating substrate is between 5% and 40% of the outer diameter of the aerosol-generating substrate.

12. An aerosol generating system according to any one of the preceding claims, wherein the width or diameter of the airflow directing element is smaller than the diameter of the substrate cavity.

13. An aerosol generating system according to any one of the preceding claims, wherein the maximum width or diameter of the portion of the airflow directing element extending into the substrate cavity is at least about 25% of the diameter of the substrate cavity.

14. An aerosol-generating system according to any preceding claim, the aerosol-generating article being configured to extend beyond a mouth end of the aerosol-generating device when received within the aerosol-generating device.

15. An aerosol-generating system according to any one of the preceding claims, wherein the aerosol-generating article comprises a downstream section located downstream from the aerosol-generating substrate, the downstream section preferably comprising one or more of a mouthpiece element and a hollow tubular element.

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